/usr/include/botan-2/botan/chacha.h is in libbotan-2-dev 2.4.0-5ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 | /*
* ChaCha20
* (C) 2014 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_CHACHA_H_
#define BOTAN_CHACHA_H_
#include <botan/stream_cipher.h>
namespace Botan {
/**
* DJB's ChaCha (https://cr.yp.to/chacha.html)
*/
class BOTAN_PUBLIC_API(2,0) ChaCha final : public StreamCipher
{
public:
StreamCipher* clone() const override { return new ChaCha(m_rounds); }
/**
* @param rounds number of rounds
* @note Currently only 8, 12 or 20 rounds are supported, all others
* will throw an exception
*/
explicit ChaCha(size_t rounds = 20);
std::string provider() const override;
void cipher(const uint8_t in[], uint8_t out[], size_t length) override;
void set_iv(const uint8_t iv[], size_t iv_len) override;
/*
* ChaCha accepts 0, 8, or 12 byte IVs. The default IV is a 8 zero bytes.
* An IV of length 0 is treated the same as the default zero IV.
*/
bool valid_iv_length(size_t iv_len) const override;
Key_Length_Specification key_spec() const override
{
return Key_Length_Specification(16, 32, 16);
}
void clear() override;
std::string name() const override;
void seek(uint64_t offset) override;
private:
void key_schedule(const uint8_t key[], size_t key_len) override;
void chacha_x4(uint8_t output[64*4], uint32_t state[16], size_t rounds);
#if defined(BOTAN_HAS_CHACHA_SSE2)
void chacha_sse2_x4(uint8_t output[64*4], uint32_t state[16], size_t rounds);
#endif
size_t m_rounds;
secure_vector<uint32_t> m_state;
secure_vector<uint8_t> m_buffer;
size_t m_position = 0;
};
}
#endif
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