Commit | Line | Data |
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8875ece6 | 1 | /* -*-c-*- |
8875ece6 | 2 | * |
3 | * The Square block cipher | |
4 | * | |
5 | * (c) 2000 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
8875ece6 | 9 | * |
10 | * This file is part of Catacomb. | |
11 | * | |
12 | * Catacomb is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU Library General Public License as | |
14 | * published by the Free Software Foundation; either version 2 of the | |
15 | * License, or (at your option) any later version. | |
45c0fd36 | 16 | * |
8875ece6 | 17 | * Catacomb is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | * GNU Library General Public License for more details. | |
45c0fd36 | 21 | * |
8875ece6 | 22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with Catacomb; if not, write to the Free | |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
25 | * MA 02111-1307, USA. | |
26 | */ | |
27 | ||
8875ece6 | 28 | /*----- Header files ------------------------------------------------------*/ |
29 | ||
30 | #include <assert.h> | |
31 | #include <stdio.h> | |
32 | ||
33 | #include <mLib/bits.h> | |
23bbea75 | 34 | #include <mLib/macros.h> |
8875ece6 | 35 | |
36 | #include "blkc.h" | |
37 | #include "gcipher.h" | |
38 | #include "paranoia.h" | |
39 | #include "square.h" | |
8875ece6 | 40 | |
41 | /*----- Global variables --------------------------------------------------*/ | |
42 | ||
43 | const octet square_keysz[] = { KSZ_RANGE, SQUARE_KEYSZ, 4, 16, 4 }; | |
44 | ||
45 | /*----- Constant tables ---------------------------------------------------*/ | |
46 | ||
e5b61a8d MW |
47 | extern const octet square_s[256], square_si[256]; |
48 | extern const uint32 square_t[4][256], square_ti[4][256]; | |
49 | extern const uint32 square_u[4][256]; | |
50 | extern const octet square_rcon[32]; | |
51 | ||
52 | #define S square_s | |
53 | #define SI square_si | |
54 | #define T square_t | |
55 | #define TI square_ti | |
56 | #define U square_u | |
57 | #define RCON square_rcon | |
8875ece6 | 58 | |
59 | /*----- Main code ---------------------------------------------------------*/ | |
60 | ||
8875ece6 | 61 | /* --- @square_init@ --- * |
62 | * | |
63 | * Arguments: @square_ctx *k@ = pointer to context to initialize | |
64 | * @const void *buf@ = pointer to buffer of key material | |
65 | * @size_t sz@ = size of the key material | |
66 | * | |
67 | * Returns: --- | |
68 | * | |
69 | * Use: Initializes a Square context with a particular key. Square | |
70 | * keys must be a multiple of 32 bits long, and may be at most | |
71 | * 128 bits. | |
72 | */ | |
73 | ||
74 | void square_init(square_ctx *k, const void *buf, size_t sz) | |
75 | { | |
76 | unsigned nk, nr, nw; | |
77 | unsigned i, j, jj; | |
78 | const octet *p; | |
79 | uint32 ww; | |
80 | uint32 kk[SQUARE_KWORDS]; | |
81 | ||
82 | /* --- Sort out the key size --- */ | |
83 | ||
84 | KSZ_ASSERT(square, sz); | |
85 | nk = sz / 4; | |
86 | ||
87 | /* --- Fetch the first key words out --- */ | |
88 | ||
89 | p = buf; | |
90 | for (i = 0; i < nk; i++) { | |
91 | kk[i] = LOAD32_L(p); | |
92 | p += 4; | |
93 | } | |
94 | nr = 8; | |
95 | ||
aa02ed36 MW |
96 | /* --- GCC complains about an out-of-bounds subscript here --- * |
97 | * | |
23bbea75 MW |
98 | * This is impossible. Thanks to @KSZ_ASSERT@, we know that @4 <= sz <= |
99 | * 16@ and hence @1 <= i <= nk <= 4@; but @SQUARE_KWORDS == 36@. | |
aa02ed36 MW |
100 | */ |
101 | ||
23bbea75 | 102 | ww = MUFFLE_WARNINGS_EXPR(GCC_WARNING("-Warray-bounds"), kk[i - 1]); |
aa02ed36 | 103 | |
8875ece6 | 104 | /* --- Expand this material to fill the rest of the table --- */ |
105 | ||
106 | nw = (nr + 1) * 4; | |
e5b61a8d | 107 | p = RCON; |
8875ece6 | 108 | for (; i < nw; i++) { |
109 | uint32 w = kk[i - nk]; | |
110 | if (i % nk == 0) { | |
111 | ww = ROR32(ww, 8); | |
112 | w ^= ww ^ *p++; | |
113 | } else | |
114 | w ^= ww; | |
115 | kk[i] = ww = w; | |
116 | } | |
117 | ||
118 | /* --- Make the encryption and decryption keys --- */ | |
119 | ||
120 | for (i = 0; i < nr * 4; i++) { | |
121 | uint32 w = kk[i]; | |
45c0fd36 | 122 | k->w[i] = (U[0][U8(w >> 0)] ^ U[1][U8(w >> 8)] ^ |
8875ece6 | 123 | U[2][U8(w >> 16)] ^ U[3][U8(w >> 24)]); |
124 | } | |
125 | for (; i < nw; i++) | |
126 | k->w[i] = kk[i]; | |
127 | ||
128 | jj = nw; | |
129 | for (i = 0; i < nr * 4; i += 4) { | |
130 | jj -= 4; | |
131 | for (j = 0; j < 4; j++) | |
132 | k->wi[i + j] = kk[jj + j]; | |
133 | } | |
134 | for (j = 0; j < 4; j++) | |
135 | k->wi[i + j] = k->w[j]; | |
136 | ||
137 | BURN(kk); | |
138 | } | |
139 | ||
140 | /* --- @square_eblk@, @square_dblk@ --- * | |
141 | * | |
142 | * Arguments: @const square_ctx *k@ = pointer to Square context | |
143 | * @const uint32 s[4]@ = pointer to source block | |
144 | * @uint32 d[4]@ = pointer to destination block | |
145 | * | |
146 | * Returns: --- | |
147 | * | |
148 | * Use: Low-level block encryption and decryption. | |
149 | */ | |
150 | ||
b14a0768 | 151 | #define SUB(s, sh, a, b, c, d) \ |
45c0fd36 | 152 | (s[U8((a) >> sh)] << 0 | s[U8((b) >> sh)] << 8 | \ |
b14a0768 | 153 | s[U8((c) >> sh)] << 16 | s[U8((d) >> sh)] << 24) |
154 | ||
155 | #define MIX(t, sh, a, b, c, d) \ | |
156 | (t[0][U8((a) >> sh)] ^ t[1][U8((b) >> sh)] ^ \ | |
157 | t[2][U8((c) >> sh)] ^ t[3][U8((d) >> sh)]) | |
8875ece6 | 158 | |
b14a0768 | 159 | #define DO(what, t, aa, bb, cc, dd, a, b, c, d, w) do { \ |
45c0fd36 MW |
160 | aa = what(t, 0, a, b, c, d) ^ *w++; \ |
161 | bb = what(t, 8, a, b, c, d) ^ *w++; \ | |
b14a0768 | 162 | cc = what(t, 16, a, b, c, d) ^ *w++; \ |
163 | dd = what(t, 24, a, b, c, d) ^ *w++; \ | |
8875ece6 | 164 | } while (0) |
165 | ||
166 | void square_eblk(const square_ctx *k, const uint32 *s, uint32 *dst) | |
167 | { | |
168 | uint32 a = s[0], b = s[1], c = s[2], d = s[3]; | |
169 | uint32 aa, bb, cc, dd; | |
78ec50fa | 170 | const uint32 *w = k->w; |
8875ece6 | 171 | |
172 | a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++; | |
173 | ||
b14a0768 | 174 | DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w); |
175 | DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w); | |
176 | DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w); | |
177 | DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w); | |
178 | DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w); | |
179 | DO(MIX, T, a, b, c, d, aa, bb, cc, dd, w); | |
180 | DO(MIX, T, aa, bb, cc, dd, a, b, c, d, w); | |
181 | DO(SUB, S, a, b, c, d, aa, bb, cc, dd, w); | |
8875ece6 | 182 | |
183 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; | |
184 | } | |
185 | ||
186 | void square_dblk(const square_ctx *k, const uint32 *s, uint32 *dst) | |
187 | { | |
188 | uint32 a = s[0], b = s[1], c = s[2], d = s[3]; | |
189 | uint32 aa, bb, cc, dd; | |
78ec50fa | 190 | const uint32 *w = k->wi; |
8875ece6 | 191 | |
192 | a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++; | |
193 | ||
b14a0768 | 194 | DO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w); |
195 | DO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w); | |
196 | DO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w); | |
197 | DO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w); | |
198 | DO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w); | |
199 | DO(MIX, TI, a, b, c, d, aa, bb, cc, dd, w); | |
200 | DO(MIX, TI, aa, bb, cc, dd, a, b, c, d, w); | |
201 | DO(SUB, SI, a, b, c, d, aa, bb, cc, dd, w); | |
8875ece6 | 202 | |
203 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; | |
204 | } | |
205 | ||
206 | BLKC_TEST(SQUARE, square) | |
207 | ||
208 | /*----- That's all, folks -------------------------------------------------*/ |