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comparison libtomcrypt/src/modes/xts/xts_mult_x.c @ 1511:5916af64acd4 fuzz

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merge from main
author Matt Johnston <matt@ucc.asn.au>
date Sat, 17 Feb 2018 19:29:51 +0800
parents 6dba84798cd5
children
comparison
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1457:32f990cc96b1 1511:5916af64acd4
3 * LibTomCrypt is a library that provides various cryptographic 3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner. 4 * algorithms in a highly modular and flexible manner.
5 * 5 *
6 * The library is free for all purposes without any express 6 * The library is free for all purposes without any express
7 * guarantee it works. 7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtom.org
10 */ 8 */
11 #include "tomcrypt.h" 9 #include "tomcrypt.h"
12 10
13 /** 11 /**
14 Source donated by Elliptic Semiconductor Inc (www.ellipticsemi.com) to the LibTom Projects 12 Source donated by Elliptic Semiconductor Inc (www.ellipticsemi.com) to the LibTom Projects
15 */ 13 */
16 14
17 #ifdef LTC_XTS_MODE 15 #ifdef LTC_XTS_MODE
18 16
19 /** multiply by x 17 /** multiply by x
20 @param I The value to multiply by x (LFSR shift) 18 @param I The value to multiply by x (LFSR shift)
21 */ 19 */
22 void xts_mult_x(unsigned char *I) 20 void xts_mult_x(unsigned char *I)
23 { 21 {
24 int x; 22 int x;
25 unsigned char t, tt; 23 unsigned char t, tt;
26 24
27 for (x = t = 0; x < 16; x++) { 25 for (x = t = 0; x < 16; x++) {
28 tt = I[x] >> 7; 26 tt = I[x] >> 7;
29 I[x] = ((I[x] << 1) | t) & 0xFF; 27 I[x] = ((I[x] << 1) | t) & 0xFF;
30 t = tt; 28 t = tt;
31 } 29 }
32 if (tt) { 30 if (tt) {
33 I[0] ^= 0x87; 31 I[0] ^= 0x87;
34 } 32 }
35 } 33 }
36 34
37 #endif 35 #endif
38 36
39 /* $Source$ */ 37 /* ref: $Format:%D$ */
40 /* $Revision$ */ 38 /* git commit: $Format:%H$ */
41 /* $Date$ */ 39 /* commit time: $Format:%ai$ */
42