xref: /openbsd-src/lib/libcrypto/hmac/hm_pmeth.c (revision d89ec533011f513df1010f142a111086a0785f09)
1 /* $OpenBSD: hm_pmeth.c,v 1.11 2021/12/12 21:27:38 tb Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project 2007.
4  */
5 /* ====================================================================
6  * Copyright (c) 2007 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58 
59 #include <stdio.h>
60 #include <string.h>
61 
62 #include <openssl/evp.h>
63 #include <openssl/hmac.h>
64 #include <openssl/x509.h>
65 #include <openssl/x509v3.h>
66 
67 #include "evp_locl.h"
68 #include "hmac_local.h"
69 
70 /* HMAC pkey context structure */
71 
72 typedef struct {
73 	const EVP_MD *md;	/* MD for HMAC use */
74 	ASN1_OCTET_STRING ktmp; /* Temp storage for key */
75 	HMAC_CTX ctx;
76 } HMAC_PKEY_CTX;
77 
78 static int
79 pkey_hmac_init(EVP_PKEY_CTX *ctx)
80 {
81 	HMAC_PKEY_CTX *hctx;
82 
83 	hctx = malloc(sizeof(HMAC_PKEY_CTX));
84 	if (!hctx)
85 		return 0;
86 	hctx->md = NULL;
87 	hctx->ktmp.data = NULL;
88 	hctx->ktmp.length = 0;
89 	hctx->ktmp.flags = 0;
90 	hctx->ktmp.type = V_ASN1_OCTET_STRING;
91 	HMAC_CTX_init(&hctx->ctx);
92 
93 	ctx->data = hctx;
94 	ctx->keygen_info_count = 0;
95 
96 	return 1;
97 }
98 
99 static int
100 pkey_hmac_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
101 {
102 	HMAC_PKEY_CTX *sctx, *dctx;
103 
104 	if (!pkey_hmac_init(dst))
105 		return 0;
106 	sctx = src->data;
107 	dctx = dst->data;
108 	dctx->md = sctx->md;
109 	HMAC_CTX_init(&dctx->ctx);
110 	if (!HMAC_CTX_copy(&dctx->ctx, &sctx->ctx))
111 		return 0;
112 	if (sctx->ktmp.data) {
113 		if (!ASN1_OCTET_STRING_set(&dctx->ktmp, sctx->ktmp.data,
114 		    sctx->ktmp.length))
115 			return 0;
116 	}
117 	return 1;
118 }
119 
120 static void
121 pkey_hmac_cleanup(EVP_PKEY_CTX *ctx)
122 {
123 	HMAC_PKEY_CTX *hctx = ctx->data;
124 
125 	HMAC_CTX_cleanup(&hctx->ctx);
126 	freezero(hctx->ktmp.data, hctx->ktmp.length);
127 	free(hctx);
128 }
129 
130 static int
131 pkey_hmac_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
132 {
133 	ASN1_OCTET_STRING *hkey = NULL;
134 	HMAC_PKEY_CTX *hctx = ctx->data;
135 
136 	if (!hctx->ktmp.data)
137 		return 0;
138 	hkey = ASN1_OCTET_STRING_dup(&hctx->ktmp);
139 	if (!hkey)
140 		return 0;
141 	EVP_PKEY_assign(pkey, EVP_PKEY_HMAC, hkey);
142 
143 	return 1;
144 }
145 
146 static int
147 int_update(EVP_MD_CTX *ctx, const void *data, size_t count)
148 {
149 	HMAC_PKEY_CTX *hctx = ctx->pctx->data;
150 
151 	if (!HMAC_Update(&hctx->ctx, data, count))
152 		return 0;
153 	return 1;
154 }
155 
156 static int
157 hmac_signctx_init(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)
158 {
159 	HMAC_PKEY_CTX *hctx = ctx->data;
160 
161 	HMAC_CTX_set_flags(&hctx->ctx, mctx->flags & ~EVP_MD_CTX_FLAG_NO_INIT);
162 	EVP_MD_CTX_set_flags(mctx, EVP_MD_CTX_FLAG_NO_INIT);
163 	mctx->update = int_update;
164 	return 1;
165 }
166 
167 static int
168 hmac_signctx(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
169     EVP_MD_CTX *mctx)
170 {
171 	unsigned int hlen;
172 	HMAC_PKEY_CTX *hctx = ctx->data;
173 	int l = EVP_MD_CTX_size(mctx);
174 
175 	if (l < 0)
176 		return 0;
177 	*siglen = l;
178 	if (!sig)
179 		return 1;
180 
181 	if (!HMAC_Final(&hctx->ctx, sig, &hlen))
182 		return 0;
183 	*siglen = (size_t)hlen;
184 	return 1;
185 }
186 
187 static int
188 pkey_hmac_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
189 {
190 	HMAC_PKEY_CTX *hctx = ctx->data;
191 	ASN1_OCTET_STRING *key;
192 
193 	switch (type) {
194 	case EVP_PKEY_CTRL_SET_MAC_KEY:
195 		if ((!p2 && p1 > 0) || (p1 < -1))
196 			return 0;
197 		if (!ASN1_OCTET_STRING_set(&hctx->ktmp, p2, p1))
198 			return 0;
199 		break;
200 
201 	case EVP_PKEY_CTRL_MD:
202 		hctx->md = p2;
203 		break;
204 
205 	case EVP_PKEY_CTRL_DIGESTINIT:
206 		key = (ASN1_OCTET_STRING *)ctx->pkey->pkey.ptr;
207 		if (!HMAC_Init_ex(&hctx->ctx, key->data, key->length, hctx->md,
208 		    ctx->engine))
209 			return 0;
210 		break;
211 
212 	default:
213 		return -2;
214 	}
215 	return 1;
216 }
217 
218 static int
219 pkey_hmac_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value)
220 {
221 	if (!value)
222 		return 0;
223 	if (!strcmp(type, "key")) {
224 		void *p = (void *)value;
225 		return pkey_hmac_ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, -1, p);
226 	}
227 	if (!strcmp(type, "hexkey")) {
228 		unsigned char *key;
229 		int r;
230 		long keylen;
231 		key = string_to_hex(value, &keylen);
232 		if (!key)
233 			return 0;
234 		r = pkey_hmac_ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, keylen, key);
235 		free(key);
236 		return r;
237 	}
238 	return -2;
239 }
240 
241 const EVP_PKEY_METHOD hmac_pkey_meth = {
242 	.pkey_id = EVP_PKEY_HMAC,
243 
244 	.init = pkey_hmac_init,
245 	.copy = pkey_hmac_copy,
246 	.cleanup = pkey_hmac_cleanup,
247 
248 	.keygen = pkey_hmac_keygen,
249 
250 	.signctx_init = hmac_signctx_init,
251 	.signctx = hmac_signctx,
252 
253 	.ctrl = pkey_hmac_ctrl,
254 	.ctrl_str = pkey_hmac_ctrl_str
255 };
256