public static extern uint NCryptVerifySignature(IntPtr hKey,
[In] ref BCRYPT_PSS_PADDING_INFO pPaddingInfo,
[In, MarshalAs(UnmanagedType.LPArray)] byte[] pbHashValue,
int cbHashValue,
[In, MarshalAs(UnmanagedType.LPArray)] byte[] pbSignature,
int cbSignature,
uint dwFlags);
public static extern uint NCryptSignHash(IntPtr hKey,
[In] ref BCRYPT_PSS_PADDING_INFO pPaddingInfo,
[In, MarshalAs(UnmanagedType.LPArray)] byte[] pbHashValue,
int cbHashValue,
IntPtr pbSignature,
int cbSignature,
[Out] out uint pcbResult,
uint dwFlags);
public static bool ValidateData(byte[] nonce, byte[] token, byte[] signature, byte[] certificate)
{
// Convert the Certificate Chain which is in a serialized format to SignedCms object.
SignedCms cms = new SignedCms();
cms.Decode(certificate);
// Looping through all certificates to find the leaf certificate.
X509Certificate2 leafCertificate = null;
foreach (X509Certificate2 x509 in cms.Certificates)
{
bool basicConstraintExtensionExists = false;
foreach (X509Extension extension in x509.Extensions)
{
if (extension.Oid.FriendlyName == "Basic Constraints")
{
basicConstraintExtensionExists = true;
X509BasicConstraintsExtension ext = (X509BasicConstraintsExtension)extension;
if (!ext.CertificateAuthority)
{
leafCertificate = x509;
break;
}
}
}
if (leafCertificate != null)
{
break;
}
if (!basicConstraintExtensionExists)
{
if (x509.Issuer != x509.Subject)
{
leafCertificate = x509;
break;
}
}
}
if (leafCertificate == null)
{
throw new ArgumentException("Leaf certificate could not be found");
}
// Validating the certificate chain. Ignore the errors due to online revocation check not
// being available. Also we are not failing validation due to expired certificates. Microsoft
// will be revoking the certificates that were exploided.
X509Chain chain = new X509Chain();
chain.ChainPolicy.RevocationFlag = X509RevocationFlag.EntireChain;
chain.ChainPolicy.RevocationMode = X509RevocationMode.Online;
chain.ChainPolicy.VerificationFlags = X509VerificationFlags.IgnoreNotTimeValid |
X509VerificationFlags.IgnoreCtlNotTimeValid |
X509VerificationFlags.IgnoreCertificateAuthorityRevocationUnknown |
X509VerificationFlags.IgnoreEndRevocationUnknown |
X509VerificationFlags.IgnoreCtlSignerRevocationUnknown;
chain.ChainPolicy.ApplicationPolicy.Add(new Oid("1.3.6.1.4.1.311.10.5.40"));
chain.ChainPolicy.RevocationMode = X509RevocationMode.NoCheck;
bool result = chain.Build(leafCertificate);
if (!result)
{
foreach (X509ChainStatus status in chain.ChainStatus)
{
switch (status.Status)
{
case X509ChainStatusFlags.NoError:
case X509ChainStatusFlags.NotTimeValid:
case X509ChainStatusFlags.NotTimeNested:
case X509ChainStatusFlags.CtlNotTimeValid:
case X509ChainStatusFlags.RevocationStatusUnknown:
case X509ChainStatusFlags.OfflineRevocation:
break;
#if DEBUG
case X509ChainStatusFlags.UntrustedRoot:
break;
#endif
default:
throw new ArgumentException("Chain verification failed with status " + status.Status);
}
}
}
// gRootPublicKey is the hard coded public key for the root certificate.
// Compare the public key on the root certificate with the hard coded one.
// They must match.
X509Certificate2 rootCertificate = chain.ChainElements[chain.ChainElements.Count - 1].Certificate;
if (!rootCertificate.PublicKey.EncodedKeyValue.RawData.SequenceEqual(gRootPublicKey))
{
throw new ArgumentException("Public key of the root certificate is not as expected.");
}
// Signature contains both nonce and hardwareId. So creating the combined data;
byte[] blob;
if (nonce == null)
{
blob = token;
}
else
{
blob = nonce.Concat(token).ToArray();
}
// Using the leaf Certificate we verify the signature of blob. The RSACryptoServiceProvider does not
// provide a way to pass in different padding mode. So we use Win32 NCryptVerifySignature API instead.
RSACryptoServiceProvider rsaCsp = leafCertificate.PublicKey.Key as RSACryptoServiceProvider;
RSAParameters parameters = rsaCsp.ExportParameters(false);
SHA1Managed sha1 = new SHA1Managed();
byte[] blobHash = sha1.ComputeHash(blob);
CngKey cngKey = CngKey.Import(GetPublicKey(parameters), CngKeyBlobFormat.GenericPublicBlob);
BCRYPT_PSS_PADDING_INFO paddingInfo = new BCRYPT_PSS_PADDING_INFO
{
pszAlgId = CngAlgorithm.Sha1.Algorithm,
cbSalt = 0
};
string[] lines = { "sha1: " + BitConverter.ToInt64(sha1.Hash, 0), " \n blobHash: " + BitConverter.ToInt64(blobHash, 0), "\n blob: " + BitConverter.ToInt64(blob, 0), "\n MachineId:" + BitConverter.ToInt64(token, 0) };
System.IO.File.WriteAllLines(@"C:\Users\YanBorowski\Desktop\Windows8.HardwareToken-master\W8\HardwareTokenSample\HardwareTokenValidationService\log.txt", lines);
int result2 = UnsafeNativeMethods.NCryptVerifySignature(
cngKey.Handle,
ref paddingInfo,
blobHash,
blobHash.Length,
signature,
signature.Length,
8); // NCRYPT_PAD_PSS_FLAG
if (result2 != 0) // 0 means ERROR_SUCCESS
{
return false; //throw new ArgumentException("Verification failed with " + result2);
}
return true;
}
