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AEAD/Chacha20/Poly1305 encrypt multiple buffers

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orignal 2018-11-30 14:41:14 -05:00
parent 0c9ebc36d4
commit e68f1dbc99
5 changed files with 130 additions and 69 deletions
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115
libi2pd/ChaCha20.cpp
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@ -50,44 +50,26 @@ void quarterround(uint32_t *x, int a, int b, int c, int d)
x[c] += x[d]; x[b] = rotl32(x[b] ^ x[c], 7);
}
struct State_t
{
State_t() {};
State_t(State_t &&) = delete;
State_t & operator += (const State_t & other)
{
for(int i = 0; i < 16; i++)
data[i] += other.data[i];
return *this;
}
void Copy(const State_t & other)
{
memcpy(data, other.data, sizeof(uint32_t) * 16);
}
uint32_t data[16];
};
struct Block_t
{
Block_t() {};
Block_t(Block_t &&) = delete;
struct Block_t
{
Block_t() {};
Block_t(Block_t &&) = delete;
uint8_t data[blocksize];
uint8_t data[blocksize];
void operator << (const Chacha20State & st)
{
int i;
for (i = 0; i < 16; i++)
u32t8le(st.data[i], data + (i << 2));
}
};
void operator << (const State_t & st)
{
int i;
for (i = 0; i < 16; i++)
u32t8le(st.data[i], data + (i << 2));
}
};
void block(const State_t &input, Block_t & block, int rounds)
void block(const Chacha20State &input, Block_t & block, int rounds)
{
int i;
State_t x;
Chacha20State x;
x.Copy(input);
for (i = rounds; i > 0; i -= 2)
@ -107,44 +89,41 @@ void block(const State_t &input, Block_t & block, int rounds)
}
} // namespace chacha
void Chacha20Init (Chacha20State& state, const uint8_t * nonce, const uint8_t * key, uint32_t counter)
{
state.data[0] = 0x61707865;
state.data[1] = 0x3320646e;
state.data[2] = 0x79622d32;
state.data[3] = 0x6b206574;
for (size_t i = 0; i < 8; i++)
state.data[4 + i] = chacha::u8t32le(key + i * 4);
state.data[12] = counter;
for (size_t i = 0; i < 3; i++)
state.data[13 + i] = chacha::u8t32le(nonce + i * 4);
}
void Chacha20Encrypt (Chacha20State& state, uint8_t * buf, size_t sz)
{
chacha::Block_t block;
for (size_t i = 0; i < sz; i += chacha::blocksize)
{
chacha::block(state, block, chacha::rounds);
state.data[12]++;
for (size_t j = i; j < i + chacha::blocksize; j++)
{
if (j >= sz) break;
buf[j] ^= block.data[j - i];
}
}
}
void chacha20(uint8_t * buf, size_t sz, const uint8_t * nonce, const uint8_t * key, uint32_t counter)
{
chacha::State_t state;
chacha::Block_t block;
size_t i, j;
state.data[0] = 0x61707865;
state.data[1] = 0x3320646e;
state.data[2] = 0x79622d32;
state.data[3] = 0x6b206574;
for (i = 0; i < 8; i++)
state.data[4 + i] = chacha::u8t32le(key + i * 4);
state.data[12] = counter;
for (i = 0; i < 3; i++)
state.data[13 + i] = chacha::u8t32le(nonce + i * 4);
for (i = 0; i < sz; i += chacha::blocksize)
{
chacha::block(state, block, chacha::rounds);
state.data[12]++;
for (j = i; j < i + chacha::blocksize; j++)
{
if (j >= sz) break;
buf[j] ^= block.data[j - i];
}
}
}
void chacha20(uint8_t * buf, size_t sz, const uint8_t * nonce, const uint8_t * key, uint32_t counter)
{
Chacha20State state;
Chacha20Init (state, nonce, key, counter);
Chacha20Encrypt (state, buf, sz);
}
}
}
#endif