Crypto++ 8.7
Free C++ class library of cryptographic schemes
safer.cpp
1// safer.cpp - modified by by Wei Dai from Richard De Moliner's safer.c
2
3#include "pch.h"
4#include "safer.h"
5#include "misc.h"
6#include "argnames.h"
7
8#if CRYPTOPP_MSC_VERSION
9# pragma warning(disable: 4244)
10#endif
11
12NAMESPACE_BEGIN(CryptoPP)
13
14const byte SAFER::Base::exp_tab[256] =
15 {1, 45, 226, 147, 190, 69, 21, 174, 120, 3, 135, 164, 184, 56, 207, 63,
16 8, 103, 9, 148, 235, 38, 168, 107, 189, 24, 52, 27, 187, 191, 114, 247,
17 64, 53, 72, 156, 81, 47, 59, 85, 227, 192, 159, 216, 211, 243, 141, 177,
18 255, 167, 62, 220, 134, 119, 215, 166, 17, 251, 244, 186, 146, 145, 100, 131,
19 241, 51, 239, 218, 44, 181, 178, 43, 136, 209, 153, 203, 140, 132, 29, 20,
20 129, 151, 113, 202, 95, 163, 139, 87, 60, 130, 196, 82, 92, 28, 232, 160,
21 4, 180, 133, 74, 246, 19, 84, 182, 223, 12, 26, 142, 222, 224, 57, 252,
22 32, 155, 36, 78, 169, 152, 158, 171, 242, 96, 208, 108, 234, 250, 199, 217,
23 0, 212, 31, 110, 67, 188, 236, 83, 137, 254, 122, 93, 73, 201, 50, 194,
24 249, 154, 248, 109, 22, 219, 89, 150, 68, 233, 205, 230, 70, 66, 143, 10,
25 193, 204, 185, 101, 176, 210, 198, 172, 30, 65, 98, 41, 46, 14, 116, 80,
26 2, 90, 195, 37, 123, 138, 42, 91, 240, 6, 13, 71, 111, 112, 157, 126,
27 16, 206, 18, 39, 213, 76, 79, 214, 121, 48, 104, 54, 117, 125, 228, 237,
28 128, 106, 144, 55, 162, 94, 118, 170, 197, 127, 61, 175, 165, 229, 25, 97,
29 253, 77, 124, 183, 11, 238, 173, 75, 34, 245, 231, 115, 35, 33, 200, 5,
30 225, 102, 221, 179, 88, 105, 99, 86, 15, 161, 49, 149, 23, 7, 58, 40};
31
32const byte SAFER::Base::log_tab[256] =
33 {128, 0, 176, 9, 96, 239, 185, 253, 16, 18, 159, 228, 105, 186, 173, 248,
34 192, 56, 194, 101, 79, 6, 148, 252, 25, 222, 106, 27, 93, 78, 168, 130,
35 112, 237, 232, 236, 114, 179, 21, 195, 255, 171, 182, 71, 68, 1, 172, 37,
36 201, 250, 142, 65, 26, 33, 203, 211, 13, 110, 254, 38, 88, 218, 50, 15,
37 32, 169, 157, 132, 152, 5, 156, 187, 34, 140, 99, 231, 197, 225, 115, 198,
38 175, 36, 91, 135, 102, 39, 247, 87, 244, 150, 177, 183, 92, 139, 213, 84,
39 121, 223, 170, 246, 62, 163, 241, 17, 202, 245, 209, 23, 123, 147, 131, 188,
40 189, 82, 30, 235, 174, 204, 214, 53, 8, 200, 138, 180, 226, 205, 191, 217,
41 208, 80, 89, 63, 77, 98, 52, 10, 72, 136, 181, 86, 76, 46, 107, 158,
42 210, 61, 60, 3, 19, 251, 151, 81, 117, 74, 145, 113, 35, 190, 118, 42,
43 95, 249, 212, 85, 11, 220, 55, 49, 22, 116, 215, 119, 167, 230, 7, 219,
44 164, 47, 70, 243, 97, 69, 103, 227, 12, 162, 59, 28, 133, 24, 4, 29,
45 41, 160, 143, 178, 90, 216, 166, 126, 238, 141, 83, 75, 161, 154, 193, 14,
46 122, 73, 165, 44, 129, 196, 199, 54, 43, 127, 67, 149, 51, 242, 108, 104,
47 109, 240, 2, 40, 206, 221, 155, 234, 94, 153, 124, 20, 134, 207, 229, 66,
48 184, 64, 120, 45, 58, 233, 100, 31, 146, 144, 125, 57, 111, 224, 137, 48};
49
50#define EXP(x) exp_tab[(x)]
51#define LOG(x) log_tab[(x)]
52#define PHT(x, y) { y += x; x += y; }
53#define IPHT(x, y) { x -= y; y -= x; }
54
55static const unsigned int BLOCKSIZE = 8;
56static const unsigned int MAX_ROUNDS = 13;
57
58void SAFER::Base::UncheckedSetKey(const byte *userkey_1, unsigned int length, const NameValuePairs &params)
59{
60 bool strengthened = Strengthened();
61 unsigned int nof_rounds = params.GetIntValueWithDefault(Name::Rounds(), length == 8 ? (strengthened ? 8 : 6) : 10);
62
63 const byte *userkey_2 = length == 8 ? userkey_1 : userkey_1 + 8;
64 keySchedule.New(1 + BLOCKSIZE * (1 + 2 * nof_rounds));
65
66 unsigned int i, j;
67 byte *key = keySchedule;
68 SecByteBlock ka(BLOCKSIZE + 1), kb(BLOCKSIZE + 1);
69
70 if (MAX_ROUNDS < nof_rounds)
71 nof_rounds = MAX_ROUNDS;
72 *key++ = (unsigned char)nof_rounds;
73 ka[BLOCKSIZE] = 0;
74 kb[BLOCKSIZE] = 0;
75 for (j = 0; j < BLOCKSIZE; j++)
76 {
77 ka[BLOCKSIZE] ^= ka[j] = rotlConstant<5>(userkey_1[j]);
78 kb[BLOCKSIZE] ^= kb[j] = *key++ = userkey_2[j];
79 }
80
81 for (i = 1; i <= nof_rounds; i++)
82 {
83 for (j = 0; j < BLOCKSIZE + 1; j++)
84 {
85 ka[j] = rotlConstant<6>(ka[j]);
86 kb[j] = rotlConstant<6>(kb[j]);
87 }
88 for (j = 0; j < BLOCKSIZE; j++)
89 if (strengthened)
90 *key++ = (ka[(j + 2 * i - 1) % (BLOCKSIZE + 1)]
91 + exp_tab[exp_tab[18 * i + j + 1]]) & 0xFF;
92 else
93 *key++ = (ka[j] + exp_tab[exp_tab[18 * i + j + 1]]) & 0xFF;
94 for (j = 0; j < BLOCKSIZE; j++)
95 if (strengthened)
96 *key++ = (kb[(j + 2 * i) % (BLOCKSIZE + 1)]
97 + exp_tab[exp_tab[18 * i + j + 10]]) & 0xFF;
98 else
99 *key++ = (kb[j] + exp_tab[exp_tab[18 * i + j + 10]]) & 0xFF;
100 }
101}
102
103typedef BlockGetAndPut<byte, BigEndian> Block;
104
105void SAFER::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
106{
107 byte a, b, c, d, e, f, g, h, t;
108 const byte *key = keySchedule+1;
109 unsigned int round = keySchedule[0];
110
111 Block::Get(inBlock)(a)(b)(c)(d)(e)(f)(g)(h);
112 while(round--)
113 {
114 a ^= key[0]; b += key[1]; c += key[2]; d ^= key[3];
115 e ^= key[4]; f += key[5]; g += key[6]; h ^= key[7];
116 a = EXP(a) + key[ 8]; b = LOG(b) ^ key[ 9];
117 c = LOG(c) ^ key[10]; d = EXP(d) + key[11];
118 e = EXP(e) + key[12]; f = LOG(f) ^ key[13];
119 g = LOG(g) ^ key[14]; h = EXP(h) + key[15];
120 key += 16;
121 PHT(a, b); PHT(c, d); PHT(e, f); PHT(g, h);
122 PHT(a, c); PHT(e, g); PHT(b, d); PHT(f, h);
123 PHT(a, e); PHT(b, f); PHT(c, g); PHT(d, h);
124 t = b; b = e; e = c; c = t; t = d; d = f; f = g; g = t;
125 }
126 a ^= key[0]; b += key[1]; c += key[2]; d ^= key[3];
127 e ^= key[4]; f += key[5]; g += key[6]; h ^= key[7];
128 Block::Put(xorBlock, outBlock)(a)(b)(c)(d)(e)(f)(g)(h);
129}
130
131void SAFER::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
132{
133 byte a, b, c, d, e, f, g, h, t;
134 unsigned int round = keySchedule[0];
135 const byte *key = keySchedule + BLOCKSIZE * (1 + 2 * round) - 7;
136
137 Block::Get(inBlock)(a)(b)(c)(d)(e)(f)(g)(h);
138 h ^= key[7]; g -= key[6]; f -= key[5]; e ^= key[4];
139 d ^= key[3]; c -= key[2]; b -= key[1]; a ^= key[0];
140 while (round--)
141 {
142 key -= 16;
143 t = e; e = b; b = c; c = t; t = f; f = d; d = g; g = t;
144 IPHT(a, e); IPHT(b, f); IPHT(c, g); IPHT(d, h);
145 IPHT(a, c); IPHT(e, g); IPHT(b, d); IPHT(f, h);
146 IPHT(a, b); IPHT(c, d); IPHT(e, f); IPHT(g, h);
147 h -= key[15]; g ^= key[14]; f ^= key[13]; e -= key[12];
148 d -= key[11]; c ^= key[10]; b ^= key[9]; a -= key[8];
149 h = LOG(h) ^ key[7]; g = EXP(g) - key[6];
150 f = EXP(f) - key[5]; e = LOG(e) ^ key[4];
151 d = LOG(d) ^ key[3]; c = EXP(c) - key[2];
152 b = EXP(b) - key[1]; a = LOG(a) ^ key[0];
153 }
154 Block::Put(xorBlock, outBlock)(a)(b)(c)(d)(e)(f)(g)(h);
155}
156
157NAMESPACE_END
argnames.h
Standard names for retrieving values by name when working with NameValuePairs.
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:322
NameValuePairs::GetIntValueWithDefault
CRYPTOPP_DLL int GetIntValueWithDefault(const char *name, int defaultValue) const
Get a named value with type int, with default.
Definition: cryptlib.h:424
PutBlock
Access a block of memory.
Definition: misc.h:2807
SAFER::Base::UncheckedSetKey
void UncheckedSetKey(const byte *userkey, unsigned int length, const NameValuePairs &params)
Sets the key for this object without performing parameter validation.
Definition: safer.cpp:58
SAFER::Dec::ProcessAndXorBlock
void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
Encrypt or decrypt a block.
Definition: safer.cpp:131
SAFER::Enc::ProcessAndXorBlock
void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
Encrypt or decrypt a block.
Definition: safer.cpp:105
SecBlock::New
void New(size_type newSize)
Change size without preserving contents.
Definition: secblock.h:1126
SecByteBlock
SecBlock<byte> typedef.
Definition: secblock.h:1226
misc.h
Utility functions for the Crypto++ library.
CryptoPP
Crypto++ library namespace.
Name::Rounds
const char * Rounds()
int
Definition: argnames.h:24
pch.h
Precompiled header file.
safer.h
Classes for the SAFER and SAFER-K block ciphers.
BlockGetAndPut
Access a block of memory.
Definition: misc.h:2844
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