CertExtensionValue Property

The raw value of this certificate extension.

Syntax

 certmgr.getCertExtensionValue(index, [callback])

Default Value

Callback

The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).

The callback for the getCertExtensionValue([callback]) method is defined as:

function(err, buffer){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'buffer' is the value returned by the method.

The callback for the setCertExtensionValue([callback]) method is defined as:

function(err){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'err' has 2 properties which hold detailed information:

err.code
err.message

Remarks

The raw value of this certificate extension. This value is encoded according to the extension's ASN.1 specification and should contain everything following the OID. Below is an example for clarity.

The example will

Add a sequence of basicConstraints indicating the holder of this certificate may not act as a CA.
Add a sequence of cRLDistributionPoints for where to get CRLs.

Certmgr mgr = new Certmgr();
mgr.Cert = new Certificate(CertStoreTypes.cstPFXFile, @"C:\signingcert.pfx", "password", "*");
mgr.CertExtensions.Clear();
mgr.Config("CertUsageFlags=0xA0"); //Key Encryption and Digital Signatures
mgr.Config("CertExtendedKeyUsage=1.3.6.1.5.5.7.3.1,1.3.6.1.5.5.7.3.2"); //Server and Client authentication (respectively)
mgr.Config("CertValidityTime=10000");

Netcode nc = new Netcode();
nc.Format = NetcodeFormats.fmtHex;

// Set basicConstraints to be an end-entity.
// Below is the hex-encoded value broken down.
// 30     // Tag = sequence
// 03     // Length
//   01   // Tag = boolean
//   01   // Length
//     00 // False (not a CA)

// Convert hex string to byte[]
nc.EncodedData = "3003010100";
nc.Decode();

string oid = "2.5.29.19"; // basicConstraints
byte[] value = nc.DecodedDataB;
bool critical = false;
CertExtension basicConstraints = new CertExtension(oid, value, critical);
mgr.CertExtensions.Add(basicConstraints);

// Add one point: http://www.nsoftware.com/dummy/MyCA.crl
// Below is the hex-encoded value broken down.
// 30                    // Tag = sequence
// 2F                    // Length
//   30                  // Tag = DistributionPoint
//   2D                  // Length
//     A0                // Tag = DistributionPointName
//     2B                // Length
//       A0              // Tag = GeneralNames
//       29              // Length
//         86            // Tag = GeneralName
//         27            // Length
//           687474703A2F2F7777772E6E736F6674776172652E636F6D2F64756D6D792F4D7943412E63726C // URL

// Convert hex string to byte[]
nc.EncodedData = "302F302DA02BA0298627687474703A2F2F7777772E6E736F6674776172652E636F6D2F64756D6D792F4D7943412E63726C";
nc.Decode();

oid = "2.5.29.31"; // cRLDistributionPoints
value = nc.DecodedDataB;
critical = false;
CertExtension crlDistributionPoints = new CertExtension(oid, value, critical);
mgr.CertExtensions.Add(crlDistributionPoints);

mgr.IssueCertificate("CN=www.petsbymatilda.com", 123);
Console.WriteLine(mgr.Cert.Encoded);

The index parameter specifies the index of the item in the array. The size of the array is controlled by the CertExtensionCount property.

This property is read-only and not available at design time.

Data Type