Sha1.h

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/*
*       Sha1.h
*
*       Copyright (C) 1998
*       Paul E. Jones <paulej@acm.org>
*       All Rights Reserved.
*
*****************************************************************************
*       $Id: sha1.h,v 1.4 2001/03/20 06:25:06 paulej Exp $
*****************************************************************************
*
*       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