Invalid Algorithm Specified CryptoAPI

Question

I am trying to decrypt something using 128BIT AES Decryption. When i attempt to calling CryptDecrypt i get an Error stating "Invalid Algorithm Specified". I get the same problem when using the library posted here: http://www.codeproject.com/KB/security/WinAES.aspx

What can cause this error?

I am using CryptoAPI along on vista64bit with visual studio 2008. I checked in the registry and the AES library is there...

EDIT

BYTE*& encryptedData /*  get data length */
HCRYPTPROV cryptoHandle = NULL;
HCRYPTKEY aesKeyHandle = NULL;

hr = InitWinCrypt(cryptoHandle);
if(FAILED(hr))
{
    return hr;
}

AesKeyOffering aesKey = { {PLAINTEXTKEYBLOB, CUR_BLOB_VERSION, 0, CALG_AES_128}, 16, { 0xFF, 0x00, 0xFF, 0x1C, 0x1D, 0x1E, 0x03, 0x04, 0x05, 0x0F, 0x20, 0x21, 0xAD, 0xAF, 0xA4, 0x04 }};

if(CryptImportKey(cryptoHandle, (CONST BYTE*)&aesKey, sizeof(AesKeyOffering), NULL, 0, &aesKeyHandle) == FALSE)
{
    // DO error

    return HRESULT_FROM_WIN32(GetLastError());
}

if(CryptSetKeyParam(aesKeyHandle, KP_IV, { 0xFF, 0x00, 0xFF, 0x1C, 0x1D, 0x1E, 0x03, 0x04, 0x05, 0x0F, 0x20, 0x21, 0xAD, 0xAF, 0xA4, 0x04 } , 0) == FALSE)
{
    return HRESULT_FROM_WIN32(GetLastError());
}

BYTE blah2 = CRYPT_MODE_CBC;
// set block mode
if(CryptSetKeyParam(aesKeyHandle, KP_MODE, &blah2, 0) == FALSE)
{
    // 

    return HRESULT_FROM_WIN32(GetLastError());
}

DWORD lol = dataLength / 16 + 1;
DWORD lol2 = lol * 16;
if(CryptDecrypt(aesKeyHandle, 0, TRUE, 0, encryptedData, &lol2) == FALSE)
{
    return HRESULT_FROM_WIN32(GetLastError());
}

InitWinCrypt function

    if(!CryptAcquireContextW(&cryptoHandle, NULL, L"Microsoft Enhanced RSA and AES Cryptographic Provider", PROV_RSA_AES, CRYPT_VERIFYCONTEXT))
{
    if(!CryptAcquireContextW(&cryptoHandle, NULL, L"Microsoft Enhanced RSA and AES Cryptographic Provider", PROV_RSA_AES, 0))
    {
        return HRESULT_FROM_WIN32(GetLastError());
    }
    else
    {
        return S_OK;
    }
}
return S_OK;

AesOffering struct:

struct AesKeyOffering
{
    BLOBHEADER m_Header;
    DWORD m_KeyLength;
    BYTE Key[16];
};

EDIT2

After rebooting my computer, and remvoing the CBC chunk. I am now getting Bad Data Errors. The data decrypts fine in C#. But i need to do this using wincrypt.

Answer 1

Are you passing cryptoHandle by reference to InitWithCrypt? If not, your code

if(!CryptAcquireContextW(&cryptoHandle, ...

would only modify InitWinCrypt's copy of cryptoHandle.

---

EDIT: Given that it does, try getting rid of the CryptSetKeyParam call which sets CRYPT_MODE_CBC