public static extern bool CryptSignAndEncodeCertificate
(
[param: In] NCryptKeyOrCryptProviderSafeHandle hCryptProvOrNCryptKey,
[param: In, MarshalAs(UnmanagedType.U4)] KeySpec dwKeySpec,
[param: In, MarshalAs(UnmanagedType.U4)] EncodingType dwCertEncodingType,
[param: In, MarshalAs(UnmanagedType.SysInt)] IntPtr lpszStructType,
[param: In, MarshalAs(UnmanagedType.Struct)] ref CERT_INFO pvStructInfo,
[param: In, MarshalAs(UnmanagedType.Struct)] ref CRYPT_ALGORITHM_IDENTIFIER pSignatureAlgorithm,
[param: In, MarshalAs(UnmanagedType.SysInt)] IntPtr pvHashAuxInfo,
[param: In, MarshalAs(UnmanagedType.SysInt)] IntPtr pbEncoded,
[param: In, Out, MarshalAs(UnmanagedType.U4)] ref uint pcbEncoded
);
public unsafe X509Certificate2 GenerateCertificate(X509Certificate2 issuingCertificate, PrivateKey privateKey, X500DistinguishedName dn, string[] dnsNames, DateTime? notBefore = null, DateTime? notAfter = null)
{
if (!issuingCertificate.HasPrivateKey)
{
throw new ArgumentException("Issuing certificate must have a private key.", nameof(issuingCertificate));
}
IntPtr basicEncodedDataPtr = IntPtr.Zero, certExtensionPtr = IntPtr.Zero;
var serialNumber = new byte[16];
var rng = RandomNumberGenerator.Create();
rng.GetNonZeroBytes(serialNumber);
fixed (byte* dnPtr = dn.RawData, issuerDnPtr = issuingCertificate.SubjectName.RawData, serialNumberPtr = serialNumber)
{
try
{
var blob = new NATIVE_CRYPTOAPI_BLOB
{
cbData = (uint)dn.RawData.Length,
pbData = dnPtr
};
var signatureAlgorithm = new CRYPT_ALGORITHM_IDENTIFIER
{
pszObjId = issuingCertificate.SignatureAlgorithm.Value
};
using (var signingKey = ExtractKey(issuingCertificate))
{
using (PublicKeyInfo publicKey = privateKey.ToPublicKey(), signingPublicKey = signingKey.ToPublicKey())
{
using (var extensions = new MarshalX509ExtensionCollection())
{
using (extensions.Freeze())
{
var usage = X509KeyUsageFlags.DigitalSignature;
if (privateKey.AlgorithmGroup == AlgorithmGroup.RSA)
{
//Key encipherment is not valid for DSA/ECDSA
usage |= X509KeyUsageFlags.KeyEncipherment;
}
extensions.Add(new X509BasicConstraintsExtension(false, false, 0, true));
extensions.Add(new X509KeyUsageExtension(usage, true));
extensions.Add(new X509EnhancedKeyUsageExtension(new OidCollection {new Oid(OIDs.EKU_SERVER)}, false));
extensions.Add(new X509SubjectAlternativeNameExtension(DnsAltNamesFromArray(dnsNames), false));
using (var sha1 = new SHA1CryptoServiceProvider())
{
var issuingKeyId = sha1.ComputeHash(signingPublicKey.Key);
extensions.Add(new X509SubjectKeyIdentifierExtension(sha1.ComputeHash(publicKey.Key), false));
extensions.Add(new X509AuthorityKeyIdentifierExtension(issuingKeyId, null));
}
}
var certInfo = new CERT_INFO();
certInfo.Subject = blob;
certInfo.SerialNumber = new NATIVE_CRYPTOAPI_BLOB {cbData = (uint) serialNumber.Length, pbData = serialNumberPtr};
certInfo.SubjectPublicKeyInfo = publicKey.PublicKey;
certInfo.dwVersion = CertificateVersion.CERT_V3;
certInfo.Issuer = new NATIVE_CRYPTOAPI_BLOB {cbData = (uint) issuingCertificate.SubjectName.RawData.Length, pbData = issuerDnPtr};
certInfo.SignatureAlgorithm = signatureAlgorithm;
certInfo.NotAfter = FileTimeHelper.ToFileTimeStructureUtc(notAfter ?? DateTime.Now.AddHours(-1).AddYears(5));
certInfo.NotBefore = FileTimeHelper.ToFileTimeStructureUtc(notBefore ?? DateTime.Now.AddHours(-1));
certInfo.cExtension = extensions.Extensions.cExtension;
certInfo.rgExtension = extensions.Extensions.rgExtension;
var size = 0u;
var CERT_INFO_TYPE = (IntPtr) 2;
if (!Crypt32.CryptSignAndEncodeCertificate(signingKey.Handle, KeySpec.NONE, EncodingType.X509_ASN_ENCODING, CERT_INFO_TYPE, ref certInfo, ref signatureAlgorithm, IntPtr.Zero, IntPtr.Zero, ref size))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
var buffer = Marshal.AllocHGlobal((int) size);
if (!Crypt32.CryptSignAndEncodeCertificate(signingKey.Handle, KeySpec.NONE, EncodingType.X509_ASN_ENCODING, CERT_INFO_TYPE, ref certInfo, ref signatureAlgorithm, IntPtr.Zero, buffer, ref size))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
const int CERT_KEY_PROV_INFO_PROP_ID = 2;
var certificate = new X509Certificate2(SerializeCertificate(buffer, size));
var keyProvInfo = new CRYPT_KEY_PROV_INFO
{
cProvParam = 0,
dwKeySpec = privateKey.Handle.IsNCryptKey ? KeySpec.NONE : KeySpec.AT_KEYEXCHANGE,
dwProvType = privateKey.Handle.IsNCryptKey ? ProviderType.CNG : ProviderType.PROV_RSA_AES,
pwszProvName = privateKey.ProviderName,
dwFlags = 0,
pwszContainerName = privateKey.Name
};
if (!Crypt32.CertSetCertificateContextProperty(certificate.Handle, CERT_KEY_PROV_INFO_PROP_ID, 0u, ref keyProvInfo))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
return new X509Certificate2(certificate);
}
}
}
}
finally
{
Marshal.FreeHGlobal(basicEncodedDataPtr);
Marshal.FreeHGlobal(certExtensionPtr);
}
}
}
