random.c patch

From: Karel Kulhavy (clock@atrey.karlin.mff.cuni.cz)
Date: Sun Dec 17 2000 - 16:44:52 EST


There are several places where the rotation yields garbage according to ANSI
C definition when called with 0 bit position argument.

diff -Pur linux_reference/drivers/char/random.c linux/drivers/char/random.c
--- linux_reference/drivers/char/random.c Wed Jul 19 00:58:13 2000
+++ linux/drivers/char/random.c Sun Dec 17 22:42:59 2000
@@ -411,7 +411,7 @@
 #if (!defined (__i386__))
 extern inline __u32 rotate_left(int i, __u32 word)
 {
- return (word << i) | (word >> (32 - i));
+ return (word << i) | (word >> ((-i)&31));
         
 }
 #else
@@ -857,7 +857,7 @@
 #define K3 0x8F1BBCDCL /* Rounds 40-59: sqrt(5) * 2^30 */
 #define K4 0xCA62C1D6L /* Rounds 60-79: sqrt(10) * 2^30 */
 
-#define ROTL(n,X) ( ( ( X ) << n ) | ( ( X ) >> ( 32 - n ) ) )
+#define ROTL(n,X) ( ( ( X ) << n ) | ( ( X ) >> ( (- n)&31 ) ) )
 
 #define subRound(a, b, c, d, e, f, k, data) \
     ( e += ROTL( 5, a ) + f( b, c, d ) + k + data, b = ROTL( 30, b ) )
@@ -1087,7 +1087,7 @@
 
 /* This is the central step in the MD5 algorithm. */
 #define MD5STEP(f, w, x, y, z, data, s) \
- ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
+ ( w += f(x, y, z) + data, w = w<<s | w>>((-s)&31), w += x )
 
 /*
  * The core of the MD5 algorithm, this alters an existing MD5 hash to
@@ -1883,7 +1883,7 @@
  * Rotation is separate from addition to prevent recomputation
  */
 #define ROUND(f, a, b, c, d, x, s) \
- (a += f(b, c, d) + x, a = (a << s) | (a >> (32-s)))
+ (a += f(b, c, d) + x, a = (a << s) | (a >> ((-s)&31)))
 #define K1 0
 #define K2 013240474631UL
 #define K3 015666365641UL

 Clock

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