- stunnel-users - stunnel.org

Stunnel activity issue
by Денис Голубятников 26 Jan '23

26 Jan '23

I have problems with stunnel on OS Windows. After a successful connection with stunnel, the connection drops after approximately 9 minutes of inactivity. On Linux, this problem was solved by changing this parametrs: net.ipv4.tcp_keepalive_time = 60 net.ipv4.tcp_keepalive_intvl = 30 net.ipv4.tcp_keepalive_probes = 20 I don't have access to the server side router, so I can't change anything. Stunnel log: 2023.01.25 17:18:10 LOG7[1]: Service [test] started 2023.01.25 17:18:10 LOG7[1]: Setting local socket options (FD=964) 2023.01.25 17:18:10 LOG7[1]: Option TCP_NODELAY set on local socket 2023.01.25 17:18:10 LOG5[1]: Service [test] accepted connection from 127.0.0.1:50145 2023.01.25 17:18:10 LOG6[1]: s_connect: connecting 225.179.85.93:18572 2023.01.25 17:18:10 LOG7[1]: s_connect: s_poll_wait 225.179.85.93:18572: waiting 10 seconds 2023.01.25 17:18:10 LOG7[1]: FD=716 ifds=rwx ofds=--- 2023.01.25 17:18:10 LOG5[1]: s_connect: connected 225.179.85.93:18572 2023.01.25 17:18:10 LOG5[1]: Service [onegomed] connected remote server from 192.168.1.84:50146 2023.01.25 17:18:10 LOG7[1]: Setting remote socket options (FD=716) 2023.01.25 17:18:10 LOG7[1]: Option TCP_NODELAY set on remote socket 2023.01.25 17:18:10 LOG7[1]: Remote descriptor (FD=716) initialized 2023.01.25 17:18:10 LOG6[1]: SNI: sending servername: 225.179.85.93 2023.01.25 17:18:10 LOG6[1]: Peer certificate not required 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): before SSL initialization 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS write client hello 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS write client hello 2023.01.25 17:18:10 LOG7[1]: Initializing application specific data for session authenticated 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS read server hello 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): TLSv1.3 read encrypted extensions 2023.01.25 17:18:10 LOG6[1]: Certificate verification disabled 2023.01.25 17:18:10 LOG6[1]: Certificate verification disabled 2023.01.25 17:18:10 LOG6[1]: Certificate verification disabled 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS read server certificate 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): TLSv1.3 read server certificate verify 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS read finished 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS write change cipher spec 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS write finished 2023.01.25 17:18:10 LOG7[1]: 2 client connect(s) requested 2023.01.25 17:18:10 LOG7[1]: 2 client connect(s) succeeded 2023.01.25 17:18:10 LOG7[1]: 0 client renegotiation(s) requested 2023.01.25 17:18:10 LOG7[1]: 0 session reuse(s) 2023.01.25 17:18:10 LOG6[1]: TLS connected: new session negotiated 2023.01.25 17:18:10 LOG6[1]: TLSv1.3 ciphersuite: TLS_AES_256_GCM_SHA384 (256-bit encryption) 2023.01.25 17:18:10 LOG6[1]: Peer temporary key: X25519, 253 bits 2023.01.25 17:18:10 LOG7[1]: Compression: null, expansion: null 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSL negotiation finished successfully 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSL negotiation finished successfully 2023.01.25 17:18:10 LOG7[1]: Initializing application specific data for session authenticated 2023.01.25 17:18:10 LOG7[1]: Deallocating application specific data for session connect address 2023.01.25 17:18:10 LOG7[1]: New session callback 2023.01.25 17:18:10 LOG7[1]: Deallocating application specific data for session connect address 2023.01.25 17:18:10 LOG6[1]: Session id: 8E91DBE369D9E16221CCA288A7C1F652AB045BAE96C19B4240B1B7F710069CCE 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS read server session ticket 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSL negotiation finished successfully 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSL negotiation finished successfully 2023.01.25 17:18:10 LOG7[1]: Initializing application specific data for session authenticated 2023.01.25 17:18:10 LOG7[1]: New session callback 2023.01.25 17:18:10 LOG7[1]: Deallocating application specific data for session connect address 2023.01.25 17:18:10 LOG6[1]: Session id: 6UIA254BF9D027B3D4BE5F966BDE9DE2058CF167C4EF0CD5A460958B698DF322 2023.01.25 17:18:10 LOG7[1]: TLS state (connect): SSLv3/TLS read server session ticket 2023.01.25 17:33:25 LOG3[1]: SSL_read: Connection reset by peer (WSAECONNRESET) (10054) 2023.01.25 17:33:25 LOG5[1]: Connection reset: 5184 byte(s) sent to TLS, 10344 byte(s) sent to socket 2023.01.25 17:33:25 LOG7[1]: Remote descriptor (FD=716) closed 2023.01.25 17:33:25 LOG7[1]: Local descriptor (FD=964) closed 2023.01.25 17:33:25 LOG7[1]: Service [test] finished (0 left)` I tried: * changing the windows registry: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\KeepAliveTime HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\KeepAliveInterval HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpMaxDataRetransmissions HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TdxPrematureConnectIndDisabled HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\InternetSetting\KeepAliveTimeout HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\InternetSetting\ServerInfoTimeout * changing stunnel config on client side: socket = l:SO_KEEPALIVE=1 socket = r:SO_KEEPALIVE=1 * changing parametrs on linux server side: net.ipv4.tcp_keepalive_time = 60 net.ipv4.tcp_keepalive_intvl = 30 net.ipv4.tcp_keepalive_probes = 20 * add server cert on stunnel client config; * downgrade and update stunnel. -- Gordon Stevenson Отправлено из Почты Mail.ru

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forward all UDP port
by Ahmad Kiamanesh 23 Jan '23

23 Jan '23

Hi how can forward all inner UDP ports from one server to another server?

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STunnel not passing traffic
by Gary Jackson 15 Jan '23

15 Jan '23

I have an application that sends XML encrypted traffic over TCP to Stunnel. Stunnel is supposed to unencrypt and send to backend application unencrypted, however no traffic is sent. I have used wireshark and I do see the client hello for tls1.2 and the server hello for tls 1.2 so the cipher negotiation is completed. Here is my config: sslVersionMax = TLSv1.2 options = -NO_SSLv3 [https] accept = 27015 connect = 27001 cert = cert.pem key = key.pem TIMEOUTclose = 0 STunnel Log in Debug 7 2023.01.13 14:03:42 LOG7[16572]: Service [https] started 2023.01.13 14:03:42 LOG7[16572]: Setting local socket options (FD=1888) 2023.01.13 14:03:42 LOG7[16572]: Option TCP_NODELAY set on local socket 2023.01.13 14:03:42 LOG5[16572]: Service [https] accepted connection from xx.xx.xx.xx:62478 2023.01.13 14:03:42 LOG6[16572]: Peer certificate not required 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): before SSL initialization 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): before SSL initialization 2023.01.13 14:03:42 LOG7[16572]: Decrypt session ticket callback 2023.01.13 14:03:42 LOG7[16572]: Initializing application specific data for session authenticated 2023.01.13 14:03:42 LOG7[16572]: SNI: no virtual services defined 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS read client hello 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS write server hello 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS write certificate 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS write key exchange 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS write server done 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS write server done 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS read client key exchange 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS read change cipher spec 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS read finished 2023.01.13 14:03:42 LOG7[16572]: Generate session ticket callback 2023.01.13 14:03:42 LOG7[16572]: Initializing application specific data for session authenticated 2023.01.13 14:03:42 LOG7[16572]: Deallocating application specific data for session connect address 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS write session ticket 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS write change cipher spec 2023.01.13 14:03:42 LOG7[16572]: TLS state (accept): SSLv3/TLS write finished 2023.01.13 14:03:42 LOG7[16572]: 33 server accept(s) requested 2023.01.13 14:03:42 LOG7[16572]: 33 server accept(s) succeeded 2023.01.13 14:03:42 LOG7[16572]: 0 server renegotiation(s) requested 2023.01.13 14:03:42 LOG7[16572]: 0 session reuse(s) 2023.01.13 14:03:42 LOG7[16572]: 1 internal session cache item(s) 2023.01.13 14:03:42 LOG7[16572]: 0 internal session cache fill-up(s) 2023.01.13 14:03:42 LOG7[16572]: 0 internal session cache miss(es) 2023.01.13 14:03:42 LOG7[16572]: 0 external session cache hit(s) 2023.01.13 14:03:42 LOG7[16572]: 0 expired session(s) retrieved 2023.01.13 14:03:42 LOG6[16572]: TLS accepted: new session negotiated 2023.01.13 14:03:42 LOG6[16572]: TLSv1.2 ciphersuite: ECDHE-RSA-AES256-GCM-SHA384 (256-bit encryption) 2023.01.13 14:03:42 LOG3[16572]: SSL_get_peer_tmp_key: Peer suddenly disconnected 2023.01.13 14:03:42 LOG7[16572]: Compression: null, expansion: null 2023.01.13 14:03:42 LOG7[16572]: Deallocating application specific data for session connect address 2023.01.13 14:03:42 LOG6[16572]: s_connect: connecting 127.0.0.1:27001 2023.01.13 14:03:42 LOG7[16572]: s_connect: s_poll_wait 127.0.0.1:27001: waiting 10 seconds 2023.01.13 14:03:42 LOG7[16572]: FD=1472 ifds=rwx ofds=--- 2023.01.13 14:03:42 LOG5[16572]: s_connect: connected 127.0.0.1:27001 2023.01.13 14:03:42 LOG6[16572]: persistence: 127.0.0.1:27001 cached 2023.01.13 14:03:42 LOG5[16572]: Service [https] connected remote server from 127.0.0.1:56732 2023.01.13 14:03:42 LOG7[16572]: Setting remote socket options (FD=1472) 2023.01.13 14:03:42 LOG7[16572]: Option TCP_NODELAY set on remote socket 2023.01.13 14:03:42 LOG7[16572]: Remote descriptor (FD=1472) initialized 2023.01.13 14:03:42 LOG6[16572]: SSL_read: Socket is closed 2023.01.13 14:03:42 LOG6[16572]: TLS socket closed (SSL_read) 2023.01.13 14:03:42 LOG7[16572]: Sent socket write shutdown 2023.01.13 14:03:42 LOG5[16572]: Connection closed: 0 byte(s) sent to TLS, 0 byte(s) sent to socket 2023.01.13 14:03:42 LOG7[16572]: Remote descriptor (FD=1472) closed 2023.01.13 14:03:42 LOG7[16572]: Local descriptor (FD=1888) closed 2023.01.13 14:03:42 LOG7[16572]: Service [https] finished (1 left) Any assistance you can provide would be glorious! _________________________________ Gary Jackson

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Setup and Installing stunnel on windows wsl2 Ubuntu
by adamsaltlake＠hotmail.com 25 Nov '22

25 Nov '22

I am new to stunnel and have been struggling for weeks to get it to work on windows wsl2 ubuntu; it keep failing with pid error "You should check that you have specified the pid= in you configuration file" any idea is welcome

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Self signed certificate check
by Bob Bob 20 Nov '22

20 Nov '22

Hi, I have two Windows based stations with one hosting a specific service. Stunnel is used to create a secure connection. As stated on the auth page, I have implemented PSK to prevent MITM Attack but also as a way to authenticate connections and limit who can connect to the server. I would like to add an extra layer of security by having the Server only accept connections when the client submits a pre-agreed self cert. verifyPeer does not seem to work with self certificate. I would like to end up with PSK + certificate check. Is there a way to achieve that with self certificate on Stunnel? Thanks.

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Windows 10 Pro - StartService: error 1053
by jason99si＠gmail.com 11 Nov '22

11 Nov '22

I'm installing stunnel for a second time. I'm using it for Blue Iris on a Windows 10 Pro machine. I'm using stunnel 5.67 on Win64. GUI shows "Configuration successful". I've tried uninstalling and reinstalling numerous times. When I run stunnel Service Start I receive a dialog box that says: stunnel 5.67 on Win64 (not configured) StartService: error 1053: The service did not respond to the start or control request in a timely fashion Can anyone help?

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Two certificates on same connection
by perisnagini＠gmail.com 07 Nov '22

07 Nov '22

hi, I am into implementations and generally use stunnel with a certification provided by our third party connections in stunnel for encryption/ decryption both ways. Recently we had a query from one of our vendors stating we must use one cert to encrypt which they will decrypt using the key provided by us and they will encrypt which must be decrypted using the key provided. Keeping it simple we have below: Client Key - clt.pem Client cert - clt.cer Vendor key - vndr.pem our ca certs - ca-cert.pem Could anyone help me in understanding how do I leverage vendor key for decrypting and clt key for encrypting in stunnel.conf using the above certs. Many Thanks.

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error:0A000126:SSL routines::unexpected eof while reading
by sburke＠unitedelectric.com 07 Nov '22

07 Nov '22

Hello, I am trying to get a system notification email back up and running after google disabled the "use less secure apps" functionality in the Gmail platform. I have set up the Gmail account to use an app password which I assigned to the system that was sending emails before this change. It appears the system is now connecting to Stunnel running on a windows 10 machine and Stunnel is making the connection with the Gmail server again, but no email actually gets sent out. I am running Stunnel 5.66 Here is the configuration currently: [gmail-smtp] client = yes accept = 25 connect = smtp.gmail.com:465 verifyChain = yes CAfile = ca-certs.pem checkHost = smtp.Gmail.com OCSPaia = yes Here is a copy of the log file: 2022.09.20 07:40:49 LOG5[0]: Service [gmail-smtp] accepted connection from 192.168.100.200:56399 2022.09.20 07:40:49 LOG5[0]: s_connect: connected 74.125.138.109:465 2022.09.20 07:40:49 LOG5[0]: Service [gmail-smtp] connected remote server from 172.16.4.220:60367 2022.09.20 07:40:49 LOG5[0]: OCSP: Connecting the AIA responder "http://ocsp.pki.goog/gtsr1" 2022.09.20 07:40:50 LOG5[0]: s_connect: connected 142.251.40.67:80 2022.09.20 07:40:50 LOG5[0]: OCSP: Certificate accepted 2022.09.20 07:40:50 LOG5[0]: OCSP: Connecting the AIA responder "http://ocsp.pki.goog/gts1c3" 2022.09.20 07:40:50 LOG5[0]: s_connect: connected 142.251.40.67:80 2022.09.20 07:40:50 LOG5[0]: OCSP: Certificate accepted 2022.09.20 07:40:50 LOG5[0]: Certificate accepted at depth=0: CN=smtp.gmail.com 2022.09.20 07:40:51 LOG3[0]: SSL_read: ssl/record/rec_layer_s3.c:308: error:0A000126:SSL routines::unexpected eof while reading 2022.09.20 07:40:51 LOG5[0]: Connection reset: 92 byte(s) sent to TLS, 620 byte(s) sent to socket Is this something I can remedy from the configuration, or is this something that requires modification on the email server side? Thank you sean

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Re: stunnel 5.67 released
by Rok Berlec 07 Nov '22

07 Nov '22

Hi, When we install version 5.67 we sometimes get the message: "The procedure entry point OPENSSL_strcasecmp could not be located" After start of service everything looks fine. We upgrade by uninstalling the previous version and installing the latest one. Best regards, Rok Berlec

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stunnel 5.67 released
by Michał Trojnara 01 Nov '22

01 Nov '22

Dear Users, I have released version 5.67 of stunnel. ### Version 5.67, 2022.11.01, urgency: HIGH * Security bugfixes - OpenSSL DLLs updated to version 3.0.7. * New features - Provided a logging callback to custom engines. * Bugfixes - Fixed "make cert" with OpenSSL older than 3.0. - Fixed the code and the documentation to use conscious language for SNI servers (thx to Clemens Lang). Home page: https://www.stunnel.org/ Download: https://www.stunnel.org/downloads.html SHA-256 hashes: 3086939ee6407516c59b0ba3fbf555338f9d52f459bcab6337c0f00e91ea8456 stunnel-5.67.tar.gz a6bdc2a735eb34465d10e3c7e61f32d679ba29a68de8ea8034db79c0c8b328a3 stunnel-5.67-win64-installer.exe 893f53d6647900eb34041be8f21a21c052a31de3fb393a97627021a1ef2752f5 stunnel-5.67-android.zip Best regards, Mike

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"make cert" get "Error configuring OpenSSL modules"
by decatur93＠163.com 28 Oct '22

28 Oct '22

Hi, all. I have done "make && make install" under "sudo", then I got this when "make cert" --------------------------------------------------------------- make -C tools cert make[1]: Entering directory '/opt/stunnel-5.66/tools' ./makecert.sh . /usr /dev/urandom OpenSSL 1.1.1f 31 Mar 2020 1+0 records in 1+0 records out 256 bytes copied, 0.0001303 s, 2.0 MB/s Error configuring OpenSSL modules 139784943940928:error:25066067:DSO support routines:dlfcn_load:could not load the shared library:../crypto/dso/dso_dlfcn.c:118:filename(libproviders.so): libproviders.so: cannot open shared object file: No such file or directory 139784943940928:error:25070067:DSO support routines:DSO_load:could not load the shared library:../crypto/dso/dso_lib.c:162: 139784943940928:error:0E07506E:configuration file routines:module_load_dso:error loading dso:../crypto/conf/conf_mod.c:224:module=providers, path=providers 139784943940928:error:0E076071:configuration file routines:module_run:unknown module name:../crypto/conf/conf_mod.c:165:module=providers Certificate details: Can't open stunnel.pem for reading, No such file or directory 139707919738176:error:02001002:system library:fopen:No such file or directory:../crypto/bio/bss_file.c:69:fopen('stunnel.pem','r') 139707919738176:error:2006D080:BIO routines:BIO_new_file:no such file:../crypto/bio/bss_file.c:76: unable to load certificate /usr/bin/install -c -b -m 600 stunnel.pem /usr/local/etc/stunnel/stunnel.pem /usr/bin/install: cannot stat 'stunnel.pem': No such file or directory make[1]: *** [Makefile:579: cert] Error 1 make[1]: Leaving directory '/opt/stunnel-5.66/tools' make: *** [Makefile:894: cert] Error 2 ------------------------------------------------------------------ It seems I have no libproviders.so, but I have installed openssl. Can anyone help me? Thx.

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stunnel as simple TLS terminator to web backend -- works, but 1st response is blank page, after reload all's good ?
by PGNet Dev 15 Oct '22

15 Oct '22

I'm running [.] stunnel 5.66 on x86_64-redhat-linux-gnu platform [.] Compiled/running with OpenSSL 3.0.5 5 Jul 2022 on lsb_release -rd Description: Fedora release 36 (Thirty Six) Release: 36 uname -rm 5.19.15-201.fc36.x86_64 x86_64 it's setup to frontend terminate TLS in front of a bind9 nameserver instance's statistics (http-only) web server backend. it's a trivial config, cat /etc/stunnel/stunnel.conf debug = 5 syslog = yes [bind9-stats] accept = ns.example.com:10000 connect = 127.0.0.1:10001 sslVersion = TLSv1.3 ciphersuites = TLS_CHACHA20_POLY1305_SHA256 requireCert = yes verifyChain = yes verifyPeer = no CAfile = /usr/local/etc/stunnel/example_CA.CHAIN.crt.pem cert = /usr/local/etc/stunnel/ns.example.com.COMBINED.pem key = /usr/local/etc/stunnel/ns.example.com.server.key.pem sessionCacheSize = 1 sessionCacheTimeout = 360 and it does provide access, with no apparent/reported *error*, afaict. but, on initial access, i.e. first nav to the exposed site page, I get a blank page. simply RELOADING the browser page cures the problem. page display, with current/correct data -- as do all (sub)links on the page. this is repeatable behavior in multiple browsers (Firefox, Chromium, Chrome). so far i've not found any indication of an actual error -- only this 1st-page-visit-is-blank behavior, unique to my stunnel usage. other/heavier frontends have no such issue. odd, but not fatal. or even, apparently, problematic (so far, i think). is this a pebkac/config issue? or a known issue/bug? other?

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SSL Termination Issue
by Gary Jackson 15 Oct '22

15 Oct '22

We have an STunnel configuration running to take encrypted TLS traffic from customers and pass it to our application unencrypted. We have purchased a CA signed certificate, but we are receiving an error when negotiating. We have tried many searches/configurations with no progress. STunnel General Config ; ************************************************************************** ; * Global options * ; ************************************************************************** ; Debugging stuff (may be useful for troubleshooting) debug = debug output = stunnel.log ; Enable FIPS 140-2 mode if needed for compliance ;fips = yes ; Microsoft CryptoAPI engine allows for authentication with private keys ; stored in the Windows certificate store ; Each section using this feature also needs the "engineId = capi" option ;engine = capi ; You also need to disable TLS 1.2 or later, because the CryptoAPI engine ; currently does not support PSS ;sslVersionMin = TLSv1.2 sslVersionMax = TLSv1.2 ; TLSv1.1 requires security level 0 when compiled OpenSSL 3.0 and later ;securityLevel = 0 ciphersuites = TLS_CHACHA20_POLY1305_SHA256:TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256 ciphers = ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-DSS-AES256-GCM-SHA384:DHE-;RSA-AES256-GCM-SHA384:ECDH-RSA-AES256-GCM-SHA384:ECDH-ECDSA-AES256-GCM-SHA384:AES256-GCM-;SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:DHE-RSA-;AES128-GCM-SHA256:ECDH-RSA-AES128-GCM-SHA256:ECDH-ECDSA-AES128-GCM-SHA256:AES128-GCM-SHA256 curves = X25519:P-256:X448:P-521:P-384 ; The pkcs11 engine allows for authentication with cryptographic ; keys isolated in a hardware or software token ; MODULE_PATH specifies the path to the pkcs11 module shared library, ; such as softhsm2-x64.dll or opensc-pkcs11.dll ; IMPORTANT: A 64-bit stunnel requires 64-bit PKCS#11 modules ; Each section using this feature also needs the "engineId = pkcs11" option ;engine = pkcs11 ;engineCtrl = MODULE_PATH:softhsm2-x64.dll ;engineCtrl = PIN:1234 ; ************************************************************************** ; * Service defaults may also be specified in individual service sections * ; ************************************************************************** ; Enable support for the insecure SSLv3 protocol options = -NO_SSLv3 ; These options provide additional security at some performance degradation ;options = SINGLE_ECDH_USE ;options = SINGLE_DH_USE ; ************************************************************************** ; * Include all configuration file fragments from the specified folder * ; ************************************************************************** ;include = conf.d STunnel Service Specific Config ; TLS front-end to a web server [https] accept = 27015 connect = 172.31.4.10:9000 cert = mycert.pem key = mycert.pem ; "TIMEOUTclose = 0" is a workaround for a design flaw in Microsoft SChannel ; Microsoft implementations do not use TLS close-notify alert and thus they ; are vulnerable to truncation attacks TIMEOUTclose = 0 STunnel Debug 2022.10.15 11:16:08 LOG6[769]: TLSv1.2 ciphersuite: ECDHE-RSA-AES256-GCM-SHA384 (256-bit encryption) 2022.10.15 11:16:08 LOG3[769]: SSL_get_peer_tmp_key: Peer suddenly disconnected 2022.10.15 11:16:08 LOG7[769]: Compression: null, expansion: null 2022.10.15 11:16:08 LOG7[769]: Deallocating application specific data for session connect address 2022.10.15 11:16:08 LOG6[769]: s_connect: connecting x.x.x.x:9000 2022.10.15 11:16:08 LOG7[769]: s_connect: s_poll_wait x.x.x.x:9000: waiting 10 seconds 2022.10.15 11:16:08 LOG7[769]: FD=792 ifds=--- ofds=r-- 2022.10.15 11:16:08 LOG7[769]: FD=888 ifds=rwx ofds=--- 2022.10.15 11:16:08 LOG5[769]: s_connect: connected x.x.x.x:9000 2022.10.15 11:16:08 LOG6[769]: persistence: x.x.x.x:9000 cached 2022.10.15 11:16:08 LOG5[769]: Service [https] connected remote server from x.x.x.x:52720 2022.10.15 11:16:08 LOG7[769]: Setting remote socket options (FD=888) 2022.10.15 11:16:08 LOG7[769]: Option TCP_NODELAY set on remote socket 2022.10.15 11:16:08 LOG7[769]: Remote descriptor (FD=888) initialized 2022.10.15 11:16:09 LOG6[769]: SSL_read: Socket is closed 2022.10.15 11:16:09 LOG6[769]: TLS socket closed (SSL_read) 2022.10.15 11:16:09 LOG7[769]: Sent socket write shutdown Any assistance would be GREATLY appreciated! Thank you. _________________________________ Gary Jackson | Senior Systems Engineer Direct: 502.777.1940 IT GUY NETWORKS LLC | Certified Systems Consultants 14607 Lake Bluff Place Louisville, KY 40245 The information contained in this email, and in any accompanying documents, constitutes confidential information, which belongs to IT Guy Networks. This information is intended for the use of the individual(s) or entity named above. You are hereby notified that any disclosure, copying, distribution, or the taking of any action in reliance on this information, is strictly prohibited.

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Peer Suddenly Disconnects after Negotiating TLS
by Gary Jackson 13 Oct '22

13 Oct '22

I have a TLS Connection that appears to be established but then is terminating and not sure what would cause this. 2022.10.13 14:56:36 LOG5[12435]: Service [https] accepted connection from 97.72.232.10:62890 2022.10.13 14:56:36 LOG6[12435]: Peer certificate not required 2022.10.13 14:56:36 LOG6[12435]: TLS accepted: new session negotiated 2022.10.13 14:56:36 LOG6[12435]: TLSv1.2 ciphersuite: ECDHE-RSA-AES256-GCM-SHA384 (256-bit encryption) 2022.10.13 14:56:36 LOG3[12435]: SSL_get_peer_tmp_key: Peer suddenly disconnected 2022.10.13 14:56:36 LOG6[12435]: s_connect: connecting 172.31.4.10:9000 2022.10.13 14:56:36 LOG5[12435]: s_connect: connected 172.31.4.10:9000 2022.10.13 14:56:36 LOG6[12435]: persistence: 172.31.4.10:9000 cached 2022.10.13 14:56:36 LOG5[12435]: Service [https] connected remote server from 172.31.4.20:59907 2022.10.13 14:56:36 LOG6[12435]: SSL_read: Socket is closed 2022.10.13 14:56:36 LOG6[12435]: TLS socket closed (SSL_read) 2022.10.13 14:56:36 LOG5[12435]: Connection closed: 0 byte(s) sent to TLS, 0 byte(s) sent to socket Thanks in advance. _________________________________ Gary Jackson | Senior Systems Engineer Direct: 502.777.1940 IT GUY NETWORKS LLC | Certified Systems Consultants 14607 Lake Bluff Place Louisville, KY 40245 The information contained in this email, and in any accompanying documents, constitutes confidential information, which belongs to IT Guy Networks. This information is intended for the use of the individual(s) or entity named above. You are hereby notified that any disclosure, copying, distribution, or the taking of any action in reliance on this information, is strictly prohibited.

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SSL_read: ssl/record/rec_layer_s3.c:308: error:0A000126:SSL routines::unexpected eof while reading
by carango＠ingeniocarmelita.com 13 Oct '22

13 Oct '22

Hello I have the same problem, any solution? SSL_read: ssl/record/rec_layer_s3.c:308: error:0A000126:SSL routines::unexpected eof while reading

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32-bit windows download
by Ágnes Kakasi 27 Sep '22

27 Sep '22

Hi, I'm looking for help to download and install Stunnel on a laptop with 32-bit Windows 7. I have downloaded the available download file from the website (stunnel-5.66-win64-installer.exe) but the computer indicates it cannot open the file. I tried to find info on this and in the platform sections I found Stunnel can run on 32-bit, as well, but I don't know how to make it work. Can you please advise me on what the correct download file is and how to install it so that it works on this computer? Thank you in advance. Agnes

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error:0A000438:SSL routines::tlsv1 alert internal error
by johannwang＠ami.com 21 Sep '22

21 Sep '22

Hello, I am trying to use the xvncviewer on Ubuntu by VNC over stunnel, it will connect failed and print "xvncviewer: read: Connection reset by peer". The LOG on VNC server is here: 2012.01.01 00:21:58 LOG7[1]: Initializing application specific data for session authenticated 2012.01.01 00:21:58 LOG7[1]: SNI: no virtual services defined 2012.01.01 00:21:58 LOG7[1]: TLS state (accept): SSLv3/TLS read client hello 2012.01.01 00:21:58 LOG7[1]: TLS state (accept): SSLv3/TLS write server hello 2012.01.01 00:21:58 LOG7[1]: TLS state (accept): SSLv3/TLS write certificate 2012.01.01 00:21:58 LOG7[1]: TLS state (accept): SSLv3/TLS write key exchange 2012.01.01 00:21:58 LOG7[1]: TLS state (accept): SSLv3/TLS write certificate request 2012.01.01 00:21:58 LOG7[1]: TLS state (accept): SSLv3/TLS write server done 2012.01.01 00:21:58 LOG7[1]: TLS alert (read): fatal: internal error 2012.01.01 00:21:58 LOG3[1]: SSL_accept: ssl/record/rec_layer_s3.c:1584: error:0A000438:SSL routines::tlsv1 alert internal error 2012.01.01 00:21:58 LOG5[1]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket 2012.01.01 00:21:58 LOG7[1]: Deallocating application specific data for session connect address 2012.01.01 00:21:58 LOG7[1]: Local descriptor (FD=3) closed 2012.01.01 00:21:58 LOG7[1]: Service [vnc] finished (0 left) I am running Stunnel 5.63 Here is the configuration currently: stunnel.conf on VNC client: cert = /home/server.pem key = /home/privkey.pem [VNC] client = yes accept = 127.0.0.1:5901 connect = 172.31.100.121:5901 sslVersion = all verifyChain = yes CAfile = /home/server.pem checkIP = 172.31.100.121 stunnel.conf on VNC server: cert = /conf/server.pem ;key = /conf/certs/privkey.pem setuid = stunnel4 setgid = stunnel4 pid = /var/run/stunnel.pid socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 socket = a:TCP_NODELAY=1 debug = 7 foreground = yes client = no ciphers=AES256-SHA256:!RC4:HIGH:!MD5:!aNULL:!EDH:!AESGCM sslVersion = TLSv1.2 [vnc] accept = :::5901 connect = 5900 verify = 3 CAfile = /conf/server.pem Is this something I can remedy from the configuration, or is this something that requires modification? Thank you Johan

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v5.66: failing test 081
by Andreas Vetter 20 Sep '22

20 Sep '22

Hi, in open build system I get the following failing test, when building and testing stunnel 5.66: [ 45s] 081. Test IPv6 support [ 45s] [client] Read '2022.09.15 21:17:15 LOG6[0]: TLS fd: Connection reset by peer (104)' [ 45s] ...................................................................... failed Is this a stunnel problem or a problem with logging inside the build system? What can I do to get more verbose information during build? The test is working for a similar target OS (openSUSE_Tumbleweed) and not for this one (openSUSE:Factory). The difference is small, but sometimes not neglectible: openSUSE:Factory is the to be tested submissions, always in the flow. openSUSE_Tumbleweed is a tested working snapshot of Factory. Best regards, Andreas

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stunnel 5.66 released
by Michał Trojnara 11 Sep '22

11 Sep '22

Dear Users, I have released version 5.66 of stunnel. ### Version 5.66, 2022.09.11, urgency: MEDIUM * New features - OpenSSL 3.0 FIPS Provider support for Windows. * Bugfixes - Fixed building on machines without pkg-config. - Added the missing "environ" declaration for BSD-based operating systems. - Fixed the passphrase dialog with OpenSSL 3.0. Home page: https://www.stunnel.org/ Download: https://www.stunnel.org/downloads.html SHA-256 hashes: 558178704d1aa5f6883aac6cc5d6bbf2a5714c8a0d2e91da0392468cee9f579c stunnel-5.66.tar.gz 5fccb2e4db0d2e3c1adb26c3906585ac545baf88226f4f539b2dc43fe418a3ef stunnel-5.66-win64-installer.exe 3b1e30e060e16f6aa9a8ad1b1a6ba1210c165bf76bd01e4734cb4537e0717c09 stunnel-5.66-android.zip Best regards, Mike

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Stunnel Consulting
by Gary Jackson 10 Sep '22

10 Sep '22

I am looking for someone to assist with an stunnel configuration on windows that will accept TLS1.2 connections and then send them unencrypted to an IP and port. I would need to get it working within the next week or so and am available most times if scheduled. Thank you. Gary Jackson Sent from my mobile

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TLS 1.2 traffic on STunnel
by Gary Jackson 08 Sep '22

08 Sep '22

Good afternoon, I am trying to use Stunnel to accept traffic from a custom application using TLS 1.2 and a self signed cert and then send it to a back end application unencrypted. I want the configuration to only affect one listener on Stunnel and not all incoming ports. I am using Stunnel v.5.6 I am confused with all the documentation and what needs to be set in the config file for this use case. The config file currently has connections where it accepts traffic on one port and then directs it to another port internally but not with TLS 1.2. Thank you for all your knowledge and insight! _________________________________ Gary Jackson | Senior Systems Engineer

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Certificate Request's "Distinguished Names" list is empty when using CAPath (but not when using CAFile)
by david.rundqvist＠gmail.com 26 Aug '22

26 Aug '22

Hi, If I hash the client certificates and put them in a folder (with file names <hash>.0), and use the CAPath parameter on the server, together with verify=3, the server's Certificate Request message contains an empty list of "Distinguished Names". However, if I put the client certificates concatenated in a .pem file, and use the CAFile parameter on the server, the Certificate Request message does contain the Distinguished Names. Is this the correct behavior? I thought CAFile and CAPath worked more or less in the same way, but perhaps the Certificate Request message is implemented differently, depending on if you use CAFile or CAPath? My preferred way is to use CAPath: Is there some way I can get the Distinguished Names not to be empty, when using CAPath? I'm on Windows, using stunnel version 5.49, currently. Thanks in advance! Kind regards, /David

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looking to pay for stunnel support
by jkorman＠pcvisions1.com 24 Aug '22

24 Aug '22

I have an issue with a program that is 9 years old that uses old stunnel for email forwarding of automated alerts. I would gladly pay for support for assistance configuring the newest version of stunnel. My issue is that present configuration is sending smtp at tls 1.0 which is getting rejected. Please send me your info via email and I will promptly respond Joe Korman

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FIPS-enabled Windows installer of stunnel
by Vadim Loevski 22 Aug '22

22 Aug '22

Hi, I would appreciate it if you let me know how I could obtain a FIPS-enabled Windows 64 bit installer of stunnel. Regards, Vadim

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Stunnel is throwing Timeout connect and Timeout closed error
by Ferdous K 16 Aug '22

16 Aug '22

Hello, I have been using Stunnel 3.5.44 (latest for Ubuntu 18) to connect to my remote load balancer which serves traffic to several backend nodes. After recent O/S update, I have noticed one weird issue. I am seeing frequent TIMEOUTconnect and TIMEOUTclosed exceeded errors when stunnel service tries to connect to backend nodes via load balancer in round robin mode. If I replace load balancer or multiple backends (to rule out DNS issue) entries: connect = remote-load-balancer:8080 Or connect = remote-backend-node1:8080 connect = remote-backend-node2:8080 With single backend entry like this: connect = remote-backend-node1:8080 Or, connect = remote-backend-node2:8080 Then those errors go away. I have tested on multiple servers with different backends and timeout configuration and all are showing same issues so the problem seems like not related to specific server of backend. Any idea what could cause this issue? Thanks in advance, Ferdous Reference: https://launchpad.net/ubuntu/bionic/+package/stunnel4 Stunnel sample config: pid = /var/run/stunnel4/stunnel.pid output = /var/log/stunnel4/stunnel.log socket = l:SO_KEEPALIVE=1 socket = r:SO_KEEPALIVE=1 socket = r:TCP_KEEPIDLE=120 socket = r:TCP_KEEPINTVL=30 socket = r:TCP_KEEPCNT=6 socket = l:TCP_KEEPIDLE=120 socket = l:TCP_KEEPINTVL=30 socket = l:TCP_KEEPCNT=6 [remote] client = yes accept = 127.0.0.1:6500 connect = remote-load-balancer:8080 cert = /opt/service/etc/cert.d/remote.crt key = /opt/service/etc/key.d/remote.key sslVersion = TLSv1.2 debug = info verifyChain = no verifyPeer = no

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