/************************************************* * Blowfish Source File * * (C) 1999-2007 Jack Lloyd * *************************************************/ #include #include namespace Botan { /************************************************* * Blowfish Encryption * *************************************************/ void Blowfish::enc(const byte in[], byte out[]) const { u32bit L = load_be(in, 0); u32bit R = load_be(in, 1); for(u32bit j = 0; j != 16; j += 2) { L ^= P[j]; R ^= ((S1[get_byte(0, L)] + S2[get_byte(1, L)]) ^ S3[get_byte(2, L)]) + S4[get_byte(3, L)]; R ^= P[j+1]; L ^= ((S1[get_byte(0, R)] + S2[get_byte(1, R)]) ^ S3[get_byte(2, R)]) + S4[get_byte(3, R)]; } L ^= P[16]; R ^= P[17]; store_be(out, R, L); } /************************************************* * Blowfish Decryption * *************************************************/ void Blowfish::dec(const byte in[], byte out[]) const { u32bit L = load_be(in, 0); u32bit R = load_be(in, 1); for(u32bit j = 17; j != 1; j -= 2) { L ^= P[j]; R ^= ((S1[get_byte(0, L)] + S2[get_byte(1, L)]) ^ S3[get_byte(2, L)]) + S4[get_byte(3, L)]; R ^= P[j-1]; L ^= ((S1[get_byte(0, R)] + S2[get_byte(1, R)]) ^ S3[get_byte(2, R)]) + S4[get_byte(3, R)]; } L ^= P[1]; R ^= P[0]; store_be(out, R, L); } /************************************************* * Blowfish Key Schedule * *************************************************/ void Blowfish::key(const byte key[], u32bit length) { clear(); for(u32bit j = 0, k = 0; j != 18; ++j, k += 4) P[j] ^= make_u32bit(key[(k ) % length], key[(k+1) % length], key[(k+2) % length], key[(k+3) % length]); u32bit L = 0, R = 0; generate_sbox(P, 18, L, R); generate_sbox(S1, 256, L, R); generate_sbox(S2, 256, L, R); generate_sbox(S3, 256, L, R); generate_sbox(S4, 256, L, R); } /************************************************* * Generate one of the Sboxes * *************************************************/ void Blowfish::generate_sbox(u32bit Box[], u32bit size, u32bit& L, u32bit& R) const { for(u32bit j = 0; j != size; j += 2) { for(u32bit k = 0; k != 16; k += 2) { L ^= P[k]; R ^= ((S1[get_byte(0, L)] + S2[get_byte(1, L)]) ^ S3[get_byte(2, L)]) + S4[get_byte(3, L)]; R ^= P[k+1]; L ^= ((S1[get_byte(0, R)] + S2[get_byte(1, R)]) ^ S3[get_byte(2, R)]) + S4[get_byte(3, R)]; } u32bit T = R; R = L ^ P[16]; L = T ^ P[17]; Box[j] = L; Box[j+1] = R; } } /************************************************* * Clear memory of sensitive data * *************************************************/ void Blowfish::clear() throw() { P.copy(PBOX, 18); S1.copy(SBOX + 0, 256); S2.copy(SBOX + 256, 256); S3.copy(SBOX + 512, 256); S4.copy(SBOX + 768, 256); } }