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 POPBIT_CRYPTO_SHA1_H
  #define POPBIT_CRYPTO_SHA1_H
  
  #include <stdint.h>
  #include <stdlib.h>
  
  /** A hasher class for SHA1. */
  class CSHA1
  {
  private:
      uint32_t s[5];
      unsigned char buf[64];
      size_t bytes;
  
  public:
      static const size_t OUTPUT_SIZE = 20;
  
      CSHA1();
      CSHA1& Write(const unsigned char* data, size_t len);
      void Finalize(unsigned char hash[OUTPUT_SIZE]);
      CSHA1& Reset();
  };
  
  #endif // POPBIT_CRYPTO_SHA1_H
  