1 /* $OpenBSD: dsa_pmeth.c,v 1.11 2017/01/29 17:49:22 beck Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project 2006.
4  */
5 /* ====================================================================
6  * Copyright (c) 2006 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 <limits.h>
60 #include <stdio.h>
61 #include <string.h>
62 
63 #include <openssl/asn1t.h>
64 #include <openssl/bn.h>
65 #include <openssl/err.h>
66 #include <openssl/evp.h>
67 #include <openssl/x509.h>
68 
69 #include "dsa_locl.h"
70 #include "evp_locl.h"
71 
72 /* DSA pkey context structure */
73 
74 typedef struct {
75 	/* Parameter gen parameters */
76 	int nbits;		/* size of p in bits (default: 1024) */
77 	int qbits;		/* size of q in bits (default: 160)  */
78 	const EVP_MD *pmd;	/* MD for parameter generation */
79 	/* Keygen callback info */
80 	int gentmp[2];
81 	/* message digest */
82 	const EVP_MD *md;	/* MD for the signature */
83 } DSA_PKEY_CTX;
84 
85 static int
86 pkey_dsa_init(EVP_PKEY_CTX *ctx)
87 {
88 	DSA_PKEY_CTX *dctx;
89 
90 	dctx = malloc(sizeof(DSA_PKEY_CTX));
91 	if (!dctx)
92 		return 0;
93 	dctx->nbits = 1024;
94 	dctx->qbits = 160;
95 	dctx->pmd = NULL;
96 	dctx->md = NULL;
97 
98 	ctx->data = dctx;
99 	ctx->keygen_info = dctx->gentmp;
100 	ctx->keygen_info_count = 2;
101 
102 	return 1;
103 }
104 
105 static int
106 pkey_dsa_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
107 {
108 	DSA_PKEY_CTX *dctx, *sctx;
109 
110 	if (!pkey_dsa_init(dst))
111 		return 0;
112        	sctx = src->data;
113 	dctx = dst->data;
114 	dctx->nbits = sctx->nbits;
115 	dctx->qbits = sctx->qbits;
116 	dctx->pmd = sctx->pmd;
117 	dctx->md  = sctx->md;
118 	return 1;
119 }
120 
121 static void
122 pkey_dsa_cleanup(EVP_PKEY_CTX *ctx)
123 {
124 	DSA_PKEY_CTX *dctx = ctx->data;
125 
126 	free(dctx);
127 }
128 
129 static int
130 pkey_dsa_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
131     const unsigned char *tbs, size_t tbslen)
132 {
133 	int ret, type;
134 	unsigned int sltmp;
135 	DSA_PKEY_CTX *dctx = ctx->data;
136 	DSA *dsa = ctx->pkey->pkey.dsa;
137 
138 	if (dctx->md)
139 		type = EVP_MD_type(dctx->md);
140 	else
141 		type = NID_sha1;
142 
143 	ret = DSA_sign(type, tbs, tbslen, sig, &sltmp, dsa);
144 
145 	if (ret <= 0)
146 		return ret;
147 	*siglen = sltmp;
148 	return 1;
149 }
150 
151 static int
152 pkey_dsa_verify(EVP_PKEY_CTX *ctx, const unsigned char *sig, size_t siglen,
153     const unsigned char *tbs, size_t tbslen)
154 {
155 	int ret, type;
156 	DSA_PKEY_CTX *dctx = ctx->data;
157 	DSA *dsa = ctx->pkey->pkey.dsa;
158 
159 	if (dctx->md)
160 		type = EVP_MD_type(dctx->md);
161 	else
162 		type = NID_sha1;
163 
164 	ret = DSA_verify(type, tbs, tbslen, sig, siglen, dsa);
165 
166 	return ret;
167 }
168 
169 static int
170 pkey_dsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
171 {
172 	DSA_PKEY_CTX *dctx = ctx->data;
173 
174 	switch (type) {
175 	case EVP_PKEY_CTRL_DSA_PARAMGEN_BITS:
176 		if (p1 < 256)
177 			return -2;
178 		dctx->nbits = p1;
179 		return 1;
180 
181 	case EVP_PKEY_CTRL_DSA_PARAMGEN_Q_BITS:
182 		if (p1 != 160 && p1 != 224 && p1 && p1 != 256)
183 			return -2;
184 		dctx->qbits = p1;
185 		return 1;
186 
187 	case EVP_PKEY_CTRL_DSA_PARAMGEN_MD:
188 		switch (EVP_MD_type((const EVP_MD *)p2)) {
189 		case NID_sha1:
190 		case NID_sha224:
191 		case NID_sha256:
192 			break;
193 		default:
194 			DSAerror(DSA_R_INVALID_DIGEST_TYPE);
195 			return 0;
196 		}
197 		dctx->md = p2;
198 		return 1;
199 
200 	case EVP_PKEY_CTRL_MD:
201 		switch (EVP_MD_type((const EVP_MD *)p2)) {
202 		case NID_sha1:
203 		case NID_dsa:
204 		case NID_dsaWithSHA:
205 		case NID_sha224:
206 		case NID_sha256:
207 		case NID_sha384:
208 		case NID_sha512:
209 			break;
210 		default:
211 			DSAerror(DSA_R_INVALID_DIGEST_TYPE);
212 			return 0;
213 		}
214 		dctx->md = p2;
215 		return 1;
216 
217 	case EVP_PKEY_CTRL_DIGESTINIT:
218 	case EVP_PKEY_CTRL_PKCS7_SIGN:
219 	case EVP_PKEY_CTRL_CMS_SIGN:
220 		return 1;
221 
222 	case EVP_PKEY_CTRL_PEER_KEY:
223 		DSAerror(EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
224 		return -2;
225 	default:
226 		return -2;
227 	}
228 }
229 
230 static int
231 pkey_dsa_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value)
232 {
233  	long lval;
234 	char *ep;
235 
236 	if (!strcmp(type, "dsa_paramgen_bits")) {
237 		int nbits;
238 
239 		errno = 0;
240 		lval = strtol(value, &ep, 10);
241 		if (value[0] == '\0' || *ep != '\0')
242 			goto not_a_number;
243 		if ((errno == ERANGE &&
244 		    (lval == LONG_MAX || lval == LONG_MIN)) ||
245 		    (lval > INT_MAX || lval < INT_MIN))
246 			goto out_of_range;
247 		nbits = lval;
248 		return EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, nbits);
249 	} else if (!strcmp(type, "dsa_paramgen_q_bits")) {
250 		int qbits;
251 
252 		errno = 0;
253 		lval = strtol(value, &ep, 10);
254 		if (value[0] == '\0' || *ep != '\0')
255 			goto not_a_number;
256 		if ((errno == ERANGE &&
257 		    (lval == LONG_MAX || lval == LONG_MIN)) ||
258 		    (lval > INT_MAX || lval < INT_MIN))
259 			goto out_of_range;
260 		qbits = lval;
261 		return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DSA,
262 		    EVP_PKEY_OP_PARAMGEN, EVP_PKEY_CTRL_DSA_PARAMGEN_Q_BITS,
263 		    qbits, NULL);
264 	} else if (!strcmp(type, "dsa_paramgen_md")) {
265 		return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DSA,
266 		    EVP_PKEY_OP_PARAMGEN, EVP_PKEY_CTRL_DSA_PARAMGEN_MD, 0,
267 		    (void *)EVP_get_digestbyname(value));
268 	}
269 not_a_number:
270 out_of_range:
271 	return -2;
272 }
273 
274 static int
275 pkey_dsa_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
276 {
277 	DSA *dsa = NULL;
278 	DSA_PKEY_CTX *dctx = ctx->data;
279 	BN_GENCB *pcb, cb;
280 	int ret;
281 
282 	if (ctx->pkey_gencb) {
283 		pcb = &cb;
284 		evp_pkey_set_cb_translate(pcb, ctx);
285 	} else
286 		pcb = NULL;
287 	dsa = DSA_new();
288 	if (!dsa)
289 		return 0;
290 	ret = dsa_builtin_paramgen(dsa, dctx->nbits, dctx->qbits, dctx->pmd,
291 	    NULL, 0, NULL, NULL, NULL, pcb);
292 	if (ret)
293 		EVP_PKEY_assign_DSA(pkey, dsa);
294 	else
295 		DSA_free(dsa);
296 	return ret;
297 }
298 
299 static int
300 pkey_dsa_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
301 {
302 	DSA *dsa = NULL;
303 
304 	if (ctx->pkey == NULL) {
305 		DSAerror(DSA_R_NO_PARAMETERS_SET);
306 		return 0;
307 	}
308 	dsa = DSA_new();
309 	if (!dsa)
310 		return 0;
311 	EVP_PKEY_assign_DSA(pkey, dsa);
312 	/* Note: if error return, pkey is freed by parent routine */
313 	if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
314 		return 0;
315 	return DSA_generate_key(pkey->pkey.dsa);
316 }
317 
318 const EVP_PKEY_METHOD dsa_pkey_meth = {
319 	.pkey_id = EVP_PKEY_DSA,
320 	.flags = EVP_PKEY_FLAG_AUTOARGLEN,
321 
322 	.init = pkey_dsa_init,
323 	.copy = pkey_dsa_copy,
324 	.cleanup = pkey_dsa_cleanup,
325 
326 	.paramgen = pkey_dsa_paramgen,
327 
328 	.keygen = pkey_dsa_keygen,
329 
330 	.sign = pkey_dsa_sign,
331 
332 	.verify = pkey_dsa_verify,
333 
334 	.ctrl = pkey_dsa_ctrl,
335 	.ctrl_str = pkey_dsa_ctrl_str
336 };
337