xref: /openbsd-src/lib/libcrypto/rsa/rsa_lib.c (revision b725ae7711052a2233e31a66fefb8a752c388d7a)
1 /* crypto/rsa/rsa_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 #include <stdio.h>
60 #include <openssl/crypto.h>
61 #include "cryptlib.h"
62 #include <openssl/lhash.h>
63 #include <openssl/bn.h>
64 #include <openssl/rsa.h>
65 #include <openssl/rand.h>
66 #ifndef OPENSSL_NO_ENGINE
67 #include <openssl/engine.h>
68 #endif
69 
70 const char *RSA_version="RSA" OPENSSL_VERSION_PTEXT;
71 
72 static const RSA_METHOD *default_RSA_meth=NULL;
73 
74 RSA *RSA_new(void)
75 	{
76 	RSA *r=RSA_new_method(NULL);
77 
78 	return r;
79 	}
80 
81 void RSA_set_default_method(const RSA_METHOD *meth)
82 	{
83 	default_RSA_meth = meth;
84 	}
85 
86 const RSA_METHOD *RSA_get_default_method(void)
87 	{
88 	if (default_RSA_meth == NULL)
89 		{
90 #ifdef RSA_NULL
91 		default_RSA_meth=RSA_null_method();
92 #else
93 #if 0 /* was: #ifdef RSAref */
94 		default_RSA_meth=RSA_PKCS1_RSAref();
95 #else
96 		default_RSA_meth=RSA_PKCS1_SSLeay();
97 #endif
98 #endif
99 		}
100 
101 	return default_RSA_meth;
102 	}
103 
104 const RSA_METHOD *RSA_get_method(const RSA *rsa)
105 	{
106 	return rsa->meth;
107 	}
108 
109 int RSA_set_method(RSA *rsa, const RSA_METHOD *meth)
110 	{
111 	/* NB: The caller is specifically setting a method, so it's not up to us
112 	 * to deal with which ENGINE it comes from. */
113 	const RSA_METHOD *mtmp;
114 	mtmp = rsa->meth;
115 	if (mtmp->finish) mtmp->finish(rsa);
116 #ifndef OPENSSL_NO_ENGINE
117 	if (rsa->engine)
118 		{
119 		ENGINE_finish(rsa->engine);
120 		rsa->engine = NULL;
121 		}
122 #endif
123 	rsa->meth = meth;
124 	if (meth->init) meth->init(rsa);
125 	return 1;
126 	}
127 
128 RSA *RSA_new_method(ENGINE *engine)
129 	{
130 	RSA *ret;
131 
132 	ret=(RSA *)OPENSSL_malloc(sizeof(RSA));
133 	if (ret == NULL)
134 		{
135 		RSAerr(RSA_F_RSA_NEW_METHOD,ERR_R_MALLOC_FAILURE);
136 		return NULL;
137 		}
138 
139 	ret->meth = RSA_get_default_method();
140 #ifndef OPENSSL_NO_ENGINE
141 	if (engine)
142 		{
143 		if (!ENGINE_init(engine))
144 			{
145 			RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_ENGINE_LIB);
146 			OPENSSL_free(ret);
147 			return NULL;
148 			}
149 		ret->engine = engine;
150 		}
151 	else
152 		ret->engine = ENGINE_get_default_RSA();
153 	if(ret->engine)
154 		{
155 		ret->meth = ENGINE_get_RSA(ret->engine);
156 		if(!ret->meth)
157 			{
158 			RSAerr(RSA_F_RSA_NEW_METHOD,
159 				ERR_R_ENGINE_LIB);
160 			ENGINE_finish(ret->engine);
161 			OPENSSL_free(ret);
162 			return NULL;
163 			}
164 		}
165 #endif
166 
167 	ret->pad=0;
168 	ret->version=0;
169 	ret->n=NULL;
170 	ret->e=NULL;
171 	ret->d=NULL;
172 	ret->p=NULL;
173 	ret->q=NULL;
174 	ret->dmp1=NULL;
175 	ret->dmq1=NULL;
176 	ret->iqmp=NULL;
177 	ret->references=1;
178 	ret->_method_mod_n=NULL;
179 	ret->_method_mod_p=NULL;
180 	ret->_method_mod_q=NULL;
181 	ret->blinding=NULL;
182 	ret->bignum_data=NULL;
183 	ret->flags=ret->meth->flags;
184 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_RSA, ret, &ret->ex_data);
185 	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
186 		{
187 #ifndef OPENSSL_NO_ENGINE
188 		if (ret->engine)
189 			ENGINE_finish(ret->engine);
190 #endif
191 		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RSA, ret, &ret->ex_data);
192 		OPENSSL_free(ret);
193 		ret=NULL;
194 		}
195 	return(ret);
196 	}
197 
198 void RSA_free(RSA *r)
199 	{
200 	int i;
201 
202 	if (r == NULL) return;
203 
204 	i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_RSA);
205 #ifdef REF_PRINT
206 	REF_PRINT("RSA",r);
207 #endif
208 	if (i > 0) return;
209 #ifdef REF_CHECK
210 	if (i < 0)
211 		{
212 		fprintf(stderr,"RSA_free, bad reference count\n");
213 		abort();
214 		}
215 #endif
216 
217 	if (r->meth->finish)
218 		r->meth->finish(r);
219 #ifndef OPENSSL_NO_ENGINE
220 	if (r->engine)
221 		ENGINE_finish(r->engine);
222 #endif
223 
224 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RSA, r, &r->ex_data);
225 
226 	if (r->n != NULL) BN_clear_free(r->n);
227 	if (r->e != NULL) BN_clear_free(r->e);
228 	if (r->d != NULL) BN_clear_free(r->d);
229 	if (r->p != NULL) BN_clear_free(r->p);
230 	if (r->q != NULL) BN_clear_free(r->q);
231 	if (r->dmp1 != NULL) BN_clear_free(r->dmp1);
232 	if (r->dmq1 != NULL) BN_clear_free(r->dmq1);
233 	if (r->iqmp != NULL) BN_clear_free(r->iqmp);
234 	if (r->blinding != NULL) BN_BLINDING_free(r->blinding);
235 	if (r->bignum_data != NULL) OPENSSL_free_locked(r->bignum_data);
236 	OPENSSL_free(r);
237 	}
238 
239 int RSA_up_ref(RSA *r)
240 	{
241 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_RSA);
242 #ifdef REF_PRINT
243 	REF_PRINT("RSA",r);
244 #endif
245 #ifdef REF_CHECK
246 	if (i < 2)
247 		{
248 		fprintf(stderr, "RSA_up_ref, bad reference count\n");
249 		abort();
250 		}
251 #endif
252 	return ((i > 1) ? 1 : 0);
253 	}
254 
255 int RSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
256 	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
257         {
258 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_RSA, argl, argp,
259 				new_func, dup_func, free_func);
260         }
261 
262 int RSA_set_ex_data(RSA *r, int idx, void *arg)
263 	{
264 	return(CRYPTO_set_ex_data(&r->ex_data,idx,arg));
265 	}
266 
267 void *RSA_get_ex_data(const RSA *r, int idx)
268 	{
269 	return(CRYPTO_get_ex_data(&r->ex_data,idx));
270 	}
271 
272 int RSA_size(const RSA *r)
273 	{
274 	return(BN_num_bytes(r->n));
275 	}
276 
277 int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
278 	     RSA *rsa, int padding)
279 	{
280 	return(rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding));
281 	}
282 
283 int RSA_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
284 	     RSA *rsa, int padding)
285 	{
286 	return(rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding));
287 	}
288 
289 int RSA_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
290 	     RSA *rsa, int padding)
291 	{
292 	return(rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding));
293 	}
294 
295 int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
296 	     RSA *rsa, int padding)
297 	{
298 	return(rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding));
299 	}
300 
301 int RSA_flags(const RSA *r)
302 	{
303 	return((r == NULL)?0:r->meth->flags);
304 	}
305 
306 void RSA_blinding_off(RSA *rsa)
307 	{
308 	if (rsa->blinding != NULL)
309 		{
310 		BN_BLINDING_free(rsa->blinding);
311 		rsa->blinding=NULL;
312 		}
313 	rsa->flags &= ~RSA_FLAG_BLINDING;
314 	rsa->flags |= RSA_FLAG_NO_BLINDING;
315 	}
316 
317 int RSA_blinding_on(RSA *rsa, BN_CTX *p_ctx)
318 	{
319 	BIGNUM *A,*Ai = NULL;
320 	BN_CTX *ctx;
321 	int ret=0;
322 
323 	if (p_ctx == NULL)
324 		{
325 		if ((ctx=BN_CTX_new()) == NULL) goto err;
326 		}
327 	else
328 		ctx=p_ctx;
329 
330 	/* XXXXX: Shouldn't this be RSA_blinding_off(rsa)? */
331 	if (rsa->blinding != NULL)
332 		{
333 		BN_BLINDING_free(rsa->blinding);
334 		rsa->blinding = NULL;
335 		}
336 
337 	/* NB: similar code appears in setup_blinding (rsa_eay.c);
338 	 * this should be placed in a new function of its own, but for reasons
339 	 * of binary compatibility can't */
340 
341 	BN_CTX_start(ctx);
342 	A = BN_CTX_get(ctx);
343 	if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
344 		{
345 		/* if PRNG is not properly seeded, resort to secret exponent as unpredictable seed */
346 		RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0);
347 		if (!BN_pseudo_rand_range(A,rsa->n)) goto err;
348 		}
349 	else
350 		{
351 		if (!BN_rand_range(A,rsa->n)) goto err;
352 		}
353 	if ((Ai=BN_mod_inverse(NULL,A,rsa->n,ctx)) == NULL) goto err;
354 
355 	if (!rsa->meth->bn_mod_exp(A,A,rsa->e,rsa->n,ctx,rsa->_method_mod_n))
356 		goto err;
357 	if ((rsa->blinding=BN_BLINDING_new(A,Ai,rsa->n)) == NULL) goto err;
358 	/* to make things thread-safe without excessive locking,
359 	 * rsa->blinding will be used just by the current thread: */
360 	rsa->blinding->thread_id = CRYPTO_thread_id();
361 	rsa->flags |= RSA_FLAG_BLINDING;
362 	rsa->flags &= ~RSA_FLAG_NO_BLINDING;
363 	ret=1;
364 err:
365 	if (Ai != NULL) BN_free(Ai);
366 	BN_CTX_end(ctx);
367 	if (ctx != p_ctx) BN_CTX_free(ctx);
368 	return(ret);
369 	}
370 
371 int RSA_memory_lock(RSA *r)
372 	{
373 	int i,j,k,off;
374 	char *p;
375 	BIGNUM *bn,**t[6],*b;
376 	BN_ULONG *ul;
377 
378 	if (r->d == NULL) return(1);
379 	t[0]= &r->d;
380 	t[1]= &r->p;
381 	t[2]= &r->q;
382 	t[3]= &r->dmp1;
383 	t[4]= &r->dmq1;
384 	t[5]= &r->iqmp;
385 	k=sizeof(BIGNUM)*6;
386 	off=k/sizeof(BN_ULONG)+1;
387 	j=1;
388 	for (i=0; i<6; i++)
389 		j+= (*t[i])->top;
390 	if ((p=OPENSSL_malloc_locked((off+j)*sizeof(BN_ULONG))) == NULL)
391 		{
392 		RSAerr(RSA_F_MEMORY_LOCK,ERR_R_MALLOC_FAILURE);
393 		return(0);
394 		}
395 	bn=(BIGNUM *)p;
396 	ul=(BN_ULONG *)&(p[off]);
397 	for (i=0; i<6; i++)
398 		{
399 		b= *(t[i]);
400 		*(t[i])= &(bn[i]);
401 		memcpy((char *)&(bn[i]),(char *)b,sizeof(BIGNUM));
402 		bn[i].flags=BN_FLG_STATIC_DATA;
403 		bn[i].d=ul;
404 		memcpy((char *)ul,b->d,sizeof(BN_ULONG)*b->top);
405 		ul+=b->top;
406 		BN_clear_free(b);
407 		}
408 
409 	/* I should fix this so it can still be done */
410 	r->flags&= ~(RSA_FLAG_CACHE_PRIVATE|RSA_FLAG_CACHE_PUBLIC);
411 
412 	r->bignum_data=p;
413 	return(1);
414 	}
415