digest-libc.c

   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
  19 #include "includes.h"
  20
  21 #ifndef WITH_OPENSSL
  22
  23 #include <sys/types.h>
  24 #include <limits.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #if 0
  29 #include <md5.h>
  30 #include <rmd160.h>
  31 #endif
  32 #ifdef HAVE_SHA1_H
  33 #include <sha1.h>
  34 #endif
  35 #ifdef HAVE_SHA2_H
  36 #include <sha2.h>
  37 #endif
  38
  39 #if !defined(SHA256_BLOCK_LENGTH) && defined(SHA256_HMAC_BLOCK_SIZE)
  40 #define SHA256_BLOCK_LENGTH SHA256_HMAC_BLOCK_SIZE
  41 #endif
  42 #if !defined(SHA384_BLOCK_LENGTH) && defined(SHA512_HMAC_BLOCK_SIZE)
  43 #define SHA384_BLOCK_LENGTH SHA512_HMAC_BLOCK_SIZE
  44 #endif
  45 #if !defined(SHA512_BLOCK_LENGTH) && defined(SHA512_HMAC_BLOCK_SIZE)
  46 #define SHA512_BLOCK_LENGTH SHA512_HMAC_BLOCK_SIZE
  47 #endif
  48
  49 #include "ssherr.h"
  50 #include "sshbuf.h"
  51 #include "digest.h"
  52
  53 typedef void md_init_fn(void *mdctx);
  54 typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen);
  55 typedef void md_final_fn(u_int8_t[], void *mdctx);
  56
  57 struct ssh_digest_ctx {
  58         int alg;
  59         void *mdctx;
  60 };
  61
  62 struct ssh_digest {
  63         int id;
  64         const char *name;
  65         size_t block_len;
  66         size_t digest_len;
  67         size_t ctx_len;
  68         md_init_fn *md_init;
  69         md_update_fn *md_update;
  70         md_final_fn *md_final;
  71 };
  72
  73 /* NB. Indexed directly by algorithm number */
  74 const struct ssh_digest digests[SSH_DIGEST_MAX] = {
  75         {
  76                 SSH_DIGEST_MD5,
  77                 "MD5",
  78                 MD5_BLOCK_LENGTH,
  79                 MD5_DIGEST_LENGTH,
  80                 sizeof(MD5_CTX),
  81                 (md_init_fn *) MD5Init,
  82                 (md_update_fn *) MD5Update,
  83                 (md_final_fn *) MD5Final
  84         },
  85         {
  86                 SSH_DIGEST_SHA1,
  87                 "SHA1",
  88                 SHA1_BLOCK_LENGTH,
  89                 SHA1_DIGEST_LENGTH,
  90                 sizeof(SHA1_CTX),
  91                 (md_init_fn *) SHA1Init,
  92                 (md_update_fn *) SHA1Update,
  93                 (md_final_fn *) SHA1Final
  94         },
  95         {
  96                 SSH_DIGEST_SHA256,
  97                 "SHA256",
  98                 SHA256_BLOCK_LENGTH,
  99                 SHA256_DIGEST_LENGTH,
 100                 sizeof(SHA2_CTX),
 101                 (md_init_fn *) SHA256Init,
 102                 (md_update_fn *) SHA256Update,
 103                 (md_final_fn *) SHA256Final
 104         },
 105         {
 106                 SSH_DIGEST_SHA384,
 107                 "SHA384",
 108                 SHA384_BLOCK_LENGTH,
 109                 SHA384_DIGEST_LENGTH,
 110                 sizeof(SHA2_CTX),
 111                 (md_init_fn *) SHA384Init,
 112                 (md_update_fn *) SHA384Update,
 113                 (md_final_fn *) SHA384Final
 114         },
 115         {
 116                 SSH_DIGEST_SHA512,
 117                 "SHA512",
 118                 SHA512_BLOCK_LENGTH,
 119                 SHA512_DIGEST_LENGTH,
 120                 sizeof(SHA2_CTX),
 121                 (md_init_fn *) SHA512Init,
 122                 (md_update_fn *) SHA512Update,
 123                 (md_final_fn *) SHA512Final
 124         }
 125 };
 126
 127 static const struct ssh_digest *
 128 ssh_digest_by_alg(int alg)
 129 {
 130         if (alg < 0 || alg >= SSH_DIGEST_MAX)
 131                 return NULL;
 132         if (digests[alg].id != alg) /* sanity */
 133                 return NULL;
 134         return &(digests[alg]);
 135 }
 136
 137 int
 138 ssh_digest_alg_by_name(const char *name)
 139 {
 140         int alg;
 141
 142         for (alg = 0; alg < SSH_DIGEST_MAX; alg++) {
 143                 if (strcasecmp(name, digests[alg].name) == 0)
 144                         return digests[alg].id;
 145         }
 146         return -1;
 147 }
 148
 149 const char *
 150 ssh_digest_alg_name(int alg)
 151 {
 152         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
 153
 154         return digest == NULL ? NULL : digest->name;
 155 }
 156
 157 size_t
 158 ssh_digest_bytes(int alg)
 159 {
 160         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
 161
 162         return digest == NULL ? 0 : digest->digest_len;
 163 }
 164
 165 size_t
 166 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
 167 {
 168         const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
 169
 170         return digest == NULL ? 0 : digest->block_len;
 171 }
 172
 173 struct ssh_digest_ctx *
 174 ssh_digest_start(int alg)
 175 {
 176         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
 177         struct ssh_digest_ctx *ret;
 178
 179         if (digest == NULL || (ret = calloc(1, sizeof(*ret))) == NULL)
 180                 return NULL;
 181         if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) {
 182                 free(ret);
 183                 return NULL;
 184         }
 185         ret->alg = alg;
 186         digest->md_init(ret->mdctx);
 187         return ret;
 188 }
 189
 190 int
 191 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
 192 {
 193         const struct ssh_digest *digest = ssh_digest_by_alg(from->alg);
 194
 195         if (digest == NULL || from->alg != to->alg)
 196                 return SSH_ERR_INVALID_ARGUMENT;
 197         memcpy(to->mdctx, from->mdctx, digest->ctx_len);
 198         return 0;
 199 }
 200
 201 int
 202 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
 203 {
 204         const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
 205
 206         if (digest == NULL)
 207                 return SSH_ERR_INVALID_ARGUMENT;
 208         digest->md_update(ctx->mdctx, m, mlen);
 209         return 0;
 210 }
 211
 212 int
 213 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
 214 {
 215         return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
 216 }
 217
 218 int
 219 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
 220 {
 221         const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
 222
 223         if (digest == NULL)
 224                 return SSH_ERR_INVALID_ARGUMENT;
 225         if (dlen > UINT_MAX)
 226                 return SSH_ERR_INVALID_ARGUMENT;
 227         if (dlen < digest->digest_len) /* No truncation allowed */
 228                 return SSH_ERR_INVALID_ARGUMENT;
 229         digest->md_final(d, ctx->mdctx);
 230         return 0;
 231 }
 232
 233 void
 234 ssh_digest_free(struct ssh_digest_ctx *ctx)
 235 {
 236         const struct ssh_digest *digest;
 237
 238         if (ctx != NULL) {
 239                 digest = ssh_digest_by_alg(ctx->alg);
 240                 if (digest) {
 241                         explicit_bzero(ctx->mdctx, digest->ctx_len);
 242                         free(ctx->mdctx);
 243                         freezero(ctx, sizeof(*ctx));
 244                 }
 245         }
 246 }
 247
 248 int
 249 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
 250 {
 251         struct ssh_digest_ctx *ctx = ssh_digest_start(alg);
 252
 253         if (ctx == NULL)
 254                 return SSH_ERR_INVALID_ARGUMENT;
 255         if (ssh_digest_update(ctx, m, mlen) != 0 ||
 256             ssh_digest_final(ctx, d, dlen) != 0)
 257                 return SSH_ERR_INVALID_ARGUMENT;
 258         ssh_digest_free(ctx);
 259         return 0;
 260 }
 261
 262 int
 263 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
 264 {
 265         return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
 266 }
 267 #endif /* !WITH_OPENSSL */