diff options
Diffstat (limited to 'src/lib/block/xtea/xtea.cpp')
| -rw-r--r-- | src/lib/block/xtea/xtea.cpp | 142 |
1 files changed, 63 insertions, 79 deletions
diff --git a/src/lib/block/xtea/xtea.cpp b/src/lib/block/xtea/xtea.cpp index 333406d9b..4e5ca7e7c 100644 --- a/src/lib/block/xtea/xtea.cpp +++ b/src/lib/block/xtea/xtea.cpp @@ -1,6 +1,6 @@ /* * XTEA -* (C) 1999-2009 Jack Lloyd +* (C) 1999-2009,2016 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ @@ -10,80 +10,49 @@ 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->m_EK[0])); - in += 4 * BLOCK_SIZE; - out += 4 * BLOCK_SIZE; - blocks -= 4; - } + const u32bit* EK = &m_EK[0]; - for(size_t i = 0; i != blocks; ++i) + const size_t blocks4 = blocks / 4; + const size_t blocks_left = blocks % 4; + + BOTAN_PARALLEL_FOR(size_t i = 0; i < blocks4; i++) { - u32bit L = load_be<u32bit>(in, 0); - u32bit R = load_be<u32bit>(in, 1); + u32bit L0, R0, L1, R1, L2, R2, L3, R3; + load_be(in + 4*BLOCK_SIZE*i, L0, R0, L1, R1, L2, R2, L3, R3); - for(size_t j = 0; j != 32; ++j) + for(size_t r = 0; r != 32; ++r) { - L += (((R << 4) ^ (R >> 5)) + R) ^ m_EK[2*j]; - R += (((L << 4) ^ (L >> 5)) + L) ^ m_EK[2*j+1]; + L0 += (((R0 << 4) ^ (R0 >> 5)) + R0) ^ EK[2*r]; + L1 += (((R1 << 4) ^ (R1 >> 5)) + R1) ^ EK[2*r]; + L2 += (((R2 << 4) ^ (R2 >> 5)) + R2) ^ EK[2*r]; + L3 += (((R3 << 4) ^ (R3 >> 5)) + R3) ^ EK[2*r]; + + R0 += (((L0 << 4) ^ (L0 >> 5)) + L0) ^ EK[2*r+1]; + R1 += (((L1 << 4) ^ (L1 >> 5)) + L1) ^ EK[2*r+1]; + R2 += (((L2 << 4) ^ (L2 >> 5)) + L2) ^ EK[2*r+1]; + R3 += (((L3 << 4) ^ (L3 >> 5)) + L3) ^ EK[2*r+1]; } - store_be(out, L, R); + store_be(out + 4*BLOCK_SIZE*i, L0, R0, L1, R1, L2, R2, L3, R3); + } + + BOTAN_PARALLEL_FOR(size_t i = 0; i < blocks_left; ++i) + { + u32bit L, R; + load_be(in + BLOCK_SIZE*(4*blocks4+i), L, R); + + for(size_t r = 0; r != 32; ++r) + { + L += (((R << 4) ^ (R >> 5)) + R) ^ EK[2*r]; + R += (((L << 4) ^ (L >> 5)) + L) ^ EK[2*r+1]; + } - in += BLOCK_SIZE; - out += BLOCK_SIZE; + store_be(out + BLOCK_SIZE*(4*blocks4+i), L, R); } } @@ -92,29 +61,44 @@ void XTEA::encrypt_n(const byte in[], byte out[], size_t blocks) const */ void XTEA::decrypt_n(const byte in[], byte out[], size_t blocks) const { - while(blocks >= 4) - { - xtea_decrypt_4(in, out, &(this->m_EK[0])); - in += 4 * BLOCK_SIZE; - out += 4 * BLOCK_SIZE; - blocks -= 4; - } + const u32bit* EK = &m_EK[0]; - for(size_t i = 0; i != blocks; ++i) + const size_t blocks4 = blocks / 4; + const size_t blocks_left = blocks % 4; + + BOTAN_PARALLEL_FOR(size_t i = 0; i < blocks4; i++) { - u32bit L = load_be<u32bit>(in, 0); - u32bit R = load_be<u32bit>(in, 1); + u32bit L0, R0, L1, R1, L2, R2, L3, R3; + load_be(in + 4*BLOCK_SIZE*i, L0, R0, L1, R1, L2, R2, L3, R3); - for(size_t j = 0; j != 32; ++j) + for(size_t r = 0; r != 32; ++r) { - R -= (((L << 4) ^ (L >> 5)) + L) ^ m_EK[63 - 2*j]; - L -= (((R << 4) ^ (R >> 5)) + R) ^ m_EK[62 - 2*j]; + R0 -= (((L0 << 4) ^ (L0 >> 5)) + L0) ^ EK[63 - 2*r]; + R1 -= (((L1 << 4) ^ (L1 >> 5)) + L1) ^ EK[63 - 2*r]; + R2 -= (((L2 << 4) ^ (L2 >> 5)) + L2) ^ EK[63 - 2*r]; + R3 -= (((L3 << 4) ^ (L3 >> 5)) + L3) ^ EK[63 - 2*r]; + + L0 -= (((R0 << 4) ^ (R0 >> 5)) + R0) ^ EK[62 - 2*r]; + L1 -= (((R1 << 4) ^ (R1 >> 5)) + R1) ^ EK[62 - 2*r]; + L2 -= (((R2 << 4) ^ (R2 >> 5)) + R2) ^ EK[62 - 2*r]; + L3 -= (((R3 << 4) ^ (R3 >> 5)) + R3) ^ EK[62 - 2*r]; } - store_be(out, L, R); + store_be(out + 4*BLOCK_SIZE*i, L0, R0, L1, R1, L2, R2, L3, R3); + } + + BOTAN_PARALLEL_FOR(size_t i = 0; i < blocks_left; ++i) + { + u32bit L, R; + load_be(in + BLOCK_SIZE*(4*blocks4+i), L, R); + + for(size_t r = 0; r != 32; ++r) + { + R -= (((L << 4) ^ (L >> 5)) + L) ^ m_EK[63 - 2*r]; + L -= (((R << 4) ^ (R >> 5)) + R) ^ m_EK[62 - 2*r]; + } - in += BLOCK_SIZE; - out += BLOCK_SIZE; + store_be(out + BLOCK_SIZE*(4*blocks4+i), L, R); } } |