1 /* $OpenBSD: digest-openssl.c,v 1.2 2014/02/02 03:44:31 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 "buffer.h" 26 #include "digest.h" 27 28 struct ssh_digest_ctx { 29 int alg; 30 EVP_MD_CTX mdctx; 31 }; 32 33 struct ssh_digest { 34 int id; 35 const char *name; 36 size_t digest_len; 37 const EVP_MD *(*mdfunc)(void); 38 }; 39 40 /* NB. Indexed directly by algorithm number */ 41 const struct ssh_digest digests[] = { 42 { SSH_DIGEST_MD5, "MD5", 16, EVP_md5 }, 43 { SSH_DIGEST_RIPEMD160, "RIPEMD160", 20, EVP_ripemd160 }, 44 { SSH_DIGEST_SHA1, "SHA1", 20, EVP_sha1 }, 45 { SSH_DIGEST_SHA256, "SHA256", 32, EVP_sha256 }, 46 { SSH_DIGEST_SHA384, "SHA384", 48, EVP_sha384 }, 47 { SSH_DIGEST_SHA512, "SHA512", 64, EVP_sha512 }, 48 { -1, NULL, 0, NULL }, 49 }; 50 51 static const struct ssh_digest * 52 ssh_digest_by_alg(int alg) 53 { 54 if (alg < 0 || alg >= SSH_DIGEST_MAX) 55 return NULL; 56 if (digests[alg].id != alg) /* sanity */ 57 return NULL; 58 return &(digests[alg]); 59 } 60 61 size_t 62 ssh_digest_bytes(int alg) 63 { 64 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 65 66 return digest == NULL ? 0 : digest->digest_len; 67 } 68 69 size_t 70 ssh_digest_blocksize(struct ssh_digest_ctx *ctx) 71 { 72 return EVP_MD_CTX_block_size(&ctx->mdctx); 73 } 74 75 struct ssh_digest_ctx * 76 ssh_digest_start(int alg) 77 { 78 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 79 struct ssh_digest_ctx *ret; 80 81 if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL)) 82 return NULL; 83 ret->alg = alg; 84 EVP_MD_CTX_init(&ret->mdctx); 85 if (EVP_DigestInit_ex(&ret->mdctx, digest->mdfunc(), NULL) != 1) { 86 free(ret); 87 return NULL; 88 } 89 return ret; 90 } 91 92 int 93 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to) 94 { 95 /* we have bcopy-style order while openssl has memcpy-style */ 96 if (!EVP_MD_CTX_copy_ex(&to->mdctx, &from->mdctx)) 97 return -1; 98 return 0; 99 } 100 101 int 102 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) 103 { 104 if (EVP_DigestUpdate(&ctx->mdctx, m, mlen) != 1) 105 return -1; 106 return 0; 107 } 108 109 int 110 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const Buffer *b) 111 { 112 return ssh_digest_update(ctx, buffer_ptr(b), buffer_len(b)); 113 } 114 115 int 116 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) 117 { 118 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 119 u_int l = dlen; 120 121 if (dlen > UINT_MAX) 122 return -1; 123 if (dlen < digest->digest_len) /* No truncation allowed */ 124 return -1; 125 if (EVP_DigestFinal_ex(&ctx->mdctx, d, &l) != 1) 126 return -1; 127 if (l != digest->digest_len) /* sanity */ 128 return -1; 129 return 0; 130 } 131 132 void 133 ssh_digest_free(struct ssh_digest_ctx *ctx) 134 { 135 if (ctx != NULL) { 136 EVP_MD_CTX_cleanup(&ctx->mdctx); 137 explicit_bzero(ctx, sizeof(*ctx)); 138 free(ctx); 139 } 140 } 141 142 int 143 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) 144 { 145 struct ssh_digest_ctx *ctx = ssh_digest_start(alg); 146 147 if (ctx == NULL) 148 return -1; 149 if (ssh_digest_update(ctx, m, mlen) != 0 || 150 ssh_digest_final(ctx, d, dlen) != 0) 151 return -1; 152 ssh_digest_free(ctx); 153 return 0; 154 } 155 156 int 157 ssh_digest_buffer(int alg, const Buffer *b, u_char *d, size_t dlen) 158 { 159 return ssh_digest_memory(alg, buffer_ptr(b), buffer_len(b), d, dlen); 160 } 161