1 /* $OpenBSD: digest-libc.c,v 1.3 2014/06/24 01:13:21 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 "ssherr.h" 30 #include "sshbuf.h" 31 #include "digest.h" 32 33 typedef void md_init_fn(void *mdctx); 34 typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen); 35 typedef void md_final_fn(u_int8_t[], void *mdctx); 36 37 struct ssh_digest_ctx { 38 int alg; 39 void *mdctx; 40 }; 41 42 struct ssh_digest { 43 int id; 44 const char *name; 45 size_t block_len; 46 size_t digest_len; 47 size_t ctx_len; 48 md_init_fn *md_init; 49 md_update_fn *md_update; 50 md_final_fn *md_final; 51 }; 52 53 /* NB. Indexed directly by algorithm number */ 54 const struct ssh_digest digests[SSH_DIGEST_MAX] = { 55 { 56 SSH_DIGEST_MD5, 57 "MD5", 58 MD5_BLOCK_LENGTH, 59 MD5_DIGEST_LENGTH, 60 sizeof(MD5_CTX), 61 (md_init_fn *) MD5Init, 62 (md_update_fn *) MD5Update, 63 (md_final_fn *) MD5Final 64 }, 65 { 66 SSH_DIGEST_RIPEMD160, 67 "RIPEMD160", 68 RMD160_BLOCK_LENGTH, 69 RMD160_DIGEST_LENGTH, 70 sizeof(RMD160_CTX), 71 (md_init_fn *) RMD160Init, 72 (md_update_fn *) RMD160Update, 73 (md_final_fn *) RMD160Final 74 }, 75 { 76 SSH_DIGEST_SHA1, 77 "SHA1", 78 SHA1_BLOCK_LENGTH, 79 SHA1_DIGEST_LENGTH, 80 sizeof(SHA1_CTX), 81 (md_init_fn *) SHA1Init, 82 (md_update_fn *) SHA1Update, 83 (md_final_fn *) SHA1Final 84 }, 85 { 86 SSH_DIGEST_SHA256, 87 "SHA256", 88 SHA256_BLOCK_LENGTH, 89 SHA256_DIGEST_LENGTH, 90 sizeof(SHA2_CTX), 91 (md_init_fn *) SHA256Init, 92 (md_update_fn *) SHA256Update, 93 (md_final_fn *) SHA256Final 94 }, 95 { 96 SSH_DIGEST_SHA384, 97 "SHA384", 98 SHA384_BLOCK_LENGTH, 99 SHA384_DIGEST_LENGTH, 100 sizeof(SHA2_CTX), 101 (md_init_fn *) SHA384Init, 102 (md_update_fn *) SHA384Update, 103 (md_final_fn *) SHA384Final 104 }, 105 { 106 SSH_DIGEST_SHA512, 107 "SHA512", 108 SHA512_BLOCK_LENGTH, 109 SHA512_DIGEST_LENGTH, 110 sizeof(SHA2_CTX), 111 (md_init_fn *) SHA512Init, 112 (md_update_fn *) SHA512Update, 113 (md_final_fn *) SHA512Final 114 } 115 }; 116 117 static const struct ssh_digest * 118 ssh_digest_by_alg(int alg) 119 { 120 if (alg < 0 || alg >= SSH_DIGEST_MAX) 121 return NULL; 122 if (digests[alg].id != alg) /* sanity */ 123 return NULL; 124 return &(digests[alg]); 125 } 126 127 size_t 128 ssh_digest_bytes(int alg) 129 { 130 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 131 132 return digest == NULL ? 0 : digest->digest_len; 133 } 134 135 size_t 136 ssh_digest_blocksize(struct ssh_digest_ctx *ctx) 137 { 138 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 139 140 return digest == NULL ? 0 : digest->block_len; 141 } 142 143 struct ssh_digest_ctx * 144 ssh_digest_start(int alg) 145 { 146 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 147 struct ssh_digest_ctx *ret; 148 149 if (digest == NULL || (ret = calloc(1, sizeof(ret))) == NULL) 150 return NULL; 151 if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) { 152 free(ret); 153 return NULL; 154 } 155 ret->alg = alg; 156 digest->md_init(ret->mdctx); 157 return ret; 158 } 159 160 int 161 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to) 162 { 163 const struct ssh_digest *digest = ssh_digest_by_alg(from->alg); 164 165 if (digest == NULL || from->alg != to->alg) 166 return SSH_ERR_INVALID_ARGUMENT; 167 memcpy(to->mdctx, from->mdctx, digest->ctx_len); 168 return 0; 169 } 170 171 int 172 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) 173 { 174 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 175 176 if (digest == NULL) 177 return SSH_ERR_INVALID_ARGUMENT; 178 digest->md_update(ctx->mdctx, m, mlen); 179 return 0; 180 } 181 182 int 183 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b) 184 { 185 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b)); 186 } 187 188 int 189 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) 190 { 191 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 192 193 if (digest == NULL) 194 return SSH_ERR_INVALID_ARGUMENT; 195 if (dlen > UINT_MAX) 196 return SSH_ERR_INVALID_ARGUMENT; 197 if (dlen < digest->digest_len) /* No truncation allowed */ 198 return SSH_ERR_INVALID_ARGUMENT; 199 digest->md_final(d, ctx->mdctx); 200 return 0; 201 } 202 203 void 204 ssh_digest_free(struct ssh_digest_ctx *ctx) 205 { 206 const struct ssh_digest *digest; 207 208 if (ctx != NULL) { 209 digest = ssh_digest_by_alg(ctx->alg); 210 if (digest) { 211 explicit_bzero(ctx->mdctx, digest->ctx_len); 212 free(ctx->mdctx); 213 explicit_bzero(ctx, sizeof(*ctx)); 214 free(ctx); 215 } 216 } 217 } 218 219 int 220 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) 221 { 222 struct ssh_digest_ctx *ctx = ssh_digest_start(alg); 223 224 if (ctx == NULL) 225 return SSH_ERR_INVALID_ARGUMENT; 226 if (ssh_digest_update(ctx, m, mlen) != 0 || 227 ssh_digest_final(ctx, d, dlen) != 0) 228 return SSH_ERR_INVALID_ARGUMENT; 229 ssh_digest_free(ctx); 230 return 0; 231 } 232 233 int 234 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen) 235 { 236 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen); 237 } 238