sha512-x86_64.pl: fix typo.

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

diff --git a/crypto/bn/bn_sqr.c b/crypto/bn/bn_sqr.c
index b75e6194d029566584aa03f121023f265727da24..270d0cd348b90056f14ce429676b700cd577118b 100644 (file)
--- a/crypto/bn/bn_sqr.c
+++ b/crypto/bn/bn_sqr.c
@@ -77,16 +77,16 @@ int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
        if (al <= 0)
                {
                r->top=0;
-               return(1);
+               return 1;
                }
 
        BN_CTX_start(ctx);
        rr=(a != r) ? r : BN_CTX_get(ctx);
        tmp=BN_CTX_get(ctx);
-       if (tmp == NULL) goto err;
+       if (!rr || !tmp) goto err;
 
-       max=(al+al);
-       if (bn_wexpand(rr,max+1) == NULL) goto err;
+       max = 2 * al; /* Non-zero (from above) */
+       if (bn_wexpand(rr,max) == NULL) goto err;
 
        if (al == 4)
                {
@@ -138,12 +138,18 @@ int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
 #endif
                }
 
-       rr->top=max;
        rr->neg=0;
-       if ((max > 0) && (rr->d[max-1] == 0)) rr->top--;
+       /* If the most-significant half of the top word of 'a' is zero, then
+        * the square of 'a' will max-1 words. */
+       if(a->d[al - 1] == (a->d[al - 1] & BN_MASK2l))
+               rr->top = max - 1;
+       else
+               rr->top = max;
        if (rr != r) BN_copy(r,rr);
        ret = 1;
  err:
+       bn_check_top(rr);
+       bn_check_top(tmp);
        BN_CTX_end(ctx);
        return(ret);
        }
@@ -245,7 +251,7 @@ void bn_sqr_recursive(BN_ULONG *r, const BN_ULONG *a, int n2, BN_ULONG *t)
        if (!zero)
                bn_sqr_recursive(&(t[n2]),t,n,p);
        else
-               memset(&(t[n2]),0,n*sizeof(BN_ULONG));
+               memset(&(t[n2]),0,n2*sizeof(BN_ULONG));
        bn_sqr_recursive(r,a,n,p);
        bn_sqr_recursive(&(r[n2]),&(a[n]),n,p);