+/* BN_mod_exp_mont_conttime is based on the assumption that the
+ * L1 data cache line width of the target processor is at least
+ * the following value.
+ */
+#define MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH ( 64 )
+#define MOD_EXP_CTIME_MIN_CACHE_LINE_MASK (MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - 1)
+
+/* Window sizes optimized for fixed window size modular exponentiation
+ * algorithm (BN_mod_exp_mont_consttime).
+ *
+ * To achieve the security goals of BN_mode_exp_mont_consttime, the
+ * maximum size of the window must not exceed
+ * log_2(MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH).
+ *
+ * Window size thresholds are defined for cache line sizes of 32 and 64,
+ * cache line sizes where log_2(32)=5 and log_2(64)=6 respectively. A
+ * window size of 7 should only be used on processors that have a 128
+ * byte or greater cache line size.
+ */
+#if MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 64
+
+# define BN_window_bits_for_ctime_exponent_size(b) \
+ ((b) > 937 ? 6 : \
+ (b) > 306 ? 5 : \
+ (b) > 89 ? 4 : \
+ (b) > 22 ? 3 : 1)
+# define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE (6)
+
+#elif MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 32
+
+# define BN_window_bits_for_ctime_exponent_size(b) \
+ ((b) > 306 ? 5 : \
+ (b) > 89 ? 4 : \
+ (b) > 22 ? 3 : 1)
+# define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE (5)
+
+#endif
+
+
/* Pentium pro 16,16,16,32,64 */
/* Alpha 16,16,16,16.64 */
#define BN_MULL_SIZE_NORMAL (16) /* 32 */
#define Lw(t) (((BN_ULONG)(t))&BN_MASK2)
#define Hw(t) (((BN_ULONG)((t)>>BN_BITS2))&BN_MASK2)
-
+#ifdef BN_DEBUG_RAND
#define bn_clear_top2max(a) \
{ \
int ind = (a)->dmax - (a)->top; \
for (; ind != 0; ind--) \
*(++ftl) = 0x0; \
}
-
-
-/* This is used for internal error checking and is not normally used */
-#ifdef BN_DEBUG
-# include <assert.h>
-# define bn_check_top(a) assert ((a)->top >= 0 && (a)->top <= (a)->dmax);
-#else
-# define bn_check_top(a)
-#endif
-
-/* This macro is to add extra stuff for development checking */
-#ifdef BN_DEBUG
-#define bn_set_max(r) ((r)->max=(r)->top,BN_set_flags((r),BN_FLG_STATIC_DATA))
#else
-#define bn_set_max(r)
+#define bn_clear_top2max(a)
#endif
-/* These macros are used to 'take' a section of a bignum for read only use */
-#define bn_set_low(r,a,n) \
- { \
- (r)->top=((a)->top > (n))?(n):(a)->top; \
- (r)->d=(a)->d; \
- (r)->neg=(a)->neg; \
- (r)->flags|=BN_FLG_STATIC_DATA; \
- bn_set_max(r); \
- }
-
-#define bn_set_high(r,a,n) \
- { \
- if ((a)->top > (n)) \
- { \
- (r)->top=(a)->top-n; \
- (r)->d= &((a)->d[n]); \
- } \
- else \
- (r)->top=0; \
- (r)->neg=(a)->neg; \
- (r)->flags|=BN_FLG_STATIC_DATA; \
- bn_set_max(r); \
- }
-
#ifdef BN_LLONG
#define mul_add(r,a,w,c) { \
BN_ULLONG t; \