Put the first stage of my bignum debugging adventures into CVS. This code

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

diff --git a/crypto/bn/bn_shift.c b/crypto/bn/bn_shift.c
index 944bf1794bc1876de012fc82d82881631011334d..513e686f86a8525ab1e0bbe5b89117f3a9fda500 100644 (file)
--- a/crypto/bn/bn_shift.c
+++ b/crypto/bn/bn_shift.c
@@ -60,9 +60,7 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
-int BN_lshift1(r, a)
-BIGNUM *r;
-BIGNUM *a;
+int BN_lshift1(BIGNUM *r, const BIGNUM *a)
        {
        register BN_ULONG *ap,*rp,t,c;
        int i;
@@ -91,12 +89,11 @@ BIGNUM *a;
                *rp=1;
                r->top++;
                }
+       bn_check_top(r);
        return(1);
        }
 
-int BN_rshift1(r, a)
-BIGNUM *r;
-BIGNUM *a;
+int BN_rshift1(BIGNUM *r, const BIGNUM *a)
        {
        BN_ULONG *ap,*rp,t,c;
        int i;
@@ -121,22 +118,20 @@ BIGNUM *a;
                rp[i]=((t>>1)&BN_MASK2)|c;
                c=(t&1)?BN_TBIT:0;
                }
-       bn_fix_top(r);
+       bn_correct_top(r);
+       bn_check_top(r);
        return(1);
        }
 
-int BN_lshift(r, a, n)
-BIGNUM *r;
-BIGNUM *a;
-int n;
+int BN_lshift(BIGNUM *r, const BIGNUM *a, int n)
        {
        int i,nw,lb,rb;
        BN_ULONG *t,*f;
        BN_ULONG l;
 
        r->neg=a->neg;
-       if (bn_wexpand(r,a->top+(n/BN_BITS2)+1) == NULL) return(0);
        nw=n/BN_BITS2;
+       if (bn_wexpand(r,a->top+nw+1) == NULL) return(0);
        lb=n%BN_BITS2;
        rb=BN_BITS2-lb;
        f=a->d;
@@ -156,14 +151,12 @@ int n;
 /*     for (i=0; i<nw; i++)
                t[i]=0;*/
        r->top=a->top+nw+1;
-       bn_fix_top(r);
+       bn_correct_top(r);
+       bn_check_top(r);
        return(1);
        }
 
-int BN_rshift(r, a, n)
-BIGNUM *r;
-BIGNUM *a;
-int n;
+int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
        {
        int i,j,nw,lb,rb;
        BN_ULONG *t,*f;
@@ -172,7 +165,7 @@ int n;
        nw=n/BN_BITS2;
        rb=n%BN_BITS2;
        lb=BN_BITS2-rb;
-       if (nw > a->top)
+       if (nw > a->top || a->top == 0)
                {
                BN_zero(r);
                return(1);
@@ -182,6 +175,11 @@ int n;
                r->neg=a->neg;
                if (bn_wexpand(r,a->top-nw+1) == NULL) return(0);
                }
+       else
+               {
+               if (n == 0)
+                       return 1; /* or the copying loop will go berserk */
+               }
 
        f= &(a->d[nw]);
        t=r->d;
@@ -205,6 +203,7 @@ int n;
                *(t++) =(l>>rb)&BN_MASK2;
                }
        *t=0;
-       bn_fix_top(r);
+       bn_correct_top(r);
+       bn_check_top(r);
        return(1);
        }