Add support for ldapwhoami (RFC4532)

.rubocop_todo.yml

@@ -221,7 +221,7 @@ Metrics/BlockNesting:
 # Offense count: 11
 # Configuration parameters: CountComments.
 Metrics/ClassLength:
-  Max: 445
+  Max: 451
 
 # Offense count: 23
 Metrics/CyclomaticComplexity:

lib/net/ldap.rb

@@ -341,6 +341,7 @@ class Net::LDAP
 
   StartTlsOid = '1.3.6.1.4.1.1466.20037'
   PasswdModifyOid = '1.3.6.1.4.1.4203.1.11.1'
+  WhoamiOid = '1.3.6.1.4.1.4203.1.11.3'
 
   # https://tools.ietf.org/html/rfc4511#section-4.1.9
   # https://tools.ietf.org/html/rfc4511#appendix-A
@@ -1198,6 +1199,23 @@ def delete_tree(args)
     end
   end
 
+  # Return the authorization identity of the client that issues the
+  # ldapwhoami request.  The method does not support any arguments.
+  #
+  # Returns True or False to indicate whether the request was successfull.
+  # The result is available in the extended status information when calling
+  # #get_operation_result.
+  #
+  #  ldap.ldapwhoami
+  #  puts ldap.get_operation_result.extended_response
+  def ldapwhoami(args = {})
+    instrument "ldapwhoami.net_ldap", args do |payload|
+      @result = use_connection(args, &:ldapwhoami)
+      @result.success?
+    end
+  end
+  alias_method :whoami, :ldapwhoami
+
   # This method is experimental and subject to change. Return the rootDSE
   # record from the LDAP server as a Net::LDAP::Entry, or an empty Entry if
   # the server doesn't return the record.

lib/net/ldap/connection.rb

@@ -685,6 +685,24 @@ def delete(args)
     pdu
   end
 
+  def ldapwhoami
+    Net::LDAP::AsnSyntax[139] = :string
+    ext_seq = [Net::LDAP::WhoamiOid.to_ber_contextspecific(0)]
+    request = ext_seq.to_ber_appsequence(Net::LDAP::PDU::ExtendedRequest)
+
+    message_id = next_msgid
+
+    write(request, nil, message_id)
+    pdu = queued_read(message_id)
+
+    if !pdu || pdu.app_tag != Net::LDAP::PDU::ExtendedResponse
+      raise Net::LDAP::ResponseMissingOrInvalidError, "response missing or invalid"
+    end
+
+    Net::LDAP::AsnSyntax[139] = nil
+    pdu
+  end
+
   # Internal: Returns a Socket like object used internally to communicate with
   # LDAP server.
   #