diff options
author | lloyd <[email protected]> | 2014-01-10 03:41:59 +0000 |
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committer | lloyd <[email protected]> | 2014-01-10 03:41:59 +0000 |
commit | 6894dca64c04936d07048c0e8cbf7e25858548c3 (patch) | |
tree | 5d572bfde9fe667dab14e3f04b5285a85d8acd95 /src/lib/block/xtea | |
parent | 9efa3be92442afb3d0b69890a36c7f122df18eda (diff) |
Move lib into src
Diffstat (limited to 'src/lib/block/xtea')
-rw-r--r-- | src/lib/block/xtea/info.txt | 1 | ||||
-rw-r--r-- | src/lib/block/xtea/xtea.cpp | 146 | ||||
-rw-r--r-- | src/lib/block/xtea/xtea.h | 40 |
3 files changed, 187 insertions, 0 deletions
diff --git a/src/lib/block/xtea/info.txt b/src/lib/block/xtea/info.txt new file mode 100644 index 000000000..e2cc8ac34 --- /dev/null +++ b/src/lib/block/xtea/info.txt @@ -0,0 +1 @@ +define XTEA 20131128 diff --git a/src/lib/block/xtea/xtea.cpp b/src/lib/block/xtea/xtea.cpp new file mode 100644 index 000000000..165a6ea6a --- /dev/null +++ b/src/lib/block/xtea/xtea.cpp @@ -0,0 +1,146 @@ +/* +* XTEA +* (C) 1999-2009 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#include <botan/xtea.h> +#include <botan/loadstor.h> + +namespace Botan { + +namespace { + +void xtea_encrypt_4(const byte in[32], byte out[32], const u32bit EK[64]) + { + u32bit L0, R0, L1, R1, L2, R2, L3, R3; + load_be(in, L0, R0, L1, R1, L2, R2, L3, R3); + + for(size_t i = 0; i != 32; ++i) + { + L0 += (((R0 << 4) ^ (R0 >> 5)) + R0) ^ EK[2*i]; + L1 += (((R1 << 4) ^ (R1 >> 5)) + R1) ^ EK[2*i]; + L2 += (((R2 << 4) ^ (R2 >> 5)) + R2) ^ EK[2*i]; + L3 += (((R3 << 4) ^ (R3 >> 5)) + R3) ^ EK[2*i]; + + R0 += (((L0 << 4) ^ (L0 >> 5)) + L0) ^ EK[2*i+1]; + R1 += (((L1 << 4) ^ (L1 >> 5)) + L1) ^ EK[2*i+1]; + R2 += (((L2 << 4) ^ (L2 >> 5)) + L2) ^ EK[2*i+1]; + R3 += (((L3 << 4) ^ (L3 >> 5)) + L3) ^ EK[2*i+1]; + } + + store_be(out, L0, R0, L1, R1, L2, R2, L3, R3); + } + +void xtea_decrypt_4(const byte in[32], byte out[32], const u32bit EK[64]) + { + u32bit L0, R0, L1, R1, L2, R2, L3, R3; + load_be(in, L0, R0, L1, R1, L2, R2, L3, R3); + + for(size_t i = 0; i != 32; ++i) + { + R0 -= (((L0 << 4) ^ (L0 >> 5)) + L0) ^ EK[63 - 2*i]; + R1 -= (((L1 << 4) ^ (L1 >> 5)) + L1) ^ EK[63 - 2*i]; + R2 -= (((L2 << 4) ^ (L2 >> 5)) + L2) ^ EK[63 - 2*i]; + R3 -= (((L3 << 4) ^ (L3 >> 5)) + L3) ^ EK[63 - 2*i]; + + L0 -= (((R0 << 4) ^ (R0 >> 5)) + R0) ^ EK[62 - 2*i]; + L1 -= (((R1 << 4) ^ (R1 >> 5)) + R1) ^ EK[62 - 2*i]; + L2 -= (((R2 << 4) ^ (R2 >> 5)) + R2) ^ EK[62 - 2*i]; + L3 -= (((R3 << 4) ^ (R3 >> 5)) + R3) ^ EK[62 - 2*i]; + } + + store_be(out, L0, R0, L1, R1, L2, R2, L3, R3); + } + +} + +/* +* XTEA Encryption +*/ +void XTEA::encrypt_n(const byte in[], byte out[], size_t blocks) const + { + while(blocks >= 4) + { + xtea_encrypt_4(in, out, &(this->EK[0])); + in += 4 * BLOCK_SIZE; + out += 4 * BLOCK_SIZE; + blocks -= 4; + } + + for(size_t i = 0; i != blocks; ++i) + { + u32bit L = load_be<u32bit>(in, 0); + u32bit R = load_be<u32bit>(in, 1); + + for(size_t j = 0; j != 32; ++j) + { + L += (((R << 4) ^ (R >> 5)) + R) ^ EK[2*j]; + R += (((L << 4) ^ (L >> 5)) + L) ^ EK[2*j+1]; + } + + store_be(out, L, R); + + in += BLOCK_SIZE; + out += BLOCK_SIZE; + } + } + +/* +* XTEA Decryption +*/ +void XTEA::decrypt_n(const byte in[], byte out[], size_t blocks) const + { + while(blocks >= 4) + { + xtea_decrypt_4(in, out, &(this->EK[0])); + in += 4 * BLOCK_SIZE; + out += 4 * BLOCK_SIZE; + blocks -= 4; + } + + for(size_t i = 0; i != blocks; ++i) + { + u32bit L = load_be<u32bit>(in, 0); + u32bit R = load_be<u32bit>(in, 1); + + for(size_t j = 0; j != 32; ++j) + { + R -= (((L << 4) ^ (L >> 5)) + L) ^ EK[63 - 2*j]; + L -= (((R << 4) ^ (R >> 5)) + R) ^ EK[62 - 2*j]; + } + + store_be(out, L, R); + + in += BLOCK_SIZE; + out += BLOCK_SIZE; + } + } + +/* +* XTEA Key Schedule +*/ +void XTEA::key_schedule(const byte key[], size_t) + { + EK.resize(64); + + secure_vector<u32bit> UK(4); + for(size_t i = 0; i != 4; ++i) + UK[i] = load_be<u32bit>(key, i); + + u32bit D = 0; + for(size_t i = 0; i != 64; i += 2) + { + EK[i ] = D + UK[D % 4]; + D += 0x9E3779B9; + EK[i+1] = D + UK[(D >> 11) % 4]; + } + } + +void XTEA::clear() + { + zap(EK); + } + +} diff --git a/src/lib/block/xtea/xtea.h b/src/lib/block/xtea/xtea.h new file mode 100644 index 000000000..42acc35a5 --- /dev/null +++ b/src/lib/block/xtea/xtea.h @@ -0,0 +1,40 @@ +/* +* XTEA +* (C) 1999-2007 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#ifndef BOTAN_XTEA_H__ +#define BOTAN_XTEA_H__ + +#include <botan/block_cipher.h> + +namespace Botan { + +/** +* XTEA +*/ +class BOTAN_DLL XTEA : public Block_Cipher_Fixed_Params<8, 16> + { + public: + void encrypt_n(const byte in[], byte out[], size_t blocks) const; + void decrypt_n(const byte in[], byte out[], size_t blocks) const; + + void clear(); + std::string name() const { return "XTEA"; } + BlockCipher* clone() const { return new XTEA; } + protected: + /** + * @return const reference to the key schedule + */ + const secure_vector<u32bit>& get_EK() const { return EK; } + + private: + void key_schedule(const byte[], size_t); + secure_vector<u32bit> EK; + }; + +} + +#endif |