OpenSSL 0.9.4 merge

1 files changed, 271 insertions, 170 deletions

diff --git a/src/lib/libcrypto/bn/bn_mont.c b/src/lib/libcrypto/bn/bn_mont.c
index e435df61f8..ee0f410c22 100644
--- a/src/lib/libcrypto/bn/bn_mont.c
+++ b/src/lib/libcrypto/bn/bn_mont.c
@@ -56,251 +56,352 @@
  * [including the GNU Public Licence.]
  */
 
+/*
+ * Details about Montgomery multiplication algorithms can be found at:
+ * http://www.ece.orst.edu/ISL/Publications.html
+ * http://www.ece.orst.edu/ISL/Koc/papers/j37acmon.pdf
+ */
+
 #include <stdio.h>
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
-int BN_mod_mul_montgomery(r,a,b,mont,ctx)
-BIGNUM *r,*a,*b;
-BN_MONT_CTX *mont;
-BN_CTX *ctx;
+#define MONT_WORD
+
+int BN_mod_mul_montgomery(BIGNUM *r, BIGNUM *a, BIGNUM *b,
+                          BN_MONT_CTX *mont, BN_CTX *ctx)
         {
-        BIGNUM *tmp;
+        BIGNUM *tmp,*tmp2;
+
+        tmp= &(ctx->bn[ctx->tos]);
+        tmp2= &(ctx->bn[ctx->tos]);
+        ctx->tos+=2;
 
-        tmp=ctx->bn[ctx->tos++];
+        bn_check_top(tmp);
+        bn_check_top(tmp2);
 
         if (a == b)
                 {
+#if 0
+                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->d[tmp->top-1] == 0)
+                        tmp->top--;
+#else
                 if (!BN_sqr(tmp,a,ctx)) goto err;
+#endif
                 }
         else
                 {
-                if (!BN_mul(tmp,a,b)) goto err;
+                if (!BN_mul(tmp,a,b,ctx)) goto err;
                 }
         /* reduce from aRR to aR */
         if (!BN_from_montgomery(r,tmp,mont,ctx)) goto err;
-        ctx->tos--;
+        ctx->tos-=2;
         return(1);
 err:
         return(0);
         }
 
-#define MONT_WORD
-
-#ifdef MONT_WORD
-int BN_from_montgomery(ret,a,mont,ctx)
-BIGNUM *ret;
-BIGNUM *a;
-BN_MONT_CTX *mont;
-BN_CTX *ctx;
+int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
+             BN_CTX *ctx)
         {
-        BIGNUM *n,*t1,*r;
-        BN_ULONG *ap,*np,*rp,n0,v;
-        int al,nl,max,i,x,ri;
-        int retn=0;
+#ifdef BN_RECURSION_MONT
+        if (mont->use_word)
+#endif
+                {
+                BIGNUM *n,*r;
+                BN_ULONG *ap,*np,*rp,n0,v,*nrp;
+                int al,nl,max,i,x,ri;
+                int retn=0;
 
-        t1=ctx->bn[ctx->tos];
-        r=ctx->bn[ctx->tos+1];
+                r= &(ctx->bn[ctx->tos]);
 
-        if (!BN_copy(r,a)) goto err;
-        n=mont->N;
+                if (!BN_copy(r,a)) goto err1;
+                n= &(mont->N);
 
-        ap=a->d;
-        /* mont->ri is the size of mont->N in bits/words */
-        al=ri=mont->ri/BN_BITS2;
+                ap=a->d;
+                /* mont->ri is the size of mont->N in bits/words */
+                al=ri=mont->ri/BN_BITS2;
 
-        nl=n->top;
-        if ((al == 0) || (nl == 0)) { r->top=0; return(1); }
+                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;
-        if (bn_wexpand(ret,max) == NULL) goto err;
+                max=(nl+al+1); /* allow for overflow (no?) XXX */
+                if (bn_wexpand(r,max) == NULL) goto err1;
+                if (bn_wexpand(ret,max) == NULL) goto err1;
 
-        r->neg=a->neg^n->neg;
-        np=n->d;
-        rp=r->d;
+                r->neg=a->neg^n->neg;
+                np=n->d;
+                rp=r->d;
+                nrp= &(r->d[nl]);
 
-        /* clear the top words of T */
+                /* clear the top words of T */
 #if 1
-        for (i=r->top; i<max; i++) /* memset? XXX */
-                r->d[i]=0;
+                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)); 
+                memset(&(r->d[r->top]),0,(max-r->top)*sizeof(BN_ULONG)); 
 #endif
 
-        r->top=max;
-        n0=mont->n0;
-
-        for (i=0; i<nl; i++)
-                {
-#if 0
-                int x1,x2;
+                r->top=max;
+                n0=mont->n0;
 
-                if (i+4 > nl)
+#ifdef BN_COUNT
+printf("word BN_from_montgomery %d * %d\n",nl,nl);
+#endif
+                for (i=0; i<nl; i++)
                         {
-                        x2=nl;
-                        x1=0;
+                        v=bn_mul_add_words(rp,np,nl,(rp[0]*n0)&BN_MASK2);
+                        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_fix_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;
+                ret->top=al;
+                al-=4;
+                for (i=0; i<al; i+=4)
                         {
-                        x2=i+4;
-                        x1=nl-x2;
+                        BN_ULONG t1,t2,t3,t4;
+
+                        t1=ap[i+0];
+                        t2=ap[i+1];
+                        t3=ap[i+2];
+                        t4=ap[i+3];
+                        rp[i+0]=t1;
+                        rp[i+1]=t2;
+                        rp[i+2]=t3;
+                        rp[i+3]=t4;
                         }
-                v=bn_mul_add_words(&(rp[x1]),&(np[x1]),x2,(rp[x1]*n0)&BN_MASK2);
-#else
-                v=bn_mul_add_words(rp,np,nl,(rp[0]*n0)&BN_MASK2);
+                al+=4;
+                for (; i<al; i++)
+                        rp[i]=ap[i];
 #endif
 
-                if (((rp[nl]+=v)&BN_MASK2) < v)
+                if (BN_ucmp(ret, &(mont->N)) >= 0)
                         {
-                        for (x=(nl+1); (((++rp[x])&BN_MASK2) == 0); x++)
-                                ;
+                        BN_usub(ret,ret,&(mont->N)); /* XXX */
                         }
-                rp++;
+                retn=1;
+err1:
+                return(retn);
                 }
-        while (r->d[r->top-1] == 0)
-                r->top--;
-
-        /* mont->ri will be a multiple of the word size */
-#if 0
-        BN_rshift(ret,r,mont->ri);
-#else
-        ap=r->d;
-        rp=ret->d;
-        x=ri;
-        al=r->top-x;
-        for (i=0; i<al; i++)
+#ifdef BN_RECURSION_MONT
+        else /* bignum version */ 
                 {
-                rp[i]=ap[i+x];
-                }
-        ret->top=al;
+                BIGNUM *t1,*t2,*t3;
+                int j,i;
+
+#ifdef BN_COUNT
+printf("number BN_from_montgomery\n");
 #endif
 
-        if (BN_ucmp(ret,mont->N) >= 0)
-                {
-                bn_qsub(ret,ret,mont->N); /* XXX */
-                }
-        retn=1;
-err:
-        return(retn);
-        }
-#else
-int BN_from_montgomery(r,a,mont,ctx)
-BIGNUM *r;
-BIGNUM *a;
-BN_MONT_CTX *mont;
-BN_CTX *ctx;
-        {
-        BIGNUM *t1,*t2;
+                t1= &(ctx->bn[ctx->tos]);
+                t2= &(ctx->bn[ctx->tos+1]);
+                t3= &(ctx->bn[ctx->tos+2]);
 
-        t1=ctx->bn[ctx->tos];
-        t2=ctx->bn[ctx->tos+1];
+                i=mont->Ni.top;
+                bn_wexpand(ret,i); /* perhaps only i*2 */
+                bn_wexpand(t1,i*4); /* perhaps only i*2 */
+                bn_wexpand(t2,i*2); /* perhaps only i   */
 
-        if (!BN_copy(t1,a)) goto err;
-        /* can cheat */
-        BN_mask_bits(t1,mont->ri);
+                bn_mul_low_recursive(t2->d,a->d,mont->Ni.d,i,t1->d);
 
-        if (!BN_mul(t2,t1,mont->Ni)) goto err;
-        BN_mask_bits(t2,mont->ri);
+                BN_zero(t3);
+                BN_set_bit(t3,mont->N.top*BN_BITS2);
+                bn_sub_words(t3->d,t3->d,a->d,i);
+                bn_mul_high(ret->d,t2->d,mont->N.d,t3->d,i,t1->d);
 
-        if (!BN_mul(t1,t2,mont->N)) goto err;
-        if (!BN_add(t2,a,t1)) goto err;
-        BN_rshift(r,t2,mont->ri);
+                /* hmm... if a is between i and 2*i, things are bad */
+                if (a->top > i)
+                        {
+                        j=(int)(bn_add_words(ret->d,ret->d,&(a->d[i]),i));
+                        if (j) /* overflow */
+                                bn_sub_words(ret->d,ret->d,mont->N.d,i);
+                        }
+                ret->top=i;
+                bn_fix_top(ret);
+                if (a->d[0])
+                        BN_add_word(ret,1); /* Always? */
+                else    /* Very very rare */
+                        {
+                        for (i=1; i<mont->N.top-1; i++)
+                                {
+                                if (a->d[i])
+                                        {
+                                        BN_add_word(ret,1); /* Always? */
+                                        break;
+                                        }
+                                }
+                        }
 
-        if (BN_ucmp(r,mont->N) >= 0)
-                bn_qsub(r,r,mont->N);
+                if (BN_ucmp(ret,&(mont->N)) >= 0)
+                        BN_usub(ret,ret,&(mont->N));
 
-        return(1);
-err:
-        return(0);
-        }
+                return(1);
+                }
 #endif
+        }
 
-BN_MONT_CTX *BN_MONT_CTX_new()
+BN_MONT_CTX *BN_MONT_CTX_new(void)
         {
         BN_MONT_CTX *ret;
 
         if ((ret=(BN_MONT_CTX *)Malloc(sizeof(BN_MONT_CTX))) == NULL)
                 return(NULL);
-        ret->ri=0;
-        ret->RR=BN_new();
-        ret->N=BN_new();
-        ret->Ni=NULL;
-        if ((ret->RR == NULL) || (ret->N == NULL))
-                {
-                BN_MONT_CTX_free(ret);
-                return(NULL);
-                }
+
+        BN_MONT_CTX_init(ret);
+        ret->flags=BN_FLG_MALLOCED;
         return(ret);
         }
 
-void BN_MONT_CTX_free(mont)
-BN_MONT_CTX *mont;
+void BN_MONT_CTX_init(BN_MONT_CTX *ctx)
+        {
+        ctx->use_word=0;
+        ctx->ri=0;
+        BN_init(&(ctx->RR));
+        BN_init(&(ctx->N));
+        BN_init(&(ctx->Ni));
+        ctx->flags=0;
+        }
+
+void BN_MONT_CTX_free(BN_MONT_CTX *mont)
         {
-        if (mont->RR != NULL) BN_free(mont->RR);
-        if (mont->N != NULL) BN_free(mont->N);
-        if (mont->Ni != NULL) BN_free(mont->Ni);
-        Free(mont);
+        if(mont == NULL)
+            return;
+
+        BN_free(&(mont->RR));
+        BN_free(&(mont->N));
+        BN_free(&(mont->Ni));
+        if (mont->flags & BN_FLG_MALLOCED)
+                Free(mont);
         }
 
-int BN_MONT_CTX_set(mont,mod,ctx)
-BN_MONT_CTX *mont;
-BIGNUM *mod;
-BN_CTX *ctx;
+int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
         {
-        BIGNUM *Ri=NULL,*R=NULL;
-
-        if (mont->RR == NULL) mont->RR=BN_new();
-        if (mont->N == NULL)  mont->N=BN_new();
-
-        R=mont->RR;                                     /* grab RR as a temp */
-        BN_copy(mont->N,mod);                           /* Set N */
-
-#ifdef MONT_WORD
-{
-        BIGNUM tmod;
-        BN_ULONG buf[2];
-        /* int z; */
-
-        mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
-        BN_lshift(R,BN_value_one(),BN_BITS2);           /* R */
-        /* I was bad, this modification of a passed variable was
-         * breaking the multithreaded stuff :-(
-         * z=mod->top;
-         * mod->top=1; */
-
-        buf[0]=mod->d[0];
-        buf[1]=0;
-        tmod.d=buf;
-        tmod.top=1;
-        tmod.max=mod->max;
-        tmod.neg=mod->neg;
-
-        if ((Ri=BN_mod_inverse(R,&tmod,ctx)) == NULL) goto err; /* Ri */
-        BN_lshift(Ri,Ri,BN_BITS2);                      /* R*Ri */
-        bn_qsub(Ri,Ri,BN_value_one());                  /* R*Ri - 1 */
-        BN_div(Ri,NULL,Ri,&tmod,ctx);
-        mont->n0=Ri->d[0];
-        BN_free(Ri);
-        /* mod->top=z; */
-}
+        BIGNUM Ri,*R;
+
+        BN_init(&Ri);
+        R= &(mont->RR);                                 /* grab RR as a temp */
+        BN_copy(&(mont->N),mod);                        /* Set N */
+
+#ifdef BN_RECURSION_MONT
+        if (mont->N.top < BN_MONT_CTX_SET_SIZE_WORD)
+#endif
+                {
+                BIGNUM tmod;
+                BN_ULONG buf[2];
+
+                mont->use_word=1;
+
+                mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
+                BN_zero(R);
+                BN_set_bit(R,BN_BITS2);
+                /* I was bad, this modification of a passed variable was
+                 * breaking the multithreaded stuff :-(
+                 * z=mod->top;
+                 * mod->top=1; */
+
+                buf[0]=mod->d[0];
+                buf[1]=0;
+                tmod.d=buf;
+                tmod.top=1;
+                tmod.max=mod->max;
+                tmod.neg=mod->neg;
+
+                if ((BN_mod_inverse(&Ri,R,&tmod,ctx)) == NULL)
+                        goto err;
+                BN_lshift(&Ri,&Ri,BN_BITS2);                    /* R*Ri */
+                if (!BN_is_zero(&Ri))
+                        {
+#if 1
+                        BN_sub_word(&Ri,1);
 #else
-        mont->ri=BN_num_bits(mod);
-        BN_lshift(R,BN_value_one(),mont->ri);                   /* R */
-        if ((Ri=BN_mod_inverse(R,mod,ctx)) == NULL) goto err;   /* Ri */
-        BN_lshift(Ri,Ri,mont->ri);                              /* R*Ri */
-        bn_qsub(Ri,Ri,BN_value_one());                          /* R*Ri - 1 */
-        BN_div(Ri,NULL,Ri,mod,ctx);
-        if (mont->Ni != NULL) BN_free(mont->Ni);
-        mont->Ni=Ri;                                    /* Ni=(R*Ri-1)/N */
+                        BN_usub(&Ri,&Ri,BN_value_one());        /* R*Ri - 1 */
+#endif
+                        }
+                else
+                        {
+                        /* This is not common..., 1 in BN_MASK2,
+                         * It happens when buf[0] was == 1.  So for 8 bit,
+                         * this is 1/256, 16bit, 1 in 2^16 etc.
+                         */
+                        BN_set_word(&Ri,BN_MASK2);
+                        }
+                BN_div(&Ri,NULL,&Ri,&tmod,ctx);
+                mont->n0=Ri.d[0];
+                BN_free(&Ri);
+                /* mod->top=z; */
+                }
+#ifdef BN_RECURSION_MONT
+        else
+                {
+                mont->use_word=0;
+                mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
+#if 1
+                BN_zero(R);
+                BN_set_bit(R,mont->ri);
+#else
+                BN_lshift(R,BN_value_one(),mont->ri);   /* R */
+#endif
+                if ((BN_mod_inverse(&Ri,R,mod,ctx)) == NULL)
+                        goto err;
+                BN_lshift(&Ri,&Ri,mont->ri);            /* R*Ri */
+#if 1
+                BN_sub_word(&Ri,1);
+#else
+                BN_usub(&Ri,&Ri,BN_value_one());        /* R*Ri - 1 */
+#endif
+                BN_div(&(mont->Ni),NULL,&Ri,mod,ctx);
+                BN_free(&Ri);
+                }
 #endif
 
         /* setup RR for conversions */
+#if 1
+        BN_zero(&(mont->RR));
+        BN_set_bit(&(mont->RR),mont->ri*2);
+#else
         BN_lshift(mont->RR,BN_value_one(),mont->ri*2);
-        BN_mod(mont->RR,mont->RR,mont->N,ctx);
+#endif
+        BN_mod(&(mont->RR),&(mont->RR),&(mont->N),ctx);
 
         return(1);
 err:
         return(0);
         }
 
+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));
+        to->use_word=from->use_word;
+        to->ri=from->ri;
+        to->n0=from->n0;
+        return(to);
+        }
+