From 7d4c7513a7f209cb303a608ac6e46b3f1dfc11ec Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Wed, 11 Nov 2015 01:48:01 +0000 Subject: upstream commit remove prototypes for long-gone s/key support; ok dtucker@ Upstream-ID: db5bed3c57118af986490ab23d399df807359a79 --- monitor_wrap.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'monitor_wrap.h') diff --git a/monitor_wrap.h b/monitor_wrap.h index de4a08f99..2b8c18d6a 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -1,4 +1,4 @@ -/* $OpenBSD: monitor_wrap.h,v 1.27 2015/05/01 03:23:51 djm Exp $ */ +/* $OpenBSD: monitor_wrap.h,v 1.28 2015/11/11 01:48:01 djm Exp $ */ /* * Copyright 2002 Niels Provos @@ -98,10 +98,6 @@ void mm_send_keystate(struct monitor*); int mm_bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); int mm_bsdauth_respond(void *, u_int, char **); -/* skey */ -int mm_skey_query(void *, char **, char **, u_int *, char ***, u_int **); -int mm_skey_respond(void *, u_int, char **); - /* zlib allocation hooks */ void mm_init_compression(struct mm_master *); -- cgit v1.2.3 From 6283cc72eb0e49a3470d30e07ca99a1ba9e89676 Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Mon, 30 Nov 2015 10:37:03 +1100 Subject: revert 7d4c7513: bring back S/Key prototypes (but leave RCSID changes) --- auth.h | 2 ++ monitor_wrap.h | 4 ++++ 2 files changed, 6 insertions(+) (limited to 'monitor_wrap.h') diff --git a/auth.h b/auth.h index fffbe6c07..b235906cf 100644 --- a/auth.h +++ b/auth.h @@ -180,6 +180,8 @@ int auth2_challenge(Authctxt *, char *); void auth2_challenge_stop(Authctxt *); int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); int bsdauth_respond(void *, u_int, char **); +int skey_query(void *, char **, char **, u_int *, char ***, u_int **); +int skey_respond(void *, u_int, char **); int allowed_user(struct passwd *); struct passwd * getpwnamallow(const char *user); diff --git a/monitor_wrap.h b/monitor_wrap.h index 2b8c18d6a..9a6aff684 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -98,6 +98,10 @@ void mm_send_keystate(struct monitor*); int mm_bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); int mm_bsdauth_respond(void *, u_int, char **); +/* skey */ +int mm_skey_query(void *, char **, char **, u_int *, char ***, u_int **); +int mm_skey_respond(void *, u_int, char **); + /* zlib allocation hooks */ void mm_init_compression(struct mm_master *); -- cgit v1.2.3 From 76c9fbbe35aabc1db977fb78e827644345e9442e Mon Sep 17 00:00:00 2001 From: "markus@openbsd.org" Date: Fri, 4 Dec 2015 16:41:28 +0000 Subject: upstream commit implement SHA2-{256,512} for RSASSA-PKCS1-v1_5 signatures (user and host auth) based on draft-rsa-dsa-sha2-256-03.txt and draft-ssh-ext-info-04.txt; with & ok djm@ Upstream-ID: cf82ce532b2733e5c4b34bb7b7c94835632db309 --- auth.h | 4 +- authfd.c | 18 +++++++- authfd.h | 6 ++- kex.c | 82 +++++++++++++++++++++++++++++++--- kex.h | 10 +++-- kexc25519s.c | 6 +-- kexdhs.c | 6 +-- kexecdhs.c | 6 +-- kexgexs.c | 6 +-- key.c | 6 +-- key.h | 5 ++- krl.c | 4 +- monitor.c | 12 ++--- monitor_wrap.c | 5 ++- monitor_wrap.h | 4 +- myproposal.h | 6 ++- packet.c | 5 ++- serverloop.c | 4 +- ssh-agent.c | 16 ++++++- ssh-keygen.c | 4 +- ssh-keysign.c | 5 ++- ssh-rsa.c | 136 +++++++++++++++++++++++++++++++++++++++++++++++---------- ssh2.h | 3 +- ssh_api.c | 16 +++---- sshconnect2.c | 126 ++++++++++++++++++++++++++++++++++++---------------- sshd.c | 18 +++++--- sshkey.c | 43 +++++++++--------- sshkey.h | 12 ++--- 28 files changed, 418 insertions(+), 156 deletions(-) (limited to 'monitor_wrap.h') diff --git a/auth.h b/auth.h index b235906cf..2160154f4 100644 --- a/auth.h +++ b/auth.h @@ -1,4 +1,4 @@ -/* $OpenBSD: auth.h,v 1.85 2015/11/11 01:48:01 djm Exp $ */ +/* $OpenBSD: auth.h,v 1.86 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. @@ -209,7 +209,7 @@ Key *get_hostkey_private_by_type(int, int, struct ssh *); int get_hostkey_index(Key *, int, struct ssh *); int ssh1_session_key(BIGNUM *); int sshd_hostkey_sign(Key *, Key *, u_char **, size_t *, - const u_char *, size_t, u_int); + const u_char *, size_t, const char *, u_int); /* debug messages during authentication */ void auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2))); diff --git a/authfd.c b/authfd.c index 12bf1251f..a634bcb81 100644 --- a/authfd.c +++ b/authfd.c @@ -1,4 +1,4 @@ -/* $OpenBSD: authfd.c,v 1.99 2015/09/02 07:51:12 jsg Exp $ */ +/* $OpenBSD: authfd.c,v 1.100 2015/12/04 16:41:28 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -426,11 +426,24 @@ ssh_decrypt_challenge(int sock, struct sshkey* key, BIGNUM *challenge, } #endif +/* encode signature algoritm in flag bits, so we can keep the msg format */ +static u_int +agent_encode_alg(struct sshkey *key, const char *alg) +{ + if (alg != NULL && key->type == KEY_RSA) { + if (strcmp(alg, "rsa-sha2-256") == 0) + return SSH_AGENT_RSA_SHA2_256; + else if (strcmp(alg, "rsa-sha2-512") == 0) + return SSH_AGENT_RSA_SHA2_512; + } + return 0; +} + /* ask agent to sign data, returns err.h code on error, 0 on success */ int ssh_agent_sign(int sock, struct sshkey *key, u_char **sigp, size_t *lenp, - const u_char *data, size_t datalen, u_int compat) + const u_char *data, size_t datalen, const char *alg, u_int compat) { struct sshbuf *msg; u_char *blob = NULL, type; @@ -449,6 +462,7 @@ ssh_agent_sign(int sock, struct sshkey *key, return SSH_ERR_ALLOC_FAIL; if ((r = sshkey_to_blob(key, &blob, &blen)) != 0) goto out; + flags |= agent_encode_alg(key, alg); if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 || (r = sshbuf_put_string(msg, blob, blen)) != 0 || (r = sshbuf_put_string(msg, data, datalen)) != 0 || diff --git a/authfd.h b/authfd.h index bea20c26b..4b417e3f4 100644 --- a/authfd.h +++ b/authfd.h @@ -1,4 +1,4 @@ -/* $OpenBSD: authfd.h,v 1.38 2015/01/14 20:05:27 djm Exp $ */ +/* $OpenBSD: authfd.h,v 1.39 2015/12/04 16:41:28 markus Exp $ */ /* * Author: Tatu Ylonen @@ -41,7 +41,7 @@ int ssh_decrypt_challenge(int sock, struct sshkey* key, BIGNUM *challenge, u_char session_id[16], u_char response[16]); int ssh_agent_sign(int sock, struct sshkey *key, u_char **sigp, size_t *lenp, - const u_char *data, size_t datalen, u_int compat); + const u_char *data, size_t datalen, const char *alg, u_int compat); /* Messages for the authentication agent connection. */ #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 @@ -86,5 +86,7 @@ int ssh_agent_sign(int sock, struct sshkey *key, #define SSH_COM_AGENT2_FAILURE 102 #define SSH_AGENT_OLD_SIGNATURE 0x01 +#define SSH_AGENT_RSA_SHA2_256 0x02 +#define SSH_AGENT_RSA_SHA2_512 0x04 #endif /* AUTHFD_H */ diff --git a/kex.c b/kex.c index b409f276b..c1371c432 100644 --- a/kex.c +++ b/kex.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.c,v 1.112 2015/11/13 04:39:35 djm Exp $ */ +/* $OpenBSD: kex.c,v 1.113 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * @@ -334,6 +334,20 @@ kex_reset_dispatch(struct ssh *ssh) ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit); } +static int +kex_send_ext_info(struct ssh *ssh) +{ + int r; + + if ((r = sshpkt_start(ssh, SSH2_MSG_EXT_INFO)) != 0 || + (r = sshpkt_put_u32(ssh, 1)) != 0 || + (r = sshpkt_put_cstring(ssh, "server-sig-algs")) != 0 || + (r = sshpkt_put_cstring(ssh, "rsa-sha2-256,rsa-sha2-512")) != 0 || + (r = sshpkt_send(ssh)) != 0) + return r; + return 0; +} + int kex_send_newkeys(struct ssh *ssh) { @@ -346,9 +360,51 @@ kex_send_newkeys(struct ssh *ssh) debug("SSH2_MSG_NEWKEYS sent"); debug("expecting SSH2_MSG_NEWKEYS"); ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_input_newkeys); + if (ssh->kex->ext_info_c) + if ((r = kex_send_ext_info(ssh)) != 0) + return r; return 0; } +int +kex_input_ext_info(int type, u_int32_t seq, void *ctxt) +{ + struct ssh *ssh = ctxt; + struct kex *kex = ssh->kex; + u_int32_t i, ninfo; + char *name, *val, *found; + int r; + + debug("SSH2_MSG_EXT_INFO received"); + ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &kex_protocol_error); + if ((r = sshpkt_get_u32(ssh, &ninfo)) != 0) + return r; + for (i = 0; i < ninfo; i++) { + if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0) + return r; + if ((r = sshpkt_get_cstring(ssh, &val, NULL)) != 0) { + free(name); + return r; + } + debug("%s: %s=<%s>", __func__, name, val); + if (strcmp(name, "server-sig-algs") == 0) { + found = match_list("rsa-sha2-256", val, NULL); + if (found) { + kex->rsa_sha2 = 256; + free(found); + } + found = match_list("rsa-sha2-512", val, NULL); + if (found) { + kex->rsa_sha2 = 512; + free(found); + } + } + free(name); + free(val); + } + return sshpkt_get_end(ssh); +} + static int kex_input_newkeys(int type, u_int32_t seq, void *ctxt) { @@ -531,6 +587,8 @@ kex_free(struct kex *kex) free(kex->client_version_string); free(kex->server_version_string); free(kex->failed_choice); + free(kex->hostkey_alg); + free(kex->name); free(kex); } @@ -627,17 +685,16 @@ choose_kex(struct kex *k, char *client, char *server) static int choose_hostkeyalg(struct kex *k, char *client, char *server) { - char *hostkeyalg = match_list(client, server, NULL); + k->hostkey_alg = match_list(client, server, NULL); debug("kex: host key algorithm: %s", - hostkeyalg ? hostkeyalg : "(no match)"); - if (hostkeyalg == NULL) + k->hostkey_alg ? k->hostkey_alg : "(no match)"); + if (k->hostkey_alg == NULL) return SSH_ERR_NO_HOSTKEY_ALG_MATCH; - k->hostkey_type = sshkey_type_from_name(hostkeyalg); + k->hostkey_type = sshkey_type_from_name(k->hostkey_alg); if (k->hostkey_type == KEY_UNSPEC) return SSH_ERR_INTERNAL_ERROR; - k->hostkey_nid = sshkey_ecdsa_nid_from_name(hostkeyalg); - free(hostkeyalg); + k->hostkey_nid = sshkey_ecdsa_nid_from_name(k->hostkey_alg); return 0; } @@ -702,6 +759,17 @@ kex_choose_conf(struct ssh *ssh) } } + /* Check whether client supports ext_info_c */ + if (kex->server) { + char *ext; + + ext = match_list("ext-info-c", peer[PROPOSAL_KEX_ALGS], NULL); + if (ext) { + kex->ext_info_c = 1; + free(ext); + } + } + /* Algorithm Negotiation */ if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS])) != 0) { diff --git a/kex.h b/kex.h index d71b53293..25ccf2e0e 100644 --- a/kex.h +++ b/kex.h @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.h,v 1.73 2015/07/30 00:01:34 djm Exp $ */ +/* $OpenBSD: kex.h,v 1.74 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. @@ -129,10 +129,13 @@ struct kex { u_int dh_need; int server; char *name; + char *hostkey_alg; int hostkey_type; int hostkey_nid; u_int kex_type; int roaming; + int rsa_sha2; + int ext_info_c; struct sshbuf *my; struct sshbuf *peer; sig_atomic_t done; @@ -146,8 +149,8 @@ struct kex { struct sshkey *(*load_host_public_key)(int, int, struct ssh *); struct sshkey *(*load_host_private_key)(int, int, struct ssh *); int (*host_key_index)(struct sshkey *, int, struct ssh *); - int (*sign)(struct sshkey *, struct sshkey *, - u_char **, size_t *, const u_char *, size_t, u_int); + int (*sign)(struct sshkey *, struct sshkey *, u_char **, size_t *, + const u_char *, size_t, const char *, u_int); int (*kex[KEX_MAX])(struct ssh *); /* kex specific state */ DH *dh; /* DH */ @@ -174,6 +177,7 @@ void kex_prop_free(char **); int kex_send_kexinit(struct ssh *); int kex_input_kexinit(int, u_int32_t, void *); +int kex_input_ext_info(int, u_int32_t, void *); int kex_derive_keys(struct ssh *, u_char *, u_int, const struct sshbuf *); int kex_derive_keys_bn(struct ssh *, u_char *, u_int, const BIGNUM *); int kex_send_newkeys(struct ssh *); diff --git a/kexc25519s.c b/kexc25519s.c index 240272533..4e77622b0 100644 --- a/kexc25519s.c +++ b/kexc25519s.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexc25519s.c,v 1.9 2015/04/27 00:37:53 dtucker Exp $ */ +/* $OpenBSD: kexc25519s.c,v 1.10 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * Copyright (c) 2010 Damien Miller. All rights reserved. @@ -134,8 +134,8 @@ input_kex_c25519_init(int type, u_int32_t seq, void *ctxt) } /* sign H */ - if ((r = kex->sign(server_host_private, server_host_public, - &signature, &slen, hash, hashlen, ssh->compat)) < 0) + if ((r = kex->sign(server_host_private, server_host_public, &signature, + &slen, hash, hashlen, kex->hostkey_alg, ssh->compat)) < 0) goto out; /* send server hostkey, ECDH pubkey 'Q_S' and signed H */ diff --git a/kexdhs.c b/kexdhs.c index de7c05b17..bf933e4c9 100644 --- a/kexdhs.c +++ b/kexdhs.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexdhs.c,v 1.22 2015/01/26 06:10:03 djm Exp $ */ +/* $OpenBSD: kexdhs.c,v 1.23 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * @@ -181,8 +181,8 @@ input_kex_dh_init(int type, u_int32_t seq, void *ctxt) } /* sign H */ - if ((r = kex->sign(server_host_private, server_host_public, - &signature, &slen, hash, hashlen, ssh->compat)) < 0) + if ((r = kex->sign(server_host_private, server_host_public, &signature, + &slen, hash, hashlen, kex->hostkey_alg, ssh->compat)) < 0) goto out; /* destroy_sensitive_data(); */ diff --git a/kexecdhs.c b/kexecdhs.c index 0adb80e6a..ccdbf70b1 100644 --- a/kexecdhs.c +++ b/kexecdhs.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexecdhs.c,v 1.14 2015/01/26 06:10:03 djm Exp $ */ +/* $OpenBSD: kexecdhs.c,v 1.15 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * Copyright (c) 2010 Damien Miller. All rights reserved. @@ -169,8 +169,8 @@ input_kex_ecdh_init(int type, u_int32_t seq, void *ctxt) } /* sign H */ - if ((r = kex->sign(server_host_private, server_host_public, - &signature, &slen, hash, hashlen, ssh->compat)) < 0) + if ((r = kex->sign(server_host_private, server_host_public, &signature, + &slen, hash, hashlen, kex->hostkey_alg, ssh->compat)) < 0) goto out; /* destroy_sensitive_data(); */ diff --git a/kexgexs.c b/kexgexs.c index ff6c6879e..8c5adf7e4 100644 --- a/kexgexs.c +++ b/kexgexs.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexgexs.c,v 1.25 2015/04/13 02:04:08 djm Exp $ */ +/* $OpenBSD: kexgexs.c,v 1.26 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000 Niels Provos. All rights reserved. * Copyright (c) 2001 Markus Friedl. All rights reserved. @@ -220,8 +220,8 @@ input_kex_dh_gex_init(int type, u_int32_t seq, void *ctxt) } /* sign H */ - if ((r = kex->sign(server_host_private, server_host_public, - &signature, &slen, hash, hashlen, ssh->compat)) < 0) + if ((r = kex->sign(server_host_private, server_host_public, &signature, + &slen, hash, hashlen, kex->hostkey_alg, ssh->compat)) < 0) goto out; /* destroy_sensitive_data(); */ diff --git a/key.c b/key.c index 0ba98b6f3..28d7c6207 100644 --- a/key.c +++ b/key.c @@ -1,4 +1,4 @@ -/* $OpenBSD: key.c,v 1.128 2015/07/03 03:43:18 djm Exp $ */ +/* $OpenBSD: key.c,v 1.129 2015/12/04 16:41:28 markus Exp $ */ /* * placed in the public domain */ @@ -132,7 +132,7 @@ key_to_blob(const Key *key, u_char **blobp, u_int *lenp) int key_sign(const Key *key, u_char **sigp, u_int *lenp, - const u_char *data, u_int datalen) + const u_char *data, u_int datalen, const char *alg) { int r; u_char *sig; @@ -143,7 +143,7 @@ key_sign(const Key *key, u_char **sigp, u_int *lenp, if (lenp != NULL) *lenp = 0; if ((r = sshkey_sign(key, &sig, &siglen, - data, datalen, datafellows)) != 0) { + data, datalen, alg, datafellows)) != 0) { fatal_on_fatal_errors(r, __func__, 0); error("%s: %s", __func__, ssh_err(r)); return -1; diff --git a/key.h b/key.h index 903bdf673..34c992bd3 100644 --- a/key.h +++ b/key.h @@ -1,4 +1,4 @@ -/* $OpenBSD: key.h,v 1.48 2015/07/03 03:43:18 djm Exp $ */ +/* $OpenBSD: key.h,v 1.49 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. @@ -84,7 +84,8 @@ int key_ec_validate_private(const EC_KEY *); Key *key_from_blob(const u_char *, u_int); int key_to_blob(const Key *, u_char **, u_int *); -int key_sign(const Key *, u_char **, u_int *, const u_char *, u_int); +int key_sign(const Key *, u_char **, u_int *, const u_char *, u_int, + const char *); int key_verify(const Key *, const u_char *, u_int, const u_char *, u_int); void key_private_serialize(const Key *, struct sshbuf *); diff --git a/krl.c b/krl.c index 570a4f747..0194f1c72 100644 --- a/krl.c +++ b/krl.c @@ -14,7 +14,7 @@ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ -/* $OpenBSD: krl.c,v 1.34 2015/09/02 07:51:12 jsg Exp $ */ +/* $OpenBSD: krl.c,v 1.35 2015/12/04 16:41:28 markus Exp $ */ #include "includes.h" @@ -772,7 +772,7 @@ ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf, goto out; if ((r = sshkey_sign(sign_keys[i], &sblob, &slen, - sshbuf_ptr(buf), sshbuf_len(buf), 0)) != 0) + sshbuf_ptr(buf), sshbuf_len(buf), NULL, 0)) != 0) goto out; KRL_DBG(("%s: signature sig len %zu", __func__, slen)); if ((r = sshbuf_put_string(buf, sblob, slen)) != 0) diff --git a/monitor.c b/monitor.c index 4060a6ec9..b3edd648b 100644 --- a/monitor.c +++ b/monitor.c @@ -1,4 +1,4 @@ -/* $OpenBSD: monitor.c,v 1.154 2015/10/20 23:24:25 mmcc Exp $ */ +/* $OpenBSD: monitor.c,v 1.155 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright 2002 Niels Provos * Copyright 2002 Markus Friedl @@ -688,14 +688,16 @@ mm_answer_sign(int sock, Buffer *m) struct sshbuf *sigbuf; u_char *p; u_char *signature; - size_t datlen, siglen; + char *alg; + size_t datlen, siglen, alglen; int r, keyid, is_proof = 0; const char proof_req[] = "hostkeys-prove-00@openssh.com"; debug3("%s", __func__); if ((r = sshbuf_get_u32(m, &keyid)) != 0 || - (r = sshbuf_get_string(m, &p, &datlen)) != 0) + (r = sshbuf_get_string(m, &p, &datlen)) != 0 || + (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); /* @@ -742,14 +744,14 @@ mm_answer_sign(int sock, Buffer *m) } if ((key = get_hostkey_by_index(keyid)) != NULL) { - if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, + if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg, datafellows)) != 0) fatal("%s: sshkey_sign failed: %s", __func__, ssh_err(r)); } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL && auth_sock > 0) { if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen, - p, datlen, datafellows)) != 0) { + p, datlen, alg, datafellows)) != 0) { fatal("%s: ssh_agent_sign failed: %s", __func__, ssh_err(r)); } diff --git a/monitor_wrap.c b/monitor_wrap.c index eac421ba1..d4bfaf372 100644 --- a/monitor_wrap.c +++ b/monitor_wrap.c @@ -1,4 +1,4 @@ -/* $OpenBSD: monitor_wrap.c,v 1.85 2015/05/01 03:23:51 djm Exp $ */ +/* $OpenBSD: monitor_wrap.c,v 1.86 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright 2002 Niels Provos * Copyright 2002 Markus Friedl @@ -218,7 +218,7 @@ mm_choose_dh(int min, int nbits, int max) int mm_key_sign(Key *key, u_char **sigp, u_int *lenp, - const u_char *data, u_int datalen) + const u_char *data, u_int datalen, const char *hostkey_alg) { struct kex *kex = *pmonitor->m_pkex; Buffer m; @@ -228,6 +228,7 @@ mm_key_sign(Key *key, u_char **sigp, u_int *lenp, buffer_init(&m); buffer_put_int(&m, kex->host_key_index(key, 0, active_state)); buffer_put_string(&m, data, datalen); + buffer_put_cstring(&m, hostkey_alg); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, &m); diff --git a/monitor_wrap.h b/monitor_wrap.h index 9a6aff684..eb820aeea 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -1,4 +1,4 @@ -/* $OpenBSD: monitor_wrap.h,v 1.28 2015/11/11 01:48:01 djm Exp $ */ +/* $OpenBSD: monitor_wrap.h,v 1.29 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright 2002 Niels Provos @@ -40,7 +40,7 @@ struct Authctxt; void mm_log_handler(LogLevel, const char *, void *); int mm_is_monitor(void); DH *mm_choose_dh(int, int, int); -int mm_key_sign(Key *, u_char **, u_int *, const u_char *, u_int); +int mm_key_sign(Key *, u_char **, u_int *, const u_char *, u_int, const char *); void mm_inform_authserv(char *, char *); struct passwd *mm_getpwnamallow(const char *); char *mm_auth2_read_banner(void); diff --git a/myproposal.h b/myproposal.h index 46e5b988d..c6429588a 100644 --- a/myproposal.h +++ b/myproposal.h @@ -1,4 +1,4 @@ -/* $OpenBSD: myproposal.h,v 1.47 2015/07/10 06:21:53 markus Exp $ */ +/* $OpenBSD: myproposal.h,v 1.48 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. @@ -101,7 +101,9 @@ "ssh-rsa-cert-v01@openssh.com," \ HOSTKEY_ECDSA_METHODS \ "ssh-ed25519," \ - "ssh-rsa" \ + "rsa-sha2-256," \ + "rsa-sha2-512," \ + "ssh-rsa" /* the actual algorithms */ diff --git a/packet.c b/packet.c index 4f6433b47..378906956 100644 --- a/packet.c +++ b/packet.c @@ -1,4 +1,4 @@ -/* $OpenBSD: packet.c,v 1.217 2015/11/08 21:59:11 djm Exp $ */ +/* $OpenBSD: packet.c,v 1.218 2015/12/04 16:41:28 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1215,7 +1215,8 @@ ssh_packet_send2(struct ssh *ssh) if ((type < SSH2_MSG_TRANSPORT_MIN) || (type > SSH2_MSG_TRANSPORT_MAX) || (type == SSH2_MSG_SERVICE_REQUEST) || - (type == SSH2_MSG_SERVICE_ACCEPT)) { + (type == SSH2_MSG_SERVICE_ACCEPT) || + (type == SSH2_MSG_EXT_INFO)) { debug("enqueue packet: %u", type); p = calloc(1, sizeof(*p)); if (p == NULL) diff --git a/serverloop.c b/serverloop.c index 4d0c0edb1..85fc8d3af 100644 --- a/serverloop.c +++ b/serverloop.c @@ -1,4 +1,4 @@ -/* $OpenBSD: serverloop.c,v 1.179 2015/11/28 06:41:03 djm Exp $ */ +/* $OpenBSD: serverloop.c,v 1.180 2015/12/04 16:41:28 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1201,7 +1201,7 @@ server_input_hostkeys_prove(struct sshbuf **respp) ssh->kex->session_id, ssh->kex->session_id_len)) != 0 || (r = sshkey_puts(key, sigbuf)) != 0 || (r = ssh->kex->sign(key_prv, key_pub, &sig, &slen, - sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), 0)) != 0 || + sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), NULL, 0)) != 0 || (r = sshbuf_put_string(resp, sig, slen)) != 0) { error("%s: couldn't prepare signature: %s", __func__, ssh_err(r)); diff --git a/ssh-agent.c b/ssh-agent.c index 2a7ae88f9..ed5dc571d 100644 --- a/ssh-agent.c +++ b/ssh-agent.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-agent.c,v 1.207 2015/12/02 08:30:50 doug Exp $ */ +/* $OpenBSD: ssh-agent.c,v 1.208 2015/12/04 16:41:28 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -368,6 +368,18 @@ process_authentication_challenge1(SocketEntry *e) } #endif +static char * +agent_decode_alg(struct sshkey *key, u_int flags) +{ + if (key->type == KEY_RSA) { + if (flags & SSH_AGENT_RSA_SHA2_256) + return "rsa-sha2-256"; + else if (flags & SSH_AGENT_RSA_SHA2_512) + return "rsa-sha2-512"; + } + return NULL; +} + /* ssh2 only */ static void process_sign_request2(SocketEntry *e) @@ -401,7 +413,7 @@ process_sign_request2(SocketEntry *e) goto send; } if ((r = sshkey_sign(id->key, &signature, &slen, - data, dlen, compat)) != 0) { + data, dlen, agent_decode_alg(key, flags), compat)) != 0) { error("%s: sshkey_sign: %s", __func__, ssh_err(ok)); goto send; } diff --git a/ssh-keygen.c b/ssh-keygen.c index f6a1c2847..6ac1fa603 100644 --- a/ssh-keygen.c +++ b/ssh-keygen.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-keygen.c,v 1.284 2015/11/28 06:50:52 deraadt Exp $ */ +/* $OpenBSD: ssh-keygen.c,v 1.285 2015/12/04 16:41:28 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1994 Tatu Ylonen , Espoo, Finland @@ -523,7 +523,7 @@ do_convert_private_ssh2_from_blob(u_char *blob, u_int blen) sshbuf_free(b); /* try the key */ - if (sshkey_sign(key, &sig, &slen, data, sizeof(data), 0) != 0 || + if (sshkey_sign(key, &sig, &slen, data, sizeof(data), NULL, 0) != 0 || sshkey_verify(key, sig, slen, data, sizeof(data), 0) != 0) { sshkey_free(key); free(sig); diff --git a/ssh-keysign.c b/ssh-keysign.c index 4c99609b2..1d49861ae 100644 --- a/ssh-keysign.c +++ b/ssh-keysign.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-keysign.c,v 1.50 2015/11/29 22:18:37 djm Exp $ */ +/* $OpenBSD: ssh-keysign.c,v 1.51 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2002 Markus Friedl. All rights reserved. * @@ -291,7 +291,8 @@ main(int argc, char **argv) sshkey_type(key), fp ? fp : ""); } - if ((r = sshkey_sign(keys[i], &signature, &slen, data, dlen, 0)) != 0) + if ((r = sshkey_sign(keys[i], &signature, &slen, data, dlen, NULL, 0)) + != 0) fatal("sshkey_sign failed: %s", ssh_err(r)); free(data); diff --git a/ssh-rsa.c b/ssh-rsa.c index 08090d14e..81dab05b3 100644 --- a/ssh-rsa.c +++ b/ssh-rsa.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-rsa.c,v 1.54 2015/09/09 00:52:44 djm Exp $ */ +/* $OpenBSD: ssh-rsa.c,v 1.55 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000, 2003 Markus Friedl * @@ -36,16 +36,60 @@ static int openssh_RSA_verify(int, u_char *, size_t, u_char *, size_t, RSA *); +static const char * +rsa_hash_alg_ident(int hash_alg) +{ + switch (hash_alg) { + case SSH_DIGEST_SHA1: + return "ssh-rsa"; + case SSH_DIGEST_SHA256: + return "rsa-sha2-256"; + case SSH_DIGEST_SHA512: + return "rsa-sha2-512"; + } + return NULL; +} + +static int +rsa_hash_alg_from_ident(const char *ident) +{ + if (ident == NULL || strlen(ident) == 0) + return SSH_DIGEST_SHA1; + if (strcmp(ident, "ssh-rsa") == 0) + return SSH_DIGEST_SHA1; + if (strcmp(ident, "rsa-sha2-256") == 0) + return SSH_DIGEST_SHA256; + if (strcmp(ident, "rsa-sha2-512") == 0) + return SSH_DIGEST_SHA512; + if (strncmp(ident, "ssh-rsa-cert", strlen("ssh-rsa-cert")) == 0) + return SSH_DIGEST_SHA1; + return -1; +} + +static int +rsa_hash_alg_nid(int type) +{ + switch (type) { + case SSH_DIGEST_SHA1: + return NID_sha1; + case SSH_DIGEST_SHA256: + return NID_sha256; + case SSH_DIGEST_SHA512: + return NID_sha512; + default: + return -1; + } +} + /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */ int ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, - const u_char *data, size_t datalen, u_int compat) + const u_char *data, size_t datalen, const char *alg_ident) { - int hash_alg; u_char digest[SSH_DIGEST_MAX_LENGTH], *sig = NULL; size_t slen; u_int dlen, len; - int nid, ret = SSH_ERR_INTERNAL_ERROR; + int nid, hash_alg, ret = SSH_ERR_INTERNAL_ERROR; struct sshbuf *b = NULL; if (lenp != NULL) @@ -53,16 +97,17 @@ ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, if (sigp != NULL) *sigp = NULL; - if (key == NULL || key->rsa == NULL || - sshkey_type_plain(key->type) != KEY_RSA) + hash_alg = rsa_hash_alg_from_ident(alg_ident); + if (key == NULL || key->rsa == NULL || hash_alg == -1 || + sshkey_type_plain(key->type) != KEY_RSA || + BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) return SSH_ERR_INVALID_ARGUMENT; slen = RSA_size(key->rsa); if (slen <= 0 || slen > SSHBUF_MAX_BIGNUM) return SSH_ERR_INVALID_ARGUMENT; /* hash the data */ - hash_alg = SSH_DIGEST_SHA1; - nid = NID_sha1; + nid = rsa_hash_alg_nid(hash_alg); if ((dlen = ssh_digest_bytes(hash_alg)) == 0) return SSH_ERR_INTERNAL_ERROR; if ((ret = ssh_digest_memory(hash_alg, data, datalen, @@ -91,7 +136,7 @@ ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, ret = SSH_ERR_ALLOC_FAIL; goto out; } - if ((ret = sshbuf_put_cstring(b, "ssh-rsa")) != 0 || + if ((ret = sshbuf_put_cstring(b, rsa_hash_alg_ident(hash_alg))) != 0 || (ret = sshbuf_put_string(b, sig, slen)) != 0) goto out; len = sshbuf_len(b); @@ -118,8 +163,7 @@ ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, int ssh_rsa_verify(const struct sshkey *key, - const u_char *signature, size_t signaturelen, - const u_char *data, size_t datalen, u_int compat) + const u_char *sig, size_t siglen, const u_char *data, size_t datalen) { char *ktype = NULL; int hash_alg, ret = SSH_ERR_INTERNAL_ERROR; @@ -132,13 +176,13 @@ ssh_rsa_verify(const struct sshkey *key, BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) return SSH_ERR_INVALID_ARGUMENT; - if ((b = sshbuf_from(signature, signaturelen)) == NULL) + if ((b = sshbuf_from(sig, siglen)) == NULL) return SSH_ERR_ALLOC_FAIL; if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } - if (strcmp("ssh-rsa", ktype) != 0) { + if ((hash_alg = rsa_hash_alg_from_ident(ktype)) == -1) { ret = SSH_ERR_KEY_TYPE_MISMATCH; goto out; } @@ -167,7 +211,6 @@ ssh_rsa_verify(const struct sshkey *key, explicit_bzero(sigblob, diff); len = modlen; } - hash_alg = SSH_DIGEST_SHA1; if ((dlen = ssh_digest_bytes(hash_alg)) == 0) { ret = SSH_ERR_INTERNAL_ERROR; goto out; @@ -196,6 +239,7 @@ ssh_rsa_verify(const struct sshkey *key, * http://www.rsasecurity.com/rsalabs/pkcs/pkcs-1/ * ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1.asn */ + /* * id-sha1 OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) * oiw(14) secsig(3) algorithms(2) 26 } @@ -209,6 +253,58 @@ static const u_char id_sha1[] = { 0x04, 0x14 /* Octet string, length 0x14 (20), followed by sha1 hash */ }; +/* + * See http://csrc.nist.gov/groups/ST/crypto_apps_infra/csor/algorithms.html + * id-sha256 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) + * organization(1) gov(101) csor(3) nistAlgorithm(4) hashAlgs(2) + * id-sha256(1) } + */ +static const u_char id_sha256[] = { + 0x30, 0x31, /* type Sequence, length 0x31 (49) */ + 0x30, 0x0d, /* type Sequence, length 0x0d (13) */ + 0x06, 0x09, /* type OID, length 0x09 */ + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, /* id-sha256 */ + 0x05, 0x00, /* NULL */ + 0x04, 0x20 /* Octet string, length 0x20 (32), followed by sha256 hash */ +}; + +/* + * See http://csrc.nist.gov/groups/ST/crypto_apps_infra/csor/algorithms.html + * id-sha512 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) + * organization(1) gov(101) csor(3) nistAlgorithm(4) hashAlgs(2) + * id-sha256(3) } + */ +static const u_char id_sha512[] = { + 0x30, 0x51, /* type Sequence, length 0x51 (81) */ + 0x30, 0x0d, /* type Sequence, length 0x0d (13) */ + 0x06, 0x09, /* type OID, length 0x09 */ + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, /* id-sha512 */ + 0x05, 0x00, /* NULL */ + 0x04, 0x40 /* Octet string, length 0x40 (64), followed by sha512 hash */ +}; + +static int +rsa_hash_alg_oid(int hash_alg, const u_char **oidp, size_t *oidlenp) +{ + switch (hash_alg) { + case SSH_DIGEST_SHA1: + *oidp = id_sha1; + *oidlenp = sizeof(id_sha1); + break; + case SSH_DIGEST_SHA256: + *oidp = id_sha256; + *oidlenp = sizeof(id_sha256); + break; + case SSH_DIGEST_SHA512: + *oidp = id_sha512; + *oidlenp = sizeof(id_sha512); + break; + default: + return SSH_ERR_INVALID_ARGUMENT; + } + return 0; +} + static int openssh_RSA_verify(int hash_alg, u_char *hash, size_t hashlen, u_char *sigbuf, size_t siglen, RSA *rsa) @@ -218,16 +314,10 @@ openssh_RSA_verify(int hash_alg, u_char *hash, size_t hashlen, const u_char *oid = NULL; u_char *decrypted = NULL; + if ((ret = rsa_hash_alg_oid(hash_alg, &oid, &oidlen)) != 0) + return ret; ret = SSH_ERR_INTERNAL_ERROR; - switch (hash_alg) { - case SSH_DIGEST_SHA1: - oid = id_sha1; - oidlen = sizeof(id_sha1); - hlen = 20; - break; - default: - goto done; - } + hlen = ssh_digest_bytes(hash_alg); if (hashlen != hlen) { ret = SSH_ERR_INVALID_ARGUMENT; goto done; diff --git a/ssh2.h b/ssh2.h index 59417e612..bdff6c5bd 100644 --- a/ssh2.h +++ b/ssh2.h @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh2.h,v 1.15 2014/01/29 06:18:35 djm Exp $ */ +/* $OpenBSD: ssh2.h,v 1.16 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. @@ -80,6 +80,7 @@ #define SSH2_MSG_DEBUG 4 #define SSH2_MSG_SERVICE_REQUEST 5 #define SSH2_MSG_SERVICE_ACCEPT 6 +#define SSH2_MSG_EXT_INFO 7 /* transport layer: alg negotiation */ diff --git a/ssh_api.c b/ssh_api.c index 6c712584f..f544f006b 100644 --- a/ssh_api.c +++ b/ssh_api.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh_api.c,v 1.4 2015/02/16 22:13:32 djm Exp $ */ +/* $OpenBSD: ssh_api.c,v 1.5 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2012 Markus Friedl. All rights reserved. * @@ -40,8 +40,8 @@ int _ssh_order_hostkeyalgs(struct ssh *); int _ssh_verify_host_key(struct sshkey *, struct ssh *); struct sshkey *_ssh_host_public_key(int, int, struct ssh *); struct sshkey *_ssh_host_private_key(int, int, struct ssh *); -int _ssh_host_key_sign(struct sshkey *, struct sshkey *, u_char **, - size_t *, const u_char *, size_t, u_int); +int _ssh_host_key_sign(struct sshkey *, struct sshkey *, + u_char **, size_t *, const u_char *, size_t, const char *, u_int); /* * stubs for the server side implementation of kex. @@ -49,7 +49,7 @@ int _ssh_host_key_sign(struct sshkey *, struct sshkey *, u_char **, */ int use_privsep = 0; int mm_sshkey_sign(struct sshkey *, u_char **, u_int *, - u_char *, u_int, u_int); + u_char *, u_int, char *, u_int); DH *mm_choose_dh(int, int, int); /* Define these two variables here so that they are part of the library */ @@ -58,7 +58,7 @@ u_int session_id2_len = 0; int mm_sshkey_sign(struct sshkey *key, u_char **sigp, u_int *lenp, - u_char *data, u_int datalen, u_int compat) + u_char *data, u_int datalen, char *alg, u_int compat) { return (-1); } @@ -530,8 +530,8 @@ _ssh_order_hostkeyalgs(struct ssh *ssh) int _ssh_host_key_sign(struct sshkey *privkey, struct sshkey *pubkey, - u_char **signature, size_t *slen, - const u_char *data, size_t dlen, u_int compat) + u_char **signature, size_t *slen, const u_char *data, size_t dlen, + const char *alg, u_int compat) { - return sshkey_sign(privkey, signature, slen, data, dlen, compat); + return sshkey_sign(privkey, signature, slen, data, dlen, alg, compat); } diff --git a/sshconnect2.c b/sshconnect2.c index d29f630f2..da1bd3847 100644 --- a/sshconnect2.c +++ b/sshconnect2.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshconnect2.c,v 1.230 2015/12/04 00:24:55 djm Exp $ */ +/* $OpenBSD: sshconnect2.c,v 1.231 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2008 Damien Miller. All rights reserved. @@ -157,14 +157,16 @@ void ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) { char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT }; + char *s; struct kex *kex; int r; xxx_host = host; xxx_hostaddr = hostaddr; - myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal( - options.kex_algorithms); + if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL) + fatal("%s: kex_names_cat", __func__); + myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s); myproposal[PROPOSAL_ENC_ALGS_CTOS] = compat_cipher_proposal(options.ciphers); myproposal[PROPOSAL_ENC_ALGS_STOC] = @@ -221,6 +223,11 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) debug("Roaming not allowed by server"); options.use_roaming = 0; } + /* remove ext-info from the KEX proposals for rekeying */ + myproposal[PROPOSAL_KEX_ALGS] = + compat_kex_proposal(options.kex_algorithms); + if ((r = kex_prop2buf(kex->my, myproposal)) != 0) + fatal("kex_prop2buf: %s", ssh_err(r)); session_id2 = kex->session_id; session_id2_len = kex->session_id_len; @@ -284,6 +291,8 @@ struct cauthmethod { int *batch_flag; /* flag in option struct that disables method */ }; +int input_userauth_service_accept(int, u_int32_t, void *); +int input_userauth_ext_info(int, u_int32_t, void *); int input_userauth_success(int, u_int32_t, void *); int input_userauth_success_unexpected(int, u_int32_t, void *); int input_userauth_failure(int, u_int32_t, void *); @@ -359,30 +368,12 @@ void ssh_userauth2(const char *local_user, const char *server_user, char *host, Sensitive *sensitive) { + struct ssh *ssh = active_state; Authctxt authctxt; - int type; + int r; if (options.challenge_response_authentication) options.kbd_interactive_authentication = 1; - - packet_start(SSH2_MSG_SERVICE_REQUEST); - packet_put_cstring("ssh-userauth"); - packet_send(); - debug("SSH2_MSG_SERVICE_REQUEST sent"); - packet_write_wait(); - type = packet_read(); - if (type != SSH2_MSG_SERVICE_ACCEPT) - fatal("Server denied authentication request: %d", type); - if (packet_remaining() > 0) { - char *reply = packet_get_string(NULL); - debug2("service_accept: %s", reply); - free(reply); - } else { - debug2("buggy server: service_accept w/o service"); - } - packet_check_eom(); - debug("SSH2_MSG_SERVICE_ACCEPT received"); - if (options.preferred_authentications == NULL) options.preferred_authentications = authmethods_get(); @@ -404,21 +395,63 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host, if (authctxt.method == NULL) fatal("ssh_userauth2: internal error: cannot send userauth none request"); - /* initial userauth request */ - userauth_none(&authctxt); + if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 || + (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 || + (r = sshpkt_send(ssh)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); - dispatch_init(&input_userauth_error); - dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); - dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); - dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); - dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ + ssh_dispatch_init(ssh, &input_userauth_error); + ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info); + ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept); + ssh_dispatch_run(ssh, DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ pubkey_cleanup(&authctxt); - dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); + ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); debug("Authentication succeeded (%s).", authctxt.method->name); } +/* ARGSUSED */ +int +input_userauth_service_accept(int type, u_int32_t seqnr, void *ctxt) +{ + Authctxt *authctxt = ctxt; + struct ssh *ssh = active_state; + int r; + + if (ssh_packet_remaining(ssh) > 0) { + char *reply; + + if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0) + goto out; + debug2("service_accept: %s", reply); + free(reply); + } else { + debug2("buggy server: service_accept w/o service"); + } + if ((r = sshpkt_get_end(ssh)) != 0) + goto out; + debug("SSH2_MSG_SERVICE_ACCEPT received"); + + /* initial userauth request */ + userauth_none(authctxt); + + ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error); + ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); + ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); + ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); + r = 0; + out: + return r; +} + +/* ARGSUSED */ +int +input_userauth_ext_info(int type, u_int32_t seqnr, void *ctxt) +{ + return kex_input_ext_info(type, seqnr, active_state); +} + void userauth(Authctxt *authctxt, char *authlist) { @@ -970,29 +1003,48 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) return 0; } +static const char * +identity_sign_encode(struct identity *id) +{ + struct ssh *ssh = active_state; + + if (id->key->type == KEY_RSA) { + switch (ssh->kex->rsa_sha2) { + case 256: + return "rsa-sha2-256"; + case 512: + return "rsa-sha2-512"; + } + } + return key_ssh_name(id->key); +} + static int identity_sign(struct identity *id, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, u_int compat) { Key *prv; int ret; + const char *alg; + + alg = identity_sign_encode(id); /* the agent supports this key */ if (id->agent_fd != -1) return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp, - data, datalen, compat); + data, datalen, alg, compat); /* * we have already loaded the private key or * the private key is stored in external hardware */ if (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT)) - return (sshkey_sign(id->key, sigp, lenp, data, datalen, + return (sshkey_sign(id->key, sigp, lenp, data, datalen, alg, compat)); /* load the private key from the file */ if ((prv = load_identity_file(id)) == NULL) return (-1); /* XXX return decent error code */ - ret = sshkey_sign(prv, sigp, lenp, data, datalen, compat); + ret = sshkey_sign(prv, sigp, lenp, data, datalen, alg, compat); sshkey_free(prv); return (ret); } @@ -1039,7 +1091,7 @@ sign_and_send_pubkey(Authctxt *authctxt, Identity *id) } else { buffer_put_cstring(&b, authctxt->method->name); buffer_put_char(&b, have_sig); - buffer_put_cstring(&b, key_ssh_name(id->key)); + buffer_put_cstring(&b, identity_sign_encode(id)); } buffer_put_string(&b, blob, bloblen); @@ -1139,7 +1191,7 @@ send_pubkey_test(Authctxt *authctxt, Identity *id) packet_put_cstring(authctxt->method->name); packet_put_char(have_sig); if (!(datafellows & SSH_BUG_PKAUTH)) - packet_put_cstring(key_ssh_name(id->key)); + packet_put_cstring(identity_sign_encode(id)); packet_put_string(blob, bloblen); free(blob); packet_send(); @@ -1743,7 +1795,7 @@ userauth_hostbased(Authctxt *authctxt) r = ssh_keysign(private, &sig, &siglen, sshbuf_ptr(b), sshbuf_len(b)); else if ((r = sshkey_sign(private, &sig, &siglen, - sshbuf_ptr(b), sshbuf_len(b), datafellows)) != 0) + sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0) debug("%s: sshkey_sign: %s", __func__, ssh_err(r)); if (r != 0) { error("sign using hostkey %s %s failed", diff --git a/sshd.c b/sshd.c index a823999b3..2f3f5b551 100644 --- a/sshd.c +++ b/sshd.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshd.c,v 1.460 2015/11/16 22:51:05 djm Exp $ */ +/* $OpenBSD: sshd.c,v 1.461 2015/12/04 16:41:28 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -816,6 +816,12 @@ list_hostkey_types(void) buffer_append(&b, ",", 1); p = key_ssh_name(key); buffer_append(&b, p, strlen(p)); + + /* for RSA we also support SHA2 signatures */ + if (key->type == KEY_RSA) { + p = ",rsa-sha2-512,rsa-sha2-256"; + buffer_append(&b, p, strlen(p)); + } break; } /* If the private key has a cert peer, then list that too */ @@ -2507,24 +2513,26 @@ do_ssh1_kex(void) int sshd_hostkey_sign(Key *privkey, Key *pubkey, u_char **signature, size_t *slen, - const u_char *data, size_t dlen, u_int flag) + const u_char *data, size_t dlen, const char *alg, u_int flag) { int r; u_int xxx_slen, xxx_dlen = dlen; if (privkey) { - if (PRIVSEP(key_sign(privkey, signature, &xxx_slen, data, xxx_dlen) < 0)) + if (PRIVSEP(key_sign(privkey, signature, &xxx_slen, data, xxx_dlen, + alg) < 0)) fatal("%s: key_sign failed", __func__); if (slen) *slen = xxx_slen; } else if (use_privsep) { - if (mm_key_sign(pubkey, signature, &xxx_slen, data, xxx_dlen) < 0) + if (mm_key_sign(pubkey, signature, &xxx_slen, data, xxx_dlen, + alg) < 0) fatal("%s: pubkey_sign failed", __func__); if (slen) *slen = xxx_slen; } else { if ((r = ssh_agent_sign(auth_sock, pubkey, signature, slen, - data, dlen, datafellows)) != 0) + data, dlen, alg, datafellows)) != 0) fatal("%s: ssh_agent_sign failed: %s", __func__, ssh_err(r)); } diff --git a/sshkey.c b/sshkey.c index dc16fe92c..587bf5b84 100644 --- a/sshkey.c +++ b/sshkey.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshkey.c,v 1.27 2015/11/19 01:08:55 djm Exp $ */ +/* $OpenBSD: sshkey.c,v 1.28 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * Copyright (c) 2008 Alexander von Gernler. All rights reserved. @@ -83,36 +83,39 @@ struct keytype { int type; int nid; int cert; + int sigonly; }; static const struct keytype keytypes[] = { - { "ssh-ed25519", "ED25519", KEY_ED25519, 0, 0 }, + { "ssh-ed25519", "ED25519", KEY_ED25519, 0, 0, 0 }, { "ssh-ed25519-cert-v01@openssh.com", "ED25519-CERT", - KEY_ED25519_CERT, 0, 1 }, + KEY_ED25519_CERT, 0, 1, 0 }, #ifdef WITH_OPENSSL - { NULL, "RSA1", KEY_RSA1, 0, 0 }, - { "ssh-rsa", "RSA", KEY_RSA, 0, 0 }, - { "ssh-dss", "DSA", KEY_DSA, 0, 0 }, + { NULL, "RSA1", KEY_RSA1, 0, 0, 0 }, + { "ssh-rsa", "RSA", KEY_RSA, 0, 0, 0 }, + { "rsa-sha2-256", "RSA", KEY_RSA, 0, 0, 1 }, + { "rsa-sha2-512", "RSA", KEY_RSA, 0, 0, 1 }, + { "ssh-dss", "DSA", KEY_DSA, 0, 0, 0 }, # ifdef OPENSSL_HAS_ECC - { "ecdsa-sha2-nistp256", "ECDSA", KEY_ECDSA, NID_X9_62_prime256v1, 0 }, - { "ecdsa-sha2-nistp384", "ECDSA", KEY_ECDSA, NID_secp384r1, 0 }, + { "ecdsa-sha2-nistp256", "ECDSA", KEY_ECDSA, NID_X9_62_prime256v1, 0, 0 }, + { "ecdsa-sha2-nistp384", "ECDSA", KEY_ECDSA, NID_secp384r1, 0, 0 }, # ifdef OPENSSL_HAS_NISTP521 - { "ecdsa-sha2-nistp521", "ECDSA", KEY_ECDSA, NID_secp521r1, 0 }, + { "ecdsa-sha2-nistp521", "ECDSA", KEY_ECDSA, NID_secp521r1, 0, 0 }, # endif /* OPENSSL_HAS_NISTP521 */ # endif /* OPENSSL_HAS_ECC */ - { "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", KEY_RSA_CERT, 0, 1 }, - { "ssh-dss-cert-v01@openssh.com", "DSA-CERT", KEY_DSA_CERT, 0, 1 }, + { "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", KEY_RSA_CERT, 0, 1, 0 }, + { "ssh-dss-cert-v01@openssh.com", "DSA-CERT", KEY_DSA_CERT, 0, 1, 0 }, # ifdef OPENSSL_HAS_ECC { "ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-CERT", - KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1 }, + KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1, 0 }, { "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT", - KEY_ECDSA_CERT, NID_secp384r1, 1 }, + KEY_ECDSA_CERT, NID_secp384r1, 1, 0 }, # ifdef OPENSSL_HAS_NISTP521 { "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT", - KEY_ECDSA_CERT, NID_secp521r1, 1 }, + KEY_ECDSA_CERT, NID_secp521r1, 1, 0 }, # endif /* OPENSSL_HAS_NISTP521 */ # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ - { NULL, NULL, -1, -1, 0 } + { NULL, NULL, -1, -1, 0, 0 } }; const char * @@ -200,7 +203,7 @@ key_alg_list(int certs_only, int plain_only) const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { - if (kt->name == NULL) + if (kt->name == NULL || kt->sigonly) continue; if ((certs_only && !kt->cert) || (plain_only && kt->cert)) continue; @@ -2174,7 +2177,7 @@ sshkey_froms(struct sshbuf *buf, struct sshkey **keyp) int sshkey_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, - const u_char *data, size_t datalen, u_int compat) + const u_char *data, size_t datalen, const char *alg, u_int compat) { if (sigp != NULL) *sigp = NULL; @@ -2194,7 +2197,7 @@ sshkey_sign(const struct sshkey *key, # endif /* OPENSSL_HAS_ECC */ case KEY_RSA_CERT: case KEY_RSA: - return ssh_rsa_sign(key, sigp, lenp, data, datalen, compat); + return ssh_rsa_sign(key, sigp, lenp, data, datalen, alg); #endif /* WITH_OPENSSL */ case KEY_ED25519: case KEY_ED25519_CERT: @@ -2226,7 +2229,7 @@ sshkey_verify(const struct sshkey *key, # endif /* OPENSSL_HAS_ECC */ case KEY_RSA_CERT: case KEY_RSA: - return ssh_rsa_verify(key, sig, siglen, data, dlen, compat); + return ssh_rsa_verify(key, sig, siglen, data, dlen); #endif /* WITH_OPENSSL */ case KEY_ED25519: case KEY_ED25519_CERT: @@ -2460,7 +2463,7 @@ sshkey_certify(struct sshkey *k, struct sshkey *ca) /* Sign the whole mess */ if ((ret = sshkey_sign(ca, &sig_blob, &sig_len, sshbuf_ptr(cert), - sshbuf_len(cert), 0)) != 0) + sshbuf_len(cert), NULL, 0)) != 0) goto out; /* Append signature and we are done */ diff --git a/sshkey.h b/sshkey.h index 5a8cccd42..a20a14f9e 100644 --- a/sshkey.h +++ b/sshkey.h @@ -1,4 +1,4 @@ -/* $OpenBSD: sshkey.h,v 1.11 2015/11/19 01:08:55 djm Exp $ */ +/* $OpenBSD: sshkey.h,v 1.12 2015/12/04 16:41:28 markus Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. @@ -169,7 +169,7 @@ int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *); int sshkey_putb_plain(const struct sshkey *, struct sshbuf *); int sshkey_sign(const struct sshkey *, u_char **, size_t *, - const u_char *, size_t, u_int); + const u_char *, size_t, const char *, u_int); int sshkey_verify(const struct sshkey *, const u_char *, size_t, const u_char *, size_t, u_int); @@ -193,11 +193,11 @@ int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type, const char *passphrase, struct sshkey **keyp, char **commentp); #ifdef SSHKEY_INTERNAL -int ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, - const u_char *data, size_t datalen, u_int compat); +int ssh_rsa_sign(const struct sshkey *key, + u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, + const char *ident); int ssh_rsa_verify(const struct sshkey *key, - const u_char *signature, size_t signaturelen, - const u_char *data, size_t datalen, u_int compat); + const u_char *sig, size_t siglen, const u_char *data, size_t datalen); int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, u_int compat); int ssh_dss_verify(const struct sshkey *key, -- cgit v1.2.3 From 374db1757fc18bd6647539b80977e6907a2cecd4 Mon Sep 17 00:00:00 2001 From: Simon Wilkinson Date: Sun, 9 Feb 2014 16:09:48 +0000 Subject: GSSAPI key exchange support This patch has been rejected upstream: "None of the OpenSSH developers are in favour of adding this, and this situation has not changed for several years. This is not a slight on Simon's patch, which is of fine quality, but just that a) we don't trust GSSAPI implementations that much and b) we don't like adding new KEX since they are pre-auth attack surface. This one is particularly scary, since it requires hooks out to typically root-owned system resources." However, quite a lot of people rely on this in Debian, and it's better to have it merged into the main openssh package rather than having separate -krb5 packages (as we used to have). It seems to have a generally good security history. Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1242 Last-Updated: 2016-01-04 Patch-Name: gssapi.patch --- ChangeLog.gssapi | 113 +++++++++++++++++++ Makefile.in | 3 +- auth-krb5.c | 17 ++- auth.c | 3 +- auth2-gss.c | 48 +++++++- auth2.c | 2 + clientloop.c | 15 ++- config.h.in | 6 + configure.ac | 24 ++++ gss-genr.c | 275 ++++++++++++++++++++++++++++++++++++++++++++- gss-serv-krb5.c | 85 ++++++++++++-- gss-serv.c | 185 +++++++++++++++++++++++++++--- kex.c | 16 +++ kex.h | 14 +++ kexgssc.c | 336 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ kexgsss.c | 295 ++++++++++++++++++++++++++++++++++++++++++++++++ monitor.c | 108 +++++++++++++++++- monitor.h | 3 + monitor_wrap.c | 47 +++++++- monitor_wrap.h | 4 +- readconf.c | 42 +++++++ readconf.h | 5 + servconf.c | 28 ++++- servconf.h | 2 + ssh-gss.h | 41 ++++++- ssh_config | 2 + ssh_config.5 | 32 ++++++ sshconnect2.c | 120 +++++++++++++++++++- sshd.c | 110 ++++++++++++++++++ sshd_config | 2 + sshd_config.5 | 10 ++ sshkey.c | 3 +- sshkey.h | 1 + 33 files changed, 1951 insertions(+), 46 deletions(-) create mode 100644 ChangeLog.gssapi create mode 100644 kexgssc.c create mode 100644 kexgsss.c (limited to 'monitor_wrap.h') diff --git a/ChangeLog.gssapi b/ChangeLog.gssapi new file mode 100644 index 000000000..f117a336a --- /dev/null +++ b/ChangeLog.gssapi @@ -0,0 +1,113 @@ +20110101 + - Finally update for OpenSSH 5.6p1 + - Add GSSAPIServerIdentity option from Jim Basney + +20100308 + - [ Makefile.in, key.c, key.h ] + Updates for OpenSSH 5.4p1 + - [ servconf.c ] + Include GSSAPI options in the sshd -T configuration dump, and flag + some older configuration options as being unsupported. Thanks to Colin + Watson. + - + +20100124 + - [ sshconnect2.c ] + Adapt to deal with additional element in Authmethod structure. Thanks to + Colin Watson + +20090615 + - [ gss-genr.c gss-serv.c kexgssc.c kexgsss.c monitor.c sshconnect2.c + sshd.c ] + Fix issues identified by Greg Hudson following a code review + Check return value of gss_indicate_mechs + Protect GSSAPI calls in monitor, so they can only be used if enabled + Check return values of bignum functions in key exchange + Use BN_clear_free to clear other side's DH value + Make ssh_gssapi_id_kex more robust + Only configure kex table pointers if GSSAPI is enabled + Don't leak mechanism list, or gss mechanism list + Cast data.length before printing + If serverkey isn't provided, use an empty string, rather than NULL + +20090201 + - [ gss-genr.c gss-serv.c kex.h kexgssc.c readconf.c readconf.h ssh-gss.h + ssh_config.5 sshconnet2.c ] + Add support for the GSSAPIClientIdentity option, which allows the user + to specify which GSSAPI identity to use to contact a given server + +20080404 + - [ gss-serv.c ] + Add code to actually implement GSSAPIStrictAcceptCheck, which had somehow + been omitted from a previous version of this patch. Reported by Borislav + Stoichkov + +20070317 + - [ gss-serv-krb5.c ] + Remove C99ism, where new_ccname was being declared in the middle of a + function + +20061220 + - [ servconf.c ] + Make default for GSSAPIStrictAcceptorCheck be Yes, to match previous, and + documented, behaviour. Reported by Dan Watson. + +20060910 + - [ gss-genr.c kexgssc.c kexgsss.c kex.h monitor.c sshconnect2.c sshd.c + ssh-gss.h ] + add support for gss-group14-sha1 key exchange mechanisms + - [ gss-serv.c servconf.c servconf.h sshd_config sshd_config.5 ] + Add GSSAPIStrictAcceptorCheck option to allow the disabling of + acceptor principal checking on multi-homed machines. + + - [ sshd_config ssh_config ] + Add settings for GSSAPIKeyExchange and GSSAPITrustDNS to the sample + configuration files + - [ kexgss.c kegsss.c sshconnect2.c sshd.c ] + Code cleanup. Replace strlen/xmalloc/snprintf sequences with xasprintf() + Limit length of error messages displayed by client + +20060909 + - [ gss-genr.c gss-serv.c ] + move ssh_gssapi_acquire_cred() and ssh_gssapi_server_ctx to be server + only, where they belong + + +20060829 + - [ gss-serv-krb5.c ] + Fix CCAPI credentials cache name when creating KRB5CCNAME environment + variable + +20060828 + - [ gss-genr.c ] + Avoid Heimdal context freeing problem + + +20060818 + - [ gss-genr.c ssh-gss.h sshconnect2.c ] + Make sure that SPENGO is disabled + + +20060421 + - [ gssgenr.c, sshconnect2.c ] + a few type changes (signed versus unsigned, int versus size_t) to + fix compiler errors/warnings + (from jbasney AT ncsa.uiuc.edu) + - [ kexgssc.c, sshconnect2.c ] + fix uninitialized variable warnings + (from jbasney AT ncsa.uiuc.edu) + - [ gssgenr.c ] + pass oid to gss_display_status (helpful when using GSSAPI mechglue) + (from jbasney AT ncsa.uiuc.edu) + + - [ gss-serv-krb5.c ] + #ifdef HAVE_GSSAPI_KRB5 should be #ifdef HAVE_GSSAPI_KRB5_H + (from jbasney AT ncsa.uiuc.edu) + + - [ readconf.c, readconf.h, ssh_config.5, sshconnect2.c + add client-side GssapiKeyExchange option + (from jbasney AT ncsa.uiuc.edu) + - [ sshconnect2.c ] + add support for GssapiTrustDns option for gssapi-with-mic + (from jbasney AT ncsa.uiuc.edu) + diff --git a/Makefile.in b/Makefile.in index d401787db..0954c631d 100644 --- a/Makefile.in +++ b/Makefile.in @@ -92,6 +92,7 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \ kex.o kexdh.o kexgex.o kexecdh.o kexc25519.o \ kexdhc.o kexgexc.o kexecdhc.o kexc25519c.o \ kexdhs.o kexgexs.o kexecdhs.o kexc25519s.o \ + kexgssc.o \ platform-pledge.o SSHOBJS= ssh.o readconf.o clientloop.o sshtty.o \ @@ -105,7 +106,7 @@ SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o auth-rsa.o auth-rh-rsa.o \ auth-skey.o auth-bsdauth.o auth2-hostbased.o auth2-kbdint.o \ auth2-none.o auth2-passwd.o auth2-pubkey.o \ monitor_mm.o monitor.o monitor_wrap.o auth-krb5.o \ - auth2-gss.o gss-serv.o gss-serv-krb5.o \ + auth2-gss.o gss-serv.o gss-serv-krb5.o kexgsss.o \ loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o \ sftp-server.o sftp-common.o \ sandbox-null.o sandbox-rlimit.o sandbox-systrace.o sandbox-darwin.o \ diff --git a/auth-krb5.c b/auth-krb5.c index d1c5a2f32..f019fb1a1 100644 --- a/auth-krb5.c +++ b/auth-krb5.c @@ -183,8 +183,13 @@ auth_krb5_password(Authctxt *authctxt, const char *password) len = strlen(authctxt->krb5_ticket_file) + 6; authctxt->krb5_ccname = xmalloc(len); +#ifdef USE_CCAPI + snprintf(authctxt->krb5_ccname, len, "API:%s", + authctxt->krb5_ticket_file); +#else snprintf(authctxt->krb5_ccname, len, "FILE:%s", authctxt->krb5_ticket_file); +#endif #ifdef USE_PAM if (options.use_pam) @@ -241,15 +246,22 @@ krb5_cleanup_proc(Authctxt *authctxt) #ifndef HEIMDAL krb5_error_code ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) { - int tmpfd, ret, oerrno; + int ret, oerrno; char ccname[40]; mode_t old_umask; +#ifdef USE_CCAPI + char cctemplate[] = "API:krb5cc_%d"; +#else + char cctemplate[] = "FILE:/tmp/krb5cc_%d_XXXXXXXXXX"; + int tmpfd; +#endif ret = snprintf(ccname, sizeof(ccname), - "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid()); + cctemplate, geteuid()); if (ret < 0 || (size_t)ret >= sizeof(ccname)) return ENOMEM; +#ifndef USE_CCAPI old_umask = umask(0177); tmpfd = mkstemp(ccname + strlen("FILE:")); oerrno = errno; @@ -266,6 +278,7 @@ ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) { return oerrno; } close(tmpfd); +#endif return (krb5_cc_resolve(ctx, ccname, ccache)); } diff --git a/auth.c b/auth.c index 214c2c708..bd6a026a1 100644 --- a/auth.c +++ b/auth.c @@ -354,7 +354,8 @@ auth_root_allowed(const char *method) case PERMIT_NO_PASSWD: if (strcmp(method, "publickey") == 0 || strcmp(method, "hostbased") == 0 || - strcmp(method, "gssapi-with-mic") == 0) + strcmp(method, "gssapi-with-mic") == 0 || + strcmp(method, "gssapi-keyex") == 0) return 1; break; case PERMIT_FORCED_ONLY: diff --git a/auth2-gss.c b/auth2-gss.c index 1ca835773..3b5036dfd 100644 --- a/auth2-gss.c +++ b/auth2-gss.c @@ -1,7 +1,7 @@ /* $OpenBSD: auth2-gss.c,v 1.22 2015/01/19 20:07:45 markus Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -53,6 +53,40 @@ static int input_gssapi_mic(int type, u_int32_t plen, void *ctxt); static int input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt); static int input_gssapi_errtok(int, u_int32_t, void *); +/* + * The 'gssapi_keyex' userauth mechanism. + */ +static int +userauth_gsskeyex(Authctxt *authctxt) +{ + int authenticated = 0; + Buffer b; + gss_buffer_desc mic, gssbuf; + u_int len; + + mic.value = packet_get_string(&len); + mic.length = len; + + packet_check_eom(); + + ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service, + "gssapi-keyex"); + + gssbuf.value = buffer_ptr(&b); + gssbuf.length = buffer_len(&b); + + /* gss_kex_context is NULL with privsep, so we can't check it here */ + if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, + &gssbuf, &mic)))) + authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user, + authctxt->pw)); + + buffer_free(&b); + free(mic.value); + + return (authenticated); +} + /* * We only support those mechanisms that we know about (ie ones that we know * how to check local user kuserok and the like) @@ -238,7 +272,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt) packet_check_eom(); - authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); + authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user, + authctxt->pw)); authctxt->postponed = 0; dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); @@ -274,7 +309,8 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt) gssbuf.length = buffer_len(&b); if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic)))) - authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); + authenticated = + PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw)); else logit("GSSAPI MIC check failed"); @@ -290,6 +326,12 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt) return 0; } +Authmethod method_gsskeyex = { + "gssapi-keyex", + userauth_gsskeyex, + &options.gss_authentication +}; + Authmethod method_gssapi = { "gssapi-with-mic", userauth_gssapi, diff --git a/auth2.c b/auth2.c index 717796228..3f49bdca0 100644 --- a/auth2.c +++ b/auth2.c @@ -70,6 +70,7 @@ extern Authmethod method_passwd; extern Authmethod method_kbdint; extern Authmethod method_hostbased; #ifdef GSSAPI +extern Authmethod method_gsskeyex; extern Authmethod method_gssapi; #endif @@ -77,6 +78,7 @@ Authmethod *authmethods[] = { &method_none, &method_pubkey, #ifdef GSSAPI + &method_gsskeyex, &method_gssapi, #endif &method_passwd, diff --git a/clientloop.c b/clientloop.c index 9820455c4..1567e4a2f 100644 --- a/clientloop.c +++ b/clientloop.c @@ -114,6 +114,10 @@ #include "ssherr.h" #include "hostfile.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* import options */ extern Options options; @@ -1662,9 +1666,18 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) break; /* Do channel operations unless rekeying in progress. */ - if (!ssh_packet_is_rekeying(active_state)) + if (!ssh_packet_is_rekeying(active_state)) { channel_after_select(readset, writeset); +#ifdef GSSAPI + if (options.gss_renewal_rekey && + ssh_gssapi_credentials_updated(NULL)) { + debug("credentials updated - forcing rekey"); + need_rekeying = 1; + } +#endif + } + /* Buffer input from the connection. */ client_process_net_input(readset); diff --git a/config.h.in b/config.h.in index 89bf1b0ff..621c1396e 100644 --- a/config.h.in +++ b/config.h.in @@ -1641,6 +1641,9 @@ /* Use btmp to log bad logins */ #undef USE_BTMP +/* platform uses an in-memory credentials cache */ +#undef USE_CCAPI + /* Use libedit for sftp */ #undef USE_LIBEDIT @@ -1656,6 +1659,9 @@ /* Use PIPES instead of a socketpair() */ #undef USE_PIPES +/* platform has the Security Authorization Session API */ +#undef USE_SECURITY_SESSION_API + /* Define if you have Solaris privileges */ #undef USE_SOLARIS_PRIVS diff --git a/configure.ac b/configure.ac index 7258cc0e5..5f1ff740f 100644 --- a/configure.ac +++ b/configure.ac @@ -632,6 +632,30 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16)) [Use tunnel device compatibility to OpenBSD]) AC_DEFINE([SSH_TUN_PREPEND_AF], [1], [Prepend the address family to IP tunnel traffic]) + AC_MSG_CHECKING([if we have the Security Authorization Session API]) + AC_TRY_COMPILE([#include ], + [SessionCreate(0, 0);], + [ac_cv_use_security_session_api="yes" + AC_DEFINE([USE_SECURITY_SESSION_API], [1], + [platform has the Security Authorization Session API]) + LIBS="$LIBS -framework Security" + AC_MSG_RESULT([yes])], + [ac_cv_use_security_session_api="no" + AC_MSG_RESULT([no])]) + AC_MSG_CHECKING([if we have an in-memory credentials cache]) + AC_TRY_COMPILE( + [#include ], + [cc_context_t c; + (void) cc_initialize (&c, 0, NULL, NULL);], + [AC_DEFINE([USE_CCAPI], [1], + [platform uses an in-memory credentials cache]) + LIBS="$LIBS -framework Security" + AC_MSG_RESULT([yes]) + if test "x$ac_cv_use_security_session_api" = "xno"; then + AC_MSG_ERROR([*** Need a security framework to use the credentials cache API ***]) + fi], + [AC_MSG_RESULT([no])] + ) m4_pattern_allow([AU_IPv]) AC_CHECK_DECL([AU_IPv4], [], AC_DEFINE([AU_IPv4], [0], [System only supports IPv4 audit records]) diff --git a/gss-genr.c b/gss-genr.c index d617d600a..b4eca3feb 100644 --- a/gss-genr.c +++ b/gss-genr.c @@ -1,7 +1,7 @@ /* $OpenBSD: gss-genr.c,v 1.23 2015/01/20 23:14:00 deraadt Exp $ */ /* - * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -41,12 +41,167 @@ #include "buffer.h" #include "log.h" #include "ssh2.h" +#include "cipher.h" +#include "key.h" +#include "kex.h" +#include #include "ssh-gss.h" extern u_char *session_id2; extern u_int session_id2_len; +typedef struct { + char *encoded; + gss_OID oid; +} ssh_gss_kex_mapping; + +/* + * XXX - It would be nice to find a more elegant way of handling the + * XXX passing of the key exchange context to the userauth routines + */ + +Gssctxt *gss_kex_context = NULL; + +static ssh_gss_kex_mapping *gss_enc2oid = NULL; + +int +ssh_gssapi_oid_table_ok(void) { + return (gss_enc2oid != NULL); +} + +/* + * Return a list of the gss-group1-sha1 mechanisms supported by this program + * + * We test mechanisms to ensure that we can use them, to avoid starting + * a key exchange with a bad mechanism + */ + +char * +ssh_gssapi_client_mechanisms(const char *host, const char *client) { + gss_OID_set gss_supported; + OM_uint32 min_status; + + if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported))) + return NULL; + + return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism, + host, client)); +} + +char * +ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check, + const char *host, const char *client) { + Buffer buf; + size_t i; + int oidpos, enclen; + char *mechs, *encoded; + u_char digest[EVP_MAX_MD_SIZE]; + char deroid[2]; + const EVP_MD *evp_md = EVP_md5(); + EVP_MD_CTX md; + + if (gss_enc2oid != NULL) { + for (i = 0; gss_enc2oid[i].encoded != NULL; i++) + free(gss_enc2oid[i].encoded); + free(gss_enc2oid); + } + + gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) * + (gss_supported->count + 1)); + + buffer_init(&buf); + + oidpos = 0; + for (i = 0; i < gss_supported->count; i++) { + if (gss_supported->elements[i].length < 128 && + (*check)(NULL, &(gss_supported->elements[i]), host, client)) { + + deroid[0] = SSH_GSS_OIDTYPE; + deroid[1] = gss_supported->elements[i].length; + + EVP_DigestInit(&md, evp_md); + EVP_DigestUpdate(&md, deroid, 2); + EVP_DigestUpdate(&md, + gss_supported->elements[i].elements, + gss_supported->elements[i].length); + EVP_DigestFinal(&md, digest, NULL); + + encoded = xmalloc(EVP_MD_size(evp_md) * 2); + enclen = __b64_ntop(digest, EVP_MD_size(evp_md), + encoded, EVP_MD_size(evp_md) * 2); + + if (oidpos != 0) + buffer_put_char(&buf, ','); + + buffer_append(&buf, KEX_GSS_GEX_SHA1_ID, + sizeof(KEX_GSS_GEX_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + buffer_put_char(&buf, ','); + buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID, + sizeof(KEX_GSS_GRP1_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + buffer_put_char(&buf, ','); + buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID, + sizeof(KEX_GSS_GRP14_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + + gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]); + gss_enc2oid[oidpos].encoded = encoded; + oidpos++; + } + } + gss_enc2oid[oidpos].oid = NULL; + gss_enc2oid[oidpos].encoded = NULL; + + buffer_put_char(&buf, '\0'); + + mechs = xmalloc(buffer_len(&buf)); + buffer_get(&buf, mechs, buffer_len(&buf)); + buffer_free(&buf); + + if (strlen(mechs) == 0) { + free(mechs); + mechs = NULL; + } + + return (mechs); +} + +gss_OID +ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) { + int i = 0; + + switch (kex_type) { + case KEX_GSS_GRP1_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GRP1_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1; + break; + case KEX_GSS_GRP14_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GRP14_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1; + break; + case KEX_GSS_GEX_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GEX_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1; + break; + default: + return GSS_C_NO_OID; + } + + while (gss_enc2oid[i].encoded != NULL && + strcmp(name, gss_enc2oid[i].encoded) != 0) + i++; + + if (gss_enc2oid[i].oid != NULL && ctx != NULL) + ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid); + + return gss_enc2oid[i].oid; +} + /* Check that the OID in a data stream matches that in the context */ int ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len) @@ -199,7 +354,7 @@ ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok, } ctx->major = gss_init_sec_context(&ctx->minor, - GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid, + ctx->client_creds, &ctx->context, ctx->name, ctx->oid, GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag, 0, NULL, recv_tok, NULL, send_tok, flags, NULL); @@ -228,9 +383,43 @@ ssh_gssapi_import_name(Gssctxt *ctx, const char *host) return (ctx->major); } +OM_uint32 +ssh_gssapi_client_identity(Gssctxt *ctx, const char *name) +{ + gss_buffer_desc gssbuf; + gss_name_t gssname; + OM_uint32 status; + gss_OID_set oidset; + + gssbuf.value = (void *) name; + gssbuf.length = strlen(gssbuf.value); + + gss_create_empty_oid_set(&status, &oidset); + gss_add_oid_set_member(&status, ctx->oid, &oidset); + + ctx->major = gss_import_name(&ctx->minor, &gssbuf, + GSS_C_NT_USER_NAME, &gssname); + + if (!ctx->major) + ctx->major = gss_acquire_cred(&ctx->minor, + gssname, 0, oidset, GSS_C_INITIATE, + &ctx->client_creds, NULL, NULL); + + gss_release_name(&status, &gssname); + gss_release_oid_set(&status, &oidset); + + if (ctx->major) + ssh_gssapi_error(ctx); + + return(ctx->major); +} + OM_uint32 ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash) { + if (ctx == NULL) + return -1; + if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context, GSS_C_QOP_DEFAULT, buffer, hash))) ssh_gssapi_error(ctx); @@ -238,6 +427,19 @@ ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash) return (ctx->major); } +/* Priviledged when used by server */ +OM_uint32 +ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) +{ + if (ctx == NULL) + return -1; + + ctx->major = gss_verify_mic(&ctx->minor, ctx->context, + gssbuf, gssmic, NULL); + + return (ctx->major); +} + void ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service, const char *context) @@ -251,11 +453,16 @@ ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service, } int -ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host) +ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host, + const char *client) { gss_buffer_desc token = GSS_C_EMPTY_BUFFER; OM_uint32 major, minor; gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"}; + Gssctxt *intctx = NULL; + + if (ctx == NULL) + ctx = &intctx; /* RFC 4462 says we MUST NOT do SPNEGO */ if (oid->length == spnego_oid.length && @@ -265,6 +472,10 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host) ssh_gssapi_build_ctx(ctx); ssh_gssapi_set_oid(*ctx, oid); major = ssh_gssapi_import_name(*ctx, host); + + if (!GSS_ERROR(major) && client) + major = ssh_gssapi_client_identity(*ctx, client); + if (!GSS_ERROR(major)) { major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token, NULL); @@ -274,10 +485,66 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host) GSS_C_NO_BUFFER); } - if (GSS_ERROR(major)) + if (GSS_ERROR(major) || intctx != NULL) ssh_gssapi_delete_ctx(ctx); return (!GSS_ERROR(major)); } +int +ssh_gssapi_credentials_updated(Gssctxt *ctxt) { + static gss_name_t saved_name = GSS_C_NO_NAME; + static OM_uint32 saved_lifetime = 0; + static gss_OID saved_mech = GSS_C_NO_OID; + static gss_name_t name; + static OM_uint32 last_call = 0; + OM_uint32 lifetime, now, major, minor; + int equal; + + now = time(NULL); + + if (ctxt) { + debug("Rekey has happened - updating saved versions"); + + if (saved_name != GSS_C_NO_NAME) + gss_release_name(&minor, &saved_name); + + major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL, + &saved_name, &saved_lifetime, NULL, NULL); + + if (!GSS_ERROR(major)) { + saved_mech = ctxt->oid; + saved_lifetime+= now; + } else { + /* Handle the error */ + } + return 0; + } + + if (now - last_call < 10) + return 0; + + last_call = now; + + if (saved_mech == GSS_C_NO_OID) + return 0; + + major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL, + &name, &lifetime, NULL, NULL); + if (major == GSS_S_CREDENTIALS_EXPIRED) + return 0; + else if (GSS_ERROR(major)) + return 0; + + major = gss_compare_name(&minor, saved_name, name, &equal); + gss_release_name(&minor, &name); + if (GSS_ERROR(major)) + return 0; + + if (equal && (saved_lifetime < lifetime + now - 10)) + return 1; + + return 0; +} + #endif /* GSSAPI */ diff --git a/gss-serv-krb5.c b/gss-serv-krb5.c index 795992d9f..fd8b37183 100644 --- a/gss-serv-krb5.c +++ b/gss-serv-krb5.c @@ -1,7 +1,7 @@ /* $OpenBSD: gss-serv-krb5.c,v 1.8 2013/07/20 01:55:13 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -121,8 +121,8 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) krb5_error_code problem; krb5_principal princ; OM_uint32 maj_status, min_status; - int len; const char *errmsg; + const char *new_ccname; if (client->creds == NULL) { debug("No credentials stored"); @@ -181,11 +181,16 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) return; } - client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache)); + new_ccname = krb5_cc_get_name(krb_context, ccache); + client->store.envvar = "KRB5CCNAME"; - len = strlen(client->store.filename) + 6; - client->store.envval = xmalloc(len); - snprintf(client->store.envval, len, "FILE:%s", client->store.filename); +#ifdef USE_CCAPI + xasprintf(&client->store.envval, "API:%s", new_ccname); + client->store.filename = NULL; +#else + xasprintf(&client->store.envval, "FILE:%s", new_ccname); + client->store.filename = xstrdup(new_ccname); +#endif #ifdef USE_PAM if (options.use_pam) @@ -197,6 +202,71 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) return; } +int +ssh_gssapi_krb5_updatecreds(ssh_gssapi_ccache *store, + ssh_gssapi_client *client) +{ + krb5_ccache ccache = NULL; + krb5_principal principal = NULL; + char *name = NULL; + krb5_error_code problem; + OM_uint32 maj_status, min_status; + + if ((problem = krb5_cc_resolve(krb_context, store->envval, &ccache))) { + logit("krb5_cc_resolve(): %.100s", + krb5_get_err_text(krb_context, problem)); + return 0; + } + + /* Find out who the principal in this cache is */ + if ((problem = krb5_cc_get_principal(krb_context, ccache, + &principal))) { + logit("krb5_cc_get_principal(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_cc_close(krb_context, ccache); + return 0; + } + + if ((problem = krb5_unparse_name(krb_context, principal, &name))) { + logit("krb5_unparse_name(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + return 0; + } + + + if (strcmp(name,client->exportedname.value)!=0) { + debug("Name in local credentials cache differs. Not storing"); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + krb5_free_unparsed_name(krb_context, name); + return 0; + } + krb5_free_unparsed_name(krb_context, name); + + /* Name matches, so lets get on with it! */ + + if ((problem = krb5_cc_initialize(krb_context, ccache, principal))) { + logit("krb5_cc_initialize(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + return 0; + } + + krb5_free_principal(krb_context, principal); + + if ((maj_status = gss_krb5_copy_ccache(&min_status, client->creds, + ccache))) { + logit("gss_krb5_copy_ccache() failed. Sorry!"); + krb5_cc_close(krb_context, ccache); + return 0; + } + + return 1; +} + ssh_gssapi_mech gssapi_kerberos_mech = { "toWM5Slw5Ew8Mqkay+al2g==", "Kerberos", @@ -204,7 +274,8 @@ ssh_gssapi_mech gssapi_kerberos_mech = { NULL, &ssh_gssapi_krb5_userok, NULL, - &ssh_gssapi_krb5_storecreds + &ssh_gssapi_krb5_storecreds, + &ssh_gssapi_krb5_updatecreds }; #endif /* KRB5 */ diff --git a/gss-serv.c b/gss-serv.c index 53993d674..2f6baf70d 100644 --- a/gss-serv.c +++ b/gss-serv.c @@ -1,7 +1,7 @@ /* $OpenBSD: gss-serv.c,v 1.29 2015/05/22 03:50:02 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -45,17 +45,22 @@ #include "session.h" #include "misc.h" #include "servconf.h" +#include "uidswap.h" #include "ssh-gss.h" +#include "monitor_wrap.h" + +extern ServerOptions options; extern ServerOptions options; static ssh_gssapi_client gssapi_client = { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER, - GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL, NULL}}; + GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, NULL, + {NULL, NULL, NULL, NULL, NULL}, 0, 0}; ssh_gssapi_mech gssapi_null_mech = - { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL}; + { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL}; #ifdef KRB5 extern ssh_gssapi_mech gssapi_kerberos_mech; @@ -141,6 +146,29 @@ ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid) return (ssh_gssapi_acquire_cred(*ctx)); } +/* Unprivileged */ +char * +ssh_gssapi_server_mechanisms(void) { + gss_OID_set supported; + + ssh_gssapi_supported_oids(&supported); + return (ssh_gssapi_kex_mechs(supported, &ssh_gssapi_server_check_mech, + NULL, NULL)); +} + +/* Unprivileged */ +int +ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data, + const char *dummy) { + Gssctxt *ctx = NULL; + int res; + + res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid))); + ssh_gssapi_delete_ctx(&ctx); + + return (res); +} + /* Unprivileged */ void ssh_gssapi_supported_oids(gss_OID_set *oidset) @@ -151,7 +179,9 @@ ssh_gssapi_supported_oids(gss_OID_set *oidset) gss_OID_set supported; gss_create_empty_oid_set(&min_status, oidset); - gss_indicate_mechs(&min_status, &supported); + + if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported))) + return; while (supported_mechs[i]->name != NULL) { if (GSS_ERROR(gss_test_oid_set_member(&min_status, @@ -277,8 +307,48 @@ OM_uint32 ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) { int i = 0; + int equal = 0; + gss_name_t new_name = GSS_C_NO_NAME; + gss_buffer_desc ename = GSS_C_EMPTY_BUFFER; + + if (options.gss_store_rekey && client->used && ctx->client_creds) { + if (client->mech->oid.length != ctx->oid->length || + (memcmp(client->mech->oid.elements, + ctx->oid->elements, ctx->oid->length) !=0)) { + debug("Rekeyed credentials have different mechanism"); + return GSS_S_COMPLETE; + } + + if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor, + ctx->client_creds, ctx->oid, &new_name, + NULL, NULL, NULL))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + + ctx->major = gss_compare_name(&ctx->minor, client->name, + new_name, &equal); + + if (GSS_ERROR(ctx->major)) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + + if (!equal) { + debug("Rekeyed credentials have different name"); + return GSS_S_COMPLETE; + } - gss_buffer_desc ename; + debug("Marking rekeyed credentials for export"); + + gss_release_name(&ctx->minor, &client->name); + gss_release_cred(&ctx->minor, &client->creds); + client->name = new_name; + client->creds = ctx->client_creds; + ctx->client_creds = GSS_C_NO_CREDENTIAL; + client->updated = 1; + return GSS_S_COMPLETE; + } client->mech = NULL; @@ -293,6 +363,13 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) if (client->mech == NULL) return GSS_S_FAILURE; + if (ctx->client_creds && + (ctx->major = gss_inquire_cred_by_mech(&ctx->minor, + ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + if ((ctx->major = gss_display_name(&ctx->minor, ctx->client, &client->displayname, NULL))) { ssh_gssapi_error(ctx); @@ -310,6 +387,8 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) return (ctx->major); } + gss_release_buffer(&ctx->minor, &ename); + /* We can't copy this structure, so we just move the pointer to it */ client->creds = ctx->client_creds; ctx->client_creds = GSS_C_NO_CREDENTIAL; @@ -357,7 +436,7 @@ ssh_gssapi_do_child(char ***envp, u_int *envsizep) /* Privileged */ int -ssh_gssapi_userok(char *user) +ssh_gssapi_userok(char *user, struct passwd *pw) { OM_uint32 lmin; @@ -367,9 +446,11 @@ ssh_gssapi_userok(char *user) return 0; } if (gssapi_client.mech && gssapi_client.mech->userok) - if ((*gssapi_client.mech->userok)(&gssapi_client, user)) + if ((*gssapi_client.mech->userok)(&gssapi_client, user)) { + gssapi_client.used = 1; + gssapi_client.store.owner = pw; return 1; - else { + } else { /* Destroy delegated credentials if userok fails */ gss_release_buffer(&lmin, &gssapi_client.displayname); gss_release_buffer(&lmin, &gssapi_client.exportedname); @@ -383,14 +464,90 @@ ssh_gssapi_userok(char *user) return (0); } -/* Privileged */ -OM_uint32 -ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) +/* These bits are only used for rekeying. The unpriviledged child is running + * as the user, the monitor is root. + * + * In the child, we want to : + * *) Ask the monitor to store our credentials into the store we specify + * *) If it succeeds, maybe do a PAM update + */ + +/* Stuff for PAM */ + +#ifdef USE_PAM +static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg, + struct pam_response **resp, void *data) { - ctx->major = gss_verify_mic(&ctx->minor, ctx->context, - gssbuf, gssmic, NULL); + return (PAM_CONV_ERR); +} +#endif - return (ctx->major); +void +ssh_gssapi_rekey_creds(void) { + int ok; + int ret; +#ifdef USE_PAM + pam_handle_t *pamh = NULL; + struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL}; + char *envstr; +#endif + + if (gssapi_client.store.filename == NULL && + gssapi_client.store.envval == NULL && + gssapi_client.store.envvar == NULL) + return; + + ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store)); + + if (!ok) + return; + + debug("Rekeyed credentials stored successfully"); + + /* Actually managing to play with the ssh pam stack from here will + * be next to impossible. In any case, we may want different options + * for rekeying. So, use our own :) + */ +#ifdef USE_PAM + if (!use_privsep) { + debug("Not even going to try and do PAM with privsep disabled"); + return; + } + + ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name, + &pamconv, &pamh); + if (ret) + return; + + xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar, + gssapi_client.store.envval); + + ret = pam_putenv(pamh, envstr); + if (!ret) + pam_setcred(pamh, PAM_REINITIALIZE_CRED); + pam_end(pamh, PAM_SUCCESS); +#endif +} + +int +ssh_gssapi_update_creds(ssh_gssapi_ccache *store) { + int ok = 0; + + /* Check we've got credentials to store */ + if (!gssapi_client.updated) + return 0; + + gssapi_client.updated = 0; + + temporarily_use_uid(gssapi_client.store.owner); + if (gssapi_client.mech && gssapi_client.mech->updatecreds) + ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client); + else + debug("No update function for this mechanism"); + + restore_uid(); + + return ok; } #endif diff --git a/kex.c b/kex.c index d371f47c4..913e92392 100644 --- a/kex.c +++ b/kex.c @@ -54,6 +54,10 @@ #include "sshbuf.h" #include "digest.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + #if OPENSSL_VERSION_NUMBER >= 0x00907000L # if defined(HAVE_EVP_SHA256) # define evp_ssh_sha256 EVP_sha256 @@ -109,6 +113,14 @@ static const struct kexalg kexalgs[] = { #endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */ { NULL, -1, -1, -1}, }; +static const struct kexalg kexalg_prefixes[] = { +#ifdef GSSAPI + { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 }, + { KEX_GSS_GRP1_SHA1_ID, KEX_GSS_GRP1_SHA1, 0, SSH_DIGEST_SHA1 }, + { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 }, +#endif + { NULL, -1, -1, -1 }, +}; char * kex_alg_list(char sep) @@ -141,6 +153,10 @@ kex_alg_by_name(const char *name) if (strcmp(k->name, name) == 0) return k; } + for (k = kexalg_prefixes; k->name != NULL; k++) { + if (strncmp(k->name, name, strlen(k->name)) == 0) + return k; + } return NULL; } diff --git a/kex.h b/kex.h index 1c5896605..123ef83c1 100644 --- a/kex.h +++ b/kex.h @@ -92,6 +92,9 @@ enum kex_exchange { KEX_DH_GEX_SHA256, KEX_ECDH_SHA2, KEX_C25519_SHA256, + KEX_GSS_GRP1_SHA1, + KEX_GSS_GRP14_SHA1, + KEX_GSS_GEX_SHA1, KEX_MAX }; @@ -140,6 +143,12 @@ struct kex { u_int flags; int hash_alg; int ec_nid; +#ifdef GSSAPI + int gss_deleg_creds; + int gss_trust_dns; + char *gss_host; + char *gss_client; +#endif char *client_version_string; char *server_version_string; char *failed_choice; @@ -190,6 +199,11 @@ int kexecdh_server(struct ssh *); int kexc25519_client(struct ssh *); int kexc25519_server(struct ssh *); +#ifdef GSSAPI +int kexgss_client(struct ssh *); +int kexgss_server(struct ssh *); +#endif + int kex_dh_hash(const char *, const char *, const u_char *, size_t, const u_char *, size_t, const u_char *, size_t, const BIGNUM *, const BIGNUM *, const BIGNUM *, u_char *, size_t *); diff --git a/kexgssc.c b/kexgssc.c new file mode 100644 index 000000000..a49bac295 --- /dev/null +++ b/kexgssc.c @@ -0,0 +1,336 @@ +/* + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef GSSAPI + +#include "includes.h" + +#include +#include + +#include + +#include "xmalloc.h" +#include "buffer.h" +#include "ssh2.h" +#include "key.h" +#include "cipher.h" +#include "kex.h" +#include "log.h" +#include "packet.h" +#include "dh.h" +#include "digest.h" + +#include "ssh-gss.h" + +int +kexgss_client(struct ssh *ssh) { + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + gss_buffer_desc recv_tok, gssbuf, msg_tok, *token_ptr; + Gssctxt *ctxt; + OM_uint32 maj_status, min_status, ret_flags; + u_int klen, kout, slen = 0, strlen; + DH *dh; + BIGNUM *dh_server_pub = NULL; + BIGNUM *shared_secret = NULL; + BIGNUM *p = NULL; + BIGNUM *g = NULL; + u_char *kbuf; + u_char *serverhostkey = NULL; + u_char *empty = ""; + char *msg; + int type = 0; + int first = 1; + int nbits = 0, min = DH_GRP_MIN, max = DH_GRP_MAX; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t hashlen; + + /* Initialise our GSSAPI world */ + ssh_gssapi_build_ctx(&ctxt); + if (ssh_gssapi_id_kex(ctxt, ssh->kex->name, ssh->kex->kex_type) + == GSS_C_NO_OID) + fatal("Couldn't identify host exchange"); + + if (ssh_gssapi_import_name(ctxt, ssh->kex->gss_host)) + fatal("Couldn't import hostname"); + + if (ssh->kex->gss_client && + ssh_gssapi_client_identity(ctxt, ssh->kex->gss_client)) + fatal("Couldn't acquire client credentials"); + + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + dh = dh_new_group1(); + break; + case KEX_GSS_GRP14_SHA1: + dh = dh_new_group14(); + break; + case KEX_GSS_GEX_SHA1: + debug("Doing group exchange\n"); + nbits = dh_estimate(ssh->kex->we_need * 8); + packet_start(SSH2_MSG_KEXGSS_GROUPREQ); + packet_put_int(min); + packet_put_int(nbits); + packet_put_int(max); + + packet_send(); + + packet_read_expect(SSH2_MSG_KEXGSS_GROUP); + + if ((p = BN_new()) == NULL) + fatal("BN_new() failed"); + packet_get_bignum2(p); + if ((g = BN_new()) == NULL) + fatal("BN_new() failed"); + packet_get_bignum2(g); + packet_check_eom(); + + if (BN_num_bits(p) < min || BN_num_bits(p) > max) + fatal("GSSGRP_GEX group out of range: %d !< %d !< %d", + min, BN_num_bits(p), max); + + dh = dh_new_group(g, p); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + /* Step 1 - e is dh->pub_key */ + dh_gen_key(dh, ssh->kex->we_need * 8); + + /* This is f, we initialise it now to make life easier */ + dh_server_pub = BN_new(); + if (dh_server_pub == NULL) + fatal("dh_server_pub == NULL"); + + token_ptr = GSS_C_NO_BUFFER; + + do { + debug("Calling gss_init_sec_context"); + + maj_status = ssh_gssapi_init_ctx(ctxt, + ssh->kex->gss_deleg_creds, token_ptr, &send_tok, + &ret_flags); + + if (GSS_ERROR(maj_status)) { + if (send_tok.length != 0) { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, + send_tok.length); + } + fatal("gss_init_context failed"); + } + + /* If we've got an old receive buffer get rid of it */ + if (token_ptr != GSS_C_NO_BUFFER) + free(recv_tok.value); + + if (maj_status == GSS_S_COMPLETE) { + /* If mutual state flag is not true, kex fails */ + if (!(ret_flags & GSS_C_MUTUAL_FLAG)) + fatal("Mutual authentication failed"); + + /* If integ avail flag is not true kex fails */ + if (!(ret_flags & GSS_C_INTEG_FLAG)) + fatal("Integrity check failed"); + } + + /* + * If we have data to send, then the last message that we + * received cannot have been a 'complete'. + */ + if (send_tok.length != 0) { + if (first) { + packet_start(SSH2_MSG_KEXGSS_INIT); + packet_put_string(send_tok.value, + send_tok.length); + packet_put_bignum2(dh->pub_key); + first = 0; + } else { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, + send_tok.length); + } + packet_send(); + gss_release_buffer(&min_status, &send_tok); + + /* If we've sent them data, they should reply */ + do { + type = packet_read(); + if (type == SSH2_MSG_KEXGSS_HOSTKEY) { + debug("Received KEXGSS_HOSTKEY"); + if (serverhostkey) + fatal("Server host key received more than once"); + serverhostkey = + packet_get_string(&slen); + } + } while (type == SSH2_MSG_KEXGSS_HOSTKEY); + + switch (type) { + case SSH2_MSG_KEXGSS_CONTINUE: + debug("Received GSSAPI_CONTINUE"); + if (maj_status == GSS_S_COMPLETE) + fatal("GSSAPI Continue received from server when complete"); + recv_tok.value = packet_get_string(&strlen); + recv_tok.length = strlen; + break; + case SSH2_MSG_KEXGSS_COMPLETE: + debug("Received GSSAPI_COMPLETE"); + packet_get_bignum2(dh_server_pub); + msg_tok.value = packet_get_string(&strlen); + msg_tok.length = strlen; + + /* Is there a token included? */ + if (packet_get_char()) { + recv_tok.value= + packet_get_string(&strlen); + recv_tok.length = strlen; + /* If we're already complete - protocol error */ + if (maj_status == GSS_S_COMPLETE) + packet_disconnect("Protocol error: received token when complete"); + } else { + /* No token included */ + if (maj_status != GSS_S_COMPLETE) + packet_disconnect("Protocol error: did not receive final token"); + } + break; + case SSH2_MSG_KEXGSS_ERROR: + debug("Received Error"); + maj_status = packet_get_int(); + min_status = packet_get_int(); + msg = packet_get_string(NULL); + (void) packet_get_string_ptr(NULL); + fatal("GSSAPI Error: \n%.400s",msg); + default: + packet_disconnect("Protocol error: didn't expect packet type %d", + type); + } + token_ptr = &recv_tok; + } else { + /* No data, and not complete */ + if (maj_status != GSS_S_COMPLETE) + fatal("Not complete, and no token output"); + } + } while (maj_status & GSS_S_CONTINUE_NEEDED); + + /* + * We _must_ have received a COMPLETE message in reply from the + * server, which will have set dh_server_pub and msg_tok + */ + + if (type != SSH2_MSG_KEXGSS_COMPLETE) + fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it"); + + /* Check f in range [1, p-1] */ + if (!dh_pub_is_valid(dh, dh_server_pub)) + packet_disconnect("bad server public DH value"); + + /* compute K=f^x mod p */ + klen = DH_size(dh); + kbuf = xmalloc(klen); + kout = DH_compute_key(kbuf, dh_server_pub, dh); + if (kout < 0) + fatal("DH_compute_key: failed"); + + shared_secret = BN_new(); + if (shared_secret == NULL) + fatal("kexgss_client: BN_new failed"); + + if (BN_bin2bn(kbuf, kout, shared_secret) == NULL) + fatal("kexdh_client: BN_bin2bn failed"); + + memset(kbuf, 0, klen); + free(kbuf); + + hashlen = sizeof(hash); + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + case KEX_GSS_GRP14_SHA1: + kex_dh_hash( ssh->kex->client_version_string, + ssh->kex->server_version_string, + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + (serverhostkey ? serverhostkey : empty), slen, + dh->pub_key, /* e */ + dh_server_pub, /* f */ + shared_secret, /* K */ + hash, &hashlen + ); + break; + case KEX_GSS_GEX_SHA1: + kexgex_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, + ssh->kex->server_version_string, + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + (serverhostkey ? serverhostkey : empty), slen, + min, nbits, max, + dh->p, dh->g, + dh->pub_key, + dh_server_pub, + shared_secret, + hash, &hashlen + ); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + gssbuf.value = hash; + gssbuf.length = hashlen; + + /* Verify that the hash matches the MIC we just got. */ + if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok))) + packet_disconnect("Hash's MIC didn't verify"); + + free(msg_tok.value); + + DH_free(dh); + free(serverhostkey); + BN_clear_free(dh_server_pub); + + /* save session id */ + if (ssh->kex->session_id == NULL) { + ssh->kex->session_id_len = hashlen; + ssh->kex->session_id = xmalloc(ssh->kex->session_id_len); + memcpy(ssh->kex->session_id, hash, ssh->kex->session_id_len); + } + + if (ssh->kex->gss_deleg_creds) + ssh_gssapi_credentials_updated(ctxt); + + if (gss_kex_context == NULL) + gss_kex_context = ctxt; + else + ssh_gssapi_delete_ctx(&ctxt); + + kex_derive_keys_bn(ssh, hash, hashlen, shared_secret); + BN_clear_free(shared_secret); + return kex_send_newkeys(ssh); +} + +#endif /* GSSAPI */ diff --git a/kexgsss.c b/kexgsss.c new file mode 100644 index 000000000..0847469af --- /dev/null +++ b/kexgsss.c @@ -0,0 +1,295 @@ +/* + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef GSSAPI + +#include + +#include +#include + +#include "xmalloc.h" +#include "buffer.h" +#include "ssh2.h" +#include "key.h" +#include "cipher.h" +#include "kex.h" +#include "log.h" +#include "packet.h" +#include "dh.h" +#include "ssh-gss.h" +#include "monitor_wrap.h" +#include "misc.h" +#include "servconf.h" +#include "digest.h" + +extern ServerOptions options; + +int +kexgss_server(struct ssh *ssh) +{ + OM_uint32 maj_status, min_status; + + /* + * Some GSSAPI implementations use the input value of ret_flags (an + * output variable) as a means of triggering mechanism specific + * features. Initializing it to zero avoids inadvertently + * activating this non-standard behaviour. + */ + + OM_uint32 ret_flags = 0; + gss_buffer_desc gssbuf, recv_tok, msg_tok; + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + Gssctxt *ctxt = NULL; + u_int slen, klen, kout; + u_char *kbuf; + DH *dh; + int min = -1, max = -1, nbits = -1; + BIGNUM *shared_secret = NULL; + BIGNUM *dh_client_pub = NULL; + int type = 0; + gss_OID oid; + char *mechs; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t hashlen; + + /* Initialise GSSAPI */ + + /* If we're rekeying, privsep means that some of the private structures + * in the GSSAPI code are no longer available. This kludges them back + * into life + */ + if (!ssh_gssapi_oid_table_ok()) { + mechs = ssh_gssapi_server_mechanisms(); + free(mechs); + } + + debug2("%s: Identifying %s", __func__, ssh->kex->name); + oid = ssh_gssapi_id_kex(NULL, ssh->kex->name, ssh->kex->kex_type); + if (oid == GSS_C_NO_OID) + fatal("Unknown gssapi mechanism"); + + debug2("%s: Acquiring credentials", __func__); + + if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid)))) + fatal("Unable to acquire credentials for the server"); + + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + dh = dh_new_group1(); + break; + case KEX_GSS_GRP14_SHA1: + dh = dh_new_group14(); + break; + case KEX_GSS_GEX_SHA1: + debug("Doing group exchange"); + packet_read_expect(SSH2_MSG_KEXGSS_GROUPREQ); + min = packet_get_int(); + nbits = packet_get_int(); + max = packet_get_int(); + min = MAX(DH_GRP_MIN, min); + max = MIN(DH_GRP_MAX, max); + packet_check_eom(); + if (max < min || nbits < min || max < nbits) + fatal("GSS_GEX, bad parameters: %d !< %d !< %d", + min, nbits, max); + dh = PRIVSEP(choose_dh(min, nbits, max)); + if (dh == NULL) + packet_disconnect("Protocol error: no matching group found"); + + packet_start(SSH2_MSG_KEXGSS_GROUP); + packet_put_bignum2(dh->p); + packet_put_bignum2(dh->g); + packet_send(); + + packet_write_wait(); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + dh_gen_key(dh, ssh->kex->we_need * 8); + + do { + debug("Wait SSH2_MSG_GSSAPI_INIT"); + type = packet_read(); + switch(type) { + case SSH2_MSG_KEXGSS_INIT: + if (dh_client_pub != NULL) + fatal("Received KEXGSS_INIT after initialising"); + recv_tok.value = packet_get_string(&slen); + recv_tok.length = slen; + + if ((dh_client_pub = BN_new()) == NULL) + fatal("dh_client_pub == NULL"); + + packet_get_bignum2(dh_client_pub); + + /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */ + break; + case SSH2_MSG_KEXGSS_CONTINUE: + recv_tok.value = packet_get_string(&slen); + recv_tok.length = slen; + break; + default: + packet_disconnect( + "Protocol error: didn't expect packet type %d", + type); + } + + maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok, + &send_tok, &ret_flags)); + + free(recv_tok.value); + + if (maj_status != GSS_S_COMPLETE && send_tok.length == 0) + fatal("Zero length token output when incomplete"); + + if (dh_client_pub == NULL) + fatal("No client public key"); + + if (maj_status & GSS_S_CONTINUE_NEEDED) { + debug("Sending GSSAPI_CONTINUE"); + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + gss_release_buffer(&min_status, &send_tok); + } + } while (maj_status & GSS_S_CONTINUE_NEEDED); + + if (GSS_ERROR(maj_status)) { + if (send_tok.length > 0) { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + } + fatal("accept_ctx died"); + } + + if (!(ret_flags & GSS_C_MUTUAL_FLAG)) + fatal("Mutual Authentication flag wasn't set"); + + if (!(ret_flags & GSS_C_INTEG_FLAG)) + fatal("Integrity flag wasn't set"); + + if (!dh_pub_is_valid(dh, dh_client_pub)) + packet_disconnect("bad client public DH value"); + + klen = DH_size(dh); + kbuf = xmalloc(klen); + kout = DH_compute_key(kbuf, dh_client_pub, dh); + if (kout < 0) + fatal("DH_compute_key: failed"); + + shared_secret = BN_new(); + if (shared_secret == NULL) + fatal("kexgss_server: BN_new failed"); + + if (BN_bin2bn(kbuf, kout, shared_secret) == NULL) + fatal("kexgss_server: BN_bin2bn failed"); + + memset(kbuf, 0, klen); + free(kbuf); + + hashlen = sizeof(hash); + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + case KEX_GSS_GRP14_SHA1: + kex_dh_hash( + ssh->kex->client_version_string, ssh->kex->server_version_string, + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + NULL, 0, /* Change this if we start sending host keys */ + dh_client_pub, dh->pub_key, shared_secret, + hash, &hashlen + ); + break; + case KEX_GSS_GEX_SHA1: + kexgex_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, ssh->kex->server_version_string, + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + NULL, 0, + min, nbits, max, + dh->p, dh->g, + dh_client_pub, + dh->pub_key, + shared_secret, + hash, &hashlen + ); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + BN_clear_free(dh_client_pub); + + if (ssh->kex->session_id == NULL) { + ssh->kex->session_id_len = hashlen; + ssh->kex->session_id = xmalloc(ssh->kex->session_id_len); + memcpy(ssh->kex->session_id, hash, ssh->kex->session_id_len); + } + + gssbuf.value = hash; + gssbuf.length = hashlen; + + if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt,&gssbuf,&msg_tok)))) + fatal("Couldn't get MIC"); + + packet_start(SSH2_MSG_KEXGSS_COMPLETE); + packet_put_bignum2(dh->pub_key); + packet_put_string(msg_tok.value,msg_tok.length); + + if (send_tok.length != 0) { + packet_put_char(1); /* true */ + packet_put_string(send_tok.value, send_tok.length); + } else { + packet_put_char(0); /* false */ + } + packet_send(); + + gss_release_buffer(&min_status, &send_tok); + gss_release_buffer(&min_status, &msg_tok); + + if (gss_kex_context == NULL) + gss_kex_context = ctxt; + else + ssh_gssapi_delete_ctx(&ctxt); + + DH_free(dh); + + kex_derive_keys_bn(ssh, hash, hashlen, shared_secret); + BN_clear_free(shared_secret); + kex_send_newkeys(ssh); + + /* If this was a rekey, then save out any delegated credentials we + * just exchanged. */ + if (options.gss_store_rekey) + ssh_gssapi_rekey_creds(); + return 0; +} +#endif /* GSSAPI */ diff --git a/monitor.c b/monitor.c index ac7dd3099..6c8202325 100644 --- a/monitor.c +++ b/monitor.c @@ -156,6 +156,8 @@ int mm_answer_gss_setup_ctx(int, Buffer *); int mm_answer_gss_accept_ctx(int, Buffer *); int mm_answer_gss_userok(int, Buffer *); int mm_answer_gss_checkmic(int, Buffer *); +int mm_answer_gss_sign(int, Buffer *); +int mm_answer_gss_updatecreds(int, Buffer *); #endif #ifdef SSH_AUDIT_EVENTS @@ -233,11 +235,18 @@ struct mon_table mon_dispatch_proto20[] = { {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, + {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign}, #endif {0, 0, NULL} }; struct mon_table mon_dispatch_postauth20[] = { +#ifdef GSSAPI + {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx}, + {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx}, + {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign}, + {MONITOR_REQ_GSSUPCREDS, 0, mm_answer_gss_updatecreds}, +#endif #ifdef WITH_OPENSSL {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, #endif @@ -352,6 +361,10 @@ monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) /* Permit requests for moduli and signatures */ monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); +#ifdef GSSAPI + /* and for the GSSAPI key exchange */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1); +#endif } else { mon_dispatch = mon_dispatch_proto15; @@ -460,6 +473,10 @@ monitor_child_postauth(struct monitor *pmonitor) monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); +#ifdef GSSAPI + /* and for the GSSAPI key exchange */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1); +#endif } else { mon_dispatch = mon_dispatch_postauth15; monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); @@ -1861,6 +1878,13 @@ monitor_apply_keystate(struct monitor *pmonitor) # endif #endif /* WITH_OPENSSL */ kex->kex[KEX_C25519_SHA256] = kexc25519_server; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server; + } +#endif kex->load_host_public_key=&get_hostkey_public_by_type; kex->load_host_private_key=&get_hostkey_private_by_type; kex->host_key_index=&get_hostkey_index; @@ -1960,6 +1984,9 @@ mm_answer_gss_setup_ctx(int sock, Buffer *m) OM_uint32 major; u_int len; + if (!options.gss_authentication && !options.gss_keyex) + fatal("In GSSAPI monitor when GSSAPI is disabled"); + goid.elements = buffer_get_string(m, &len); goid.length = len; @@ -1987,6 +2014,9 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m) OM_uint32 flags = 0; /* GSI needs this */ u_int len; + if (!options.gss_authentication && !options.gss_keyex) + fatal("In GSSAPI monitor when GSSAPI is disabled"); + in.value = buffer_get_string(m, &len); in.length = len; major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); @@ -2004,6 +2034,7 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m) monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN, 1); } return (0); } @@ -2015,6 +2046,9 @@ mm_answer_gss_checkmic(int sock, Buffer *m) OM_uint32 ret; u_int len; + if (!options.gss_authentication && !options.gss_keyex) + fatal("In GSSAPI monitor when GSSAPI is disabled"); + gssbuf.value = buffer_get_string(m, &len); gssbuf.length = len; mic.value = buffer_get_string(m, &len); @@ -2041,7 +2075,11 @@ mm_answer_gss_userok(int sock, Buffer *m) { int authenticated; - authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); + if (!options.gss_authentication && !options.gss_keyex) + fatal("In GSSAPI monitor when GSSAPI is disabled"); + + authenticated = authctxt->valid && + ssh_gssapi_userok(authctxt->user, authctxt->pw); buffer_clear(m); buffer_put_int(m, authenticated); @@ -2054,5 +2092,73 @@ mm_answer_gss_userok(int sock, Buffer *m) /* Monitor loop will terminate if authenticated */ return (authenticated); } + +int +mm_answer_gss_sign(int socket, Buffer *m) +{ + gss_buffer_desc data; + gss_buffer_desc hash = GSS_C_EMPTY_BUFFER; + OM_uint32 major, minor; + u_int len; + + if (!options.gss_authentication && !options.gss_keyex) + fatal("In GSSAPI monitor when GSSAPI is disabled"); + + data.value = buffer_get_string(m, &len); + data.length = len; + if (data.length != 20) + fatal("%s: data length incorrect: %d", __func__, + (int) data.length); + + /* Save the session ID on the first time around */ + if (session_id2_len == 0) { + session_id2_len = data.length; + session_id2 = xmalloc(session_id2_len); + memcpy(session_id2, data.value, session_id2_len); + } + major = ssh_gssapi_sign(gsscontext, &data, &hash); + + free(data.value); + + buffer_clear(m); + buffer_put_int(m, major); + buffer_put_string(m, hash.value, hash.length); + + mm_request_send(socket, MONITOR_ANS_GSSSIGN, m); + + gss_release_buffer(&minor, &hash); + + /* Turn on getpwnam permissions */ + monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); + + /* And credential updating, for when rekeying */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSUPCREDS, 1); + + return (0); +} + +int +mm_answer_gss_updatecreds(int socket, Buffer *m) { + ssh_gssapi_ccache store; + int ok; + + store.filename = buffer_get_string(m, NULL); + store.envvar = buffer_get_string(m, NULL); + store.envval = buffer_get_string(m, NULL); + + ok = ssh_gssapi_update_creds(&store); + + free(store.filename); + free(store.envvar); + free(store.envval); + + buffer_clear(m); + buffer_put_int(m, ok); + + mm_request_send(socket, MONITOR_ANS_GSSUPCREDS, m); + + return(0); +} + #endif /* GSSAPI */ diff --git a/monitor.h b/monitor.h index 93b8b66dd..bc50ade1f 100644 --- a/monitor.h +++ b/monitor.h @@ -65,6 +65,9 @@ enum monitor_reqtype { MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111, MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113, + MONITOR_REQ_GSSSIGN = 150, MONITOR_ANS_GSSSIGN = 151, + MONITOR_REQ_GSSUPCREDS = 152, MONITOR_ANS_GSSUPCREDS = 153, + }; struct mm_master; diff --git a/monitor_wrap.c b/monitor_wrap.c index c5db6df48..74fbd2ef3 100644 --- a/monitor_wrap.c +++ b/monitor_wrap.c @@ -1068,7 +1068,7 @@ mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) } int -mm_ssh_gssapi_userok(char *user) +mm_ssh_gssapi_userok(char *user, struct passwd *pw) { Buffer m; int authenticated = 0; @@ -1085,5 +1085,50 @@ mm_ssh_gssapi_userok(char *user) debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); return (authenticated); } + +OM_uint32 +mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash) +{ + Buffer m; + OM_uint32 major; + u_int len; + + buffer_init(&m); + buffer_put_string(&m, data->value, data->length); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, &m); + + major = buffer_get_int(&m); + hash->value = buffer_get_string(&m, &len); + hash->length = len; + + buffer_free(&m); + + return(major); +} + +int +mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store) +{ + Buffer m; + int ok; + + buffer_init(&m); + + buffer_put_cstring(&m, store->filename ? store->filename : ""); + buffer_put_cstring(&m, store->envvar ? store->envvar : ""); + buffer_put_cstring(&m, store->envval ? store->envval : ""); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, &m); + + ok = buffer_get_int(&m); + + buffer_free(&m); + + return (ok); +} + #endif /* GSSAPI */ diff --git a/monitor_wrap.h b/monitor_wrap.h index eb820aeea..403f8d00c 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -58,8 +58,10 @@ BIGNUM *mm_auth_rsa_generate_challenge(Key *); OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID); OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *, gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *); -int mm_ssh_gssapi_userok(char *user); +int mm_ssh_gssapi_userok(char *user, struct passwd *); OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t); +OM_uint32 mm_ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t); +int mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *); #endif #ifdef USE_PAM diff --git a/readconf.c b/readconf.c index 69d4553af..d2a3d4b1a 100644 --- a/readconf.c +++ b/readconf.c @@ -148,6 +148,8 @@ typedef enum { oClearAllForwardings, oNoHostAuthenticationForLocalhost, oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout, oAddressFamily, oGssAuthentication, oGssDelegateCreds, + oGssTrustDns, oGssKeyEx, oGssClientIdentity, oGssRenewalRekey, + oGssServerIdentity, oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly, oSendEnv, oControlPath, oControlMaster, oControlPersist, oHashKnownHosts, @@ -193,10 +195,19 @@ static struct { { "afstokenpassing", oUnsupported }, #if defined(GSSAPI) { "gssapiauthentication", oGssAuthentication }, + { "gssapikeyexchange", oGssKeyEx }, { "gssapidelegatecredentials", oGssDelegateCreds }, + { "gssapitrustdns", oGssTrustDns }, + { "gssapiclientidentity", oGssClientIdentity }, + { "gssapiserveridentity", oGssServerIdentity }, + { "gssapirenewalforcesrekey", oGssRenewalRekey }, #else { "gssapiauthentication", oUnsupported }, + { "gssapikeyexchange", oUnsupported }, { "gssapidelegatecredentials", oUnsupported }, + { "gssapitrustdns", oUnsupported }, + { "gssapiclientidentity", oUnsupported }, + { "gssapirenewalforcesrekey", oUnsupported }, #endif { "fallbacktorsh", oDeprecated }, { "usersh", oDeprecated }, @@ -926,10 +937,30 @@ parse_time: intptr = &options->gss_authentication; goto parse_flag; + case oGssKeyEx: + intptr = &options->gss_keyex; + goto parse_flag; + case oGssDelegateCreds: intptr = &options->gss_deleg_creds; goto parse_flag; + case oGssTrustDns: + intptr = &options->gss_trust_dns; + goto parse_flag; + + case oGssClientIdentity: + charptr = &options->gss_client_identity; + goto parse_string; + + case oGssServerIdentity: + charptr = &options->gss_server_identity; + goto parse_string; + + case oGssRenewalRekey: + intptr = &options->gss_renewal_rekey; + goto parse_flag; + case oBatchMode: intptr = &options->batch_mode; goto parse_flag; @@ -1648,7 +1679,12 @@ initialize_options(Options * options) options->pubkey_authentication = -1; options->challenge_response_authentication = -1; options->gss_authentication = -1; + options->gss_keyex = -1; options->gss_deleg_creds = -1; + options->gss_trust_dns = -1; + options->gss_renewal_rekey = -1; + options->gss_client_identity = NULL; + options->gss_server_identity = NULL; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->kbd_interactive_devices = NULL; @@ -1777,8 +1813,14 @@ fill_default_options(Options * options) options->challenge_response_authentication = 1; if (options->gss_authentication == -1) options->gss_authentication = 0; + if (options->gss_keyex == -1) + options->gss_keyex = 0; if (options->gss_deleg_creds == -1) options->gss_deleg_creds = 0; + if (options->gss_trust_dns == -1) + options->gss_trust_dns = 0; + if (options->gss_renewal_rekey == -1) + options->gss_renewal_rekey = 0; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) diff --git a/readconf.h b/readconf.h index c84d068bd..37a055521 100644 --- a/readconf.h +++ b/readconf.h @@ -45,7 +45,12 @@ typedef struct { int challenge_response_authentication; /* Try S/Key or TIS, authentication. */ int gss_authentication; /* Try GSS authentication */ + int gss_keyex; /* Try GSS key exchange */ int gss_deleg_creds; /* Delegate GSS credentials */ + int gss_trust_dns; /* Trust DNS for GSS canonicalization */ + int gss_renewal_rekey; /* Credential renewal forces rekey */ + char *gss_client_identity; /* Principal to initiate GSSAPI with */ + char *gss_server_identity; /* GSSAPI target principal */ int password_authentication; /* Try password * authentication. */ int kbd_interactive_authentication; /* Try keyboard-interactive auth. */ diff --git a/servconf.c b/servconf.c index b19d30e18..b8af6dda7 100644 --- a/servconf.c +++ b/servconf.c @@ -117,8 +117,10 @@ initialize_server_options(ServerOptions *options) options->kerberos_ticket_cleanup = -1; options->kerberos_get_afs_token = -1; options->gss_authentication=-1; + options->gss_keyex = -1; options->gss_cleanup_creds = -1; options->gss_strict_acceptor = -1; + options->gss_store_rekey = -1; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->challenge_response_authentication = -1; @@ -287,10 +289,14 @@ fill_default_server_options(ServerOptions *options) options->kerberos_get_afs_token = 0; if (options->gss_authentication == -1) options->gss_authentication = 0; + if (options->gss_keyex == -1) + options->gss_keyex = 0; if (options->gss_cleanup_creds == -1) options->gss_cleanup_creds = 1; if (options->gss_strict_acceptor == -1) - options->gss_strict_acceptor = 0; + options->gss_strict_acceptor = 1; + if (options->gss_store_rekey == -1) + options->gss_store_rekey = 0; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) @@ -419,6 +425,7 @@ typedef enum { sHostKeyAlgorithms, sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile, sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor, + sGssKeyEx, sGssStoreRekey, sAcceptEnv, sPermitTunnel, sMatch, sPermitOpen, sForceCommand, sChrootDirectory, sUsePrivilegeSeparation, sAllowAgentForwarding, @@ -492,12 +499,20 @@ static struct { #ifdef GSSAPI { "gssapiauthentication", sGssAuthentication, SSHCFG_ALL }, { "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL }, + { "gssapicleanupcreds", sGssCleanupCreds, SSHCFG_GLOBAL }, { "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL }, + { "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL }, + { "gssapistorecredentialsonrekey", sGssStoreRekey, SSHCFG_GLOBAL }, #else { "gssapiauthentication", sUnsupported, SSHCFG_ALL }, { "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL }, + { "gssapicleanupcreds", sUnsupported, SSHCFG_GLOBAL }, { "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL }, + { "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL }, + { "gssapistorecredentialsonrekey", sUnsupported, SSHCFG_GLOBAL }, #endif + { "gssusesessionccache", sUnsupported, SSHCFG_GLOBAL }, + { "gssapiusesessioncredcache", sUnsupported, SSHCFG_GLOBAL }, { "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL }, { "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL }, { "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, @@ -1242,6 +1257,10 @@ process_server_config_line(ServerOptions *options, char *line, intptr = &options->gss_authentication; goto parse_flag; + case sGssKeyEx: + intptr = &options->gss_keyex; + goto parse_flag; + case sGssCleanupCreds: intptr = &options->gss_cleanup_creds; goto parse_flag; @@ -1250,6 +1269,10 @@ process_server_config_line(ServerOptions *options, char *line, intptr = &options->gss_strict_acceptor; goto parse_flag; + case sGssStoreRekey: + intptr = &options->gss_store_rekey; + goto parse_flag; + case sPasswordAuthentication: intptr = &options->password_authentication; goto parse_flag; @@ -2265,7 +2288,10 @@ dump_config(ServerOptions *o) #endif #ifdef GSSAPI dump_cfg_fmtint(sGssAuthentication, o->gss_authentication); + dump_cfg_fmtint(sGssKeyEx, o->gss_keyex); dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds); + dump_cfg_fmtint(sGssStrictAcceptor, o->gss_strict_acceptor); + dump_cfg_fmtint(sGssStoreRekey, o->gss_store_rekey); #endif dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication); dump_cfg_fmtint(sKbdInteractiveAuthentication, diff --git a/servconf.h b/servconf.h index f4137af7d..778ba1742 100644 --- a/servconf.h +++ b/servconf.h @@ -118,8 +118,10 @@ typedef struct { int kerberos_get_afs_token; /* If true, try to get AFS token if * authenticated with Kerberos. */ int gss_authentication; /* If true, permit GSSAPI authentication */ + int gss_keyex; /* If true, permit GSSAPI key exchange */ int gss_cleanup_creds; /* If true, destroy cred cache on logout */ int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ + int gss_store_rekey; int password_authentication; /* If true, permit password * authentication. */ int kbd_interactive_authentication; /* If true, permit */ diff --git a/ssh-gss.h b/ssh-gss.h index a99d7f08b..914701bcf 100644 --- a/ssh-gss.h +++ b/ssh-gss.h @@ -1,6 +1,6 @@ /* $OpenBSD: ssh-gss.h,v 1.11 2014/02/26 20:28:44 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -61,10 +61,22 @@ #define SSH_GSS_OIDTYPE 0x06 +#define SSH2_MSG_KEXGSS_INIT 30 +#define SSH2_MSG_KEXGSS_CONTINUE 31 +#define SSH2_MSG_KEXGSS_COMPLETE 32 +#define SSH2_MSG_KEXGSS_HOSTKEY 33 +#define SSH2_MSG_KEXGSS_ERROR 34 +#define SSH2_MSG_KEXGSS_GROUPREQ 40 +#define SSH2_MSG_KEXGSS_GROUP 41 +#define KEX_GSS_GRP1_SHA1_ID "gss-group1-sha1-" +#define KEX_GSS_GRP14_SHA1_ID "gss-group14-sha1-" +#define KEX_GSS_GEX_SHA1_ID "gss-gex-sha1-" + typedef struct { char *filename; char *envvar; char *envval; + struct passwd *owner; void *data; } ssh_gssapi_ccache; @@ -72,8 +84,11 @@ typedef struct { gss_buffer_desc displayname; gss_buffer_desc exportedname; gss_cred_id_t creds; + gss_name_t name; struct ssh_gssapi_mech_struct *mech; ssh_gssapi_ccache store; + int used; + int updated; } ssh_gssapi_client; typedef struct ssh_gssapi_mech_struct { @@ -84,6 +99,7 @@ typedef struct ssh_gssapi_mech_struct { int (*userok) (ssh_gssapi_client *, char *); int (*localname) (ssh_gssapi_client *, char **); void (*storecreds) (ssh_gssapi_client *); + int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *); } ssh_gssapi_mech; typedef struct { @@ -94,10 +110,11 @@ typedef struct { gss_OID oid; /* client */ gss_cred_id_t creds; /* server */ gss_name_t client; /* server */ - gss_cred_id_t client_creds; /* server */ + gss_cred_id_t client_creds; /* both */ } Gssctxt; extern ssh_gssapi_mech *supported_mechs[]; +extern Gssctxt *gss_kex_context; int ssh_gssapi_check_oid(Gssctxt *, void *, size_t); void ssh_gssapi_set_oid_data(Gssctxt *, void *, size_t); @@ -119,16 +136,32 @@ void ssh_gssapi_build_ctx(Gssctxt **); void ssh_gssapi_delete_ctx(Gssctxt **); OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t); void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *); -int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *); +int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *, const char *); +OM_uint32 ssh_gssapi_client_identity(Gssctxt *, const char *); +int ssh_gssapi_credentials_updated(Gssctxt *); /* In the server */ +typedef int ssh_gssapi_check_fn(Gssctxt **, gss_OID, const char *, + const char *); +char *ssh_gssapi_client_mechanisms(const char *, const char *); +char *ssh_gssapi_kex_mechs(gss_OID_set, ssh_gssapi_check_fn *, const char *, + const char *); +gss_OID ssh_gssapi_id_kex(Gssctxt *, char *, int); +int ssh_gssapi_server_check_mech(Gssctxt **,gss_OID, const char *, + const char *); OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID); -int ssh_gssapi_userok(char *name); +int ssh_gssapi_userok(char *name, struct passwd *); OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t); void ssh_gssapi_do_child(char ***, u_int *); void ssh_gssapi_cleanup_creds(void); void ssh_gssapi_storecreds(void); +char *ssh_gssapi_server_mechanisms(void); +int ssh_gssapi_oid_table_ok(void); + +int ssh_gssapi_update_creds(ssh_gssapi_ccache *store); +void ssh_gssapi_rekey_creds(void); + #endif /* GSSAPI */ #endif /* _SSH_GSS_H */ diff --git a/ssh_config b/ssh_config index 90fb63f0b..4e879cd20 100644 --- a/ssh_config +++ b/ssh_config @@ -26,6 +26,8 @@ # HostbasedAuthentication no # GSSAPIAuthentication no # GSSAPIDelegateCredentials no +# GSSAPIKeyExchange no +# GSSAPITrustDNS no # BatchMode no # CheckHostIP yes # AddressFamily any diff --git a/ssh_config.5 b/ssh_config.5 index caf13a62d..9060d5be2 100644 --- a/ssh_config.5 +++ b/ssh_config.5 @@ -826,10 +826,42 @@ The default is Specifies whether user authentication based on GSSAPI is allowed. The default is .Dq no . +.It Cm GSSAPIKeyExchange +Specifies whether key exchange based on GSSAPI may be used. When using +GSSAPI key exchange the server need not have a host key. +The default is +.Dq no . +.It Cm GSSAPIClientIdentity +If set, specifies the GSSAPI client identity that ssh should use when +connecting to the server. The default is unset, which means that the default +identity will be used. +.It Cm GSSAPIServerIdentity +If set, specifies the GSSAPI server identity that ssh should expect when +connecting to the server. The default is unset, which means that the +expected GSSAPI server identity will be determined from the target +hostname. .It Cm GSSAPIDelegateCredentials Forward (delegate) credentials to the server. The default is .Dq no . +.It Cm GSSAPIRenewalForcesRekey +If set to +.Dq yes +then renewal of the client's GSSAPI credentials will force the rekeying of the +ssh connection. With a compatible server, this can delegate the renewed +credentials to a session on the server. +The default is +.Dq no . +.It Cm GSSAPITrustDns +Set to +.Dq yes +to indicate that the DNS is trusted to securely canonicalize +the name of the host being connected to. If +.Dq no , +the hostname entered on the +command line will be passed untouched to the GSSAPI library. +The default is +.Dq no . .It Cm HashKnownHosts Indicates that .Xr ssh 1 diff --git a/sshconnect2.c b/sshconnect2.c index f79c96beb..b452eae24 100644 --- a/sshconnect2.c +++ b/sshconnect2.c @@ -161,6 +161,11 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) struct kex *kex; int r; +#ifdef GSSAPI + char *orig = NULL, *gss = NULL; + char *gss_host = NULL; +#endif + xxx_host = host; xxx_hostaddr = hostaddr; @@ -195,6 +200,33 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) order_hostkeyalgs(host, hostaddr, port)); } +#ifdef GSSAPI + if (options.gss_keyex) { + /* Add the GSSAPI mechanisms currently supported on this + * client to the key exchange algorithm proposal */ + orig = myproposal[PROPOSAL_KEX_ALGS]; + + if (options.gss_trust_dns) + gss_host = (char *)get_canonical_hostname(1); + else + gss_host = host; + + gss = ssh_gssapi_client_mechanisms(gss_host, options.gss_client_identity); + if (gss) { + debug("Offering GSSAPI proposal: %s", gss); + xasprintf(&myproposal[PROPOSAL_KEX_ALGS], + "%s,%s", gss, orig); + + /* If we've got GSSAPI algorithms, then we also + * support the 'null' hostkey, as a last resort */ + orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; + xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], + "%s,null", orig); + free(gss); + } + } +#endif + if (options.rekey_limit || options.rekey_interval) packet_set_rekey_limits((u_int32_t)options.rekey_limit, (time_t)options.rekey_interval); @@ -213,10 +245,30 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) # endif #endif kex->kex[KEX_C25519_SHA256] = kexc25519_client; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; + } +#endif kex->client_version_string=client_version_string; kex->server_version_string=server_version_string; kex->verify_host_key=&verify_host_key_callback; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->gss_deleg_creds = options.gss_deleg_creds; + kex->gss_trust_dns = options.gss_trust_dns; + kex->gss_client = options.gss_client_identity; + if (options.gss_server_identity) { + kex->gss_host = options.gss_server_identity; + } else { + kex->gss_host = gss_host; + } + } +#endif + dispatch_run(DISPATCH_BLOCK, &kex->done, active_state); /* remove ext-info from the KEX proposals for rekeying */ @@ -311,6 +363,7 @@ int input_gssapi_token(int type, u_int32_t, void *); int input_gssapi_hash(int type, u_int32_t, void *); int input_gssapi_error(int, u_int32_t, void *); int input_gssapi_errtok(int, u_int32_t, void *); +int userauth_gsskeyex(Authctxt *authctxt); #endif void userauth(Authctxt *, char *); @@ -326,6 +379,11 @@ static char *authmethods_get(void); Authmethod authmethods[] = { #ifdef GSSAPI + {"gssapi-keyex", + userauth_gsskeyex, + NULL, + &options.gss_authentication, + NULL}, {"gssapi-with-mic", userauth_gssapi, NULL, @@ -656,19 +714,31 @@ userauth_gssapi(Authctxt *authctxt) static u_int mech = 0; OM_uint32 min; int ok = 0; + const char *gss_host; + + if (options.gss_server_identity) + gss_host = options.gss_server_identity; + else if (options.gss_trust_dns) + gss_host = get_canonical_hostname(1); + else + gss_host = authctxt->host; /* Try one GSSAPI method at a time, rather than sending them all at * once. */ if (gss_supported == NULL) - gss_indicate_mechs(&min, &gss_supported); + if (GSS_ERROR(gss_indicate_mechs(&min, &gss_supported))) { + gss_supported = NULL; + return 0; + } /* Check to see if the mechanism is usable before we offer it */ while (mech < gss_supported->count && !ok) { /* My DER encoding requires length<128 */ if (gss_supported->elements[mech].length < 128 && ssh_gssapi_check_mechanism(&gssctxt, - &gss_supported->elements[mech], authctxt->host)) { + &gss_supported->elements[mech], gss_host, + options.gss_client_identity)) { ok = 1; /* Mechanism works */ } else { mech++; @@ -765,8 +835,8 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt) { Authctxt *authctxt = ctxt; Gssctxt *gssctxt; - int oidlen; - char *oidv; + u_int oidlen; + u_char *oidv; if (authctxt == NULL) fatal("input_gssapi_response: no authentication context"); @@ -879,6 +949,48 @@ input_gssapi_error(int type, u_int32_t plen, void *ctxt) free(lang); return 0; } + +int +userauth_gsskeyex(Authctxt *authctxt) +{ + Buffer b; + gss_buffer_desc gssbuf; + gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; + OM_uint32 ms; + + static int attempt = 0; + if (attempt++ >= 1) + return (0); + + if (gss_kex_context == NULL) { + debug("No valid Key exchange context"); + return (0); + } + + ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, + "gssapi-keyex"); + + gssbuf.value = buffer_ptr(&b); + gssbuf.length = buffer_len(&b); + + if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { + buffer_free(&b); + return (0); + } + + packet_start(SSH2_MSG_USERAUTH_REQUEST); + packet_put_cstring(authctxt->server_user); + packet_put_cstring(authctxt->service); + packet_put_cstring(authctxt->method->name); + packet_put_string(mic.value, mic.length); + packet_send(); + + buffer_free(&b); + gss_release_buffer(&ms, &mic); + + return (1); +} + #endif /* GSSAPI */ int diff --git a/sshd.c b/sshd.c index 430569c46..5cd9129d0 100644 --- a/sshd.c +++ b/sshd.c @@ -125,6 +125,10 @@ #include "version.h" #include "ssherr.h" +#ifdef USE_SECURITY_SESSION_API +#include +#endif + #ifndef O_NOCTTY #define O_NOCTTY 0 #endif @@ -1833,10 +1837,13 @@ main(int ac, char **av) logit("Disabling protocol version 1. Could not load host key"); options.protocol &= ~SSH_PROTO_1; } +#ifndef GSSAPI + /* The GSSAPI key exchange can run without a host key */ if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { logit("Disabling protocol version 2. Could not load host key"); options.protocol &= ~SSH_PROTO_2; } +#endif if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { logit("sshd: no hostkeys available -- exiting."); exit(1); @@ -2151,6 +2158,60 @@ main(int ac, char **av) remote_ip, remote_port, laddr, get_local_port()); free(laddr); +#ifdef USE_SECURITY_SESSION_API + /* + * Create a new security session for use by the new user login if + * the current session is the root session or we are not launched + * by inetd (eg: debugging mode or server mode). We do not + * necessarily need to create a session if we are launched from + * inetd because Panther xinetd will create a session for us. + * + * The only case where this logic will fail is if there is an + * inetd running in a non-root session which is not creating + * new sessions for us. Then all the users will end up in the + * same session (bad). + * + * When the client exits, the session will be destroyed for us + * automatically. + * + * We must create the session before any credentials are stored + * (including AFS pags, which happens a few lines below). + */ + { + OSStatus err = 0; + SecuritySessionId sid = 0; + SessionAttributeBits sattrs = 0; + + err = SessionGetInfo(callerSecuritySession, &sid, &sattrs); + if (err) + error("SessionGetInfo() failed with error %.8X", + (unsigned) err); + else + debug("Current Session ID is %.8X / Session Attributes are %.8X", + (unsigned) sid, (unsigned) sattrs); + + if (inetd_flag && !(sattrs & sessionIsRoot)) + debug("Running in inetd mode in a non-root session... " + "assuming inetd created the session for us."); + else { + debug("Creating new security session..."); + err = SessionCreate(0, sessionHasTTY | sessionIsRemote); + if (err) + error("SessionCreate() failed with error %.8X", + (unsigned) err); + + err = SessionGetInfo(callerSecuritySession, &sid, + &sattrs); + if (err) + error("SessionGetInfo() failed with error %.8X", + (unsigned) err); + else + debug("New Session ID is %.8X / Session Attributes are %.8X", + (unsigned) sid, (unsigned) sattrs); + } + } +#endif + /* * We don't want to listen forever unless the other side * successfully authenticates itself. So we set up an alarm which is @@ -2571,6 +2632,48 @@ do_ssh2_kex(void) myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal( list_hostkey_types()); +#ifdef GSSAPI + { + char *orig; + char *gss = NULL; + char *newstr = NULL; + orig = myproposal[PROPOSAL_KEX_ALGS]; + + /* + * If we don't have a host key, then there's no point advertising + * the other key exchange algorithms + */ + + if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0) + orig = NULL; + + if (options.gss_keyex) + gss = ssh_gssapi_server_mechanisms(); + else + gss = NULL; + + if (gss && orig) + xasprintf(&newstr, "%s,%s", gss, orig); + else if (gss) + newstr = gss; + else if (orig) + newstr = orig; + + /* + * If we've got GSSAPI mechanisms, then we've got the 'null' host + * key alg, but we can't tell people about it unless its the only + * host key algorithm we support + */ + if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0) + myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null"; + + if (newstr) + myproposal[PROPOSAL_KEX_ALGS] = newstr; + else + fatal("No supported key exchange algorithms"); + } +#endif + /* start key exchange */ if ((r = kex_setup(active_state, myproposal)) != 0) fatal("kex_setup: %s", ssh_err(r)); @@ -2585,6 +2688,13 @@ do_ssh2_kex(void) # endif #endif kex->kex[KEX_C25519_SHA256] = kexc25519_server; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server; + } +#endif kex->server = 1; kex->client_version_string=client_version_string; kex->server_version_string=server_version_string; diff --git a/sshd_config b/sshd_config index a848d73e4..f10329840 100644 --- a/sshd_config +++ b/sshd_config @@ -84,6 +84,8 @@ AuthorizedKeysFile .ssh/authorized_keys # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes +#GSSAPIStrictAcceptorCheck yes +#GSSAPIKeyExchange no # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will diff --git a/sshd_config.5 b/sshd_config.5 index a37a3aca3..c6d6858f9 100644 --- a/sshd_config.5 +++ b/sshd_config.5 @@ -623,6 +623,11 @@ The default is Specifies whether user authentication based on GSSAPI is allowed. The default is .Dq no . +.It Cm GSSAPIKeyExchange +Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange +doesn't rely on ssh keys to verify host identity. +The default is +.Dq no . .It Cm GSSAPICleanupCredentials Specifies whether to automatically destroy the user's credentials cache on logout. @@ -643,6 +648,11 @@ machine's default store. This facility is provided to assist with operation on multi homed machines. The default is .Dq yes . +.It Cm GSSAPIStoreCredentialsOnRekey +Controls whether the user's GSSAPI credentials should be updated following a +successful connection rekeying. This option can be used to accepted renewed +or updated credentials from a compatible client. The default is +.Dq no . .It Cm HostbasedAcceptedKeyTypes Specifies the key types that will be accepted for hostbased authentication as a comma-separated pattern list. diff --git a/sshkey.c b/sshkey.c index 87b093e91..e595b1149 100644 --- a/sshkey.c +++ b/sshkey.c @@ -115,6 +115,7 @@ static const struct keytype keytypes[] = { # endif /* OPENSSL_HAS_NISTP521 */ # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ + { "null", "null", KEY_NULL, 0, 0, 0 }, { NULL, NULL, -1, -1, 0, 0 } }; @@ -203,7 +204,7 @@ key_alg_list(int certs_only, int plain_only) const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { - if (kt->name == NULL || kt->sigonly) + if (kt->name == NULL || kt->sigonly || kt->type == KEY_NULL) continue; if ((certs_only && !kt->cert) || (plain_only && kt->cert)) continue; diff --git a/sshkey.h b/sshkey.h index a20a14f9e..2259cbb62 100644 --- a/sshkey.h +++ b/sshkey.h @@ -62,6 +62,7 @@ enum sshkey_types { KEY_DSA_CERT, KEY_ECDSA_CERT, KEY_ED25519_CERT, + KEY_NULL, KEY_UNSPEC }; -- cgit v1.2.3 From a00cba810338ce920de432e7797a45794bf280ba Mon Sep 17 00:00:00 2001 From: Manoj Srivastava Date: Sun, 9 Feb 2014 16:09:49 +0000 Subject: Handle SELinux authorisation roles Rejected upstream due to discomfort with magic usernames; a better approach will need an SSH protocol change. In the meantime, this came from Debian's SELinux maintainer, so we'll keep it until we have something better. Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1641 Bug-Debian: http://bugs.debian.org/394795 Last-Update: 2015-08-19 Patch-Name: selinux-role.patch --- auth.h | 1 + auth1.c | 8 +++++++- auth2.c | 10 ++++++++-- monitor.c | 32 +++++++++++++++++++++++++++++--- monitor.h | 2 ++ monitor_wrap.c | 22 ++++++++++++++++++++-- monitor_wrap.h | 3 ++- openbsd-compat/port-linux.c | 27 ++++++++++++++++++++------- openbsd-compat/port-linux.h | 4 ++-- platform.c | 4 ++-- platform.h | 2 +- session.c | 10 +++++----- session.h | 2 +- sshd.c | 2 +- sshpty.c | 4 ++-- sshpty.h | 2 +- 16 files changed, 104 insertions(+), 31 deletions(-) (limited to 'monitor_wrap.h') diff --git a/auth.h b/auth.h index 2160154f4..3b3a0853e 100644 --- a/auth.h +++ b/auth.h @@ -62,6 +62,7 @@ struct Authctxt { char *service; struct passwd *pw; /* set if 'valid' */ char *style; + char *role; void *kbdintctxt; char *info; /* Extra info for next auth_log */ #ifdef BSD_AUTH diff --git a/auth1.c b/auth1.c index 5073c49bb..dd0064832 100644 --- a/auth1.c +++ b/auth1.c @@ -383,7 +383,7 @@ void do_authentication(Authctxt *authctxt) { u_int ulen; - char *user, *style = NULL; + char *user, *style = NULL, *role = NULL; /* Get the name of the user that we wish to log in as. */ packet_read_expect(SSH_CMSG_USER); @@ -392,11 +392,17 @@ do_authentication(Authctxt *authctxt) user = packet_get_cstring(&ulen); packet_check_eom(); + if ((role = strchr(user, '/')) != NULL) + *role++ = '\0'; + if ((style = strchr(user, ':')) != NULL) *style++ = '\0'; + else if (role && (style = strchr(role, ':')) != NULL) + *style++ = '\0'; authctxt->user = user; authctxt->style = style; + authctxt->role = role; /* Verify that the user is a valid user. */ if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL) diff --git a/auth2.c b/auth2.c index 3f49bdca0..6eb3cc7b9 100644 --- a/auth2.c +++ b/auth2.c @@ -216,7 +216,7 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt) { Authctxt *authctxt = ctxt; Authmethod *m = NULL; - char *user, *service, *method, *style = NULL; + char *user, *service, *method, *style = NULL, *role = NULL; int authenticated = 0; if (authctxt == NULL) @@ -228,8 +228,13 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt) debug("userauth-request for user %s service %s method %s", user, service, method); debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); + if ((role = strchr(user, '/')) != NULL) + *role++ = 0; + if ((style = strchr(user, ':')) != NULL) *style++ = 0; + else if (role && (style = strchr(role, ':')) != NULL) + *style++ = '\0'; if (authctxt->attempt++ == 0) { /* setup auth context */ @@ -253,8 +258,9 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt) use_privsep ? " [net]" : ""); authctxt->service = xstrdup(service); authctxt->style = style ? xstrdup(style) : NULL; + authctxt->role = role ? xstrdup(role) : NULL; if (use_privsep) - mm_inform_authserv(service, style); + mm_inform_authserv(service, style, role); userauth_banner(); if (auth2_setup_methods_lists(authctxt) != 0) packet_disconnect("no authentication methods enabled"); diff --git a/monitor.c b/monitor.c index 6c8202325..5be3fbfdb 100644 --- a/monitor.c +++ b/monitor.c @@ -126,6 +126,7 @@ int mm_answer_sign(int, Buffer *); int mm_answer_pwnamallow(int, Buffer *); int mm_answer_auth2_read_banner(int, Buffer *); int mm_answer_authserv(int, Buffer *); +int mm_answer_authrole(int, Buffer *); int mm_answer_authpassword(int, Buffer *); int mm_answer_bsdauthquery(int, Buffer *); int mm_answer_bsdauthrespond(int, Buffer *); @@ -207,6 +208,7 @@ struct mon_table mon_dispatch_proto20[] = { {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, + {MONITOR_REQ_AUTHROLE, MON_ONCE, mm_answer_authrole}, {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, #ifdef USE_PAM @@ -875,6 +877,7 @@ mm_answer_pwnamallow(int sock, Buffer *m) else { /* Allow service/style information on the auth context */ monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); + monitor_permit(mon_dispatch, MONITOR_REQ_AUTHROLE, 1); monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); } #ifdef USE_PAM @@ -905,14 +908,37 @@ mm_answer_authserv(int sock, Buffer *m) authctxt->service = buffer_get_string(m, NULL); authctxt->style = buffer_get_string(m, NULL); - debug3("%s: service=%s, style=%s", - __func__, authctxt->service, authctxt->style); + authctxt->role = buffer_get_string(m, NULL); + debug3("%s: service=%s, style=%s, role=%s", + __func__, authctxt->service, authctxt->style, authctxt->role); if (strlen(authctxt->style) == 0) { free(authctxt->style); authctxt->style = NULL; } + if (strlen(authctxt->role) == 0) { + free(authctxt->role); + authctxt->role = NULL; + } + + return (0); +} + +int +mm_answer_authrole(int sock, Buffer *m) +{ + monitor_permit_authentications(1); + + authctxt->role = buffer_get_string(m, NULL); + debug3("%s: role=%s", + __func__, authctxt->role); + + if (strlen(authctxt->role) == 0) { + free(authctxt->role); + authctxt->role = NULL; + } + return (0); } @@ -1541,7 +1567,7 @@ mm_answer_pty(int sock, Buffer *m) res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); if (res == 0) goto error; - pty_setowner(authctxt->pw, s->tty); + pty_setowner(authctxt->pw, s->tty, authctxt->role); buffer_put_int(m, 1); buffer_put_cstring(m, s->tty); diff --git a/monitor.h b/monitor.h index bc50ade1f..2d82b8b84 100644 --- a/monitor.h +++ b/monitor.h @@ -68,6 +68,8 @@ enum monitor_reqtype { MONITOR_REQ_GSSSIGN = 150, MONITOR_ANS_GSSSIGN = 151, MONITOR_REQ_GSSUPCREDS = 152, MONITOR_ANS_GSSUPCREDS = 153, + MONITOR_REQ_AUTHROLE = 154, + }; struct mm_master; diff --git a/monitor_wrap.c b/monitor_wrap.c index 74fbd2ef3..eaf0a1294 100644 --- a/monitor_wrap.c +++ b/monitor_wrap.c @@ -327,10 +327,10 @@ mm_auth2_read_banner(void) return (banner); } -/* Inform the privileged process about service and style */ +/* Inform the privileged process about service, style, and role */ void -mm_inform_authserv(char *service, char *style) +mm_inform_authserv(char *service, char *style, char *role) { Buffer m; @@ -339,12 +339,30 @@ mm_inform_authserv(char *service, char *style) buffer_init(&m); buffer_put_cstring(&m, service); buffer_put_cstring(&m, style ? style : ""); + buffer_put_cstring(&m, role ? role : ""); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m); buffer_free(&m); } +/* Inform the privileged process about role */ + +void +mm_inform_authrole(char *role) +{ + Buffer m; + + debug3("%s entering", __func__); + + buffer_init(&m); + buffer_put_cstring(&m, role ? role : ""); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHROLE, &m); + + buffer_free(&m); +} + /* Do the password authentication */ int mm_auth_password(Authctxt *authctxt, char *password) diff --git a/monitor_wrap.h b/monitor_wrap.h index 403f8d00c..d9de551c2 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -41,7 +41,8 @@ void mm_log_handler(LogLevel, const char *, void *); int mm_is_monitor(void); DH *mm_choose_dh(int, int, int); int mm_key_sign(Key *, u_char **, u_int *, const u_char *, u_int, const char *); -void mm_inform_authserv(char *, char *); +void mm_inform_authserv(char *, char *, char *); +void mm_inform_authrole(char *); struct passwd *mm_getpwnamallow(const char *); char *mm_auth2_read_banner(void); int mm_auth_password(struct Authctxt *, char *); diff --git a/openbsd-compat/port-linux.c b/openbsd-compat/port-linux.c index f36999d7a..f9cdc15c3 100644 --- a/openbsd-compat/port-linux.c +++ b/openbsd-compat/port-linux.c @@ -29,6 +29,12 @@ #include #include +#ifdef WITH_SELINUX +#include "key.h" +#include "hostfile.h" +#include "auth.h" +#endif + #include "log.h" #include "xmalloc.h" #include "port-linux.h" @@ -58,7 +64,7 @@ ssh_selinux_enabled(void) /* Return the default security context for the given username */ static security_context_t -ssh_selinux_getctxbyname(char *pwname) +ssh_selinux_getctxbyname(char *pwname, const char *role) { security_context_t sc = NULL; char *sename = NULL, *lvl = NULL; @@ -73,9 +79,16 @@ ssh_selinux_getctxbyname(char *pwname) #endif #ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL - r = get_default_context_with_level(sename, lvl, NULL, &sc); + if (role != NULL && role[0]) + r = get_default_context_with_rolelevel(sename, role, lvl, NULL, + &sc); + else + r = get_default_context_with_level(sename, lvl, NULL, &sc); #else - r = get_default_context(sename, NULL, &sc); + if (role != NULL && role[0]) + r = get_default_context_with_role(sename, role, NULL, &sc); + else + r = get_default_context(sename, NULL, &sc); #endif if (r != 0) { @@ -105,7 +118,7 @@ ssh_selinux_getctxbyname(char *pwname) /* Set the execution context to the default for the specified user */ void -ssh_selinux_setup_exec_context(char *pwname) +ssh_selinux_setup_exec_context(char *pwname, const char *role) { security_context_t user_ctx = NULL; @@ -114,7 +127,7 @@ ssh_selinux_setup_exec_context(char *pwname) debug3("%s: setting execution context", __func__); - user_ctx = ssh_selinux_getctxbyname(pwname); + user_ctx = ssh_selinux_getctxbyname(pwname, role); if (setexeccon(user_ctx) != 0) { switch (security_getenforce()) { case -1: @@ -136,7 +149,7 @@ ssh_selinux_setup_exec_context(char *pwname) /* Set the TTY context for the specified user */ void -ssh_selinux_setup_pty(char *pwname, const char *tty) +ssh_selinux_setup_pty(char *pwname, const char *tty, const char *role) { security_context_t new_tty_ctx = NULL; security_context_t user_ctx = NULL; @@ -147,7 +160,7 @@ ssh_selinux_setup_pty(char *pwname, const char *tty) debug3("%s: setting TTY context on %s", __func__, tty); - user_ctx = ssh_selinux_getctxbyname(pwname); + user_ctx = ssh_selinux_getctxbyname(pwname, role); /* XXX: should these calls fatal() upon failure in enforcing mode? */ diff --git a/openbsd-compat/port-linux.h b/openbsd-compat/port-linux.h index e3d1004aa..80ce13ad9 100644 --- a/openbsd-compat/port-linux.h +++ b/openbsd-compat/port-linux.h @@ -21,8 +21,8 @@ #ifdef WITH_SELINUX int ssh_selinux_enabled(void); -void ssh_selinux_setup_pty(char *, const char *); -void ssh_selinux_setup_exec_context(char *); +void ssh_selinux_setup_pty(char *, const char *, const char *); +void ssh_selinux_setup_exec_context(char *, const char *); void ssh_selinux_change_context(const char *); void ssh_selinux_setfscreatecon(const char *); #endif diff --git a/platform.c b/platform.c index ee313da55..f35ec39a8 100644 --- a/platform.c +++ b/platform.c @@ -143,7 +143,7 @@ platform_setusercontext(struct passwd *pw) * called if sshd is running as root. */ void -platform_setusercontext_post_groups(struct passwd *pw) +platform_setusercontext_post_groups(struct passwd *pw, const char *role) { #if !defined(HAVE_LOGIN_CAP) && defined(USE_PAM) /* @@ -184,7 +184,7 @@ platform_setusercontext_post_groups(struct passwd *pw) } #endif /* HAVE_SETPCRED */ #ifdef WITH_SELINUX - ssh_selinux_setup_exec_context(pw->pw_name); + ssh_selinux_setup_exec_context(pw->pw_name, role); #endif } diff --git a/platform.h b/platform.h index e687c99b6..823901b65 100644 --- a/platform.h +++ b/platform.h @@ -27,7 +27,7 @@ void platform_post_fork_parent(pid_t child_pid); void platform_post_fork_child(void); int platform_privileged_uidswap(void); void platform_setusercontext(struct passwd *); -void platform_setusercontext_post_groups(struct passwd *); +void platform_setusercontext_post_groups(struct passwd *, const char *); char *platform_get_krb5_client(const char *); char *platform_krb5_get_principal_name(const char *); int platform_sys_dir_uid(uid_t); diff --git a/session.c b/session.c index 7a02500ab..99ec6f363 100644 --- a/session.c +++ b/session.c @@ -1489,7 +1489,7 @@ safely_chroot(const char *path, uid_t uid) /* Set login name, uid, gid, and groups. */ void -do_setusercontext(struct passwd *pw) +do_setusercontext(struct passwd *pw, const char *role) { char *chroot_path, *tmp; @@ -1517,7 +1517,7 @@ do_setusercontext(struct passwd *pw) endgrent(); #endif - platform_setusercontext_post_groups(pw); + platform_setusercontext_post_groups(pw, role); if (!in_chroot && options.chroot_directory != NULL && strcasecmp(options.chroot_directory, "none") != 0) { @@ -1674,7 +1674,7 @@ do_child(Session *s, const char *command) /* Force a password change */ if (s->authctxt->force_pwchange) { - do_setusercontext(pw); + do_setusercontext(pw, s->authctxt->role); child_close_fds(); do_pwchange(s); exit(1); @@ -1701,7 +1701,7 @@ do_child(Session *s, const char *command) /* When PAM is enabled we rely on it to do the nologin check */ if (!options.use_pam) do_nologin(pw); - do_setusercontext(pw); + do_setusercontext(pw, s->authctxt->role); /* * PAM session modules in do_setusercontext may have * generated messages, so if this in an interactive @@ -2112,7 +2112,7 @@ session_pty_req(Session *s) tty_parse_modes(s->ttyfd, &n_bytes); if (!use_privsep) - pty_setowner(s->pw, s->tty); + pty_setowner(s->pw, s->tty, s->authctxt->role); /* Set window size from the packet. */ pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); diff --git a/session.h b/session.h index 6a2f35e41..ef6593c34 100644 --- a/session.h +++ b/session.h @@ -77,7 +77,7 @@ void session_pty_cleanup2(Session *); Session *session_new(void); Session *session_by_tty(char *); void session_close(Session *); -void do_setusercontext(struct passwd *); +void do_setusercontext(struct passwd *, const char *); void child_set_env(char ***envp, u_int *envsizep, const char *name, const char *value); diff --git a/sshd.c b/sshd.c index d1dd711fc..bb093ccc0 100644 --- a/sshd.c +++ b/sshd.c @@ -781,7 +781,7 @@ privsep_postauth(Authctxt *authctxt) explicit_bzero(rnd, sizeof(rnd)); /* Drop privileges */ - do_setusercontext(authctxt->pw); + do_setusercontext(authctxt->pw, authctxt->role); skip: /* It is safe now to apply the key state */ diff --git a/sshpty.c b/sshpty.c index 15da8c649..e89efb74a 100644 --- a/sshpty.c +++ b/sshpty.c @@ -187,7 +187,7 @@ pty_change_window_size(int ptyfd, u_int row, u_int col, } void -pty_setowner(struct passwd *pw, const char *tty) +pty_setowner(struct passwd *pw, const char *tty, const char *role) { struct group *grp; gid_t gid; @@ -209,7 +209,7 @@ pty_setowner(struct passwd *pw, const char *tty) strerror(errno)); #ifdef WITH_SELINUX - ssh_selinux_setup_pty(pw->pw_name, tty); + ssh_selinux_setup_pty(pw->pw_name, tty, role); #endif if (st.st_uid != pw->pw_uid || st.st_gid != gid) { diff --git a/sshpty.h b/sshpty.h index cfa322480..edf24365f 100644 --- a/sshpty.h +++ b/sshpty.h @@ -24,4 +24,4 @@ int pty_allocate(int *, int *, char *, size_t); void pty_release(const char *); void pty_make_controlling_tty(int *, const char *); void pty_change_window_size(int, u_int, u_int, u_int, u_int); -void pty_setowner(struct passwd *, const char *); +void pty_setowner(struct passwd *, const char *, const char *); -- cgit v1.2.3