diff options
author | lloyd <[email protected]> | 2006-05-18 18:33:19 +0000 |
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committer | lloyd <[email protected]> | 2006-05-18 18:33:19 +0000 |
commit | a2c99d3270eb73ef2db5704fc54356c6b75096f8 (patch) | |
tree | ad3d6c4fcc8dd0f403f8105598943616246fe172 /src/xtea.cpp |
Initial checkin1.5.6
Diffstat (limited to 'src/xtea.cpp')
-rw-r--r-- | src/xtea.cpp | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/src/xtea.cpp b/src/xtea.cpp new file mode 100644 index 000000000..064066dc9 --- /dev/null +++ b/src/xtea.cpp @@ -0,0 +1,81 @@ +/************************************************* +* XTEA Source File * +* (C) 1999-2006 The Botan Project * +*************************************************/ + +#include <botan/xtea.h> +#include <botan/bit_ops.h> +#include <botan/parsing.h> + +namespace Botan { + +/************************************************* +* XTEA Encryption * +*************************************************/ +void XTEA::enc(const byte in[], byte out[]) const + { + u32bit left = make_u32bit(in[0], in[1], in[2], in[3]), + right = make_u32bit(in[4], in[5], in[6], in[7]); + for(u32bit j = 0; j != 32; ++j) + { + left += (((right << 4) ^ (right >> 5)) + right) ^ EK[2*j]; + right += (((left << 4) ^ (left >> 5)) + left) ^ EK[2*j+1]; + } + out[0] = get_byte(0, left); out[1] = get_byte(1, left); + out[2] = get_byte(2, left); out[3] = get_byte(3, left); + out[4] = get_byte(0, right); out[5] = get_byte(1, right); + out[6] = get_byte(2, right); out[7] = get_byte(3, right); + } + +/************************************************* +* XTEA Decryption * +*************************************************/ +void XTEA::dec(const byte in[], byte out[]) const + { + u32bit left = make_u32bit(in[0], in[1], in[2], in[3]), + right = make_u32bit(in[4], in[5], in[6], in[7]); + for(u32bit j = 32; j > 0; --j) + { + right -= (((left << 4) ^ (left >> 5)) + left) ^ EK[2*j - 1]; + left -= (((right << 4) ^ (right >> 5)) + right) ^ EK[2*j - 2]; + } + out[0] = get_byte(0, left); out[1] = get_byte(1, left); + out[2] = get_byte(2, left); out[3] = get_byte(3, left); + out[4] = get_byte(0, right); out[5] = get_byte(1, right); + out[6] = get_byte(2, right); out[7] = get_byte(3, right); + } + +/************************************************* +* XTEA Key Schedule * +*************************************************/ +void XTEA::key(const byte key[], u32bit) + { + static const u32bit DELTAS[64] = { + 0x00000000, 0x9E3779B9, 0x9E3779B9, 0x3C6EF372, 0x3C6EF372, 0xDAA66D2B, + 0xDAA66D2B, 0x78DDE6E4, 0x78DDE6E4, 0x1715609D, 0x1715609D, 0xB54CDA56, + 0xB54CDA56, 0x5384540F, 0x5384540F, 0xF1BBCDC8, 0xF1BBCDC8, 0x8FF34781, + 0x8FF34781, 0x2E2AC13A, 0x2E2AC13A, 0xCC623AF3, 0xCC623AF3, 0x6A99B4AC, + 0x6A99B4AC, 0x08D12E65, 0x08D12E65, 0xA708A81E, 0xA708A81E, 0x454021D7, + 0x454021D7, 0xE3779B90, 0xE3779B90, 0x81AF1549, 0x81AF1549, 0x1FE68F02, + 0x1FE68F02, 0xBE1E08BB, 0xBE1E08BB, 0x5C558274, 0x5C558274, 0xFA8CFC2D, + 0xFA8CFC2D, 0x98C475E6, 0x98C475E6, 0x36FBEF9F, 0x36FBEF9F, 0xD5336958, + 0xD5336958, 0x736AE311, 0x736AE311, 0x11A25CCA, 0x11A25CCA, 0xAFD9D683, + 0xAFD9D683, 0x4E11503C, 0x4E11503C, 0xEC48C9F5, 0xEC48C9F5, 0x8A8043AE, + 0x8A8043AE, 0x28B7BD67, 0x28B7BD67, 0xC6EF3720 }; + + static const byte KEY_INDEX[64] = { + 0x00, 0x03, 0x01, 0x02, 0x02, 0x01, 0x03, 0x00, 0x00, 0x00, 0x01, 0x03, + 0x02, 0x02, 0x03, 0x01, 0x00, 0x00, 0x01, 0x00, 0x02, 0x03, 0x03, 0x02, + 0x00, 0x01, 0x01, 0x01, 0x02, 0x00, 0x03, 0x03, 0x00, 0x02, 0x01, 0x01, + 0x02, 0x01, 0x03, 0x00, 0x00, 0x03, 0x01, 0x02, 0x02, 0x01, 0x03, 0x01, + 0x00, 0x00, 0x01, 0x03, 0x02, 0x02, 0x03, 0x02, 0x00, 0x01, 0x01, 0x00, + 0x02, 0x03, 0x03, 0x02 }; + + SecureBuffer<u32bit, 4> UK; + for(u32bit j = 0; j != 4; ++j) + UK[j] = make_u32bit(key[4*j], key[4*j+1], key[4*j+2], key[4*j+3]); + for(u32bit j = 0; j != 64; ++j) + EK[j] = DELTAS[j] + UK[KEY_INDEX[j]]; + } + +} |