1/* $OpenBSD: digest-openssl.c,v 1.9 2020/10/29 02:52:43 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#ifdef WITH_OPENSSL 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 "openbsd-compat/openssl-compat.h" 30 31#include "sshbuf.h" 32#include "digest.h" 33#include "ssherr.h" 34 35#ifndef HAVE_EVP_SHA256 36# define EVP_sha256 NULL 37#endif 38#ifndef HAVE_EVP_SHA384 39# define EVP_sha384 NULL 40#endif 41#ifndef HAVE_EVP_SHA512 42# define EVP_sha512 NULL 43#endif 44 45struct ssh_digest_ctx { 46 int alg; 47 EVP_MD_CTX *mdctx; 48}; 49 50struct ssh_digest { 51 int id; 52 const char *name; 53 size_t digest_len; 54 const EVP_MD *(*mdfunc)(void); 55}; 56 57/* NB. Indexed directly by algorithm number */ 58const struct ssh_digest digests[] = { 59 { SSH_DIGEST_MD5, "MD5", 16, EVP_md5 }, 60 { SSH_DIGEST_SHA1, "SHA1", 20, EVP_sha1 }, 61 { SSH_DIGEST_SHA256, "SHA256", 32, EVP_sha256 }, 62 { SSH_DIGEST_SHA384, "SHA384", 48, EVP_sha384 }, 63 { SSH_DIGEST_SHA512, "SHA512", 64, EVP_sha512 }, 64 { -1, NULL, 0, NULL }, 65}; 66 67static const struct ssh_digest * 68ssh_digest_by_alg(int alg) 69{ 70 if (alg < 0 || alg >= SSH_DIGEST_MAX) 71 return NULL; 72 if (digests[alg].id != alg) /* sanity */ 73 return NULL; 74 if (digests[alg].mdfunc == NULL) 75 return NULL; 76 return &(digests[alg]); 77} 78 79int 80ssh_digest_alg_by_name(const char *name) 81{ 82 int alg; 83 84 for (alg = 0; digests[alg].id != -1; alg++) { 85 if (strcasecmp(name, digests[alg].name) == 0) 86 return digests[alg].id; 87 } 88 return -1; 89} 90 91const char * 92ssh_digest_alg_name(int alg) 93{ 94 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 95 96 return digest == NULL ? NULL : digest->name; 97} 98 99size_t 100ssh_digest_bytes(int alg) 101{ 102 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 103 104 return digest == NULL ? 0 : digest->digest_len; 105} 106 107size_t 108ssh_digest_blocksize(struct ssh_digest_ctx *ctx) 109{ 110 return EVP_MD_CTX_block_size(ctx->mdctx); 111} 112 113struct ssh_digest_ctx * 114ssh_digest_start(int alg) 115{ 116 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 117 struct ssh_digest_ctx *ret; 118 119 if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL)) 120 return NULL; 121 ret->alg = alg; 122 if ((ret->mdctx = EVP_MD_CTX_new()) == NULL) { 123 free(ret); 124 return NULL; 125 } 126 if (EVP_DigestInit_ex(ret->mdctx, digest->mdfunc(), NULL) != 1) { 127 ssh_digest_free(ret); 128 return NULL; 129 } 130 return ret; 131} 132 133int 134ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to) 135{ 136 if (from->alg != to->alg) 137 return SSH_ERR_INVALID_ARGUMENT; 138 /* we have bcopy-style order while openssl has memcpy-style */ 139 if (!EVP_MD_CTX_copy_ex(to->mdctx, from->mdctx)) 140 return SSH_ERR_LIBCRYPTO_ERROR; 141 return 0; 142} 143 144int 145ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) 146{ 147 if (EVP_DigestUpdate(ctx->mdctx, m, mlen) != 1) 148 return SSH_ERR_LIBCRYPTO_ERROR; 149 return 0; 150} 151 152int 153ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b) 154{ 155 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b)); 156} 157 158int 159ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) 160{ 161 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); 162 u_int l = dlen; 163 164 if (digest == NULL || dlen > UINT_MAX) 165 return SSH_ERR_INVALID_ARGUMENT; 166 if (dlen < digest->digest_len) /* No truncation allowed */ 167 return SSH_ERR_INVALID_ARGUMENT; 168 if (EVP_DigestFinal_ex(ctx->mdctx, d, &l) != 1) 169 return SSH_ERR_LIBCRYPTO_ERROR; 170 if (l != digest->digest_len) /* sanity */ 171 return SSH_ERR_INTERNAL_ERROR; 172 return 0; 173} 174 175void 176ssh_digest_free(struct ssh_digest_ctx *ctx) 177{ 178 if (ctx == NULL) 179 return; 180 EVP_MD_CTX_free(ctx->mdctx); 181 freezero(ctx, sizeof(*ctx)); 182} 183 184int 185ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) 186{ 187 const struct ssh_digest *digest = ssh_digest_by_alg(alg); 188 u_int mdlen; 189 190 if (digest == NULL) 191 return SSH_ERR_INVALID_ARGUMENT; 192 if (dlen > UINT_MAX) 193 return SSH_ERR_INVALID_ARGUMENT; 194 if (dlen < digest->digest_len) 195 return SSH_ERR_INVALID_ARGUMENT; 196 mdlen = dlen; 197 if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL)) 198 return SSH_ERR_LIBCRYPTO_ERROR; 199 return 0; 200} 201 202int 203ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen) 204{ 205 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen); 206} 207#endif /* WITH_OPENSSL */ 208