1 files changed, 246 insertions, 76 deletions

diff --git a/src/lib/libcrypto/bn/bn_asm.c b/src/lib/libcrypto/bn/bn_asm.c
index 99bc2de491..c43c91cc09 100644
--- a/src/lib/libcrypto/bn/bn_asm.c
+++ b/src/lib/libcrypto/bn/bn_asm.c
@@ -75,6 +75,7 @@ BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
         assert(num >= 0);
         if (num <= 0) return(c1);
 
+#ifndef OPENSSL_SMALL_FOOTPRINT
         while (num&~3)
                 {
                 mul_add(rp[0],ap[0],w,c1);
@@ -83,11 +84,11 @@ BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
                 mul_add(rp[3],ap[3],w,c1);
                 ap+=4; rp+=4; num-=4;
                 }
-        if (num)
+#endif
+        while (num)
                 {
-                mul_add(rp[0],ap[0],w,c1); if (--num==0) return c1;
-                mul_add(rp[1],ap[1],w,c1); if (--num==0) return c1;
-                mul_add(rp[2],ap[2],w,c1); return c1;
+                mul_add(rp[0],ap[0],w,c1);
+                ap++; rp++; num--;
                 }
         
         return(c1);
@@ -100,6 +101,7 @@ BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
         assert(num >= 0);
         if (num <= 0) return(c1);
 
+#ifndef OPENSSL_SMALL_FOOTPRINT
         while (num&~3)
                 {
                 mul(rp[0],ap[0],w,c1);
@@ -108,11 +110,11 @@ BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
                 mul(rp[3],ap[3],w,c1);
                 ap+=4; rp+=4; num-=4;
                 }
-        if (num)
+#endif
+        while (num)
                 {
-                mul(rp[0],ap[0],w,c1); if (--num == 0) return c1;
-                mul(rp[1],ap[1],w,c1); if (--num == 0) return c1;
-                mul(rp[2],ap[2],w,c1);
+                mul(rp[0],ap[0],w,c1);
+                ap++; rp++; num--;
                 }
         return(c1);
         } 
@@ -121,6 +123,8 @@ void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
         {
         assert(n >= 0);
         if (n <= 0) return;
+
+#ifndef OPENSSL_SMALL_FOOTPRINT
         while (n&~3)
                 {
                 sqr(r[0],r[1],a[0]);
@@ -129,11 +133,11 @@ void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
                 sqr(r[6],r[7],a[3]);
                 a+=4; r+=8; n-=4;
                 }
-        if (n)
+#endif
+        while (n)
                 {
-                sqr(r[0],r[1],a[0]); if (--n == 0) return;
-                sqr(r[2],r[3],a[1]); if (--n == 0) return;
-                sqr(r[4],r[5],a[2]);
+                sqr(r[0],r[1],a[0]);
+                a++; r+=2; n--;
                 }
         }
 
@@ -150,18 +154,20 @@ BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
         bl=LBITS(w);
         bh=HBITS(w);
 
-        for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (num&~3)
                 {
                 mul_add(rp[0],ap[0],bl,bh,c);
-                if (--num == 0) break;
                 mul_add(rp[1],ap[1],bl,bh,c);
-                if (--num == 0) break;
                 mul_add(rp[2],ap[2],bl,bh,c);
-                if (--num == 0) break;
                 mul_add(rp[3],ap[3],bl,bh,c);
-                if (--num == 0) break;
-                ap+=4;
-                rp+=4;
+                ap+=4; rp+=4; num-=4;
+                }
+#endif
+        while (num)
+                {
+                mul_add(rp[0],ap[0],bl,bh,c);
+                ap++; rp++; num--;
                 }
         return(c);
         } 
@@ -177,18 +183,20 @@ BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
         bl=LBITS(w);
         bh=HBITS(w);
 
-        for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (num&~3)
                 {
                 mul(rp[0],ap[0],bl,bh,carry);
-                if (--num == 0) break;
                 mul(rp[1],ap[1],bl,bh,carry);
-                if (--num == 0) break;
                 mul(rp[2],ap[2],bl,bh,carry);
-                if (--num == 0) break;
                 mul(rp[3],ap[3],bl,bh,carry);
-                if (--num == 0) break;
-                ap+=4;
-                rp+=4;
+                ap+=4; rp+=4; num-=4;
+                }
+#endif
+        while (num)
+                {
+                mul(rp[0],ap[0],bl,bh,carry);
+                ap++; rp++; num--;
                 }
         return(carry);
         } 
@@ -197,22 +205,21 @@ void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
         {
         assert(n >= 0);
         if (n <= 0) return;
-        for (;;)
+
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (n&~3)
                 {
                 sqr64(r[0],r[1],a[0]);
-                if (--n == 0) break;
-
                 sqr64(r[2],r[3],a[1]);
-                if (--n == 0) break;
-
                 sqr64(r[4],r[5],a[2]);
-                if (--n == 0) break;
-
                 sqr64(r[6],r[7],a[3]);
-                if (--n == 0) break;
-
-                a+=4;
-                r+=8;
+                a+=4; r+=8; n-=4;
+                }
+#endif
+        while (n)
+                {
+                sqr64(r[0],r[1],a[0]);
+                a++; r+=2; n--;
                 }
         }
 
@@ -303,31 +310,30 @@ BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
         assert(n >= 0);
         if (n <= 0) return((BN_ULONG)0);
 
-        for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (n&~3)
                 {
                 ll+=(BN_ULLONG)a[0]+b[0];
                 r[0]=(BN_ULONG)ll&BN_MASK2;
                 ll>>=BN_BITS2;
-                if (--n <= 0) break;
-
                 ll+=(BN_ULLONG)a[1]+b[1];
                 r[1]=(BN_ULONG)ll&BN_MASK2;
                 ll>>=BN_BITS2;
-                if (--n <= 0) break;
-
                 ll+=(BN_ULLONG)a[2]+b[2];
                 r[2]=(BN_ULONG)ll&BN_MASK2;
                 ll>>=BN_BITS2;
-                if (--n <= 0) break;
-
                 ll+=(BN_ULLONG)a[3]+b[3];
                 r[3]=(BN_ULONG)ll&BN_MASK2;
                 ll>>=BN_BITS2;
-                if (--n <= 0) break;
-
-                a+=4;
-                b+=4;
-                r+=4;
+                a+=4; b+=4; r+=4; n-=4;
+                }
+#endif
+        while (n)
+                {
+                ll+=(BN_ULLONG)a[0]+b[0];
+                r[0]=(BN_ULONG)ll&BN_MASK2;
+                ll>>=BN_BITS2;
+                a++; b++; r++; n--;
                 }
         return((BN_ULONG)ll);
         }
@@ -340,7 +346,8 @@ BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
         if (n <= 0) return((BN_ULONG)0);
 
         c=0;
-        for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (n&~3)
                 {
                 t=a[0];
                 t=(t+c)&BN_MASK2;
@@ -348,35 +355,36 @@ BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
                 l=(t+b[0])&BN_MASK2;
                 c+=(l < t);
                 r[0]=l;
-                if (--n <= 0) break;
-
                 t=a[1];
                 t=(t+c)&BN_MASK2;
                 c=(t < c);
                 l=(t+b[1])&BN_MASK2;
                 c+=(l < t);
                 r[1]=l;
-                if (--n <= 0) break;
-
                 t=a[2];
                 t=(t+c)&BN_MASK2;
                 c=(t < c);
                 l=(t+b[2])&BN_MASK2;
                 c+=(l < t);
                 r[2]=l;
-                if (--n <= 0) break;
-
                 t=a[3];
                 t=(t+c)&BN_MASK2;
                 c=(t < c);
                 l=(t+b[3])&BN_MASK2;
                 c+=(l < t);
                 r[3]=l;
-                if (--n <= 0) break;
-
-                a+=4;
-                b+=4;
-                r+=4;
+                a+=4; b+=4; r+=4; n-=4;
+                }
+#endif
+        while(n)
+                {
+                t=a[0];
+                t=(t+c)&BN_MASK2;
+                c=(t < c);
+                l=(t+b[0])&BN_MASK2;
+                c+=(l < t);
+                r[0]=l;
+                a++; b++; r++; n--;
                 }
         return((BN_ULONG)c);
         }
@@ -390,36 +398,35 @@ BN_ULONG bn_sub_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
         assert(n >= 0);
         if (n <= 0) return((BN_ULONG)0);
 
-        for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (n&~3)
                 {
                 t1=a[0]; t2=b[0];
                 r[0]=(t1-t2-c)&BN_MASK2;
                 if (t1 != t2) c=(t1 < t2);
-                if (--n <= 0) break;
-
                 t1=a[1]; t2=b[1];
                 r[1]=(t1-t2-c)&BN_MASK2;
                 if (t1 != t2) c=(t1 < t2);
-                if (--n <= 0) break;
-
                 t1=a[2]; t2=b[2];
                 r[2]=(t1-t2-c)&BN_MASK2;
                 if (t1 != t2) c=(t1 < t2);
-                if (--n <= 0) break;
-
                 t1=a[3]; t2=b[3];
                 r[3]=(t1-t2-c)&BN_MASK2;
                 if (t1 != t2) c=(t1 < t2);
-                if (--n <= 0) break;
-
-                a+=4;
-                b+=4;
-                r+=4;
+                a+=4; b+=4; r+=4; n-=4;
+                }
+#endif
+        while (n)
+                {
+                t1=a[0]; t2=b[0];
+                r[0]=(t1-t2-c)&BN_MASK2;
+                if (t1 != t2) c=(t1 < t2);
+                a++; b++; r++; n--;
                 }
         return(c);
         }
 
-#ifdef BN_MUL_COMBA
+#if defined(BN_MUL_COMBA) && !defined(OPENSSL_SMALL_FOOTPRINT)
 
 #undef bn_mul_comba8
 #undef bn_mul_comba4
@@ -820,18 +827,134 @@ void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a)
         r[6]=c1;
         r[7]=c2;
         }
+
+#ifdef OPENSSL_NO_ASM
+#ifdef OPENSSL_BN_ASM_MONT
+#include <alloca.h>
+/*
+ * This is essentially reference implementation, which may or may not
+ * result in performance improvement. E.g. on IA-32 this routine was
+ * observed to give 40% faster rsa1024 private key operations and 10%
+ * faster rsa4096 ones, while on AMD64 it improves rsa1024 sign only
+ * by 10% and *worsens* rsa4096 sign by 15%. Once again, it's a
+ * reference implementation, one to be used as starting point for
+ * platform-specific assembler. Mentioned numbers apply to compiler
+ * generated code compiled with and without -DOPENSSL_BN_ASM_MONT and
+ * can vary not only from platform to platform, but even for compiler
+ * versions. Assembler vs. assembler improvement coefficients can
+ * [and are known to] differ and are to be documented elsewhere.
+ */
+int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np,const BN_ULONG *n0p, int num)
+        {
+        BN_ULONG c0,c1,ml,*tp,n0;
+#ifdef mul64
+        BN_ULONG mh;
+#endif
+        volatile BN_ULONG *vp;
+        int i=0,j;
+
+#if 0   /* template for platform-specific implementation */
+        if (ap==bp)     return bn_sqr_mont(rp,ap,np,n0p,num);
+#endif
+        vp = tp = alloca((num+2)*sizeof(BN_ULONG));
+
+        n0 = *n0p;
+
+        c0 = 0;
+        ml = bp[0];
+#ifdef mul64
+        mh = HBITS(ml);
+        ml = LBITS(ml);
+        for (j=0;j<num;++j)
+                mul(tp[j],ap[j],ml,mh,c0);
+#else
+        for (j=0;j<num;++j)
+                mul(tp[j],ap[j],ml,c0);
+#endif
+
+        tp[num]   = c0;
+        tp[num+1] = 0;
+        goto enter;
+
+        for(i=0;i<num;i++)
+                {
+                c0 = 0;
+                ml = bp[i];
+#ifdef mul64
+                mh = HBITS(ml);
+                ml = LBITS(ml);
+                for (j=0;j<num;++j)
+                        mul_add(tp[j],ap[j],ml,mh,c0);
+#else
+                for (j=0;j<num;++j)
+                        mul_add(tp[j],ap[j],ml,c0);
+#endif
+                c1 = (tp[num] + c0)&BN_MASK2;
+                tp[num]   = c1;
+                tp[num+1] = (c1<c0?1:0);
+        enter:
+                c1  = tp[0];
+                ml = (c1*n0)&BN_MASK2;
+                c0 = 0;
+#ifdef mul64
+                mh = HBITS(ml);
+                ml = LBITS(ml);
+                mul_add(c1,np[0],ml,mh,c0);
+#else
+                mul_add(c1,ml,np[0],c0);
+#endif
+                for(j=1;j<num;j++)
+                        {
+                        c1 = tp[j];
+#ifdef mul64
+                        mul_add(c1,np[j],ml,mh,c0);
+#else
+                        mul_add(c1,ml,np[j],c0);
+#endif
+                        tp[j-1] = c1&BN_MASK2;
+                        }
+                c1        = (tp[num] + c0)&BN_MASK2;
+                tp[num-1] = c1;
+                tp[num]   = tp[num+1] + (c1<c0?1:0);
+                }
+
+        if (tp[num]!=0 || tp[num-1]>=np[num-1])
+                {
+                c0 = bn_sub_words(rp,tp,np,num);
+                if (tp[num]!=0 || c0==0)
+                        {
+                        for(i=0;i<num+2;i++)    vp[i] = 0;
+                        return 1;
+                        }
+                }
+        for(i=0;i<num;i++)      rp[i] = tp[i],  vp[i] = 0;
+        vp[num]   = 0;
+        vp[num+1] = 0;
+        return 1;
+        }
+#else
+/*
+ * Return value of 0 indicates that multiplication/convolution was not
+ * performed to signal the caller to fall down to alternative/original
+ * code-path.
+ */
+int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np,const BN_ULONG *n0, int num)
+{       return 0;       }
+#endif /* OPENSSL_BN_ASM_MONT */
+#endif
+
 #else /* !BN_MUL_COMBA */
 
 /* hmm... is it faster just to do a multiply? */
 #undef bn_sqr_comba4
-void bn_sqr_comba4(BN_ULONG *r, BN_ULONG *a)
+void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a)
         {
         BN_ULONG t[8];
         bn_sqr_normal(r,a,4,t);
         }
 
 #undef bn_sqr_comba8
-void bn_sqr_comba8(BN_ULONG *r, BN_ULONG *a)
+void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a)
         {
         BN_ULONG t[16];
         bn_sqr_normal(r,a,8,t);
@@ -857,4 +980,51 @@ void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
         r[15]=bn_mul_add_words(&(r[7]),a,8,b[7]);
         }
 
+#ifdef OPENSSL_NO_ASM
+#ifdef OPENSSL_BN_ASM_MONT
+#include <alloca.h>
+int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np,const BN_ULONG *n0p, int num)
+        {
+        BN_ULONG c0,c1,*tp,n0=*n0p;
+        volatile BN_ULONG *vp;
+        int i=0,j;
+
+        vp = tp = alloca((num+2)*sizeof(BN_ULONG));
+
+        for(i=0;i<=num;i++)     tp[i]=0;
+
+        for(i=0;i<num;i++)
+                {
+                c0         = bn_mul_add_words(tp,ap,num,bp[i]);
+                c1         = (tp[num] + c0)&BN_MASK2;
+                tp[num]    = c1;
+                tp[num+1]  = (c1<c0?1:0);
+
+                c0         = bn_mul_add_words(tp,np,num,tp[0]*n0);
+                c1         = (tp[num] + c0)&BN_MASK2;
+                tp[num]    = c1;
+                tp[num+1] += (c1<c0?1:0);
+                for(j=0;j<=num;j++)     tp[j]=tp[j+1];
+                }
+
+        if (tp[num]!=0 || tp[num-1]>=np[num-1])
+                {
+                c0 = bn_sub_words(rp,tp,np,num);
+                if (tp[num]!=0 || c0==0)
+                        {
+                        for(i=0;i<num+2;i++)    vp[i] = 0;
+                        return 1;
+                        }
+                }
+        for(i=0;i<num;i++)      rp[i] = tp[i],  vp[i] = 0;
+        vp[num]   = 0;
+        vp[num+1] = 0;
+        return 1;
+        }
+#else
+int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np,const BN_ULONG *n0, int num)
+{       return 0;       }
+#endif /* OPENSSL_BN_ASM_MONT */
+#endif
+
 #endif /* !BN_MUL_COMBA */