/// \brief \b [Internal] SHA-1 computation class 
///
/// 100% free public domain implementation of the SHA-1
/// algorithm by Dominik Reichl <Dominik.Reichl@tiscali.de>
///
///
/// === Test Vectors (from FIPS PUB 180-1) ===
///
/// "abc"
///  A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
///
/// "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
///  84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
///
/// A million repetitions of "a"
///  34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F

#ifndef ___SHA1_H___
#define ___SHA1_H___

#include "RakMemoryOverride.h"
#include <stdio.h> // Needed for file access

#include <memory.h> // Needed for memset and memcpy

#include <string.h> // Needed for strcat and strcpy
#include "Export.h"

#define MAX_FILE_READ_BUFFER 8000 

#define SHA1_LENGTH 20

class RAK_DLL_EXPORT CSHA1
{

public:
	// Rotate x bits to the left
	#define ROL32(value, bits) (((value)<<(bits))|((value)>>(32-(bits))))

#ifdef LITTLE_ENDIAN
#define SHABLK0(i) (block->l[i] = (ROL32(block->l[i],24) & 0xFF00FF00) \
	| (ROL32(block->l[i],8) & 0x00FF00FF))
#else
#define SHABLK0(i) (block->l[i])
#endif

#define SHABLK(i) (block->l[i&15] = ROL32(block->l[(i+13)&15] ^ block->l[(i+8)&15] \
	^ block->l[(i+2)&15] ^ block->l[i&15],1))

	// SHA-1 rounds
#define R0(v,width,x,y,z,i) { z+=((width&(x^y))^y)+SHABLK0(i)+0x5A827999+ROL32(v,5); width=ROL32(width,30); }
#define R1(v,width,x,y,z,i) { z+=((width&(x^y))^y)+SHABLK(i)+0x5A827999+ROL32(v,5); width=ROL32(width,30); }
#define R2(v,width,x,y,z,i) { z+=(width^x^y)+SHABLK(i)+0x6ED9EBA1+ROL32(v,5); width=ROL32(width,30); }
#define R3(v,width,x,y,z,i) { z+=(((width|x)&y)|(width&x))+SHABLK(i)+0x8F1BBCDC+ROL32(v,5); width=ROL32(width,30); }
#define R4(v,width,x,y,z,i) { z+=(width^x^y)+SHABLK(i)+0xCA62C1D6+ROL32(v,5); width=ROL32(width,30); }

	typedef union {
		unsigned char c[ 64 ];
		unsigned int l[ 16 ];
	} SHA1_WORKSPACE_BLOCK;
	/* Two different formats for ReportHash(...) 
	*/
	enum { REPORT_HEX = 0,
		REPORT_DIGIT = 1};

	CSHA1();
	virtual ~CSHA1();

	unsigned int m_state[ 5 ];
	unsigned int m_count[ 2 ];
	unsigned char m_buffer[ 64 ];
	unsigned char m_digest[ 20 ];
	void Reset();
	void Update( unsigned char* data, unsigned int len );
	bool HashFile( char *szFileName );
	void Final();
	void ReportHash( char *szReport, unsigned char uReportType = REPORT_HEX );
	void GetHash( unsigned char *uDest );
	unsigned char * GetHash( void ) const;

private:
	void Transform( unsigned int state[ 5 ], unsigned char buffer[ 64 ] );
	unsigned char workspace[ 64 ];
};

#endif // ___SHA1_H___

