1 /* crypto/rsa/rsa_eay.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
61 #include <openssl/bn.h>
62 #include <openssl/rsa.h>
63 #include <openssl/rand.h>
64 #ifndef OPENSSL_NO_ENGINE
65 #include <openssl/engine.h>
70 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
71 unsigned char *to, RSA *rsa,int padding);
72 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
73 unsigned char *to, RSA *rsa,int padding);
74 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
75 unsigned char *to, RSA *rsa,int padding);
76 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
77 unsigned char *to, RSA *rsa,int padding);
78 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa);
79 static int RSA_eay_init(RSA *rsa);
80 static int RSA_eay_finish(RSA *rsa);
81 static RSA_METHOD rsa_pkcs1_eay_meth={
82 "Eric Young's PKCS#1 RSA",
83 RSA_eay_public_encrypt,
84 RSA_eay_public_decrypt, /* signature verification */
85 RSA_eay_private_encrypt, /* signing */
86 RSA_eay_private_decrypt,
88 BN_mod_exp_mont, /* XXX probably we should not use Montgomery if e == 3 */
98 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
100 return(&rsa_pkcs1_eay_meth);
103 /* Static helper to reduce oodles of code duplication. As a slight
104 * optimisation, the "MONT_HELPER() macro must be used as front-end to this
105 * function, to prevent unnecessary function calls - there is an initial test
106 * that is performed by the macro-generated code. */
107 static int rsa_eay_mont_helper(BN_MONT_CTX **ptr, const BIGNUM *modulus, BN_CTX *ctx)
109 BN_MONT_CTX *bn_mont_ctx;
110 if((bn_mont_ctx = BN_MONT_CTX_new()) == NULL)
112 if(!BN_MONT_CTX_set(bn_mont_ctx, modulus, ctx))
114 BN_MONT_CTX_free(bn_mont_ctx);
117 if (*ptr == NULL) /* other thread may have finished first */
119 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
120 if (*ptr == NULL) /* check again in the lock to stop races */
125 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
128 BN_MONT_CTX_free(bn_mont_ctx);
132 * MONT_HELPER(rsa, bn_ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
134 #define MONT_HELPER(rsa, ctx, m, pre_cond, err_instr) \
135 if((pre_cond) && ((rsa)->_method_mod_##m == NULL) && \
136 !rsa_eay_mont_helper(&((rsa)->_method_mod_##m), \
140 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
141 unsigned char *to, RSA *rsa, int padding)
144 int i,j,k,num=0,r= -1;
145 unsigned char *buf=NULL;
150 if ((ctx=BN_CTX_new()) == NULL) goto err;
151 num=BN_num_bytes(rsa->n);
152 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
154 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
160 case RSA_PKCS1_PADDING:
161 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
163 #ifndef OPENSSL_NO_SHA
164 case RSA_PKCS1_OAEP_PADDING:
165 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
168 case RSA_SSLV23_PADDING:
169 i=RSA_padding_add_SSLv23(buf,num,from,flen);
172 i=RSA_padding_add_none(buf,num,from,flen);
175 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
178 if (i <= 0) goto err;
180 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
182 if (BN_ucmp(&f, rsa->n) >= 0)
184 /* usually the padding functions would catch this */
185 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
189 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
191 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
192 rsa->_method_mod_n)) goto err;
194 /* put in leading 0 bytes if the number is less than the
195 * length of the modulus */
196 j=BN_num_bytes(&ret);
197 i=BN_bn2bin(&ret,&(to[num-j]));
198 for (k=0; k<(num-i); k++)
203 if (ctx != NULL) BN_CTX_free(ctx);
208 OPENSSL_cleanse(buf,num);
215 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
216 unsigned char *to, RSA *rsa, int padding)
219 int i,j,k,num=0,r= -1;
220 unsigned char *buf=NULL;
226 if ((ctx=BN_CTX_new()) == NULL) goto err;
227 num=BN_num_bytes(rsa->n);
228 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
230 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
236 case RSA_PKCS1_PADDING:
237 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
240 i=RSA_padding_add_none(buf,num,from,flen);
242 case RSA_SSLV23_PADDING:
244 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
247 if (i <= 0) goto err;
249 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
251 if (BN_ucmp(&f, rsa->n) >= 0)
253 /* usually the padding functions would catch this */
254 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
258 if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
259 RSA_blinding_on(rsa,ctx);
260 if (rsa->flags & RSA_FLAG_BLINDING)
261 if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) goto err;
263 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
266 (rsa->dmp1 != NULL) &&
267 (rsa->dmq1 != NULL) &&
268 (rsa->iqmp != NULL)) )
269 { if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
272 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,NULL)) goto err;
275 if (rsa->flags & RSA_FLAG_BLINDING)
276 if (!BN_BLINDING_invert(&ret,rsa->blinding,ctx)) goto err;
278 /* put in leading 0 bytes if the number is less than the
279 * length of the modulus */
280 j=BN_num_bytes(&ret);
281 i=BN_bn2bin(&ret,&(to[num-j]));
282 for (k=0; k<(num-i); k++)
287 if (ctx != NULL) BN_CTX_free(ctx);
292 OPENSSL_cleanse(buf,num);
298 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
299 unsigned char *to, RSA *rsa, int padding)
304 unsigned char *buf=NULL;
310 if (ctx == NULL) goto err;
312 num=BN_num_bytes(rsa->n);
314 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
316 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
320 /* This check was for equality but PGP does evil things
321 * and chops off the top '0' bytes */
324 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
328 /* make data into a big number */
329 if (BN_bin2bn(from,(int)flen,&f) == NULL) goto err;
331 if (BN_ucmp(&f, rsa->n) >= 0)
333 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
337 if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
338 RSA_blinding_on(rsa,ctx);
339 if (rsa->flags & RSA_FLAG_BLINDING)
340 if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) goto err;
343 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
346 (rsa->dmp1 != NULL) &&
347 (rsa->dmq1 != NULL) &&
348 (rsa->iqmp != NULL)) )
349 { if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
352 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,NULL))
356 if (rsa->flags & RSA_FLAG_BLINDING)
357 if (!BN_BLINDING_invert(&ret,rsa->blinding,ctx)) goto err;
360 j=BN_bn2bin(&ret,p); /* j is only used with no-padding mode */
364 case RSA_PKCS1_PADDING:
365 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
367 #ifndef OPENSSL_NO_SHA
368 case RSA_PKCS1_OAEP_PADDING:
369 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
372 case RSA_SSLV23_PADDING:
373 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
376 r=RSA_padding_check_none(to,num,buf,j,num);
379 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
383 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
386 if (ctx != NULL) BN_CTX_free(ctx);
391 OPENSSL_cleanse(buf,num);
397 /* signature verification */
398 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
399 unsigned char *to, RSA *rsa, int padding)
404 unsigned char *buf=NULL;
410 if (ctx == NULL) goto err;
412 num=BN_num_bytes(rsa->n);
413 buf=(unsigned char *)OPENSSL_malloc(num);
416 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
420 /* This check was for equality but PGP does evil things
421 * and chops off the top '0' bytes */
424 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
428 if (BN_bin2bn(from,flen,&f) == NULL) goto err;
430 if (BN_ucmp(&f, rsa->n) >= 0)
432 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
436 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
438 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
439 rsa->_method_mod_n)) goto err;
446 case RSA_PKCS1_PADDING:
447 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
450 r=RSA_padding_check_none(to,num,buf,i,num);
453 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
457 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
460 if (ctx != NULL) BN_CTX_free(ctx);
465 OPENSSL_cleanse(buf,num);
471 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
480 if ((ctx=BN_CTX_new()) == NULL) goto err;
482 MONT_HELPER(rsa, ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
483 MONT_HELPER(rsa, ctx, q, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
484 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
486 if (!BN_mod(&r1,I,rsa->q,ctx)) goto err;
487 if (!rsa->meth->bn_mod_exp(&m1,&r1,rsa->dmq1,rsa->q,ctx,
488 rsa->_method_mod_q)) goto err;
490 if (!BN_mod(&r1,I,rsa->p,ctx)) goto err;
491 if (!rsa->meth->bn_mod_exp(r0,&r1,rsa->dmp1,rsa->p,ctx,
492 rsa->_method_mod_p)) goto err;
494 if (!BN_sub(r0,r0,&m1)) goto err;
495 /* This will help stop the size of r0 increasing, which does
496 * affect the multiply if it optimised for a power of 2 size */
498 if (!BN_add(r0,r0,rsa->p)) goto err;
500 if (!BN_mul(&r1,r0,rsa->iqmp,ctx)) goto err;
501 if (!BN_mod(r0,&r1,rsa->p,ctx)) goto err;
502 /* If p < q it is occasionally possible for the correction of
503 * adding 'p' if r0 is negative above to leave the result still
504 * negative. This can break the private key operations: the following
505 * second correction should *always* correct this rare occurrence.
506 * This will *never* happen with OpenSSL generated keys because
507 * they ensure p > q [steve]
510 if (!BN_add(r0,r0,rsa->p)) goto err;
511 if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;
512 if (!BN_add(r0,&r1,&m1)) goto err;
514 if (rsa->e && rsa->n)
516 if (!rsa->meth->bn_mod_exp(&vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
517 /* If 'I' was greater than (or equal to) rsa->n, the operation
518 * will be equivalent to using 'I mod n'. However, the result of
519 * the verify will *always* be less than 'n' so we don't check
520 * for absolute equality, just congruency. */
521 if (!BN_sub(&vrfy, &vrfy, I)) goto err;
522 if (!BN_mod(&vrfy, &vrfy, rsa->n, ctx)) goto err;
523 if (BN_get_sign(&vrfy))
524 if (!BN_add(&vrfy, &vrfy, rsa->n)) goto err;
525 if (!BN_is_zero(&vrfy))
526 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
527 * miscalculated CRT output, just do a raw (slower)
528 * mod_exp and return that instead. */
529 if (!rsa->meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,NULL)) goto err;
535 BN_clear_free(&vrfy);
540 static int RSA_eay_init(RSA *rsa)
542 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
546 static int RSA_eay_finish(RSA *rsa)
548 if (rsa->_method_mod_n != NULL)
549 BN_MONT_CTX_free(rsa->_method_mod_n);
550 if (rsa->_method_mod_p != NULL)
551 BN_MONT_CTX_free(rsa->_method_mod_p);
552 if (rsa->_method_mod_q != NULL)
553 BN_MONT_CTX_free(rsa->_method_mod_q);