Move verify_arch to dcerpc_getarch

We can use this code elsewhere, such as the MS17-010 scanner.

lib/msf/core/exploit/dcerpc.rb

@@ -143,6 +143,70 @@ module Exploit::Remote::DCERPC
     end
   end
 
+  # XXX: Copypasta from exploit/windows/smb/ms17_010_eternalblue
+  #
+  # https://github.com/CoreSecurity/impacket/blob/master/examples/getArch.py
+  # https://msdn.microsoft.com/en-us/library/cc243948.aspx#Appendix_A_53
+  def dcerpc_getarch
+    ret = nil
+
+    connect_timeout = (datastore['ConnectTimeout'] || 10).to_i
+    read_timeout    = (datastore['DCERPC::ReadTimeout'] || 10).to_i
+
+    pkt = Rex::Proto::DCERPC::Packet.make_bind(
+      # Abstract Syntax: EPMv4 V3.0
+      'e1af8308-5d1f-11c9-91a4-08002b14a0fa', '3.0',
+      # Transfer Syntax[1]: 64bit NDR V1
+      '71710533-beba-4937-8319-b5dbef9ccc36', '1.0'
+    ).first
+
+    begin
+      nsock = Rex::Socket::Tcp.create(
+        'PeerHost'     => rhost,
+        'PeerPort'     => 135,
+        'Proxies'      => proxies,
+        'Timeout'      => connect_timeout,
+        'Context'      => {
+          'Msf'        => framework,
+          'MsfExploit' => self
+        }
+      )
+    rescue Rex::ConnectionError => e
+      vprint_error(e.to_s)
+      return nil
+    end
+
+    nsock.put(pkt)
+
+    begin
+      res = nsock.get_once(60, read_timeout)
+    rescue EOFError
+      vprint_error('DCE/RPC socket returned EOFError')
+      return nil
+    end
+
+    disconnect(nsock)
+
+    begin
+      resp = Rex::Proto::DCERPC::Response.new(res)
+    rescue Rex::Proto::DCERPC::Exceptions::InvalidPacket => e
+      vprint_error(e.to_s)
+      return nil
+    end
+
+    # Ack result: Acceptance (0)
+    if resp.ack_result.first == 0
+      ret = ARCH_X64
+    end
+    # Ack result: Provider rejection (2)
+    # Ack reason: Proposed transfer syntaxes not supported (2)
+    if resp.ack_result.first == 2 && resp.ack_reason.first == 2
+      ret = ARCH_X86
+    end
+
+    ret
+  end
+
   # Convert a standard ASCII string to 16-bit Unicode
   def unicode(str)
     Rex::Text.to_unicode(str)

modules/exploits/windows/smb/ms17_010_eternalblue.rb

@@ -10,7 +10,7 @@ require 'windows_error'
 class MetasploitModule < Msf::Exploit::Remote
   Rank = AverageRanking
 
-  include Msf::Exploit::Remote::Tcp
+  include Msf::Exploit::Remote::DCERPC
 
   def initialize(info = {})
     super(update_info(info,
@@ -267,63 +267,9 @@ class MetasploitModule < Msf::Exploit::Remote
     return ret
   end
 
-  # https://github.com/CoreSecurity/impacket/blob/master/examples/getArch.py
-  # https://msdn.microsoft.com/en-us/library/cc243948.aspx#Appendix_A_53
   def verify_arch
-    ret = false
-
-    return true if !datastore['VerifyArch']
-
-    pkt = Rex::Proto::DCERPC::Packet.make_bind(
-      # Abstract Syntax: EPMv4 V3.0
-      'e1af8308-5d1f-11c9-91a4-08002b14a0fa', '3.0',
-      # Transfer Syntax[1]: 64bit NDR V1
-      '71710533-beba-4937-8319-b5dbef9ccc36', '1.0'
-    ).first
-
-    begin
-      sock = connect(false,
-        'RHOST' => rhost,
-        'RPORT' => 135
-      )
-    rescue Rex::ConnectionError => e
-      print_error(e.to_s)
-      return false
-    end
-
-    sock.put(pkt)
-
-    begin
-      res = sock.get_once(60)
-    rescue EOFError
-      print_error('DCE/RPC socket returned EOFError')
-      return false
-    end
-
-    disconnect(sock)
-
-    begin
-      resp = Rex::Proto::DCERPC::Response.new(res)
-    rescue Rex::Proto::DCERPC::Exceptions::InvalidPacket => e
-      print_error(e.to_s)
-      return false
-    end
-
-    case target_arch.first
-    when ARCH_X64
-      # Ack result: Acceptance (0)
-      if resp.ack_result.first == 0
-        ret = true
-      end
-    when ARCH_X86
-      # Ack result: Provider rejection (2)
-      # Ack reason: Proposed transfer syntaxes not supported (2)
-      if resp.ack_result.first == 2 && resp.ack_reason.first == 2
-        ret = true
-      end
-    end
-
-    ret
+    return true unless datastore['VerifyArch']
+    (dcerpc_getarch == target_arch.first) ? true : false
   end
 
   def print_core_buffer(os)