text: // Copyright (c) 2014 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef BITCOIN_CRYPTO_SHA256_H
  #define BITCOIN_CRYPTO_SHA256_H
  
  #include <stdint.h>
  #include <stdlib.h>
  
  /** A hasher class for SHA-256. */
  class CSHA256
  {
  private:
  	uint32_t s[8];
  	unsigned char buf[64];
  	uint64_t bytes;
  
  public:
  	static const size_t OUTPUT_SIZE = 32;
  
  	CSHA256();
  	CSHA256 &Write(const unsigned char *data, size_t len);
  	void Finalize(unsigned char hash[OUTPUT_SIZE]);
  	CSHA256 &Reset();
  };
  
  #endif // BITCOIN_CRYPTO_SHA256_H
  