nastools_zerotierone/node/Salsa20.hpp
2016-11-01 16:45:16 -07:00

116 lines
2.1 KiB
C++

/*
* Based on public domain code available at: http://cr.yp.to/snuffle.html
*
* This therefore is public domain.
*/
#ifndef ZT_SALSA20_HPP
#define ZT_SALSA20_HPP
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include "Constants.hpp"
#include "Utils.hpp"
#if (!defined(ZT_SALSA20_SSE)) && (defined(__SSE2__) || defined(__WINDOWS__))
#define ZT_SALSA20_SSE 1
#endif
#ifdef ZT_SALSA20_SSE
#include <emmintrin.h>
#endif // ZT_SALSA20_SSE
namespace ZeroTier {
/**
* Salsa20 stream cipher
*/
class Salsa20
{
public:
Salsa20() throw() {}
~Salsa20() { Utils::burn(&_state,sizeof(_state)); }
/**
* @param key Key bits
* @param kbits Number of key bits: 128 or 256 (recommended)
* @param iv 64-bit initialization vector
*/
Salsa20(const void *key,unsigned int kbits,const void *iv)
throw()
{
init(key,kbits,iv);
}
/**
* Initialize cipher
*
* @param key Key bits
* @param kbits Number of key bits: 128 or 256 (recommended)
* @param iv 64-bit initialization vector
*/
void init(const void *key,unsigned int kbits,const void *iv)
throw();
/**
* Encrypt data using Salsa20/12
*
* @param in Input data
* @param out Output buffer
* @param bytes Length of data
*/
void encrypt12(const void *in,void *out,unsigned int bytes)
throw();
/**
* Encrypt data using Salsa20/20
*
* @param in Input data
* @param out Output buffer
* @param bytes Length of data
*/
void encrypt20(const void *in,void *out,unsigned int bytes)
throw();
/**
* Decrypt data
*
* @param in Input data
* @param out Output buffer
* @param bytes Length of data
*/
inline void decrypt12(const void *in,void *out,unsigned int bytes)
throw()
{
encrypt12(in,out,bytes);
}
/**
* Decrypt data
*
* @param in Input data
* @param out Output buffer
* @param bytes Length of data
*/
inline void decrypt20(const void *in,void *out,unsigned int bytes)
throw()
{
encrypt20(in,out,bytes);
}
private:
union {
#ifdef ZT_SALSA20_SSE
__m128i v[4];
#endif // ZT_SALSA20_SSE
uint32_t i[16];
} _state;
};
} // namespace ZeroTier
#endif