Error occurred while decoding OAEP padding

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C#

Hi all,

I have developed a web service that encrypts a connection string and passes back the encrypted string to a console application (test purposes).

The web service runs on a different PC than the console application. But I keep receiving the following exception message: Error occurred while decoding OAEP padding.

When I run the encrypt and decrypt code on the same PC everything works just fine?!?! Both the web service and the console application makes use of the same KeyContainerName.

Encryption Method:

private static string EncryptString(string inputString, int dwKeySize, string keyContainerName)
{
    // TODO: Add Proper Exception Handlers
    CspParameters cspParams = new CspParameters();
    cspParams.KeyContainerName = keyContainerName;
    RSACryptoServiceProvider rsaCryptoServiceProvider = new RSACryptoServiceProvider(dwKeySize, cspParams);
    //rsaCryptoServiceProvider.FromXmlString(xmlString);
    int keySize = dwKeySize / 8;
    byte[] bytes = Encoding.UTF32.GetBytes(inputString);
    // The hash function in use by the .NET RSACryptoServiceProvider here
    // is SHA1
    // int maxLength = ( keySize ) - 2 -
    //              ( 2 * SHA1.Create().ComputeHash( rawBytes ).Length );
    int maxLength = keySize - 42;
    int dataLength = bytes.Length;
    int iterations = dataLength / maxLength;
    StringBuilder stringBuilder = new StringBuilder();
    for (int i = 0; i <= iterations; i++)
    {
        byte[] tempBytes = new byte[(dataLength - maxLength * i > maxLength) ? maxLength : dataLength - maxLength * i];
        Buffer.BlockCopy(bytes, maxLength * i, tempBytes, 0, tempBytes.Length);
        byte[] encryptedBytes = rsaCryptoServiceProvider.Encrypt(tempBytes, true);
        // Be aware the RSACryptoServiceProvider reverses the order of
        // encrypted bytes. It does this after encryption and before
        // decryption. If you do not require compatibility with Microsoft
        // Cryptographic API (CAPI) and/or other vendors. Comment out the
        // next line and the corresponding one in the DecryptString function.
        //Array.Reverse(encryptedBytes);
        // Why convert to base 64?
        // Because it is the largest power-of-two base printable using only
        // ASCII characters
        stringBuilder.Append(Convert.ToBase64String(encryptedBytes));
    }
    return stringBuilder.ToString();
}

Decryption Method:

private static string DecryptString(string inputString, int dwKeySize, string keyContainerName)
{
    // TODO: Add Proper Exception Handlers
    CspParameters cspParams = new CspParameters();
    cspParams.KeyContainerName = keyContainerName;
    RSACryptoServiceProvider rsaCryptoServiceProvider = new RSACryptoServiceProvider(dwKeySize, cspParams);
    int base64BlockSize = ((dwKeySize / 8) % 3 != 0) ? (((dwKeySize / 8) / 3) * 4) + 4 : ((dwKeySize / 8) / 3) * 4;
    int iterations = inputString.Length / base64BlockSize;
    ArrayList arrayList = new ArrayList();
    for (int i = 0; i < iterations; i++)
    {
        byte[] encryptedBytes = Convert.FromBase64String(inputString.Substring(base64BlockSize * i, base64BlockSize));
        // Be aware the RSACryptoServiceProvider reverses the order of
        // encrypted bytes after encryption and before decryption.
        // If you do not require compatibility with Microsoft Cryptographic
        // API (CAPI) and/or other vendors.
        // Comment out the next line and the corresponding one in the
        // EncryptString function.
        Array.Reverse(encryptedBytes);
        arrayList.AddRange(rsaCryptoServiceProvider.Decrypt(encryptedBytes, true));
    }
    return Encoding.UTF32.GetString(arrayList.ToArray(Type.GetType("System.Byte")) as byte[]);
}

Can anyone please assist me in the matter?
Many thanks in advance.
Kind regards,