/* * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved. * * The contents of this file constitute Original Code as defined in and are * subject to the Apple Public Source License Version 1.2 (the 'License'). * You may not use this file except in compliance with the License. Please obtain * a copy of the License at http://www.apple.com/publicsource and read it before * using this file. * * This Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the * specific language governing rights and limitations under the License. */ /* crypto/dsa/dsa_gen.c */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ #undef GENUINE_DSA #ifdef GENUINE_DSA /* Parameter generation follows the original release of FIPS PUB 186, * Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180) */ #define HASH SHA #else /* Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186, * also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in * FIPS PUB 180-1) */ #define HASH SHA1 #endif #ifndef NO_SHA #include <stdio.h> #include <time.h> #include "cryptlib.h" #include <openssl/sha.h> #include <openssl/bn.h> #include <openssl/dsa.h> #include <openssl/rand.h> DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len, int *counter_ret, unsigned long *h_ret, void (*callback)(int, int, void *), void *cb_arg) { int ok=0; unsigned char seed[SHA_DIGEST_LENGTH]; unsigned char md[SHA_DIGEST_LENGTH]; unsigned char buf[SHA_DIGEST_LENGTH],buf2[SHA_DIGEST_LENGTH]; BIGNUM *r0,*W,*X,*c,*test; BIGNUM *g=NULL,*q=NULL,*p=NULL; BN_MONT_CTX *mont=NULL; int k,n=0,i,b,m=0; int counter=0; int r=0; BN_CTX *ctx=NULL,*ctx2=NULL,*ctx3=NULL; unsigned int h=2; DSA *ret=NULL; if (bits < 512) bits=512; bits=(bits+63)/64*64; if (seed_len < 20) seed_in = NULL; /* seed buffer too small -- ignore */ if (seed_len > 20) seed_len = 20; /* App. 2.2 of FIPS PUB 186 allows larger SEED, * but our internal buffers are restricted to 160 bits*/ if ((seed_in != NULL) && (seed_len == 20)) memcpy(seed,seed_in,seed_len); if ((ctx=BN_CTX_new()) == NULL) goto err; if ((ctx2=BN_CTX_new()) == NULL) goto err; if ((ctx3=BN_CTX_new()) == NULL) goto err; if ((ret=DSA_new()) == NULL) goto err; if ((mont=BN_MONT_CTX_new()) == NULL) goto err; BN_CTX_start(ctx2); r0 = BN_CTX_get(ctx2); g = BN_CTX_get(ctx2); W = BN_CTX_get(ctx2); q = BN_CTX_get(ctx2); X = BN_CTX_get(ctx2); c = BN_CTX_get(ctx2); p = BN_CTX_get(ctx2); test = BN_CTX_get(ctx2); BN_lshift(test,BN_value_one(),bits-1); for (;;) { for (;;) /* find q */ { int seed_is_random; /* step 1 */ if (callback != NULL) callback(0,m++,cb_arg); if (!seed_len) { RAND_pseudo_bytes(seed,SHA_DIGEST_LENGTH); seed_is_random = 1; } else { seed_is_random = 0; seed_len=0; /* use random seed if 'seed_in' turns out to be bad*/ } memcpy(buf,seed,SHA_DIGEST_LENGTH); memcpy(buf2,seed,SHA_DIGEST_LENGTH); /* precompute "SEED + 1" for step 7: */ for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--) { buf[i]++; if (buf[i] != 0) break; } /* step 2 */ HASH(seed,SHA_DIGEST_LENGTH,md); HASH(buf,SHA_DIGEST_LENGTH,buf2); for (i=0; i<SHA_DIGEST_LENGTH; i++) md[i]^=buf2[i]; /* step 3 */ md[0]|=0x80; md[SHA_DIGEST_LENGTH-1]|=0x01; if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) goto err; /* step 4 */ r = BN_is_prime_fasttest(q, DSS_prime_checks, callback, ctx3, cb_arg, seed_is_random); if (r > 0) break; if (r != 0) goto err; /* do a callback call */ /* step 5 */ } if (callback != NULL) callback(2,0,cb_arg); if (callback != NULL) callback(3,0,cb_arg); /* step 6 */ counter=0; /* "offset = 2" */ n=(bits-1)/160; b=(bits-1)-n*160; for (;;) { if (callback != NULL && counter != 0) callback(0,counter,cb_arg); /* step 7 */ BN_zero(W); /* now 'buf' contains "SEED + offset - 1" */ for (k=0; k<=n; k++) { /* obtain "SEED + offset + k" by incrementing: */ for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--) { buf[i]++; if (buf[i] != 0) break; } HASH(buf,SHA_DIGEST_LENGTH,md); /* step 8 */ if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0)) goto err; BN_lshift(r0,r0,160*k); BN_add(W,W,r0); } /* more of step 8 */ BN_mask_bits(W,bits-1); BN_copy(X,W); /* this should be ok */ BN_add(X,X,test); /* this should be ok */ /* step 9 */ BN_lshift1(r0,q); BN_mod(c,X,r0,ctx); BN_sub(r0,c,BN_value_one()); BN_sub(p,X,r0); /* step 10 */ if (BN_cmp(p,test) >= 0) { /* step 11 */ r = BN_is_prime_fasttest(p, DSS_prime_checks, callback, ctx3, cb_arg, 1); if (r > 0) goto end; /* found it */ if (r != 0) goto err; } /* step 13 */ counter++; /* "offset = offset + n + 1" */ /* step 14 */ if (counter >= 4096) break; } } end: if (callback != NULL) callback(2,1,cb_arg); /* We now need to generate g */ /* Set r0=(p-1)/q */ BN_sub(test,p,BN_value_one()); BN_div(r0,NULL,test,q,ctx); BN_set_word(test,h); BN_MONT_CTX_set(mont,p,ctx); for (;;) { /* g=test^r0%p */ BN_mod_exp_mont(g,test,r0,p,ctx,mont); if (!BN_is_one(g)) break; BN_add(test,test,BN_value_one()); h++; } if (callback != NULL) callback(3,1,cb_arg); ok=1; err: if (!ok) { if (ret != NULL) DSA_free(ret); } else { ret->p=BN_dup(p); ret->q=BN_dup(q); ret->g=BN_dup(g); if ((m > 1) && (seed_in != NULL)) memcpy(seed_in,seed,20); if (counter_ret != NULL) *counter_ret=counter; if (h_ret != NULL) *h_ret=h; } if (ctx != NULL) BN_CTX_free(ctx); if (ctx2 != NULL) { BN_CTX_end(ctx2); BN_CTX_free(ctx2); } if (ctx3 != NULL) BN_CTX_free(ctx3); if (mont != NULL) BN_MONT_CTX_free(mont); return(ok?ret:NULL); } #endif