X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_mont.c;h=3a087fdce9ee8a5ffd16758146adf9ebedbc54b9;hp=d40a153f24d366d005bd430870b4e69ef556e440;hb=9b4eab501a52c8bdc19a8a002e1f9d4d7ad6f4c4;hpb=2d978cbd30f60f9e9ddaf743d818ef66ec217f47

diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c
index d40a153f24..3a087fdce9 100644
--- a/crypto/bn/bn_mont.c
+++ b/crypto/bn/bn_mont.c
@@ -69,74 +69,76 @@
 
 #define MONT_WORD /* use the faster word-based algorithm */
 
-int BN_mod_mul_montgomery(BIGNUM *r, BIGNUM *a, BIGNUM *b,
+#ifdef MONT_WORD
+static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont);
+#endif
+
+int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
 			  BN_MONT_CTX *mont, BN_CTX *ctx)
 	{
-	BIGNUM *tmp,*tmp2;
+	BIGNUM *tmp;
 	int ret=0;
+#if defined(OPENSSL_BN_ASM_MONT) && defined(MONT_WORD)
+	int num = mont->N.top;
+
+	if (num>1 && a->top==num && b->top==num)
+		{
+		if (bn_wexpand(r,num) == NULL) return(0);
+		if (bn_mul_mont(r->d,a->d,b->d,mont->N.d,mont->n0,num))
+			{
+			r->neg = a->neg^b->neg;
+			r->top = num;
+			bn_correct_top(r);
+			return(1);
+			}
+		}
+#endif
 
 	BN_CTX_start(ctx);
 	tmp = BN_CTX_get(ctx);
-	tmp2 = BN_CTX_get(ctx);
-	if (tmp == NULL || tmp2 == NULL) goto err;
+	if (tmp == NULL) goto err;
 
 	bn_check_top(tmp);
-	bn_check_top(tmp2);
-
 	if (a == b)
 		{
-#if 1 
-		bn_wexpand(tmp,a->top*2);
-		bn_wexpand(tmp2,a->top*4);
-		bn_sqr_recursive(tmp->d,a->d,a->top,tmp2->d);
-		tmp->top=a->top*2;
-		if (tmp->top > 0 && tmp->d[tmp->top-1] == 0)
-			tmp->top--;
-#else
 		if (!BN_sqr(tmp,a,ctx)) goto err;
-#endif
 		}
 	else
 		{
 		if (!BN_mul(tmp,a,b,ctx)) goto err;
 		}
 	/* reduce from aRR to aR */
+#ifdef MONT_WORD
+	if (!BN_from_montgomery_word(r,tmp,mont)) goto err;
+#else
 	if (!BN_from_montgomery(r,tmp,mont,ctx)) goto err;
+#endif
+	bn_check_top(r);
 	ret=1;
 err:
 	BN_CTX_end(ctx);
 	return(ret);
 	}
 
-int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
-	     BN_CTX *ctx)
-	{
-	int retn=0;
-
 #ifdef MONT_WORD
-	BIGNUM *n,*r;
+static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
+	{
+	BIGNUM *n;
 	BN_ULONG *ap,*np,*rp,n0,v,*nrp;
 	int al,nl,max,i,x,ri;
 
-	BN_CTX_start(ctx);
-	if ((r = BN_CTX_get(ctx)) == NULL) goto err;
-
-	if (!BN_copy(r,a)) goto err;
 	n= &(mont->N);
-
-	ap=a->d;
 	/* mont->ri is the size of mont->N in bits (rounded up
 	   to the word size) */
 	al=ri=mont->ri/BN_BITS2;
-	
+
 	nl=n->top;
-	if ((al == 0) || (nl == 0)) { r->top=0; return(1); }
+	if ((al == 0) || (nl == 0)) { ret->top=0; return(1); }
 
 	max=(nl+al+1); /* allow for overflow (no?) XXX */
-	if (bn_wexpand(r,max) == NULL) goto err;
-	if (bn_wexpand(ret,max) == NULL) goto err;
+	if (bn_wexpand(r,max) == NULL) return(0);
 
-	r->neg=a->neg^n->neg;
+	r->neg^=n->neg;
 	np=n->d;
 	rp=r->d;
 	nrp= &(r->d[nl]);
@@ -153,7 +155,7 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
 	n0=mont->n0;
 
 #ifdef BN_COUNT
-	printf("word BN_from_montgomery %d * %d\n",nl,nl);
+	fprintf(stderr,"word BN_from_montgomery_word %d * %d\n",nl,nl);
 #endif
 	for (i=0; i<nl; i++)
 		{
@@ -184,20 +186,24 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
 			for (x=2; (((++nrp[x])&BN_MASK2) == 0); x++) ;
 			}
 		}
-	bn_fix_top(r);
+	bn_correct_top(r);
 	
 	/* mont->ri will be a multiple of the word size */
 #if 0
 	BN_rshift(ret,r,mont->ri);
 #else
-	x=ri;
-	rp=ret->d;
-	ap= &(r->d[x]);
-	if (r->top < x)
-		al=0;
-	else
-		al=r->top-x;
+	if (r->top < ri)
+		{
+		ret->top=0;
+		return(1);
+		}
+	al=r->top-ri;
+	if (bn_wexpand(ret,al) == NULL) return(0);
+	ret->neg=r->neg;
 	ret->top=al;
+
+	rp=ret->d;
+	ap=&(r->d[ri]);
 	al-=4;
 	for (i=0; i<al; i+=4)
 		{
@@ -216,7 +222,29 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
 	for (; i<al; i++)
 		rp[i]=ap[i];
 #endif
-#else /* !MONT_WORD */ 
+
+	if (BN_ucmp(ret, &(mont->N)) >= 0)
+		{
+		if (!BN_usub(ret,ret,&(mont->N))) return(0);
+		}
+	bn_check_top(ret);
+
+	return(1);
+	}
+#endif	/* MONT_WORD */
+
+int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
+	     BN_CTX *ctx)
+	{
+	int retn=0;
+#ifdef MONT_WORD
+	BIGNUM *t;
+
+	BN_CTX_start(ctx);
+	if ((t = BN_CTX_get(ctx)) && BN_copy(t,a))
+		retn = BN_from_montgomery_word(ret,t,mont);
+	BN_CTX_end(ctx);
+#else /* !MONT_WORD */
 	BIGNUM *t1,*t2;
 
 	BN_CTX_start(ctx);
@@ -232,16 +260,17 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
 
 	if (!BN_mul(t1,t2,&mont->N,ctx)) goto err;
 	if (!BN_add(t2,a,t1)) goto err;
-	BN_rshift(ret,t2,mont->ri);
-#endif /* MONT_WORD */
+	if (!BN_rshift(ret,t2,mont->ri)) goto err;
 
 	if (BN_ucmp(ret, &(mont->N)) >= 0)
 		{
-		BN_usub(ret,ret,&(mont->N));
+		if (!BN_usub(ret,ret,&(mont->N))) goto err;
 		}
 	retn=1;
+	bn_check_top(ret);
  err:
 	BN_CTX_end(ctx);
+#endif /* MONT_WORD */
 	return(retn);
 	}
 
@@ -280,11 +309,14 @@ void BN_MONT_CTX_free(BN_MONT_CTX *mont)
 
 int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
 	{
-	BIGNUM Ri,*R;
+	int ret = 0;
+	BIGNUM *Ri,*R;
 
-	BN_init(&Ri);
+	BN_CTX_start(ctx);
+	if((Ri = BN_CTX_get(ctx)) == NULL) goto err;
 	R= &(mont->RR);					/* grab RR as a temp */
-	BN_copy(&(mont->N),mod);			/* Set N */
+	if (!BN_copy(&(mont->N),mod)) goto err;		/* Set N */
+	mont->N.neg = 0;
 
 #ifdef MONT_WORD
 		{
@@ -293,62 +325,84 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
 
 		mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
 		BN_zero(R);
-		BN_set_bit(R,BN_BITS2);			/* R */
+		if (!(BN_set_bit(R,BN_BITS2))) goto err;	/* R */
 
 		buf[0]=mod->d[0]; /* tmod = N mod word size */
 		buf[1]=0;
 		tmod.d=buf;
-		tmod.top=1;
+		tmod.top = buf[0] != 0 ? 1 : 0;
 		tmod.dmax=2;
-		tmod.neg=mod->neg;
+		tmod.neg=0;
 							/* Ri = R^-1 mod N*/
-		if ((BN_mod_inverse(&Ri,R,&tmod,ctx)) == NULL)
+		if ((BN_mod_inverse(Ri,R,&tmod,ctx)) == NULL)
 			goto err;
-		BN_lshift(&Ri,&Ri,BN_BITS2);		/* R*Ri */
-		if (!BN_is_zero(&Ri))
-			BN_sub_word(&Ri,1);
+		if (!BN_lshift(Ri,Ri,BN_BITS2)) goto err; /* R*Ri */
+		if (!BN_is_zero(Ri))
+			{
+			if (!BN_sub_word(Ri,1)) goto err;
+			}
 		else /* if N mod word size == 1 */
-			BN_set_word(&Ri,BN_MASK2);  /* Ri-- (mod word size) */
-		BN_div(&Ri,NULL,&Ri,&tmod,ctx);	/* Ni = (R*Ri-1)/N,
-		                                 * keep only least significant word: */
-		mont->n0=Ri.d[0];
-		BN_free(&Ri);
+			{
+			if (!BN_set_word(Ri,BN_MASK2)) goto err;  /* Ri-- (mod word size) */
+			}
+		if (!BN_div(Ri,NULL,Ri,&tmod,ctx)) goto err;
+		/* Ni = (R*Ri-1)/N,
+		 * keep only least significant word: */
+		mont->n0 = (Ri->top > 0) ? Ri->d[0] : 0;
 		}
 #else /* !MONT_WORD */
 		{ /* bignum version */
-		mont->ri=BN_num_bits(mod);
+		mont->ri=BN_num_bits(&mont->N);
 		BN_zero(R);
-		BN_set_bit(R,mont->ri);			/* R = 2^ri */
-							/* Ri = R^-1 mod N*/
-		if ((BN_mod_inverse(&Ri,R,mod,ctx)) == NULL)
+		if (!BN_set_bit(R,mont->ri)) goto err;  /* R = 2^ri */
+		                                        /* Ri = R^-1 mod N*/
+		if ((BN_mod_inverse(Ri,R,&mont->N,ctx)) == NULL)
 			goto err;
-		BN_lshift(&Ri,&Ri,mont->ri);		/* R*Ri */
-		BN_sub_word(&Ri,1);
+		if (!BN_lshift(Ri,Ri,mont->ri)) goto err; /* R*Ri */
+		if (!BN_sub_word(Ri,1)) goto err;
 							/* Ni = (R*Ri-1) / N */
-		BN_div(&(mont->Ni),NULL,&Ri,mod,ctx);
-		BN_free(&Ri);
+		if (!BN_div(&(mont->Ni),NULL,Ri,&mont->N,ctx)) goto err;
 		}
 #endif
 
 	/* setup RR for conversions */
 	BN_zero(&(mont->RR));
-	BN_set_bit(&(mont->RR),mont->ri*2);
-	BN_mod(&(mont->RR),&(mont->RR),&(mont->N),ctx);
+	if (!BN_set_bit(&(mont->RR),mont->ri*2)) goto err;
+	if (!BN_mod(&(mont->RR),&(mont->RR),&(mont->N),ctx)) goto err;
 
-	return(1);
+	ret = 1;
 err:
-	return(0);
+	BN_CTX_end(ctx);
+	return ret;
 	}
 
 BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from)
 	{
 	if (to == from) return(to);
 
-	BN_copy(&(to->RR),&(from->RR));
-	BN_copy(&(to->N),&(from->N));
-	BN_copy(&(to->Ni),&(from->Ni));
+	if (!BN_copy(&(to->RR),&(from->RR))) return NULL;
+	if (!BN_copy(&(to->N),&(from->N))) return NULL;
+	if (!BN_copy(&(to->Ni),&(from->Ni))) return NULL;
 	to->ri=from->ri;
 	to->n0=from->n0;
 	return(to);
 	}
 
+BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, int lock,
+					const BIGNUM *mod, BN_CTX *ctx)
+	{
+	if (*pmont)
+		return *pmont;
+	CRYPTO_w_lock(lock);
+	if (!*pmont)
+		{
+		*pmont = BN_MONT_CTX_new();
+		if (*pmont && !BN_MONT_CTX_set(*pmont, mod, ctx))
+			{
+			BN_MONT_CTX_free(*pmont);
+			*pmont = NULL;
+			}
+		}
+	CRYPTO_w_unlock(lock);
+	return *pmont;
+	}