Adjust various bignum functions to use BN_CTX for variables instead of

[openssl.git] / crypto / bn / bn_mont.c

diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c
index 8cf1febaccad8579bcc13d91caf55d520d1c25e1..287392db0f000b8a3aec38f668e8548859071e29 100644 (file)
--- a/crypto/bn/bn_mont.c
+++ b/crypto/bn/bn_mont.c
@@ -69,20 +69,17 @@
 
 #define MONT_WORD /* use the faster word-based algorithm */
 
-int BN_mod_mul_montgomery(BIGNUM *r, BIGNUM *a, BIGNUM *b,
+int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
                          BN_MONT_CTX *mont, BN_CTX *ctx)
        {
-       BIGNUM *tmp,*tmp2;
+       BIGNUM *tmp;
        int ret=0;
 
        BN_CTX_start(ctx);
        tmp = BN_CTX_get(ctx);
-       tmp2 = BN_CTX_get(ctx);
-       if (tmp == NULL || tmp2 == NULL) goto err;
+       if (tmp == NULL) goto err;
 
        bn_check_top(tmp);
-       bn_check_top(tmp2);
-
        if (a == b)
                {
                if (!BN_sqr(tmp,a,ctx)) goto err;
@@ -93,13 +90,14 @@ int BN_mod_mul_montgomery(BIGNUM *r, BIGNUM *a, BIGNUM *b,
                }
        /* reduce from aRR to aR */
        if (!BN_from_montgomery(r,tmp,mont,ctx)) goto err;
+       bn_check_top(r);
        ret=1;
 err:
        BN_CTX_end(ctx);
        return(ret);
        }
 
-int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
+int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
             BN_CTX *ctx)
        {
        int retn=0;
@@ -144,7 +142,7 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
        n0=mont->n0;
 
 #ifdef BN_COUNT
-       printf("word BN_from_montgomery %d * %d\n",nl,nl);
+       fprintf(stderr,"word BN_from_montgomery %d * %d\n",nl,nl);
 #endif
        for (i=0; i<nl; i++)
                {
@@ -175,7 +173,7 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
                        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
@@ -224,14 +222,15 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont,
 
        if (!BN_mul(t1,t2,&mont->N,ctx)) goto err;
        if (!BN_add(t2,a,t1)) goto err;
-       BN_rshift(ret,t2,mont->ri);
+       if (!BN_rshift(ret,t2,mont->ri)) goto err;
 #endif /* MONT_WORD */
 
        if (BN_ucmp(ret, &(mont->N)) >= 0)
                {
-               BN_usub(ret,ret,&(mont->N));
+               if (!BN_usub(ret,ret,&(mont->N))) goto err;
                }
        retn=1;
+       bn_check_top(ret);
  err:
        BN_CTX_end(ctx);
        return(retn);
@@ -272,11 +271,14 @@ void BN_MONT_CTX_free(BN_MONT_CTX *mont)
 
 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 */
+       mont->N.neg = 0;
 
 #ifdef MONT_WORD
                {
@@ -285,60 +287,64 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
 
                mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
                BN_zero(R);
-               BN_set_bit(R,BN_BITS2);                 /* 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=mod->neg;
+               tmod.neg=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;
-               BN_lshift(&Ri,&Ri,BN_BITS2);            /* R*Ri */
-               if (!BN_is_zero(&Ri))
-                       BN_sub_word(&Ri,1);
+               if (!BN_lshift(Ri,Ri,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 */
-                       BN_set_word(&Ri,BN_MASK2);  /* Ri-- (mod word size) */
-               BN_div(&Ri,NULL,&Ri,&tmod,ctx); /* Ni = (R*Ri-1)/N,
-                                                * keep only least significant word: */
-               mont->n0=Ri.d[0];
-               BN_free(&Ri);
+                       {
+                       if (!BN_set_word(Ri,BN_MASK2)) goto err;  /* Ri-- (mod word size) */
+                       }
+               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;
                }
 #else /* !MONT_WORD */
                { /* bignum version */
-               mont->ri=BN_num_bits(mod);
+               mont->ri=BN_num_bits(&mont->N);
                BN_zero(R);
-               BN_set_bit(R,mont->ri);                 /* R = 2^ri */
-                                                       /* Ri = R^-1 mod N*/
-               if ((BN_mod_inverse(&Ri,R,mod,ctx)) == NULL)
+               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)
                        goto err;
-               BN_lshift(&Ri,&Ri,mont->ri);            /* R*Ri */
-               BN_sub_word(&Ri,1);
+               if (!BN_lshift(Ri,Ri,mont->ri)) goto err; /* R*Ri */
+               if (!BN_sub_word(Ri,1)) goto err;
                                                        /* Ni = (R*Ri-1) / N */
-               BN_div(&(mont->Ni),NULL,&Ri,mod,ctx);
-               BN_free(&Ri);
+               if (!BN_div(&(mont->Ni),NULL,Ri,&mont->N,ctx)) goto err;
                }
 #endif
 
        /* setup RR for conversions */
        BN_zero(&(mont->RR));
-       BN_set_bit(&(mont->RR),mont->ri*2);
-       BN_mod(&(mont->RR),&(mont->RR),&(mont->N),ctx);
+       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 (to == from) return(to);
 
-       BN_copy(&(to->RR),&(from->RR));
-       BN_copy(&(to->N),&(from->N));
-       BN_copy(&(to->Ni),&(from->Ni));
+       if (!BN_copy(&(to->RR),&(from->RR))) return NULL;
+       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;
        return(to);