Crypto++ 8.2 Free C++ class library of cryptographic schemes

square.cpp
1 // square.cpp - originally written and placed in the public domain by Wei Dai
2 // Based on Paulo S.L.M. Barreto's public domain implementation
3
4 #include "pch.h"
5 #include "config.h"
6
7 #include "square.h"
8 #include "misc.h"
9 #include "gf256.h"
10
11 #if CRYPTOPP_MSC_VERSION
12 # pragma warning(disable: 4244)
13 #endif
14
15 #if CRYPTOPP_GCC_DIAGNOSTIC_AVAILABLE
16 # pragma GCC diagnostic ignored "-Wmissing-braces"
17 #endif
18
19 NAMESPACE_BEGIN(CryptoPP)
20
21 // apply theta to a roundkey
22 static void SquareTransform (word32 in[4], word32 out[4])
23 {
24 static const byte G[4][4] =
25 {
26 0x02U, 0x01U, 0x01U, 0x03U,
27 0x03U, 0x02U, 0x01U, 0x01U,
28 0x01U, 0x03U, 0x02U, 0x01U,
29 0x01U, 0x01U, 0x03U, 0x02U
30 };
31
32 GF256 gf256(0xf5);
33
34 for (int i = 0; i < 4; i++)
35 {
36 word32 temp = 0;
37 for (unsigned int j = 0; j < 4; j++)
38 for (unsigned int k = 0; k < 4; k++)
39 temp ^= (word32)gf256.Multiply(GETBYTE(in[i], 3-k), G[k][j]) << ((3-j)*8);
40 out[i] = temp;
41 }
42 }
43
44 #define roundkeys(i, j) m_roundkeys[(i)*4+(j)]
45 #define roundkeys4(i) (m_roundkeys+(i)*4)
46
47 void Square::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
48 {
49 AssertValidKeyLength(length);
50
51 static const word32 offset[ROUNDS] = {
52 0x01000000UL, 0x02000000UL, 0x04000000UL, 0x08000000UL,
53 0x10000000UL, 0x20000000UL, 0x40000000UL, 0x80000000UL,
54 };
55
56 GetUserKey(BIG_ENDIAN_ORDER, m_roundkeys.data(), KEYLENGTH/4, userKey, KEYLENGTH);
57
58 /* apply the key evolution function */
59 for (int i = 1; i < ROUNDS+1; i++)
60 {
61 roundkeys(i, 0) = roundkeys(i-1, 0) ^ rotlConstant<8>(roundkeys(i-1, 3)) ^ offset[i-1];
62 roundkeys(i, 1) = roundkeys(i-1, 1) ^ roundkeys(i, 0);
63 roundkeys(i, 2) = roundkeys(i-1, 2) ^ roundkeys(i, 1);
64 roundkeys(i, 3) = roundkeys(i-1, 3) ^ roundkeys(i, 2);
65 }
66
67 /* produce the round keys */
68 if (IsForwardTransformation())
69 {
70 for (int i = 0; i < ROUNDS; i++)
71 SquareTransform (roundkeys4(i), roundkeys4(i));
72 }
73 else
74 {
75 for (int i = 0; i < ROUNDS/2; i++)
76 for (int j = 0; j < 4; j++)
77 std::swap(roundkeys(i, j), roundkeys(ROUNDS-i, j));
78 SquareTransform (roundkeys4(ROUNDS), roundkeys4(ROUNDS));
79 }
80 }
81
82 #define MSB(x) (((x) >> 24) & 0xffU) /* most significant byte */
83 #define SSB(x) (((x) >> 16) & 0xffU) /* second in significance */
84 #define TSB(x) (((x) >> 8) & 0xffU) /* third in significance */
85 #define LSB(x) (((x) ) & 0xffU) /* least significant byte */
86
87 #define squareRound(text, temp, T0, T1, T2, T3, roundkey) \
88 { \
89 temp[0] = T0[MSB (text[0])] \
90 ^ T1[MSB (text[1])] \
91 ^ T2[MSB (text[2])] \
92 ^ T3[MSB (text[3])] \
93 ^ roundkey[0]; \
94 temp[1] = T0[SSB (text[0])] \
95 ^ T1[SSB (text[1])] \
96 ^ T2[SSB (text[2])] \
97 ^ T3[SSB (text[3])] \
98 ^ roundkey[1]; \
99 temp[2] = T0[TSB (text[0])] \
100 ^ T1[TSB (text[1])] \
101 ^ T2[TSB (text[2])] \
102 ^ T3[TSB (text[3])] \
103 ^ roundkey[2]; \
104 temp[3] = T0[LSB (text[0])] \
105 ^ T1[LSB (text[1])] \
106 ^ T2[LSB (text[2])] \
107 ^ T3[LSB (text[3])] \
108 ^ roundkey[3]; \
109 } /* squareRound */
110
111 #define squareFinal(text, temp, S, roundkey) \
112 { \
113 text[0] = ((word32) (S[MSB (temp[0])]) << 24) \
114 ^ ((word32) (S[MSB (temp[1])]) << 16) \
115 ^ ((word32) (S[MSB (temp[2])]) << 8) \
116 ^ (word32) (S[MSB (temp[3])]) \
117 ^ roundkey[0]; \
118 text[1] = ((word32) (S[SSB (temp[0])]) << 24) \
119 ^ ((word32) (S[SSB (temp[1])]) << 16) \
120 ^ ((word32) (S[SSB (temp[2])]) << 8) \
121 ^ (word32) (S[SSB (temp[3])]) \
122 ^ roundkey[1]; \
123 text[2] = ((word32) (S[TSB (temp[0])]) << 24) \
124 ^ ((word32) (S[TSB (temp[1])]) << 16) \
125 ^ ((word32) (S[TSB (temp[2])]) << 8) \
126 ^ (word32) (S[TSB (temp[3])]) \
127 ^ roundkey[2]; \
128 text[3] = ((word32) (S[LSB (temp[0])]) << 24) \
129 ^ ((word32) (S[LSB (temp[1])]) << 16) \
130 ^ ((word32) (S[LSB (temp[2])]) << 8) \
131 ^ (word32) (S[LSB (temp[3])]) \
132 ^ roundkey[3]; \
133 } /* squareFinal */
134
135 typedef BlockGetAndPut<word32, BigEndian> Block;
136
137 void Square::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
138 {
139 word32 text[4], temp[4];
140 Block::Get(inBlock)(text[0])(text[1])(text[2])(text[3]);
141
142 /* initial key addition */
143 text[0] ^= roundkeys(0, 0);
144 text[1] ^= roundkeys(0, 1);
145 text[2] ^= roundkeys(0, 2);
146 text[3] ^= roundkeys(0, 3);
147
148 /* ROUNDS - 1 full rounds */
149 for (int i=1; i+1<ROUNDS; i+=2)
150 {
151 squareRound (text, temp, Te[0], Te[1], Te[2], Te[3], roundkeys4(i));
152 squareRound (temp, text, Te[0], Te[1], Te[2], Te[3], roundkeys4(i+1));
153 }
154 squareRound (text, temp, Te[0], Te[1], Te[2], Te[3], roundkeys4(ROUNDS-1));
155
156 /* last round (diffusion becomes only transposition) */
157 squareFinal (text, temp, Se, roundkeys4(ROUNDS));
158
159 Block::Put(xorBlock, outBlock)(text[0])(text[1])(text[2])(text[3]);
160 }
161
162 void Square::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
163 {
164 word32 text[4], temp[4];
165 Block::Get(inBlock)(text[0])(text[1])(text[2])(text[3]);
166
167 /* initial key addition */
168 text[0] ^= roundkeys(0, 0);
169 text[1] ^= roundkeys(0, 1);
170 text[2] ^= roundkeys(0, 2);
171 text[3] ^= roundkeys(0, 3);
172
173 /* ROUNDS - 1 full rounds */
174 for (int i=1; i+1<ROUNDS; i+=2)
175 {
176 squareRound (text, temp, Td[0], Td[1], Td[2], Td[3], roundkeys4(i));
177 squareRound (temp, text, Td[0], Td[1], Td[2], Td[3], roundkeys4(i+1));
178 }
179 squareRound (text, temp, Td[0], Td[1], Td[2], Td[3], roundkeys4(ROUNDS-1));
180
181 /* last round (diffusion becomes only transposition) */
182 squareFinal (text, temp, Sd, roundkeys4(ROUNDS));
183
184 Block::Put(xorBlock, outBlock)(text[0])(text[1])(text[2])(text[3]);
185 }
186
187 NAMESPACE_END
misc.h
Utility functions for the Crypto++ library.
config.h
Library configuration file.
BlockGetAndPut
Access a block of memory.
Definition: misc.h:2587
GF256
GF(256) with polynomial basis.
Definition: gf256.h:15
pch.h
Precompiled header file.
BIG_ENDIAN_ORDER
byte order is big-endian
Definition: cryptlib.h:147
gf256.h
Classes and functions for schemes over GF(256)
PutBlock
Access a block of memory.
Definition: misc.h:2550
CryptoPP
Crypto++ library namespace.
swap
void swap(::SecBlock< T, A > &a, ::SecBlock< T, A > &b)
Swap two SecBlocks.
Definition: secblock.h:1159
square.h
Classes for the Square block cipher.
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:321