diff options
Diffstat (limited to 'src/block/skipjack/skipjack.cpp')
| -rw-r--r-- | src/block/skipjack/skipjack.cpp | 175 |
1 files changed, 98 insertions, 77 deletions
diff --git a/src/block/skipjack/skipjack.cpp b/src/block/skipjack/skipjack.cpp index e8b2cfb8d..b23d1e160 100644 --- a/src/block/skipjack/skipjack.cpp +++ b/src/block/skipjack/skipjack.cpp @@ -10,6 +10,68 @@ namespace Botan { +namespace { + +/* +* Skipjack Stepping Rule 'A' +*/ +void step_A(u16bit& W1, u16bit& W4, u32bit round, const byte FTAB[]) + { + byte G1 = get_byte(0, W1), G2 = get_byte(1, W1), G3; + + G3 = FTAB[((4*round-4)%10)*256 + G2] ^ G1; + G1 = FTAB[((4*round-3)%10)*256 + G3] ^ G2; + G2 = FTAB[((4*round-2)%10)*256 + G1] ^ G3; + G3 = FTAB[((4*round-1)%10)*256 + G2] ^ G1; + + W1 = make_u16bit(G2, G3); + W4 ^= W1 ^ round; + } + +/* +* Skipjack Stepping Rule 'B' +*/ +void step_B(u16bit& W1, u16bit& W2, u32bit round, const byte FTAB[]) + { + W2 ^= W1 ^ round; + byte G1 = get_byte(0, W1), G2 = get_byte(1, W1), G3; + G3 = FTAB[((4*round-4)%10)*256 + G2] ^ G1; + G1 = FTAB[((4*round-3)%10)*256 + G3] ^ G2; + G2 = FTAB[((4*round-2)%10)*256 + G1] ^ G3; + G3 = FTAB[((4*round-1)%10)*256 + G2] ^ G1; + W1 = make_u16bit(G2, G3); + } + +/* +* Skipjack Invserse Stepping Rule 'A' +*/ +void step_Ai(u16bit& W1, u16bit& W2, u32bit round, const byte FTAB[]) + { + W1 ^= W2 ^ round; + byte G1 = get_byte(1, W2), G2 = get_byte(0, W2), G3; + G3 = FTAB[((4 * round - 1) % 10)*256 + G2] ^ G1; + G1 = FTAB[((4 * round - 2) % 10)*256 + G3] ^ G2; + G2 = FTAB[((4 * round - 3) % 10)*256 + G1] ^ G3; + G3 = FTAB[((4 * round - 4) % 10)*256 + G2] ^ G1; + W2 = make_u16bit(G3, G2); + } + +/* +* Skipjack Invserse Stepping Rule 'B' +*/ +void step_Bi(u16bit& W2, u16bit& W3, u32bit round, const byte FTAB[]) + { + byte G1 = get_byte(1, W2), G2 = get_byte(0, W2), G3; + G3 = FTAB[((4 * round - 1) % 10)*256 + G2] ^ G1; + G1 = FTAB[((4 * round - 2) % 10)*256 + G3] ^ G2; + G2 = FTAB[((4 * round - 3) % 10)*256 + G1] ^ G3; + G3 = FTAB[((4 * round - 4) % 10)*256 + G2] ^ G1; + W2 = make_u16bit(G3, G2); + W3 ^= W2 ^ round; + } + +} + /* * Skipjack Encryption */ @@ -22,17 +84,25 @@ void Skipjack::encrypt_n(const byte in[], byte out[], u32bit blocks) const u16bit W3 = load_le<u16bit>(in, 1); u16bit W4 = load_le<u16bit>(in, 0); - step_A(W1,W4, 1); step_A(W4,W3, 2); step_A(W3,W2, 3); step_A(W2,W1, 4); - step_A(W1,W4, 5); step_A(W4,W3, 6); step_A(W3,W2, 7); step_A(W2,W1, 8); + step_A(W1, W4, 1, FTAB); step_A(W4, W3, 2, FTAB); + step_A(W3, W2, 3, FTAB); step_A(W2, W1, 4, FTAB); + step_A(W1, W4, 5, FTAB); step_A(W4, W3, 6, FTAB); + step_A(W3, W2, 7, FTAB); step_A(W2, W1, 8, FTAB); - step_B(W1,W2, 9); step_B(W4,W1,10); step_B(W3,W4,11); step_B(W2,W3,12); - step_B(W1,W2,13); step_B(W4,W1,14); step_B(W3,W4,15); step_B(W2,W3,16); + step_B(W1, W2, 9, FTAB); step_B(W4, W1, 10, FTAB); + step_B(W3, W4, 11, FTAB); step_B(W2, W3, 12, FTAB); + step_B(W1, W2, 13, FTAB); step_B(W4, W1, 14, FTAB); + step_B(W3, W4, 15, FTAB); step_B(W2, W3, 16, FTAB); - step_A(W1,W4,17); step_A(W4,W3,18); step_A(W3,W2,19); step_A(W2,W1,20); - step_A(W1,W4,21); step_A(W4,W3,22); step_A(W3,W2,23); step_A(W2,W1,24); + step_A(W1, W4, 17, FTAB); step_A(W4, W3, 18, FTAB); + step_A(W3, W2, 19, FTAB); step_A(W2, W1, 20, FTAB); + step_A(W1, W4, 21, FTAB); step_A(W4, W3, 22, FTAB); + step_A(W3, W2, 23, FTAB); step_A(W2, W1, 24, FTAB); - step_B(W1,W2,25); step_B(W4,W1,26); step_B(W3,W4,27); step_B(W2,W3,28); - step_B(W1,W2,29); step_B(W4,W1,30); step_B(W3,W4,31); step_B(W2,W3,32); + step_B(W1, W2, 25, FTAB); step_B(W4, W1, 26, FTAB); + step_B(W3, W4, 27, FTAB); step_B(W2, W3, 28, FTAB); + step_B(W1, W2, 29, FTAB); step_B(W4, W1, 30, FTAB); + step_B(W3, W4, 31, FTAB); step_B(W2, W3, 32, FTAB); store_le(out, W4, W3, W2, W1); @@ -53,17 +123,25 @@ void Skipjack::decrypt_n(const byte in[], byte out[], u32bit blocks) const u16bit W3 = load_le<u16bit>(in, 1); u16bit W4 = load_le<u16bit>(in, 0); - step_Bi(W2,W3,32); step_Bi(W3,W4,31); step_Bi(W4,W1,30); step_Bi(W1,W2,29); - step_Bi(W2,W3,28); step_Bi(W3,W4,27); step_Bi(W4,W1,26); step_Bi(W1,W2,25); + step_Bi(W2, W3, 32, FTAB); step_Bi(W3, W4, 31, FTAB); + step_Bi(W4, W1, 30, FTAB); step_Bi(W1, W2, 29, FTAB); + step_Bi(W2, W3, 28, FTAB); step_Bi(W3, W4, 27, FTAB); + step_Bi(W4, W1, 26, FTAB); step_Bi(W1, W2, 25, FTAB); - step_Ai(W1,W2,24); step_Ai(W2,W3,23); step_Ai(W3,W4,22); step_Ai(W4,W1,21); - step_Ai(W1,W2,20); step_Ai(W2,W3,19); step_Ai(W3,W4,18); step_Ai(W4,W1,17); + step_Ai(W1, W2, 24, FTAB); step_Ai(W2, W3, 23, FTAB); + step_Ai(W3, W4, 22, FTAB); step_Ai(W4, W1, 21, FTAB); + step_Ai(W1, W2, 20, FTAB); step_Ai(W2, W3, 19, FTAB); + step_Ai(W3, W4, 18, FTAB); step_Ai(W4, W1, 17, FTAB); - step_Bi(W2,W3,16); step_Bi(W3,W4,15); step_Bi(W4,W1,14); step_Bi(W1,W2,13); - step_Bi(W2,W3,12); step_Bi(W3,W4,11); step_Bi(W4,W1,10); step_Bi(W1,W2, 9); + step_Bi(W2, W3, 16, FTAB); step_Bi(W3, W4, 15, FTAB); + step_Bi(W4, W1, 14, FTAB); step_Bi(W1, W2, 13, FTAB); + step_Bi(W2, W3, 12, FTAB); step_Bi(W3, W4, 11, FTAB); + step_Bi(W4, W1, 10, FTAB); step_Bi(W1, W2, 9, FTAB); - step_Ai(W1,W2, 8); step_Ai(W2,W3, 7); step_Ai(W3,W4, 6); step_Ai(W4,W1, 5); - step_Ai(W1,W2, 4); step_Ai(W2,W3, 3); step_Ai(W3,W4, 2); step_Ai(W4,W1, 1); + step_Ai(W1, W2, 8, FTAB); step_Ai(W2, W3, 7, FTAB); + step_Ai(W3, W4, 6, FTAB); step_Ai(W4, W1, 5, FTAB); + step_Ai(W1, W2, 4, FTAB); step_Ai(W2, W3, 3, FTAB); + step_Ai(W3, W4, 2, FTAB); step_Ai(W4, W1, 1, FTAB); store_le(out, W4, W3, W2, W1); @@ -73,62 +151,6 @@ void Skipjack::decrypt_n(const byte in[], byte out[], u32bit blocks) const } /* -* Skipjack Stepping Rule 'A' -*/ -void Skipjack::step_A(u16bit& W1, u16bit& W4, u32bit round) const - { - byte G1 = get_byte(0, W1), G2 = get_byte(1, W1), G3; - G3 = FTABLE[(4 * round - 4) % 10][G2] ^ G1; - G1 = FTABLE[(4 * round - 3) % 10][G3] ^ G2; - G2 = FTABLE[(4 * round - 2) % 10][G1] ^ G3; - G3 = FTABLE[(4 * round - 1) % 10][G2] ^ G1; - W1 = make_u16bit(G2, G3); - W4 ^= W1 ^ round; - } - -/* -* Skipjack Stepping Rule 'B' -*/ -void Skipjack::step_B(u16bit& W1, u16bit& W2, u32bit round) const - { - W2 ^= W1 ^ round; - byte G1 = get_byte(0, W1), G2 = get_byte(1, W1), G3; - G3 = FTABLE[(4 * round - 4) % 10][G2] ^ G1; - G1 = FTABLE[(4 * round - 3) % 10][G3] ^ G2; - G2 = FTABLE[(4 * round - 2) % 10][G1] ^ G3; - G3 = FTABLE[(4 * round - 1) % 10][G2] ^ G1; - W1 = make_u16bit(G2, G3); - } - -/* -* Skipjack Invserse Stepping Rule 'A' -*/ -void Skipjack::step_Ai(u16bit& W1, u16bit& W2, u32bit round) const - { - W1 ^= W2 ^ round; - byte G1 = get_byte(1, W2), G2 = get_byte(0, W2), G3; - G3 = FTABLE[(4 * round - 1) % 10][G2] ^ G1; - G1 = FTABLE[(4 * round - 2) % 10][G3] ^ G2; - G2 = FTABLE[(4 * round - 3) % 10][G1] ^ G3; - G3 = FTABLE[(4 * round - 4) % 10][G2] ^ G1; - W2 = make_u16bit(G3, G2); - } - -/* -* Skipjack Invserse Stepping Rule 'B' -*/ -void Skipjack::step_Bi(u16bit& W2, u16bit& W3, u32bit round) const - { - byte G1 = get_byte(1, W2), G2 = get_byte(0, W2), G3; - G3 = FTABLE[(4 * round - 1) % 10][G2] ^ G1; - G1 = FTABLE[(4 * round - 2) % 10][G3] ^ G2; - G2 = FTABLE[(4 * round - 3) % 10][G1] ^ G3; - G3 = FTABLE[(4 * round - 4) % 10][G2] ^ G1; - W2 = make_u16bit(G3, G2); - W3 ^= W2 ^ round; - } - -/* * Skipjack Key Schedule */ void Skipjack::key_schedule(const byte key[], u32bit) @@ -157,9 +179,9 @@ void Skipjack::key_schedule(const byte key[], u32bit) 0x5E, 0x6C, 0xA9, 0x13, 0x57, 0x25, 0xB5, 0xE3, 0xBD, 0xA8, 0x3A, 0x01, 0x05, 0x59, 0x2A, 0x46 }; - for(u32bit j = 0; j != 10; ++j) - for(u32bit k = 0; k != 256; ++k) - FTABLE[j][k] = F[k ^ key[9-j]]; + for(u32bit i = 0; i != 10; ++i) + for(u32bit j = 0; j != 256; ++j) + FTAB[256*i+j] = F[j ^ key[9-i]]; } /* @@ -167,8 +189,7 @@ void Skipjack::key_schedule(const byte key[], u32bit) */ void Skipjack::clear() { - for(u32bit j = 0; j != 10; ++j) - FTABLE[j].clear(); + FTAB.clear(); } } |