Initial support for DSA_METHOD...

CHANGES

@@ -4,6 +4,14 @@
 
  Changes between 0.9.4 and 0.9.5  [xx XXX 1999]
 
+  *) Initial support for DSA_METHOD. This is based on the RSA_METHOD and
+     provides hooks that allow the default DSA functions or functions on a
+     "per key" basis to be replaced. This allows hardware acceleration and
+     hardware key storage to be handled without major modification to the
+     library. Also added low level modexp hooks and CRYPTO_EX structure and 
+     associated functions.
+     [Steve Henson]
+
   *) Add a new flag to memory BIOs, BIO_FLAG_MEM_RDONLY. This marks the BIO
      as "read only": it can't be written to and the buffer it points to will
      not be freed. Reading from a read only BIO is much more efficient than

crypto/dsa/Makefile.ssl

@@ -22,8 +22,10 @@ TEST=dsatest.c
 APPS=
 
 LIB=$(TOP)/libcrypto.a
-LIBSRC= dsa_gen.c dsa_key.c dsa_lib.c dsa_asn1.c dsa_vrf.c dsa_sign.c dsa_err.c
-LIBOBJ= dsa_gen.o dsa_key.o dsa_lib.o dsa_asn1.o dsa_vrf.o dsa_sign.o dsa_err.o
+LIBSRC= dsa_gen.c dsa_key.c dsa_lib.c dsa_asn1.c dsa_vrf.c dsa_sign.c \
+	dsa_err.c dsa_ossl.c
+LIBOBJ= dsa_gen.o dsa_key.o dsa_lib.o dsa_asn1.o dsa_vrf.o dsa_sign.o \
+	dsa_err.o dsa_ossl.o
 
 SRC= $(LIBSRC)
 

crypto/dsa/dsa.h

@@ -74,13 +74,41 @@ extern "C" {
 #endif
 
 #include <openssl/bn.h>
+#include <openssl/crypto.h>
 #ifndef NO_DH
 # include <openssl/dh.h>
 #endif
 
 #define DSA_FLAG_CACHE_MONT_P	0x01
 
-typedef struct dsa_st
+typedef struct dsa_st DSA;
+
+typedef struct DSA_SIG_st
+	{
+	BIGNUM *r;
+	BIGNUM *s;
+	} DSA_SIG;
+
+typedef struct dsa_method {
+	const char *name;
+	DSA_SIG * (*dsa_do_sign)(const unsigned char *dgst, int dlen, DSA *dsa);
+	int (*dsa_sign_setup)(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
+								BIGNUM **rp);
+	int (*dsa_do_verify)(const unsigned char *dgst, int dgst_len,
+							DSA_SIG *sig, DSA *dsa);
+	int (*dsa_mod_exp)(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
+			BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
+			BN_MONT_CTX *in_mont);
+	int (*bn_mod_exp)(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
+				const BIGNUM *m, BN_CTX *ctx,
+				BN_MONT_CTX *m_ctx); /* Can be null */
+	int (*init)(DSA *dsa);
+	int (*finish)(DSA *dsa);
+	int flags;
+	char *app_data;
+} DSA_METHOD;
+
+struct dsa_st
 	{
 	/* This first variable is used to pick up errors where
 	 * a DSA is passed instead of of a EVP_PKEY */
@@ -100,15 +128,10 @@ typedef struct dsa_st
 	int flags;
 	/* Normally used to cache montgomery values */
 	char *method_mont_p;
-
 	int references;
-	} DSA;
-
-typedef struct DSA_SIG_st
-	{
-	BIGNUM *r;
-	BIGNUM *s;
-	} DSA_SIG;
+	CRYPTO_EX_DATA ex_data;
+	DSA_METHOD *meth;
+	};
 
 #define DSAparams_dup(x) (DSA *)ASN1_dup((int (*)())i2d_DSAparams, \
 		(char *(*)())d2i_DSAparams,(char *)(x))
@@ -131,7 +154,10 @@ DSA_SIG * DSA_do_sign(const unsigned char *dgst,int dlen,DSA *dsa);
 int	DSA_do_verify(const unsigned char *dgst,int dgst_len,
 		      DSA_SIG *sig,DSA *dsa);
 
+DSA_METHOD *DSA_OpenSSL(void);
+
 DSA *	DSA_new(void);
+DSA *	DSA_new_method(DSA_METHOD *meth);
 int	DSA_size(DSA *);
 	/* next 4 return -1 on error */
 int	DSA_sign_setup( DSA *dsa,BN_CTX *ctx_in,BIGNUM **kinvp,BIGNUM **rp);
@@ -140,6 +166,10 @@ int	DSA_sign(int type,const unsigned char *dgst,int dlen,
 int	DSA_verify(int type,const unsigned char *dgst,int dgst_len,
 		unsigned char *sigbuf, int siglen, DSA *dsa);
 void	DSA_free (DSA *r);
+int DSA_get_ex_new_index(long argl, char *argp, int (*new_func)(),
+	     int (*dup_func)(), void (*free_func)());
+int DSA_set_ex_data(DSA *d, int idx, char *arg);
+char *DSA_get_ex_data(DSA *d, int idx);
 
 void	ERR_load_DSA_strings(void );
 

crypto/dsa/dsa_lib.c

@@ -66,11 +66,45 @@
 
 const char *DSA_version="DSA" OPENSSL_VERSION_PTEXT;
 
+static DSA_METHOD *default_DSA_method;
+static int dsa_meth_num = 0;
+static STACK *dsa_meth = NULL;
+
+void DSA_set_default_method(DSA_METHOD *meth)
+{
+	default_DSA_method = meth;
+}
+
+DSA_METHOD *DSA_get_default_method(void)
+{
+	if(!default_DSA_method) default_DSA_method = DSA_OpenSSL();
+	return default_DSA_method;
+}
+
 DSA *DSA_new(void)
+{
+	return DSA_new_method(NULL);
+}
+
+DSA_METHOD *DSA_set_method(DSA *dsa, DSA_METHOD *meth)
+{
+        DSA_METHOD *mtmp;
+        mtmp = dsa->meth;
+        if (mtmp->finish) mtmp->finish(dsa);
+        dsa->meth = meth;
+        if (meth->init) meth->init(dsa);
+        return mtmp;
+}
+
+
+DSA *DSA_new_method(DSA_METHOD *meth)
 	{
 	DSA *ret;
 
 	ret=(DSA *)Malloc(sizeof(DSA));
+	if(!default_DSA_method) default_DSA_method = DSA_OpenSSL();
+	if(meth) ret->meth = meth;
+	else ret->meth = default_DSA_method;
 	if (ret == NULL)
 		{
 		DSAerr(DSA_F_DSA_NEW,ERR_R_MALLOC_FAILURE);
@@ -82,7 +116,6 @@ DSA *DSA_new(void)
 	ret->p=NULL;
 	ret->q=NULL;
 	ret->g=NULL;
-	ret->flags=DSA_FLAG_CACHE_MONT_P;
 
 	ret->pub_key=NULL;
 	ret->priv_key=NULL;
@@ -92,6 +125,16 @@ DSA *DSA_new(void)
 	ret->method_mont_p=NULL;
 
 	ret->references=1;
+	/* ret->flags=DSA_FLAG_CACHE_MONT_P; */
+	ret->flags=ret->meth->flags;
+	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
+		{
+		Free(ret);
+		ret=NULL;
+		}
+	else
+		CRYPTO_new_ex_data(dsa_meth,(char *)ret,&ret->ex_data);
+	
 	return(ret);
 	}
 
@@ -114,6 +157,10 @@ void DSA_free(DSA *r)
 		}
 #endif
 
+	CRYPTO_free_ex_data(dsa_meth, (char *)r, &r->ex_data);
+
+	if(r->meth->finish) r->meth->finish(r);
+
 	if (r->p != NULL) BN_clear_free(r->p);
 	if (r->q != NULL) BN_clear_free(r->q);
 	if (r->g != NULL) BN_clear_free(r->g);
@@ -145,6 +192,24 @@ int DSA_size(DSA *r)
 	return(ret);
 	}
 
+int DSA_get_ex_new_index(long argl, char *argp, int (*new_func)(),
+	     int (*dup_func)(), void (*free_func)())
+        {
+	dsa_meth_num++;
+	return(CRYPTO_get_ex_new_index(dsa_meth_num-1,
+		&dsa_meth,argl,argp,new_func,dup_func,free_func));
+        }
+
+int DSA_set_ex_data(DSA *d, int idx, char *arg)
+	{
+	return(CRYPTO_set_ex_data(&d->ex_data,idx,arg));
+	}
+
+char *DSA_get_ex_data(DSA *d, int idx)
+	{
+	return(CRYPTO_get_ex_data(&d->ex_data,idx));
+	}
+
 #ifndef NO_DH
 DH *DSA_dup_DH(DSA *r)
 	{

crypto/dsa/dsa_ossl.c

+/* crypto/dsa/dsa_ossl.c */
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * 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:
+ * 1. Redistributions of source code must retain the copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *    "This product includes cryptographic software written by
+ *     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 
+ *    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
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * 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
+ * [including the GNU Public Licence.]
+ */
+
+/* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
+
+#include <stdio.h>
+#include "cryptlib.h"
+#include <openssl/bn.h>
+#include <openssl/dsa.h>
+#include <openssl/rand.h>
+#include <openssl/asn1.h>
+
+static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
+int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
+static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
+		  DSA *dsa);
+static int dsa_init(DSA *dsa);
+static int dsa_finish(DSA *dsa);
+static int dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
+		BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
+		BN_MONT_CTX *in_mont);
+static int dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
+				const BIGNUM *m, BN_CTX *ctx,
+				BN_MONT_CTX *m_ctx);
+
+static DSA_METHOD openssl_dsa_meth = {
+"OpenSSL DSA method",
+dsa_do_sign,
+dsa_sign_setup,
+dsa_do_verify,
+dsa_mod_exp,
+dsa_bn_mod_exp,
+dsa_init,
+dsa_finish,
+0,
+NULL
+};
+
+DSA_METHOD *DSA_OpenSSL(void)
+{
+	return &openssl_dsa_meth;
+}
+
+static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
+	{
+	BIGNUM *kinv=NULL,*r=NULL,*s=NULL;
+	BIGNUM m;
+	BIGNUM xr;
+	BN_CTX *ctx=NULL;
+	int i,reason=ERR_R_BN_LIB;
+	DSA_SIG *ret=NULL;
+
+	BN_init(&m);
+	BN_init(&xr);
+	s=BN_new();
+	if (s == NULL) goto err;
+
+	i=BN_num_bytes(dsa->q); /* should be 20 */
+	if ((dlen > i) || (dlen > 50))
+		{
+		reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
+		goto err;
+		}
+
+	ctx=BN_CTX_new();
+	if (ctx == NULL) goto err;
+
+	if ((dsa->kinv == NULL) || (dsa->r == NULL))
+		{
+		if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err;
+		}
+	else
+		{
+		kinv=dsa->kinv;
+		dsa->kinv=NULL;
+		r=dsa->r;
+		dsa->r=NULL;
+		}
+
+	if (BN_bin2bn(dgst,dlen,&m) == NULL) goto err;
+
+	/* Compute  s = inv(k) (m + xr) mod q */
+	if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */
+	if (!BN_add(s, &xr, &m)) goto err;		/* s = m + xr */
+	if (BN_cmp(s,dsa->q) > 0)
+		BN_sub(s,s,dsa->q);
+	if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err;
+
+	ret=DSA_SIG_new();
+	if (ret == NULL) goto err;
+	ret->r = r;
+	ret->s = s;
+	
+err:
+	if (!ret)
+		{
+		DSAerr(DSA_F_DSA_DO_SIGN,reason);
+		BN_free(r);
+		BN_free(s);
+		}
+	if (ctx != NULL) BN_CTX_free(ctx);
+	BN_clear_free(&m);
+	BN_clear_free(&xr);
+	if (kinv != NULL) /* dsa->kinv is NULL now if we used it */
+	    BN_clear_free(kinv);
+	return(ret);
+	}
+
+int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
+	{
+	BN_CTX *ctx;
+	BIGNUM k,*kinv=NULL,*r=NULL;
+	int ret=0;
+
+	if (ctx_in == NULL)
+		{
+		if ((ctx=BN_CTX_new()) == NULL) goto err;
+		}
+	else
+		ctx=ctx_in;
+
+	BN_init(&k);
+	if ((r=BN_new()) == NULL) goto err;
+	kinv=NULL;
+
+	/* Get random k */
+	for (;;)
+		{
+		if (!BN_rand(&k, BN_num_bits(dsa->q), 1, 0)) goto err;
+		if (BN_cmp(&k,dsa->q) >= 0)
+			BN_sub(&k,&k,dsa->q);
+		if (!BN_is_zero(&k)) break;
+		}
+
+	if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
+		{
+		if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
+			if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
+				dsa->p,ctx)) goto err;
+		}
+
+	/* Compute r = (g^k mod p) mod q */
+	if (!dsa->meth->bn_mod_exp(dsa, r,dsa->g,&k,dsa->p,ctx,
+		(BN_MONT_CTX *)dsa->method_mont_p)) goto err;
+	if (!BN_mod(r,r,dsa->q,ctx)) goto err;
+
+	/* Compute  part of 's = inv(k) (m + xr) mod q' */
+	if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err;
+
+	if (*kinvp != NULL) BN_clear_free(*kinvp);
+	*kinvp=kinv;
+	kinv=NULL;
+	if (*rp != NULL) BN_clear_free(*rp);
+	*rp=r;
+	ret=1;
+err:
+	if (!ret)
+		{
+		DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB);
+		if (kinv != NULL) BN_clear_free(kinv);
+		if (r != NULL) BN_clear_free(r);
+		}
+	if (ctx_in == NULL) BN_CTX_free(ctx);
+	if (kinv != NULL) BN_clear_free(kinv);
+	BN_clear_free(&k);
+	return(ret);
+	}
+
+static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
+		  DSA *dsa)
+	{
+	BN_CTX *ctx;
+	BIGNUM u1,u2,t1;
+	BN_MONT_CTX *mont=NULL;
+	int ret = -1;
+
+	if ((ctx=BN_CTX_new()) == NULL) goto err;
+	BN_init(&u1);
+	BN_init(&u2);
+	BN_init(&t1);
+
+	/* Calculate W = inv(S) mod Q
+	 * save W in u2 */
+	if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err;
+
+	/* save M in u1 */
+	if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err;
+
+	/* u1 = M * w mod q */
+	if (!BN_mod_mul(&u1,&u1,&u2,dsa->q,ctx)) goto err;
+
+	/* u2 = r * w mod q */
+	if (!BN_mod_mul(&u2,sig->r,&u2,dsa->q,ctx)) goto err;
+
+	if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
+		{
+		if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
+			if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
+				dsa->p,ctx)) goto err;
+		}
+	mont=(BN_MONT_CTX *)dsa->method_mont_p;
+
+#if 0
+	{
+	BIGNUM t2;
+
+	BN_init(&t2);
+	/* v = ( g^u1 * y^u2 mod p ) mod q */
+	/* let t1 = g ^ u1 mod p */
+	if (!BN_mod_exp_mont(&t1,dsa->g,&u1,dsa->p,ctx,mont)) goto err;
+	/* let t2 = y ^ u2 mod p */
+	if (!BN_mod_exp_mont(&t2,dsa->pub_key,&u2,dsa->p,ctx,mont)) goto err;
+	/* let u1 = t1 * t2 mod p */
+	if (!BN_mod_mul(&u1,&t1,&t2,dsa->p,ctx)) goto err_bn;
+	BN_free(&t2);
+	}
+	/* let u1 = u1 mod q */
+	if (!BN_mod(&u1,&u1,dsa->q,ctx)) goto err;
+#else
+	{
+	if (!dsa->meth->dsa_mod_exp(dsa, &t1,dsa->g,&u1,dsa->pub_key,&u2,
+						dsa->p,ctx,mont)) goto err;
+	/* BN_copy(&u1,&t1); */
+	/* let u1 = u1 mod q */
+	if (!BN_mod(&u1,&t1,dsa->q,ctx)) goto err;
+	}
+#endif
+	/* V is now in u1.  If the signature is correct, it will be
+	 * equal to R. */
+	ret=(BN_ucmp(&u1, sig->r) == 0);
+
+	err:
+	if (ret != 1) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB);
+	if (ctx != NULL) BN_CTX_free(ctx);
+	BN_free(&u1);
+	BN_free(&u2);
+	BN_free(&t1);
+	return(ret);
+	}
+
+static int dsa_init(DSA *dsa)
+{
+	dsa->flags=DSA_FLAG_CACHE_MONT_P;
+	return(1);
+}
+
+static int dsa_finish(DSA *dsa)
+{
+	return(1);
+}
+
+static int dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
+		BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
+		BN_MONT_CTX *in_mont)
+{
+	return BN_mod_exp2_mont(rr, a1, p1, a2, p2, m, ctx, in_mont);
+}
+	
+static int dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
+				const BIGNUM *m, BN_CTX *ctx,
+				BN_MONT_CTX *m_ctx)
+{
+	return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
+}

crypto/dsa/dsa_sign.c

@@ -67,73 +67,9 @@
 
 DSA_SIG * DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
 	{
-	BIGNUM *kinv=NULL,*r=NULL,*s=NULL;
-	BIGNUM m;
-	BIGNUM xr;
-	BN_CTX *ctx=NULL;
-	int i,reason=ERR_R_BN_LIB;
-	DSA_SIG *ret=NULL;
-
-	BN_init(&m);
-	BN_init(&xr);
-	s=BN_new();
-	if (s == NULL) goto err;
-
-	i=BN_num_bytes(dsa->q); /* should be 20 */
-	if ((dlen > i) || (dlen > 50))
-		{
-		reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
-		goto err;
-		}
-
-	ctx=BN_CTX_new();
-	if (ctx == NULL) goto err;
-
-	if ((dsa->kinv == NULL) || (dsa->r == NULL))
-		{
-		if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err;
-		}
-	else
-		{
-		kinv=dsa->kinv;
-		dsa->kinv=NULL;
-		r=dsa->r;
-		dsa->r=NULL;
-		}
-
-	if (BN_bin2bn(dgst,dlen,&m) == NULL) goto err;
-
-	/* Compute  s = inv(k) (m + xr) mod q */
-	if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */
-	if (!BN_add(s, &xr, &m)) goto err;		/* s = m + xr */
-	if (BN_cmp(s,dsa->q) > 0)
-		BN_sub(s,s,dsa->q);
-	if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err;
-
-	ret=DSA_SIG_new();
-	if (ret == NULL) goto err;
-	ret->r = r;
-	ret->s = s;
-	
-err:
-	if (!ret)
-		{
-		DSAerr(DSA_F_DSA_DO_SIGN,reason);
-		BN_free(r);
-		BN_free(s);
-		}
-	if (ctx != NULL) BN_CTX_free(ctx);
-	BN_clear_free(&m);
-	BN_clear_free(&xr);
-	if (kinv != NULL) /* dsa->kinv is NULL now if we used it */
-	    BN_clear_free(kinv);
-	return(ret);
+	return dsa->meth->dsa_do_sign(dgst, dlen, dsa);
 	}
 
-/* data has already been hashed (probably with SHA or SHA-1). */
-
-/* unsigned char *sig:  out    */
-/* unsigned int *siglen:  out    */
 int DSA_sign(int type, const unsigned char *dgst, int dlen, unsigned char *sig,
 	     unsigned int *siglen, DSA *dsa)
 	{
@@ -151,61 +87,6 @@ int DSA_sign(int type, const unsigned char *dgst, int dlen, unsigned char *sig,
 
 int DSA_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
 	{
-	BN_CTX *ctx;
-	BIGNUM k,*kinv=NULL,*r=NULL;
-	int ret=0;
-
-	if (ctx_in == NULL)
-		{
-		if ((ctx=BN_CTX_new()) == NULL) goto err;
-		}
-	else
-		ctx=ctx_in;
-
-	BN_init(&k);
-	if ((r=BN_new()) == NULL) goto err;
-	kinv=NULL;
-
-	/* Get random k */
-	for (;;)
-		{
-		if (!BN_rand(&k, BN_num_bits(dsa->q), 1, 0)) goto err;
-		if (BN_cmp(&k,dsa->q) >= 0)
-			BN_sub(&k,&k,dsa->q);
-		if (!BN_is_zero(&k)) break;
-		}
-
-	if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
-		{
-		if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
-			if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
-				dsa->p,ctx)) goto err;
-		}
-
-	/* Compute r = (g^k mod p) mod q */
-	if (!BN_mod_exp_mont(r,dsa->g,&k,dsa->p,ctx,
-		(BN_MONT_CTX *)dsa->method_mont_p)) goto err;
-	if (!BN_mod(r,r,dsa->q,ctx)) goto err;
-
-	/* Compute  part of 's = inv(k) (m + xr) mod q' */
-	if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err;
-
-	if (*kinvp != NULL) BN_clear_free(*kinvp);
-	*kinvp=kinv;
-	kinv=NULL;
-	if (*rp != NULL) BN_clear_free(*rp);
-	*rp=r;
-	ret=1;
-err:
-	if (!ret)
-		{
-		DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB);
-		if (kinv != NULL) BN_clear_free(kinv);
-		if (r != NULL) BN_clear_free(r);
-		}
-	if (ctx_in == NULL) BN_CTX_free(ctx);
-	if (kinv != NULL) BN_clear_free(kinv);
-	BN_clear_free(&k);
-	return(ret);
+	return dsa->meth->dsa_sign_setup(dsa, ctx_in, kinvp, rp);
 	}
 

crypto/dsa/dsa_vrf.c

@@ -69,73 +69,7 @@
 int DSA_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
 		  DSA *dsa)
 	{
-	BN_CTX *ctx;
-	BIGNUM u1,u2,t1;
-	BN_MONT_CTX *mont=NULL;
-	int ret = -1;
-
-	if ((ctx=BN_CTX_new()) == NULL) goto err;
-	BN_init(&u1);
-	BN_init(&u2);
-	BN_init(&t1);
-
-	/* Calculate W = inv(S) mod Q
-	 * save W in u2 */
-	if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err;
-
-	/* save M in u1 */
-	if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err;
-
-	/* u1 = M * w mod q */
-	if (!BN_mod_mul(&u1,&u1,&u2,dsa->q,ctx)) goto err;
-
-	/* u2 = r * w mod q */
-	if (!BN_mod_mul(&u2,sig->r,&u2,dsa->q,ctx)) goto err;
-
-	if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
-		{
-		if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
-			if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
-				dsa->p,ctx)) goto err;
-		}
-	mont=(BN_MONT_CTX *)dsa->method_mont_p;
-
-#if 0
-	{
-	BIGNUM t2;
-
-	BN_init(&t2);
-	/* v = ( g^u1 * y^u2 mod p ) mod q */
-	/* let t1 = g ^ u1 mod p */
-	if (!BN_mod_exp_mont(&t1,dsa->g,&u1,dsa->p,ctx,mont)) goto err;
-	/* let t2 = y ^ u2 mod p */
-	if (!BN_mod_exp_mont(&t2,dsa->pub_key,&u2,dsa->p,ctx,mont)) goto err;
-	/* let u1 = t1 * t2 mod p */
-	if (!BN_mod_mul(&u1,&t1,&t2,dsa->p,ctx)) goto err_bn;
-	BN_free(&t2);
-	}
-	/* let u1 = u1 mod q */
-	if (!BN_mod(&u1,&u1,dsa->q,ctx)) goto err;
-#else
-	{
-	if (!BN_mod_exp2_mont(&t1,dsa->g,&u1,dsa->pub_key,&u2,dsa->p,ctx,mont))
-		goto err;
-	/* BN_copy(&u1,&t1); */
-	/* let u1 = u1 mod q */
-	if (!BN_mod(&u1,&t1,dsa->q,ctx)) goto err;
-	}
-#endif
-	/* V is now in u1.  If the signature is correct, it will be
-	 * equal to R. */
-	ret=(BN_ucmp(&u1, sig->r) == 0);
-
-	err:
-	if (ret != 1) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB);
-	if (ctx != NULL) BN_CTX_free(ctx);
-	BN_free(&u1);
-	BN_free(&u2);
-	BN_free(&t1);
-	return(ret);
+	return dsa->meth->dsa_do_verify(dgst, dgst_len, sig, dsa);
 	}
 
 /* data has already been hashed (probably with SHA or SHA-1). */