VB.NET

Find Certificate by Email Address

See more Cert Store Examples

Demonstrates how to find a certificate having the specified email address either within the cert's subject email, or the RFC822 name.

In an X.509 certificate, an email address can typically be located in two places:

1. RFC822 Name (Subject Alternative Name extension) -
   • The certificate may include an email address in the Subject Alternative Name (SAN) extension under the RFC822 Name field. This is a modern and preferred method because it allows for flexibility and alignment with security best practices.
   • To find it, Chilkat inspects the SAN extension in the certificate details.
2. Subject (Common Name or Email Address attribute) -
   • Older certificates may store the email address directly in the Subject field, typically under the Email Address attribute ("emailAddress") or, less commonly, the Common Name (CN).
   • This method is less preferred in modern standards but can still be encountered in legacy implementations. Chilkat also searches here for the email address.

Note: Requires Chilkat v10.1.2 or later.

VB.NET

Dim success As Boolean = False

Dim certStore As New Chilkat.CertStore

' This opens the Current User certificate store on Windows,
' On MacOS and iOS it opens the default Keychain.
Dim readOnly As Boolean = False
success = certStore.OpenCurrentUserStore(readOnly)
If (success = False) Then
    Debug.WriteLine(certStore.LastErrorText)
    Exit Sub
End If


' Find the certificate having the specified email address in either the RFC822 Name or in the Subject.
Dim json As New Chilkat.JsonObject
Dim email_address As String = "joe@example.com"
json.UpdateString("email",email_address)

Dim cert As New Chilkat.Cert
success = certStore.FindCert(json,cert)
If (success = True) Then
    ' Show the full distinguished name of the certificate.
    Debug.WriteLine("Found: " & cert.SubjectDN)
Else
    Debug.WriteLine("Not found.")
End If