diff options
author | Matt Johnston <matt@ucc.asn.au> | 2007-02-03 08:20:34 +0000 |
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committer | Matt Johnston <matt@ucc.asn.au> | 2007-02-03 08:20:34 +0000 |
commit | d9aeb2773e236e662c8b493f4bcee978f9908d7c (patch) | |
tree | bac48e388bf3ac739ae14cdf98da0eb4bb9d17bf /libtomcrypt/src/ciphers/skipjack.c | |
parent | 056b92bd4c8a42ce1843493310d382159166edb8 (diff) | |
parent | c5fd7dd5548f28e32d846e39d17e5c4de4e769af (diff) |
merge of '5fdf69ca60d1683cdd9f4c2595134bed26394834'
and '6b61c50f4cf888bea302ac8fcf5dbb573b443251'
--HG--
extra : convert_revision : b1dd3b94e60a07a176dba2b035ac79968595990a
Diffstat (limited to 'libtomcrypt/src/ciphers/skipjack.c')
-rw-r--r-- | libtomcrypt/src/ciphers/skipjack.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/libtomcrypt/src/ciphers/skipjack.c b/libtomcrypt/src/ciphers/skipjack.c new file mode 100644 index 0000000..3e0b576 --- /dev/null +++ b/libtomcrypt/src/ciphers/skipjack.c @@ -0,0 +1,343 @@ +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com + */ + +/** + @file skipjack.c + Skipjack Implementation by Tom St Denis +*/ +#include "tomcrypt.h" + +#ifdef SKIPJACK + +const struct ltc_cipher_descriptor skipjack_desc = +{ + "skipjack", + 17, + 10, 10, 8, 32, + &skipjack_setup, + &skipjack_ecb_encrypt, + &skipjack_ecb_decrypt, + &skipjack_test, + &skipjack_done, + &skipjack_keysize, + NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL +}; + +static const unsigned char sbox[256] = { + 0xa3,0xd7,0x09,0x83,0xf8,0x48,0xf6,0xf4,0xb3,0x21,0x15,0x78,0x99,0xb1,0xaf,0xf9, + 0xe7,0x2d,0x4d,0x8a,0xce,0x4c,0xca,0x2e,0x52,0x95,0xd9,0x1e,0x4e,0x38,0x44,0x28, + 0x0a,0xdf,0x02,0xa0,0x17,0xf1,0x60,0x68,0x12,0xb7,0x7a,0xc3,0xe9,0xfa,0x3d,0x53, + 0x96,0x84,0x6b,0xba,0xf2,0x63,0x9a,0x19,0x7c,0xae,0xe5,0xf5,0xf7,0x16,0x6a,0xa2, + 0x39,0xb6,0x7b,0x0f,0xc1,0x93,0x81,0x1b,0xee,0xb4,0x1a,0xea,0xd0,0x91,0x2f,0xb8, + 0x55,0xb9,0xda,0x85,0x3f,0x41,0xbf,0xe0,0x5a,0x58,0x80,0x5f,0x66,0x0b,0xd8,0x90, + 0x35,0xd5,0xc0,0xa7,0x33,0x06,0x65,0x69,0x45,0x00,0x94,0x56,0x6d,0x98,0x9b,0x76, + 0x97,0xfc,0xb2,0xc2,0xb0,0xfe,0xdb,0x20,0xe1,0xeb,0xd6,0xe4,0xdd,0x47,0x4a,0x1d, + 0x42,0xed,0x9e,0x6e,0x49,0x3c,0xcd,0x43,0x27,0xd2,0x07,0xd4,0xde,0xc7,0x67,0x18, + 0x89,0xcb,0x30,0x1f,0x8d,0xc6,0x8f,0xaa,0xc8,0x74,0xdc,0xc9,0x5d,0x5c,0x31,0xa4, + 0x70,0x88,0x61,0x2c,0x9f,0x0d,0x2b,0x87,0x50,0x82,0x54,0x64,0x26,0x7d,0x03,0x40, + 0x34,0x4b,0x1c,0x73,0xd1,0xc4,0xfd,0x3b,0xcc,0xfb,0x7f,0xab,0xe6,0x3e,0x5b,0xa5, + 0xad,0x04,0x23,0x9c,0x14,0x51,0x22,0xf0,0x29,0x79,0x71,0x7e,0xff,0x8c,0x0e,0xe2, + 0x0c,0xef,0xbc,0x72,0x75,0x6f,0x37,0xa1,0xec,0xd3,0x8e,0x62,0x8b,0x86,0x10,0xe8, + 0x08,0x77,0x11,0xbe,0x92,0x4f,0x24,0xc5,0x32,0x36,0x9d,0xcf,0xf3,0xa6,0xbb,0xac, + 0x5e,0x6c,0xa9,0x13,0x57,0x25,0xb5,0xe3,0xbd,0xa8,0x3a,0x01,0x05,0x59,0x2a,0x46 +}; + +/* simple x + 1 (mod 10) in one step. */ +static const int keystep[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 }; + +/* simple x - 1 (mod 10) in one step */ +static const int ikeystep[] = { 9, 0, 1, 2, 3, 4, 5, 6, 7, 8 }; + + /** + Initialize the Skipjack block cipher + @param key The symmetric key you wish to pass + @param keylen The key length in bytes + @param num_rounds The number of rounds desired (0 for default) + @param skey The key in as scheduled by this function. + @return CRYPT_OK if successful + */ +int skipjack_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) +{ + int x; + + LTC_ARGCHK(key != NULL); + LTC_ARGCHK(skey != NULL); + + if (keylen != 10) { + return CRYPT_INVALID_KEYSIZE; + } + + if (num_rounds != 32 && num_rounds != 0) { + return CRYPT_INVALID_ROUNDS; + } + + /* make sure the key is in range for platforms where CHAR_BIT != 8 */ + for (x = 0; x < 10; x++) { + skey->skipjack.key[x] = key[x] & 255; + } + + return CRYPT_OK; +} + +#define RULE_A \ + tmp = g_func(w1, &kp, skey->skipjack.key); \ + w1 = tmp ^ w4 ^ x; \ + w4 = w3; w3 = w2; \ + w2 = tmp; + +#define RULE_B \ + tmp = g_func(w1, &kp, skey->skipjack.key); \ + tmp1 = w4; w4 = w3; \ + w3 = w1 ^ w2 ^ x; \ + w1 = tmp1; w2 = tmp; + +#define RULE_A1 \ + tmp = w1 ^ w2 ^ x; \ + w1 = ig_func(w2, &kp, skey->skipjack.key); \ + w2 = w3; w3 = w4; w4 = tmp; + +#define RULE_B1 \ + tmp = ig_func(w2, &kp, skey->skipjack.key); \ + w2 = tmp ^ w3 ^ x; \ + w3 = w4; w4 = w1; w1 = tmp; + +static unsigned g_func(unsigned w, int *kp, unsigned char *key) +{ + unsigned char g1,g2; + + g1 = (w >> 8) & 255; g2 = w & 255; + g1 ^= sbox[g2^key[*kp]]; *kp = keystep[*kp]; + g2 ^= sbox[g1^key[*kp]]; *kp = keystep[*kp]; + g1 ^= sbox[g2^key[*kp]]; *kp = keystep[*kp]; + g2 ^= sbox[g1^key[*kp]]; *kp = keystep[*kp]; + return ((unsigned)g1<<8)|(unsigned)g2; +} + +static unsigned ig_func(unsigned w, int *kp, unsigned char *key) +{ + unsigned char g1,g2; + + g1 = (w >> 8) & 255; g2 = w & 255; + *kp = ikeystep[*kp]; g2 ^= sbox[g1^key[*kp]]; + *kp = ikeystep[*kp]; g1 ^= sbox[g2^key[*kp]]; + *kp = ikeystep[*kp]; g2 ^= sbox[g1^key[*kp]]; + *kp = ikeystep[*kp]; g1 ^= sbox[g2^key[*kp]]; + return ((unsigned)g1<<8)|(unsigned)g2; +} + +/** + Encrypts a block of text with Skipjack + @param pt The input plaintext (8 bytes) + @param ct The output ciphertext (8 bytes) + @param skey The key as scheduled + @return CRYPT_OK if successful +*/ +#ifdef LTC_CLEAN_STACK +static int _skipjack_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) +#else +int skipjack_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) +#endif +{ + unsigned w1,w2,w3,w4,tmp,tmp1; + int x, kp; + + LTC_ARGCHK(pt != NULL); + LTC_ARGCHK(ct != NULL); + LTC_ARGCHK(skey != NULL); + + /* load block */ + w1 = ((unsigned)pt[0]<<8)|pt[1]; + w2 = ((unsigned)pt[2]<<8)|pt[3]; + w3 = ((unsigned)pt[4]<<8)|pt[5]; + w4 = ((unsigned)pt[6]<<8)|pt[7]; + + /* 8 rounds of RULE A */ + for (x = 1, kp = 0; x < 9; x++) { + RULE_A; + } + + /* 8 rounds of RULE B */ + for (; x < 17; x++) { + RULE_B; + } + + /* 8 rounds of RULE A */ + for (; x < 25; x++) { + RULE_A; + } + + /* 8 rounds of RULE B */ + for (; x < 33; x++) { + RULE_B; + } + + /* store block */ + ct[0] = (w1>>8)&255; ct[1] = w1&255; + ct[2] = (w2>>8)&255; ct[3] = w2&255; + ct[4] = (w3>>8)&255; ct[5] = w3&255; + ct[6] = (w4>>8)&255; ct[7] = w4&255; + + return CRYPT_OK; +} + +#ifdef LTC_CLEAN_STACK +int skipjack_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) +{ + int err = _skipjack_ecb_encrypt(pt, ct, skey); + burn_stack(sizeof(unsigned) * 8 + sizeof(int) * 2); + return err; +} +#endif + +/** + Decrypts a block of text with Skipjack + @param ct The input ciphertext (8 bytes) + @param pt The output plaintext (8 bytes) + @param skey The key as scheduled + @return CRYPT_OK if successful +*/ +#ifdef LTC_CLEAN_STACK +static int _skipjack_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) +#else +int skipjack_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) +#endif +{ + unsigned w1,w2,w3,w4,tmp; + int x, kp; + + LTC_ARGCHK(pt != NULL); + LTC_ARGCHK(ct != NULL); + LTC_ARGCHK(skey != NULL); + + /* load block */ + w1 = ((unsigned)ct[0]<<8)|ct[1]; + w2 = ((unsigned)ct[2]<<8)|ct[3]; + w3 = ((unsigned)ct[4]<<8)|ct[5]; + w4 = ((unsigned)ct[6]<<8)|ct[7]; + + /* 8 rounds of RULE B^-1 + + Note the value "kp = 8" comes from "kp = (32 * 4) mod 10" where 32*4 is 128 which mod 10 is 8 + */ + for (x = 32, kp = 8; x > 24; x--) { + RULE_B1; + } + + /* 8 rounds of RULE A^-1 */ + for (; x > 16; x--) { + RULE_A1; + } + + + /* 8 rounds of RULE B^-1 */ + for (; x > 8; x--) { + RULE_B1; + } + + /* 8 rounds of RULE A^-1 */ + for (; x > 0; x--) { + RULE_A1; + } + + /* store block */ + pt[0] = (w1>>8)&255; pt[1] = w1&255; + pt[2] = (w2>>8)&255; pt[3] = w2&255; + pt[4] = (w3>>8)&255; pt[5] = w3&255; + pt[6] = (w4>>8)&255; pt[7] = w4&255; + + return CRYPT_OK; +} + +#ifdef LTC_CLEAN_STACK +int skipjack_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) +{ + int err = _skipjack_ecb_decrypt(ct, pt, skey); + burn_stack(sizeof(unsigned) * 7 + sizeof(int) * 2); + return err; +} +#endif + +/** + Performs a self-test of the Skipjack block cipher + @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled +*/ +int skipjack_test(void) +{ + #ifndef LTC_TEST + return CRYPT_NOP; + #else + static const struct { + unsigned char key[10], pt[8], ct[8]; + } tests[] = { + { + { 0x00, 0x99, 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }, + { 0x33, 0x22, 0x11, 0x00, 0xdd, 0xcc, 0xbb, 0xaa }, + { 0x25, 0x87, 0xca, 0xe2, 0x7a, 0x12, 0xd3, 0x00 } + } + }; + unsigned char buf[2][8]; + int x, y, err; + symmetric_key key; + + for (x = 0; x < (int)(sizeof(tests) / sizeof(tests[0])); x++) { + /* setup key */ + if ((err = skipjack_setup(tests[x].key, 10, 0, &key)) != CRYPT_OK) { + return err; + } + + /* encrypt and decrypt */ + skipjack_ecb_encrypt(tests[x].pt, buf[0], &key); + skipjack_ecb_decrypt(buf[0], buf[1], &key); + + /* compare */ + if (XMEMCMP(buf[0], tests[x].ct, 8) != 0 || XMEMCMP(buf[1], tests[x].pt, 8) != 0) { + return CRYPT_FAIL_TESTVECTOR; + } + + /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */ + for (y = 0; y < 8; y++) buf[0][y] = 0; + for (y = 0; y < 1000; y++) skipjack_ecb_encrypt(buf[0], buf[0], &key); + for (y = 0; y < 1000; y++) skipjack_ecb_decrypt(buf[0], buf[0], &key); + for (y = 0; y < 8; y++) if (buf[0][y] != 0) return CRYPT_FAIL_TESTVECTOR; + } + + return CRYPT_OK; + #endif +} + +/** Terminate the context + @param skey The scheduled key +*/ +void skipjack_done(symmetric_key *skey) +{ +} + +/** + Gets suitable key size + @param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable. + @return CRYPT_OK if the input key size is acceptable. +*/ +int skipjack_keysize(int *keysize) +{ + LTC_ARGCHK(keysize != NULL); + if (*keysize < 10) { + return CRYPT_INVALID_KEYSIZE; + } else if (*keysize > 10) { + *keysize = 10; + } + return CRYPT_OK; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/ciphers/skipjack.c,v $ */ +/* $Revision: 1.12 $ */ +/* $Date: 2006/11/08 23:01:06 $ */ |