1 /* $OpenBSD: digest-libc.c,v 1.7 2020/02/26 13:40:09 jsg 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 #include "includes.h" 19 __RCSID("$NetBSD: digest-libc.c,v 1.8 2020/05/28 17:05:49 christos Exp $"); 20 21 #include <sys/types.h> 22 #include <limits.h> 23 #include <stdlib.h> 24 #include <string.h> 25 26 #include <md5.h> 27 #include <rmd160.h> 28 #include <sha1.h> 29 #include <sha2.h> 30 31 #include "ssherr.h" 32 #include "sshbuf.h" 33 #include "digest.h" 34 35 typedef void md_init_fn(void *mdctx); 36 typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen); 37 typedef void md_final_fn(u_int8_t[], void *mdctx); 38 39 struct ssh_digest_ctx { 40 int alg; 41 void *mdctx; 42 }; 43 44 struct ssh_digest { 45 int id; 46 const char *name; 47 size_t block_len; 48 size_t digest_len; 49 size_t ctx_len; 50 md_init_fn *md_init; 51 md_update_fn *md_update; 52 md_final_fn *md_final; 53 }; 54 55 /* NB. Indexed directly by algorithm number */ 56 const struct ssh_digest digests[SSH_DIGEST_MAX] = { 57 { 58 SSH_DIGEST_MD5, 59 "MD5", 60 MD5_BLOCK_LENGTH, 61 MD5_DIGEST_LENGTH, 62 sizeof(MD5_CTX), 63 (md_init_fn *) MD5Init, 64 (md_update_fn *) MD5Update, 65 (md_final_fn *) MD5Final 66 }, 67 { 68 SSH_DIGEST_SHA1, 69 "SHA1", 70 SHA1_BLOCK_LENGTH, 71 SHA1_DIGEST_LENGTH, 72 sizeof(SHA1_CTX), 73 (md_init_fn *) SHA1Init, 74 (md_update_fn *) SHA1Update, 75 (md_final_fn *) SHA1Final 76 }, 77 { 78 SSH_DIGEST_SHA256, 79 "SHA256", 80 SHA256_BLOCK_LENGTH, 81 SHA256_DIGEST_LENGTH, 82 sizeof(SHA2_CTX), 83 (md_init_fn *) SHA256Init, 84 (md_update_fn *) SHA256Update, 85 (md_final_fn *) SHA256Final 86 }, 87 { 88 SSH_DIGEST_SHA384, 89 "SHA384", 90 SHA384_BLOCK_LENGTH, 91 SHA384_DIGEST_LENGTH, 92 sizeof(SHA2_CTX), 93 (md_init_fn *) SHA384Init, 94 (md_update_fn *) SHA384Update, 95 (md_final_fn *) SHA384Final 96 }, 97 { 98 SSH_DIGEST_SHA512, 99 "SHA512", 100 SHA512_BLOCK_LENGTH, 101 SHA512_DIGEST_LENGTH, 102 sizeof(SHA2_CTX), 103 (md_init_fn *) SHA512Init, 104 (md_update_fn *) SHA512Update, 105 (md_final_fn *) SHA512Final 106 } 107 }; 108 109 static const struct ssh_digest * 110 ssh_digest_by_alg(int alg) 111 { 112 if (alg < 0 || alg >= SSH_DIGEST_MAX) 113 return NULL; 114 if (digests[alg].id != alg) /* sanity */ 115 return NULL; 116 return &(digests[alg]); 117 } 118 119 int 120 ssh_digest_alg_by_name(const char *name) 121 { 122 int alg; 123 124 for (alg = 0; alg < SSH_DIGEST_MAX; alg++) { 125 if (strcasecmp(name, digests[alg].name) == 0) 126 return digests[alg].id; 127 } 128 return -1; 129 } 130 131 const char * 132 ssh_digest_alg_name(int alg) 133 { 134 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 135 136 return digest == NULL ? NULL : digest->name; 137 } 138 139 size_t 140 ssh_digest_bytes(int alg) 141 { 142 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 143 144 return digest == NULL ? 0 : digest->digest_len; 145 } 146 147 size_t 148 ssh_digest_blocksize(struct ssh_digest_ctx *ctx) 149 { 150 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 151 152 return digest == NULL ? 0 : digest->block_len; 153 } 154 155 struct ssh_digest_ctx * 156 ssh_digest_start(int alg) 157 { 158 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 159 struct ssh_digest_ctx *ret; 160 161 if (digest == NULL || (ret = calloc(1, sizeof(*ret))) == NULL) 162 return NULL; 163 if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) { 164 free(ret); 165 return NULL; 166 } 167 ret->alg = alg; 168 digest->md_init(ret->mdctx); 169 return ret; 170 } 171 172 int 173 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to) 174 { 175 const struct ssh_digest *digest = ssh_digest_by_alg(from->alg); 176 177 if (digest == NULL || from->alg != to->alg) 178 return SSH_ERR_INVALID_ARGUMENT; 179 memcpy(to->mdctx, from->mdctx, digest->ctx_len); 180 return 0; 181 } 182 183 int 184 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) 185 { 186 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 187 188 if (digest == NULL) 189 return SSH_ERR_INVALID_ARGUMENT; 190 digest->md_update(ctx->mdctx, m, mlen); 191 return 0; 192 } 193 194 int 195 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b) 196 { 197 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b)); 198 } 199 200 int 201 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) 202 { 203 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 204 205 if (digest == NULL) 206 return SSH_ERR_INVALID_ARGUMENT; 207 if (dlen > UINT_MAX) 208 return SSH_ERR_INVALID_ARGUMENT; 209 if (dlen < digest->digest_len) /* No truncation allowed */ 210 return SSH_ERR_INVALID_ARGUMENT; 211 digest->md_final(d, ctx->mdctx); 212 return 0; 213 } 214 215 void 216 ssh_digest_free(struct ssh_digest_ctx *ctx) 217 { 218 const struct ssh_digest *digest; 219 220 if (ctx != NULL) { 221 digest = ssh_digest_by_alg(ctx->alg); 222 if (digest) { 223 explicit_bzero(ctx->mdctx, digest->ctx_len); 224 free(ctx->mdctx); 225 freezero(ctx, sizeof(*ctx)); 226 } 227 } 228 } 229 230 int 231 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) 232 { 233 struct ssh_digest_ctx *ctx = ssh_digest_start(alg); 234 235 if (ctx == NULL) 236 return SSH_ERR_INVALID_ARGUMENT; 237 if (ssh_digest_update(ctx, m, mlen) != 0 || 238 ssh_digest_final(ctx, d, dlen) != 0) 239 return SSH_ERR_INVALID_ARGUMENT; 240 ssh_digest_free(ctx); 241 return 0; 242 } 243 244 int 245 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen) 246 { 247 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen); 248 } 249