question: public SubjectAlternativeNameExtension ( Boolean critical , Object value ) throws IOException { this . extensionId = PKIXExtensions . SubjectAlternativeName_Id ; this . critical = critical . booleanValue ( ) ; this . extensionValue = ( byte [ ] ) value ; DerValue val = new DerValue ( this . extensionValue ) ; if ( val . data == null ) { names = new GeneralNames ( ) ; return ; } names = new GeneralNames ( val ) ; }
target:  Create the extension from the passed DER encoded value.