Visual C++ (Win32) で、SHA1 のハッシュ値を取得する方法

以下がサンプルコード。Win32 Crypto API を使うコンソールアプリです。

// HashTest.cpp : Defines the entry point for the console application.
// Copyright (c) 2005, 2006 twinkle.cc All Rights Reserved.
// https://perltips.twinkle.cc/
// perltips@gmail.com

#include "stdafx.h"
#include 
#include 
#include 

int _tmain(int argc, _TCHAR* argv[])
{
#define BUFFER_LEN 253
#define SHA1LEN  20

PCHAR    pcMessage;
DWORD    ccMessage;

DWORD dwStatus = 0;
HCRYPTPROV hProv = 0;
HCRYPTHASH hHash = 0;
BYTE pbHash[SHA1LEN];
BYTE pbRandom[BUFFER_LEN];
DWORD cbHash = 0;
CHAR pcDigits[] = "0123456789ABCDEF";
CHAR pcHash[SHA1LEN * 2 + 1];

//Get handle to the crypto provider
if (!CryptAcquireContext(&hProv,
    NULL,
    NULL,
    PROV_RSA_FULL,
    CRYPT_VERIFYCONTEXT))
{
    dwStatus = GetLastError();
    goto done;
}

// Get a random value
if( CryptGenRandom(
    hProv,
    BUFFER_LEN,
    pbRandom))
{
    printf("%d bytes of random data have been generated.\n", BUFFER_LEN);
}
else
{
    dwStatus = GetLastError();
    printf("Random bytes were not correctly generated.\n");
    goto done;
}

if (!CryptCreateHash(hProv, CALG_SHA1, 0, 0, &hHash))
{
    dwStatus = GetLastError();
    goto done;
}

if (!CryptHashData(hHash, pbRandom, BUFFER_LEN, 0))
{
    dwStatus = GetLastError();
    printf("CryptHashData failed: %d\n", dwStatus); 
    goto done;
}

cbHash = SHA1LEN;
if (CryptGetHashParam(hHash, HP_HASHVAL, pbHash, &cbHash, 0))
{
    printf("SHA1 hash is: ");
    for (DWORD i = 0; i < cbHash; i++)
    {
        pcHash[i * 2]      = pcDigits[pbHash[i] >> 4];
        pcHash[i * 2 + 1 ] = pcDigits[pbHash[i] & 0xf];
        pcHash[i * 2 + 2 ] = '\0';
    }
    printf("%s\n", pcHash);
}
else
{
    dwStatus = GetLastError();
    printf("CryptGetHashParam failed: %d\n", dwStatus); 
}

done:

CryptDestroyHash(hHash);
CryptReleaseContext(hProv, 0);

WCHAR pwcMessage[BUFFER_LEN];
MultiByteToWideChar(CP_ACP, 0, pcHash, sizeof(pcHash), pwcMessage, sizeof(pwcMessage));
   
ccMessage = ( DWORD ) wcslen( pwcMessage );

if( ( pcMessage = ( PCHAR ) malloc( ccMessage + 1 ) ) )
{
    WideCharToMultiByte( CP_ACP, 0, pwcMessage, -1, pcMessage, ccMessage + 1, NULL, NULL );
    printf("malloc ok: %s\n", pcMessage);
}
else
{
    printf("Not enough memory");
    dwStatus = ERROR_NOT_ENOUGH_MEMORY;
}

return dwStatus;
}