Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 1 | /* $OpenBSD: mac.c,v 1.19 2012/10/04 13:21:50 markus 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 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 53 | struct { |
| 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 */ |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 60 | } macs[] = { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 61 | { "hmac-sha1", SSH_EVP, EVP_sha1, 0, -1, -1 }, |
| 62 | { "hmac-sha1-96", SSH_EVP, EVP_sha1, 96, -1, -1 }, |
Tim Rice | a122682 | 2011-08-16 17:29:01 -0700 | [diff] [blame] | 63 | #ifdef HAVE_EVP_SHA256 |
Damien Miller | 20bd453 | 2011-08-06 06:17:30 +1000 | [diff] [blame] | 64 | { "hmac-sha2-256", SSH_EVP, EVP_sha256, 0, -1, -1 }, |
Damien Miller | 20bd453 | 2011-08-06 06:17:30 +1000 | [diff] [blame] | 65 | { "hmac-sha2-512", SSH_EVP, EVP_sha512, 0, -1, -1 }, |
Tim Rice | a122682 | 2011-08-16 17:29:01 -0700 | [diff] [blame] | 66 | #endif |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 67 | { "hmac-md5", SSH_EVP, EVP_md5, 0, -1, -1 }, |
| 68 | { "hmac-md5-96", SSH_EVP, EVP_md5, 96, -1, -1 }, |
| 69 | { "hmac-ripemd160", SSH_EVP, EVP_ripemd160, 0, -1, -1 }, |
| 70 | { "hmac-ripemd160@openssh.com", SSH_EVP, EVP_ripemd160, 0, -1, -1 }, |
| 71 | { "umac-64@openssh.com", SSH_UMAC, NULL, 0, 128, 64 }, |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 72 | { "umac-128@openssh.com", SSH_UMAC128, NULL, 0, 128, 128 }, |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 73 | { NULL, 0, NULL, 0, -1, -1 } |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 74 | }; |
| 75 | |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 76 | static void |
| 77 | mac_setup_by_id(Mac *mac, int which) |
| 78 | { |
| 79 | int evp_len; |
| 80 | mac->type = macs[which].type; |
| 81 | if (mac->type == SSH_EVP) { |
| 82 | mac->evp_md = (*macs[which].mdfunc)(); |
| 83 | if ((evp_len = EVP_MD_size(mac->evp_md)) <= 0) |
| 84 | fatal("mac %s len %d", mac->name, evp_len); |
| 85 | mac->key_len = mac->mac_len = (u_int)evp_len; |
| 86 | } else { |
| 87 | mac->mac_len = macs[which].len / 8; |
| 88 | mac->key_len = macs[which].key_len / 8; |
| 89 | mac->umac_ctx = NULL; |
| 90 | } |
| 91 | if (macs[which].truncatebits != 0) |
| 92 | mac->mac_len = macs[which].truncatebits / 8; |
| 93 | } |
| 94 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 95 | int |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 96 | mac_setup(Mac *mac, char *name) |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 97 | { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 98 | int i; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 99 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 100 | for (i = 0; macs[i].name; i++) { |
| 101 | if (strcmp(name, macs[i].name) == 0) { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 102 | if (mac != NULL) |
| 103 | mac_setup_by_id(mac, i); |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 104 | debug2("mac_setup: found %s", name); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 105 | return (0); |
| 106 | } |
| 107 | } |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 108 | debug2("mac_setup: unknown %s", name); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 109 | return (-1); |
| 110 | } |
| 111 | |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 112 | int |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 113 | mac_init(Mac *mac) |
| 114 | { |
| 115 | if (mac->key == NULL) |
| 116 | fatal("mac_init: no key"); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 117 | switch (mac->type) { |
| 118 | case SSH_EVP: |
| 119 | if (mac->evp_md == NULL) |
| 120 | return -1; |
Damien Miller | d0e582c | 2011-12-19 10:51:39 +1100 | [diff] [blame] | 121 | HMAC_CTX_init(&mac->evp_ctx); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 122 | HMAC_Init(&mac->evp_ctx, mac->key, mac->key_len, mac->evp_md); |
| 123 | return 0; |
| 124 | case SSH_UMAC: |
| 125 | mac->umac_ctx = umac_new(mac->key); |
| 126 | return 0; |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 127 | case SSH_UMAC128: |
| 128 | mac->umac_ctx = umac128_new(mac->key); |
| 129 | return 0; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 130 | default: |
| 131 | return -1; |
| 132 | } |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 133 | } |
| 134 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 135 | u_char * |
| 136 | mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen) |
| 137 | { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 138 | static u_char m[EVP_MAX_MD_SIZE]; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 139 | u_char b[4], nonce[8]; |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 140 | |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 141 | if (mac->mac_len > sizeof(m)) |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 142 | fatal("mac_compute: mac too long %u %lu", |
Darren Tucker | c7e030f | 2008-06-13 10:58:50 +1000 | [diff] [blame] | 143 | mac->mac_len, (u_long)sizeof(m)); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 144 | |
| 145 | switch (mac->type) { |
| 146 | case SSH_EVP: |
| 147 | put_u32(b, seqno); |
| 148 | /* reset HMAC context */ |
| 149 | HMAC_Init(&mac->evp_ctx, NULL, 0, NULL); |
| 150 | HMAC_Update(&mac->evp_ctx, b, sizeof(b)); |
| 151 | HMAC_Update(&mac->evp_ctx, data, datalen); |
| 152 | HMAC_Final(&mac->evp_ctx, m, NULL); |
| 153 | break; |
| 154 | case SSH_UMAC: |
| 155 | put_u64(nonce, seqno); |
| 156 | umac_update(mac->umac_ctx, data, datalen); |
| 157 | umac_final(mac->umac_ctx, m, nonce); |
| 158 | break; |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 159 | case SSH_UMAC128: |
| 160 | put_u64(nonce, seqno); |
| 161 | umac128_update(mac->umac_ctx, data, datalen); |
| 162 | umac128_final(mac->umac_ctx, m, nonce); |
| 163 | break; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 164 | default: |
| 165 | fatal("mac_compute: unknown MAC type"); |
| 166 | } |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 167 | return (m); |
| 168 | } |
| 169 | |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 170 | void |
| 171 | mac_clear(Mac *mac) |
| 172 | { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 173 | if (mac->type == SSH_UMAC) { |
| 174 | if (mac->umac_ctx != NULL) |
| 175 | umac_delete(mac->umac_ctx); |
Darren Tucker | 427e409 | 2012-10-05 11:02:39 +1000 | [diff] [blame] | 176 | } else if (mac->type == SSH_UMAC128) { |
| 177 | if (mac->umac_ctx != NULL) |
| 178 | umac128_delete(mac->umac_ctx); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 179 | } else if (mac->evp_md != NULL) |
| 180 | HMAC_cleanup(&mac->evp_ctx); |
| 181 | mac->evp_md = NULL; |
| 182 | mac->umac_ctx = NULL; |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 183 | } |
| 184 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 185 | /* XXX copied from ciphers_valid */ |
| 186 | #define MAC_SEP "," |
| 187 | int |
| 188 | mac_valid(const char *names) |
| 189 | { |
| 190 | char *maclist, *cp, *p; |
| 191 | |
| 192 | if (names == NULL || strcmp(names, "") == 0) |
| 193 | return (0); |
| 194 | maclist = cp = xstrdup(names); |
| 195 | for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0'; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 196 | (p = strsep(&cp, MAC_SEP))) { |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 197 | if (mac_setup(NULL, p) < 0) { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 198 | debug("bad mac %s [%s]", p, names); |
| 199 | xfree(maclist); |
| 200 | return (0); |
| 201 | } else { |
| 202 | debug3("mac ok: %s [%s]", p, names); |
| 203 | } |
| 204 | } |
| 205 | debug3("macs ok: [%s]", names); |
| 206 | xfree(maclist); |
| 207 | return (1); |
| 208 | } |