Damien Miller | b3051d0 | 2014-01-10 10:58:53 +1100 | [diff] [blame^] | 1 | /* $OpenBSD: digest.c,v 1.1 2014/01/09 23:20:00 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/bn.h> /* for buffer.h */ |
| 26 | #include <openssl/ec.h> /* for buffer.h */ |
| 27 | #include <openssl/evp.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 | 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_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen) |
| 94 | { |
| 95 | if (EVP_DigestUpdate(&ctx->mdctx, m, mlen) != 1) |
| 96 | return -1; |
| 97 | return 0; |
| 98 | } |
| 99 | |
| 100 | int |
| 101 | ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const Buffer *b) |
| 102 | { |
| 103 | return ssh_digest_update(ctx, buffer_ptr(b), buffer_len(b)); |
| 104 | } |
| 105 | |
| 106 | int |
| 107 | ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen) |
| 108 | { |
| 109 | const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg); |
| 110 | u_int l = dlen; |
| 111 | |
| 112 | if (dlen > UINT_MAX) |
| 113 | return -1; |
| 114 | if (dlen < digest->digest_len) /* No truncation allowed */ |
| 115 | return -1; |
| 116 | if (EVP_DigestFinal_ex(&ctx->mdctx, d, &l) != 1) |
| 117 | return -1; |
| 118 | if (l != digest->digest_len) /* sanity */ |
| 119 | return -1; |
| 120 | return 0; |
| 121 | } |
| 122 | |
| 123 | void |
| 124 | ssh_digest_free(struct ssh_digest_ctx *ctx) |
| 125 | { |
| 126 | EVP_MD_CTX_cleanup(&ctx->mdctx); |
| 127 | memset(ctx, 0, sizeof(*ctx)); |
| 128 | } |
| 129 | |
| 130 | int |
| 131 | ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen) |
| 132 | { |
| 133 | struct ssh_digest_ctx *ctx = ssh_digest_start(alg); |
| 134 | |
| 135 | if (ctx == NULL) |
| 136 | return -1; |
| 137 | if (ssh_digest_update(ctx, m, mlen) != 0 || |
| 138 | ssh_digest_final(ctx, d, dlen) != 0) |
| 139 | return -1; |
| 140 | ssh_digest_free(ctx); |
| 141 | return 0; |
| 142 | } |
| 143 | |
| 144 | int |
| 145 | ssh_digest_buffer(int alg, const Buffer *b, u_char *d, size_t dlen) |
| 146 | { |
| 147 | return ssh_digest_memory(alg, buffer_ptr(b), buffer_len(b), d, dlen); |
| 148 | } |