* [including the GNU Public Licence.]
*/
+#define OPENSSL_FIPSAPI
+
#include <stdio.h>
#include <openssl/bn.h>
#include "cryptlib.h"
/* The next 2 are needed so we can do a dv->d[0]|=1 later
* since BN_lshift1 will only work once there is a value :-) */
BN_zero(dv);
- bn_wexpand(dv,1);
+ if(bn_wexpand(dv,1) == NULL) goto end;
dv->top=1;
if (!BN_lshift(D,D,nm-nd)) goto end;
* Same story here, but it's 128-bit by 64-bit division. Wow!
* <appro@fy.chalmers.se>
*/
+# undef bn_div_words
# define bn_div_words(n0,n1,d0) \
({ asm volatile ( \
"divq %4" \
#endif /* OPENSSL_NO_ASM */
-/* BN_div computes dv := num / divisor, rounding towards zero, and sets up
- * rm such that dv*divisor + rm = num holds.
+/* BN_div[_no_branch] computes dv := num / divisor, rounding towards
+ * zero, and sets up rm such that dv*divisor + rm = num holds.
* Thus:
* dv->neg == num->neg ^ divisor->neg (unless the result is zero)
* rm->neg == num->neg (unless the remainder is zero)
* If 'dv' or 'rm' is NULL, the respective value is not returned.
*/
+static int BN_div_no_branch(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num,
+ const BIGNUM *divisor, BN_CTX *ctx);
int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
BN_CTX *ctx)
{
BN_ULONG d0,d1;
int num_n,div_n;
- if (BN_get_flags(num, BN_FLG_CONSTTIME) != 0)
+ /* Invalid zero-padding would have particularly bad consequences
+ * in the case of 'num', so don't just rely on bn_check_top() for this one
+ * (bn_check_top() works only for BN_DEBUG builds) */
+ if (num->top > 0 && num->d[num->top - 1] == 0)
+ {
+ BNerr(BN_F_BN_DIV,BN_R_NOT_INITIALIZED);
+ return 0;
+ }
+
+ bn_check_top(num);
+
+ if ((BN_get_flags(num, BN_FLG_CONSTTIME) != 0) || (BN_get_flags(divisor, BN_FLG_CONSTTIME) != 0))
{
return BN_div_no_branch(dv, rm, num, divisor, ctx);
}
bn_check_top(dv);
bn_check_top(rm);
- bn_check_top(num);
+ /* bn_check_top(num); */ /* 'num' has been checked already */
bn_check_top(divisor);
if (BN_is_zero(divisor))
if (dv == NULL)
res=BN_CTX_get(ctx);
else res=dv;
- if (sdiv == NULL || res == NULL) goto err;
+ if (sdiv == NULL || res == NULL || tmp == NULL || snum == NULL)
+ goto err;
/* First we normalise the numbers */
norm_shift=BN_BITS2-((BN_num_bits(divisor))%BN_BITS2);
t2 -= d1;
}
#else /* !BN_LLONG */
- BN_ULONG t2l,t2h,ql,qh;
+ BN_ULONG t2l,t2h;
q=bn_div_words(n0,n1,d0);
#ifdef BN_DEBUG_LEVITTE
t2l = d1 * q;
t2h = BN_UMULT_HIGH(d1,q);
#else
+ {
+ BN_ULONG ql, qh;
t2l=LBITS(d1); t2h=HBITS(d1);
ql =LBITS(q); qh =HBITS(q);
mul64(t2l,t2h,ql,qh); /* t2=(BN_ULLONG)d1*q; */
+ }
#endif
for (;;)
/* BN_div_no_branch is a special version of BN_div. It does not contain
* branches that may leak sensitive information.
*/
-int BN_div_no_branch(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num,
+static int BN_div_no_branch(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num,
const BIGNUM *divisor, BN_CTX *ctx)
{
int norm_shift,i,loop;
bn_check_top(dv);
bn_check_top(rm);
- bn_check_top(num);
+ /* bn_check_top(num); */ /* 'num' has been checked in BN_div() */
bn_check_top(divisor);
if (BN_is_zero(divisor))
{
- BNerr(BN_F_BN_DIV,BN_R_DIV_BY_ZERO);
+ BNerr(BN_F_BN_DIV_NO_BRANCH,BN_R_DIV_BY_ZERO);
return(0);
}
t2 -= d1;
}
#else /* !BN_LLONG */
- BN_ULONG t2l,t2h,ql,qh;
+ BN_ULONG t2l,t2h;
q=bn_div_words(n0,n1,d0);
#ifdef BN_DEBUG_LEVITTE
t2l = d1 * q;
t2h = BN_UMULT_HIGH(d1,q);
#else
+ {
+ BN_ULONG ql, qh;
t2l=LBITS(d1); t2h=HBITS(d1);
ql =LBITS(q); qh =HBITS(q);
mul64(t2l,t2h,ql,qh); /* t2=(BN_ULLONG)d1*q; */
+ }
#endif
for (;;)
rm->neg = neg;
bn_check_top(rm);
}
+ bn_correct_top(res);
BN_CTX_end(ctx);
return(1);
err: