/*
*  sha1.h
*
*  Copyright (C) 1998, 2009
*  Paul E. Jones <paulej@packetizer.com>
*  All Rights Reserved.
*
*****************************************************************************
*  $Id: sha1.h 12 2009-06-22 19:34:25Z paulej $
*****************************************************************************
*
*  Description:
*      This class implements the Secure Hashing Standard as defined
*      in FIPS PUB 180-1 published April 17, 1995.
*
*      Many of the variable names in this class, especially the single
*      character names, were used because those were the names used
*      in the publication.
*
*      Please read the file sha1.cpp for more information.
*
*/

#ifndef _SHA1_H_
#define _SHA1_H_

class SHA1
{
public:

	SHA1();
	virtual ~SHA1();

	/*
	*  Re-initialize the class
	*/
	void Reset();

	/*
	*  Returns the message digest
	*/
	bool Result(unsigned *message_digest_array);

	/*
	*  Provide input to SHA1
	*/
	void Input(const unsigned char *message_array,
		unsigned            length);
	void Input(const char  *message_array,
		unsigned    length);
	void Input(unsigned char message_element);
	void Input(char message_element);
	SHA1& operator<<(const char *message_array);
	SHA1& operator<<(const unsigned char *message_array);
	SHA1& operator<<(const char message_element);
	SHA1& operator<<(const unsigned char message_element);

private:

	/*
	*  Process the next 512 bits of the message
	*/
	void ProcessMessageBlock();

	/*
	*  Pads the current message block to 512 bits
	*/
	void PadMessage();

	/*
	*  Performs a circular left shift operation
	*/
	inline unsigned CircularShift(int bits, unsigned word);

	unsigned H[5];                      // Message digest buffers

	unsigned Length_Low;                // Message length in bits
	unsigned Length_High;               // Message length in bits

	unsigned char Message_Block[64];    // 512-bit message blocks
	int Message_Block_Index;            // Index into message block array

	bool Computed;                      // Is the digest computed?
	bool Corrupted;                     // Is the message digest corruped?

};


#endif // _SHA1_H_


