sha1.hpp

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/*
 *  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.
 *
 */

#pragma once
#include "noncopyable.hpp"

namespace acl
{

class sha1 : public noncopyable
{
public:
        sha1();
        virtual ~sha1();

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

        /*
         *  Returns the message digest, message_digest_array's length must >= 20
         */
        bool result(unsigned char *message_digest_array);
        bool result2(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 process_message_block();

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

        /*
         *  Performs a circular left shift operation
         */
        inline unsigned circular_shift(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?
};

} // namespace acl