crypto/openssh/digest-openssl.c

   1 /* $OpenBSD: digest-openssl.c,v 1.7 2017/05/08 22:57:38 djm Exp $ */
   2 /*
   3  * Copyright (c) 2013 Damien Miller <djm@mindrot.org>
   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 #ifdef WITH_OPENSSL
  21
  22 #include <sys/types.h>
  23 #include <limits.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include <openssl/evp.h>
  28
  29 #include "openbsd-compat/openssl-compat.h"
  30
  31 #include "sshbuf.h"
  32 #include "digest.h"
  33 #include "ssherr.h"
  34
  35 #ifndef HAVE_EVP_RIPEMD160
  36 # define EVP_ripemd160 NULL
  37 #endif /* HAVE_EVP_RIPEMD160 */
  38 #ifndef HAVE_EVP_SHA256
  39 # define EVP_sha256 NULL
  40 # define EVP_sha384 NULL
  41 # define EVP_sha512 NULL
  42 #endif /* HAVE_EVP_SHA256 */
  43
  44 struct ssh_digest_ctx {
  45         int alg;
  46         EVP_MD_CTX mdctx;
  47 };
  48
  49 struct ssh_digest {
  50         int id;
  51         const char *name;
  52         size_t digest_len;
  53         const EVP_MD *(*mdfunc)(void);
  54 };
  55
  56 /* NB. Indexed directly by algorithm number */
  57 const struct ssh_digest digests[] = {
  58         { SSH_DIGEST_MD5,       "MD5",          16,     EVP_md5 },
  59         { SSH_DIGEST_SHA1,      "SHA1",         20,     EVP_sha1 },
  60         { SSH_DIGEST_SHA256,    "SHA256",       32,     EVP_sha256 },
  61         { SSH_DIGEST_SHA384,    "SHA384",       48,     EVP_sha384 },
  62         { SSH_DIGEST_SHA512,    "SHA512",       64,     EVP_sha512 },
  63         { -1,                   NULL,           0,      NULL },
  64 };
  65
  66 static const struct ssh_digest *
  67 ssh_digest_by_alg(int alg)
  68 {
  69         if (alg < 0 || alg >= SSH_DIGEST_MAX)
  70                 return NULL;
  71         if (digests[alg].id != alg) /* sanity */
  72                 return NULL;
  73         if (digests[alg].mdfunc == NULL)
  74                 return NULL;
  75         return &(digests[alg]);
  76 }
  77
  78 int
  79 ssh_digest_alg_by_name(const char *name)
  80 {
  81         int alg;
  82
  83         for (alg = 0; digests[alg].id != -1; alg++) {
  84                 if (strcasecmp(name, digests[alg].name) == 0)
  85                         return digests[alg].id;
  86         }
  87         return -1;
  88 }
  89
  90 const char *
  91 ssh_digest_alg_name(int alg)
  92 {
  93         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
  94
  95         return digest == NULL ? NULL : digest->name;
  96 }
  97
  98 size_t
  99 ssh_digest_bytes(int alg)
 100 {
 101         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
 102
 103         return digest == NULL ? 0 : digest->digest_len;
 104 }
 105
 106 size_t
 107 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
 108 {
 109         return EVP_MD_CTX_block_size(&ctx->mdctx);
 110 }
 111
 112 struct ssh_digest_ctx *
 113 ssh_digest_start(int alg)
 114 {
 115         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
 116         struct ssh_digest_ctx *ret;
 117
 118         if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL))
 119                 return NULL;
 120         ret->alg = alg;
 121         EVP_MD_CTX_init(&ret->mdctx);
 122         if (EVP_DigestInit_ex(&ret->mdctx, digest->mdfunc(), NULL) != 1) {
 123                 free(ret);
 124                 return NULL;
 125         }
 126         return ret;
 127 }
 128
 129 int
 130 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
 131 {
 132         if (from->alg != to->alg)
 133                 return SSH_ERR_INVALID_ARGUMENT;
 134         /* we have bcopy-style order while openssl has memcpy-style */
 135         if (!EVP_MD_CTX_copy_ex(&to->mdctx, &from->mdctx))
 136                 return SSH_ERR_LIBCRYPTO_ERROR;
 137         return 0;
 138 }
 139
 140 int
 141 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
 142 {
 143         if (EVP_DigestUpdate(&ctx->mdctx, m, mlen) != 1)
 144                 return SSH_ERR_LIBCRYPTO_ERROR;
 145         return 0;
 146 }
 147
 148 int
 149 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
 150 {
 151         return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
 152 }
 153
 154 int
 155 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
 156 {
 157         const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
 158         u_int l = dlen;
 159
 160         if (digest == NULL || dlen > UINT_MAX)
 161                 return SSH_ERR_INVALID_ARGUMENT;
 162         if (dlen < digest->digest_len) /* No truncation allowed */
 163                 return SSH_ERR_INVALID_ARGUMENT;
 164         if (EVP_DigestFinal_ex(&ctx->mdctx, d, &l) != 1)
 165                 return SSH_ERR_LIBCRYPTO_ERROR;
 166         if (l != digest->digest_len) /* sanity */
 167                 return SSH_ERR_INTERNAL_ERROR;
 168         return 0;
 169 }
 170
 171 void
 172 ssh_digest_free(struct ssh_digest_ctx *ctx)
 173 {
 174         if (ctx != NULL) {
 175                 EVP_MD_CTX_cleanup(&ctx->mdctx);
 176                 explicit_bzero(ctx, sizeof(*ctx));
 177                 free(ctx);
 178         }
 179 }
 180
 181 int
 182 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
 183 {
 184         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
 185         u_int mdlen;
 186
 187         if (digest == NULL)
 188                 return SSH_ERR_INVALID_ARGUMENT;
 189         if (dlen > UINT_MAX)
 190                 return SSH_ERR_INVALID_ARGUMENT;
 191         if (dlen < digest->digest_len)
 192                 return SSH_ERR_INVALID_ARGUMENT;
 193         mdlen = dlen;
 194         if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL))
 195                 return SSH_ERR_LIBCRYPTO_ERROR;
 196         return 0;
 197 }
 198
 199 int
 200 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
 201 {
 202         return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
 203 }
 204 #endif /* WITH_OPENSSL */