1 /* crypto/dsa/dsa_lib.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 
59 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
60 
61 #include <stdio.h>
62 #include "cryptlib.h"
63 #include <openssl/bn.h>
64 #include <openssl/dsa.h>
65 #include <openssl/asn1.h>
66 #ifndef OPENSSL_NO_ENGINE
67 # include <openssl/engine.h>
68 #endif
69 #ifndef OPENSSL_NO_DH
70 # include <openssl/dh.h>
71 #endif
72 
73 #ifdef OPENSSL_FIPS
74 # include <openssl/fips.h>
75 #endif
76 
77 const char DSA_version[] = "DSA" OPENSSL_VERSION_PTEXT;
78 
79 static const DSA_METHOD *default_DSA_method = NULL;
80 
DSA_set_default_method(const DSA_METHOD * meth)81 void DSA_set_default_method(const DSA_METHOD *meth)
82 {
83     default_DSA_method = meth;
84 }
85 
DSA_get_default_method(void)86 const DSA_METHOD *DSA_get_default_method(void)
87 {
88     if (!default_DSA_method) {
89 #ifdef OPENSSL_FIPS
90         if (FIPS_mode())
91             return FIPS_dsa_openssl();
92         else
93             return DSA_OpenSSL();
94 #else
95         default_DSA_method = DSA_OpenSSL();
96 #endif
97     }
98     return default_DSA_method;
99 }
100 
DSA_new(void)101 DSA *DSA_new(void)
102 {
103     return DSA_new_method(NULL);
104 }
105 
DSA_set_method(DSA * dsa,const DSA_METHOD * meth)106 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
107 {
108     /*
109      * NB: The caller is specifically setting a method, so it's not up to us
110      * to deal with which ENGINE it comes from.
111      */
112     const DSA_METHOD *mtmp;
113     mtmp = dsa->meth;
114     if (mtmp->finish)
115         mtmp->finish(dsa);
116 #ifndef OPENSSL_NO_ENGINE
117     if (dsa->engine) {
118         ENGINE_finish(dsa->engine);
119         dsa->engine = NULL;
120     }
121 #endif
122     dsa->meth = meth;
123     if (meth->init)
124         meth->init(dsa);
125     return 1;
126 }
127 
DSA_new_method(ENGINE * engine)128 DSA *DSA_new_method(ENGINE *engine)
129 {
130     DSA *ret;
131 
132     ret = (DSA *)OPENSSL_malloc(sizeof(DSA));
133     if (ret == NULL) {
134         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
135         return (NULL);
136     }
137     ret->meth = DSA_get_default_method();
138 #ifndef OPENSSL_NO_ENGINE
139     if (engine) {
140         if (!ENGINE_init(engine)) {
141             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
142             OPENSSL_free(ret);
143             return NULL;
144         }
145         ret->engine = engine;
146     } else
147         ret->engine = ENGINE_get_default_DSA();
148     if (ret->engine) {
149         ret->meth = ENGINE_get_DSA(ret->engine);
150         if (!ret->meth) {
151             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
152             ENGINE_finish(ret->engine);
153             OPENSSL_free(ret);
154             return NULL;
155         }
156     }
157 #endif
158 
159     ret->pad = 0;
160     ret->version = 0;
161     ret->write_params = 1;
162     ret->p = NULL;
163     ret->q = NULL;
164     ret->g = NULL;
165 
166     ret->pub_key = NULL;
167     ret->priv_key = NULL;
168 
169     ret->kinv = NULL;
170     ret->r = NULL;
171     ret->method_mont_p = NULL;
172 
173     ret->references = 1;
174     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
175     CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
176     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
177 #ifndef OPENSSL_NO_ENGINE
178         if (ret->engine)
179             ENGINE_finish(ret->engine);
180 #endif
181         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
182         OPENSSL_free(ret);
183         ret = NULL;
184     }
185 
186     return (ret);
187 }
188 
DSA_free(DSA * r)189 void DSA_free(DSA *r)
190 {
191     int i;
192 
193     if (r == NULL)
194         return;
195 
196     i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA);
197 #ifdef REF_PRINT
198     REF_PRINT("DSA", r);
199 #endif
200     if (i > 0)
201         return;
202 #ifdef REF_CHECK
203     if (i < 0) {
204         fprintf(stderr, "DSA_free, bad reference count\n");
205         abort();
206     }
207 #endif
208 
209     if (r->meth->finish)
210         r->meth->finish(r);
211 #ifndef OPENSSL_NO_ENGINE
212     if (r->engine)
213         ENGINE_finish(r->engine);
214 #endif
215 
216     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
217 
218     if (r->p != NULL)
219         BN_clear_free(r->p);
220     if (r->q != NULL)
221         BN_clear_free(r->q);
222     if (r->g != NULL)
223         BN_clear_free(r->g);
224     if (r->pub_key != NULL)
225         BN_clear_free(r->pub_key);
226     if (r->priv_key != NULL)
227         BN_clear_free(r->priv_key);
228     if (r->kinv != NULL)
229         BN_clear_free(r->kinv);
230     if (r->r != NULL)
231         BN_clear_free(r->r);
232     OPENSSL_free(r);
233 }
234 
DSA_up_ref(DSA * r)235 int DSA_up_ref(DSA *r)
236 {
237     int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
238 #ifdef REF_PRINT
239     REF_PRINT("DSA", r);
240 #endif
241 #ifdef REF_CHECK
242     if (i < 2) {
243         fprintf(stderr, "DSA_up_ref, bad reference count\n");
244         abort();
245     }
246 #endif
247     return ((i > 1) ? 1 : 0);
248 }
249 
DSA_size(const DSA * r)250 int DSA_size(const DSA *r)
251 {
252     int ret, i;
253     ASN1_INTEGER bs;
254     unsigned char buf[4];       /* 4 bytes looks really small. However,
255                                  * i2d_ASN1_INTEGER() will not look beyond
256                                  * the first byte, as long as the second
257                                  * parameter is NULL. */
258 
259     i = BN_num_bits(r->q);
260     bs.length = (i + 7) / 8;
261     bs.data = buf;
262     bs.type = V_ASN1_INTEGER;
263     /* If the top bit is set the asn1 encoding is 1 larger. */
264     buf[0] = 0xff;
265 
266     i = i2d_ASN1_INTEGER(&bs, NULL);
267     i += i;                     /* r and s */
268     ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
269     return (ret);
270 }
271 
DSA_get_ex_new_index(long argl,void * argp,CRYPTO_EX_new * new_func,CRYPTO_EX_dup * dup_func,CRYPTO_EX_free * free_func)272 int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
273                          CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
274 {
275     return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
276                                    new_func, dup_func, free_func);
277 }
278 
DSA_set_ex_data(DSA * d,int idx,void * arg)279 int DSA_set_ex_data(DSA *d, int idx, void *arg)
280 {
281     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
282 }
283 
DSA_get_ex_data(DSA * d,int idx)284 void *DSA_get_ex_data(DSA *d, int idx)
285 {
286     return (CRYPTO_get_ex_data(&d->ex_data, idx));
287 }
288 
289 #ifndef OPENSSL_NO_DH
DSA_dup_DH(const DSA * r)290 DH *DSA_dup_DH(const DSA *r)
291 {
292     /*
293      * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
294      * optional length, g, optional pub_key, optional priv_key, optional q.
295      */
296 
297     DH *ret = NULL;
298 
299     if (r == NULL)
300         goto err;
301     ret = DH_new();
302     if (ret == NULL)
303         goto err;
304     if (r->p != NULL)
305         if ((ret->p = BN_dup(r->p)) == NULL)
306             goto err;
307     if (r->q != NULL) {
308         ret->length = BN_num_bits(r->q);
309         if ((ret->q = BN_dup(r->q)) == NULL)
310             goto err;
311     }
312     if (r->g != NULL)
313         if ((ret->g = BN_dup(r->g)) == NULL)
314             goto err;
315     if (r->pub_key != NULL)
316         if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
317             goto err;
318     if (r->priv_key != NULL)
319         if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
320             goto err;
321 
322     return ret;
323 
324  err:
325     if (ret != NULL)
326         DH_free(ret);
327     return NULL;
328 }
329 #endif
330