Damien Miller | 690d989 | 2013-11-08 12:16:49 +1100 | [diff] [blame] | 1 | /* $OpenBSD: mac.c,v 1.25 2013/11/07 11:58:27 dtucker Exp $ */ |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2001 Markus Friedl. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 15 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 16 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 17 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 18 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 19 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 20 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 21 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 23 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 24 | */ |
| 25 | |
| 26 | #include "includes.h" |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 27 | |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 28 | #include <sys/types.h> |
| 29 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 30 | #include <openssl/hmac.h> |
| 31 | |
Damien Miller | ded319c | 2006-09-01 15:38:36 +1000 | [diff] [blame] | 32 | #include <stdarg.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 33 | #include <string.h> |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 34 | #include <signal.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 35 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 36 | #include "xmalloc.h" |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 37 | #include "log.h" |
| 38 | #include "cipher.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 39 | #include "buffer.h" |
| 40 | #include "key.h" |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 41 | #include "kex.h" |
| 42 | #include "mac.h" |
Damien Miller | 3f94188 | 2006-03-31 23:13:02 +1100 | [diff] [blame] | 43 | #include "misc.h" |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 44 | |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 45 | #include "umac.h" |
| 46 | |
Darren Tucker | e9b3ad7 | 2012-01-17 14:03:34 +1100 | [diff] [blame] | 47 | #include "openbsd-compat/openssl-compat.h" |
| 48 | |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 49 | #define SSH_EVP 1 /* OpenSSL EVP-based MAC */ |
| 50 | #define SSH_UMAC 2 /* UMAC (not integrated with OpenSSL) */ |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 51 | #define SSH_UMAC128 3 |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 52 | |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 53 | struct macalg { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 54 | char *name; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 55 | int type; |
Ben Lindstrom | 6a24641 | 2002-06-06 19:48:16 +0000 | [diff] [blame] | 56 | const EVP_MD * (*mdfunc)(void); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 57 | int truncatebits; /* truncate digest if != 0 */ |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 58 | int key_len; /* just for UMAC */ |
| 59 | int len; /* just for UMAC */ |
Damien Miller | 37834af | 2012-12-12 11:00:37 +1100 | [diff] [blame] | 60 | int etm; /* Encrypt-then-MAC */ |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 61 | }; |
| 62 | |
| 63 | static const struct macalg macs[] = { |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 64 | /* Encrypt-and-MAC (encrypt-and-authenticate) variants */ |
| 65 | { "hmac-sha1", SSH_EVP, EVP_sha1, 0, 0, 0, 0 }, |
| 66 | { "hmac-sha1-96", SSH_EVP, EVP_sha1, 96, 0, 0, 0 }, |
Tim Rice | a122682 | 2011-08-16 17:29:01 -0700 | [diff] [blame] | 67 | #ifdef HAVE_EVP_SHA256 |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 68 | { "hmac-sha2-256", SSH_EVP, EVP_sha256, 0, 0, 0, 0 }, |
| 69 | { "hmac-sha2-512", SSH_EVP, EVP_sha512, 0, 0, 0, 0 }, |
Tim Rice | a122682 | 2011-08-16 17:29:01 -0700 | [diff] [blame] | 70 | #endif |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 71 | { "hmac-md5", SSH_EVP, EVP_md5, 0, 0, 0, 0 }, |
| 72 | { "hmac-md5-96", SSH_EVP, EVP_md5, 96, 0, 0, 0 }, |
| 73 | { "hmac-ripemd160", SSH_EVP, EVP_ripemd160, 0, 0, 0, 0 }, |
| 74 | { "hmac-ripemd160@openssh.com", SSH_EVP, EVP_ripemd160, 0, 0, 0, 0 }, |
| 75 | { "umac-64@openssh.com", SSH_UMAC, NULL, 0, 128, 64, 0 }, |
| 76 | { "umac-128@openssh.com", SSH_UMAC128, NULL, 0, 128, 128, 0 }, |
| 77 | |
| 78 | /* Encrypt-then-MAC variants */ |
| 79 | { "hmac-sha1-etm@openssh.com", SSH_EVP, EVP_sha1, 0, 0, 0, 1 }, |
| 80 | { "hmac-sha1-96-etm@openssh.com", SSH_EVP, EVP_sha1, 96, 0, 0, 1 }, |
| 81 | #ifdef HAVE_EVP_SHA256 |
| 82 | { "hmac-sha2-256-etm@openssh.com", SSH_EVP, EVP_sha256, 0, 0, 0, 1 }, |
| 83 | { "hmac-sha2-512-etm@openssh.com", SSH_EVP, EVP_sha512, 0, 0, 0, 1 }, |
| 84 | #endif |
| 85 | { "hmac-md5-etm@openssh.com", SSH_EVP, EVP_md5, 0, 0, 0, 1 }, |
| 86 | { "hmac-md5-96-etm@openssh.com", SSH_EVP, EVP_md5, 96, 0, 0, 1 }, |
Damien Miller | 74f13bd | 2012-12-12 10:46:53 +1100 | [diff] [blame] | 87 | { "hmac-ripemd160-etm@openssh.com", SSH_EVP, EVP_ripemd160, 0, 0, 0, 1 }, |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 88 | { "umac-64-etm@openssh.com", SSH_UMAC, NULL, 0, 128, 64, 1 }, |
| 89 | { "umac-128-etm@openssh.com", SSH_UMAC128, NULL, 0, 128, 128, 1 }, |
| 90 | |
| 91 | { NULL, 0, NULL, 0, 0, 0, 0 } |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 92 | }; |
| 93 | |
Damien Miller | 690d989 | 2013-11-08 12:16:49 +1100 | [diff] [blame] | 94 | /* Returns a list of supported MACs separated by the specified char. */ |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 95 | char * |
Damien Miller | 690d989 | 2013-11-08 12:16:49 +1100 | [diff] [blame] | 96 | mac_alg_list(char sep) |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 97 | { |
| 98 | char *ret = NULL; |
| 99 | size_t nlen, rlen = 0; |
| 100 | const struct macalg *m; |
| 101 | |
| 102 | for (m = macs; m->name != NULL; m++) { |
| 103 | if (ret != NULL) |
Damien Miller | 690d989 | 2013-11-08 12:16:49 +1100 | [diff] [blame] | 104 | ret[rlen++] = sep; |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 105 | nlen = strlen(m->name); |
| 106 | ret = xrealloc(ret, 1, rlen + nlen + 2); |
| 107 | memcpy(ret + rlen, m->name, nlen + 1); |
| 108 | rlen += nlen; |
| 109 | } |
| 110 | return ret; |
| 111 | } |
| 112 | |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 113 | static void |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 114 | mac_setup_by_alg(Mac *mac, const struct macalg *macalg) |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 115 | { |
| 116 | int evp_len; |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 117 | |
| 118 | mac->type = macalg->type; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 119 | if (mac->type == SSH_EVP) { |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 120 | mac->evp_md = macalg->mdfunc(); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 121 | if ((evp_len = EVP_MD_size(mac->evp_md)) <= 0) |
| 122 | fatal("mac %s len %d", mac->name, evp_len); |
| 123 | mac->key_len = mac->mac_len = (u_int)evp_len; |
| 124 | } else { |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 125 | mac->mac_len = macalg->len / 8; |
| 126 | mac->key_len = macalg->key_len / 8; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 127 | mac->umac_ctx = NULL; |
| 128 | } |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 129 | if (macalg->truncatebits != 0) |
| 130 | mac->mac_len = macalg->truncatebits / 8; |
| 131 | mac->etm = macalg->etm; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 132 | } |
| 133 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 134 | int |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 135 | mac_setup(Mac *mac, char *name) |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 136 | { |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 137 | const struct macalg *m; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 138 | |
Damien Miller | ea11119 | 2013-04-23 19:24:32 +1000 | [diff] [blame] | 139 | for (m = macs; m->name != NULL; m++) { |
| 140 | if (strcmp(name, m->name) != 0) |
| 141 | continue; |
| 142 | if (mac != NULL) |
| 143 | mac_setup_by_alg(mac, m); |
| 144 | debug2("mac_setup: found %s", name); |
| 145 | return (0); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 146 | } |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 147 | debug2("mac_setup: unknown %s", name); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 148 | return (-1); |
| 149 | } |
| 150 | |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 151 | int |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 152 | mac_init(Mac *mac) |
| 153 | { |
| 154 | if (mac->key == NULL) |
| 155 | fatal("mac_init: no key"); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 156 | switch (mac->type) { |
| 157 | case SSH_EVP: |
| 158 | if (mac->evp_md == NULL) |
| 159 | return -1; |
Damien Miller | d0e582c | 2011-12-19 10:51:39 +1100 | [diff] [blame] | 160 | HMAC_CTX_init(&mac->evp_ctx); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 161 | HMAC_Init(&mac->evp_ctx, mac->key, mac->key_len, mac->evp_md); |
| 162 | return 0; |
| 163 | case SSH_UMAC: |
| 164 | mac->umac_ctx = umac_new(mac->key); |
| 165 | return 0; |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 166 | case SSH_UMAC128: |
| 167 | mac->umac_ctx = umac128_new(mac->key); |
| 168 | return 0; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 169 | default: |
| 170 | return -1; |
| 171 | } |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 172 | } |
| 173 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 174 | u_char * |
| 175 | mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen) |
| 176 | { |
Darren Tucker | 4ac66af | 2013-06-06 08:12:37 +1000 | [diff] [blame] | 177 | static union { |
| 178 | u_char m[EVP_MAX_MD_SIZE]; |
| 179 | u_int64_t for_align; |
| 180 | } u; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 181 | u_char b[4], nonce[8]; |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 182 | |
Darren Tucker | 4ac66af | 2013-06-06 08:12:37 +1000 | [diff] [blame] | 183 | if (mac->mac_len > sizeof(u)) |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 184 | fatal("mac_compute: mac too long %u %lu", |
Darren Tucker | 4ac66af | 2013-06-06 08:12:37 +1000 | [diff] [blame] | 185 | mac->mac_len, (u_long)sizeof(u)); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 186 | |
| 187 | switch (mac->type) { |
| 188 | case SSH_EVP: |
| 189 | put_u32(b, seqno); |
| 190 | /* reset HMAC context */ |
| 191 | HMAC_Init(&mac->evp_ctx, NULL, 0, NULL); |
| 192 | HMAC_Update(&mac->evp_ctx, b, sizeof(b)); |
| 193 | HMAC_Update(&mac->evp_ctx, data, datalen); |
Darren Tucker | 4ac66af | 2013-06-06 08:12:37 +1000 | [diff] [blame] | 194 | HMAC_Final(&mac->evp_ctx, u.m, NULL); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 195 | break; |
| 196 | case SSH_UMAC: |
| 197 | put_u64(nonce, seqno); |
| 198 | umac_update(mac->umac_ctx, data, datalen); |
Darren Tucker | 4ac66af | 2013-06-06 08:12:37 +1000 | [diff] [blame] | 199 | umac_final(mac->umac_ctx, u.m, nonce); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 200 | break; |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 201 | case SSH_UMAC128: |
| 202 | put_u64(nonce, seqno); |
| 203 | umac128_update(mac->umac_ctx, data, datalen); |
Darren Tucker | 4ac66af | 2013-06-06 08:12:37 +1000 | [diff] [blame] | 204 | umac128_final(mac->umac_ctx, u.m, nonce); |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 205 | break; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 206 | default: |
| 207 | fatal("mac_compute: unknown MAC type"); |
| 208 | } |
Darren Tucker | 4ac66af | 2013-06-06 08:12:37 +1000 | [diff] [blame] | 209 | return (u.m); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 210 | } |
| 211 | |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 212 | void |
| 213 | mac_clear(Mac *mac) |
| 214 | { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 215 | if (mac->type == SSH_UMAC) { |
| 216 | if (mac->umac_ctx != NULL) |
| 217 | umac_delete(mac->umac_ctx); |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 218 | } else if (mac->type == SSH_UMAC128) { |
| 219 | if (mac->umac_ctx != NULL) |
| 220 | umac128_delete(mac->umac_ctx); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 221 | } else if (mac->evp_md != NULL) |
| 222 | HMAC_cleanup(&mac->evp_ctx); |
| 223 | mac->evp_md = NULL; |
| 224 | mac->umac_ctx = NULL; |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 225 | } |
| 226 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 227 | /* XXX copied from ciphers_valid */ |
| 228 | #define MAC_SEP "," |
| 229 | int |
| 230 | mac_valid(const char *names) |
| 231 | { |
| 232 | char *maclist, *cp, *p; |
| 233 | |
| 234 | if (names == NULL || strcmp(names, "") == 0) |
| 235 | return (0); |
| 236 | maclist = cp = xstrdup(names); |
| 237 | for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0'; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 238 | (p = strsep(&cp, MAC_SEP))) { |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 239 | if (mac_setup(NULL, p) < 0) { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 240 | debug("bad mac %s [%s]", p, names); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 241 | free(maclist); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 242 | return (0); |
| 243 | } else { |
| 244 | debug3("mac ok: %s [%s]", p, names); |
| 245 | } |
| 246 | } |
| 247 | debug3("macs ok: [%s]", names); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 248 | free(maclist); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 249 | return (1); |
| 250 | } |