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X509VerificationFlags Enum


Specifies conditions under which verification of certificates in the X509 chain should be conducted.

This enumeration supports a bitwise combination of its member values.

public enum class X509VerificationFlags
public enum X509VerificationFlags
type X509VerificationFlags = 
Public Enum X509VerificationFlags


AllFlags 4095

All flags pertaining to verification are included.

AllowUnknownCertificateAuthority 16

Ignore that the chain cannot be verified due to an unknown certificate authority (CA) or partial chains.

IgnoreCertificateAuthorityRevocationUnknown 1024

Ignore that the certificate authority revocation is unknown when determining certificate verification.

IgnoreCtlNotTimeValid 2

Ignore that the certificate trust list (CTL) is not valid, for reasons such as the CTL has expired, when determining certificate verification.

IgnoreCtlSignerRevocationUnknown 512

Ignore that the certificate trust list (CTL) signer revocation is unknown when determining certificate verification.

IgnoreEndRevocationUnknown 256

Ignore that the end certificate (the user certificate) revocation is unknown when determining certificate verification.

IgnoreInvalidBasicConstraints 8

Ignore that the basic constraints are not valid when determining certificate verification.

IgnoreInvalidName 64

Ignore that the certificate has an invalid name when determining certificate verification.

IgnoreInvalidPolicy 128

Ignore that the certificate has invalid policy when determining certificate verification.

IgnoreNotTimeNested 4

Ignore that the CA (certificate authority) certificate and the issued certificate have validity periods that are not nested when verifying the certificate. For example, the CA cert can be valid from January 1 to December 1 and the issued certificate from January 2 to December 2, which would mean the validity periods are not nested.

IgnoreNotTimeValid 1

Ignore certificates in the chain that are not valid either because they have expired or they are not yet in effect when determining certificate validity.

IgnoreRootRevocationUnknown 2048

Ignore that the root revocation is unknown when determining certificate verification.

IgnoreWrongUsage 32

Ignore that the certificate was not issued for the current use when determining certificate verification.

NoFlag 0

No flags pertaining to verification are included.


The following example opens the current user's personal certificate store, allows the user to select a certificate, then writes certificate and certificate chain information to the console. The output depends on the certificate you select.

//Output chain information of the selected certificate.
X509Chain ^ ch = gcnew X509Chain;
ch->ChainPolicy->RevocationMode = X509RevocationMode::Online;
ch->Build( certificate );
Console::WriteLine( "Chain Information" );
Console::WriteLine( "Chain revocation flag: {0}", ch->ChainPolicy->RevocationFlag );
Console::WriteLine( "Chain revocation mode: {0}", ch->ChainPolicy->RevocationMode );
Console::WriteLine( "Chain verification flag: {0}", ch->ChainPolicy->VerificationFlags );
Console::WriteLine( "Chain verification time: {0}", ch->ChainPolicy->VerificationTime );
Console::WriteLine( "Chain status length: {0}", ch->ChainStatus->Length );
Console::WriteLine( "Chain application policy count: {0}", ch->ChainPolicy->ApplicationPolicy->Count );
Console::WriteLine( "Chain certificate policy count: {0} {1}", ch->ChainPolicy->CertificatePolicy->Count, Environment::NewLine );
//Output chain information of the selected certificate.
X509Chain ch = new X509Chain();
ch.ChainPolicy.RevocationMode = X509RevocationMode.Online;
ch.Build (certificate);
Console.WriteLine ("Chain Information");
Console.WriteLine ("Chain revocation flag: {0}", ch.ChainPolicy.RevocationFlag);
Console.WriteLine ("Chain revocation mode: {0}", ch.ChainPolicy.RevocationMode);
Console.WriteLine ("Chain verification flag: {0}", ch.ChainPolicy.VerificationFlags);
Console.WriteLine ("Chain verification time: {0}", ch.ChainPolicy.VerificationTime);
Console.WriteLine ("Chain status length: {0}", ch.ChainStatus.Length);
Console.WriteLine ("Chain application policy count: {0}", ch.ChainPolicy.ApplicationPolicy.Count);
Console.WriteLine ("Chain certificate policy count: {0} {1}", ch.ChainPolicy.CertificatePolicy.Count, Environment.NewLine);
'Output chain information of the selected certificate.
Dim ch As New X509Chain()
ch.ChainPolicy.RevocationMode = X509RevocationMode.Online
Console.WriteLine("Chain Information")
Console.WriteLine("Chain revocation flag: {0}", ch.ChainPolicy.RevocationFlag)
Console.WriteLine("Chain revocation mode: {0}", ch.ChainPolicy.RevocationMode)
Console.WriteLine("Chain verification flag: {0}", ch.ChainPolicy.VerificationFlags)
Console.WriteLine("Chain verification time: {0}", ch.ChainPolicy.VerificationTime)
Console.WriteLine("Chain status length: {0}", ch.ChainStatus.Length)
Console.WriteLine("Chain application policy count: {0}", ch.ChainPolicy.ApplicationPolicy.Count)
Console.WriteLine("Chain certificate policy count: {0} {1}", ch.ChainPolicy.CertificatePolicy.Count, Environment.NewLine)


These flags indicate the conditions under which chain verification should occur. For example, if an application does not require certificates time values in a chain to be valid, the IgnoreNotTimeValid flag can be used.

Applies to