X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fdsa%2Fdsa_gen.c;h=aae860e1947a0cbdb48a0030ff41be94230b2c21;hp=a7d478324e2d8510cb05b0a52a4f0d98d625d462;hb=e4e5bc39f9481b9c0842ad5b6d0ac338a9742281;hpb=c8bbd98a2b0c2a5164c42f951cd2866512839b5a

diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c
index a7d478324e..aae860e194 100644
--- a/crypto/dsa/dsa_gen.c
+++ b/crypto/dsa/dsa_gen.c
@@ -73,12 +73,19 @@
 
 #ifndef OPENSSL_NO_SHA
 
+#define OPENSSL_FIPSAPI
+
 #include <stdio.h>
 #include "cryptlib.h"
 #include <openssl/evp.h>
 #include <openssl/bn.h>
 #include <openssl/rand.h>
 #include <openssl/sha.h>
+#ifdef OPENSSL_FIPS
+#include <openssl/fips.h>
+#include <openssl/fips_rand.h>
+#endif
+
 #include "dsa_locl.h"
 
 int DSA_generate_parameters_ex(DSA *ret, int bits,
@@ -105,12 +112,13 @@ int DSA_generate_parameters_ex(DSA *ret, int bits,
 			}
 
 		return dsa_builtin_paramgen(ret, bits, qbits, evpmd,
-				seed_in, seed_len, counter_ret, h_ret, cb);
+			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;
@@ -126,6 +134,21 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
 	BN_CTX *ctx=NULL;
 	unsigned int h=2;
 
+#ifdef OPENSSL_FIPS
+	if(FIPS_selftest_failed())
+	    {
+	    FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN, FIPS_R_FIPS_SELFTEST_FAILED);
+	    goto err;
+	    }
+
+	if (FIPS_module_mode() && !(ret->flags & DSA_FLAG_NON_FIPS_ALLOW) 
+			&& (bits < OPENSSL_DSA_FIPS_MIN_MODULUS_BITS))
+		{
+		DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN, DSA_R_KEY_SIZE_TOO_SMALL);
+		goto err;
+		}
+#endif
+
 	if (qsize != SHA_DIGEST_LENGTH && qsize != SHA224_DIGEST_LENGTH &&
 	    qsize != SHA256_DIGEST_LENGTH)
 		/* invalid q size */
@@ -182,7 +205,8 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
 
 			if (!seed_len)
 				{
-				RAND_pseudo_bytes(seed, qsize);
+				if (RAND_pseudo_bytes(seed, qsize) < 0)
+					goto err;
 				seed_is_random = 1;
 				}
 			else
@@ -336,6 +360,8 @@ 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)
 		{
@@ -345,4 +371,436 @@ err:
 	if (mont != NULL) BN_MONT_CTX_free(mont);
 	return ok;
 	}
+
+#ifdef OPENSSL_FIPS
+
+/* Security strength of parameter values for (L,N): see FIPS186-3 4.2
+ * and SP800-131A
+ */
+
+
+static int fips_ffc_strength(size_t L, size_t N)
+	{
+	if (L >= 15360 && N >= 512)
+		return 256;
+	if (L >= 7680 && N >= 384)
+		return 192;
+	if (L >= 3072 && N >= 256)
+		return 128;
+	if (L >= 2048 && N >= 224)
+		return 112;
+	if (L >= 1024 && N >= 160)
+		return  80;
+	return 0;
+	}
+
+/* Valid DSA2 parameters from FIPS 186-3 */
+
+static int dsa2_valid_parameters(size_t L, size_t N)
+	{
+	if (L == 1024 && N == 160)
+		return 80;
+	if (L == 2048 && N == 224)
+		return 112;
+	if (L == 2048 && N == 256)
+		return 112;
+	if (L == 3072 && N == 256)
+		return 128;
+	return 0;
+	}
+
+int fips_check_dsa_prng(DSA *dsa, size_t L, size_t N)
+	{
+	int strength;
+	if (!FIPS_module_mode())
+		return 1;
+
+	if (dsa->flags & (DSA_FLAG_NON_FIPS_ALLOW|DSA_FLAG_FIPS_CHECKED))
+		return 1;
+
+	if (!L || !N)
+		{
+		L = BN_num_bits(dsa->p);
+		N = BN_num_bits(dsa->q);
+		}
+	if (!dsa2_valid_parameters(L, N))
+		{
+		FIPSerr(FIPS_F_FIPS_CHECK_DSA_PRNG, FIPS_R_INVALID_PARAMETERS);
+		return 0;
+		}
+
+	strength = fips_ffc_strength(L, N);
+
+	if (!strength)
+		{
+	    	FIPSerr(FIPS_F_FIPS_CHECK_DSA_PRNG,FIPS_R_KEY_TOO_SHORT);
+		return 0;
+		}
+
+	if (FIPS_rand_strength() >= strength)
+		return 1;
+
+	FIPSerr(FIPS_F_FIPS_CHECK_DSA_PRNG,FIPS_R_PRNG_STRENGTH_TOO_LOW);
+	return 0;
+
+	}
+#endif /* OPENSSL_FIPS */
+
+/* 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;
+
+	EVP_MD_CTX_init(&mctx);
+
+#ifdef OPENSSL_FIPS
+	if(FIPS_selftest_failed())
+	    {
+	    FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN2,
+		    FIPS_R_FIPS_SELFTEST_FAILED);
+	    goto err;
+	    }
+
+	if (!fips_check_dsa_prng(ret, L, N))
+		goto err;
+#endif
+
+	if (evpmd == NULL)
+		{
+		if (N == 160)
+			evpmd = EVP_sha1();
+		else if (N == 224)
+			evpmd = EVP_sha224();
+		else
+			evpmd = EVP_sha256();
+		}
+
+	mdsize = M_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