Botan  2.6.0
Crypto and TLS for C++11
code_based_util.h
Go to the documentation of this file.
1 /*
2  * (C) Copyright Projet SECRET, INRIA, Rocquencourt
3  * (C) Bhaskar Biswas and Nicolas Sendrier
4  *
5  * (C) 2014 cryptosource GmbH
6  * (C) 2014 Falko Strenzke fstrenzke@cryptosource.de
7  *
8  * Botan is released under the Simplified BSD License (see license.txt)
9  *
10  */
11 
12 #ifndef BOTAN_CODE_BASED_UTIL_H_
13 #define BOTAN_CODE_BASED_UTIL_H_
14 
15 #include <botan/gf2m_small_m.h>
16 
17 namespace Botan {
18 
19 /**
20 * Expand an input to a bit mask depending on it being being zero or non-zero
21 * @param tst the input
22 * @return the mask 0xFFFF if tst is non-zero and 0 otherwise
23 */
24 template<typename T>
25 uint16_t expand_mask_16bit(T tst)
26  {
27  const uint16_t result = (tst != 0);
28  return ~(result - 1);
29  }
30 
31 inline gf2m gray_to_lex(gf2m gray)
32  {
33  gf2m result = gray ^ (gray >> 8);
34  result ^= (result >> 4);
35  result ^= (result >> 2);
36  result ^= (result >> 1);
37  return result;
38  }
39 
40 inline gf2m lex_to_gray(gf2m lex)
41  {
42  return (lex >> 1) ^ lex;
43  }
44 
45 inline uint32_t bit_size_to_byte_size(uint32_t bit_size)
46  {
47  return (bit_size - 1) / 8 + 1;
48  }
49 
50 inline uint32_t bit_size_to_32bit_size(uint32_t bit_size)
51  {
52  return (bit_size - 1) / 32 + 1;
53  }
54 
55 }
56 
57 #endif
uint32_t bit_size_to_32bit_size(uint32_t bit_size)
uint32_t bit_size_to_byte_size(uint32_t bit_size)
gf2m gray_to_lex(gf2m gray)
gf2m lex_to_gray(gf2m lex)
uint16_t expand_mask_16bit(T tst)
uint16_t gf2m
Definition: gf2m_small_m.h:20
Definition: alg_id.cpp:13
fe T
Definition: ge.cpp:37