1 files changed, 52 insertions, 217 deletions

diff --git a/src/lib/libcrypto/bn/bn_mont.c b/src/lib/libcrypto/bn/bn_mont.c
index 4799b152dd..7224637ab3 100644
--- a/src/lib/libcrypto/bn/bn_mont.c
+++ b/src/lib/libcrypto/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);
         }