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/*
* Threefish-512
* (C) 2013 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/threefish.h>
#include <botan/rotate.h>
#include <botan/loadstor.h>
namespace Botan {
secure_vector<byte> Threefish_512::start(const byte tweak[], size_t tweak_len)
{
if(!valid_nonce_length(tweak_len))
throw Invalid_IV_Length(name(), tweak_len);
m_T.resize(3);
m_T[0] = load_le<u64bit>(tweak, 0);
m_T[1] = load_le<u64bit>(tweak, 1);
m_T[2] = m_T[0] ^ m_T[1];
return secure_vector<byte>();
}
void Threefish_512::update(secure_vector<byte>& blocks, size_t offset)
{
byte* buf = &blocks[offset];
size_t sz = blocks.size() - offset;
BOTAN_ASSERT(sz % update_granularity() == 0, "Block sized input");
BOTAN_ASSERT(m_T.size() == 3, "Tweak was set");
#define THREEFISH_ROUND(I1,I2,I3,I4,I5,I6,I7,I8,ROT1,ROT2,ROT3,ROT4) \
do { \
X##I1 += X##I2; X##I2 = rotate_left(X##I2, ROT1) ^ X##I1; \
X##I3 += X##I4; X##I4 = rotate_left(X##I4, ROT2) ^ X##I3; \
X##I5 += X##I6; X##I6 = rotate_left(X##I6, ROT3) ^ X##I5; \
X##I7 += X##I8; X##I8 = rotate_left(X##I8, ROT4) ^ X##I7; \
} while(0)
#define THREEFISH_INJECT_KEY(r) \
do { \
X0 += m_K[(r ) % 9]; \
X1 += m_K[(r+1) % 9]; \
X2 += m_K[(r+2) % 9]; \
X3 += m_K[(r+3) % 9]; \
X4 += m_K[(r+4) % 9]; \
X5 += m_K[(r+5) % 9] + m_T[(r ) % 3]; \
X6 += m_K[(r+6) % 9] + m_T[(r+1) % 3]; \
X7 += m_K[(r+7) % 9] + (r); \
} while(0)
#define THREEFISH_8_ROUNDS(R1,R2) \
do { \
THREEFISH_ROUND(0,1,2,3,4,5,6,7, 46,36,19,37); \
THREEFISH_ROUND(2,1,4,7,6,5,0,3, 33,27,14,42); \
THREEFISH_ROUND(4,1,6,3,0,5,2,7, 17,49,36,39); \
THREEFISH_ROUND(6,1,0,7,2,5,4,3, 44, 9,54,56); \
\
THREEFISH_INJECT_KEY(R1); \
\
THREEFISH_ROUND(0,1,2,3,4,5,6,7, 39,30,34,24); \
THREEFISH_ROUND(2,1,4,7,6,5,0,3, 13,50,10,17); \
THREEFISH_ROUND(4,1,6,3,0,5,2,7, 25,29,39,43); \
THREEFISH_ROUND(6,1,0,7,2,5,4,3, 8,35,56,22); \
\
THREEFISH_INJECT_KEY(R2); \
} while(0)
while(sz)
{
u64bit X0 = load_le<u64bit>(buf, 0);
u64bit X1 = load_le<u64bit>(buf, 1);
u64bit X2 = load_le<u64bit>(buf, 2);
u64bit X3 = load_le<u64bit>(buf, 3);
u64bit X4 = load_le<u64bit>(buf, 4);
u64bit X5 = load_le<u64bit>(buf, 5);
u64bit X6 = load_le<u64bit>(buf, 6);
u64bit X7 = load_le<u64bit>(buf, 7);
THREEFISH_INJECT_KEY(0);
THREEFISH_8_ROUNDS(1,2);
THREEFISH_8_ROUNDS(3,4);
THREEFISH_8_ROUNDS(5,6);
THREEFISH_8_ROUNDS(7,8);
THREEFISH_8_ROUNDS(9,10);
THREEFISH_8_ROUNDS(11,12);
THREEFISH_8_ROUNDS(13,14);
THREEFISH_8_ROUNDS(15,16);
THREEFISH_8_ROUNDS(17,18);
store_le(buf, X0, X1, X2, X3, X4, X5, X6, X7);
buf += 64;
sz -= 64;
}
#undef THREEFISH_8_ROUNDS
#undef THREEFISH_INJECT_KEY
#undef THREEFISH_ROUND
}
Key_Length_Specification Threefish_512::key_spec() const
{
return Key_Length_Specification(64);
}
void Threefish_512::key_schedule(const byte key[], size_t)
{
// todo: define key schedule for smaller keys
m_K.resize(9);
for(size_t i = 0; i != 8; ++i)
m_K[i] = load_le<u64bit>(key, i);
m_K[8] = m_K[0] ^ m_K[1] ^ m_K[2] ^ m_K[3] ^
m_K[4] ^ m_K[5] ^ m_K[6] ^ m_K[7] ^ 0x1BD11BDAA9FC1A22;
}
void Threefish_512::finish(secure_vector<byte>& blocks, size_t offset)
{
update(blocks, offset);
m_T.clear();
}
size_t Threefish_512::output_length(size_t input_length) const
{
if(input_length % update_granularity() == 0)
throw std::invalid_argument("Threefish - invalid input length " + std::to_string(input_length));
return input_length;
}
size_t Threefish_512::update_granularity() const
{
return 64; // single block
}
size_t Threefish_512::minimum_final_size() const
{
return 0;
}
size_t Threefish_512::default_nonce_length() const
{
return 16;
}
bool Threefish_512::valid_nonce_length(size_t nonce_len) const
{
return default_nonce_length() == nonce_len;
}
void Threefish_512::clear()
{
zeroise(m_K);
}
}
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