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annotate libtomcrypt/src/encauth/ocb3/ocb3_int_ntz.c @ 1471:6dba84798cd5

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Update to libtomcrypt 1.18.1, merged with Dropbear changes
author Matt Johnston <matt@ucc.asn.au>
date Fri, 09 Feb 2018 21:44:05 +0800
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1471
6dba84798cd5 Update to libtomcrypt 1.18.1, merged with Dropbear changes
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1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
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2 *
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3 * LibTomCrypt is a library that provides various cryptographic
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4 * algorithms in a highly modular and flexible manner.
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5 *
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6 * The library is free for all purposes without any express
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7 * guarantee it works.
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8 */
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9
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10 /**
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11 @file ocb3_int_ntz.c
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12 OCB implementation, INTERNAL ONLY helper, by Tom St Denis
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13 */
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14 #include "tomcrypt.h"
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15
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16 #ifdef LTC_OCB3_MODE
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17
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18 /**
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19 Returns the number of leading zero bits [from lsb up] (internal function)
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20 @param x The 32-bit value to observe
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21 @return The number of bits [from the lsb up] that are zero
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22 */
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23 int ocb3_int_ntz(unsigned long x)
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24 {
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25 int c;
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26 x &= 0xFFFFFFFFUL;
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27 c = 0;
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28 while ((x & 1) == 0) {
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29 ++c;
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30 x >>= 1;
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31 }
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32 return c;
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33 }
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34
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35 #endif
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36
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37 /* ref: $Format:%D$ */
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38 /* git commit: $Format:%H$ */
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39 /* commit time: $Format:%ai$ */