Correct a typo.

[oweals/openssl.git] / crypto / bn / bn_exp2.c

diff --git a/crypto/bn/bn_exp2.c b/crypto/bn/bn_exp2.c
index 29029f4c724a6c8cfcbef584347ca068ee73d535..73ccd58a83aa1f1c9f4a6bc8313b69ed7d4ebb05 100644 (file)
--- a/crypto/bn/bn_exp2.c
+++ b/crypto/bn/bn_exp2.c
@@ -115,13 +115,14 @@
 
 #define TABLE_SIZE     32
 
-int BN_mod_exp2_mont(BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2,
-            BIGNUM *p2, BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
+int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1,
+       const BIGNUM *a2, const BIGNUM *p2, const BIGNUM *m,
+       BN_CTX *ctx, BN_MONT_CTX *in_mont)
        {
        int i,j,bits,b,bits1,bits2,ret=0,wpos1,wpos2,window1,window2,wvalue1,wvalue2;
        int r_is_one=1,ts1=0,ts2=0;
        BIGNUM *d,*r;
-       BIGNUM *a_mod_m;
+       const BIGNUM *a_mod_m;
        BIGNUM val1[TABLE_SIZE], val2[TABLE_SIZE];
        BN_MONT_CTX *mont=NULL;
 
@@ -140,9 +141,10 @@ int BN_mod_exp2_mont(BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2,
        bits2=BN_num_bits(p2);
        if ((bits1 == 0) && (bits2 == 0))
                {
-               BN_one(rr);
-               return(1);
+               ret = BN_one(rr);
+               return ret;
                }
+       
        bits=(bits1 > bits2)?bits1:bits2;
 
        BN_CTX_start(ctx);
@@ -166,7 +168,7 @@ int BN_mod_exp2_mont(BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2,
         */
        BN_init(&val1[0]);
        ts1=1;
-       if (BN_ucmp(a1,m) >= 0)
+       if (a1->neg || BN_ucmp(a1,m) >= 0)
                {
                if (!BN_mod(&(val1[0]),a1,m,ctx))
                        goto err;
@@ -174,6 +176,12 @@ int BN_mod_exp2_mont(BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2,
                }
        else
                a_mod_m = a1;
+       if (BN_is_zero(a_mod_m))
+               {
+               ret = BN_zero(rr);
+               goto err;
+               }
+
        if (!BN_to_montgomery(&(val1[0]),a_mod_m,mont,ctx)) goto err;
        if (window1 > 1)
                {
@@ -195,7 +203,7 @@ int BN_mod_exp2_mont(BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2,
         */
        BN_init(&val2[0]);
        ts2=1;
-       if (BN_ucmp(a2,m) >= 0)
+       if (a2->neg || BN_ucmp(a2,m) >= 0)
                {
                if (!BN_mod(&(val2[0]),a2,m,ctx))
                        goto err;
@@ -203,6 +211,11 @@ int BN_mod_exp2_mont(BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2,
                }
        else
                a_mod_m = a2;
+       if (BN_is_zero(a_mod_m))
+               {
+               ret = BN_zero(rr);
+               goto err;
+               }
        if (!BN_to_montgomery(&(val2[0]),a_mod_m,mont,ctx)) goto err;
        if (window2 > 1)
                {