crypto/openssh/digest-openssl.c

   1 /* $OpenBSD: digest-openssl.c,v 1.4 2014/07/03 03:26:43 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 #include <sys/types.h>
  21 #include <limits.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <openssl/evp.h>
  26
  27 #include "openbsd-compat/openssl-compat.h"
  28
  29 #include "sshbuf.h"
  30 #include "digest.h"
  31 #include "ssherr.h"
  32
  33 #ifndef HAVE_EVP_RIPEMD160
  34 # define EVP_ripemd160 NULL
  35 #endif /* HAVE_EVP_RIPEMD160 */
  36 #ifndef HAVE_EVP_SHA256
  37 # define EVP_sha256 NULL
  38 # define EVP_sha384 NULL
  39 # define EVP_sha512 NULL
  40 #endif /* HAVE_EVP_SHA256 */
  41
  42 struct ssh_digest_ctx {
  43         int alg;
  44         EVP_MD_CTX mdctx;
  45 };
  46
  47 struct ssh_digest {
  48         int id;
  49         const char *name;
  50         size_t digest_len;
  51         const EVP_MD *(*mdfunc)(void);
  52 };
  53
  54 /* NB. Indexed directly by algorithm number */
  55 const struct ssh_digest digests[] = {
  56         { SSH_DIGEST_MD5,       "MD5",          16,     EVP_md5 },
  57         { SSH_DIGEST_RIPEMD160, "RIPEMD160",    20,     EVP_ripemd160 },
  58         { SSH_DIGEST_SHA1,      "SHA1",         20,     EVP_sha1 },
  59         { SSH_DIGEST_SHA256,    "SHA256",       32,     EVP_sha256 },
  60         { SSH_DIGEST_SHA384,    "SHA384",       48,     EVP_sha384 },
  61         { SSH_DIGEST_SHA512,    "SHA512",       64,     EVP_sha512 },
  62         { -1,                   NULL,           0,      NULL },
  63 };
  64
  65 static const struct ssh_digest *
  66 ssh_digest_by_alg(int alg)
  67 {
  68         if (alg < 0 || alg >= SSH_DIGEST_MAX)
  69                 return NULL;
  70         if (digests[alg].id != alg) /* sanity */
  71                 return NULL;
  72         if (digests[alg].mdfunc == NULL)
  73                 return NULL;
  74         return &(digests[alg]);
  75 }
  76
  77 size_t
  78 ssh_digest_bytes(int alg)
  79 {
  80         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
  81
  82         return digest == NULL ? 0 : digest->digest_len;
  83 }
  84
  85 size_t
  86 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
  87 {
  88         return EVP_MD_CTX_block_size(&ctx->mdctx);
  89 }
  90
  91 struct ssh_digest_ctx *
  92 ssh_digest_start(int alg)
  93 {
  94         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
  95         struct ssh_digest_ctx *ret;
  96
  97         if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL))
  98                 return NULL;
  99         ret->alg = alg;
 100         EVP_MD_CTX_init(&ret->mdctx);
 101         if (EVP_DigestInit_ex(&ret->mdctx, digest->mdfunc(), NULL) != 1) {
 102                 free(ret);
 103                 return NULL;
 104         }
 105         return ret;
 106 }
 107
 108 int
 109 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
 110 {
 111         if (from->alg != to->alg)
 112                 return SSH_ERR_INVALID_ARGUMENT;
 113         /* we have bcopy-style order while openssl has memcpy-style */
 114         if (!EVP_MD_CTX_copy_ex(&to->mdctx, &from->mdctx))
 115                 return SSH_ERR_LIBCRYPTO_ERROR;
 116         return 0;
 117 }
 118
 119 int
 120 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
 121 {
 122         if (EVP_DigestUpdate(&ctx->mdctx, m, mlen) != 1)
 123                 return SSH_ERR_LIBCRYPTO_ERROR;
 124         return 0;
 125 }
 126
 127 int
 128 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
 129 {
 130         return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
 131 }
 132
 133 int
 134 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
 135 {
 136         const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
 137         u_int l = dlen;
 138
 139         if (dlen > UINT_MAX)
 140                 return SSH_ERR_INVALID_ARGUMENT;
 141         if (dlen < digest->digest_len) /* No truncation allowed */
 142                 return SSH_ERR_INVALID_ARGUMENT;
 143         if (EVP_DigestFinal_ex(&ctx->mdctx, d, &l) != 1)
 144                 return SSH_ERR_LIBCRYPTO_ERROR;
 145         if (l != digest->digest_len) /* sanity */
 146                 return SSH_ERR_INTERNAL_ERROR;
 147         return 0;
 148 }
 149
 150 void
 151 ssh_digest_free(struct ssh_digest_ctx *ctx)
 152 {
 153         if (ctx != NULL) {
 154                 EVP_MD_CTX_cleanup(&ctx->mdctx);
 155                 explicit_bzero(ctx, sizeof(*ctx));
 156                 free(ctx);
 157         }
 158 }
 159
 160 int
 161 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
 162 {
 163         const struct ssh_digest *digest = ssh_digest_by_alg(alg);
 164         u_int mdlen;
 165
 166         if (digest == NULL)
 167                 return SSH_ERR_INVALID_ARGUMENT;
 168         if (dlen > UINT_MAX)
 169                 return SSH_ERR_INVALID_ARGUMENT;
 170         if (dlen < digest->digest_len)
 171                 return SSH_ERR_INVALID_ARGUMENT;
 172         mdlen = dlen;
 173         if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL))
 174                 return SSH_ERR_LIBCRYPTO_ERROR;
 175         return 0;
 176 }
 177
 178 int
 179 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
 180 {
 181         return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
 182 }