From ea11119eee3c5e2429b1f5f8688b25b028fa991a Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Tue, 23 Apr 2013 19:24:32 +1000 Subject: - djm@cvs.openbsd.org 2013/04/19 01:06:50 [authfile.c cipher.c cipher.h kex.c kex.h kexecdh.c kexecdhc.c kexecdhs.c] [key.c key.h mac.c mac.h packet.c ssh.1 ssh.c] add the ability to query supported ciphers, MACs, key type and KEX algorithms to ssh. Includes some refactoring of KEX and key type handling to be table-driven; ok markus@ --- kex.h | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'kex.h') diff --git a/kex.h b/kex.h index 46731fa45..680264af2 100644 --- a/kex.h +++ b/kex.h @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.h,v 1.54 2013/01/08 18:49:04 markus Exp $ */ +/* $OpenBSD: kex.h,v 1.55 2013/04/19 01:06:50 djm Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. @@ -40,8 +40,9 @@ #define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1" #define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256" #define KEX_RESUME "resume@appgate.com" -/* The following represents the family of ECDH methods */ -#define KEX_ECDH_SHA2_STEM "ecdh-sha2-" +#define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256" +#define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384" +#define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521" #define COMP_NONE 0 #define COMP_ZLIB 1 @@ -86,7 +87,7 @@ typedef struct Newkeys Newkeys; struct Enc { char *name; - Cipher *cipher; + const Cipher *cipher; int enabled; u_int key_len; u_int iv_len; @@ -131,6 +132,7 @@ struct Kex { sig_atomic_t done; int flags; const EVP_MD *evp_md; + int ec_nid; char *client_version_string; char *server_version_string; int (*verify_host_key)(Key *); @@ -141,6 +143,7 @@ struct Kex { }; int kex_names_valid(const char *); +char *kex_alg_list(void); Kex *kex_setup(char *[PROPOSAL_MAX]); void kex_finish(Kex *); @@ -170,11 +173,6 @@ void kex_ecdh_hash(const EVP_MD *, const EC_GROUP *, char *, char *, char *, int, char *, int, u_char *, int, const EC_POINT *, const EC_POINT *, const BIGNUM *, u_char **, u_int *); -int kex_ecdh_name_to_nid(const char *); -const EVP_MD *kex_ecdh_name_to_evpmd(const char *); -#else -# define kex_ecdh_name_to_nid(x) (-1) -# define kex_ecdh_name_to_evpmd(x) (NULL) #endif void -- cgit v1.2.3 From 85b45e09188e7a7fc8f0a900a4c6a0f04a5720a7 Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Sat, 20 Jul 2013 13:21:52 +1000 Subject: - markus@cvs.openbsd.org 2013/07/19 07:37:48 [auth.h kex.h kexdhs.c kexecdhs.c kexgexs.c monitor.c servconf.c] [servconf.h session.c sshd.c sshd_config.5] add ssh-agent(1) support to sshd(8); allows encrypted hostkeys, or hostkeys on smartcards; most of the work by Zev Weiss; bz #1974 ok djm@ --- ChangeLog | 9 +++++++ auth.h | 4 ++- kex.h | 3 ++- kexdhs.c | 10 +++---- kexecdhs.c | 10 +++---- kexgexs.c | 11 +++----- monitor.c | 18 ++++++++++--- servconf.c | 18 +++++++++++-- servconf.h | 3 ++- session.c | 10 ++++++- sshd.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++------ sshd_config.5 | 16 ++++++++++-- 12 files changed, 153 insertions(+), 42 deletions(-) (limited to 'kex.h') diff --git a/ChangeLog b/ChangeLog index 9530ef55f..fd66fed6d 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +20130720 + - (djm) OpenBSD CVS Sync + - markus@cvs.openbsd.org 2013/07/19 07:37:48 + [auth.h kex.h kexdhs.c kexecdhs.c kexgexs.c monitor.c servconf.c] + [servconf.h session.c sshd.c sshd_config.5] + add ssh-agent(1) support to sshd(8); allows encrypted hostkeys, + or hostkeys on smartcards; most of the work by Zev Weiss; bz #1974 + ok djm@ + 20130718 - (djm) OpenBSD CVS Sync - dtucker@cvs.openbsd.org 2013/06/10 19:19:44 diff --git a/auth.h b/auth.h index caf44adc0..80f089869 100644 --- a/auth.h +++ b/auth.h @@ -1,4 +1,4 @@ -/* $OpenBSD: auth.h,v 1.75 2013/06/21 00:34:49 djm Exp $ */ +/* $OpenBSD: auth.h,v 1.76 2013/07/19 07:37:48 markus Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. @@ -198,10 +198,12 @@ check_key_in_hostfiles(struct passwd *, Key *, const char *, /* hostkey handling */ Key *get_hostkey_by_index(int); +Key *get_hostkey_public_by_index(int); Key *get_hostkey_public_by_type(int); Key *get_hostkey_private_by_type(int); int get_hostkey_index(Key *); int ssh1_session_key(BIGNUM *); +void sshd_hostkey_sign(Key *, Key *, u_char **, u_int *, u_char *, u_int); /* debug messages during authentication */ void auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2))); diff --git a/kex.h b/kex.h index 680264af2..9f1e1adb3 100644 --- a/kex.h +++ b/kex.h @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.h,v 1.55 2013/04/19 01:06:50 djm Exp $ */ +/* $OpenBSD: kex.h,v 1.56 2013/07/19 07:37:48 markus Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. @@ -139,6 +139,7 @@ struct Kex { Key *(*load_host_public_key)(int); Key *(*load_host_private_key)(int); int (*host_key_index)(Key *); + void (*sign)(Key *, Key *, u_char **, u_int *, u_char *, u_int); void (*kex[KEX_MAX])(Kex *); }; diff --git a/kexdhs.c b/kexdhs.c index 15128632c..269d80900 100644 --- a/kexdhs.c +++ b/kexdhs.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexdhs.c,v 1.13 2013/05/17 00:13:13 djm Exp $ */ +/* $OpenBSD: kexdhs.c,v 1.14 2013/07/19 07:37:48 markus Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * @@ -80,9 +80,6 @@ kexdh_server(Kex *kex) if (server_host_public == NULL) fatal("Unsupported hostkey type %d", kex->hostkey_type); server_host_private = kex->load_host_private_key(kex->hostkey_type); - if (server_host_private == NULL) - fatal("Missing private key for hostkey type %d", - kex->hostkey_type); /* key, cert */ if ((dh_client_pub = BN_new()) == NULL) @@ -144,9 +141,8 @@ kexdh_server(Kex *kex) } /* sign H */ - if (PRIVSEP(key_sign(server_host_private, &signature, &slen, hash, - hashlen)) < 0) - fatal("kexdh_server: key_sign failed"); + kex->sign(server_host_private, server_host_public, &signature, &slen, + hash, hashlen); /* destroy_sensitive_data(); */ diff --git a/kexecdhs.c b/kexecdhs.c index c42dcf448..3a580aacf 100644 --- a/kexecdhs.c +++ b/kexecdhs.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexecdhs.c,v 1.4 2013/05/17 00:13:13 djm Exp $ */ +/* $OpenBSD: kexecdhs.c,v 1.5 2013/07/19 07:37:48 markus Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * Copyright (c) 2010 Damien Miller. All rights reserved. @@ -78,9 +78,6 @@ kexecdh_server(Kex *kex) if (server_host_public == NULL) fatal("Unsupported hostkey type %d", kex->hostkey_type); server_host_private = kex->load_host_private_key(kex->hostkey_type); - if (server_host_private == NULL) - fatal("Missing private key for hostkey type %d", - kex->hostkey_type); debug("expecting SSH2_MSG_KEX_ECDH_INIT"); packet_read_expect(SSH2_MSG_KEX_ECDH_INIT); @@ -139,9 +136,8 @@ kexecdh_server(Kex *kex) } /* sign H */ - if (PRIVSEP(key_sign(server_host_private, &signature, &slen, - hash, hashlen)) < 0) - fatal("kexdh_server: key_sign failed"); + kex->sign(server_host_private, server_host_public, &signature, &slen, + hash, hashlen); /* destroy_sensitive_data(); */ diff --git a/kexgexs.c b/kexgexs.c index a543dda82..4e473fc73 100644 --- a/kexgexs.c +++ b/kexgexs.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexgexs.c,v 1.15 2013/05/17 00:13:13 djm Exp $ */ +/* $OpenBSD: kexgexs.c,v 1.16 2013/07/19 07:37:48 markus Exp $ */ /* * Copyright (c) 2000 Niels Provos. All rights reserved. * Copyright (c) 2001 Markus Friedl. All rights reserved. @@ -68,10 +68,6 @@ kexgex_server(Kex *kex) if (server_host_public == NULL) fatal("Unsupported hostkey type %d", kex->hostkey_type); server_host_private = kex->load_host_private_key(kex->hostkey_type); - if (server_host_private == NULL) - fatal("Missing private key for hostkey type %d", - kex->hostkey_type); - type = packet_read(); switch (type) { @@ -187,9 +183,8 @@ kexgex_server(Kex *kex) } /* sign H */ - if (PRIVSEP(key_sign(server_host_private, &signature, &slen, hash, - hashlen)) < 0) - fatal("kexgex_server: key_sign failed"); + kex->sign(server_host_private, server_host_public, &signature, &slen, + hash, hashlen); /* destroy_sensitive_data(); */ diff --git a/monitor.c b/monitor.c index 0516f60a2..44dff98c9 100644 --- a/monitor.c +++ b/monitor.c @@ -1,4 +1,4 @@ -/* $OpenBSD: monitor.c,v 1.126 2013/06/21 00:34:49 djm Exp $ */ +/* $OpenBSD: monitor.c,v 1.127 2013/07/19 07:37:48 markus Exp $ */ /* * Copyright 2002 Niels Provos * Copyright 2002 Markus Friedl @@ -97,6 +97,7 @@ #include "ssh2.h" #include "jpake.h" #include "roaming.h" +#include "authfd.h" #ifdef GSSAPI static Gssctxt *gsscontext = NULL; @@ -686,6 +687,8 @@ mm_answer_moduli(int sock, Buffer *m) return (0); } +extern AuthenticationConnection *auth_conn; + int mm_answer_sign(int sock, Buffer *m) { @@ -714,10 +717,16 @@ mm_answer_sign(int sock, Buffer *m) memcpy(session_id2, p, session_id2_len); } - if ((key = get_hostkey_by_index(keyid)) == NULL) + if ((key = get_hostkey_by_index(keyid)) != NULL) { + if (key_sign(key, &signature, &siglen, p, datlen) < 0) + fatal("%s: key_sign failed", __func__); + } else if ((key = get_hostkey_public_by_index(keyid)) != NULL && + auth_conn != NULL) { + if (ssh_agent_sign(auth_conn, key, &signature, &siglen, p, + datlen) < 0) + fatal("%s: ssh_agent_sign failed", __func__); + } else fatal("%s: no hostkey from index %d", __func__, keyid); - if (key_sign(key, &signature, &siglen, p, datlen) < 0) - fatal("%s: key_sign failed", __func__); debug3("%s: signature %p(%u)", __func__, signature, siglen); @@ -1864,6 +1873,7 @@ mm_get_kex(Buffer *m) 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; + kex->sign = sshd_hostkey_sign; return (kex); } diff --git a/servconf.c b/servconf.c index 36b8efecf..747edde6c 100644 --- a/servconf.c +++ b/servconf.c @@ -1,5 +1,5 @@ -/* $OpenBSD: servconf.c,v 1.239 2013/05/17 00:13:14 djm Exp $ */ +/* $OpenBSD: servconf.c,v 1.240 2013/07/19 07:37:48 markus Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved @@ -79,6 +79,7 @@ initialize_server_options(ServerOptions *options) options->address_family = -1; options->num_host_key_files = 0; options->num_host_cert_files = 0; + options->host_key_agent = NULL; options->pid_file = NULL; options->server_key_bits = -1; options->login_grace_time = -1; @@ -344,7 +345,7 @@ typedef enum { sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile, sKexAlgorithms, sIPQoS, sVersionAddendum, sAuthorizedKeysCommand, sAuthorizedKeysCommandUser, - sAuthenticationMethods, + sAuthenticationMethods, sHostKeyAgent, sDeprecated, sUnsupported } ServerOpCodes; @@ -369,6 +370,7 @@ static struct { { "port", sPort, SSHCFG_GLOBAL }, { "hostkey", sHostKeyFile, SSHCFG_GLOBAL }, { "hostdsakey", sHostKeyFile, SSHCFG_GLOBAL }, /* alias */ + { "hostkeyagent", sHostKeyAgent, SSHCFG_GLOBAL }, { "pidfile", sPidFile, SSHCFG_GLOBAL }, { "serverkeybits", sServerKeyBits, SSHCFG_GLOBAL }, { "logingracetime", sLoginGraceTime, SSHCFG_GLOBAL }, @@ -978,6 +980,17 @@ process_server_config_line(ServerOptions *options, char *line, } break; + case sHostKeyAgent: + charptr = &options->host_key_agent; + arg = strdelim(&cp); + if (!arg || *arg == '\0') + fatal("%s line %d: missing socket name.", + filename, linenum); + if (*activep && *charptr == NULL) + *charptr = !strcmp(arg, SSH_AUTHSOCKET_ENV_NAME) ? + xstrdup(arg) : derelativise_path(arg); + break; + case sHostCertificate: intptr = &options->num_host_cert_files; if (*intptr >= MAX_HOSTKEYS) @@ -2011,6 +2024,7 @@ dump_config(ServerOptions *o) dump_cfg_string(sVersionAddendum, o->version_addendum); dump_cfg_string(sAuthorizedKeysCommand, o->authorized_keys_command); dump_cfg_string(sAuthorizedKeysCommandUser, o->authorized_keys_command_user); + dump_cfg_string(sHostKeyAgent, o->host_key_agent); /* string arguments requiring a lookup */ dump_cfg_string(sLogLevel, log_level_name(o->log_level)); diff --git a/servconf.h b/servconf.h index fc051bd4b..98aad8ba2 100644 --- a/servconf.h +++ b/servconf.h @@ -1,4 +1,4 @@ -/* $OpenBSD: servconf.h,v 1.108 2013/05/16 04:09:14 dtucker Exp $ */ +/* $OpenBSD: servconf.h,v 1.109 2013/07/19 07:37:48 markus Exp $ */ /* * Author: Tatu Ylonen @@ -65,6 +65,7 @@ typedef struct { int num_host_key_files; /* Number of files for host keys. */ char *host_cert_files[MAX_HOSTCERTS]; /* Files containing host certs. */ int num_host_cert_files; /* Number of files for host certs. */ + char *host_key_agent; /* ssh-agent socket for host keys. */ char *pid_file; /* Where to put our pid */ int server_key_bits;/* Size of the server key. */ int login_grace_time; /* Disconnect if no auth in this time diff --git a/session.c b/session.c index 1424825ca..d4b57bdfb 100644 --- a/session.c +++ b/session.c @@ -1,4 +1,4 @@ -/* $OpenBSD: session.c,v 1.265 2013/05/17 00:13:14 djm Exp $ */ +/* $OpenBSD: session.c,v 1.266 2013/07/19 07:37:48 markus Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved @@ -80,6 +80,7 @@ #include "hostfile.h" #include "auth.h" #include "auth-options.h" +#include "authfd.h" #include "pathnames.h" #include "log.h" #include "servconf.h" @@ -1589,6 +1590,13 @@ launch_login(struct passwd *pw, const char *hostname) static void child_close_fds(void) { + extern AuthenticationConnection *auth_conn; + + if (auth_conn) { + ssh_close_authentication_connection(auth_conn); + auth_conn = NULL; + } + if (packet_get_connection_in() == packet_get_connection_out()) close(packet_get_connection_in()); else { diff --git a/sshd.c b/sshd.c index 1306a62a7..174cc7a42 100644 --- a/sshd.c +++ b/sshd.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshd.c,v 1.403 2013/06/05 02:27:50 dtucker Exp $ */ +/* $OpenBSD: sshd.c,v 1.404 2013/07/19 07:37:48 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -106,6 +106,7 @@ #include "canohost.h" #include "hostfile.h" #include "auth.h" +#include "authfd.h" #include "misc.h" #include "msg.h" #include "dispatch.h" @@ -194,6 +195,10 @@ char *server_version_string = NULL; /* for rekeying XXX fixme */ Kex *xxx_kex; +/* Daemon's agent connection */ +AuthenticationConnection *auth_conn = NULL; +int have_agent = 0; + /* * Any really sensitive data in the application is contained in this * structure. The idea is that this structure could be locked into memory so @@ -206,6 +211,7 @@ struct { Key *server_key; /* ephemeral server key */ Key *ssh1_host_key; /* ssh1 host key */ Key **host_keys; /* all private host keys */ + Key **host_pubkeys; /* all public host keys */ Key **host_certificates; /* all public host certificates */ int have_ssh1_key; int have_ssh2_key; @@ -653,6 +659,8 @@ privsep_preauth(Authctxt *authctxt) debug2("Network child is on pid %ld", (long)pid); pmonitor->m_pid = pid; + if (have_agent) + auth_conn = ssh_get_authentication_connection(); if (box != NULL) ssh_sandbox_parent_preauth(box, pid); monitor_child_preauth(authctxt, pmonitor); @@ -766,6 +774,8 @@ list_hostkey_types(void) buffer_init(&b); for (i = 0; i < options.num_host_key_files; i++) { key = sensitive_data.host_keys[i]; + if (key == NULL) + key = sensitive_data.host_pubkeys[i]; if (key == NULL) continue; switch (key->type) { @@ -819,6 +829,8 @@ get_hostkey_by_type(int type, int need_private) break; default: key = sensitive_data.host_keys[i]; + if (key == NULL && !need_private) + key = sensitive_data.host_pubkeys[i]; break; } if (key != NULL && key->type == type) @@ -848,6 +860,14 @@ get_hostkey_by_index(int ind) return (sensitive_data.host_keys[ind]); } +Key * +get_hostkey_public_by_index(int ind) +{ + if (ind < 0 || ind >= options.num_host_key_files) + return (NULL); + return (sensitive_data.host_pubkeys[ind]); +} + int get_hostkey_index(Key *key) { @@ -860,6 +880,8 @@ get_hostkey_index(Key *key) } else { if (key == sensitive_data.host_keys[i]) return (i); + if (key == sensitive_data.host_pubkeys[i]) + return (i); } } return (-1); @@ -1344,6 +1366,8 @@ main(int ac, char **av) u_int64_t ibytes, obytes; mode_t new_umask; Key *key; + Key *pubkey; + int keytype; Authctxt *authctxt; struct connection_info *connection_info = get_connection_info(0, 0); @@ -1623,22 +1647,45 @@ main(int ac, char **av) } endpwent(); - /* load private host keys */ + /* load host keys */ sensitive_data.host_keys = xcalloc(options.num_host_key_files, sizeof(Key *)); - for (i = 0; i < options.num_host_key_files; i++) + sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files, + sizeof(Key *)); + for (i = 0; i < options.num_host_key_files; i++) { sensitive_data.host_keys[i] = NULL; + sensitive_data.host_pubkeys[i] = NULL; + } + + if (options.host_key_agent) { + if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME)) + setenv(SSH_AUTHSOCKET_ENV_NAME, + options.host_key_agent, 1); + have_agent = ssh_agent_present(); + } for (i = 0; i < options.num_host_key_files; i++) { key = key_load_private(options.host_key_files[i], "", NULL); + pubkey = key_load_public(options.host_key_files[i], NULL); sensitive_data.host_keys[i] = key; - if (key == NULL) { + sensitive_data.host_pubkeys[i] = pubkey; + + if (key == NULL && pubkey != NULL && pubkey->type != KEY_RSA1 && + have_agent) { + debug("will rely on agent for hostkey %s", + options.host_key_files[i]); + keytype = pubkey->type; + } else if (key != NULL) { + keytype = key->type; + } else { error("Could not load host key: %s", options.host_key_files[i]); sensitive_data.host_keys[i] = NULL; + sensitive_data.host_pubkeys[i] = NULL; continue; } - switch (key->type) { + + switch (keytype) { case KEY_RSA1: sensitive_data.ssh1_host_key = key; sensitive_data.have_ssh1_key = 1; @@ -1649,8 +1696,8 @@ main(int ac, char **av) sensitive_data.have_ssh2_key = 1; break; } - debug("private host key: #%d type %d %s", i, key->type, - key_type(key)); + debug("private host key: #%d type %d %s", i, keytype, + key_type(key ? key : pubkey)); } if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { logit("Disabling protocol version 1. Could not load host key"); @@ -2020,9 +2067,11 @@ main(int ac, char **av) buffer_init(&loginmsg); auth_debug_reset(); - if (use_privsep) + if (use_privsep) { if (privsep_preauth(authctxt) == 1) goto authenticated; + } else if (compat20 && have_agent) + auth_conn = ssh_get_authentication_connection(); /* perform the key exchange */ /* authenticate user and start session */ @@ -2336,6 +2385,23 @@ do_ssh1_kex(void) packet_write_wait(); } +void +sshd_hostkey_sign(Key *privkey, Key *pubkey, u_char **signature, u_int *slen, + u_char *data, u_int dlen) +{ + if (privkey) { + if (PRIVSEP(key_sign(privkey, signature, slen, data, dlen) < 0)) + fatal("%s: key_sign failed", __func__); + } else if (use_privsep) { + if (mm_key_sign(pubkey, signature, slen, data, dlen) < 0) + fatal("%s: pubkey_sign failed", __func__); + } else { + if (ssh_agent_sign(auth_conn, pubkey, signature, slen, data, + dlen)) + fatal("%s: ssh_agent_sign failed", __func__); + } +} + /* * SSH2 key exchange: diffie-hellman-group1-sha1 */ @@ -2386,6 +2452,7 @@ do_ssh2_kex(void) 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; + kex->sign = sshd_hostkey_sign; xxx_kex = kex; diff --git a/sshd_config.5 b/sshd_config.5 index 3807c0f3c..3abac6c10 100644 --- a/sshd_config.5 +++ b/sshd_config.5 @@ -33,8 +33,8 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: sshd_config.5,v 1.161 2013/06/27 14:05:37 jmc Exp $ -.Dd $Mdocdate: June 27 2013 $ +.\" $OpenBSD: sshd_config.5,v 1.162 2013/07/19 07:37:48 markus Exp $ +.Dd $Mdocdate: July 19 2013 $ .Dt SSHD_CONFIG 5 .Os .Sh NAME @@ -546,6 +546,18 @@ keys are used for version 1 and or .Dq rsa are used for version 2 of the SSH protocol. +It is also possible to specify public host key files instead. +In this case operations on the private key will be delegated +to an +.Xr ssh-agent 1 . +.It Cm HostKeyAgent +Identifies the UNIX-domain socket used to communicate +with an agent that has access to the private host keys. +If +.Dq SSH_AUTH_SOCK +is specified, the location of the socket will be read from the +.Ev SSH_AUTH_SOCK +environment variable. .It Cm IgnoreRhosts Specifies that .Pa .rhosts -- cgit v1.2.3