diff options
Diffstat (limited to 'modules/ciphers/rc6')
-rw-r--r-- | modules/ciphers/rc6/modinfo.txt | 10 | ||||
-rw-r--r-- | modules/ciphers/rc6/rc6.cpp | 120 | ||||
-rw-r--r-- | modules/ciphers/rc6/rc6.h | 33 |
3 files changed, 163 insertions, 0 deletions
diff --git a/modules/ciphers/rc6/modinfo.txt b/modules/ciphers/rc6/modinfo.txt new file mode 100644 index 000000000..1457e78c1 --- /dev/null +++ b/modules/ciphers/rc6/modinfo.txt @@ -0,0 +1,10 @@ +realname "RC6" + +define RC6 + +load_on auto + +<add> +rc6.cpp +rc6.h +</add> diff --git a/modules/ciphers/rc6/rc6.cpp b/modules/ciphers/rc6/rc6.cpp new file mode 100644 index 000000000..67d765222 --- /dev/null +++ b/modules/ciphers/rc6/rc6.cpp @@ -0,0 +1,120 @@ +/************************************************* +* RC6 Source File * +* (C) 1999-2007 Jack Lloyd * +*************************************************/ + +#include <botan/rc6.h> +#include <botan/loadstor.h> +#include <botan/bit_ops.h> +#include <algorithm> + +namespace Botan { + +/************************************************* +* RC6 Encryption * +*************************************************/ +void RC6::enc(const byte in[], byte out[]) const + { + u32bit A = load_le<u32bit>(in, 0); + u32bit B = load_le<u32bit>(in, 1); + u32bit C = load_le<u32bit>(in, 2); + u32bit D = load_le<u32bit>(in, 3); + + B += S[0]; D += S[1]; + + for(u32bit j = 0; j != 20; j += 4) + { + u32bit T1, T2; + + T1 = rotate_left(B*(2*B+1), 5); + T2 = rotate_left(D*(2*D+1), 5); + A = rotate_left(A ^ T1, T2 % 32) + S[2*j+2]; + C = rotate_left(C ^ T2, T1 % 32) + S[2*j+3]; + + T1 = rotate_left(C*(2*C+1), 5); + T2 = rotate_left(A*(2*A+1), 5); + B = rotate_left(B ^ T1, T2 % 32) + S[2*j+4]; + D = rotate_left(D ^ T2, T1 % 32) + S[2*j+5]; + + T1 = rotate_left(D*(2*D+1), 5); + T2 = rotate_left(B*(2*B+1), 5); + C = rotate_left(C ^ T1, T2 % 32) + S[2*j+6]; + A = rotate_left(A ^ T2, T1 % 32) + S[2*j+7]; + + T1 = rotate_left(A*(2*A+1), 5); + T2 = rotate_left(C*(2*C+1), 5); + D = rotate_left(D ^ T1, T2 % 32) + S[2*j+8]; + B = rotate_left(B ^ T2, T1 % 32) + S[2*j+9]; + } + + A += S[42]; C += S[43]; + + store_le(out, A, B, C, D); + } + +/************************************************* +* RC6 Decryption * +*************************************************/ +void RC6::dec(const byte in[], byte out[]) const + { + u32bit A = load_le<u32bit>(in, 0); + u32bit B = load_le<u32bit>(in, 1); + u32bit C = load_le<u32bit>(in, 2); + u32bit D = load_le<u32bit>(in, 3); + + C -= S[43]; A -= S[42]; + + for(u32bit j = 0; j != 20; j += 4) + { + u32bit T1, T2; + + T1 = rotate_left(A*(2*A+1), 5); + T2 = rotate_left(C*(2*C+1), 5); + B = rotate_right(B - S[41 - 2*j], T1 % 32) ^ T2; + D = rotate_right(D - S[40 - 2*j], T2 % 32) ^ T1; + + T1 = rotate_left(D*(2*D+1), 5); + T2 = rotate_left(B*(2*B+1), 5); + A = rotate_right(A - S[39 - 2*j], T1 % 32) ^ T2; + C = rotate_right(C - S[38 - 2*j], T2 % 32) ^ T1; + + T1 = rotate_left(C*(2*C+1), 5); + T2 = rotate_left(A*(2*A+1), 5); + D = rotate_right(D - S[37 - 2*j], T1 % 32) ^ T2; + B = rotate_right(B - S[36 - 2*j], T2 % 32) ^ T1; + + T1 = rotate_left(B*(2*B+1), 5); + T2 = rotate_left(D*(2*D+1), 5); + C = rotate_right(C - S[35 - 2*j], T1 % 32) ^ T2; + A = rotate_right(A - S[34 - 2*j], T2 % 32) ^ T1; + } + + D -= S[1]; B -= S[0]; + + store_le(out, A, B, C, D); + } + +/************************************************* +* RC6 Key Schedule * +*************************************************/ +void RC6::key(const byte key[], u32bit length) + { + const u32bit WORD_KEYLENGTH = (((length - 1) / 4) + 1), + MIX_ROUNDS = 3*std::max(WORD_KEYLENGTH, S.size()); + S[0] = 0xB7E15163; + for(u32bit j = 1; j != S.size(); ++j) + S[j] = S[j-1] + 0x9E3779B9; + + SecureBuffer<u32bit, 8> K; + for(s32bit j = length-1; j >= 0; --j) + K[j/4] = (K[j/4] << 8) + key[j]; + for(u32bit j = 0, A = 0, B = 0; j != MIX_ROUNDS; ++j) + { + A = rotate_left(S[j % S.size()] + A + B, 3); + B = rotate_left(K[j % WORD_KEYLENGTH] + A + B, (A + B) % 32); + S[j % S.size()] = A; + K[j % WORD_KEYLENGTH] = B; + } + } + +} diff --git a/modules/ciphers/rc6/rc6.h b/modules/ciphers/rc6/rc6.h new file mode 100644 index 000000000..d629b0995 --- /dev/null +++ b/modules/ciphers/rc6/rc6.h @@ -0,0 +1,33 @@ +/************************************************* +* RC6 Header File * +* (C) 1999-2007 Jack Lloyd * +*************************************************/ + +#ifndef BOTAN_RC6_H__ +#define BOTAN_RC6_H__ + +#include <botan/base.h> + +namespace Botan { + +/************************************************* +* RC6 * +*************************************************/ +class BOTAN_DLL RC6 : public BlockCipher + { + public: + void clear() throw() { S.clear(); } + std::string name() const { return "RC6"; } + BlockCipher* clone() const { return new RC6; } + RC6() : BlockCipher(16, 1, 32) {} + private: + void enc(const byte[], byte[]) const; + void dec(const byte[], byte[]) const; + void key(const byte[], u32bit); + + SecureBuffer<u32bit, 44> S; + }; + +} + +#endif |