1 files changed, 52 insertions, 19 deletions
diff --git a/app/openssl/crypto/bn/bn_lib.c b/app/openssl/crypto/bn/bn_lib.c
index 5470fbe6..5461e6ee 100644
--- a/app/openssl/crypto/bn/bn_lib.c
+++ b/app/openssl/crypto/bn/bn_lib.c
@@ -139,25 +139,6 @@ const BIGNUM *BN_value_one(void)
 	return(&const_one);
 	}
 
-char *BN_options(void)
-	{
-	static int init=0;
-	static char data[16];
-
-	if (!init)
-		{
-		init++;
-#ifdef BN_LLONG
-		BIO_snprintf(data,sizeof data,"bn(%d,%d)",
-			     (int)sizeof(BN_ULLONG)*8,(int)sizeof(BN_ULONG)*8);
-#else
-		BIO_snprintf(data,sizeof data,"bn(%d,%d)",
-			     (int)sizeof(BN_ULONG)*8,(int)sizeof(BN_ULONG)*8);
-#endif
-		}
-	return(data);
-	}
-
 int BN_num_bits_word(BN_ULONG l)
 	{
 	static const unsigned char bits[256]={
@@ -843,3 +824,55 @@ int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b,
 		}
 	return bn_cmp_words(a,b,cl);
 	}
+
+/* 
+ * Constant-time conditional swap of a and b.  
+ * a and b are swapped if condition is not 0.  The code assumes that at most one bit of condition is set.
+ * nwords is the number of words to swap.  The code assumes that at least nwords are allocated in both a and b,
+ * and that no more than nwords are used by either a or b.
+ * a and b cannot be the same number
+ */
+void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords)
+	{
+	BN_ULONG t;
+	int i;
+
+	bn_wcheck_size(a, nwords);
+	bn_wcheck_size(b, nwords);
+
+	assert(a != b);
+	assert((condition & (condition - 1)) == 0);
+	assert(sizeof(BN_ULONG) >= sizeof(int));
+
+	condition = ((condition - 1) >> (BN_BITS2 - 1)) - 1;
+
+	t = (a->top^b->top) & condition;
+	a->top ^= t;
+	b->top ^= t;
+
+#define BN_CONSTTIME_SWAP(ind) \
+	do { \
+		t = (a->d[ind] ^ b->d[ind]) & condition; \
+		a->d[ind] ^= t; \
+		b->d[ind] ^= t; \
+	} while (0)
+
+
+	switch (nwords) {
+	default:
+		for (i = 10; i < nwords; i++) 
+			BN_CONSTTIME_SWAP(i);
+		/* Fallthrough */
+	case 10: BN_CONSTTIME_SWAP(9); /* Fallthrough */
+	case 9: BN_CONSTTIME_SWAP(8); /* Fallthrough */
+	case 8: BN_CONSTTIME_SWAP(7); /* Fallthrough */
+	case 7: BN_CONSTTIME_SWAP(6); /* Fallthrough */
+	case 6: BN_CONSTTIME_SWAP(5); /* Fallthrough */
+	case 5: BN_CONSTTIME_SWAP(4); /* Fallthrough */
+	case 4: BN_CONSTTIME_SWAP(3); /* Fallthrough */
+	case 3: BN_CONSTTIME_SWAP(2); /* Fallthrough */
+	case 2: BN_CONSTTIME_SWAP(1); /* Fallthrough */
+	case 1: BN_CONSTTIME_SWAP(0);
+	}
+#undef BN_CONSTTIME_SWAP
+}