Provisional, experimental support for DSA2 parameter generation algorithm.

Not properly integrated or tested yet.

4 files changed, 277 insertions, 2 deletions

diff --git a/crypto/dsa/dsa.h b/crypto/dsa/dsa.h
index d232f67fdb..06a7b1431d 100644
--- a/crypto/dsa/dsa.h
+++ b/crypto/dsa/dsa.h
@@ -296,6 +296,7 @@ void ERR_load_DSA_strings(void);
 #define DSA_F_DSAPARAMS_PRINT_FP			 101
 #define DSA_F_DSA_BUILTIN_KEYGEN			 124
 #define DSA_F_DSA_BUILTIN_PARAMGEN			 125
+#define DSA_F_DSA_BUILTIN_PARAMGEN2			 126
 #define DSA_F_DSA_DO_SIGN				 112
 #define DSA_F_DSA_DO_VERIFY				 113
 #define DSA_F_DSA_NEW_METHOD				 103
@@ -323,12 +324,14 @@ void ERR_load_DSA_strings(void);
 #define DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE		 100
 #define DSA_R_DECODE_ERROR				 104
 #define DSA_R_INVALID_DIGEST_TYPE			 106
+#define DSA_R_INVALID_PARAMETERS			 112
 #define DSA_R_KEY_SIZE_TOO_SMALL			 111
 #define DSA_R_MISSING_PARAMETERS			 101
 #define DSA_R_MODULUS_TOO_LARGE				 103
 #define DSA_R_NEED_NEW_SETUP_VALUES			 110
 #define DSA_R_NO_PARAMETERS_SET				 107
 #define DSA_R_PARAMETER_ENCODING_ERROR			 105
+#define DSA_R_Q_NOT_PRIME				 113
 
 #ifdef  __cplusplus
 }
diff --git a/crypto/dsa/dsa_err.c b/crypto/dsa/dsa_err.c
index 3241e57a8e..a46fade4c6 100644
--- a/crypto/dsa/dsa_err.c
+++ b/crypto/dsa/dsa_err.c
@@ -76,6 +76,7 @@ static ERR_STRING_DATA DSA_str_functs[]=
 {ERR_FUNC(DSA_F_DSAPARAMS_PRINT_FP),	"DSAparams_print_fp"},
 {ERR_FUNC(DSA_F_DSA_BUILTIN_KEYGEN),	"DSA_BUILTIN_KEYGEN"},
 {ERR_FUNC(DSA_F_DSA_BUILTIN_PARAMGEN),	"DSA_BUILTIN_PARAMGEN"},
+{ERR_FUNC(DSA_F_DSA_BUILTIN_PARAMGEN2),	"DSA_BUILTIN_PARAMGEN2"},
 {ERR_FUNC(DSA_F_DSA_DO_SIGN),	"DSA_do_sign"},
 {ERR_FUNC(DSA_F_DSA_DO_VERIFY),	"DSA_do_verify"},
 {ERR_FUNC(DSA_F_DSA_NEW_METHOD),	"DSA_new_method"},
@@ -106,12 +107,14 @@ static ERR_STRING_DATA DSA_str_reasons[]=
 {ERR_REASON(DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE),"data too large for key size"},
 {ERR_REASON(DSA_R_DECODE_ERROR)          ,"decode error"},
 {ERR_REASON(DSA_R_INVALID_DIGEST_TYPE)   ,"invalid digest type"},
+{ERR_REASON(DSA_R_INVALID_PARAMETERS)    ,"invalid parameters"},
 {ERR_REASON(DSA_R_KEY_SIZE_TOO_SMALL)    ,"key size too small"},
 {ERR_REASON(DSA_R_MISSING_PARAMETERS)    ,"missing parameters"},
 {ERR_REASON(DSA_R_MODULUS_TOO_LARGE)     ,"modulus too large"},
 {ERR_REASON(DSA_R_NEED_NEW_SETUP_VALUES) ,"need new setup values"},
 {ERR_REASON(DSA_R_NO_PARAMETERS_SET)     ,"no parameters set"},
 {ERR_REASON(DSA_R_PARAMETER_ENCODING_ERROR),"parameter encoding error"},
+{ERR_REASON(DSA_R_Q_NOT_PRIME)           ,"q not prime"},
 {0,NULL}
 	};
 
diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c
index d5a41c249a..7f8ee8f727 100644
--- a/crypto/dsa/dsa_gen.c
+++ b/crypto/dsa/dsa_gen.c
@@ -136,8 +136,7 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
 #ifdef OPENSSL_FIPS
 	if(FIPS_selftest_failed())
 	    {
-	    FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN,
-		    FIPS_R_FIPS_SELFTEST_FAILED);
+	    FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN, FIPS_R_FIPS_SELFTEST_FAILED);
 	    goto err;
 	    }
 
@@ -369,4 +368,269 @@ err:
 	if (mont != NULL) BN_MONT_CTX_free(mont);
 	return ok;
 	}
+
+/* Permissible parameter values for (L,N): see FIPS186-3 4.2 */
+
+static int dsa2_check_params(size_t L, size_t N)
+	{
+	if (L == 1024 && N == 160)
+		return 1;
+	if (L == 2048 && N == 224)
+		return 1;
+	if (L == 2048 && N == 256)
+		return 1;
+	if (L == 3072 && N == 256)
+		return 1;
+	return 0;
+	}
+
+/* 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,
+	unsigned char *seed_out,
+	int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
+	{
+	int ok=-1;
+	unsigned char *seed = 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;
+	unsigned int h=2;
+
+#ifdef OPENSSL_FIPS
+	if(FIPS_selftest_failed())
+	    {
+	    FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN2,
+		    FIPS_R_FIPS_SELFTEST_FAILED);
+	    goto err;
+	    }
+#endif
+	if (!dsa2_check_params(L, N))
+		{
+		DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS);
+		ok = 0;
+		goto err;
+		}
+
+	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 (seed_len == 0)
+		seed_len = mdsize;
+
+	seed = OPENSSL_malloc(seed_len);
+
+	if (!seed)
+		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);
+	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(),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)
+				RAND_pseudo_bytes(seed, qsize);
+			/* 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 */
+			}
+
+		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 >= 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=-1;
+			goto err;
+			}
+		if (counter_ret != NULL) *counter_ret=counter;
+		if (h_ret != NULL) *h_ret=h;
+		if (seed_out)
+			memcpy(seed_out, seed, seed_len);
+		}
+	if (seed)
+		OPENSSL_free(seed);
+	if(ctx)
+		{
+		BN_CTX_end(ctx);
+		BN_CTX_free(ctx);
+		}
+	if (mont != NULL) BN_MONT_CTX_free(mont);
+	return ok;
+	}
 #endif
diff --git a/crypto/dsa/dsa_locl.h b/crypto/dsa/dsa_locl.h
index 21e2e45242..4e07c7cbab 100644
--- a/crypto/dsa/dsa_locl.h
+++ b/crypto/dsa/dsa_locl.h
@@ -58,3 +58,8 @@ 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 dsa_builtin_paramgen2(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);