November 2006 - stunnel-users

FD_SETSIZE and file ulimit
by Arunkumar Arumugam 10 Nov '06

10 Nov '06

Hi Guys - I have a stunnel setup in a linux box kernel 2.4 Advanced sever release 2.1AS (pensacola) . I am trying to increase the number of file descriptors with which stunnel could handle. So I did a ulimit -n 4096 for root and restarted the stunnel process. Now in the stunnel logs i see, ..... FD_SETSIZE=1024, file ulimit=4096- > 500 clients allowed. I dont completely understand the relation between FD_SETSIZE and file ulimit. I also read that a single stunnel connection might use around 2 or 3 file descriptors. So what is the cap on the number of file descriptors used by stunnel. To make it use , around 4096 file descriptors should i recompile the stunnel again with FD_SETSIZE set to 4096.? -- ARUN ARUMUGAM Galbraith's Law of Human Nature: Faced with the choice between changing ones' mind and proving that there is no need to do so, almost everybody gets busy on the proof.

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stunnel 4.16 wrapped around an ldap server causing very slow binds
by Mark McCoy 05 Nov '06

05 Nov '06

Hey all, I have an instance of stunnel 4.16 on Solaris 10 that I am trying to use to wrap Sun Directory Server LDAP traffic in SSL. LDAP 'binds' take over 2 minutes to complete using stunnel, but only a split second (as they should) when using an SSH tunnel. I have disabled tcpwrappers per the stunnel FAQ with no results, and tried settting delay = "yes" and "no", with no differences in the results. An interesting thing is that if I try to bind using the wrong password, the "Invalid Credentials" error returns immediately. Using the correct password, the bind hangs for over 2 minutes. Any ideas on what to look for? ------------- Output of stunnel -version: stunnel 4.16 on sparc-sun-solaris2.10 with OpenSSL 0.9.8c 05 Sep 2006 Threading:PTHREAD SSL:ENGINE Sockets:POLL,IPv4 Global options debug = 5 pid = /usr/local/stunnel/var/run/stunnel/stunnel.pid RNDbytes = 64 RNDfile = /dev/urandom RNDoverwrite = yes Service-level options cert = /usr/local/stunnel/etc/stunnel/stunnel.pem ciphers = ALL:!ADH:+RC4:@STRENGTH key = /usr/local/stunnel/etc/stunnel/stunnel.pem session = 300 seconds sslVersion = SSLv3 for client, all for server TIMEOUTbusy = 300 seconds TIMEOUTclose = 60 seconds TIMEOUTconnect = 10 seconds TIMEOUTidle = 43200 seconds verify = none -------------- -- Mark McCoy -- Professional Unix geek Here in America we are descended in blood and in spirit from revolutionists and rebels - men and women who dared to dissent from accepted doctrine. As their heirs, may we never confuse honest dissent with disloyal subversion. -- Dwight D. Eisenhower

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newbie sendmail + smtp question
by Fred nietzsche 03 Nov '06

03 Nov '06

My ISP requires all my mail to go to mail.myISP.net via SSL to port 465. I have sendmail compiled with STARTTLS, configured authinfo and I've set up sendmail's smarthost to send everything to mail.myISP.net I run stunnel like this. stunnel /etc/stunnel/stunnel.conf -c -d 25 -r mail.myISP.net:465 There are no errors in the log. I can see stunnel listening on 25 with netstat. When I try to send mail I get: bash-3.00# sendmail -v sc00b123(a)yahoo.com <test sc00b123(a)yahoo.com... Connecting to [127.0.0.1] via relay... Which just hangs for ever. My stunnel.conf looks like: cert = /etc/stunnel/mail.pem chroot = /var/stunnel/ setuid = nobody setgid = nogroup pid = /stunnel.pid socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 debug = 7 output = /var/log/stunnel.log [smtp] accept = 25 connect = 465 Thanks for any help, hints, etc.. --------------------------------- Low, Low, Low Rates! Check out Yahoo! Messenger's cheap PC-to-Phone call rates.

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stunnel[2840]: Error binding pop3s to 0.0.0.0:995
by fxper 02 Nov '06

02 Nov '06

I'm trying to use stunnel on a redhat machine to securely check email, via xinetd via pop3d. My /etc/xinetd.d/pop3s looks like this: service pop3s { socket_type = stream wait = no user = root server = /usr/sbin/stunnel log_on_success += USERID log_on_failure += USERID disable = no } And netstat just shows xinetd on 995: netstat -apn|grep 995 tcp 0 0 0.0.0.0:995 0.0.0.0:* LISTEN 2797/xinetd When I try to check mail with my client hitting port 995, I get this in /var/log/secure using debug level 7: Nov 1 16:17:24 myhostname xinetd[2797]: START: pop3s pid=2840 from=x.x.x.x Nov 1 16:17:54 myhostname stunnel[2840]: stunnel 4.04 on i386-redhat-linux-gnu PTHREAD+LIBWRAP with OpenSSL 0.9.7a Feb 19 2003 Nov 1 16:17:54 myhostname stunnel[2840]: Snagged 64 random bytes from /dev/urandom Nov 1 16:17:54 myhostname stunnel[2840]: RAND_status claims sufficient entropy for the PRNG Nov 1 16:17:54 myhostname stunnel[2840]: PRNG seeded successfully Nov 1 16:17:54 myhostname stunnel[2840]: Certificate: /usr/share/ssl/certs/stunnel.pem Nov 1 16:17:54 myhostname stunnel[2840]: Key file: /usr/share/ssl/certs/stunnel.pem Nov 1 16:17:54 myhostname stunnel[2840]: FD_SETSIZE=1024, file ulimit=1024 -> 500 clients allowed Nov 1 16:17:54 myhostname stunnel[2840]: FD 4 in non-blocking mode Nov 1 16:17:54 myhostname stunnel[2840]: SO_REUSEADDR option set on accept socket Nov 1 16:17:54 myhostname stunnel[2840]: Error binding pop3s to 0.0.0.0:995 Nov 1 16:17:54 myhostname stunnel[2840]: bind: Address already in use (98) Any suggestions? Thanks! --------------------------------- Want to start your own business? Learn how on Yahoo! Small Business.

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