3 * $Id: square.c,v 1.2 2001/05/07 15:44:02 mdw Exp $
5 * The Square block cipher
7 * (c) 2000 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.2 2001/05/07 15:44:02 mdw
34 * Simplify implementation.
36 * Revision 1.1 2000/07/15 20:51:58 mdw
41 /*----- Header files ------------------------------------------------------*/
46 #include <mLib/bits.h>
52 #include "square-tab.h"
54 /*----- Global variables --------------------------------------------------*/
56 const octet square_keysz
[] = { KSZ_RANGE
, SQUARE_KEYSZ
, 4, 16, 4 };
58 /*----- Constant tables ---------------------------------------------------*/
60 static const octet S
[256] = SQUARE_S
, SI
[256] = SQUARE_SI
;
61 static const uint32 T
[4][256] = SQUARE_T
, TI
[4][256] = SQUARE_TI
;
62 static const uint32 U
[4][256] = SQUARE_U
;
63 static const octet rcon
[] = SQUARE_RCON
;
65 /*----- Main code ---------------------------------------------------------*/
67 /* --- @square_init@ --- *
69 * Arguments: @square_ctx *k@ = pointer to context to initialize
70 * @const void *buf@ = pointer to buffer of key material
71 * @size_t sz@ = size of the key material
75 * Use: Initializes a Square context with a particular key. Square
76 * keys must be a multiple of 32 bits long, and may be at most
80 void square_init(square_ctx
*k
, const void *buf
, size_t sz
)
86 uint32 kk
[SQUARE_KWORDS
];
88 /* --- Sort out the key size --- */
90 KSZ_ASSERT(square
, sz
);
93 /* --- Fetch the first key words out --- */
96 for (i
= 0; i
< nk
; i
++) {
102 /* --- Expand this material to fill the rest of the table --- */
107 for (; i
< nw
; i
++) {
108 uint32 w
= kk
[i
- nk
];
117 /* --- Make the encryption and decryption keys --- */
119 for (i
= 0; i
< nr
* 4; i
++) {
121 k
->w
[i
] = (U
[0][U8(w
>> 0)] ^ U
[1][U8(w
>> 8)] ^
122 U
[2][U8(w
>> 16)] ^ U
[3][U8(w
>> 24)]);
128 for (i
= 0; i
< nr
* 4; i
+= 4) {
130 for (j
= 0; j
< 4; j
++)
131 k
->wi
[i
+ j
] = kk
[jj
+ j
];
133 for (j
= 0; j
< 4; j
++)
134 k
->wi
[i
+ j
] = k
->w
[j
];
139 /* --- @square_eblk@, @square_dblk@ --- *
141 * Arguments: @const square_ctx *k@ = pointer to Square context
142 * @const uint32 s[4]@ = pointer to source block
143 * @uint32 d[4]@ = pointer to destination block
147 * Use: Low-level block encryption and decryption.
150 #define SUB(s, sh, a, b, c, d) \
151 (s[U8((a) >> sh)] << 0 | s[U8((b) >> sh)] << 8 | \
152 s[U8((c) >> sh)] << 16 | s[U8((d) >> sh)] << 24)
154 #define MIX(t, sh, a, b, c, d) \
155 (t[0][U8((a) >> sh)] ^ t[1][U8((b) >> sh)] ^ \
156 t[2][U8((c) >> sh)] ^ t[3][U8((d) >> sh)])
158 #define DO(what, t, aa, bb, cc, dd, a, b, c, d, w) do { \
159 aa = what(t, 0, a, b, c, d) ^ *w++; \
160 bb = what(t, 8, a, b, c, d) ^ *w++; \
161 cc = what(t, 16, a, b, c, d) ^ *w++; \
162 dd = what(t, 24, a, b, c, d) ^ *w++; \
165 void square_eblk(const square_ctx
*k
, const uint32
*s
, uint32
*dst
)
167 uint32 a
= s
[0], b
= s
[1], c
= s
[2], d
= s
[3];
168 uint32 aa
, bb
, cc
, dd
;
171 a
^= *w
++; b
^= *w
++; c
^= *w
++; d
^= *w
++;
173 DO(MIX
, T
, aa
, bb
, cc
, dd
, a
, b
, c
, d
, w
);
174 DO(MIX
, T
, a
, b
, c
, d
, aa
, bb
, cc
, dd
, w
);
175 DO(MIX
, T
, aa
, bb
, cc
, dd
, a
, b
, c
, d
, w
);
176 DO(MIX
, T
, a
, b
, c
, d
, aa
, bb
, cc
, dd
, w
);
177 DO(MIX
, T
, aa
, bb
, cc
, dd
, a
, b
, c
, d
, w
);
178 DO(MIX
, T
, a
, b
, c
, d
, aa
, bb
, cc
, dd
, w
);
179 DO(MIX
, T
, aa
, bb
, cc
, dd
, a
, b
, c
, d
, w
);
180 DO(SUB
, S
, a
, b
, c
, d
, aa
, bb
, cc
, dd
, w
);
182 dst
[0] = a
; dst
[1] = b
; dst
[2] = c
; dst
[3] = d
;
185 void square_dblk(const square_ctx
*k
, const uint32
*s
, uint32
*dst
)
187 uint32 a
= s
[0], b
= s
[1], c
= s
[2], d
= s
[3];
188 uint32 aa
, bb
, cc
, dd
;
191 a
^= *w
++; b
^= *w
++; c
^= *w
++; d
^= *w
++;
193 DO(MIX
, TI
, aa
, bb
, cc
, dd
, a
, b
, c
, d
, w
);
194 DO(MIX
, TI
, a
, b
, c
, d
, aa
, bb
, cc
, dd
, w
);
195 DO(MIX
, TI
, aa
, bb
, cc
, dd
, a
, b
, c
, d
, w
);
196 DO(MIX
, TI
, a
, b
, c
, d
, aa
, bb
, cc
, dd
, w
);
197 DO(MIX
, TI
, aa
, bb
, cc
, dd
, a
, b
, c
, d
, w
);
198 DO(MIX
, TI
, a
, b
, c
, d
, aa
, bb
, cc
, dd
, w
);
199 DO(MIX
, TI
, aa
, bb
, cc
, dd
, a
, b
, c
, d
, w
);
200 DO(SUB
, SI
, a
, b
, c
, d
, aa
, bb
, cc
, dd
, w
);
202 dst
[0] = a
; dst
[1] = b
; dst
[2] = c
; dst
[3] = d
;
205 BLKC_TEST(SQUARE
, square
)
207 /*----- That's all, folks -------------------------------------------------*/