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 } 183