/*
	100% free public domain implementation of the SHA-1 algorithm
	by Dominik Reichl <dominik.reichl@t-online.de>
	Web: http://www.dominik-reichl.de/

	Version 1.8 - 2008-03-16
	- Converted project files to Visual Studio 2008 format.
	- Added Unicode support for HashFile utility method.
	- Added support for hashing files using the HashFile method that are
	  larger than 2 GB.
	- HashFile now returns an error code instead of copying an error
	  message into the output buffer.
	- GetHash now returns an error code and validates the input parameter.
	- Added ReportHashStl STL utility method.
	- Added REPORT_HEX_SHORT reporting mode.
	- Improved Linux compatibility of test program.

	Version 1.7 - 2006-12-21
	- Fixed buffer underrun warning that appeared when compiling with
	  Borland C Builder (thanks to Rex Bloom and Tim Gallagher for the
	  patch).
	- Breaking change: ReportHash writes the final hash to the start
	  of the buffer, i.e. it's not appending it to the string anymore.
	- Made some function parameters const.
	- Added Visual Studio 2005 project files to demo project.

	Version 1.6 - 2005-02-07 (thanks to Howard Kapustein for patches)
	- You can set the endianness in your files, no need to modify the
	  header file of the CSHA1 class anymore.
	- Aligned data support.
	- Made support/compilation of the utility functions (ReportHash and
	  HashFile) optional (useful when bytes count, for example in embedded
	  environments).

	Version 1.5 - 2005-01-01
	- 64-bit compiler compatibility added.
	- Made variable wiping optional (define SHA1_WIPE_VARIABLES).
	- Removed unnecessary variable initializations.
	- ROL32 improvement for the Microsoft compiler (using _rotl).

	Version 1.4 - 2004-07-22
	- CSHA1 now compiles fine with GCC 3.3 under MacOS X  (thanks to Larry
	  Hastings).

	Version 1.3 - 2003-08-17
	- Fixed a small memory bug and made a buffer array a class member to
	  ensure correct working when using multiple CSHA1 class instances at
	  one time.

	Version 1.2 - 2002-11-16
	- Borlands C++ compiler seems to have problems with string addition
	  using sprintf. Fixed the bug which caused the digest report function
	  not to work properly. CSHA1 is now Borland compatible.

	Version 1.1 - 2002-10-11
	- Removed two unnecessary header file includes and changed BOOL to
	  bool. Fixed some minor bugs in the web page contents.

	Version 1.0 - 2002-06-20
	- First official release.

	======== Test Vectors (from FIPS PUB 180-1) ========

	SHA1("abc") =
		A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D

	SHA1("abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq") =
		84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1

	SHA1(A million repetitions of "a") =
		34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
*/
// clang-format off

#ifndef ___SHA1_HDR___
#define ___SHA1_HDR___

#include <climits>

#include <OpenImageIO/export.h>
#include <OpenImageIO/oiioversion.h>
#include <OpenImageIO/platform.h>

#if !defined(SHA1_UTILITY_FUNCTIONS) && !defined(SHA1_NO_UTILITY_FUNCTIONS)
#define SHA1_UTILITY_FUNCTIONS
#endif

#if !defined(SHA1_STL_FUNCTIONS) && !defined(SHA1_NO_STL_FUNCTIONS)
#define SHA1_STL_FUNCTIONS
#if !defined(SHA1_UTILITY_FUNCTIONS)
#error STL functions require SHA1_UTILITY_FUNCTIONS.
#endif
#endif

#include <memory.h>

#ifdef SHA1_UTILITY_FUNCTIONS
#include <cstdio>
#include <cstring>
#endif

#ifdef SHA1_STL_FUNCTIONS
#include <string>
#endif

#ifdef _MSC_VER
#include <stdlib.h>
#endif

// You can define the endian mode in your files without modifying the SHA-1
// source files. Just #define SHA1_LITTLE_ENDIAN or #define SHA1_BIG_ENDIAN
// in your files, before including the SHA1.h header file. If you don't
// define anything, the class defaults to little endian.
#if !defined(SHA1_LITTLE_ENDIAN) && !defined(SHA1_BIG_ENDIAN)
#define SHA1_LITTLE_ENDIAN
#endif

// If you want variable wiping, #define SHA1_WIPE_VARIABLES, if not,
// #define SHA1_NO_WIPE_VARIABLES. If you don't define anything, it
// defaults to wiping.
#if !defined(SHA1_WIPE_VARIABLES) && !defined(SHA1_NO_WIPE_VARIABLES)
#define SHA1_WIPE_VARIABLES
#endif

#ifdef _MSC_VER
#define _sntprintf std::snprintf
#else
#define _sntprintf std::snprintf
#endif

// Fallback, if no 64-bit support
#ifndef _fseeki64
#define _fseeki64 fseek
#endif
#ifndef _ftelli64
#define _ftelli64 ftell
#endif

///////////////////////////////////////////////////////////////////////////
// Define variable types

#define UINT_8  uint8_t
#define UINT_32 uint32_t
#define UINT_64 uint64_t
#define INT_64  int64_t


///////////////////////////////////////////////////////////////////////////
// Declare SHA-1 workspace

OIIO_NAMESPACE_BEGIN

typedef union
{
	UINT_8 c[64];
	UINT_32 l[16];
} SHA1_WORKSPACE_BLOCK;

class CSHA1
{
public:
#ifdef SHA1_UTILITY_FUNCTIONS
	// Different formats for ReportHash
	enum REPORT_TYPE
	{
		REPORT_HEX = 0,
		REPORT_DIGIT = 1,
		REPORT_HEX_SHORT = 2
	};
#endif

	// Constructor and destructor
	CSHA1();
	~CSHA1();

	UINT_32 m_state[5];
	UINT_32 m_count[2];
	UINT_32 m_reserved0[1]; // Memory alignment padding
	UINT_8 m_buffer[64];
	UINT_8 m_digest[20];
	UINT_32 m_reserved1[3]; // Memory alignment padding

	void Reset();

	// Update the hash value
	void Update(const UINT_8* pbData, UINT_32 uLen);

#ifdef SHA1_UTILITY_FUNCTIONS
	// Hash in file contents
	bool HashFile(const char* szFileName);
#endif

	// Finalize hash, call before using ReportHash(Stl)
	void Final();

#ifdef SHA1_UTILITY_FUNCTIONS
	bool ReportHash(char* szReport, REPORT_TYPE rtReportType = REPORT_HEX) const;
#endif

#ifdef SHA1_STL_FUNCTIONS
	bool ReportHashStl(std::string& strOut, REPORT_TYPE rtReportType =
		REPORT_HEX) const;
#endif

	bool GetHash(UINT_8* pbDest) const;

private:
	// Private SHA-1 transformation
	void Transform(UINT_32* pState, const UINT_8* pBuffer);

	// Member variables
	UINT_8 m_workspace[64];
	SHA1_WORKSPACE_BLOCK* m_block; // SHA1 pointer to the byte array above
};

OIIO_NAMESPACE_END

#endif // ___SHA1_HDR___