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