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path: root/openssl/crypto/bn/bn_mont.c
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Diffstat (limited to 'openssl/crypto/bn/bn_mont.c')
-rw-r--r--openssl/crypto/bn/bn_mont.c269
1 files changed, 52 insertions, 217 deletions
diff --git a/openssl/crypto/bn/bn_mont.c b/openssl/crypto/bn/bn_mont.c
index 4799b152d..7224637ab 100644
--- a/openssl/crypto/bn/bn_mont.c
+++ b/openssl/crypto/bn/bn_mont.c
@@ -122,26 +122,10 @@
#define MONT_WORD /* use the faster word-based algorithm */
-#if defined(MONT_WORD) && defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)
-/* This condition means we have a specific non-default build:
- * In the 0.9.8 branch, OPENSSL_BN_ASM_MONT is normally not set for any
- * BN_BITS2<=32 platform; an explicit "enable-montasm" is required.
- * I.e., if we are here, the user intentionally deviates from the
- * normal stable build to get better Montgomery performance from
- * the 0.9.9-dev backport.
- *
- * In this case only, we also enable BN_from_montgomery_word()
- * (another non-stable feature from 0.9.9-dev).
- */
-#define MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD
-#endif
-
-#ifdef MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD
+#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)
{
@@ -153,11 +137,7 @@ int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
if (num>1 && a->top==num && b->top==num)
{
if (bn_wexpand(r,num) == NULL) return(0);
-#if 0 /* for OpenSSL 0.9.9 mont->n0 */
if (bn_mul_mont(r->d,a->d,b->d,mont->N.d,mont->n0,num))
-#else
- if (bn_mul_mont(r->d,a->d,b->d,mont->N.d,&mont->n0,num))
-#endif
{
r->neg = a->neg^b->neg;
r->top = num;
@@ -181,7 +161,7 @@ int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
if (!BN_mul(tmp,a,b,ctx)) goto err;
}
/* reduce from aRR to aR */
-#ifdef MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD
+#ifdef MONT_WORD
if (!BN_from_montgomery_word(r,tmp,mont)) goto err;
#else
if (!BN_from_montgomery(r,tmp,mont,ctx)) goto err;
@@ -193,7 +173,7 @@ err:
return(ret);
}
-#ifdef MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD
+#ifdef MONT_WORD
static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
{
BIGNUM *n;
@@ -217,15 +197,15 @@ static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
nrp= &(r->d[nl]);
/* clear the top words of T */
+#if 1
for (i=r->top; i<max; i++) /* memset? XXX */
r->d[i]=0;
+#else
+ memset(&(r->d[r->top]),0,(max-r->top)*sizeof(BN_ULONG));
+#endif
r->top=max;
-#if 0 /* for OpenSSL 0.9.9 mont->n0 */
n0=mont->n0[0];
-#else
- n0=mont->n0;
-#endif
#ifdef BN_COUNT
fprintf(stderr,"word BN_from_montgomery_word %d * %d\n",nl,nl);
@@ -270,6 +250,8 @@ static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
}
al=r->top-ri;
+#define BRANCH_FREE 1
+#if BRANCH_FREE
if (bn_wexpand(ret,ri) == NULL) return(0);
x=0-(((al-ri)>>(sizeof(al)*8-1))&1);
ret->top=x=(ri&~x)|(al&x); /* min(ri,al) */
@@ -317,164 +299,8 @@ static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
rp[i]=nrp[i], ap[i]=0;
bn_correct_top(r);
bn_correct_top(ret);
- bn_check_top(ret);
-
- return(1);
- }
-
-int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
- BN_CTX *ctx)
- {
- int retn=0;
- 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);
- return retn;
- }
-
-#else /* !MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD */
-
-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;
- 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); }
-
- max=(nl+al+1); /* allow for overflow (no?) XXX */
- if (bn_wexpand(r,max) == NULL) goto err;
-
- r->neg=a->neg^n->neg;
- np=n->d;
- rp=r->d;
- nrp= &(r->d[nl]);
-
- /* clear the top words of T */
-#if 1
- for (i=r->top; i<max; i++) /* memset? XXX */
- r->d[i]=0;
#else
- memset(&(r->d[r->top]),0,(max-r->top)*sizeof(BN_ULONG));
-#endif
-
- r->top=max;
- n0=mont->n0;
-
-#ifdef BN_COUNT
- fprintf(stderr,"word BN_from_montgomery %d * %d\n",nl,nl);
-#endif
- for (i=0; i<nl; i++)
- {
-#ifdef __TANDEM
- {
- long long t1;
- long long t2;
- long long t3;
- t1 = rp[0] * (n0 & 0177777);
- t2 = 037777600000l;
- t2 = n0 & t2;
- t3 = rp[0] & 0177777;
- t2 = (t3 * t2) & BN_MASK2;
- t1 = t1 + t2;
- v=bn_mul_add_words(rp,np,nl,(BN_ULONG) t1);
- }
-#else
- v=bn_mul_add_words(rp,np,nl,(rp[0]*n0)&BN_MASK2);
-#endif
- nrp++;
- rp++;
- if (((nrp[-1]+=v)&BN_MASK2) >= v)
- continue;
- else
- {
- if (((++nrp[0])&BN_MASK2) != 0) continue;
- if (((++nrp[1])&BN_MASK2) != 0) continue;
- for (x=2; (((++nrp[x])&BN_MASK2) == 0); x++) ;
- }
- }
- bn_correct_top(r);
-
- /* mont->ri will be a multiple of the word size and below code
- * is kind of BN_rshift(ret,r,mont->ri) equivalent */
- if (r->top <= ri)
- {
- ret->top=0;
- retn=1;
- goto err;
- }
- al=r->top-ri;
-
-# define BRANCH_FREE 1
-# if BRANCH_FREE
- if (bn_wexpand(ret,ri) == NULL) goto err;
- x=0-(((al-ri)>>(sizeof(al)*8-1))&1);
- ret->top=x=(ri&~x)|(al&x); /* min(ri,al) */
- ret->neg=r->neg;
-
- rp=ret->d;
- ap=&(r->d[ri]);
-
- {
- size_t m1,m2;
-
- v=bn_sub_words(rp,ap,np,ri);
- /* this ----------------^^ works even in al<ri case
- * thanks to zealous zeroing of top of the vector in the
- * beginning. */
-
- /* if (al==ri && !v) || al>ri) nrp=rp; else nrp=ap; */
- /* in other words if subtraction result is real, then
- * trick unconditional memcpy below to perform in-place
- * "refresh" instead of actual copy. */
- m1=0-(size_t)(((al-ri)>>(sizeof(al)*8-1))&1); /* al<ri */
- m2=0-(size_t)(((ri-al)>>(sizeof(al)*8-1))&1); /* al>ri */
- m1|=m2; /* (al!=ri) */
- m1|=(0-(size_t)v); /* (al!=ri || v) */
- m1&=~m2; /* (al!=ri || v) && !al>ri */
- nrp=(BN_ULONG *)(((size_t)rp&~m1)|((size_t)ap&m1));
- }
-
- /* 'i<ri' is chosen to eliminate dependency on input data, even
- * though it results in redundant copy in al<ri case. */
- for (i=0,ri-=4; i<ri; i+=4)
- {
- BN_ULONG t1,t2,t3,t4;
-
- t1=nrp[i+0];
- t2=nrp[i+1];
- t3=nrp[i+2]; ap[i+0]=0;
- t4=nrp[i+3]; ap[i+1]=0;
- rp[i+0]=t1; ap[i+2]=0;
- rp[i+1]=t2; ap[i+3]=0;
- rp[i+2]=t3;
- rp[i+3]=t4;
- }
- for (ri+=4; i<ri; i++)
- rp[i]=nrp[i], ap[i]=0;
- bn_correct_top(r);
- bn_correct_top(ret);
-# else
- if (bn_wexpand(ret,al) == NULL) goto err;
+ if (bn_wexpand(ret,al) == NULL) return(0);
ret->top=al;
ret->neg=r->neg;
@@ -497,8 +323,30 @@ int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
al+=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);
+ }
+#endif
+ 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);
@@ -515,21 +363,18 @@ int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
if (!BN_mul(t1,t2,&mont->N,ctx)) goto err;
if (!BN_add(t2,a,t1)) goto err;
if (!BN_rshift(ret,t2,mont->ri)) goto err;
-#endif /* MONT_WORD */
-#if !defined(BRANCH_FREE) || BRANCH_FREE==0
if (BN_ucmp(ret, &(mont->N)) >= 0)
{
if (!BN_usub(ret,ret,&(mont->N))) goto err;
}
-#endif
retn=1;
bn_check_top(ret);
err:
BN_CTX_end(ctx);
+#endif /* MONT_WORD */
return(retn);
}
-#endif /* MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD */
BN_MONT_CTX *BN_MONT_CTX_new(void)
{
@@ -549,11 +394,7 @@ void BN_MONT_CTX_init(BN_MONT_CTX *ctx)
BN_init(&(ctx->RR));
BN_init(&(ctx->N));
BN_init(&(ctx->Ni));
-#if 0 /* for OpenSSL 0.9.9 mont->n0 */
ctx->n0[0] = ctx->n0[1] = 0;
-#else
- ctx->n0 = 0;
-#endif
ctx->flags=0;
}
@@ -585,26 +426,22 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
BIGNUM tmod;
BN_ULONG buf[2];
- mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
- BN_zero(R);
-#if 0 /* for OpenSSL 0.9.9 mont->n0, would be "#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)",
- only certain BN_BITS2<=32 platforms actually need this */
- if (!(BN_set_bit(R,2*BN_BITS2))) goto err; /* R */
-#else
- if (!(BN_set_bit(R,BN_BITS2))) goto err; /* R */
-#endif
-
- buf[0]=mod->d[0]; /* tmod = N mod word size */
- buf[1]=0;
-
BN_init(&tmod);
tmod.d=buf;
- tmod.top = buf[0] != 0 ? 1 : 0;
tmod.dmax=2;
tmod.neg=0;
-#if 0 /* for OpenSSL 0.9.9 mont->n0, would be "#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)";
- only certain BN_BITS2<=32 platforms actually need this */
+ mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
+
+#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)
+ /* Only certain BN_BITS2<=32 platforms actually make use of
+ * n0[1], and we could use the #else case (with a shorter R
+ * value) for the others. However, currently only the assembler
+ * files do know which is which. */
+
+ BN_zero(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;
@@ -632,6 +469,12 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
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.top = buf[0] != 0 ? 1 : 0;
/* Ri = R^-1 mod N*/
if ((BN_mod_inverse(Ri,R,&tmod,ctx)) == NULL)
goto err;
@@ -647,12 +490,8 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
if (!BN_div(Ri,NULL,Ri,&tmod,ctx)) goto err;
/* Ni = (R*Ri-1)/N,
* keep only least significant word: */
-# if 0 /* for OpenSSL 0.9.9 mont->n0 */
mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
mont->n0[1] = 0;
-# else
- mont->n0 = (Ri->top > 0) ? Ri->d[0] : 0;
-# endif
#endif
}
#else /* !MONT_WORD */
@@ -689,12 +528,8 @@ 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;
-#if 0 /* for OpenSSL 0.9.9 mont->n0 */
to->n0[0]=from->n0[0];
to->n0[1]=from->n0[1];
-#else
- to->n0=from->n0;
-#endif
return(to);
}