Damien Miller | d0e582c | 2011-12-19 10:51:39 +1100 | [diff] [blame^] | 1 | /* $OpenBSD: mac.c,v 1.17 2011/12/02 00:43:57 djm 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 | |
| 47 | #define SSH_EVP 1 /* OpenSSL EVP-based MAC */ |
| 48 | #define SSH_UMAC 2 /* UMAC (not integrated with OpenSSL) */ |
| 49 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 50 | struct { |
| 51 | char *name; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 52 | int type; |
Ben Lindstrom | 6a24641 | 2002-06-06 19:48:16 +0000 | [diff] [blame] | 53 | const EVP_MD * (*mdfunc)(void); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 54 | int truncatebits; /* truncate digest if != 0 */ |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 55 | int key_len; /* just for UMAC */ |
| 56 | int len; /* just for UMAC */ |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 57 | } macs[] = { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 58 | { "hmac-sha1", SSH_EVP, EVP_sha1, 0, -1, -1 }, |
| 59 | { "hmac-sha1-96", SSH_EVP, EVP_sha1, 96, -1, -1 }, |
Tim Rice | a122682 | 2011-08-16 17:29:01 -0700 | [diff] [blame] | 60 | #ifdef HAVE_EVP_SHA256 |
Damien Miller | 20bd453 | 2011-08-06 06:17:30 +1000 | [diff] [blame] | 61 | { "hmac-sha2-256", SSH_EVP, EVP_sha256, 0, -1, -1 }, |
| 62 | { "hmac-sha2-256-96", SSH_EVP, EVP_sha256, 96, -1, -1 }, |
| 63 | { "hmac-sha2-512", SSH_EVP, EVP_sha512, 0, -1, -1 }, |
| 64 | { "hmac-sha2-512-96", SSH_EVP, EVP_sha512, 96, -1, -1 }, |
Tim Rice | a122682 | 2011-08-16 17:29:01 -0700 | [diff] [blame] | 65 | #endif |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 66 | { "hmac-md5", SSH_EVP, EVP_md5, 0, -1, -1 }, |
| 67 | { "hmac-md5-96", SSH_EVP, EVP_md5, 96, -1, -1 }, |
| 68 | { "hmac-ripemd160", SSH_EVP, EVP_ripemd160, 0, -1, -1 }, |
| 69 | { "hmac-ripemd160@openssh.com", SSH_EVP, EVP_ripemd160, 0, -1, -1 }, |
| 70 | { "umac-64@openssh.com", SSH_UMAC, NULL, 0, 128, 64 }, |
| 71 | { NULL, 0, NULL, 0, -1, -1 } |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 72 | }; |
| 73 | |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 74 | static void |
| 75 | mac_setup_by_id(Mac *mac, int which) |
| 76 | { |
| 77 | int evp_len; |
| 78 | mac->type = macs[which].type; |
| 79 | if (mac->type == SSH_EVP) { |
| 80 | mac->evp_md = (*macs[which].mdfunc)(); |
| 81 | if ((evp_len = EVP_MD_size(mac->evp_md)) <= 0) |
| 82 | fatal("mac %s len %d", mac->name, evp_len); |
| 83 | mac->key_len = mac->mac_len = (u_int)evp_len; |
| 84 | } else { |
| 85 | mac->mac_len = macs[which].len / 8; |
| 86 | mac->key_len = macs[which].key_len / 8; |
| 87 | mac->umac_ctx = NULL; |
| 88 | } |
| 89 | if (macs[which].truncatebits != 0) |
| 90 | mac->mac_len = macs[which].truncatebits / 8; |
| 91 | } |
| 92 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 93 | int |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 94 | mac_setup(Mac *mac, char *name) |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 95 | { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 96 | int i; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 97 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 98 | for (i = 0; macs[i].name; i++) { |
| 99 | if (strcmp(name, macs[i].name) == 0) { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 100 | if (mac != NULL) |
| 101 | mac_setup_by_id(mac, i); |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 102 | debug2("mac_setup: found %s", name); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 103 | return (0); |
| 104 | } |
| 105 | } |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 106 | debug2("mac_setup: unknown %s", name); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 107 | return (-1); |
| 108 | } |
| 109 | |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 110 | int |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 111 | mac_init(Mac *mac) |
| 112 | { |
| 113 | if (mac->key == NULL) |
| 114 | fatal("mac_init: no key"); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 115 | switch (mac->type) { |
| 116 | case SSH_EVP: |
| 117 | if (mac->evp_md == NULL) |
| 118 | return -1; |
Damien Miller | d0e582c | 2011-12-19 10:51:39 +1100 | [diff] [blame^] | 119 | HMAC_CTX_init(&mac->evp_ctx); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 120 | HMAC_Init(&mac->evp_ctx, mac->key, mac->key_len, mac->evp_md); |
| 121 | return 0; |
| 122 | case SSH_UMAC: |
| 123 | mac->umac_ctx = umac_new(mac->key); |
| 124 | return 0; |
| 125 | default: |
| 126 | return -1; |
| 127 | } |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 128 | } |
| 129 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 130 | u_char * |
| 131 | mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen) |
| 132 | { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 133 | static u_char m[EVP_MAX_MD_SIZE]; |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 134 | u_char b[4], nonce[8]; |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 135 | |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 136 | if (mac->mac_len > sizeof(m)) |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 137 | fatal("mac_compute: mac too long %u %lu", |
Darren Tucker | c7e030f | 2008-06-13 10:58:50 +1000 | [diff] [blame] | 138 | mac->mac_len, (u_long)sizeof(m)); |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 139 | |
| 140 | switch (mac->type) { |
| 141 | case SSH_EVP: |
| 142 | put_u32(b, seqno); |
| 143 | /* reset HMAC context */ |
| 144 | HMAC_Init(&mac->evp_ctx, NULL, 0, NULL); |
| 145 | HMAC_Update(&mac->evp_ctx, b, sizeof(b)); |
| 146 | HMAC_Update(&mac->evp_ctx, data, datalen); |
| 147 | HMAC_Final(&mac->evp_ctx, m, NULL); |
| 148 | break; |
| 149 | case SSH_UMAC: |
| 150 | put_u64(nonce, seqno); |
| 151 | umac_update(mac->umac_ctx, data, datalen); |
| 152 | umac_final(mac->umac_ctx, m, nonce); |
| 153 | break; |
| 154 | default: |
| 155 | fatal("mac_compute: unknown MAC type"); |
| 156 | } |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 157 | return (m); |
| 158 | } |
| 159 | |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 160 | void |
| 161 | mac_clear(Mac *mac) |
| 162 | { |
Damien Miller | e45796f | 2007-06-11 14:01:42 +1000 | [diff] [blame] | 163 | if (mac->type == SSH_UMAC) { |
| 164 | if (mac->umac_ctx != NULL) |
| 165 | umac_delete(mac->umac_ctx); |
| 166 | } else if (mac->evp_md != NULL) |
| 167 | HMAC_cleanup(&mac->evp_ctx); |
| 168 | mac->evp_md = NULL; |
| 169 | mac->umac_ctx = NULL; |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 170 | } |
| 171 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 172 | /* XXX copied from ciphers_valid */ |
| 173 | #define MAC_SEP "," |
| 174 | int |
| 175 | mac_valid(const char *names) |
| 176 | { |
| 177 | char *maclist, *cp, *p; |
| 178 | |
| 179 | if (names == NULL || strcmp(names, "") == 0) |
| 180 | return (0); |
| 181 | maclist = cp = xstrdup(names); |
| 182 | for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0'; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 183 | (p = strsep(&cp, MAC_SEP))) { |
Darren Tucker | 5f3d5be | 2007-06-05 18:30:18 +1000 | [diff] [blame] | 184 | if (mac_setup(NULL, p) < 0) { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 185 | debug("bad mac %s [%s]", p, names); |
| 186 | xfree(maclist); |
| 187 | return (0); |
| 188 | } else { |
| 189 | debug3("mac ok: %s [%s]", p, names); |
| 190 | } |
| 191 | } |
| 192 | debug3("macs ok: [%s]", names); |
| 193 | xfree(maclist); |
| 194 | return (1); |
| 195 | } |