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authorColin Watson <cjwatson@debian.org>2015-08-19 14:23:50 +0100
committerColin Watson <cjwatson@debian.org>2015-08-19 14:23:50 +0100
commitbaccdb349b31c47cd76fb63211f754ed33a9707e (patch)
treed03653f975fd4eb8bf71bb0c9d168614401202fa /kexdhs.c
parent487bdb3a5ef6075887b830ccb8a0b14f6da78e93 (diff)
parent9f82e5a9042f2d872e98f48a876fcab3e25dd9bb (diff)
Import openssh_6.8p1.orig.tar.gz
Diffstat (limited to 'kexdhs.c')
-rw-r--r--kexdhs.c190
1 files changed, 123 insertions, 67 deletions
diff --git a/kexdhs.c b/kexdhs.c
index c3011f741..de7c05b17 100644
--- a/kexdhs.c
+++ b/kexdhs.c
@@ -1,4 +1,4 @@
1/* $OpenBSD: kexdhs.c,v 1.18 2014/02/02 03:44:31 djm Exp $ */ 1/* $OpenBSD: kexdhs.c,v 1.22 2015/01/26 06:10:03 djm Exp $ */
2/* 2/*
3 * Copyright (c) 2001 Markus Friedl. All rights reserved. 3 * Copyright (c) 2001 Markus Friedl. All rights reserved.
4 * 4 *
@@ -25,6 +25,8 @@
25 25
26#include "includes.h" 26#include "includes.h"
27 27
28#ifdef WITH_OPENSSL
29
28#include <sys/types.h> 30#include <sys/types.h>
29 31
30#include <stdarg.h> 32#include <stdarg.h>
@@ -33,55 +35,89 @@
33 35
34#include <openssl/dh.h> 36#include <openssl/dh.h>
35 37
36#include "xmalloc.h" 38#include "sshkey.h"
37#include "buffer.h"
38#include "key.h"
39#include "cipher.h" 39#include "cipher.h"
40#include "digest.h"
40#include "kex.h" 41#include "kex.h"
41#include "log.h" 42#include "log.h"
42#include "packet.h" 43#include "packet.h"
43#include "dh.h" 44#include "dh.h"
44#include "ssh2.h" 45#include "ssh2.h"
45 46
46void 47#include "dispatch.h"
47kexdh_server(Kex *kex) 48#include "compat.h"
49#include "ssherr.h"
50#include "sshbuf.h"
51
52static int input_kex_dh_init(int, u_int32_t, void *);
53
54int
55kexdh_server(struct ssh *ssh)
48{ 56{
49 BIGNUM *shared_secret = NULL, *dh_client_pub = NULL; 57 struct kex *kex = ssh->kex;
50 DH *dh; 58 int r;
51 Key *server_host_public, *server_host_private;
52 u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
53 u_int sbloblen, klen, hashlen, slen;
54 int kout;
55 59
56 /* generate server DH public key */ 60 /* generate server DH public key */
57 switch (kex->kex_type) { 61 switch (kex->kex_type) {
58 case KEX_DH_GRP1_SHA1: 62 case KEX_DH_GRP1_SHA1:
59 dh = dh_new_group1(); 63 kex->dh = dh_new_group1();
60 break; 64 break;
61 case KEX_DH_GRP14_SHA1: 65 case KEX_DH_GRP14_SHA1:
62 dh = dh_new_group14(); 66 kex->dh = dh_new_group14();
63 break; 67 break;
64 default: 68 default:
65 fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type); 69 r = SSH_ERR_INVALID_ARGUMENT;
70 goto out;
71 }
72 if (kex->dh == NULL) {
73 r = SSH_ERR_ALLOC_FAIL;
74 goto out;
66 } 75 }
67 dh_gen_key(dh, kex->we_need * 8); 76 if ((r = dh_gen_key(kex->dh, kex->we_need * 8)) != 0)
77 goto out;
68 78
69 debug("expecting SSH2_MSG_KEXDH_INIT"); 79 debug("expecting SSH2_MSG_KEXDH_INIT");
70 packet_read_expect(SSH2_MSG_KEXDH_INIT); 80 ssh_dispatch_set(ssh, SSH2_MSG_KEXDH_INIT, &input_kex_dh_init);
81 r = 0;
82 out:
83 return r;
84}
85
86int
87input_kex_dh_init(int type, u_int32_t seq, void *ctxt)
88{
89 struct ssh *ssh = ctxt;
90 struct kex *kex = ssh->kex;
91 BIGNUM *shared_secret = NULL, *dh_client_pub = NULL;
92 struct sshkey *server_host_public, *server_host_private;
93 u_char *kbuf = NULL, *signature = NULL, *server_host_key_blob = NULL;
94 u_char hash[SSH_DIGEST_MAX_LENGTH];
95 size_t sbloblen, slen;
96 size_t klen = 0, hashlen;
97 int kout, r;
71 98
72 if (kex->load_host_public_key == NULL || 99 if (kex->load_host_public_key == NULL ||
73 kex->load_host_private_key == NULL) 100 kex->load_host_private_key == NULL) {
74 fatal("Cannot load hostkey"); 101 r = SSH_ERR_INVALID_ARGUMENT;
75 server_host_public = kex->load_host_public_key(kex->hostkey_type); 102 goto out;
76 if (server_host_public == NULL) 103 }
77 fatal("Unsupported hostkey type %d", kex->hostkey_type); 104 server_host_public = kex->load_host_public_key(kex->hostkey_type,
78 server_host_private = kex->load_host_private_key(kex->hostkey_type); 105 kex->hostkey_nid, ssh);
106 server_host_private = kex->load_host_private_key(kex->hostkey_type,
107 kex->hostkey_nid, ssh);
108 if (server_host_public == NULL) {
109 r = SSH_ERR_NO_HOSTKEY_LOADED;
110 goto out;
111 }
79 112
80 /* key, cert */ 113 /* key, cert */
81 if ((dh_client_pub = BN_new()) == NULL) 114 if ((dh_client_pub = BN_new()) == NULL) {
82 fatal("dh_client_pub == NULL"); 115 r = SSH_ERR_ALLOC_FAIL;
83 packet_get_bignum2(dh_client_pub); 116 goto out;
84 packet_check_eom(); 117 }
118 if ((r = sshpkt_get_bignum2(ssh, dh_client_pub)) != 0 ||
119 (r = sshpkt_get_end(ssh)) != 0)
120 goto out;
85 121
86#ifdef DEBUG_KEXDH 122#ifdef DEBUG_KEXDH
87 fprintf(stderr, "dh_client_pub= "); 123 fprintf(stderr, "dh_client_pub= ");
@@ -91,70 +127,90 @@ kexdh_server(Kex *kex)
91#endif 127#endif
92 128
93#ifdef DEBUG_KEXDH 129#ifdef DEBUG_KEXDH
94 DHparams_print_fp(stderr, dh); 130 DHparams_print_fp(stderr, kex->dh);
95 fprintf(stderr, "pub= "); 131 fprintf(stderr, "pub= ");
96 BN_print_fp(stderr, dh->pub_key); 132 BN_print_fp(stderr, kex->dh->pub_key);
97 fprintf(stderr, "\n"); 133 fprintf(stderr, "\n");
98#endif 134#endif
99 if (!dh_pub_is_valid(dh, dh_client_pub)) 135 if (!dh_pub_is_valid(kex->dh, dh_client_pub)) {
100 packet_disconnect("bad client public DH value"); 136 sshpkt_disconnect(ssh, "bad client public DH value");
137 r = SSH_ERR_MESSAGE_INCOMPLETE;
138 goto out;
139 }
101 140
102 klen = DH_size(dh); 141 klen = DH_size(kex->dh);
103 kbuf = xmalloc(klen); 142 if ((kbuf = malloc(klen)) == NULL ||
104 if ((kout = DH_compute_key(kbuf, dh_client_pub, dh)) < 0) 143 (shared_secret = BN_new()) == NULL) {
105 fatal("DH_compute_key: failed"); 144 r = SSH_ERR_ALLOC_FAIL;
145 goto out;
146 }
147 if ((kout = DH_compute_key(kbuf, dh_client_pub, kex->dh)) < 0 ||
148 BN_bin2bn(kbuf, kout, shared_secret) == NULL) {
149 r = SSH_ERR_LIBCRYPTO_ERROR;
150 goto out;
151 }
106#ifdef DEBUG_KEXDH 152#ifdef DEBUG_KEXDH
107 dump_digest("shared secret", kbuf, kout); 153 dump_digest("shared secret", kbuf, kout);
108#endif 154#endif
109 if ((shared_secret = BN_new()) == NULL) 155 if ((r = sshkey_to_blob(server_host_public, &server_host_key_blob,
110 fatal("kexdh_server: BN_new failed"); 156 &sbloblen)) != 0)
111 if (BN_bin2bn(kbuf, kout, shared_secret) == NULL) 157 goto out;
112 fatal("kexdh_server: BN_bin2bn failed");
113 explicit_bzero(kbuf, klen);
114 free(kbuf);
115
116 key_to_blob(server_host_public, &server_host_key_blob, &sbloblen);
117
118 /* calc H */ 158 /* calc H */
119 kex_dh_hash( 159 hashlen = sizeof(hash);
160 if ((r = kex_dh_hash(
120 kex->client_version_string, 161 kex->client_version_string,
121 kex->server_version_string, 162 kex->server_version_string,
122 buffer_ptr(&kex->peer), buffer_len(&kex->peer), 163 sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
123 buffer_ptr(&kex->my), buffer_len(&kex->my), 164 sshbuf_ptr(kex->my), sshbuf_len(kex->my),
124 server_host_key_blob, sbloblen, 165 server_host_key_blob, sbloblen,
125 dh_client_pub, 166 dh_client_pub,
126 dh->pub_key, 167 kex->dh->pub_key,
127 shared_secret, 168 shared_secret,
128 &hash, &hashlen 169 hash, &hashlen)) != 0)
129 ); 170 goto out;
130 BN_clear_free(dh_client_pub);
131 171
132 /* save session id := H */ 172 /* save session id := H */
133 if (kex->session_id == NULL) { 173 if (kex->session_id == NULL) {
134 kex->session_id_len = hashlen; 174 kex->session_id_len = hashlen;
135 kex->session_id = xmalloc(kex->session_id_len); 175 kex->session_id = malloc(kex->session_id_len);
176 if (kex->session_id == NULL) {
177 r = SSH_ERR_ALLOC_FAIL;
178 goto out;
179 }
136 memcpy(kex->session_id, hash, kex->session_id_len); 180 memcpy(kex->session_id, hash, kex->session_id_len);
137 } 181 }
138 182
139 /* sign H */ 183 /* sign H */
140 kex->sign(server_host_private, server_host_public, &signature, &slen, 184 if ((r = kex->sign(server_host_private, server_host_public,
141 hash, hashlen); 185 &signature, &slen, hash, hashlen, ssh->compat)) < 0)
186 goto out;
142 187
143 /* destroy_sensitive_data(); */ 188 /* destroy_sensitive_data(); */
144 189
145 /* send server hostkey, DH pubkey 'f' and singed H */ 190 /* send server hostkey, DH pubkey 'f' and singed H */
146 packet_start(SSH2_MSG_KEXDH_REPLY); 191 if ((r = sshpkt_start(ssh, SSH2_MSG_KEXDH_REPLY)) != 0 ||
147 packet_put_string(server_host_key_blob, sbloblen); 192 (r = sshpkt_put_string(ssh, server_host_key_blob, sbloblen)) != 0 ||
148 packet_put_bignum2(dh->pub_key); /* f */ 193 (r = sshpkt_put_bignum2(ssh, kex->dh->pub_key)) != 0 || /* f */
149 packet_put_string(signature, slen); 194 (r = sshpkt_put_string(ssh, signature, slen)) != 0 ||
150 packet_send(); 195 (r = sshpkt_send(ssh)) != 0)
151 196 goto out;
152 free(signature); 197
198 if ((r = kex_derive_keys_bn(ssh, hash, hashlen, shared_secret)) == 0)
199 r = kex_send_newkeys(ssh);
200 out:
201 explicit_bzero(hash, sizeof(hash));
202 DH_free(kex->dh);
203 kex->dh = NULL;
204 if (dh_client_pub)
205 BN_clear_free(dh_client_pub);
206 if (kbuf) {
207 explicit_bzero(kbuf, klen);
208 free(kbuf);
209 }
210 if (shared_secret)
211 BN_clear_free(shared_secret);
153 free(server_host_key_blob); 212 free(server_host_key_blob);
154 /* have keys, free DH */ 213 free(signature);
155 DH_free(dh); 214 return r;
156
157 kex_derive_keys_bn(kex, hash, hashlen, shared_secret);
158 BN_clear_free(shared_secret);
159 kex_finish(kex);
160} 215}
216#endif /* WITH_OPENSSL */