diff options
author | Arne Schwabe <arne@rfc2549.org> | 2012-04-16 19:21:14 +0200 |
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committer | Arne Schwabe <arne@rfc2549.org> | 2012-04-16 19:21:14 +0200 |
commit | 3e4d8f433239c40311037616b1b8833a06651ae0 (patch) | |
tree | 98ab7fce0d011d34677b0beb762d389cb5c39199 /openssl/crypto/dsa/dsa_gen.c |
Initial import
Diffstat (limited to 'openssl/crypto/dsa/dsa_gen.c')
-rw-r--r-- | openssl/crypto/dsa/dsa_gen.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/openssl/crypto/dsa/dsa_gen.c b/openssl/crypto/dsa/dsa_gen.c new file mode 100644 index 00000000..cb0b4538 --- /dev/null +++ b/openssl/crypto/dsa/dsa_gen.c @@ -0,0 +1,344 @@ +/* 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 EVP_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 EVP_sha1() +#endif + +#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */ + +#ifndef OPENSSL_NO_SHA + +#include <stdio.h> +#include "cryptlib.h" +#include <openssl/evp.h> +#include <openssl/bn.h> +#include <openssl/rand.h> +#include <openssl/sha.h> +#include "dsa_locl.h" + +int DSA_generate_parameters_ex(DSA *ret, int bits, + const unsigned char *seed_in, int seed_len, + int *counter_ret, unsigned long *h_ret, BN_GENCB *cb) + { + if(ret->meth->dsa_paramgen) + return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len, + counter_ret, h_ret, cb); + else + { + const EVP_MD *evpmd; + size_t qbits = bits >= 2048 ? 256 : 160; + + if (bits >= 2048) + { + qbits = 256; + evpmd = EVP_sha256(); + } + else + { + qbits = 160; + evpmd = EVP_sha1(); + } + + return dsa_builtin_paramgen(ret, bits, qbits, evpmd, + seed_in, seed_len, counter_ret, h_ret, cb); + } + } + +int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits, + const EVP_MD *evpmd, const unsigned char *seed_in, size_t seed_len, + int *counter_ret, unsigned long *h_ret, BN_GENCB *cb) + { + int ok=0; + unsigned char seed[SHA256_DIGEST_LENGTH]; + unsigned char md[SHA256_DIGEST_LENGTH]; + unsigned char buf[SHA256_DIGEST_LENGTH],buf2[SHA256_DIGEST_LENGTH]; + BIGNUM *r0,*W,*X,*c,*test; + BIGNUM *g=NULL,*q=NULL,*p=NULL; + BN_MONT_CTX *mont=NULL; + int i, k, n=0, m=0, qsize = qbits >> 3; + int counter=0; + int r=0; + BN_CTX *ctx=NULL; + unsigned int h=2; + + if (qsize != SHA_DIGEST_LENGTH && qsize != SHA224_DIGEST_LENGTH && + qsize != SHA256_DIGEST_LENGTH) + /* invalid q size */ + return 0; + + if (evpmd == NULL) + /* use SHA1 as default */ + evpmd = EVP_sha1(); + + if (bits < 512) + bits = 512; + + bits = (bits+63)/64*64; + + /* NB: seed_len == 0 is special case: copy generated seed to + * seed_in if it is not NULL. + */ + if (seed_len && (seed_len < (size_t)qsize)) + seed_in = NULL; /* seed buffer too small -- ignore */ + if (seed_len > (size_t)qsize) + seed_len = qsize; /* App. 2.2 of FIPS PUB 186 allows larger SEED, + * but our internal buffers are restricted to 160 bits*/ + if (seed_in != NULL) + memcpy(seed, seed_in, seed_len); + + if ((ctx=BN_CTX_new()) == NULL) + goto err; + + if ((mont=BN_MONT_CTX_new()) == NULL) + goto err; + + BN_CTX_start(ctx); + r0 = BN_CTX_get(ctx); + g = BN_CTX_get(ctx); + W = BN_CTX_get(ctx); + q = BN_CTX_get(ctx); + X = BN_CTX_get(ctx); + c = BN_CTX_get(ctx); + p = BN_CTX_get(ctx); + test = BN_CTX_get(ctx); + + if (!BN_lshift(test,BN_value_one(),bits-1)) + goto err; + + for (;;) + { + for (;;) /* find q */ + { + int seed_is_random; + + /* step 1 */ + if(!BN_GENCB_call(cb, 0, m++)) + goto err; + + if (!seed_len) + { + RAND_pseudo_bytes(seed, qsize); + 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, qsize); + memcpy(buf2, seed, qsize); + /* precompute "SEED + 1" for step 7: */ + for (i = qsize-1; i >= 0; i--) + { + buf[i]++; + if (buf[i] != 0) + break; + } + + /* step 2 */ + EVP_Digest(seed, qsize, md, NULL, evpmd, NULL); + EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL); + for (i = 0; i < qsize; i++) + md[i]^=buf2[i]; + + /* step 3 */ + md[0] |= 0x80; + md[qsize-1] |= 0x01; + if (!BN_bin2bn(md, qsize, q)) + goto err; + + /* step 4 */ + r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx, + seed_is_random, cb); + if (r > 0) + break; + if (r != 0) + goto err; + + /* do a callback call */ + /* step 5 */ + } + + if(!BN_GENCB_call(cb, 2, 0)) goto err; + if(!BN_GENCB_call(cb, 3, 0)) goto err; + + /* step 6 */ + counter=0; + /* "offset = 2" */ + + n=(bits-1)/160; + + for (;;) + { + if ((counter != 0) && !BN_GENCB_call(cb, 0, counter)) + goto err; + + /* 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 = qsize-1; i >= 0; i--) + { + buf[i]++; + if (buf[i] != 0) + break; + } + + EVP_Digest(buf, qsize, md ,NULL, evpmd, NULL); + + /* step 8 */ + if (!BN_bin2bn(md, qsize, r0)) + goto err; + if (!BN_lshift(r0,r0,(qsize << 3)*k)) goto err; + if (!BN_add(W,W,r0)) goto err; + } + + /* more of step 8 */ + if (!BN_mask_bits(W,bits-1)) goto err; + if (!BN_copy(X,W)) goto err; + if (!BN_add(X,X,test)) goto err; + + /* step 9 */ + if (!BN_lshift1(r0,q)) goto err; + if (!BN_mod(c,X,r0,ctx)) goto err; + if (!BN_sub(r0,c,BN_value_one())) goto err; + if (!BN_sub(p,X,r0)) goto err; + + /* step 10 */ + if (BN_cmp(p,test) >= 0) + { + /* step 11 */ + r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, + ctx, 1, cb); + 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(!BN_GENCB_call(cb, 2, 1)) + goto err; + + /* We now need to generate g */ + /* Set r0=(p-1)/q */ + if (!BN_sub(test,p,BN_value_one())) goto err; + if (!BN_div(r0,NULL,test,q,ctx)) goto err; + + if (!BN_set_word(test,h)) goto err; + if (!BN_MONT_CTX_set(mont,p,ctx)) goto err; + + for (;;) + { + /* g=test^r0%p */ + if (!BN_mod_exp_mont(g,test,r0,p,ctx,mont)) goto err; + if (!BN_is_one(g)) break; + if (!BN_add(test,test,BN_value_one())) goto err; + h++; + } + + if(!BN_GENCB_call(cb, 3, 1)) + goto err; + + ok=1; +err: + if (ok) + { + if(ret->p) BN_free(ret->p); + if(ret->q) BN_free(ret->q); + if(ret->g) BN_free(ret->g); + ret->p=BN_dup(p); + ret->q=BN_dup(q); + ret->g=BN_dup(g); + if (ret->p == NULL || ret->q == NULL || ret->g == NULL) + { + ok=0; + goto err; + } + if (counter_ret != NULL) *counter_ret=counter; + if (h_ret != NULL) *h_ret=h; + } + if(ctx) + { + BN_CTX_end(ctx); + BN_CTX_free(ctx); + } + if (mont != NULL) BN_MONT_CTX_free(mont); + return ok; + } +#endif |