1 /* $OpenBSD: digest-openssl.c,v 1.5 2014/12/21 22:27:56 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 <sys/types.h> 19 #include <limits.h> 20 #include <stdlib.h> 21 #include <string.h> 22 23 #include <openssl/evp.h> 24 25 #include "sshbuf.h" 26 #include "digest.h" 27 #include "ssherr.h" 28 29 struct ssh_digest_ctx { 30 int alg; 31 EVP_MD_CTX mdctx; 32 }; 33 34 struct ssh_digest { 35 int id; 36 const char *name; 37 size_t digest_len; 38 const EVP_MD *(*mdfunc)(void); 39 }; 40 41 /* NB. Indexed directly by algorithm number */ 42 const struct ssh_digest digests[] = { 43 { SSH_DIGEST_MD5, "MD5", 16, EVP_md5 }, 44 { SSH_DIGEST_RIPEMD160, "RIPEMD160", 20, EVP_ripemd160 }, 45 { SSH_DIGEST_SHA1, "SHA1", 20, EVP_sha1 }, 46 { SSH_DIGEST_SHA256, "SHA256", 32, EVP_sha256 }, 47 { SSH_DIGEST_SHA384, "SHA384", 48, EVP_sha384 }, 48 { SSH_DIGEST_SHA512, "SHA512", 64, EVP_sha512 }, 49 { -1, NULL, 0, NULL }, 50 }; 51 52 static const struct ssh_digest * 53 ssh_digest_by_alg(int alg) 54 { 55 if (alg < 0 || alg >= SSH_DIGEST_MAX) 56 return NULL; 57 if (digests[alg].id != alg) /* sanity */ 58 return NULL; 59 return &(digests[alg]); 60 } 61 62 int 63 ssh_digest_alg_by_name(const char *name) 64 { 65 int alg; 66 67 for (alg = 0; digests[alg].id != -1; alg++) { 68 if (strcasecmp(name, digests[alg].name) == 0) 69 return digests[alg].id; 70 } 71 return -1; 72 } 73 74 const char * 75 ssh_digest_alg_name(int alg) 76 { 77 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 78 79 return digest == NULL ? NULL : digest->name; 80 } 81 82 size_t 83 ssh_digest_bytes(int alg) 84 { 85 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 86 87 return digest == NULL ? 0 : digest->digest_len; 88 } 89 90 size_t 91 ssh_digest_blocksize(struct ssh_digest_ctx *ctx) 92 { 93 return EVP_MD_CTX_block_size(&ctx->mdctx); 94 } 95 96 struct ssh_digest_ctx * 97 ssh_digest_start(int alg) 98 { 99 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 100 struct ssh_digest_ctx *ret; 101 102 if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL)) 103 return NULL; 104 ret->alg = alg; 105 EVP_MD_CTX_init(&ret->mdctx); 106 if (EVP_DigestInit_ex(&ret->mdctx, digest->mdfunc(), NULL) != 1) { 107 free(ret); 108 return NULL; 109 } 110 return ret; 111 } 112 113 int 114 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to) 115 { 116 if (from->alg != to->alg) 117 return SSH_ERR_INVALID_ARGUMENT; 118 /* we have bcopy-style order while openssl has memcpy-style */ 119 if (!EVP_MD_CTX_copy_ex(&to->mdctx, &from->mdctx)) 120 return SSH_ERR_LIBCRYPTO_ERROR; 121 return 0; 122 } 123 124 int 125 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) 126 { 127 if (EVP_DigestUpdate(&ctx->mdctx, m, mlen) != 1) 128 return SSH_ERR_LIBCRYPTO_ERROR; 129 return 0; 130 } 131 132 int 133 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b) 134 { 135 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b)); 136 } 137 138 int 139 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) 140 { 141 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 142 u_int l = dlen; 143 144 if (dlen > UINT_MAX) 145 return SSH_ERR_INVALID_ARGUMENT; 146 if (dlen < digest->digest_len) /* No truncation allowed */ 147 return SSH_ERR_INVALID_ARGUMENT; 148 if (EVP_DigestFinal_ex(&ctx->mdctx, d, &l) != 1) 149 return SSH_ERR_LIBCRYPTO_ERROR; 150 if (l != digest->digest_len) /* sanity */ 151 return SSH_ERR_INTERNAL_ERROR; 152 return 0; 153 } 154 155 void 156 ssh_digest_free(struct ssh_digest_ctx *ctx) 157 { 158 if (ctx != NULL) { 159 EVP_MD_CTX_cleanup(&ctx->mdctx); 160 explicit_bzero(ctx, sizeof(*ctx)); 161 free(ctx); 162 } 163 } 164 165 int 166 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) 167 { 168 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 169 u_int mdlen; 170 171 if (digest == NULL) 172 return SSH_ERR_INVALID_ARGUMENT; 173 if (dlen > UINT_MAX) 174 return SSH_ERR_INVALID_ARGUMENT; 175 if (dlen < digest->digest_len) 176 return SSH_ERR_INVALID_ARGUMENT; 177 mdlen = dlen; 178 if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL)) 179 return SSH_ERR_LIBCRYPTO_ERROR; 180 return 0; 181 } 182 183 int 184 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen) 185 { 186 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen); 187 } 188