X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fconstant_time_locl.h;h=6410ca789b07494c1aa3172be4e5e4cd7f7fc1a4;hb=2a3e745a1760e34a86fe36faee613542939b7004;hp=c0483939fe3dbb2fa137f9f0feb594b587673e9f;hpb=699d78ce985f718ece999025c7c582acc7aa3aaf;p=oweals%2Fopenssl.git

diff --git a/crypto/constant_time_locl.h b/crypto/constant_time_locl.h
index c0483939fe..6410ca789b 100644
--- a/crypto/constant_time_locl.h
+++ b/crypto/constant_time_locl.h
@@ -1,5 +1,5 @@
 /* crypto/constant_time_locl.h */
-/*
+/*-
  * Utilities for constant-time cryptography.
  *
  * Author: Emilia Kasper (emilia@openssl.org)
@@ -53,7 +53,7 @@
 extern "C" {
 #endif
 
-/*
+/*-
  * The boolean methods return a bitmask of all ones (0xff...f) for true
  * and 0 for false. This is useful for choosing a value based on the result
  * of a conditional in constant time. For example,
@@ -112,7 +112,7 @@ static inline unsigned int constant_time_eq_int(int a, int b);
 static inline unsigned char constant_time_eq_int_8(int a, int b);
 
 
-/*
+/*-
  * Returns (mask & a) | (~mask & b).
  *
  * When |mask| is all 1s or all 0s (as returned by the methods above),
@@ -129,17 +129,12 @@ static inline int constant_time_select_int(unsigned int mask, int a, int b);
 
 static inline unsigned int constant_time_msb(unsigned int a)
 	{
-	return (unsigned int)((int)(a) >> (sizeof(int) * 8 - 1));
+	return 0-(a >> (sizeof(a) * 8 - 1));
 	}
 
 static inline unsigned int constant_time_lt(unsigned int a, unsigned int b)
 	{
-	unsigned int lt;
-	/* Case 1: msb(a) == msb(b). a < b iff the MSB of a - b is set.*/
-	lt = ~(a ^ b) & (a - b);
-	/* Case 2: msb(a) != msb(b). a < b iff the MSB of b is set. */
-	lt |= ~a & b;
-	return constant_time_msb(lt);
+	return constant_time_msb(a^((a^b)|((a-b)^b)));
 	}
 
 static inline unsigned char constant_time_lt_8(unsigned int a, unsigned int b)
@@ -149,12 +144,7 @@ static inline unsigned char constant_time_lt_8(unsigned int a, unsigned int b)
 
 static inline unsigned int constant_time_ge(unsigned int a, unsigned int b)
 	{
-	unsigned int ge;
-	/* Case 1: msb(a) == msb(b). a >= b iff the MSB of a - b is not set.*/
-	ge = ~((a ^ b) | (a - b));
-	/* Case 2: msb(a) != msb(b). a >= b iff the MSB of a is set. */
-	ge |= a & ~b;
-	return constant_time_msb(ge);
+	return ~constant_time_lt(a, b);
 	}
 
 static inline unsigned char constant_time_ge_8(unsigned int a, unsigned int b)
@@ -204,7 +194,7 @@ static inline unsigned char constant_time_select_8(unsigned char mask,
 	return (unsigned char)(constant_time_select(mask, a, b));
 	}
 
-inline int constant_time_select_int(unsigned int mask, int a, int b)
+static inline int constant_time_select_int(unsigned int mask, int a, int b)
 	{
 	return (int)(constant_time_select(mask, (unsigned)(a), (unsigned)(b)));
 	}