public static bool CryptCreateHash(
                SafeProvHandle hProv,
                int algId,
                SafeKeyHandle hKey,
                CryptCreateHashFlags dwFlags,
                out SafeHashHandle phHash)
            {
                bool response = _CryptCreateHash(hProv, algId, hKey, dwFlags, out phHash);

                phHash.SetParent(hProv);

                return response;
            }

 public static extern bool CryptVerifySignature(SafeHashHandle hHash, byte[] pbSignature, int dwSigLen, SafeKeyHandle hPubKey, String sDescription, CryptSignAndVerifyHashFlags dwFlags);

 public static extern bool CryptSignHash(SafeHashHandle hHash, KeySpec dwKeySpec, String sDescription, CryptSignAndVerifyHashFlags dwFlags, [Out] byte[] pbSignature, [In, Out] ref int pdwSigLen);

 public static extern bool CryptSetHashParam(SafeHashHandle hHash, CryptHashProperty dwParam, byte[] buffer, int dwFlags);

 public static extern bool CryptGetHashParam(SafeHashHandle hHash, CryptHashProperty dwParam, out int pbData, [In, Out] ref int pdwDataLen, int dwFlags);

 private static extern bool _CryptCreateHash(SafeProvHandle hProv, int algId, SafeKeyHandle hKey, CryptCreateHashFlags dwFlags, out SafeHashHandle phHash);

 public static extern NTSTATUS BCryptHashData(
     SafeHashHandle hHash,
     byte[] pbInput,
     int cbInput,
     BCryptHashDataFlags dwFlags = BCryptHashDataFlags.None);

            public static bool CryptDeriveKey(
                SafeProvHandle hProv,
                int algId,
                SafeHashHandle phHash,
                int dwFlags,
                out SafeKeyHandle phKey)
            {
                bool response = _CryptDeriveKey(hProv, algId, phHash, dwFlags, out phKey);

                phKey.SetParent(hProv);

                return response;
            }

 public static extern bool CryptHashData(SafeHashHandle hHash, byte[] pbData, int dwDataLen, int dwFlags);

 private static extern bool _CryptDeriveKey(SafeProvHandle safeProvHandle, int algId, SafeHashHandle phHash, int dwFlags, out SafeKeyHandle phKey);

 public static extern NTSTATUS BCryptFinishHash(SafeHashHandle hHash, [Out] byte[] pbOutput, int cbOutput, int dwFlags);

 public static extern unsafe NTSTATUS BCryptHashData(SafeHashHandle hHash, byte* pbInput, int cbInput, int dwFlags);

 public static extern NTSTATUS BCryptCreateHash(SafeAlgorithmHandle hAlgorithm, out SafeHashHandle phHash, IntPtr pbHashObject, int cbHashObject, [In, Out] byte[] pbSecret, int cbSecret, int dwFlags);

 public static extern NTSTATUS BCryptFinishHash(
     SafeHashHandle hHash,
     [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 2)] byte[] pbOutput,
     int cbOutput,
     BCryptFinishHashFlags dwFlags = BCryptFinishHashFlags.None);

 public static extern bool CryptEncrypt(SafeKeyHandle safeKeyHandle, SafeHashHandle safeHashHandle,
                                         bool Final, int dwFlags, byte[] pbData, ref int pdwDataLen,
                                         int dwBufLen);

 public static extern NTSTATUS BCryptCreateHash(
     SafeAlgorithmHandle hAlgorithm,
     out SafeHashHandle phHash,
     byte[] pbHashObject,
     int cbHashObject,
     byte[] pbSecret,
     int cbSecret,
     BCryptCreateHashFlags dwFlags);

 [System.Security.SecuritySafeCritical]  // auto-generated
 public override void Initialize() {
     if (_safeHashHandle != null && !_safeHashHandle.IsClosed)
         _safeHashHandle.Dispose();
     
     // _CreateHash will check for failures and throw the appropriate exception
     _safeHashHandle = Utils.CreateHash(Utils.StaticProvHandle, Constants.CALG_SHA1);
 }

 [System.Security.SecuritySafeCritical]  // auto-generated
 public SHA1CryptoServiceProvider() {
     // _CreateHash will check for failures and throw the appropriate exception
     _safeHashHandle = Utils.CreateHash(Utils.StaticProvHandle, Constants.CALG_SHA1);
 }