Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 1 | /* |
Ben Lindstrom | 4469723 | 2001-07-04 03:32:30 +0000 | [diff] [blame] | 2 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * 1. Redistributions of source code must retain the above copyright |
| 8 | * notice, this list of conditions and the following disclaimer. |
| 9 | * 2. Redistributions in binary form must reproduce the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer in the |
| 11 | * documentation and/or other materials provided with the distribution. |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 12 | * |
| 13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 23 | */ |
| 24 | |
| 25 | #include "includes.h" |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 26 | RCSID("$OpenBSD: kex.c,v 1.66 2006/03/07 09:07:40 djm Exp $"); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 27 | |
| 28 | #include <openssl/crypto.h> |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 29 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 30 | #include "ssh2.h" |
| 31 | #include "xmalloc.h" |
| 32 | #include "buffer.h" |
| 33 | #include "bufaux.h" |
| 34 | #include "packet.h" |
| 35 | #include "compat.h" |
| 36 | #include "cipher.h" |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 37 | #include "kex.h" |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 38 | #include "key.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 39 | #include "log.h" |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 40 | #include "mac.h" |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 41 | #include "match.h" |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 42 | #include "dispatch.h" |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 43 | #include "monitor.h" |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 44 | |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 45 | #define KEX_COOKIE_LEN 16 |
| 46 | |
Damien Miller | af87af1 | 2006-03-15 13:02:28 +1100 | [diff] [blame] | 47 | #ifdef HAVE_EVP_SHA256 |
| 48 | # define evp_ssh_sha256 EVP_sha256 |
| 49 | #else /* HAVE_EVP_SHA256 */ |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 50 | extern const EVP_MD *evp_ssh_sha256(void); |
Damien Miller | af87af1 | 2006-03-15 13:02:28 +1100 | [diff] [blame] | 51 | #endif /* HAVE_EVP_SHA256 */ |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 52 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 53 | /* prototype */ |
| 54 | static void kex_kexinit_finish(Kex *); |
| 55 | static void kex_choose_conf(Kex *); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 56 | |
| 57 | /* put algorithm proposal into buffer */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 58 | static void |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 59 | kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX]) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 60 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 61 | u_int i; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 62 | |
| 63 | buffer_clear(b); |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 64 | /* |
| 65 | * add a dummy cookie, the cookie will be overwritten by |
| 66 | * kex_send_kexinit(), each time a kexinit is set |
| 67 | */ |
| 68 | for (i = 0; i < KEX_COOKIE_LEN; i++) |
| 69 | buffer_put_char(b, 0); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 70 | for (i = 0; i < PROPOSAL_MAX; i++) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 71 | buffer_put_cstring(b, proposal[i]); |
| 72 | buffer_put_char(b, 0); /* first_kex_packet_follows */ |
| 73 | buffer_put_int(b, 0); /* uint32 reserved */ |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 74 | } |
| 75 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 76 | /* parse buffer and return algorithm proposal */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 77 | static char ** |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 78 | kex_buf2prop(Buffer *raw, int *first_kex_follows) |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 79 | { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 80 | Buffer b; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 81 | int i; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 82 | char **proposal; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 83 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 84 | proposal = xmalloc(PROPOSAL_MAX * sizeof(char *)); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 85 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 86 | buffer_init(&b); |
| 87 | buffer_append(&b, buffer_ptr(raw), buffer_len(raw)); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 88 | /* skip cookie */ |
| 89 | for (i = 0; i < KEX_COOKIE_LEN; i++) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 90 | buffer_get_char(&b); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 91 | /* extract kex init proposal strings */ |
| 92 | for (i = 0; i < PROPOSAL_MAX; i++) { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 93 | proposal[i] = buffer_get_string(&b,NULL); |
| 94 | debug2("kex_parse_kexinit: %s", proposal[i]); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 95 | } |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 96 | /* first kex follows / reserved */ |
| 97 | i = buffer_get_char(&b); |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 98 | if (first_kex_follows != NULL) |
| 99 | *first_kex_follows = i; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 100 | debug2("kex_parse_kexinit: first_kex_follows %d ", i); |
| 101 | i = buffer_get_int(&b); |
| 102 | debug2("kex_parse_kexinit: reserved %d ", i); |
| 103 | buffer_free(&b); |
| 104 | return proposal; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 105 | } |
| 106 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 107 | static void |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 108 | kex_prop_free(char **proposal) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 109 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 110 | u_int i; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 111 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 112 | for (i = 0; i < PROPOSAL_MAX; i++) |
| 113 | xfree(proposal[i]); |
| 114 | xfree(proposal); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 115 | } |
| 116 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 117 | static void |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 118 | kex_protocol_error(int type, u_int32_t seq, void *ctxt) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 119 | { |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 120 | error("Hm, kex protocol error: type %d seq %u", type, seq); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 121 | } |
| 122 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 123 | static void |
Damien Miller | bc27d4e | 2002-02-13 13:54:06 +1100 | [diff] [blame] | 124 | kex_reset_dispatch(void) |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 125 | { |
Damien Miller | 7d05339 | 2002-01-22 23:24:13 +1100 | [diff] [blame] | 126 | dispatch_range(SSH2_MSG_TRANSPORT_MIN, |
| 127 | SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error); |
Damien Miller | bc27d4e | 2002-02-13 13:54:06 +1100 | [diff] [blame] | 128 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 129 | } |
| 130 | |
| 131 | void |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 132 | kex_finish(Kex *kex) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 133 | { |
Damien Miller | bc27d4e | 2002-02-13 13:54:06 +1100 | [diff] [blame] | 134 | kex_reset_dispatch(); |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 135 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 136 | packet_start(SSH2_MSG_NEWKEYS); |
| 137 | packet_send(); |
| 138 | /* packet_write_wait(); */ |
| 139 | debug("SSH2_MSG_NEWKEYS sent"); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 140 | |
Ben Lindstrom | 064496f | 2002-12-23 02:04:22 +0000 | [diff] [blame] | 141 | debug("expecting SSH2_MSG_NEWKEYS"); |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 142 | packet_read_expect(SSH2_MSG_NEWKEYS); |
Ben Lindstrom | 1451908 | 2002-02-26 17:58:29 +0000 | [diff] [blame] | 143 | packet_check_eom(); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 144 | debug("SSH2_MSG_NEWKEYS received"); |
Ben Lindstrom | 5ba23b3 | 2001-04-05 02:05:21 +0000 | [diff] [blame] | 145 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 146 | kex->done = 1; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 147 | buffer_clear(&kex->peer); |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 148 | /* buffer_clear(&kex->my); */ |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 149 | kex->flags &= ~KEX_INIT_SENT; |
Ben Lindstrom | 5ba23b3 | 2001-04-05 02:05:21 +0000 | [diff] [blame] | 150 | xfree(kex->name); |
| 151 | kex->name = NULL; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 152 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 153 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 154 | void |
| 155 | kex_send_kexinit(Kex *kex) |
| 156 | { |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 157 | u_int32_t rnd = 0; |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 158 | u_char *cookie; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 159 | u_int i; |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 160 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 161 | if (kex == NULL) { |
| 162 | error("kex_send_kexinit: no kex, cannot rekey"); |
| 163 | return; |
| 164 | } |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 165 | if (kex->flags & KEX_INIT_SENT) { |
| 166 | debug("KEX_INIT_SENT"); |
| 167 | return; |
| 168 | } |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 169 | kex->done = 0; |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 170 | |
| 171 | /* generate a random cookie */ |
| 172 | if (buffer_len(&kex->my) < KEX_COOKIE_LEN) |
| 173 | fatal("kex_send_kexinit: kex proposal too short"); |
| 174 | cookie = buffer_ptr(&kex->my); |
| 175 | for (i = 0; i < KEX_COOKIE_LEN; i++) { |
| 176 | if (i % 4 == 0) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 177 | rnd = arc4random(); |
| 178 | cookie[i] = rnd; |
| 179 | rnd >>= 8; |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 180 | } |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 181 | packet_start(SSH2_MSG_KEXINIT); |
| 182 | packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my)); |
| 183 | packet_send(); |
| 184 | debug("SSH2_MSG_KEXINIT sent"); |
| 185 | kex->flags |= KEX_INIT_SENT; |
| 186 | } |
| 187 | |
| 188 | void |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 189 | kex_input_kexinit(int type, u_int32_t seq, void *ctxt) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 190 | { |
| 191 | char *ptr; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 192 | u_int i, dlen; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 193 | Kex *kex = (Kex *)ctxt; |
| 194 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 195 | debug("SSH2_MSG_KEXINIT received"); |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 196 | if (kex == NULL) |
| 197 | fatal("kex_input_kexinit: no kex, cannot rekey"); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 198 | |
| 199 | ptr = packet_get_raw(&dlen); |
| 200 | buffer_append(&kex->peer, ptr, dlen); |
| 201 | |
Ben Lindstrom | 8e312f3 | 2001-04-04 23:50:21 +0000 | [diff] [blame] | 202 | /* discard packet */ |
| 203 | for (i = 0; i < KEX_COOKIE_LEN; i++) |
| 204 | packet_get_char(); |
| 205 | for (i = 0; i < PROPOSAL_MAX; i++) |
| 206 | xfree(packet_get_string(NULL)); |
Ben Lindstrom | c5a7f4f | 2002-06-25 23:19:13 +0000 | [diff] [blame] | 207 | (void) packet_get_char(); |
| 208 | (void) packet_get_int(); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 209 | packet_check_eom(); |
Ben Lindstrom | 8e312f3 | 2001-04-04 23:50:21 +0000 | [diff] [blame] | 210 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 211 | kex_kexinit_finish(kex); |
| 212 | } |
| 213 | |
| 214 | Kex * |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 215 | kex_setup(char *proposal[PROPOSAL_MAX]) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 216 | { |
| 217 | Kex *kex; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 218 | |
| 219 | kex = xmalloc(sizeof(*kex)); |
| 220 | memset(kex, 0, sizeof(*kex)); |
| 221 | buffer_init(&kex->peer); |
| 222 | buffer_init(&kex->my); |
| 223 | kex_prop2buf(&kex->my, proposal); |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 224 | kex->done = 0; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 225 | |
| 226 | kex_send_kexinit(kex); /* we start */ |
Damien Miller | bc27d4e | 2002-02-13 13:54:06 +1100 | [diff] [blame] | 227 | kex_reset_dispatch(); |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 228 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 229 | return kex; |
| 230 | } |
| 231 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 232 | static void |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 233 | kex_kexinit_finish(Kex *kex) |
| 234 | { |
| 235 | if (!(kex->flags & KEX_INIT_SENT)) |
| 236 | kex_send_kexinit(kex); |
| 237 | |
| 238 | kex_choose_conf(kex); |
| 239 | |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 240 | if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX && |
| 241 | kex->kex[kex->kex_type] != NULL) { |
| 242 | (kex->kex[kex->kex_type])(kex); |
| 243 | } else { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 244 | fatal("Unsupported key exchange %d", kex->kex_type); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 245 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 246 | } |
| 247 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 248 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 249 | choose_enc(Enc *enc, char *client, char *server) |
| 250 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 251 | char *name = match_list(client, server, NULL); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 252 | if (name == NULL) |
| 253 | fatal("no matching cipher found: client %s server %s", client, server); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 254 | if ((enc->cipher = cipher_by_name(name)) == NULL) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 255 | fatal("matching cipher is not supported: %s", name); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 256 | enc->name = name; |
| 257 | enc->enabled = 0; |
| 258 | enc->iv = NULL; |
| 259 | enc->key = NULL; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 260 | enc->key_len = cipher_keylen(enc->cipher); |
| 261 | enc->block_size = cipher_blocksize(enc->cipher); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 262 | } |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 263 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 264 | choose_mac(Mac *mac, char *client, char *server) |
| 265 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 266 | char *name = match_list(client, server, NULL); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 267 | if (name == NULL) |
| 268 | fatal("no matching mac found: client %s server %s", client, server); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 269 | if (mac_init(mac, name) < 0) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 270 | fatal("unsupported mac %s", name); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 271 | /* truncate the key */ |
| 272 | if (datafellows & SSH_BUG_HMAC) |
| 273 | mac->key_len = 16; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 274 | mac->name = name; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 275 | mac->key = NULL; |
| 276 | mac->enabled = 0; |
| 277 | } |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 278 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 279 | choose_comp(Comp *comp, char *client, char *server) |
| 280 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 281 | char *name = match_list(client, server, NULL); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 282 | if (name == NULL) |
| 283 | fatal("no matching comp found: client %s server %s", client, server); |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 284 | if (strcmp(name, "zlib@openssh.com") == 0) { |
| 285 | comp->type = COMP_DELAYED; |
| 286 | } else if (strcmp(name, "zlib") == 0) { |
| 287 | comp->type = COMP_ZLIB; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 288 | } else if (strcmp(name, "none") == 0) { |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 289 | comp->type = COMP_NONE; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 290 | } else { |
| 291 | fatal("unsupported comp %s", name); |
| 292 | } |
| 293 | comp->name = name; |
| 294 | } |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 295 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 296 | choose_kex(Kex *k, char *client, char *server) |
| 297 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 298 | k->name = match_list(client, server, NULL); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 299 | if (k->name == NULL) |
| 300 | fatal("no kex alg"); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 301 | if (strcmp(k->name, KEX_DH1) == 0) { |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 302 | k->kex_type = KEX_DH_GRP1_SHA1; |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 303 | k->evp_md = EVP_sha1(); |
Damien Miller | f675fc4 | 2004-06-15 10:30:09 +1000 | [diff] [blame] | 304 | } else if (strcmp(k->name, KEX_DH14) == 0) { |
| 305 | k->kex_type = KEX_DH_GRP14_SHA1; |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 306 | k->evp_md = EVP_sha1(); |
| 307 | } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) { |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 308 | k->kex_type = KEX_DH_GEX_SHA1; |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 309 | k->evp_md = EVP_sha1(); |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 310 | } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) { |
| 311 | k->kex_type = KEX_DH_GEX_SHA256; |
| 312 | k->evp_md = evp_ssh_sha256(); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 313 | } else |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 314 | fatal("bad kex alg %s", k->name); |
| 315 | } |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 316 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 317 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 318 | choose_hostkeyalg(Kex *k, char *client, char *server) |
| 319 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 320 | char *hostkeyalg = match_list(client, server, NULL); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 321 | if (hostkeyalg == NULL) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 322 | fatal("no hostkey alg"); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 323 | k->hostkey_type = key_type_from_name(hostkeyalg); |
| 324 | if (k->hostkey_type == KEY_UNSPEC) |
| 325 | fatal("bad hostkey alg '%s'", hostkeyalg); |
Ben Lindstrom | 48bd7c1 | 2001-01-09 00:35:42 +0000 | [diff] [blame] | 326 | xfree(hostkeyalg); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 327 | } |
| 328 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 329 | static int |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 330 | proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX]) |
| 331 | { |
| 332 | static int check[] = { |
| 333 | PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1 |
| 334 | }; |
| 335 | int *idx; |
| 336 | char *p; |
| 337 | |
| 338 | for (idx = &check[0]; *idx != -1; idx++) { |
| 339 | if ((p = strchr(my[*idx], ',')) != NULL) |
| 340 | *p = '\0'; |
| 341 | if ((p = strchr(peer[*idx], ',')) != NULL) |
| 342 | *p = '\0'; |
| 343 | if (strcmp(my[*idx], peer[*idx]) != 0) { |
| 344 | debug2("proposal mismatch: my %s peer %s", |
| 345 | my[*idx], peer[*idx]); |
| 346 | return (0); |
| 347 | } |
| 348 | } |
| 349 | debug2("proposals match"); |
| 350 | return (1); |
| 351 | } |
| 352 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 353 | static void |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 354 | kex_choose_conf(Kex *kex) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 355 | { |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 356 | Newkeys *newkeys; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 357 | char **my, **peer; |
| 358 | char **cprop, **sprop; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 359 | int nenc, nmac, ncomp; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 360 | u_int mode, ctos, need; |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 361 | int first_kex_follows, type; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 362 | |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 363 | my = kex_buf2prop(&kex->my, NULL); |
| 364 | peer = kex_buf2prop(&kex->peer, &first_kex_follows); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 365 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 366 | if (kex->server) { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 367 | cprop=peer; |
| 368 | sprop=my; |
| 369 | } else { |
| 370 | cprop=my; |
| 371 | sprop=peer; |
| 372 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 373 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 374 | /* Algorithm Negotiation */ |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 375 | for (mode = 0; mode < MODE_MAX; mode++) { |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 376 | newkeys = xmalloc(sizeof(*newkeys)); |
| 377 | memset(newkeys, 0, sizeof(*newkeys)); |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 378 | kex->newkeys[mode] = newkeys; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 379 | ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 380 | nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC; |
| 381 | nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC; |
| 382 | ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 383 | choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]); |
| 384 | choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]); |
| 385 | choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 386 | debug("kex: %s %s %s %s", |
| 387 | ctos ? "client->server" : "server->client", |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 388 | newkeys->enc.name, |
| 389 | newkeys->mac.name, |
| 390 | newkeys->comp.name); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 391 | } |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 392 | choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]); |
| 393 | choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS], |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 394 | sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 395 | need = 0; |
| 396 | for (mode = 0; mode < MODE_MAX; mode++) { |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 397 | newkeys = kex->newkeys[mode]; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 398 | if (need < newkeys->enc.key_len) |
| 399 | need = newkeys->enc.key_len; |
| 400 | if (need < newkeys->enc.block_size) |
| 401 | need = newkeys->enc.block_size; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 402 | if (need < newkeys->mac.key_len) |
| 403 | need = newkeys->mac.key_len; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 404 | } |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 405 | /* XXX need runden? */ |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 406 | kex->we_need = need; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 407 | |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 408 | /* ignore the next message if the proposals do not match */ |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 409 | if (first_kex_follows && !proposals_match(my, peer) && |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame] | 410 | !(datafellows & SSH_BUG_FIRSTKEX)) { |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 411 | type = packet_read(); |
| 412 | debug2("skipping next packet (type %u)", type); |
| 413 | } |
| 414 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 415 | kex_prop_free(my); |
| 416 | kex_prop_free(peer); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 417 | } |
| 418 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 419 | static u_char * |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 420 | derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen, |
| 421 | BIGNUM *shared_secret) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 422 | { |
| 423 | Buffer b; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 424 | EVP_MD_CTX md; |
| 425 | char c = id; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 426 | u_int have; |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 427 | int mdsz; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 428 | u_char *digest; |
Damien Miller | 46d38de | 2005-07-17 17:02:09 +1000 | [diff] [blame] | 429 | |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 430 | if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0) |
| 431 | fatal("bad kex md size %d", mdsz); |
| 432 | digest = xmalloc(roundup(need, mdsz)); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 433 | |
| 434 | buffer_init(&b); |
| 435 | buffer_put_bignum2(&b, shared_secret); |
| 436 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 437 | /* K1 = HASH(K || H || "A" || session_id) */ |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 438 | EVP_DigestInit(&md, kex->evp_md); |
Ben Lindstrom | 8c96392 | 2001-04-30 23:06:57 +0000 | [diff] [blame] | 439 | if (!(datafellows & SSH_BUG_DERIVEKEY)) |
| 440 | EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 441 | EVP_DigestUpdate(&md, hash, hashlen); |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 442 | EVP_DigestUpdate(&md, &c, 1); |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 443 | EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 444 | EVP_DigestFinal(&md, digest, NULL); |
| 445 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 446 | /* |
| 447 | * expand key: |
| 448 | * Kn = HASH(K || H || K1 || K2 || ... || Kn-1) |
| 449 | * Key = K1 || K2 || ... || Kn |
| 450 | */ |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 451 | for (have = mdsz; need > have; have += mdsz) { |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 452 | EVP_DigestInit(&md, kex->evp_md); |
Ben Lindstrom | 8c96392 | 2001-04-30 23:06:57 +0000 | [diff] [blame] | 453 | if (!(datafellows & SSH_BUG_DERIVEKEY)) |
| 454 | EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 455 | EVP_DigestUpdate(&md, hash, hashlen); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 456 | EVP_DigestUpdate(&md, digest, have); |
| 457 | EVP_DigestFinal(&md, digest + have, NULL); |
| 458 | } |
| 459 | buffer_free(&b); |
| 460 | #ifdef DEBUG_KEX |
| 461 | fprintf(stderr, "key '%c'== ", c); |
| 462 | dump_digest("key", digest, need); |
| 463 | #endif |
| 464 | return digest; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 465 | } |
| 466 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 467 | Newkeys *current_keys[MODE_MAX]; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 468 | |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 469 | #define NKEYS 6 |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 470 | void |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 471 | kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 472 | { |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 473 | u_char *keys[NKEYS]; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 474 | u_int i, mode, ctos; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 475 | |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 476 | for (i = 0; i < NKEYS; i++) { |
| 477 | keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen, |
| 478 | shared_secret); |
| 479 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 480 | |
Ben Lindstrom | 064496f | 2002-12-23 02:04:22 +0000 | [diff] [blame] | 481 | debug2("kex_derive_keys"); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 482 | for (mode = 0; mode < MODE_MAX; mode++) { |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 483 | current_keys[mode] = kex->newkeys[mode]; |
| 484 | kex->newkeys[mode] = NULL; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 485 | ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN); |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 486 | current_keys[mode]->enc.iv = keys[ctos ? 0 : 1]; |
| 487 | current_keys[mode]->enc.key = keys[ctos ? 2 : 3]; |
| 488 | current_keys[mode]->mac.key = keys[ctos ? 4 : 5]; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 489 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 490 | } |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 491 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 492 | Newkeys * |
| 493 | kex_get_newkeys(int mode) |
| 494 | { |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 495 | Newkeys *ret; |
| 496 | |
| 497 | ret = current_keys[mode]; |
| 498 | current_keys[mode] = NULL; |
| 499 | return ret; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 500 | } |
| 501 | |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 502 | void |
| 503 | derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus, |
| 504 | u_int8_t cookie[8], u_int8_t id[16]) |
| 505 | { |
| 506 | const EVP_MD *evp_md = EVP_md5(); |
| 507 | EVP_MD_CTX md; |
| 508 | u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE]; |
| 509 | int len; |
| 510 | |
| 511 | EVP_DigestInit(&md, evp_md); |
| 512 | |
| 513 | len = BN_num_bytes(host_modulus); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 514 | if (len < (512 / 8) || (u_int)len > sizeof(nbuf)) |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 515 | fatal("%s: bad host modulus (len %d)", __func__, len); |
| 516 | BN_bn2bin(host_modulus, nbuf); |
| 517 | EVP_DigestUpdate(&md, nbuf, len); |
| 518 | |
| 519 | len = BN_num_bytes(server_modulus); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 520 | if (len < (512 / 8) || (u_int)len > sizeof(nbuf)) |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 521 | fatal("%s: bad server modulus (len %d)", __func__, len); |
| 522 | BN_bn2bin(server_modulus, nbuf); |
| 523 | EVP_DigestUpdate(&md, nbuf, len); |
| 524 | |
| 525 | EVP_DigestUpdate(&md, cookie, 8); |
| 526 | |
Darren Tucker | b42714e | 2004-05-13 16:31:48 +1000 | [diff] [blame] | 527 | EVP_DigestFinal(&md, obuf, NULL); |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 528 | memcpy(id, obuf, 16); |
| 529 | |
| 530 | memset(nbuf, 0, sizeof(nbuf)); |
| 531 | memset(obuf, 0, sizeof(obuf)); |
| 532 | memset(&md, 0, sizeof(md)); |
| 533 | } |
| 534 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 535 | #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) |
| 536 | void |
| 537 | dump_digest(char *msg, u_char *digest, int len) |
| 538 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 539 | u_int i; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 540 | |
| 541 | fprintf(stderr, "%s\n", msg); |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 542 | for (i = 0; i< len; i++) { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 543 | fprintf(stderr, "%02x", digest[i]); |
| 544 | if (i%32 == 31) |
| 545 | fprintf(stderr, "\n"); |
| 546 | else if (i%8 == 7) |
| 547 | fprintf(stderr, " "); |
| 548 | } |
| 549 | fprintf(stderr, "\n"); |
| 550 | } |
| 551 | #endif |