ruby IMAP STARTTLS means automatically disconnected? - ruby

Question

I am trying to write a simple IMAP client, that connects to an IMAP server, which enforces STARTTLS.
When i execute the command STARTTLS, the server connection is dropped. The documentation for STARTTLS on the other hand is a bit thin to know exactly, what the problem is.
The anonymized commands:
1.9.2-p320-railsexpress :001 > require 'net/imap'
=> nil
1.9.2-p320-railsexpress :002 > imap = Net::IMAP.new('SOME_HOST', 143, false)
=> #<Net::IMAP:0x0000000ba43138 #mon_owner=nil, #mon_count=0, #mon_mutex=#<Mutex:0x0000000ba430e8>, #host="SOME_HOST", #port=143, #tag_prefix="RUBY", #tagno=0, #parser=#<Net::IMAP::ResponseParser:0x0000000ba42be8 #str="* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE STARTTLS LOGINDISABLED] Dovecot ready.\r\n", #pos=110, #lex_state=:EXPR_BEG, #token=nil, #flag_symbols={}>, #sock=#<TCPSocket:fd 9>, #usessl=false, #responses={}, #tagged_responses={}, #response_handlers=[], #tagged_response_arrival=#<MonitorMixin::ConditionVariable:0x0000000ba42ad0 #monitor=#<Net::IMAP:0x0000000ba43138 ...>, #cond=#<ConditionVariable:0x0000000ba42aa8 #waiters=[], #waiters_mutex=#<Mutex:0x0000000ba42a58>>>, #continuation_request_arrival=#<MonitorMixin::ConditionVariable:0x0000000ba42a30 #monitor=#<Net::IMAP:0x0000000ba43138 ...>, #cond=#<ConditionVariable:0x0000000ba42a08 #waiters=[], #waiters_mutex=#<Mutex:0x0000000ba429b8>>>, #idle_done_cond=nil, #logout_command_tag=nil, #debug_output_bol=true, #exception=nil, #greeting=#<struct Net::IMAP::UntaggedResponse name="OK", data=#<struct Net::IMAP::ResponseText code=#<struct Net::IMAP::ResponseCode name="CAPABILITY", data="IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE STARTTLS LOGINDISABLED">, text=" Dovecot ready.">, raw_data="* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE STARTTLS LOGINDISABLED] Dovecot ready.\r\n">, #client_thread=#<Thread:0x007f416ed31420 run>, #receiver_thread=#<Thread:0x0000000ba41b58 run>>
1.9.2-p320-railsexpress :004 > imap.starttls
=> #<struct Net::IMAP::TaggedResponse tag="RUBY0001", name="OK", data=#<struct Net::IMAP::ResponseText code=nil, text="Begin TLS negotiation now.">, raw_data="RUBY0001 OK Begin TLS negotiation now.\r\n">
1.9.2-p320-railsexpress :006 > imap.disconnected?
=> true
I get the same behaviour in 2.0.0-p353-railsexpress.
Is this the correct behaviour and if so, how to correctly use ruby with an STARTTLS IMAP server?
thanks and regards!

Answer 1

Both client and server are working correctly up to the point where the client is supposed to start TLS negotiation. After that point the IMAP layer doesn't know what happens. You're going to enable TLS debug logging somewhere or sniff the network packets to make further progress.