Sha256.h

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/* Sha256.h -- SHA-256 Hash
: Igor Pavlov : Public domain */
 
#ifndef ZIP7_INC_SHA256_H
#define ZIP7_INC_SHA256_H
 
#include "7zTypes.h"
 
EXTERN_C_BEGIN
 
#define SHA256_NUM_BLOCK_WORDS  16
#define SHA256_NUM_DIGEST_WORDS  8
 
#define SHA256_BLOCK_SIZE   (SHA256_NUM_BLOCK_WORDS * 4)
#define SHA256_DIGEST_SIZE  (SHA256_NUM_DIGEST_WORDS * 4)
 
 
 
 
typedef void (Z7_FASTCALL *SHA256_FUNC_UPDATE_BLOCKS)(UInt32 state[8], const Byte *data, size_t numBlocks);
 
/*
  if (the system supports different SHA256 code implementations)
  {
    (CSha256::func_UpdateBlocks) will be used
    (CSha256::func_UpdateBlocks) can be set by
       Sha256_Init()        - to default (fastest)
       Sha256_SetFunction() - to any algo
  }
  else
  {
    (CSha256::func_UpdateBlocks) is ignored.
  }
*/
 
typedef struct
{
  union
  {
    struct
    {
      SHA256_FUNC_UPDATE_BLOCKS func_UpdateBlocks;
      UInt64 count;
    } vars;
    UInt64 _pad_64bit[4];
    void *_pad_align_ptr[2];
  } v;
  UInt32 state[SHA256_NUM_DIGEST_WORDS];
 
  Byte buffer[SHA256_BLOCK_SIZE];
} CSha256;
 
 
#define SHA256_ALGO_DEFAULT 0
#define SHA256_ALGO_SW      1
#define SHA256_ALGO_HW      2
 
/*
Sha256_SetFunction()
return:
  0 - (algo) value is not supported, and func_UpdateBlocks was not changed
  1 - func_UpdateBlocks was set according (algo) value.
*/
 
BoolInt Sha256_SetFunction(CSha256 *p, unsigned algo);
 
void Sha256_InitState(CSha256 *p);
void Sha256_Init(CSha256 *p);
void Sha256_Update(CSha256 *p, const Byte *data, size_t size);
void Sha256_Final(CSha256 *p, Byte *digest);
 
 
 
 
// void Z7_FASTCALL Sha256_UpdateBlocks(UInt32 state[8], const Byte *data, size_t numBlocks);
 
/*
call Sha256Prepare() once at program start.
It prepares all supported implementations, and detects the fastest implementation.
*/
 
void Sha256Prepare(void);
 
EXTERN_C_END
 
#endif