#ifndef SHA256_H
#define SHA256_H

class SHA256
{
  protected:
	typedef unsigned char uint8;
	typedef unsigned int uint32;
	typedef unsigned long long uint64;

	const static uint32 sha256_k[];
	static const unsigned int SHA224_256_BLOCK_SIZE = (512 / 8);

  public:
	void init();
	void update(const unsigned char* message, unsigned int len);
	void final(unsigned char* digest);
	static const unsigned int DIGEST_SIZE = (256 / 8);

  protected:
	void transform(const unsigned char* message, unsigned int block_nb);
	unsigned int m_tot_len;
	unsigned int m_len;
	unsigned char m_block[2 * SHA224_256_BLOCK_SIZE];
	uint32 m_h[8];
};

std::string sha256(std::string input);

#define SHA2_SHFR(x, n) (x >> n)
#define SHA2_ROTR(x, n) ((x >> n) | (x << ((sizeof(x) << 3) - n)))
#define SHA2_ROTL(x, n) ((x << n) | (x >> ((sizeof(x) << 3) - n)))
#define SHA2_CH(x, y, z) ((x & y) ^ (~x & z))
#define SHA2_MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
#define SHA256_F1(x) (SHA2_ROTR(x, 2) ^ SHA2_ROTR(x, 13) ^ SHA2_ROTR(x, 22))
#define SHA256_F2(x) (SHA2_ROTR(x, 6) ^ SHA2_ROTR(x, 11) ^ SHA2_ROTR(x, 25))
#define SHA256_F3(x) (SHA2_ROTR(x, 7) ^ SHA2_ROTR(x, 18) ^ SHA2_SHFR(x, 3))
#define SHA256_F4(x) (SHA2_ROTR(x, 17) ^ SHA2_ROTR(x, 19) ^ SHA2_SHFR(x, 10))
#define SHA2_UNPACK32(x, str)                                                                                                              \
	{                                                                                                                                      \
		*((str) + 3) = (uint8)((x));                                                                                                       \
		*((str) + 2) = (uint8)((x) >> 8);                                                                                                  \
		*((str) + 1) = (uint8)((x) >> 16);                                                                                                 \
		*((str) + 0) = (uint8)((x) >> 24);                                                                                                 \
	}
#define SHA2_PACK32(str, x)                                                                                                                \
	{                                                                                                                                      \
		*(x) = ((uint32) * ((str) + 3)) | ((uint32) * ((str) + 2) << 8) | ((uint32) * ((str) + 1) << 16) | ((uint32) * ((str) + 0) << 24); \
	}
#endif