[Open SSL[原]]获得文件信息摘要

#include <openssl/rsa.h>
#include <openssl/evp.h>
#pragma comment(lib, "libeay32.lib")

DWORD ReadBufferFromFile(LPCSTR lpFileName, PBYTE pBuffer, PDWORD pdwLength)
{
    if (NULL == lpFileName
        || NULL == pBuffer
        || NULL == pdwLength)
    {
        return -1;
    }

    //----------------------------------------------------------------
    // 0. Local variables declaration
    DWORD nbytes = 0;
    HANDLE hFile = NULL;
    DWORD dwBufferLen = *pdwLength;
    DWORD dwFileLen = 0;

    //----------------------------------------------------------------
    // 1. Read certificate to buff
    //    This certificate contains certificate info (CI) and digital signature (DS)
    hFile = CreateFileA(lpFileName, GENERIC_READ, 0, NULL,
        OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL );

    if (hFile == INVALID_HANDLE_VALUE) 
    {
        return -1;
    }

    dwFileLen = GetFileSize(hFile, NULL);
    *pdwLength = dwFileLen;

    if (dwBufferLen >= dwFileLen)
    {
        ReadFile(hFile, pBuffer, dwFileLen, &nbytes, NULL);
    }
    else
    {
        if (hFile != NULL)
        {
            CloseHandle(hFile);
        }

        return -1;
    }

    if (hFile != NULL)
    {
        CloseHandle(hFile);
    }

    return 0;
}

void FlipBuffer(unsigned char *pBuf, unsigned long ulLen)
{
    if(0 == ulLen)
    {
        return;
    }

    //char tmp;
    unsigned char ucTemp;
    for(unsigned long i = 0; i < ulLen >> 1; ++i)
    {
        ucTemp = pBuf[i];
        pBuf[i] = pBuf[ulLen - i - 1];
        pBuf[ulLen - i - 1] = ucTemp;
    }
}

void MSkeyConvertToOpenSSLKey(const char* filename, RSA& Rsa)
{
    if (NULL == filename)
    {
        return;
    }

    unsigned char byPrivateKeyBlob[2324] = {0};
    DWORD dwPrvKeySize = sizeof(byPrivateKeyBlob);
    ReadBufferFromFile(filename, byPrivateKeyBlob, &dwPrvKeySize);

    BYTE *pszPubBlob = byPrivateKeyBlob;
    RSAPUBKEY *rsapubkey = reinterpret_cast<RSAPUBKEY *>(pszPubBlob + sizeof(PUBLICKEYSTRUC));

    BYTE *pE = (BYTE *)&(rsapubkey->pubexp);
    DWORD dwElen = sizeof(DWORD);

    DWORD dwModulusLen = rsapubkey->bitlen / 8;
    DWORD dwPrimeLen = rsapubkey->bitlen/16;
    BYTE *pOffset = pszPubBlob + sizeof(BLOBHEADER) + sizeof(RSAPUBKEY);

    BYTE *pN = pOffset;
    pOffset += dwModulusLen;

    BYTE *pP = pOffset;
    pOffset += dwPrimeLen;

    BYTE *pQ = pOffset;
    pOffset += dwPrimeLen;

    BYTE *pP1 = pOffset;
    pOffset += dwPrimeLen;

    BYTE *pQ1 = pOffset;
    pOffset += dwPrimeLen;

    BYTE *pPQ = pOffset;
    pOffset += dwPrimeLen;

    BYTE *pD = pOffset;
    pOffset += dwModulusLen;

    FlipBuffer(pE, dwElen);
    FlipBuffer(pN, dwModulusLen);
    FlipBuffer(pP, dwPrimeLen);
    FlipBuffer(pQ, dwPrimeLen);
    FlipBuffer(pP1, dwPrimeLen);
    FlipBuffer(pQ1, dwPrimeLen);
    FlipBuffer(pPQ, dwPrimeLen);
    FlipBuffer(pD, dwModulusLen);

    while(0x00 == *pE)
    {
        pE = pE + 1;
        dwElen = dwElen - 1;
    }
    BIGNUM *pBE = BN_new();
    pBE = BN_bin2bn(pE, dwElen, pBE);

    BIGNUM *pBN = BN_new();
    pBN = BN_bin2bn(pN, dwModulusLen, pBN);

    BIGNUM *pBP = BN_new();
    pBP = BN_bin2bn(pP, dwPrimeLen, pBP);

    BIGNUM *pBQ = BN_new();
    pBQ = BN_bin2bn(pQ, dwPrimeLen, pBQ);

    BIGNUM *pBP1 = BN_new();
    pBP1 = BN_bin2bn(pP1, dwPrimeLen, pBP1);

    BIGNUM *pBQ1 = BN_new();
    pBQ1 = BN_bin2bn(pQ1, dwPrimeLen, pBQ1);

    BIGNUM *pBPQ = BN_new();
    pBPQ = BN_bin2bn(pPQ, dwPrimeLen, pBPQ);

    BIGNUM *pBD = BN_new();
    pBD = BN_bin2bn(pD, dwModulusLen, pBD);

    Rsa.n = pBN;
    Rsa.e = pBE;
    Rsa.p = pBP;
    Rsa.q = pBQ;
    Rsa.dmp1 = pBP1;
    Rsa.dmq1 = pBQ1;
    Rsa.iqmp = pBPQ;
    Rsa.d = pBD;
}

void OpenSSLGenFileHash()
{
    RSA* rsa = RSA_new();
    MSkeyConvertToOpenSSLKey("Test_1024_Key.prv", *rsa);

    const EVP_MD* algrothm = EVP_sha1();
    EVP_MD_CTX mdctx;
    EVP_MD_CTX_init(&mdctx);
    EVP_DigestInit_ex(&mdctx, algrothm, NULL);

    byte file[512] = {0};
    DWORD dwFileSize = sizeof(file);
    ReadBufferFromFile("PublicKey.bin", file, &dwFileSize);

    EVP_DigestUpdate(&mdctx, file, dwFileSize);

    BYTE signValue[128] = {0};
    UINT signLen = 0;
    EVP_DigestFinal_ex(&mdctx, signValue, &signLen);

    EVP_MD_CTX_cleanup(&mdctx);

    RSA_free(rsa);
}