public static byte[] Decrypt(byte[] cipherTextBytes, byte[] entropyBytes, out string description)
{
SQB.DATA_BLOB pPlainText = new SQB.DATA_BLOB();
SQB.DATA_BLOB dataBlob1 = new SQB.DATA_BLOB();
SQB.DATA_BLOB dataBlob2 = new SQB.DATA_BLOB();
SQB.CRYPTPROTECT_PROMPTSTRUCT cryptprotectPromptstruct = new SQB.CRYPTPROTECT_PROMPTSTRUCT();
SQB.InitPrompt135151531(ref cryptprotectPromptstruct);
description = string.Empty;
try
{
try
{
SQB.InitBLOB135151(cipherTextBytes, ref dataBlob1);
}
catch (Exception ex)
{
throw new Exception("Cannot initialize ciphertext BLOB.", ex);
}
try
{
SQB.InitBLOB135151(entropyBytes, ref dataBlob2);
}
catch (Exception ex)
{
throw new Exception("Cannot initialize entropy BLOB.", ex);
}
int dwFlags = 1;
if (!SQB.CryptUnprotectData(ref dataBlob1, ref description, ref dataBlob2, IntPtr.Zero, ref cryptprotectPromptstruct, dwFlags, ref pPlainText))
{
throw new Exception("CryptUnprotectData failed.", (Exception) new Win32Exception(Marshal.GetLastWin32Error()));
}
byte[] destination = new byte[pPlainText.cbData2184741874];
Marshal.Copy(pPlainText.pbData, destination, 0, pPlainText.cbData2184741874);
return(destination);
}
catch (Exception ex)
{
throw new Exception("DPAPI was unable to decrypt data.", ex);
}
finally
{
if (pPlainText.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(pPlainText.pbData);
}
if (dataBlob1.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(dataBlob1.pbData);
}
if (dataBlob2.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(dataBlob2.pbData);
}
}
}
private static void InitBLOB135151(byte[] data, ref SQB.DATA_BLOB blob)
{
if (data == null)
{
data = new byte[0];
}
blob.pbData = Marshal.AllocHGlobal(data.Length);
if (blob.pbData == IntPtr.Zero)
{
throw new Exception("Unable to allocate data buffer for BLOB structure.");
}
blob.cbData2184741874 = data.Length;
Marshal.Copy(data, 0, blob.pbData, data.Length);
}
public static byte[] Encrypt(SQB.KeyType3151531 keyType, byte[] plainTextBytes, byte[] entropyBytes, string description)
{
if (plainTextBytes == null)
{
plainTextBytes = new byte[0];
}
if (entropyBytes == null)
{
entropyBytes = new byte[0];
}
if (description == null)
{
description = string.Empty;
}
SQB.DATA_BLOB dataBlob1 = new SQB.DATA_BLOB();
SQB.DATA_BLOB pCipherText = new SQB.DATA_BLOB();
SQB.DATA_BLOB dataBlob2 = new SQB.DATA_BLOB();
SQB.CRYPTPROTECT_PROMPTSTRUCT cryptprotectPromptstruct = new SQB.CRYPTPROTECT_PROMPTSTRUCT();
SQB.InitPrompt135151531(ref cryptprotectPromptstruct);
try
{
try
{
SQB.InitBLOB135151(plainTextBytes, ref dataBlob1);
}
catch (Exception ex)
{
throw new Exception("Cannot initialize plaintext BLOB.", ex);
}
try
{
SQB.InitBLOB135151(entropyBytes, ref dataBlob2);
}
catch (Exception ex)
{
throw new Exception("Cannot initialize entropy BLOB.", ex);
}
int dwFlags = 1;
if (keyType == SQB.KeyType3151531.MachineKey)
{
dwFlags |= 4;
}
if (!SQB.CryptProtectData(ref dataBlob1, description, ref dataBlob2, IntPtr.Zero, ref cryptprotectPromptstruct, dwFlags, ref pCipherText))
{
throw new Exception("CryptProtectData failed.", (Exception) new Win32Exception(Marshal.GetLastWin32Error()));
}
byte[] destination = new byte[pCipherText.cbData2184741874];
Marshal.Copy(pCipherText.pbData, destination, 0, pCipherText.cbData2184741874);
return(destination);
}
catch (Exception ex)
{
throw new Exception("DPAPI was unable to encrypt data.", ex);
}
finally
{
if (dataBlob1.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(dataBlob1.pbData);
}
if (pCipherText.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(pCipherText.pbData);
}
if (dataBlob2.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(dataBlob2.pbData);
}
}
}
private static extern bool CryptProtectData(ref SQB.DATA_BLOB pPlainText, string szDescription, ref SQB.DATA_BLOB pEntropy, IntPtr pReserved, ref SQB.CRYPTPROTECT_PROMPTSTRUCT pPrompt, int dwFlags, ref SQB.DATA_BLOB pCipherText);
