1 files changed, 23 insertions, 43 deletions

diff --git a/src/lib/libcrypto/bn/bn_div.c b/src/lib/libcrypto/bn/bn_div.c
index c328b5b411..ac1a09615a 100644
--- a/src/lib/libcrypto/bn/bn_div.c
+++ b/src/lib/libcrypto/bn/bn_div.c
@@ -61,6 +61,7 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
+
 /* The old slow way */
 #if 0
 int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
@@ -126,9 +127,10 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
 
 #else
 
-#if !defined(NO_ASM) && !defined(NO_INLINE_ASM) && !defined(PEDANTIC) && !defined(BN_DIV3W)
+#if !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM) \
+    && !defined(PEDANTIC) && !defined(BN_DIV3W)
 # if defined(__GNUC__) && __GNUC__>=2
-#  if defined(__i386)
+#  if defined(__i386) || defined (__i386__)
    /*
     * There were two reasons for implementing this template:
     * - GNU C generates a call to a function (__udivdi3 to be exact)
@@ -150,8 +152,16 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
 #  define REMAINDER_IS_ALREADY_CALCULATED
 #  endif /* __<cpu> */
 # endif /* __GNUC__ */
-#endif /* NO_ASM */
+#endif /* OPENSSL_NO_ASM */
+
 
+/* BN_div 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.
+ */
 int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
            BN_CTX *ctx)
         {
@@ -185,7 +195,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
         if (dv == NULL)
                 res=BN_CTX_get(ctx);
         else    res=dv;
-        if (sdiv==NULL || res == NULL) goto err;
+        if (sdiv == NULL || res == NULL) goto err;
         tmp->neg=0;
 
         /* First we normalise the numbers */
@@ -232,12 +242,14 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
                 }
         else
                 res->top--;
+        if (res->top == 0)
+                res->neg = 0;
         resp--;
 
         for (i=0; i<loop-1; i++)
                 {
                 BN_ULONG q,l0;
-#if defined(BN_DIV3W) && !defined(NO_ASM)
+#if defined(BN_DIV3W) && !defined(OPENSSL_NO_ASM)
                 BN_ULONG bn_div_3_words(BN_ULONG*,BN_ULONG,BN_ULONG);
                 q=bn_div_3_words(wnump,d1,d0);
 #else
@@ -331,8 +343,13 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
                 }
         if (rm != NULL)
                 {
+                /* Keep a copy of the neg flag in num because if rm==num
+                 * BN_rshift() will overwrite it.
+                 */
+                int neg = num->neg;
                 BN_rshift(rm,snum,norm_shift);
-                rm->neg=num->neg;
+                if (!BN_is_zero(rm))
+                        rm->neg = neg;
                 }
         BN_CTX_end(ctx);
         return(1);
@@ -342,40 +359,3 @@ err:
         }
 
 #endif
-
-/* rem != m */
-int BN_mod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
-        {
-#if 0 /* The old slow way */
-        int i,nm,nd;
-        BIGNUM *dv;
-
-        if (BN_ucmp(m,d) < 0)
-                return((BN_copy(rem,m) == NULL)?0:1);
-
-        BN_CTX_start(ctx);
-        dv=BN_CTX_get(ctx);
-
-        if (!BN_copy(rem,m)) goto err;
-
-        nm=BN_num_bits(rem);
-        nd=BN_num_bits(d);
-        if (!BN_lshift(dv,d,nm-nd)) goto err;
-        for (i=nm-nd; i>=0; i--)
-                {
-                if (BN_cmp(rem,dv) >= 0)
-                        {
-                        if (!BN_sub(rem,rem,dv)) goto err;
-                        }
-                if (!BN_rshift1(dv,dv)) goto err;
-                }
-        BN_CTX_end(ctx);
-        return(1);
- err:
-        BN_CTX_end(ctx);
-        return(0);
-#else
-        return(BN_div(NULL,rem,m,d,ctx));
-#endif
-        }
-