diff options
Diffstat (limited to 'openssl/crypto/dsa/dsa_gen.c')
| -rw-r--r-- | openssl/crypto/dsa/dsa_gen.c | 991 |
1 files changed, 687 insertions, 304 deletions
diff --git a/openssl/crypto/dsa/dsa_gen.c b/openssl/crypto/dsa/dsa_gen.c index c398761d0..892003693 100644 --- a/openssl/crypto/dsa/dsa_gen.c +++ b/openssl/crypto/dsa/dsa_gen.c @@ -5,21 +5,21 @@ * 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: @@ -34,10 +34,10 @@ * 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 + * 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 @@ -49,7 +49,7 @@ * 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 @@ -59,313 +59,696 @@ #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() +/* + * 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 +/* + * 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" +# 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" -#ifdef OPENSSL_FIPS -#include <openssl/fips.h> -#endif +# ifdef OPENSSL_FIPS +/* Workaround bug in prototype */ +# define fips_dsa_builtin_paramgen2 fips_dsa_paramgen_bad +# include <openssl/fips.h> +# endif 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) - { -#ifdef OPENSSL_FIPS - if (FIPS_mode() && !(ret->meth->flags & DSA_FLAG_FIPS_METHOD) - && !(ret->flags & DSA_FLAG_NON_FIPS_ALLOW)) - { - DSAerr(DSA_F_DSA_GENERATE_PARAMETERS_EX, DSA_R_NON_FIPS_DSA_METHOD); - return 0; - } -#endif - if(ret->meth->dsa_paramgen) - return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len, - counter_ret, h_ret, cb); -#ifdef OPENSSL_FIPS - else if (FIPS_mode()) - { - return FIPS_dsa_generate_parameters_ex(ret, bits, - seed_in, seed_len, - counter_ret, h_ret, cb); - } -#endif - 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, NULL, counter_ret, h_ret, cb); - } - } + const unsigned char *seed_in, int seed_len, + int *counter_ret, unsigned long *h_ret, + BN_GENCB *cb) +{ +# ifdef OPENSSL_FIPS + if (FIPS_mode() && !(ret->meth->flags & DSA_FLAG_FIPS_METHOD) + && !(ret->flags & DSA_FLAG_NON_FIPS_ALLOW)) { + DSAerr(DSA_F_DSA_GENERATE_PARAMETERS_EX, DSA_R_NON_FIPS_DSA_METHOD); + return 0; + } +# endif + if (ret->meth->dsa_paramgen) + return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len, + counter_ret, h_ret, cb); +# ifdef OPENSSL_FIPS + else if (FIPS_mode()) { + return FIPS_dsa_generate_parameters_ex(ret, bits, + seed_in, seed_len, + counter_ret, h_ret, cb); + } +# endif + 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, NULL, 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, - unsigned char *seed_out, - 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 */ - if (!EVP_Digest(seed, qsize, md, NULL, evpmd, NULL)) - goto err; - if (!EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL)) - goto err; - 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; - } - - if (!EVP_Digest(buf, qsize, md ,NULL, evpmd, - NULL)) - goto err; - - /* 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 (seed_out) - memcpy(seed_out, seed, qsize); - } - if(ctx) - { - BN_CTX_end(ctx); - BN_CTX_free(ctx); - } - if (mont != NULL) BN_MONT_CTX_free(mont); - return ok; - } + const EVP_MD *evpmd, const unsigned char *seed_in, + size_t seed_len, unsigned char *seed_out, + 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 */ + if (!EVP_Digest(seed, qsize, md, NULL, evpmd, NULL)) + goto err; + if (!EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL)) + goto err; + 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; + } + + if (!EVP_Digest(buf, qsize, md, NULL, evpmd, NULL)) + goto err; + + /* 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 (seed_out) + memcpy(seed_out, seed, qsize); + } + if (ctx) { + BN_CTX_end(ctx); + BN_CTX_free(ctx); + } + if (mont != NULL) + BN_MONT_CTX_free(mont); + return ok; +} + +# ifdef OPENSSL_FIPS +# undef fips_dsa_builtin_paramgen2 +extern int fips_dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N, + const EVP_MD *evpmd, + const unsigned char *seed_in, + size_t seed_len, int idx, + unsigned char *seed_out, + int *counter_ret, unsigned long *h_ret, + BN_GENCB *cb); +# endif + +/* + * This is a parameter generation algorithm for the DSA2 algorithm as + * described in FIPS 186-3. + */ + +int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N, + const EVP_MD *evpmd, const unsigned char *seed_in, + size_t seed_len, int idx, unsigned char *seed_out, + int *counter_ret, unsigned long *h_ret, + BN_GENCB *cb) +{ + int ok = -1; + unsigned char *seed = NULL, *seed_tmp = NULL; + unsigned char md[EVP_MAX_MD_SIZE]; + int mdsize; + 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 = N >> 3; + int counter = 0; + int r = 0; + BN_CTX *ctx = NULL; + EVP_MD_CTX mctx; + unsigned int h = 2; + +# ifdef OPENSSL_FIPS + + if (FIPS_mode()) + return fips_dsa_builtin_paramgen2(ret, L, N, evpmd, + seed_in, seed_len, idx, + seed_out, counter_ret, h_ret, cb); +# endif + + EVP_MD_CTX_init(&mctx); + + if (evpmd == NULL) { + if (N == 160) + evpmd = EVP_sha1(); + else if (N == 224) + evpmd = EVP_sha224(); + else + evpmd = EVP_sha256(); + } + + mdsize = EVP_MD_size(evpmd); + /* If unverificable g generation only don't need seed */ + if (!ret->p || !ret->q || idx >= 0) { + if (seed_len == 0) + seed_len = mdsize; + + seed = OPENSSL_malloc(seed_len); + + if (seed_out) + seed_tmp = seed_out; + else + seed_tmp = OPENSSL_malloc(seed_len); + + if (!seed || !seed_tmp) + goto err; + + if (seed_in) + 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); + X = BN_CTX_get(ctx); + c = BN_CTX_get(ctx); + test = BN_CTX_get(ctx); + + /* if p, q already supplied generate g only */ + if (ret->p && ret->q) { + p = ret->p; + q = ret->q; + if (idx >= 0) + memcpy(seed_tmp, seed, seed_len); + goto g_only; + } else { + p = BN_CTX_get(ctx); + q = BN_CTX_get(ctx); + } + + if (!BN_lshift(test, BN_value_one(), L - 1)) + goto err; + for (;;) { + for (;;) { /* find q */ + unsigned char *pmd; + /* step 1 */ + if (!BN_GENCB_call(cb, 0, m++)) + goto err; + + if (!seed_in) { + if (RAND_pseudo_bytes(seed, seed_len) < 0) + goto err; + } + /* step 2 */ + if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL)) + goto err; + /* Take least significant bits of md */ + if (mdsize > qsize) + pmd = md + mdsize - qsize; + else + pmd = md; + + if (mdsize < qsize) + memset(md + mdsize, 0, qsize - mdsize); + + /* step 3 */ + pmd[0] |= 0x80; + pmd[qsize - 1] |= 0x01; + if (!BN_bin2bn(pmd, qsize, q)) + goto err; + + /* step 4 */ + r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx, + seed_in ? 1 : 0, cb); + if (r > 0) + break; + if (r != 0) + goto err; + /* Provided seed didn't produce a prime: error */ + if (seed_in) { + ok = 0; + DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_Q_NOT_PRIME); + goto err; + } + + /* do a callback call */ + /* step 5 */ + } + /* Copy seed to seed_out before we mess with it */ + if (seed_out) + memcpy(seed_out, seed, seed_len); + + if (!BN_GENCB_call(cb, 2, 0)) + goto err; + if (!BN_GENCB_call(cb, 3, 0)) + goto err; + + /* step 6 */ + counter = 0; + /* "offset = 1" */ + + n = (L - 1) / (mdsize << 3); + + 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 = seed_len - 1; i >= 0; i--) { + seed[i]++; + if (seed[i] != 0) + break; + } + + if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL)) + goto err; + + /* step 8 */ + if (!BN_bin2bn(md, mdsize, r0)) + goto err; + if (!BN_lshift(r0, r0, (mdsize << 3) * k)) + goto err; + if (!BN_add(W, W, r0)) + goto err; + } + + /* more of step 8 */ + if (!BN_mask_bits(W, L - 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 >= (int)(4 * L)) + break; + } + if (seed_in) { + ok = 0; + DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS); + goto err; + } + } + end: + if (!BN_GENCB_call(cb, 2, 1)) + goto err; + + g_only: + + /* 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 (idx < 0) { + if (!BN_set_word(test, h)) + goto err; + } else + h = 1; + if (!BN_MONT_CTX_set(mont, p, ctx)) + goto err; + + for (;;) { + static const unsigned char ggen[4] = { 0x67, 0x67, 0x65, 0x6e }; + if (idx >= 0) { + md[0] = idx & 0xff; + md[1] = (h >> 8) & 0xff; + md[2] = h & 0xff; + if (!EVP_DigestInit_ex(&mctx, evpmd, NULL)) + goto err; + if (!EVP_DigestUpdate(&mctx, seed_tmp, seed_len)) + goto err; + if (!EVP_DigestUpdate(&mctx, ggen, sizeof(ggen))) + goto err; + if (!EVP_DigestUpdate(&mctx, md, 3)) + goto err; + if (!EVP_DigestFinal_ex(&mctx, md, NULL)) + goto err; + if (!BN_bin2bn(md, mdsize, test)) + goto err; + } + /* g=test^r0%p */ + if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont)) + goto err; + if (!BN_is_one(g)) + break; + if (idx < 0 && !BN_add(test, test, BN_value_one())) + goto err; + h++; + if (idx >= 0 && h > 0xffff) + goto err; + } + + if (!BN_GENCB_call(cb, 3, 1)) + goto err; + + ok = 1; + err: + if (ok == 1) { + if (p != ret->p) { + if (ret->p) + BN_free(ret->p); + ret->p = BN_dup(p); + } + if (q != ret->q) { + if (ret->q) + BN_free(ret->q); + ret->q = BN_dup(q); + } + if (ret->g) + BN_free(ret->g); + ret->g = BN_dup(g); + if (ret->p == NULL || ret->q == NULL || ret->g == NULL) { + ok = -1; + goto err; + } + if (counter_ret != NULL) + *counter_ret = counter; + if (h_ret != NULL) + *h_ret = h; + } + if (seed) + OPENSSL_free(seed); + if (seed_out != seed_tmp) + OPENSSL_free(seed_tmp); + if (ctx) { + BN_CTX_end(ctx); + BN_CTX_free(ctx); + } + if (mont != NULL) + BN_MONT_CTX_free(mont); + EVP_MD_CTX_cleanup(&mctx); + return ok; +} + +int dsa_paramgen_check_g(DSA *dsa) +{ + BN_CTX *ctx; + BIGNUM *tmp; + BN_MONT_CTX *mont = NULL; + int rv = -1; + ctx = BN_CTX_new(); + if (!ctx) + return -1; + BN_CTX_start(ctx); + if (BN_cmp(dsa->g, BN_value_one()) <= 0) + return 0; + if (BN_cmp(dsa->g, dsa->p) >= 0) + return 0; + tmp = BN_CTX_get(ctx); + if (!tmp) + goto err; + if ((mont = BN_MONT_CTX_new()) == NULL) + goto err; + if (!BN_MONT_CTX_set(mont, dsa->p, ctx)) + goto err; + /* Work out g^q mod p */ + if (!BN_mod_exp_mont(tmp, dsa->g, dsa->q, dsa->p, ctx, mont)) + goto err; + if (!BN_cmp(tmp, BN_value_one())) + rv = 1; + else + rv = 0; + err: + BN_CTX_end(ctx); + if (mont) + BN_MONT_CTX_free(mont); + BN_CTX_free(ctx); + return rv; + +} #endif |