2 * Written in 2013 by Gregor Pintar <grpintar@gmail.com>
4 * To the extent possible under law, the author(s) have dedicated
5 * all copyright and related and neighboring rights to this software
6 * to the public domain worldwide.
8 * This software is distributed without any warranty.
10 * You should have received a copy of the CC0 Public Domain Dedication.
11 * If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
14 /* Based on Tom St Denis's implementation */
20 #include <kripto/cast.h>
21 #include <kripto/loadstore.h>
22 #include <kripto/memwipe.h>
23 #include <kripto/block.h>
24 #include <kripto/desc/block.h>
25 #include <kripto/object/block.h>
27 #include <kripto/block/skipjack.h>
31 struct kripto_block_object obj
;
35 static const uint8_t S
[256] =
37 0xA3, 0xD7, 0x09, 0x83, 0xF8, 0x48, 0xF6, 0xF4,
38 0xB3, 0x21, 0x15, 0x78, 0x99, 0xB1, 0xAF, 0xF9,
39 0xE7, 0x2D, 0x4D, 0x8A, 0xCE, 0x4C, 0xCA, 0x2E,
40 0x52, 0x95, 0xD9, 0x1E, 0x4E, 0x38, 0x44, 0x28,
41 0x0A, 0xDF, 0x02, 0xA0, 0x17, 0xF1, 0x60, 0x68,
42 0x12, 0xB7, 0x7A, 0xC3, 0xE9, 0xFA, 0x3D, 0x53,
43 0x96, 0x84, 0x6B, 0xBA, 0xF2, 0x63, 0x9A, 0x19,
44 0x7C, 0xAE, 0xE5, 0xF5, 0xF7, 0x16, 0x6A, 0xA2,
45 0x39, 0xB6, 0x7B, 0x0F, 0xC1, 0x93, 0x81, 0x1B,
46 0xEE, 0xB4, 0x1A, 0xEA, 0xD0, 0x91, 0x2F, 0xB8,
47 0x55, 0xB9, 0xDA, 0x85, 0x3F, 0x41, 0xBF, 0xE0,
48 0x5A, 0x58, 0x80, 0x5F, 0x66, 0x0B, 0xD8, 0x90,
49 0x35, 0xD5, 0xC0, 0xA7, 0x33, 0x06, 0x65, 0x69,
50 0x45, 0x00, 0x94, 0x56, 0x6D, 0x98, 0x9B, 0x76,
51 0x97, 0xFC, 0xB2, 0xC2, 0xB0, 0xFE, 0xDB, 0x20,
52 0xE1, 0xEB, 0xD6, 0xE4, 0xDD, 0x47, 0x4A, 0x1D,
53 0x42, 0xED, 0x9E, 0x6E, 0x49, 0x3C, 0xCD, 0x43,
54 0x27, 0xD2, 0x07, 0xD4, 0xDE, 0xC7, 0x67, 0x18,
55 0x89, 0xCB, 0x30, 0x1F, 0x8D, 0xC6, 0x8F, 0xAA,
56 0xC8, 0x74, 0xDC, 0xC9, 0x5D, 0x5C, 0x31, 0xA4,
57 0x70, 0x88, 0x61, 0x2C, 0x9F, 0x0D, 0x2B, 0x87,
58 0x50, 0x82, 0x54, 0x64, 0x26, 0x7D, 0x03, 0x40,
59 0x34, 0x4B, 0x1C, 0x73, 0xD1, 0xC4, 0xFD, 0x3B,
60 0xCC, 0xFB, 0x7F, 0xAB, 0xE6, 0x3E, 0x5B, 0xA5,
61 0xAD, 0x04, 0x23, 0x9C, 0x14, 0x51, 0x22, 0xF0,
62 0x29, 0x79, 0x71, 0x7E, 0xFF, 0x8C, 0x0E, 0xE2,
63 0x0C, 0xEF, 0xBC, 0x72, 0x75, 0x6F, 0x37, 0xA1,
64 0xEC, 0xD3, 0x8E, 0x62, 0x8B, 0x86, 0x10, 0xE8,
65 0x08, 0x77, 0x11, 0xBE, 0x92, 0x4F, 0x24, 0xC5,
66 0x32, 0x36, 0x9D, 0xCF, 0xF3, 0xA6, 0xBB, 0xAC,
67 0x5E, 0x6C, 0xA9, 0x13, 0x57, 0x25, 0xB5, 0xE3,
68 0xBD, 0xA8, 0x3A, 0x01, 0x05, 0x59, 0x2A, 0x46
72 static const uint8_t plus1mod10
[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};
75 static const uint8_t minus1mod10
[10] = {9, 0, 1, 2, 3, 4, 5, 6, 7, 8};
77 static inline uint16_t F
90 hi
^= S
[lo
^ k
[*i
]]; *i
= plus1mod10
[*i
];
91 lo
^= S
[hi
^ k
[*i
]]; *i
= plus1mod10
[*i
];
92 hi
^= S
[lo
^ k
[*i
]]; *i
= plus1mod10
[*i
];
93 lo
^= S
[hi
^ k
[*i
]]; *i
= plus1mod10
[*i
];
95 return ((uint16_t)hi
<< 8) | (uint16_t)lo
;
98 static inline uint16_t invF
111 *i
= minus1mod10
[*i
]; lo
^= S
[hi
^ k
[*i
]];
112 *i
= minus1mod10
[*i
]; hi
^= S
[lo
^ k
[*i
]];
113 *i
= minus1mod10
[*i
]; lo
^= S
[hi
^ k
[*i
]];
114 *i
= minus1mod10
[*i
]; hi
^= S
[lo
^ k
[*i
]];
116 return ((uint16_t)hi
<< 8) | (uint16_t)lo
;
119 static void skipjack_encrypt(const kripto_block
*s
, const void *pt
, void *ct
)
131 x0
= LOAD16B(CU8(pt
));
132 x1
= LOAD16B(CU8(pt
) + 2);
133 x2
= LOAD16B(CU8(pt
) + 4);
134 x3
= LOAD16B(CU8(pt
) + 6);
139 t0
= F(x0
, s
->k
, &i
);
149 t0
= F(x0
, s
->k
, &i
);
160 t0
= F(x0
, s
->k
, &i
);
170 t0
= F(x0
, s
->k
, &i
);
178 STORE16B(x0
, U8(ct
));
179 STORE16B(x1
, U8(ct
) + 2);
180 STORE16B(x2
, U8(ct
) + 4);
181 STORE16B(x3
, U8(ct
) + 6);
184 static void skipjack_decrypt(const kripto_block
*s
, const void *ct
, void *pt
)
193 uint8_t i
= 8; /* (r * 4) % 10 */
195 x0
= LOAD16B(CU8(ct
));
196 x1
= LOAD16B(CU8(ct
) + 2);
197 x2
= LOAD16B(CU8(ct
) + 4);
198 x3
= LOAD16B(CU8(ct
) + 6);
203 t
= invF(x1
, s
->k
, &i
);
214 x0
= invF(x1
, s
->k
, &i
);
223 t
= invF(x1
, s
->k
, &i
);
234 x0
= invF(x1
, s
->k
, &i
);
240 STORE16B(x0
, U8(pt
));
241 STORE16B(x1
, U8(pt
) + 2);
242 STORE16B(x2
, U8(pt
) + 4);
243 STORE16B(x3
, U8(pt
) + 6);
246 static kripto_block
*skipjack_recreate
256 memcpy(s
->k
, key
, key_len
);
258 if(key_len
< 10) memset(s
->k
+ key_len
, 0, 10 - key_len
);
263 static kripto_block
*skipjack_create
272 s
= malloc(sizeof(kripto_block
));
275 s
->obj
.desc
= kripto_block_skipjack
;
277 skipjack_recreate(s
, r
, key
, key_len
);
282 static void skipjack_destroy(kripto_block
*s
)
284 kripto_memwipe(s
, sizeof(kripto_block
));
288 static const kripto_block_desc skipjack
=
301 const kripto_block_desc
*const kripto_block_skipjack
= &skipjack
;