ICertificatePolicy Interface
Validates a server certificate.
Assembly: System (in System.dll)
| Name | Description | |
|---|---|---|
![]() | CheckValidationResult(ServicePoint, X509Certificate, WebRequest, Int32) | Validates a server certificate. |
The ICertificatePolicy interface is used to provide custom security certificate validation for an application. The default policy is to allow valid certificates, as well as valid certificates that have expired. To change this policy, implement the ICertificatePolicy interface with a different policy, and then assign that policy to ServicePointManager.CertificatePolicy.
ICertificatePolicy uses the Security Support Provider Interface (SSPI). For more information, see the SSPI documentation on MSDN.
The following example creates a certificate policy that returns false for any certificate problem and prints a message that indicates the problem on the console. The CertificateProblem enum defines SSPI constants for certificate problems, and the private GetProblemMessage method creates a printable message about the problem.
Public Enum CertificateProblem As Long CertEXPIRED = 2148204801 ' 0x800B0101 CertVALIDITYPERIODNESTING = 2148204802 ' 0x800B0102 CertROLE = 2148204803 ' 0x800B0103 CertPATHLENCONST = 2148204804 ' 0x800B0104 CertCRITICAL = 2148204805 ' 0x800B0105 CertPURPOSE = 2148204806 ' 0x800B0106 CertISSUERCHAINING = 2148204807 ' 0x800B0107 CertMALFORMED = 2148204808 ' 0x800B0108 CertUNTRUSTEDROOT = 2148204809 ' 0x800B0109 CertCHAINING = 2148204810 ' 0x800B010A CertREVOKED = 2148204812 ' 0x800B010C CertUNTRUSTEDTESTROOT = 2148204813 ' 0x800B010D CertREVOCATION_FAILURE = 2148204814 ' 0x800B010E CertCN_NO_MATCH = 2148204815 ' 0x800B010F CertWRONG_USAGE = 2148204816 ' 0x800B0110 CertUNTRUSTEDCA = 2148204818 ' 0x800B0112 End Enum Public Class MyCertificateValidation Implements ICertificatePolicy ' Default policy for certificate validation. Public Shared DefaultValidate As Boolean = False Public Function CheckValidationResult(srvPoint As ServicePoint, _ cert As X509Certificate, request As WebRequest, problem As Integer) _ As Boolean Implements ICertificatePolicy.CheckValidationResult Dim ValidationResult As Boolean = False Console.WriteLine(("Certificate Problem with accessing " & _ request.RequestUri.ToString())) Console.Write("Problem code 0x{0:X8},", CInt(problem)) Console.WriteLine(GetProblemMessage(CType(problem, _ CertificateProblem))) ValidationResult = DefaultValidate Return ValidationResult End Function Private Function GetProblemMessage(Problem As CertificateProblem) As String Dim ProblemMessage As String = "" Dim problemList As New CertificateProblem() Dim ProblemCodeName As String = System.Enum.GetName( _ problemList.GetType(), Problem) If Not (ProblemCodeName Is Nothing) Then ProblemMessage = ProblemMessage + "-Certificateproblem:" & _ ProblemCodeName Else ProblemMessage = "Unknown Certificate Problem" End If Return ProblemMessage End Function End Class
Available since 1.1
