1 /* $OpenBSD: digest-libc.c,v 1.2 2014/02/02 03:44:31 djm Exp $ */ 2 /* 3 * Copyright (c) 2013 Damien Miller <djm@mindrot.org> 4 * Copyright (c) 2014 Markus Friedl. All rights reserved. 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/types.h> 20 #include <limits.h> 21 #include <stdlib.h> 22 #include <string.h> 23 24 #include <md5.h> 25 #include <rmd160.h> 26 #include <sha1.h> 27 #include <sha2.h> 28 29 #include "buffer.h" 30 #include "digest.h" 31 32 typedef void md_init_fn(void *mdctx); 33 typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen); 34 typedef void md_final_fn(u_int8_t[], void *mdctx); 35 36 struct ssh_digest_ctx { 37 int alg; 38 void *mdctx; 39 }; 40 41 struct ssh_digest { 42 int id; 43 const char *name; 44 size_t block_len; 45 size_t digest_len; 46 size_t ctx_len; 47 md_init_fn *md_init; 48 md_update_fn *md_update; 49 md_final_fn *md_final; 50 }; 51 52 /* NB. Indexed directly by algorithm number */ 53 const struct ssh_digest digests[SSH_DIGEST_MAX] = { 54 { 55 SSH_DIGEST_MD5, 56 "MD5", 57 MD5_BLOCK_LENGTH, 58 MD5_DIGEST_LENGTH, 59 sizeof(MD5_CTX), 60 (md_init_fn *) MD5Init, 61 (md_update_fn *) MD5Update, 62 (md_final_fn *) MD5Final 63 }, 64 { 65 SSH_DIGEST_RIPEMD160, 66 "RIPEMD160", 67 RMD160_BLOCK_LENGTH, 68 RMD160_DIGEST_LENGTH, 69 sizeof(RMD160_CTX), 70 (md_init_fn *) RMD160Init, 71 (md_update_fn *) RMD160Update, 72 (md_final_fn *) RMD160Final 73 }, 74 { 75 SSH_DIGEST_SHA1, 76 "SHA1", 77 SHA1_BLOCK_LENGTH, 78 SHA1_DIGEST_LENGTH, 79 sizeof(SHA1_CTX), 80 (md_init_fn *) SHA1Init, 81 (md_update_fn *) SHA1Update, 82 (md_final_fn *) SHA1Final 83 }, 84 { 85 SSH_DIGEST_SHA256, 86 "SHA256", 87 SHA256_BLOCK_LENGTH, 88 SHA256_DIGEST_LENGTH, 89 sizeof(SHA2_CTX), 90 (md_init_fn *) SHA256Init, 91 (md_update_fn *) SHA256Update, 92 (md_final_fn *) SHA256Final 93 }, 94 { 95 SSH_DIGEST_SHA384, 96 "SHA384", 97 SHA384_BLOCK_LENGTH, 98 SHA384_DIGEST_LENGTH, 99 sizeof(SHA2_CTX), 100 (md_init_fn *) SHA384Init, 101 (md_update_fn *) SHA384Update, 102 (md_final_fn *) SHA384Final 103 }, 104 { 105 SSH_DIGEST_SHA512, 106 "SHA512", 107 SHA512_BLOCK_LENGTH, 108 SHA512_DIGEST_LENGTH, 109 sizeof(SHA2_CTX), 110 (md_init_fn *) SHA512Init, 111 (md_update_fn *) SHA512Update, 112 (md_final_fn *) SHA512Final 113 } 114 }; 115 116 static const struct ssh_digest * 117 ssh_digest_by_alg(int alg) 118 { 119 if (alg < 0 || alg >= SSH_DIGEST_MAX) 120 return NULL; 121 if (digests[alg].id != alg) /* sanity */ 122 return NULL; 123 return &(digests[alg]); 124 } 125 126 size_t 127 ssh_digest_bytes(int alg) 128 { 129 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 130 131 return digest == NULL ? 0 : digest->digest_len; 132 } 133 134 size_t 135 ssh_digest_blocksize(struct ssh_digest_ctx *ctx) 136 { 137 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 138 139 return digest == NULL ? 0 : digest->block_len; 140 } 141 142 struct ssh_digest_ctx * 143 ssh_digest_start(int alg) 144 { 145 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 146 struct ssh_digest_ctx *ret; 147 148 if (digest == NULL || (ret = calloc(1, sizeof(ret))) == NULL) 149 return NULL; 150 if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) { 151 free(ret); 152 return NULL; 153 } 154 ret->alg = alg; 155 digest->md_init(ret->mdctx); 156 return ret; 157 } 158 159 int 160 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to) 161 { 162 const struct ssh_digest *digest = ssh_digest_by_alg(from->alg); 163 164 if (digest == NULL || from->alg != to->alg) 165 return -1; 166 memcpy(to->mdctx, from->mdctx, digest->ctx_len); 167 return 0; 168 } 169 170 int 171 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) 172 { 173 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 174 175 if (digest == NULL) 176 return -1; 177 digest->md_update(ctx->mdctx, m, mlen); 178 return 0; 179 } 180 181 int 182 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const Buffer *b) 183 { 184 return ssh_digest_update(ctx, buffer_ptr(b), buffer_len(b)); 185 } 186 187 int 188 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) 189 { 190 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 191 192 if (digest == NULL) 193 return -1; 194 if (dlen > UINT_MAX) 195 return -1; 196 if (dlen < digest->digest_len) /* No truncation allowed */ 197 return -1; 198 digest->md_final(d, ctx->mdctx); 199 return 0; 200 } 201 202 void 203 ssh_digest_free(struct ssh_digest_ctx *ctx) 204 { 205 const struct ssh_digest *digest; 206 207 if (ctx != NULL) { 208 digest = ssh_digest_by_alg(ctx->alg); 209 if (digest) { 210 explicit_bzero(ctx->mdctx, digest->ctx_len); 211 free(ctx->mdctx); 212 explicit_bzero(ctx, sizeof(*ctx)); 213 free(ctx); 214 } 215 } 216 } 217 218 int 219 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) 220 { 221 struct ssh_digest_ctx *ctx = ssh_digest_start(alg); 222 223 if (ctx == NULL) 224 return -1; 225 if (ssh_digest_update(ctx, m, mlen) != 0 || 226 ssh_digest_final(ctx, d, dlen) != 0) 227 return -1; 228 ssh_digest_free(ctx); 229 return 0; 230 } 231 232 int 233 ssh_digest_buffer(int alg, const Buffer *b, u_char *d, size_t dlen) 234 { 235 return ssh_digest_memory(alg, buffer_ptr(b), buffer_len(b), d, dlen); 236 } 237