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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 <sys/types.h>
19#include <limits.h>
20#include <stdlib.h>
21#include <string.h>
22
23#include <openssl/evp.h>
24
25#include "sshbuf.h"
26#include "digest.h"
27#include "ssherr.h"
28
29struct ssh_digest_ctx {
30 int alg;
31 EVP_MD_CTX *mdctx;
32};
33
34struct ssh_digest {
35 int id;
36 const char *name;
37 size_t digest_len;
38 const EVP_MD *(*mdfunc)(void);
39};
40
41/* NB. Indexed directly by algorithm number */
42const struct ssh_digest digests[] = {
43 { SSH_DIGEST_MD5, "MD5", 16, EVP_md5 },
44 { SSH_DIGEST_SHA1, "SHA1", 20, EVP_sha1 },
45 { SSH_DIGEST_SHA256, "SHA256", 32, EVP_sha256 },
46 { SSH_DIGEST_SHA384, "SHA384", 48, EVP_sha384 },
47 { SSH_DIGEST_SHA512, "SHA512", 64, EVP_sha512 },
48 { -1, NULL, 0, NULL },
49};
50
51static const struct ssh_digest *
52ssh_digest_by_alg(int alg)
53{
54 if (alg < 0 || alg >= SSH_DIGEST_MAX)
55 return NULL;
56 if (digests[alg].id != alg) /* sanity */
57 return NULL;
58 return &(digests[alg]);
59}
60
61int
62ssh_digest_alg_by_name(const char *name)
63{
64 int alg;
65
66 for (alg = 0; digests[alg].id != -1; alg++) {
67 if (strcasecmp(name, digests[alg].name) == 0)
68 return digests[alg].id;
69 }
70 return -1;
71}
72
73const char *
74ssh_digest_alg_name(int alg)
75{
76 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
77
78 return digest == NULL ? NULL : digest->name;
79}
80
81size_t
82ssh_digest_bytes(int alg)
83{
84 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
85
86 return digest == NULL ? 0 : digest->digest_len;
87}
88
89size_t
90ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
91{
92 return EVP_MD_CTX_block_size(ctx->mdctx);
93}
94
95struct ssh_digest_ctx *
96ssh_digest_start(int alg)
97{
98 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
99 struct ssh_digest_ctx *ret;
100
101 if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL))
102 return NULL;
103 ret->alg = alg;
104 if ((ret->mdctx = EVP_MD_CTX_new()) == NULL) {
105 free(ret);
106 return NULL;
107 }
108 if (EVP_DigestInit_ex(ret->mdctx, digest->mdfunc(), NULL) != 1) {
109 ssh_digest_free(ret);
110 return NULL;
111 }
112 return ret;
113}
114
115int
116ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
117{
118 if (from->alg != to->alg)
119 return SSH_ERR_INVALID_ARGUMENT;
120 /* we have bcopy-style order while openssl has memcpy-style */
121 if (!EVP_MD_CTX_copy_ex(to->mdctx, from->mdctx))
122 return SSH_ERR_LIBCRYPTO_ERROR;
123 return 0;
124}
125
126int
127ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
128{
129 if (EVP_DigestUpdate(ctx->mdctx, m, mlen) != 1)
130 return SSH_ERR_LIBCRYPTO_ERROR;
131 return 0;
132}
133
134int
135ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
136{
137 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
138}
139
140int
141ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
142{
143 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
144 u_int l = dlen;
145
146 if (digest == NULL || dlen > UINT_MAX)
147 return SSH_ERR_INVALID_ARGUMENT;
148 if (dlen < digest->digest_len) /* No truncation allowed */
149 return SSH_ERR_INVALID_ARGUMENT;
150 if (EVP_DigestFinal_ex(ctx->mdctx, d, &l) != 1)
151 return SSH_ERR_LIBCRYPTO_ERROR;
152 if (l != digest->digest_len) /* sanity */
153 return SSH_ERR_INTERNAL_ERROR;
154 return 0;
155}
156
157void
158ssh_digest_free(struct ssh_digest_ctx *ctx)
159{
160 if (ctx == NULL)
161 return;
162 EVP_MD_CTX_free(ctx->mdctx);
163 freezero(ctx, sizeof(*ctx));
164}
165
166int
167ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
168{
169 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
170 u_int mdlen;
171
172 if (digest == NULL)
173 return SSH_ERR_INVALID_ARGUMENT;
174 if (dlen > UINT_MAX)
175 return SSH_ERR_INVALID_ARGUMENT;
176 if (dlen < digest->digest_len)
177 return SSH_ERR_INVALID_ARGUMENT;
178 mdlen = dlen;
179 if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL))
180 return SSH_ERR_LIBCRYPTO_ERROR;
181 return 0;
182}
183
184int
185ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
186{
187 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
188}