1 /* $NetBSD: digest-openssl.c,v 1.9 2021/03/05 17:47:16 christos Exp $ */ 2 /* $OpenBSD: digest-openssl.c,v 1.9 2020/10/29 02:52:43 djm Exp $ */ 3 4 /* 5 * Copyright (c) 2013 Damien Miller <djm@mindrot.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 #include "includes.h" 20 __RCSID("$NetBSD: digest-openssl.c,v 1.9 2021/03/05 17:47:16 christos Exp $"); 21 22 #include <sys/types.h> 23 #include <limits.h> 24 #include <stdlib.h> 25 #include <string.h> 26 27 #include <openssl/evp.h> 28 29 #include "sshbuf.h" 30 #include "digest.h" 31 #include "ssherr.h" 32 33 struct ssh_digest_ctx { 34 int alg; 35 EVP_MD_CTX *mdctx; 36 }; 37 38 struct ssh_digest { 39 int id; 40 const char *name; 41 size_t digest_len; 42 const EVP_MD *(*mdfunc)(void); 43 }; 44 45 /* NB. Indexed directly by algorithm number */ 46 const struct ssh_digest digests[] = { 47 { SSH_DIGEST_MD5, "MD5", 16, EVP_md5 }, 48 { SSH_DIGEST_SHA1, "SHA1", 20, EVP_sha1 }, 49 { SSH_DIGEST_SHA256, "SHA256", 32, EVP_sha256 }, 50 { SSH_DIGEST_SHA384, "SHA384", 48, EVP_sha384 }, 51 { SSH_DIGEST_SHA512, "SHA512", 64, EVP_sha512 }, 52 { -1, NULL, 0, NULL }, 53 }; 54 55 static const struct ssh_digest * 56 ssh_digest_by_alg(int alg) 57 { 58 if (alg < 0 || alg >= SSH_DIGEST_MAX) 59 return NULL; 60 if (digests[alg].id != alg) /* sanity */ 61 return NULL; 62 return &(digests[alg]); 63 } 64 65 int 66 ssh_digest_alg_by_name(const char *name) 67 { 68 int alg; 69 70 for (alg = 0; digests[alg].id != -1; alg++) { 71 if (strcasecmp(name, digests[alg].name) == 0) 72 return digests[alg].id; 73 } 74 return -1; 75 } 76 77 const char * 78 ssh_digest_alg_name(int alg) 79 { 80 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 81 82 return digest == NULL ? NULL : digest->name; 83 } 84 85 size_t 86 ssh_digest_bytes(int alg) 87 { 88 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 89 90 return digest == NULL ? 0 : digest->digest_len; 91 } 92 93 size_t 94 ssh_digest_blocksize(struct ssh_digest_ctx *ctx) 95 { 96 return EVP_MD_CTX_block_size(ctx->mdctx); 97 } 98 99 struct ssh_digest_ctx * 100 ssh_digest_start(int alg) 101 { 102 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 103 struct ssh_digest_ctx *ret = NULL; 104 105 if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL)) 106 return NULL; 107 ret->alg = alg; 108 if ((ret->mdctx = EVP_MD_CTX_new()) == NULL) { 109 free(ret); 110 return NULL; 111 } 112 if (EVP_DigestInit_ex(ret->mdctx, digest->mdfunc(), NULL) != 1) { 113 ssh_digest_free(ret); 114 return NULL; 115 } 116 return ret; 117 } 118 119 int 120 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to) 121 { 122 if (from->alg != to->alg) 123 return SSH_ERR_INVALID_ARGUMENT; 124 /* we have bcopy-style order while openssl has memcpy-style */ 125 if (!EVP_MD_CTX_copy_ex(to->mdctx, from->mdctx)) 126 return SSH_ERR_LIBCRYPTO_ERROR; 127 return 0; 128 } 129 130 int 131 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) 132 { 133 if (EVP_DigestUpdate(ctx->mdctx, m, mlen) != 1) 134 return SSH_ERR_LIBCRYPTO_ERROR; 135 return 0; 136 } 137 138 int 139 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b) 140 { 141 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b)); 142 } 143 144 int 145 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) 146 { 147 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 148 u_int l = dlen; 149 150 if (digest == NULL || dlen > UINT_MAX) 151 return SSH_ERR_INVALID_ARGUMENT; 152 if (dlen < digest->digest_len) /* No truncation allowed */ 153 return SSH_ERR_INVALID_ARGUMENT; 154 if (EVP_DigestFinal_ex(ctx->mdctx, d, &l) != 1) 155 return SSH_ERR_LIBCRYPTO_ERROR; 156 if (l != digest->digest_len) /* sanity */ 157 return SSH_ERR_INTERNAL_ERROR; 158 return 0; 159 } 160 161 void 162 ssh_digest_free(struct ssh_digest_ctx *ctx) 163 { 164 if (ctx == NULL) 165 return; 166 EVP_MD_CTX_free(ctx->mdctx); 167 freezero(ctx, sizeof(*ctx)); 168 } 169 170 int 171 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) 172 { 173 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 174 u_int mdlen; 175 176 if (digest == NULL) 177 return SSH_ERR_INVALID_ARGUMENT; 178 if (dlen > UINT_MAX) 179 return SSH_ERR_INVALID_ARGUMENT; 180 if (dlen < digest->digest_len) 181 return SSH_ERR_INVALID_ARGUMENT; 182 mdlen = dlen; 183 if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL)) 184 return SSH_ERR_LIBCRYPTO_ERROR; 185 return 0; 186 } 187 188 int 189 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen) 190 { 191 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen); 192 } 193