#define MONT_WORD /* use the faster word-based algorithm */
+#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;
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);
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, const 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]);
#endif
r->top=max;
- n0=mont->n0;
+ n0=mont->n0[0];
#ifdef BN_COUNT
- fprintf(stderr,"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++)
{
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
- ret->neg = r->neg;
- 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)
{
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);
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)
{
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);
}
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
BIGNUM tmod;
BN_ULONG buf[2];
+ tmod.d=buf;
+ tmod.dmax=2;
+ tmod.neg=0;
+
mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
+
+#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)
BN_zero(R);
- BN_set_bit(R,BN_BITS2); /* R */
+ if (!(BN_set_bit(R,2*BN_BITS2))) goto err;
+
+ tmod.top=0;
+ if ((buf[0] = mod->d[0])) tmod.top=1;
+ if ((buf[1] = mod->top>1 ? mod->d[1] : 0)) tmod.top=2;
+
+ if ((BN_mod_inverse(Ri,R,&tmod,ctx)) == NULL)
+ goto err;
+ if (!BN_lshift(Ri,Ri,2*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 */
+ {
+ if (bn_expand(Ri,(int)sizeof(BN_ULONG)*2) == NULL)
+ goto err;
+ /* Ri-- (mod double word size) */
+ Ri->neg=0;
+ Ri->d[0]=BN_MASK2;
+ Ri->d[1]=BN_MASK2;
+ Ri->top=2;
+ }
+ if (!BN_div(Ri,NULL,Ri,&tmod,ctx)) goto err;
+ /* Ni = (R*Ri-1)/N,
+ * keep only couple of least significant words: */
+ mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
+ mont->n0[1] = (Ri->top > 1) ? Ri->d[1] : 0;
+#else
+ BN_zero(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.dmax=2;
- tmod.neg=0;
+ tmod.top = buf[0] != 0 ? 1 : 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;
- if (!BN_lshift(&Ri,&Ri,BN_BITS2)) goto err; /* R*Ri */
- if (!BN_is_zero(&Ri))
+ if (!BN_lshift(Ri,Ri,BN_BITS2)) goto err; /* R*Ri */
+ if (!BN_is_zero(Ri))
{
- if (!BN_sub_word(&Ri,1)) goto err;
+ if (!BN_sub_word(Ri,1)) goto err;
}
else /* if N mod word size == 1 */
{
- if (!BN_set_word(&Ri,BN_MASK2)) goto err; /* Ri-- (mod word size) */
+ if (!BN_set_word(Ri,BN_MASK2)) goto err; /* Ri-- (mod word size) */
}
- if (!BN_div(&Ri,NULL,&Ri,&tmod,ctx)) goto err;
+ 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;
- BN_free(&Ri);
+ mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
+ mont->n0[1] = 0;
+#endif
}
#else /* !MONT_WORD */
{ /* bignum version */
mont->ri=BN_num_bits(&mont->N);
- if (!BN_zero(R)) goto err;
+ BN_zero(R);
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)
+ if ((BN_mod_inverse(Ri,R,&mont->N,ctx)) == NULL)
goto err;
- if (!BN_lshift(&Ri,&Ri,mont->ri)) goto err; /* R*Ri */
- if (!BN_sub_word(&Ri,1)) goto err;
+ if (!BN_lshift(Ri,Ri,mont->ri)) goto err; /* R*Ri */
+ if (!BN_sub_word(Ri,1)) goto err;
/* Ni = (R*Ri-1) / N */
- if (!BN_div(&(mont->Ni),NULL,&Ri,&mont->N,ctx)) goto err;
- BN_free(&Ri);
+ if (!BN_div(&(mont->Ni),NULL,Ri,&mont->N,ctx)) goto err;
}
#endif
/* setup RR for conversions */
- if (!BN_zero(&(mont->RR))) goto err;
+ BN_zero(&(mont->RR));
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 (!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;
+ to->n0[0]=from->n0[0];
+ to->n0[1]=from->n0[1];
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;
+ }
projects / openssl.git / blobdiff