markus@openbsd.org | df100be | 2015-03-24 20:03:44 +0000 | [diff] [blame] | 1 | /* $OpenBSD: hmac.c,v 1.12 2015/03/24 20:03:44 markus Exp $ */ |
Damien Miller | 4e8d937 | 2014-02-04 11:02:42 +1100 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2014 Markus Friedl. All rights reserved. |
| 4 | * |
| 5 | * Permission to use, copy, modify, and distribute this software for any |
| 6 | * purpose with or without fee is hereby granted, provided that the above |
| 7 | * copyright notice and this permission notice appear in all copies. |
| 8 | * |
| 9 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| 12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| 15 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 16 | */ |
| 17 | |
| 18 | #include "includes.h" |
| 19 | |
| 20 | #include <sys/types.h> |
Darren Tucker | 2ea6031 | 2019-07-23 22:11:50 +1000 | [diff] [blame] | 21 | |
| 22 | #include <stdlib.h> |
Damien Miller | 4e8d937 | 2014-02-04 11:02:42 +1100 | [diff] [blame] | 23 | #include <string.h> |
| 24 | |
markus@openbsd.org | e17ac01 | 2015-01-15 21:37:14 +0000 | [diff] [blame] | 25 | #include "sshbuf.h" |
Damien Miller | 4e8d937 | 2014-02-04 11:02:42 +1100 | [diff] [blame] | 26 | #include "digest.h" |
| 27 | #include "hmac.h" |
| 28 | |
| 29 | struct ssh_hmac_ctx { |
| 30 | int alg; |
| 31 | struct ssh_digest_ctx *ictx; |
| 32 | struct ssh_digest_ctx *octx; |
| 33 | struct ssh_digest_ctx *digest; |
| 34 | u_char *buf; |
| 35 | size_t buf_len; |
| 36 | }; |
| 37 | |
| 38 | size_t |
| 39 | ssh_hmac_bytes(int alg) |
| 40 | { |
| 41 | return ssh_digest_bytes(alg); |
| 42 | } |
| 43 | |
| 44 | struct ssh_hmac_ctx * |
| 45 | ssh_hmac_start(int alg) |
| 46 | { |
| 47 | struct ssh_hmac_ctx *ret; |
| 48 | |
| 49 | if ((ret = calloc(1, sizeof(*ret))) == NULL) |
| 50 | return NULL; |
| 51 | ret->alg = alg; |
| 52 | if ((ret->ictx = ssh_digest_start(alg)) == NULL || |
| 53 | (ret->octx = ssh_digest_start(alg)) == NULL || |
| 54 | (ret->digest = ssh_digest_start(alg)) == NULL) |
| 55 | goto fail; |
| 56 | ret->buf_len = ssh_digest_blocksize(ret->ictx); |
| 57 | if ((ret->buf = calloc(1, ret->buf_len)) == NULL) |
| 58 | goto fail; |
| 59 | return ret; |
| 60 | fail: |
| 61 | ssh_hmac_free(ret); |
| 62 | return NULL; |
| 63 | } |
| 64 | |
| 65 | int |
| 66 | ssh_hmac_init(struct ssh_hmac_ctx *ctx, const void *key, size_t klen) |
| 67 | { |
| 68 | size_t i; |
| 69 | |
| 70 | /* reset ictx and octx if no is key given */ |
| 71 | if (key != NULL) { |
| 72 | /* truncate long keys */ |
| 73 | if (klen <= ctx->buf_len) |
| 74 | memcpy(ctx->buf, key, klen); |
| 75 | else if (ssh_digest_memory(ctx->alg, key, klen, ctx->buf, |
| 76 | ctx->buf_len) < 0) |
| 77 | return -1; |
| 78 | for (i = 0; i < ctx->buf_len; i++) |
| 79 | ctx->buf[i] ^= 0x36; |
| 80 | if (ssh_digest_update(ctx->ictx, ctx->buf, ctx->buf_len) < 0) |
| 81 | return -1; |
| 82 | for (i = 0; i < ctx->buf_len; i++) |
| 83 | ctx->buf[i] ^= 0x36 ^ 0x5c; |
| 84 | if (ssh_digest_update(ctx->octx, ctx->buf, ctx->buf_len) < 0) |
| 85 | return -1; |
| 86 | explicit_bzero(ctx->buf, ctx->buf_len); |
| 87 | } |
| 88 | /* start with ictx */ |
| 89 | if (ssh_digest_copy_state(ctx->ictx, ctx->digest) < 0) |
| 90 | return -1; |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | int |
| 95 | ssh_hmac_update(struct ssh_hmac_ctx *ctx, const void *m, size_t mlen) |
| 96 | { |
| 97 | return ssh_digest_update(ctx->digest, m, mlen); |
| 98 | } |
| 99 | |
| 100 | int |
markus@openbsd.org | e17ac01 | 2015-01-15 21:37:14 +0000 | [diff] [blame] | 101 | ssh_hmac_update_buffer(struct ssh_hmac_ctx *ctx, const struct sshbuf *b) |
Damien Miller | 4e8d937 | 2014-02-04 11:02:42 +1100 | [diff] [blame] | 102 | { |
| 103 | return ssh_digest_update_buffer(ctx->digest, b); |
| 104 | } |
| 105 | |
| 106 | int |
| 107 | ssh_hmac_final(struct ssh_hmac_ctx *ctx, u_char *d, size_t dlen) |
| 108 | { |
| 109 | size_t len; |
| 110 | |
| 111 | len = ssh_digest_bytes(ctx->alg); |
| 112 | if (dlen < len || |
| 113 | ssh_digest_final(ctx->digest, ctx->buf, len)) |
| 114 | return -1; |
| 115 | /* switch to octx */ |
| 116 | if (ssh_digest_copy_state(ctx->octx, ctx->digest) < 0 || |
| 117 | ssh_digest_update(ctx->digest, ctx->buf, len) < 0 || |
| 118 | ssh_digest_final(ctx->digest, d, dlen) < 0) |
| 119 | return -1; |
| 120 | return 0; |
| 121 | } |
| 122 | |
| 123 | void |
| 124 | ssh_hmac_free(struct ssh_hmac_ctx *ctx) |
| 125 | { |
| 126 | if (ctx != NULL) { |
| 127 | ssh_digest_free(ctx->ictx); |
| 128 | ssh_digest_free(ctx->octx); |
| 129 | ssh_digest_free(ctx->digest); |
| 130 | if (ctx->buf) { |
| 131 | explicit_bzero(ctx->buf, ctx->buf_len); |
| 132 | free(ctx->buf); |
| 133 | } |
| 134 | explicit_bzero(ctx, sizeof(*ctx)); |
| 135 | free(ctx); |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | #ifdef TEST |
| 140 | |
| 141 | /* cc -DTEST hmac.c digest.c buffer.c cleanup.c fatal.c log.c xmalloc.c -lcrypto */ |
| 142 | static void |
| 143 | hmac_test(void *key, size_t klen, void *m, size_t mlen, u_char *e, size_t elen) |
| 144 | { |
| 145 | struct ssh_hmac_ctx *ctx; |
| 146 | size_t i; |
| 147 | u_char digest[16]; |
| 148 | |
| 149 | if ((ctx = ssh_hmac_start(SSH_DIGEST_MD5)) == NULL) |
| 150 | printf("ssh_hmac_start failed"); |
| 151 | if (ssh_hmac_init(ctx, key, klen) < 0 || |
| 152 | ssh_hmac_update(ctx, m, mlen) < 0 || |
| 153 | ssh_hmac_final(ctx, digest, sizeof(digest)) < 0) |
| 154 | printf("ssh_hmac_xxx failed"); |
| 155 | ssh_hmac_free(ctx); |
| 156 | |
| 157 | if (memcmp(e, digest, elen)) { |
| 158 | for (i = 0; i < elen; i++) |
markus@openbsd.org | df100be | 2015-03-24 20:03:44 +0000 | [diff] [blame] | 159 | printf("[%zu] %2.2x %2.2x\n", i, e[i], digest[i]); |
Damien Miller | 4e8d937 | 2014-02-04 11:02:42 +1100 | [diff] [blame] | 160 | printf("mismatch\n"); |
| 161 | } else |
| 162 | printf("ok\n"); |
| 163 | } |
| 164 | |
| 165 | int |
| 166 | main(int argc, char **argv) |
| 167 | { |
| 168 | /* try test vectors from RFC 2104 */ |
| 169 | |
| 170 | u_char key1[16] = { |
| 171 | 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, |
| 172 | 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb }; |
| 173 | u_char *data1 = "Hi There"; |
| 174 | u_char dig1[16] = { |
| 175 | 0x92, 0x94, 0x72, 0x7a, 0x36, 0x38, 0xbb, 0x1c, |
| 176 | 0x13, 0xf4, 0x8e, 0xf8, 0x15, 0x8b, 0xfc, 0x9d }; |
| 177 | |
| 178 | u_char *key2 = "Jefe"; |
| 179 | u_char *data2 = "what do ya want for nothing?"; |
| 180 | u_char dig2[16] = { |
| 181 | 0x75, 0x0c, 0x78, 0x3e, 0x6a, 0xb0, 0xb5, 0x03, |
| 182 | 0xea, 0xa8, 0x6e, 0x31, 0x0a, 0x5d, 0xb7, 0x38 }; |
| 183 | |
| 184 | u_char key3[16]; |
| 185 | u_char data3[50]; |
| 186 | u_char dig3[16] = { |
| 187 | 0x56, 0xbe, 0x34, 0x52, 0x1d, 0x14, 0x4c, 0x88, |
| 188 | 0xdb, 0xb8, 0xc7, 0x33, 0xf0, 0xe8, 0xb3, 0xf6 }; |
| 189 | memset(key3, 0xaa, sizeof(key3)); |
| 190 | memset(data3, 0xdd, sizeof(data3)); |
| 191 | |
| 192 | hmac_test(key1, sizeof(key1), data1, strlen(data1), dig1, sizeof(dig1)); |
| 193 | hmac_test(key2, strlen(key2), data2, strlen(data2), dig2, sizeof(dig2)); |
| 194 | hmac_test(key3, sizeof(key3), data3, sizeof(data3), dig3, sizeof(dig3)); |
| 195 | |
| 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | #endif |