1 /* $NetBSD: digest-openssl.c,v 1.8 2019/04/20 17:16:40 christos Exp $ */ 2 /* $OpenBSD: digest-openssl.c,v 1.8 2018/09/13 02:08:33 djm Exp $ */ 3 /* 4 * Copyright (c) 2013 Damien Miller <djm@mindrot.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 #include "includes.h" 19 __RCSID("$NetBSD: digest-openssl.c,v 1.8 2019/04/20 17:16:40 christos Exp $"); 20 21 #include <sys/types.h> 22 #include <limits.h> 23 #include <stdlib.h> 24 #include <string.h> 25 26 #include <openssl/evp.h> 27 28 #include "sshbuf.h" 29 #include "digest.h" 30 #include "ssherr.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_SHA1, "SHA1", 20, EVP_sha1 }, 48 { SSH_DIGEST_SHA256, "SHA256", 32, EVP_sha256 }, 49 { SSH_DIGEST_SHA384, "SHA384", 48, EVP_sha384 }, 50 { SSH_DIGEST_SHA512, "SHA512", 64, EVP_sha512 }, 51 { -1, NULL, 0, NULL }, 52 }; 53 54 static const struct ssh_digest * 55 ssh_digest_by_alg(int alg) 56 { 57 if (alg < 0 || alg >= SSH_DIGEST_MAX) 58 return NULL; 59 if (digests[alg].id != alg) /* sanity */ 60 return NULL; 61 return &(digests[alg]); 62 } 63 64 int 65 ssh_digest_alg_by_name(const char *name) 66 { 67 int alg; 68 69 for (alg = 0; digests[alg].id != -1; alg++) { 70 if (strcasecmp(name, digests[alg].name) == 0) 71 return digests[alg].id; 72 } 73 return -1; 74 } 75 76 const char * 77 ssh_digest_alg_name(int alg) 78 { 79 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 80 81 return digest == NULL ? NULL : digest->name; 82 } 83 84 size_t 85 ssh_digest_bytes(int alg) 86 { 87 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 88 89 return digest == NULL ? 0 : digest->digest_len; 90 } 91 92 size_t 93 ssh_digest_blocksize(struct ssh_digest_ctx *ctx) 94 { 95 return EVP_MD_CTX_block_size(ctx->mdctx); 96 } 97 98 struct ssh_digest_ctx * 99 ssh_digest_start(int alg) 100 { 101 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 102 struct ssh_digest_ctx *ret = NULL; 103 104 if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL)) 105 return NULL; 106 ret->alg = alg; 107 if ((ret->mdctx = EVP_MD_CTX_new()) == NULL) { 108 free(ret); 109 return NULL; 110 } 111 if (EVP_DigestInit_ex(ret->mdctx, digest->mdfunc(), NULL) != 1) { 112 ssh_digest_free(ret); 113 return NULL; 114 } 115 return ret; 116 } 117 118 int 119 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to) 120 { 121 if (from->alg != to->alg) 122 return SSH_ERR_INVALID_ARGUMENT; 123 /* we have bcopy-style order while openssl has memcpy-style */ 124 if (!EVP_MD_CTX_copy_ex(to->mdctx, from->mdctx)) 125 return SSH_ERR_LIBCRYPTO_ERROR; 126 return 0; 127 } 128 129 int 130 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) 131 { 132 if (EVP_DigestUpdate(ctx->mdctx, m, mlen) != 1) 133 return SSH_ERR_LIBCRYPTO_ERROR; 134 return 0; 135 } 136 137 int 138 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b) 139 { 140 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b)); 141 } 142 143 int 144 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) 145 { 146 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 147 u_int l = dlen; 148 149 if (digest == NULL || dlen > UINT_MAX) 150 return SSH_ERR_INVALID_ARGUMENT; 151 if (dlen < digest->digest_len) /* No truncation allowed */ 152 return SSH_ERR_INVALID_ARGUMENT; 153 if (EVP_DigestFinal_ex(ctx->mdctx, d, &l) != 1) 154 return SSH_ERR_LIBCRYPTO_ERROR; 155 if (l != digest->digest_len) /* sanity */ 156 return SSH_ERR_INTERNAL_ERROR; 157 return 0; 158 } 159 160 void 161 ssh_digest_free(struct ssh_digest_ctx *ctx) 162 { 163 if (ctx == NULL) 164 return; 165 EVP_MD_CTX_free(ctx->mdctx); 166 freezero(ctx, sizeof(*ctx)); 167 } 168 169 int 170 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) 171 { 172 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 173 u_int mdlen; 174 175 if (digest == NULL) 176 return SSH_ERR_INVALID_ARGUMENT; 177 if (dlen > UINT_MAX) 178 return SSH_ERR_INVALID_ARGUMENT; 179 if (dlen < digest->digest_len) 180 return SSH_ERR_INVALID_ARGUMENT; 181 mdlen = dlen; 182 if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL)) 183 return SSH_ERR_LIBCRYPTO_ERROR; 184 return 0; 185 } 186 187 int 188 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen) 189 { 190 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen); 191 } 192