X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fdsa%2Fdsa_gen.c;h=710a4faa66bd996d0d559d48246607b5337644dd;hp=8202b80292ab32fe6c679ff33eed5f841615a264;hb=7865b871c0307ad2d71a8f3dc066b7cfd0d99c4a;hpb=31b8d8684441e6cd5138832bb1b2ddb10acd6ba6 diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c index 8202b80292..710a4faa66 100644 --- a/crypto/dsa/dsa_gen.c +++ b/crypto/dsa/dsa_gen.c @@ -59,28 +59,29 @@ #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 #include #include "cryptlib.h" -#include "sha.h" -#include "bn.h" -#include "dsa.h" -#include "rand.h" - -DSA *DSA_generate_parameters(bits,seed_in,seed_len,counter_ret,h_ret,callback, - cb_arg) -int bits; -unsigned char *seed_in; -int seed_len; -int *counter_ret; -unsigned long *h_ret; -void (*callback)(); -char *cb_arg; +#include +#include +#include +#include + +DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len, + int *counter_ret, unsigned long *h_ret, void (*callback)(), + void *cb_arg) { int ok=0; unsigned char seed[SHA_DIGEST_LENGTH]; @@ -91,18 +92,26 @@ char *cb_arg; BN_MONT_CTX *mont=NULL; int k,n=0,i,b,m=0; int counter=0; - BN_CTX *ctx=NULL,*ctx2=NULL; + int r=0; + BN_CTX *ctx=NULL,*ctx2=NULL,*ctx3=NULL,*ctx4=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 ((ctx4=BN_CTX_new()) == NULL) goto err; if ((ret=DSA_new()) == NULL) goto err; if ((mont=BN_MONT_CTX_new()) == NULL) goto err; @@ -120,18 +129,26 @@ char *cb_arg; for (;;) { - for (;;) + for (;;) /* find q */ { + int seed_is_random; + /* step 1 */ if (callback != NULL) callback(0,m++,cb_arg); if (!seed_len) - RAND_bytes(seed,SHA_DIGEST_LENGTH); + { + RAND_pseudo_bytes(seed,SHA_DIGEST_LENGTH); + seed_is_random = 1; + } else - seed_len=0; - + { + 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]++; @@ -147,10 +164,15 @@ char *cb_arg; /* step 3 */ md[0]|=0x80; md[SHA_DIGEST_LENGTH-1]|=0x01; - if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) abort(); + if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) goto err; /* step 4 */ - if (DSA_is_prime(q,callback,cb_arg) > 0) break; + r = BN_is_prime_fasttest(q, DSS_prime_checks, callback, ctx3, ctx4, cb_arg, seed_is_random); + if (r > 0) + break; + if (r != 0) + goto err; + /* do a callback call */ /* step 5 */ } @@ -160,16 +182,22 @@ char *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]++; @@ -179,7 +207,8 @@ char *cb_arg; HASH(buf,SHA_DIGEST_LENGTH,md); /* step 8 */ - if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0)) abort(); + if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0)) + goto err; BN_lshift(r0,r0,160*k); BN_add(W,W,r0); } @@ -199,26 +228,28 @@ char *cb_arg; if (BN_cmp(p,test) >= 0) { /* step 11 */ - if (DSA_is_prime(p,callback,cb_arg) > 0) - goto end; + r = BN_is_prime_fasttest(p, DSS_prime_checks, callback, ctx3, ctx4, 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; - - if (callback != NULL) callback(0,counter,cb_arg); } } end: if (callback != NULL) callback(2,1,cb_arg); - /* We now need to gernerate g */ + /* 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_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); @@ -250,91 +281,10 @@ err: if (h_ret != NULL) *h_ret=h; } if (ctx != NULL) BN_CTX_free(ctx); - if (ctx != NULL) BN_CTX_free(ctx2); + if (ctx2 != NULL) BN_CTX_free(ctx2); + if (ctx3 != NULL) BN_CTX_free(ctx3); + if (ctx4 != NULL) BN_CTX_free(ctx4); if (mont != NULL) BN_MONT_CTX_free(mont); return(ok?ret:NULL); } - -int DSA_is_prime(w, callback,cb_arg) -BIGNUM *w; -void (*callback)(); -char *cb_arg; - { - int ok= -1,j,i,n; - BN_CTX *ctx=NULL,*ctx2=NULL; - BIGNUM *w_1,*b,*m,*z,*tmp,*mont_1; - int a; - BN_MONT_CTX *mont=NULL; - - if (!BN_is_bit_set(w,0)) return(0); - - if ((ctx=BN_CTX_new()) == NULL) goto err; - if ((ctx2=BN_CTX_new()) == NULL) goto err; - if ((mont=BN_MONT_CTX_new()) == NULL) goto err; - - m= &(ctx2->bn[2]); - b= &(ctx2->bn[3]); - z= &(ctx2->bn[4]); - w_1= &(ctx2->bn[5]); - tmp= &(ctx2->bn[6]); - mont_1= &(ctx2->bn[7]); - - /* step 1 */ - n=50; - - /* step 2 */ - if (!BN_sub(w_1,w,BN_value_one())) goto err; - for (a=1; !BN_is_bit_set(w_1,a); a++) - ; - if (!BN_rshift(m,w_1,a)) goto err; - - BN_MONT_CTX_set(mont,w,ctx); - BN_to_montgomery(mont_1,BN_value_one(),mont,ctx); - BN_to_montgomery(w_1,w_1,mont,ctx); - for (i=1; i < n; i++) - { - /* step 3 */ - BN_rand(b,BN_num_bits(w)-2/*-1*/,0,0); - /* BN_set_word(b,0x10001L); */ - - /* step 4 */ - j=0; - if (!BN_mod_exp_mont(z,b,m,w,ctx,mont)) goto err; - - if (!BN_to_montgomery(z,z,mont,ctx)) goto err; - - /* step 5 */ - for (;;) - { - if (((j == 0) && (BN_cmp(z,mont_1) == 0)) || - (BN_cmp(z,w_1) == 0)) - break; - - /* step 6 */ - if ((j > 0) && (BN_cmp(z,mont_1) == 0)) - { - ok=0; - goto err; - } - - j++; - if (j >= a) - { - ok=0; - goto err; - } - - if (!BN_mod_mul_montgomery(z,z,z,mont,ctx)) goto err; - if (callback != NULL) callback(1,j,cb_arg); - } - } - - ok=1; -err: - if (ok == -1) DSAerr(DSA_F_DSA_IS_PRIME,ERR_R_BN_LIB); - BN_CTX_free(ctx); - BN_CTX_free(ctx2); - - return(ok); - } - +#endif