/* * Optimized implementation of SKIPJACK algorithm * * originally written by Panu Rissanen 1998.06.24 * optimized by Mark Tillotson 1998.06.25 * optimized by Paulo Barreto 1998.06.30 * gnupg support by Werner Koch 1998.07.02 */ /* How to compile: * gcc -Wall -O2 -shared -fPIC -o skipjack skipjack.c */ #include #include #include /* configuration stuff */ #ifdef __alpha__ #define SIZEOF_UNSIGNED_LONG 8 #else #define SIZEOF_UNSIGNED_LONG 4 #endif #if defined(__mc68000__) || defined (__sparc__) || defined (__PPC__) \ || (defined(__mips__) && (defined(MIPSEB) || defined (__MIPSEB__)) ) #define BIG_ENDIAN_HOST 1 #else #define LITTLE_ENDIAN_HOST 1 #endif typedef unsigned long ulong; typedef unsigned short ushort; typedef unsigned char byte; typedef unsigned short u16; #if SIZEOF_UNSIGNED_LONG == 4 typedef unsigned long u32; typedef unsigned long word32; #else typedef unsigned int u32; typedef unsigned int word32; #endif /* end configurable stuff */ #ifndef DIM #define DIM(v) (sizeof(v)/sizeof((v)[0])) #define DIMof(type,member) DIM(((type *)0)->member) #endif /* imports */ void g10_log_fatal( const char *fmt, ... ); #define FNCCAST_SETKEY(f) ((void(*)(void*, byte*, unsigned))(f)) #define FNCCAST_CRYPT(f) ((void(*)(void*, byte*, byte*))(f)) typedef struct { byte tab[10][256]; } SJ_context; static void selftest(void); /** * The F-table byte permutation (see description of the G-box permutation) */ static const byte fTable[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 }; /** * The key-dependent permutation G on V^16 is a four-round Feistel network. * The round function is a fixed byte-substitution table (permutation on V^8), * the F-table. Each round of G incorporates a single byte from the key. */ #define g(tab, w, i, j, k, l) \ { \ w ^= (word32)tab[i][w & 0xff] << 8; \ w ^= (word32)tab[j][w >> 8]; \ w ^= (word32)tab[k][w & 0xff] << 8; \ w ^= (word32)tab[l][w >> 8]; \ } #define g0(tab, w) g(tab, w, 0, 1, 2, 3) #define g1(tab, w) g(tab, w, 4, 5, 6, 7) #define g2(tab, w) g(tab, w, 8, 9, 0, 1) #define g3(tab, w) g(tab, w, 2, 3, 4, 5) #define g4(tab, w) g(tab, w, 6, 7, 8, 9) /** * The inverse of the G permutation. */ #define h(tab, w, i, j, k, l) \ { \ w ^= (word32)tab[l][w >> 8]; \ w ^= (word32)tab[k][w & 0xff] << 8; \ w ^= (word32)tab[j][w >> 8]; \ w ^= (word32)tab[i][w & 0xff] << 8; \ } #define h0(tab, w) h(tab, w, 0, 1, 2, 3) #define h1(tab, w) h(tab, w, 4, 5, 6, 7) #define h2(tab, w) h(tab, w, 8, 9, 0, 1) #define h3(tab, w) h(tab, w, 2, 3, 4, 5) #define h4(tab, w) h(tab, w, 6, 7, 8, 9) /** * Preprocess a user key into a table to save an XOR at each F-table access. */ static void makeKey( SJ_context *ctx, byte *key, unsigned keylen ) { int i; static int initialized; if( !initialized ) { initialized = 1; selftest(); } assert(keylen == 10); /* tab[i][c] = fTable[c ^ key[i]] */ for (i = 0; i < 10; i++) { byte *t = ctx->tab[i], k = key[i]; int c; for (c = 0; c < 256; c++) { t[c] = fTable[c ^ k]; } } } /** * Encrypt a single block of data. */ static void encrypt_block( SJ_context *ctx, byte *out, byte *in ) { word32 w1, w2, w3, w4; w1 = (in[0] << 8) + in[1]; w2 = (in[2] << 8) + in[3]; w3 = (in[4] << 8) + in[5]; w4 = (in[6] << 8) + in[7]; /* stepping rule A: */ g0((ctx->tab), w1); w4 ^= w1 ^ 1; g1((ctx->tab), w4); w3 ^= w4 ^ 2; g2((ctx->tab), w3); w2 ^= w3 ^ 3; g3((ctx->tab), w2); w1 ^= w2 ^ 4; g4((ctx->tab), w1); w4 ^= w1 ^ 5; g0((ctx->tab), w4); w3 ^= w4 ^ 6; g1((ctx->tab), w3); w2 ^= w3 ^ 7; g2((ctx->tab), w2); w1 ^= w2 ^ 8; /* stepping rule B: */ w2 ^= w1 ^ 9; g3((ctx->tab), w1); w1 ^= w4 ^ 10; g4((ctx->tab), w4); w4 ^= w3 ^ 11; g0((ctx->tab), w3); w3 ^= w2 ^ 12; g1((ctx->tab), w2); w2 ^= w1 ^ 13; g2((ctx->tab), w1); w1 ^= w4 ^ 14; g3((ctx->tab), w4); w4 ^= w3 ^ 15; g4((ctx->tab), w3); w3 ^= w2 ^ 16; g0((ctx->tab), w2); /* stepping rule A: */ g1((ctx->tab), w1); w4 ^= w1 ^ 17; g2((ctx->tab), w4); w3 ^= w4 ^ 18; g3((ctx->tab), w3); w2 ^= w3 ^ 19; g4((ctx->tab), w2); w1 ^= w2 ^ 20; g0((ctx->tab), w1); w4 ^= w1 ^ 21; g1((ctx->tab), w4); w3 ^= w4 ^ 22; g2((ctx->tab), w3); w2 ^= w3 ^ 23; g3((ctx->tab), w2); w1 ^= w2 ^ 24; /* stepping rule B: */ w2 ^= w1 ^ 25; g4((ctx->tab), w1); w1 ^= w4 ^ 26; g0((ctx->tab), w4); w4 ^= w3 ^ 27; g1((ctx->tab), w3); w3 ^= w2 ^ 28; g2((ctx->tab), w2); w2 ^= w1 ^ 29; g3((ctx->tab), w1); w1 ^= w4 ^ 30; g4((ctx->tab), w4); w4 ^= w3 ^ 31; g0((ctx->tab), w3); w3 ^= w2 ^ 32; g1((ctx->tab), w2); out[0] = (byte)(w1 >> 8); out[1] = (byte)w1; out[2] = (byte)(w2 >> 8); out[3] = (byte)w2; out[4] = (byte)(w3 >> 8); out[5] = (byte)w3; out[6] = (byte)(w4 >> 8); out[7] = (byte)w4; } /** * Decrypt a single block of data. */ static void decrypt_block( SJ_context *ctx, byte *out, byte *in) { word32 w1, w2, w3, w4; w1 = (in[0] << 8) + in[1]; w2 = (in[2] << 8) + in[3]; w3 = (in[4] << 8) + in[5]; w4 = (in[6] << 8) + in[7]; /* stepping rule A: */ h1((ctx->tab), w2); w3 ^= w2 ^ 32; h0((ctx->tab), w3); w4 ^= w3 ^ 31; h4((ctx->tab), w4); w1 ^= w4 ^ 30; h3((ctx->tab), w1); w2 ^= w1 ^ 29; h2((ctx->tab), w2); w3 ^= w2 ^ 28; h1((ctx->tab), w3); w4 ^= w3 ^ 27; h0((ctx->tab), w4); w1 ^= w4 ^ 26; h4((ctx->tab), w1); w2 ^= w1 ^ 25; /* stepping rule B: */ w1 ^= w2 ^ 24; h3((ctx->tab), w2); w2 ^= w3 ^ 23; h2((ctx->tab), w3); w3 ^= w4 ^ 22; h1((ctx->tab), w4); w4 ^= w1 ^ 21; h0((ctx->tab), w1); w1 ^= w2 ^ 20; h4((ctx->tab), w2); w2 ^= w3 ^ 19; h3((ctx->tab), w3); w3 ^= w4 ^ 18; h2((ctx->tab), w4); w4 ^= w1 ^ 17; h1((ctx->tab), w1); /* stepping rule A: */ h0((ctx->tab), w2); w3 ^= w2 ^ 16; h4((ctx->tab), w3); w4 ^= w3 ^ 15; h3((ctx->tab), w4); w1 ^= w4 ^ 14; h2((ctx->tab), w1); w2 ^= w1 ^ 13; h1((ctx->tab), w2); w3 ^= w2 ^ 12; h0((ctx->tab), w3); w4 ^= w3 ^ 11; h4((ctx->tab), w4); w1 ^= w4 ^ 10; h3((ctx->tab), w1); w2 ^= w1 ^ 9; /* stepping rule B: */ w1 ^= w2 ^ 8; h2((ctx->tab), w2); w2 ^= w3 ^ 7; h1((ctx->tab), w3); w3 ^= w4 ^ 6; h0((ctx->tab), w4); w4 ^= w1 ^ 5; h4((ctx->tab), w1); w1 ^= w2 ^ 4; h3((ctx->tab), w2); w2 ^= w3 ^ 3; h2((ctx->tab), w3); w3 ^= w4 ^ 2; h1((ctx->tab), w4); w4 ^= w1 ^ 1; h0((ctx->tab), w1); out[0] = (byte)(w1 >> 8); out[1] = (byte)w1; out[2] = (byte)(w2 >> 8); out[3] = (byte)w2; out[4] = (byte)(w3 >> 8); out[5] = (byte)w3; out[6] = (byte)(w4 >> 8); out[7] = (byte)w4; } static void selftest() { SJ_context c; byte inp[8] = { 0x33, 0x22, 0x11, 0x00, 0xdd, 0xcc, 0xbb, 0xaa }; byte key[10] = { 0x00, 0x99, 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; byte enc[8], dec[8]; byte chk[8] = { 0x25, 0x87, 0xca, 0xe2, 0x7a, 0x12, 0xd3, 0x00 }; makeKey( &c, key, 10 ); encrypt_block( &c, enc, inp); if( memcmp( enc, chk, 8 ) ) g10_log_fatal("Skipjack test encryption failed\n"); decrypt_block( &c, dec, enc); if( memcmp( dec, inp, 8 ) ) g10_log_fatal("Skipjack test decryption failed\n"); } #ifdef TEST #include #include #include int main() { byte inp[8] = { 0x33, 0x22, 0x11, 0x00, 0xdd, 0xcc, 0xbb, 0xaa }; byte key[10] = { 0x00, 0x99, 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 }; byte enc[8], dec[8]; byte chk[8] = { 0x25, 0x87, 0xca, 0xe2, 0x7a, 0x12, 0xd3, 0x00 }; byte tab[10][256]; int i; clock_t elapsed; makeKey(key, tab); encrypt(tab, inp, enc); printf((memcmp(enc, chk, 8) == 0) ? "encryption OK!\n" : "encryption failure!\n"); decrypt(tab, enc, dec); printf((memcmp(dec, inp, 8) == 0) ? "decryption OK!\n" : "decryption failure!\n"); elapsed = -clock(); for (i = 0; i < 1000000; i++) { encrypt(tab, inp, enc); } elapsed += clock(); printf ("elapsed time: %.1f s.\n", (float)elapsed/CLOCKS_PER_SEC); return 0; } #endif /*TEST*/ /**************** * Return some information about the algorithm. We need algo here to * distinguish different flavors of the algorithm. * Returns: A pointer to string describing the algorithm or NULL if * the ALGO is invalid. */ const char * skipjack_get_info( int algo, size_t *keylen, size_t *blocksize, size_t *contextsize, void (**r_setkey)( void *c, byte *key, unsigned keylen ), void (**r_encrypt)( void *c, byte *outbuf, byte *inbuf ), void (**r_decrypt)( void *c, byte *outbuf, byte *inbuf ) ) { *keylen = 80; *blocksize = 8; *contextsize = sizeof(SJ_context); *r_setkey = FNCCAST_SETKEY(makeKey); *r_encrypt= FNCCAST_CRYPT(encrypt_block); *r_decrypt= FNCCAST_CRYPT(decrypt_block); if( algo == 101 ) return "SKIPJACK"; return NULL; } const char * const gnupgext_version = "Skipjack ($Revision: 1.1 $)"; static struct { int class; int version; int value; void (*func)(void); } func_table[] = { { 20, 1, 0, (void(*)(void))skipjack_get_info }, { 21, 1, 101 }, }; void * gnupgext_enum_func( int what, int *sequence, int *class, int *vers ) { void *ret; int i = *sequence; do { if( i >= DIM(func_table) || i < 0 ) { return NULL; } *class = func_table[i].class; *vers = func_table[i].version; switch( *class ) { case 11: case 21: case 31: ret = &func_table[i].value; break; default: ret = func_table[i].func; break; } i++; } while( what && what != *class ); *sequence = i; return ret; }