/// <summary>
        /// Encode and sign a CERT_INFO structure
        /// </summary>
        /// <param name="hProv"></param>
        /// <param name="certInfo"></param>
        /// <param name="signature">True encodes with a AT_SIGNATURE key, otherwise AT_EXCHANGE</param>
        /// <param name="hashAlgorithm"></param>
        /// <returns></returns>
        private byte[] EncodeAndSignCertInfo(CryptoApiMethods.SafeCryptProviderHandle hProv, CryptoApiMethods.CERT_INFO certInfo, bool signature, CertificateHashAlgorithm hashAlgorithm)
        {
            CryptoApiMethods.CALG keyType = signature ? CryptoApiMethods.CALG.AT_SIGNATURE : CryptoApiMethods.CALG.AT_KEYEXCHANGE;
            byte[] ret         = null;
            uint   certLen     = 0;
            IntPtr certInfoPtr = IntPtr.Zero;

            CryptoApiMethods.CRYPT_ALGORITHM_IDENTIFIER SignatureAlgorithm = new CryptoApiMethods.CRYPT_ALGORITHM_IDENTIFIER();
            //SignatureAlgorithm.pszObjId = CryptoApiMethods.szOID_OIWSEC_sha1RSASign;
            //SignatureAlgorithm.pszObjId = CryptoApiMethods.szOID_RSA_SHA1RSA;
            //SignatureAlgorithm.pszObjId = CryptoApiMethods.szOID_RSA_SHA512RSA;
            SignatureAlgorithm.pszObjId = HashAlgorithmToOID(hashAlgorithm);

            try
            {
                certInfoPtr = Marshal.AllocHGlobal(Marshal.SizeOf(certInfo));
                Marshal.StructureToPtr(certInfo, certInfoPtr, false);

                if (!CryptoApiMethods.CryptSignAndEncodeCertificate(hProv, keyType, CryptoApiMethods.CertEncoding.X509_ASN_ENCODING,
                                                                    new IntPtr((int)CryptoApiMethods.StructType.X509_CERT_TO_BE_SIGNED), certInfoPtr, SignatureAlgorithm, IntPtr.Zero, null, ref certLen))
                {
                    throw new Win32Exception(Marshal.GetLastWin32Error());
                }

                ret = new byte[certLen];

                if (!CryptoApiMethods.CryptSignAndEncodeCertificate(hProv, keyType, CryptoApiMethods.CertEncoding.X509_ASN_ENCODING,
                                                                    new IntPtr((int)CryptoApiMethods.StructType.X509_CERT_TO_BE_SIGNED), certInfoPtr, SignatureAlgorithm, IntPtr.Zero, ret, ref certLen))
                {
                    throw new Win32Exception(Marshal.GetLastWin32Error());
                }
            }
            finally
            {
                Marshal.DestroyStructure(certInfoPtr, certInfo.GetType());
                Marshal.FreeHGlobal(certInfoPtr);
            }

            return(ret);
        }
        /// <summary>
        /// Encode and sign a CERT_INFO structure
        /// </summary>
        /// <param name="hProv"></param>
        /// <param name="certInfo"></param>
        /// <param name="signature">True encodes with a AT_SIGNATURE key, otherwise AT_EXCHANGE</param>
        /// <param name="hashAlgorithm"></param>
        /// <returns></returns>
        private byte[] EncodeAndSignCertInfo(CryptoApiMethods.SafeCryptProviderHandle hProv, CryptoApiMethods.CERT_INFO certInfo, bool signature, CertificateHashAlgorithm hashAlgorithm)
        {
            CryptoApiMethods.CALG keyType = signature ? CryptoApiMethods.CALG.AT_SIGNATURE : CryptoApiMethods.CALG.AT_KEYEXCHANGE;
            byte[] ret = null;
            uint certLen = 0;
            IntPtr certInfoPtr = IntPtr.Zero;
            CryptoApiMethods.CRYPT_ALGORITHM_IDENTIFIER SignatureAlgorithm = new CryptoApiMethods.CRYPT_ALGORITHM_IDENTIFIER();
            //SignatureAlgorithm.pszObjId = CryptoApiMethods.szOID_OIWSEC_sha1RSASign;
            //SignatureAlgorithm.pszObjId = CryptoApiMethods.szOID_RSA_SHA1RSA;
            //SignatureAlgorithm.pszObjId = CryptoApiMethods.szOID_RSA_SHA512RSA;
            SignatureAlgorithm.pszObjId = HashAlgorithmToOID(hashAlgorithm);

            try
            {
                certInfoPtr = Marshal.AllocHGlobal(Marshal.SizeOf(certInfo));
                Marshal.StructureToPtr(certInfo, certInfoPtr, false);

                if (!CryptoApiMethods.CryptSignAndEncodeCertificate(hProv, keyType, CryptoApiMethods.CertEncoding.X509_ASN_ENCODING,
                    new IntPtr((int)CryptoApiMethods.StructType.X509_CERT_TO_BE_SIGNED), certInfoPtr, SignatureAlgorithm, IntPtr.Zero, null, ref certLen))
                {
                    throw new Win32Exception(Marshal.GetLastWin32Error());
                }

                ret = new byte[certLen];

                if (!CryptoApiMethods.CryptSignAndEncodeCertificate(hProv, keyType, CryptoApiMethods.CertEncoding.X509_ASN_ENCODING,
                    new IntPtr((int)CryptoApiMethods.StructType.X509_CERT_TO_BE_SIGNED), certInfoPtr, SignatureAlgorithm, IntPtr.Zero, ret, ref certLen))
                {
                    throw new Win32Exception(Marshal.GetLastWin32Error());
                }
            }
            finally
            {
                Marshal.DestroyStructure(certInfoPtr, certInfo.GetType());
                Marshal.FreeHGlobal(certInfoPtr);
            }

            return ret;
        }