Commit 3fa23ff0 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Add FIPS 186-2 DSA parameter generation algorithm. 

Backport support for FIPS 186-2 DSA parameter generation from
HEAD. Redirect to FIPS in FIPS mode and workaround prototype error.
parent c275fb09

crypto/dsa/dsa.h

+3 −0
Original line number Diff line number Diff line
@@ -285,6 +285,7 @@ void ERR_load_DSA_strings(void); 
#define DSA_F_DO_DSA_PRINT				 104

#define DSA_F_DSAPARAMS_PRINT				 100

#define DSA_F_DSAPARAMS_PRINT_FP			 101

#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_GENERATE_KEY				 124
@@ -314,12 +315,14 @@ 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_MISSING_PARAMETERS			 101

#define DSA_R_MODULUS_TOO_LARGE				 103

#define DSA_R_NEED_NEW_SETUP_VALUES			 110

#define DSA_R_NON_FIPS_DSA_METHOD			 111

#define DSA_R_NO_PARAMETERS_SET				 107

#define DSA_R_PARAMETER_ENCODING_ERROR			 105

#define DSA_R_Q_NOT_PRIME				 113



#ifdef  __cplusplus

}

crypto/dsa/dsa_err.c

+4 −1
Original line number Diff line number Diff line 
/* crypto/dsa/dsa_err.c */

/* ====================================================================

 * Copyright (c) 1999-2011 The OpenSSL Project.  All rights reserved.

 * Copyright (c) 1999-2013 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions
@@ -74,6 +74,7 @@ static ERR_STRING_DATA DSA_str_functs[]= 
{ERR_FUNC(DSA_F_DO_DSA_PRINT),	"DO_DSA_PRINT"},

{ERR_FUNC(DSA_F_DSAPARAMS_PRINT),	"DSAparams_print"},

{ERR_FUNC(DSA_F_DSAPARAMS_PRINT_FP),	"DSAparams_print_fp"},

{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_GENERATE_KEY),	"DSA_generate_key"},
@@ -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_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_NON_FIPS_DSA_METHOD)   ,"non fips dsa method"},

{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}

	};

crypto/dsa/dsa_gen.c

+364 −0
Original line number Diff line number Diff line
@@ -82,6 +82,8 @@ 
#include "dsa_locl.h"



#ifdef OPENSSL_FIPS

/* Workaround bug in prototype */

#define fips_dsa_builtin_paramgen2 fips_dsa_paramgen_bad

#include <openssl/fips.h>

#endif
@@ -368,4 +370,366 @@ err: 
	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

crypto/dsa/dsa_locl.h

+7 −0
Original line number Diff line number Diff line
@@ -58,3 +58,10 @@ 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 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 dsa_paramgen_check_g(DSA *dsa);