Jak analizować alternatywne nazwy podmiotów z certyfikatu X509Certificate2?

Question

Czy można łatwo uzyskać alternatywne nazwy tematów z obiektu X509Certyfikat2?

 foreach (X509Extension ext in certificate.Extensions) 
     { 
      if (ext.Oid.Value.Equals(/* SAN OID */"2.5.29.17")) 
      { 
       byte[] raw = ext.RawData; 
       // ?????? parse to get type and name ???????? 
      } 
     } 

Answer 1

Użyj Format method rozszerzenia do wersji do druku.

X509Certificate2 cert = /* your code here */; 

foreach (X509Extension extension in cert.Extensions) 
{ 
    // Create an AsnEncodedData object using the extensions information. 
    AsnEncodedData asndata = new AsnEncodedData(extension.Oid, extension.RawData); 
    Console.WriteLine("Extension type: {0}", extension.Oid.FriendlyName); 
    Console.WriteLine("Oid value: {0}",asndata.Oid.Value); 
    Console.WriteLine("Raw data length: {0} {1}", asndata.RawData.Length, Environment.NewLine); 
    Console.WriteLine(asndata.Format(true)); 
} 

Answer 2

Aby uzyskać "Subject Alternative Name" z certyfikatem:

X509Certificate2 cert = /* your code here */; 

Console.WriteLine("UpnName : {0}{1}", cert.GetNameInfo(X509NameType.UpnName, false), Environment.NewLine); 

Answer 3

Stworzyłem funkcję, aby to zrobić:

private static List<string> ParseSujectAlternativeName(X509Certificate2 cert) 
{ 
      var result = new List<string>(); 

      var subjectAlternativeName = cert.Extensions.Cast<X509Extension>() 
               .Where(n => n.Oid.FriendlyName.EqualsCase(SubjectAlternativeName)) 
               .Select(n => new AsnEncodedData(n.Oid, n.RawData)) 
               .Select(n => n.Format(true)) 
               .FirstOrDefault(); 

      if (subjectAlternativeName != null) 
      { 
       var alternativeNames = subjectAlternativeName.Split(new[] { "\r\n", "\r", "\n" }, StringSplitOptions.None); 

       foreach (var alternativeName in alternativeNames) 
       { 
        var groups = Regex.Match(alternativeName, @"^DNS Name=(.*)").Groups; 

        if (groups.Count > 0 && !String.IsNullOrEmpty(groups[1].Value)) 
        { 
         result.Add(groups[1].Value); 
        } 
       } 
      } 

      return result;   
}