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1 | /* -*-c-*- |
2 | * |
3 | * $Id: square.c,v 1.1 2000/07/15 20:51:58 mdw Exp $ |
4 | * |
5 | * The Square block cipher |
6 | * |
7 | * (c) 2000 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: square.c,v $ |
33 | * Revision 1.1 2000/07/15 20:51:58 mdw |
34 | * New block cipher. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <assert.h> |
41 | #include <stdio.h> |
42 | |
43 | #include <mLib/bits.h> |
44 | |
45 | #include "blkc.h" |
46 | #include "gcipher.h" |
47 | #include "paranoia.h" |
48 | #include "square.h" |
49 | #include "square-tab.h" |
50 | |
51 | /*----- Global variables --------------------------------------------------*/ |
52 | |
53 | const octet square_keysz[] = { KSZ_RANGE, SQUARE_KEYSZ, 4, 16, 4 }; |
54 | |
55 | /*----- Constant tables ---------------------------------------------------*/ |
56 | |
57 | static const octet S[256] = SQUARE_S, SI[256] = SQUARE_SI; |
58 | static const uint32 T[4][256] = SQUARE_T, TI[4][256] = SQUARE_TI; |
59 | static const uint32 U[4][256] = SQUARE_U; |
60 | static const octet rcon[] = SQUARE_RCON; |
61 | |
62 | /*----- Main code ---------------------------------------------------------*/ |
63 | |
64 | #define BYTESUB(x, s) \ |
65 | (s[U8((x) >> 24)] << 24 | s[U8((x) >> 16)] << 16 | \ |
66 | s[U8((x) >> 8)] << 8 | s[U8((x) >> 0)] << 0) |
67 | |
68 | /* --- @square_init@ --- * |
69 | * |
70 | * Arguments: @square_ctx *k@ = pointer to context to initialize |
71 | * @const void *buf@ = pointer to buffer of key material |
72 | * @size_t sz@ = size of the key material |
73 | * |
74 | * Returns: --- |
75 | * |
76 | * Use: Initializes a Square context with a particular key. Square |
77 | * keys must be a multiple of 32 bits long, and may be at most |
78 | * 128 bits. |
79 | */ |
80 | |
81 | void square_init(square_ctx *k, const void *buf, size_t sz) |
82 | { |
83 | unsigned nk, nr, nw; |
84 | unsigned i, j, jj; |
85 | const octet *p; |
86 | uint32 ww; |
87 | uint32 kk[SQUARE_KWORDS]; |
88 | |
89 | /* --- Sort out the key size --- */ |
90 | |
91 | KSZ_ASSERT(square, sz); |
92 | nk = sz / 4; |
93 | |
94 | /* --- Fetch the first key words out --- */ |
95 | |
96 | p = buf; |
97 | for (i = 0; i < nk; i++) { |
98 | kk[i] = LOAD32_L(p); |
99 | p += 4; |
100 | } |
101 | nr = 8; |
102 | |
103 | /* --- Expand this material to fill the rest of the table --- */ |
104 | |
105 | nw = (nr + 1) * 4; |
106 | ww = kk[i - 1]; |
107 | p = rcon; |
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]; |
122 | k->w[i] = (U[0][U8(w >> 0)] ^ U[1][U8(w >> 8)] ^ |
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 | |
151 | #define EROUND(aa, bb, cc, dd, a, b, c, d, w) do { \ |
152 | aa = (T[0][U8(a >> 0)] ^ T[1][U8(b >> 0)] ^ \ |
153 | T[2][U8(c >> 0)] ^ T[3][U8(d >> 0)]) ^ *w++; \ |
154 | bb = (T[0][U8(a >> 8)] ^ T[1][U8(b >> 8)] ^ \ |
155 | T[2][U8(c >> 8)] ^ T[3][U8(d >> 8)]) ^ *w++; \ |
156 | cc = (T[0][U8(a >> 16)] ^ T[1][U8(b >> 16)] ^ \ |
157 | T[2][U8(c >> 16)] ^ T[3][U8(d >> 16)]) ^ *w++; \ |
158 | dd = (T[0][U8(a >> 24)] ^ T[1][U8(b >> 24)] ^ \ |
159 | T[2][U8(c >> 24)] ^ T[3][U8(d >> 24)]) ^ *w++; \ |
160 | } while (0) |
161 | |
162 | #define DROUND(aa, bb, cc, dd, a, b, c, d, w) do { \ |
163 | aa = (TI[0][U8(a >> 0)] ^ TI[1][U8(b >> 0)] ^ \ |
164 | TI[2][U8(c >> 0)] ^ TI[3][U8(d >> 0)]) ^ *w++; \ |
165 | bb = (TI[0][U8(a >> 8)] ^ TI[1][U8(b >> 8)] ^ \ |
166 | TI[2][U8(c >> 8)] ^ TI[3][U8(d >> 8)]) ^ *w++; \ |
167 | cc = (TI[0][U8(a >> 16)] ^ TI[1][U8(b >> 16)] ^ \ |
168 | TI[2][U8(c >> 16)] ^ TI[3][U8(d >> 16)]) ^ *w++; \ |
169 | dd = (TI[0][U8(a >> 24)] ^ TI[1][U8(b >> 24)] ^ \ |
170 | TI[2][U8(c >> 24)] ^ TI[3][U8(d >> 24)]) ^ *w++; \ |
171 | } while (0) |
172 | |
173 | void square_eblk(const square_ctx *k, const uint32 *s, uint32 *dst) |
174 | { |
175 | uint32 a = s[0], b = s[1], c = s[2], d = s[3]; |
176 | uint32 aa, bb, cc, dd; |
177 | uint32 *w = k->w; |
178 | |
179 | a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++; |
180 | |
181 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
182 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
183 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
184 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
185 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
186 | EROUND(a, b, c, d, aa, bb, cc, dd, w); |
187 | EROUND(aa, bb, cc, dd, a, b, c, d, w); |
188 | |
189 | a = ((S[U8(aa >> 0)] << 0) ^ (S[U8(bb >> 0)] << 8) ^ |
190 | (S[U8(cc >> 0)] << 16) ^ (S[U8(dd >> 0)] << 24)) ^ *w++; |
191 | b = ((S[U8(aa >> 8)] << 0) ^ (S[U8(bb >> 8)] << 8) ^ |
192 | (S[U8(cc >> 8)] << 16) ^ (S[U8(dd >> 8)] << 24)) ^ *w++; |
193 | c = ((S[U8(aa >> 16)] << 0) ^ (S[U8(bb >> 16)] << 8) ^ |
194 | (S[U8(cc >> 16)] << 16) ^ (S[U8(dd >> 16)] << 24)) ^ *w++; |
195 | d = ((S[U8(aa >> 24)] << 0) ^ (S[U8(bb >> 24)] << 8) ^ |
196 | (S[U8(cc >> 24)] << 16) ^ (S[U8(dd >> 24)] << 24)) ^ *w++; |
197 | |
198 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; |
199 | } |
200 | |
201 | void square_dblk(const square_ctx *k, const uint32 *s, uint32 *dst) |
202 | { |
203 | uint32 a = s[0], b = s[1], c = s[2], d = s[3]; |
204 | uint32 aa, bb, cc, dd; |
205 | uint32 *w = k->wi; |
206 | |
207 | a ^= *w++; b ^= *w++; c ^= *w++; d ^= *w++; |
208 | |
209 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
210 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
211 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
212 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
213 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
214 | DROUND(a, b, c, d, aa, bb, cc, dd, w); |
215 | DROUND(aa, bb, cc, dd, a, b, c, d, w); |
216 | |
217 | a = ((SI[U8(aa >> 0)] << 0) ^ (SI[U8(bb >> 0)] << 8) ^ |
218 | (SI[U8(cc >> 0)] << 16) ^ (SI[U8(dd >> 0)] << 24)) ^ *w++; |
219 | b = ((SI[U8(aa >> 8)] << 0) ^ (SI[U8(bb >> 8)] << 8) ^ |
220 | (SI[U8(cc >> 8)] << 16) ^ (SI[U8(dd >> 8)] << 24)) ^ *w++; |
221 | c = ((SI[U8(aa >> 16)] << 0) ^ (SI[U8(bb >> 16)] << 8) ^ |
222 | (SI[U8(cc >> 16)] << 16) ^ (SI[U8(dd >> 16)] << 24)) ^ *w++; |
223 | d = ((SI[U8(aa >> 24)] << 0) ^ (SI[U8(bb >> 24)] << 8) ^ |
224 | (SI[U8(cc >> 24)] << 16) ^ (SI[U8(dd >> 24)] << 24)) ^ *w++; |
225 | |
226 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; |
227 | } |
228 | |
229 | BLKC_TEST(SQUARE, square) |
230 | |
231 | /*----- That's all, folks -------------------------------------------------*/ |