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Diffstat (limited to 'src/safer_sk.cpp')
| -rw-r--r-- | src/safer_sk.cpp | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/src/safer_sk.cpp b/src/safer_sk.cpp new file mode 100644 index 000000000..6e7f298a4 --- /dev/null +++ b/src/safer_sk.cpp @@ -0,0 +1,112 @@ +/************************************************* +* SAFER-SK Source File * +* (C) 1999-2006 The Botan Project * +*************************************************/ + +#include <botan/safer_sk.h> +#include <botan/bit_ops.h> +#include <botan/parsing.h> + +namespace Botan { + +/************************************************* +* SAFER-SK Encryption * +*************************************************/ +void SAFER_SK::enc(const byte in[], byte out[]) const + { + byte A = in[0], B = in[1], C = in[2], D = in[3], + E = in[4], F = in[5], G = in[6], H = in[7], X, Y; + for(u32bit j = 0; j != 16*ROUNDS; j += 16) + { + A = EXP[A ^ EK[j ]]; B = LOG[B + EK[j+1]]; + C = LOG[C + EK[j+2]]; D = EXP[D ^ EK[j+3]]; + E = EXP[E ^ EK[j+4]]; F = LOG[F + EK[j+5]]; + G = LOG[G + EK[j+6]]; H = EXP[H ^ EK[j+7]]; + A += EK[j+ 8]; B ^= EK[j+ 9]; C ^= EK[j+10]; D += EK[j+11]; + E += EK[j+12]; F ^= EK[j+13]; G ^= EK[j+14]; H += EK[j+15]; + B += A; D += C; F += E; H += G; A += B; C += D; E += F; G += H; + C += A; G += E; D += B; H += F; A += C; E += G; B += D; F += H; + H += D; Y = D + H; D = B + F; X = B + D; B = A + E; + A += B; F = C + G; E = C + F; C = X; G = Y; + } + out[0] = A ^ EK[16*ROUNDS+0]; out[1] = B + EK[16*ROUNDS+1]; + out[2] = C + EK[16*ROUNDS+2]; out[3] = D ^ EK[16*ROUNDS+3]; + out[4] = E ^ EK[16*ROUNDS+4]; out[5] = F + EK[16*ROUNDS+5]; + out[6] = G + EK[16*ROUNDS+6]; out[7] = H ^ EK[16*ROUNDS+7]; + } + +/************************************************* +* SAFER-SK Decryption * +*************************************************/ +void SAFER_SK::dec(const byte in[], byte out[]) const + { + byte A = in[0], B = in[1], C = in[2], D = in[3], + E = in[4], F = in[5], G = in[6], H = in[7]; + A ^= EK[16*ROUNDS+0]; B -= EK[16*ROUNDS+1]; C -= EK[16*ROUNDS+2]; + D ^= EK[16*ROUNDS+3]; E ^= EK[16*ROUNDS+4]; F -= EK[16*ROUNDS+5]; + G -= EK[16*ROUNDS+6]; H ^= EK[16*ROUNDS+7]; + for(s32bit j = 16*(ROUNDS-1); j >= 0; j -= 16) + { + byte T = E; E = B; B = C; C = T; T = F; F = D; D = G; G = T; + A -= E; B -= F; C -= G; D -= H; E -= A; F -= B; G -= C; H -= D; + A -= C; E -= G; B -= D; F -= H; C -= A; G -= E; D -= B; H -= F; + A -= B; C -= D; E -= F; G -= H; B -= A; D -= C; F -= E; H -= G; + A = LOG[A - EK[j+8 ] + 256]; B = EXP[B ^ EK[j+9 ]]; + C = EXP[C ^ EK[j+10]]; D = LOG[D - EK[j+11] + 256]; + E = LOG[E - EK[j+12] + 256]; F = EXP[F ^ EK[j+13]]; + G = EXP[G ^ EK[j+14]]; H = LOG[H - EK[j+15] + 256]; + A ^= EK[j+0]; B -= EK[j+1]; C -= EK[j+2]; D ^= EK[j+3]; + E ^= EK[j+4]; F -= EK[j+5]; G -= EK[j+6]; H ^= EK[j+7]; + } + out[0] = A; out[1] = B; out[2] = C; out[3] = D; + out[4] = E; out[5] = F; out[6] = G; out[7] = H; + } + +/************************************************* +* SAFER-SK Key Schedule * +*************************************************/ +void SAFER_SK::key(const byte key[], u32bit) + { + SecureBuffer<byte, 18> KB; + + for(u32bit j = 0; j != 8; ++j) + { + KB[ 8] ^= KB[j] = rotate_left(key[j], 5); + KB[17] ^= KB[j+9] = EK[j] = key[j+8]; + } + for(u32bit j = 0; j != ROUNDS; ++j) + { + for(u32bit k = 0; k != 18; ++k) + KB[k] = rotate_left(KB[k], 6); + for(u32bit k = 0; k != 16; ++k) + EK[16*j+k+8] = KB[KEY_INDEX[16*j+k]] + BIAS[16*j+k]; + } + } + +/************************************************* +* Return the name of this type * +*************************************************/ +std::string SAFER_SK::name() const + { + return "SAFER-SK(" + to_string(ROUNDS) + ")"; + } + +/************************************************* +* Return a clone of this object * +*************************************************/ +BlockCipher* SAFER_SK::clone() const + { + return new SAFER_SK(ROUNDS); + } + +/************************************************* +* SAFER-SK Constructor * +*************************************************/ +SAFER_SK::SAFER_SK(u32bit rounds) : BlockCipher(8, 16), + EK(16 * rounds + 8), ROUNDS(rounds) + { + if(ROUNDS > 13 || ROUNDS == 0) + throw Invalid_Argument(name() + ": Invalid number of rounds"); + } + +} |