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Raise WARNS to 6.
[dragonfly.git] / sys / opencrypto / cast.c
blobbd82bfa30a5b0b5f97a45e1ba49567313f85c95b
1 /* $FreeBSD: src/sys/opencrypto/cast.c,v 1.1.2.1 2002/11/21 23:34:23 sam Exp $ */
2 /* $DragonFly: src/sys/opencrypto/cast.c,v 1.2 2003/06/17 04:28:54 dillon Exp $ */
3 /* $OpenBSD: cast.c,v 1.2 2000/06/06 06:49:47 deraadt Exp $ */
4
5 /*
6 * CAST-128 in C
7 * Written by Steve Reid <sreid@sea-to-sky.net>
8 * 100% Public Domain - no warranty
9 * Released 1997.10.11
10 */
11
12 #include <sys/types.h>
13 #include <opencrypto/cast.h>
14 #include <opencrypto/castsb.h>
15
16 /* Macros to access 8-bit bytes out of a 32-bit word */
17 #define U_INT8_Ta(x) ( (u_int8_t) (x>>24) )
18 #define U_INT8_Tb(x) ( (u_int8_t) ((x>>16)&255) )
19 #define U_INT8_Tc(x) ( (u_int8_t) ((x>>8)&255) )
20 #define U_INT8_Td(x) ( (u_int8_t) ((x)&255) )
21
22 /* Circular left shift */
23 #define ROL(x, n) ( ((x)<<(n)) | ((x)>>(32-(n))) )
24
25 /* CAST-128 uses three different round functions */
26 #define F1(l, r, i) \
27 t = ROL(key->xkey[i] + r, key->xkey[i+16]); \
28 l ^= ((cast_sbox1[U_INT8_Ta(t)] ^ cast_sbox2[U_INT8_Tb(t)]) - \
29 cast_sbox3[U_INT8_Tc(t)]) + cast_sbox4[U_INT8_Td(t)];
30 #define F2(l, r, i) \
31 t = ROL(key->xkey[i] ^ r, key->xkey[i+16]); \
32 l ^= ((cast_sbox1[U_INT8_Ta(t)] - cast_sbox2[U_INT8_Tb(t)]) + \
33 cast_sbox3[U_INT8_Tc(t)]) ^ cast_sbox4[U_INT8_Td(t)];
34 #define F3(l, r, i) \
35 t = ROL(key->xkey[i] - r, key->xkey[i+16]); \
36 l ^= ((cast_sbox1[U_INT8_Ta(t)] + cast_sbox2[U_INT8_Tb(t)]) ^ \
37 cast_sbox3[U_INT8_Tc(t)]) - cast_sbox4[U_INT8_Td(t)];
38
39
40 /***** Encryption Function *****/
41
42 void cast_encrypt(cast_key* key, u_int8_t* inblock, u_int8_t* outblock)
43 {
44 u_int32_t t, l, r;
45
46 /* Get inblock into l,r */
47 l = ((u_int32_t)inblock[0] << 24) | ((u_int32_t)inblock[1] << 16) |
48 ((u_int32_t)inblock[2] << 8) | (u_int32_t)inblock[3];
49 r = ((u_int32_t)inblock[4] << 24) | ((u_int32_t)inblock[5] << 16) |
50 ((u_int32_t)inblock[6] << 8) | (u_int32_t)inblock[7];
51 /* Do the work */
52 F1(l, r, 0);
53 F2(r, l, 1);
54 F3(l, r, 2);
55 F1(r, l, 3);
56 F2(l, r, 4);
57 F3(r, l, 5);
58 F1(l, r, 6);
59 F2(r, l, 7);
60 F3(l, r, 8);
61 F1(r, l, 9);
62 F2(l, r, 10);
63 F3(r, l, 11);
64 /* Only do full 16 rounds if key length > 80 bits */
65 if (key->rounds > 12) {
66 F1(l, r, 12);
67 F2(r, l, 13);
68 F3(l, r, 14);
69 F1(r, l, 15);
70 }
71 /* Put l,r into outblock */
72 outblock[0] = U_INT8_Ta(r);
73 outblock[1] = U_INT8_Tb(r);
74 outblock[2] = U_INT8_Tc(r);
75 outblock[3] = U_INT8_Td(r);
76 outblock[4] = U_INT8_Ta(l);
77 outblock[5] = U_INT8_Tb(l);
78 outblock[6] = U_INT8_Tc(l);
79 outblock[7] = U_INT8_Td(l);
80 /* Wipe clean */
81 t = l = r = 0;
82 }
83
84
85 /***** Decryption Function *****/
86
87 void cast_decrypt(cast_key* key, u_int8_t* inblock, u_int8_t* outblock)
88 {
89 u_int32_t t, l, r;
90
91 /* Get inblock into l,r */
92 r = ((u_int32_t)inblock[0] << 24) | ((u_int32_t)inblock[1] << 16) |
93 ((u_int32_t)inblock[2] << 8) | (u_int32_t)inblock[3];
94 l = ((u_int32_t)inblock[4] << 24) | ((u_int32_t)inblock[5] << 16) |
95 ((u_int32_t)inblock[6] << 8) | (u_int32_t)inblock[7];
96 /* Do the work */
97 /* Only do full 16 rounds if key length > 80 bits */
98 if (key->rounds > 12) {
99 F1(r, l, 15);
100 F3(l, r, 14);
101 F2(r, l, 13);
102 F1(l, r, 12);
103 }
104 F3(r, l, 11);
105 F2(l, r, 10);
106 F1(r, l, 9);
107 F3(l, r, 8);
108 F2(r, l, 7);
109 F1(l, r, 6);
110 F3(r, l, 5);
111 F2(l, r, 4);
112 F1(r, l, 3);
113 F3(l, r, 2);
114 F2(r, l, 1);
115 F1(l, r, 0);
116 /* Put l,r into outblock */
117 outblock[0] = U_INT8_Ta(l);
118 outblock[1] = U_INT8_Tb(l);
119 outblock[2] = U_INT8_Tc(l);
120 outblock[3] = U_INT8_Td(l);
121 outblock[4] = U_INT8_Ta(r);
122 outblock[5] = U_INT8_Tb(r);
123 outblock[6] = U_INT8_Tc(r);
124 outblock[7] = U_INT8_Td(r);
125 /* Wipe clean */
126 t = l = r = 0;
127 }
128
129
130 /***** Key Schedual *****/
131
132 void cast_setkey(cast_key* key, u_int8_t* rawkey, int keybytes)
133 {
134 u_int32_t t[4], z[4], x[4];
135 int i;
136
137 /* Set number of rounds to 12 or 16, depending on key length */
138 key->rounds = (keybytes <= 10 ? 12 : 16);
139
140 /* Copy key to workspace x */
141 for (i = 0; i < 4; i++) {
142 x[i] = 0;
143 if ((i*4+0) < keybytes) x[i] = (u_int32_t)rawkey[i*4+0] << 24;
144 if ((i*4+1) < keybytes) x[i] |= (u_int32_t)rawkey[i*4+1] << 16;
145 if ((i*4+2) < keybytes) x[i] |= (u_int32_t)rawkey[i*4+2] << 8;
146 if ((i*4+3) < keybytes) x[i] |= (u_int32_t)rawkey[i*4+3];
147 }
148 /* Generate 32 subkeys, four at a time */
149 for (i = 0; i < 32; i+=4) {
150 switch (i & 4) {
151 case 0:
152 t[0] = z[0] = x[0] ^ cast_sbox5[U_INT8_Tb(x[3])] ^
153 cast_sbox6[U_INT8_Td(x[3])] ^ cast_sbox7[U_INT8_Ta(x[3])] ^
154 cast_sbox8[U_INT8_Tc(x[3])] ^ cast_sbox7[U_INT8_Ta(x[2])];
155 t[1] = z[1] = x[2] ^ cast_sbox5[U_INT8_Ta(z[0])] ^
156 cast_sbox6[U_INT8_Tc(z[0])] ^ cast_sbox7[U_INT8_Tb(z[0])] ^
157 cast_sbox8[U_INT8_Td(z[0])] ^ cast_sbox8[U_INT8_Tc(x[2])];
158 t[2] = z[2] = x[3] ^ cast_sbox5[U_INT8_Td(z[1])] ^
159 cast_sbox6[U_INT8_Tc(z[1])] ^ cast_sbox7[U_INT8_Tb(z[1])] ^
160 cast_sbox8[U_INT8_Ta(z[1])] ^ cast_sbox5[U_INT8_Tb(x[2])];
161 t[3] = z[3] = x[1] ^ cast_sbox5[U_INT8_Tc(z[2])] ^
162 cast_sbox6[U_INT8_Tb(z[2])] ^ cast_sbox7[U_INT8_Td(z[2])] ^
163 cast_sbox8[U_INT8_Ta(z[2])] ^ cast_sbox6[U_INT8_Td(x[2])];
164 break;
165 case 4:
166 t[0] = x[0] = z[2] ^ cast_sbox5[U_INT8_Tb(z[1])] ^
167 cast_sbox6[U_INT8_Td(z[1])] ^ cast_sbox7[U_INT8_Ta(z[1])] ^
168 cast_sbox8[U_INT8_Tc(z[1])] ^ cast_sbox7[U_INT8_Ta(z[0])];
169 t[1] = x[1] = z[0] ^ cast_sbox5[U_INT8_Ta(x[0])] ^
170 cast_sbox6[U_INT8_Tc(x[0])] ^ cast_sbox7[U_INT8_Tb(x[0])] ^
171 cast_sbox8[U_INT8_Td(x[0])] ^ cast_sbox8[U_INT8_Tc(z[0])];
172 t[2] = x[2] = z[1] ^ cast_sbox5[U_INT8_Td(x[1])] ^
173 cast_sbox6[U_INT8_Tc(x[1])] ^ cast_sbox7[U_INT8_Tb(x[1])] ^
174 cast_sbox8[U_INT8_Ta(x[1])] ^ cast_sbox5[U_INT8_Tb(z[0])];
175 t[3] = x[3] = z[3] ^ cast_sbox5[U_INT8_Tc(x[2])] ^
176 cast_sbox6[U_INT8_Tb(x[2])] ^ cast_sbox7[U_INT8_Td(x[2])] ^
177 cast_sbox8[U_INT8_Ta(x[2])] ^ cast_sbox6[U_INT8_Td(z[0])];
178 break;
179 }
180 switch (i & 12) {
181 case 0:
182 case 12:
183 key->xkey[i+0] = cast_sbox5[U_INT8_Ta(t[2])] ^ cast_sbox6[U_INT8_Tb(t[2])] ^
184 cast_sbox7[U_INT8_Td(t[1])] ^ cast_sbox8[U_INT8_Tc(t[1])];
185 key->xkey[i+1] = cast_sbox5[U_INT8_Tc(t[2])] ^ cast_sbox6[U_INT8_Td(t[2])] ^
186 cast_sbox7[U_INT8_Tb(t[1])] ^ cast_sbox8[U_INT8_Ta(t[1])];
187 key->xkey[i+2] = cast_sbox5[U_INT8_Ta(t[3])] ^ cast_sbox6[U_INT8_Tb(t[3])] ^
188 cast_sbox7[U_INT8_Td(t[0])] ^ cast_sbox8[U_INT8_Tc(t[0])];
189 key->xkey[i+3] = cast_sbox5[U_INT8_Tc(t[3])] ^ cast_sbox6[U_INT8_Td(t[3])] ^
190 cast_sbox7[U_INT8_Tb(t[0])] ^ cast_sbox8[U_INT8_Ta(t[0])];
191 break;
192 case 4:
193 case 8:
194 key->xkey[i+0] = cast_sbox5[U_INT8_Td(t[0])] ^ cast_sbox6[U_INT8_Tc(t[0])] ^
195 cast_sbox7[U_INT8_Ta(t[3])] ^ cast_sbox8[U_INT8_Tb(t[3])];
196 key->xkey[i+1] = cast_sbox5[U_INT8_Tb(t[0])] ^ cast_sbox6[U_INT8_Ta(t[0])] ^
197 cast_sbox7[U_INT8_Tc(t[3])] ^ cast_sbox8[U_INT8_Td(t[3])];
198 key->xkey[i+2] = cast_sbox5[U_INT8_Td(t[1])] ^ cast_sbox6[U_INT8_Tc(t[1])] ^
199 cast_sbox7[U_INT8_Ta(t[2])] ^ cast_sbox8[U_INT8_Tb(t[2])];
200 key->xkey[i+3] = cast_sbox5[U_INT8_Tb(t[1])] ^ cast_sbox6[U_INT8_Ta(t[1])] ^
201 cast_sbox7[U_INT8_Tc(t[2])] ^ cast_sbox8[U_INT8_Td(t[2])];
202 break;
203 }
204 switch (i & 12) {
205 case 0:
206 key->xkey[i+0] ^= cast_sbox5[U_INT8_Tc(z[0])];
207 key->xkey[i+1] ^= cast_sbox6[U_INT8_Tc(z[1])];
208 key->xkey[i+2] ^= cast_sbox7[U_INT8_Tb(z[2])];
209 key->xkey[i+3] ^= cast_sbox8[U_INT8_Ta(z[3])];
210 break;
211 case 4:
212 key->xkey[i+0] ^= cast_sbox5[U_INT8_Ta(x[2])];
213 key->xkey[i+1] ^= cast_sbox6[U_INT8_Tb(x[3])];
214 key->xkey[i+2] ^= cast_sbox7[U_INT8_Td(x[0])];
215 key->xkey[i+3] ^= cast_sbox8[U_INT8_Td(x[1])];
216 break;
217 case 8:
218 key->xkey[i+0] ^= cast_sbox5[U_INT8_Tb(z[2])];
219 key->xkey[i+1] ^= cast_sbox6[U_INT8_Ta(z[3])];
220 key->xkey[i+2] ^= cast_sbox7[U_INT8_Tc(z[0])];
221 key->xkey[i+3] ^= cast_sbox8[U_INT8_Tc(z[1])];
222 break;
223 case 12:
224 key->xkey[i+0] ^= cast_sbox5[U_INT8_Td(x[0])];
225 key->xkey[i+1] ^= cast_sbox6[U_INT8_Td(x[1])];
226 key->xkey[i+2] ^= cast_sbox7[U_INT8_Ta(x[2])];
227 key->xkey[i+3] ^= cast_sbox8[U_INT8_Tb(x[3])];
228 break;
229 }
230 if (i >= 16) {
231 key->xkey[i+0] &= 31;
232 key->xkey[i+1] &= 31;
233 key->xkey[i+2] &= 31;
234 key->xkey[i+3] &= 31;
235 }
236 }
237 /* Wipe clean */
238 for (i = 0; i < 4; i++) {
239 t[i] = x[i] = z[i] = 0;
240 }
241 }
242
243 /* Made in Canada */
244
DragonFly BSD