stunnel-users July 2021

8 participants
8 discussions

older browsers, stunnel and privoxy
by kovacs janos 04 Mar '24

04 Mar '24

sorry to bother, im trying to make older browsers be able to display TLS 1.1 and TLS 1.2 sites. i heard stunnel cant be configured to always forward to the current site address dynamically, thats why i would use privoxy. the browser is configured to send to: 127.0.0.1 443 stunnel config has this at the end: [Tunnel_in] client = yes accept = 127.0.0.1:443 connect = 127.0.0.1:8118 verifyChain = yes CAfile = ca-certs.pem checkHost = localhost 127.0.0.1:8118 is the privoxy address. this is what stunnel writes: LOG5[main]: Configuration successful LOG5[0]: Service [Tunnel_in] accepted connection from 127.0.0.1:3261 LOG5[0]: s_connect: connected 127.0.0.1:8118 LOG5[0]: Service [Tunnel_in] connected remote server from 127.0.0.1:3262 and the browser infinitely loads, and never loads anything or leaves the page. if i remove the last 3 lines, its the same just with this line added: LOG4[main]: Service [Tunnel_in] needs authentication to prevent MITM attacks but it doesnt give an error or anything. with a configuration like: [Tunnel_out] client = no accept = 127.0.0.1:443 connect = 127.0.0.1:8118 cert = stunnel.pem this is what it gives: LOG5[3]: Service [Tunnel_out] accepted connection from 127.0.0.1:3294 LOG3[3]: SSL_accept: 1407609B: error:1407609B:SSL routines:SSL23_GET_CLIENT_HELLO:https proxy request LOG5[3]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket and browser gives a server not found error immediately. im not even sure if i should use client or server configuration in a case like this, but none of them works anyway. all i would need is for my browser to get the pages decrypted, or at least in less than TLS1.1. like how on newipnow.com i can access sites with any encryption, since they are sent to the browser without encryption. the browser just gives an "unencrypted tunnel" warning, which is how i found stunnel, and which is exactly what i need, just locally.

8 41

TPM based mutual tls authentication
by Nyiri, Gabor (Nokia - HU/Budapest) 07 Nov '23

07 Nov '23

Hi, Can you help me how to configure stunnel client to use TPM for mutual TLS authentication? I want to connect with mTLS to a remote server then make this connection available for localhost without mTLS. Thanks for your help in advance! Here is my configuration so far without TPM: debug = debug output = /tmp/stunnel.log foreground = yes [mtls_client] client = yes accept = 127.0.0.1:12019 sni = server-with-mtls.example.com checkHost = server-with-mtls.example.com connect = 1.2.3.4:443 verifyChain = yes CApath = /etc/ssl/certs/ cert = client.crt key = client.key Thanks & br, Gábor Nyíri,

2 1

protocol = proxy with redirect
by Rob Hoes 15 Sep '21

15 Sep '21

Hi, I am using client certificate verification with the redirect option, so that the connection gets transferred to a separate socket in case the certificate is not accepted (rather than dropping the connection). This works well, unless I add the option “protocol = proxy” in order to get the client’s TCP params passed on. In this case, the redirect option seems to be ignored. Are the “redirect” and “protocol = proxy” options incompatible with one another? Is there an alternative? Thanks, Rob

2 1

Unexpected socket close while sending mail
by zfefm＠gmx.de 27 Jul '21

27 Jul '21

Hi, since several days I try to get stunnel working to add TLS1.2 or higher support to my outdated email client program (Applemail 4.6) as my service provider will stop supporting the old protocols soon. The protocol of stunnel looks as if the connection gets established well. But as soon I want to send a mail my mail program tries for 10-15s to send an then gives up. In the stunnel protocol (time stamp 16:54:22) the server seems to accept the connection, but about 10-15s later I get: Unexpected socket close (s_read) Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket Any ideas what could be the problem? Thanks. conf and protocol attached. conf: setuid = nobody setgid = nogroup foreground = yes debug = 7 output = /usr/local/etc/stunnel/stunnel.log [strato-pop3] client = yes verifyChain = yes accept = 127.0.0.1:110 connect = pop3.strato.de:995 CApath = /usr/local/etc/stunnel/ cert = /usr/local/etc/stunnel/stunnel.pem checkHost = pop3.strato.de protocol = pop3 [strato-smtp] client = yes verifyChain = yes accept = 127.0.0.1:25 connect = smtp.strato.de:465 checkHost = smtp.strato.de CApath = /usr/local/etc/stunnel/ cert = /usr/local/etc/stunnel/stunnel.pem protocol = smtp protocol : 2021.07.22 16:53:49 LOG6[ui]: Initializing inetd mode configuration 2021.07.22 16:53:49 LOG7[ui]: Clients allowed=125 2021.07.22 16:53:49 LOG5[ui]: stunnel 5.59 on x86_64-apple-darwin10.8.0 platform 2021.07.22 16:53:49 LOG5[ui]: Compiled/running with OpenSSL 1.1.1k 25 Mar 2021 2021.07.22 16:53:49 LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI Auth:LIBWRAP 2021.07.22 16:53:49 LOG7[ui]: errno: (*__error()) 2021.07.22 16:53:49 LOG6[ui]: Initializing inetd mode configuration 2021.07.22 16:53:49 LOG5[ui]: Reading configuration from file /usr/local/etc/stunnel/stunnel.conf 2021.07.22 16:53:49 LOG5[ui]: UTF-8 byte order mark detected 2021.07.22 16:53:49 LOG5[ui]: FIPS mode disabled 2021.07.22 16:53:49 LOG6[ui]: Compression enabled: 0 methods 2021.07.22 16:53:49 LOG7[ui]: No PRNG seeding was required 2021.07.22 16:53:49 LOG6[ui]: Initializing service [strato-pop3] 2021.07.22 16:53:49 LOG6[ui]: stunnel default security level set: 2 2021.07.22 16:53:49 LOG7[ui]: Ciphers: HIGH:!aNULL:!SSLv2:!DH:!kDHEPSK 2021.07.22 16:53:49 LOG7[ui]: TLSv1.3 ciphersuites: TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256 2021.07.22 16:53:49 LOG7[ui]: TLS options: 0x02100004 (+0x00000000, -0x00000000) 2021.07.22 16:53:49 LOG6[ui]: Loading certificate from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:49 LOG6[ui]: Certificate loaded from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:49 LOG6[ui]: Loading private key from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:49 LOG6[ui]: Private key loaded from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:49 LOG7[ui]: Private key check succeeded 2021.07.22 16:53:49 LOG6[ui]: DH initialization skipped: client section 2021.07.22 16:53:49 LOG7[ui]: ECDH initialization 2021.07.22 16:53:49 LOG7[ui]: ECDH initialized with curves X25519:P-256:X448:P-521:P-384 2021.07.22 16:53:49 LOG6[ui]: Initializing service [strato-smtp] 2021.07.22 16:53:50 LOG6[ui]: stunnel default security level set: 2 2021.07.22 16:53:50 LOG7[ui]: Ciphers: HIGH:!aNULL:!SSLv2:!DH:!kDHEPSK 2021.07.22 16:53:50 LOG7[ui]: TLSv1.3 ciphersuites: TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256 2021.07.22 16:53:50 LOG7[ui]: TLS options: 0x02100004 (+0x00000000, -0x00000000) 2021.07.22 16:53:50 LOG6[ui]: Loading certificate from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:50 LOG6[ui]: Certificate loaded from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:50 LOG6[ui]: Loading private key from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:50 LOG6[ui]: Private key loaded from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:50 LOG7[ui]: Private key check succeeded 2021.07.22 16:53:50 LOG6[ui]: DH initialization skipped: client section 2021.07.22 16:53:50 LOG7[ui]: ECDH initialization 2021.07.22 16:53:50 LOG7[ui]: ECDH initialized with curves X25519:P-256:X448:P-521:P-384 2021.07.22 16:53:50 LOG5[ui]: Configuration successful 2021.07.22 16:53:50 LOG7[ui]: Deallocating deployed section defaults 2021.07.22 16:53:50 LOG7[ui]: Binding service [strato-pop3] 2021.07.22 16:53:50 LOG7[ui]: Listening file descriptor created (FD=8) 2021.07.22 16:53:50 LOG7[ui]: Setting accept socket options (FD=8) 2021.07.22 16:53:50 LOG7[ui]: Option SO_REUSEADDR set on accept socket 2021.07.22 16:53:50 LOG6[ui]: Service [strato-pop3] (FD=8) bound to 127.0.0.1:110 2021.07.22 16:53:50 LOG7[ui]: Binding service [strato-smtp] 2021.07.22 16:53:50 LOG7[ui]: Listening file descriptor created (FD=10) 2021.07.22 16:53:50 LOG7[ui]: Setting accept socket options (FD=10) 2021.07.22 16:53:50 LOG7[ui]: Option SO_REUSEADDR set on accept socket 2021.07.22 16:53:50 LOG6[ui]: Service [strato-smtp] (FD=10) bound to 127.0.0.1:25 2021.07.22 16:53:50 LOG7[ui]: No pid file being created 2021.07.22 16:53:50 LOG7[cron]: Cron thread initialized 2021.07.22 16:53:50 LOG6[cron]: Executing cron jobs 2021.07.22 16:53:50 LOG6[cron]: Cron jobs completed in 0 seconds 2021.07.22 16:53:50 LOG7[cron]: Waiting 86400 seconds 2021.07.22 16:54:22 LOG7[ui]: Found 1 ready file descriptor(s) 2021.07.22 16:54:22 LOG7[ui]: FD=4 events=0x1 revents=0x0 2021.07.22 16:54:22 LOG7[ui]: FD=8 events=0x1 revents=0x1 2021.07.22 16:54:22 LOG7[ui]: FD=10 events=0x1 revents=0x0 2021.07.22 16:54:22 LOG7[ui]: Service [strato-pop3] accepted (FD=3) from 127.0.0.1:49864 2021.07.22 16:54:22 LOG7[0]: Service [strato-pop3] started 2021.07.22 16:54:22 LOG7[0]: Setting local socket options (FD=3) 2021.07.22 16:54:22 LOG7[0]: Option TCP_NODELAY set on local socket 2021.07.22 16:54:22 LOG5[0]: Service [strato-pop3] accepted connection from 127.0.0.1:49864 2021.07.22 16:54:22 LOG6[0]: s_connect: connecting 81.169.145.131:995 2021.07.22 16:54:22 LOG7[0]: s_connect: s_poll_wait 81.169.145.131:995: waiting 10 seconds 2021.07.22 16:54:22 LOG7[0]: FD=6 events=0x1 revents=0x0 2021.07.22 16:54:22 LOG7[0]: FD=13 events=0x5 revents=0x0 2021.07.22 16:54:22 LOG5[0]: s_connect: connected 81.169.145.131:995 2021.07.22 16:54:22 LOG5[0]: Service [strato-pop3] connected remote server from 192.168.17.130:49865 2021.07.22 16:54:22 LOG7[0]: Setting remote socket options (FD=13) 2021.07.22 16:54:22 LOG7[0]: Option TCP_NODELAY set on remote socket 2021.07.22 16:54:22 LOG7[0]: Remote descriptor (FD=13) initialized 2021.07.22 16:55:22 LOG3[0]: Unexpected socket close (s_read) 2021.07.22 16:55:22 LOG5[0]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket 2021.07.22 16:55:22 LOG7[0]: Remote descriptor (FD=13) closed 2021.07.22 16:55:22 LOG7[0]: Local descriptor (FD=3) closed 2021.07.22 16:55:22 LOG7[0]: Service [strato-pop3] finished (0 left) 2021.07.22 16:55:22 LOG7[0]: str_stats: 1 block(s), 32 data byte(s), 90 control byte(s) 2021.07.22 16:55:22 LOG7[0]: str_stats: 32 byte(s) at network.c:735

2 3

Equivalence of verify=2
by Yann RESCOURIO 22 Jul '21

22 Jul '21

Hello I would like to authenticate a server with only its CA file. What is the equivalence of verify=2 ? requireCert = yes verifyChain = no verifyPeer = yes Regards Yann

3 5

idea: linux stunnel mini-GUI
by Dmitry Bakshaev 13 Jul '21

13 Jul '21

we need start stunnel on linux desktop by ordinary user (like on windows): 1 click stunnel icon on system menu 2 enter user certificate password 3 use opened tunnels with users applications 4 on desktop session ends close all tunnels make XDG menu entry file: [Desktop Entry] Type=Application Name=stunnel Categories=Network; GenericName=TLS/SSL - Port Wrapper Comment[ru_RU]=Секретный туннель Icon=stunnel Exec=/usr/bin/stunnel Terminal=true X-KeepTerminal=true but only problem is how stunnel react on signals: HUP is daemon's "reload config". in X-session HUP signal is "session end" and stunnel is not exited on closing terminal or logout. attached patch change this behavior: if "foreground=yes" specified in stunnel.conf HUP signal is treated as TERM and stunnel exited. foreground=yes is "debug" or "desktop" mode of stunnel. XDG-desktop file and icon file may be included in default stunnel distributions.

1 0

Difficulty to select exact Cipher
by Sachin Deshmukh 12 Jul '21

12 Jul '21

Hello Together, I had been trying to use a stunnel to set PSK encrypted TLS. Below is my conf file. [client] client = yes accept = 127.0.0.1:8888 connect = 192.168.1.100:443 ciphers = PSK-AES128-CBC-SHA256 PSKsecrets = /data/dummy.txt I can see communication, but client e.g. Stunnel from Client side offer several other cipher in addition to exact one which is expected as per conf. I wish PSK-AES128-CBC-SHA256 (0x00ae) But I see the list below in actual communication. [image: image.png] Please let me know 1 .how we can inform stunnel to use exact and only 1 cipher provided in the conf file. Or 2. How can we state hex id instead of string. If I see a cipher list, with the same keyword as a part or whole there are more than 1 ciphers, I suppose this causes stunnel to take a list as per string match. ECDHE-PSK-AES128-CBC-SHA256 TLSv1 Kx=ECDHEPSK Au=PSK Enc=AES(128) Mac=SHA256 RSA-PSK-AES128-CBC-SHA256 TLSv1 Kx=RSAPSK Au=RSA Enc=AES(128) Mac=SHA256 DHE-PSK-AES128-CBC-SHA256 TLSv1 Kx=DHEPSK Au=PSK Enc=AES(128) Mac=SHA256 *PSK-AES128-CBC-SHA256 * TLSv1 Kx=PSK Au=PSK Enc=AES(128) Mac=SHA256 Can we make a stunnel to select only one exact cipher?

1 0

curl 7.61 exit status 8 from stunnel service of tls1
by kmx1818＠gmail.com 09 Jul '21

09 Jul '21

Hello all, For a remote tls1 web service : $ # openssl s_client -connect myremote:7002 -tls1 CONNECTED(00000004) depth=0 CN = xxx, OU = xxx, O = xxx, C = xxx verify error:num=18:self signed certificate verify return:1 depth=0 CN = xxx, OU = xxx, O = xxx, C = xxx verify return:1 --- Certificate chain ... --- Server certificate -----BEGIN CERTIFICATE----- MIIC8zCCAdsCBGCvjhEwDQYJKoZIhvcNAQEFBQAwPjEOMAwGA1UEAxMFRUZXRUIx ... QG9sNNhQW65rRVmdqy/g0cBbLKRKhmRCS+ajRIzBcO9ZmMe42TES -----END CERTIFICATE----- subject=XXX issuer=XXX --- No client certificate CA names sent --- SSL handshake has read 889 bytes and written 509 bytes --- New, TLSv1/SSLv3, Cipher is RC4-MD5 Server public key is 2048 bit Secure Renegotiation IS NOT supported Compression: NONE Expansion: NONE No ALPN negotiated SSL-Session: Protocol : TLSv1 Cipher : RC4-MD5 Session-ID: 2D9F8D8833A459C16C1D01F0C92F8EB7 Session-ID-ctx: Master-Key: 1BF68D1AAEEC291A60252ECD63C374661FBBE028FB39A75DDA29E4E3FB6FE34CFC80F875F9E16F9D7C840F185757F583 Key-Arg : None PSK identity: None PSK identity hint: None SRP username: None Start Time: 1625842735 Timeout : 7200 (sec) Verify return code: 18 (self signed certificate) --- closed $ I can test it alright with an "old" curl $ curl --version curl 7.15.4 (sparc-sun-solaris2.9) libcurl/7.15.4 OpenSSL/0.9.7g zlib/1.2.3 Protocols: tftp ftp telnet dict ldap http file https ftps Features: IPv6 Largefile NTLM SSL libz ...like this $ curl -skL https://myremote:7002/MyWebService?WSDL <?xml version="1.0" encoding="UTF-8"?> ... </soap:address> </port> </service> </definitions> I want to tls1.2-enable myremote:7002 with stunnel, and run a tls1.2 curl instead. My stunnel installation $ /opt/csw/bin/stunnel -version Initializing inetd mode configuration stunnel 5.59 on sparc-sun-solaris2.10 platform Compiled with OpenSSL 1.0.2u 20 Dec 2019 Running with OpenSSL 1.0.2o 27 Mar 2018 Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI Auth:LIBWRAP Global options: RNDbytes = 1024 RNDfile = /dev/urandom RNDoverwrite = yes Service-level options: ciphers = HIGH:!aNULL:!SSLv2:!DH:!kDHEPSK curves = prime256v1 debug = daemon.notice logId = sequential options = NO_SSLv2 I start it with this service config: [my12] client = no accept = 7002 connect = myremote:7002 cert = /etc/opt/csw/stunnel/stunnel.crt key = /etc/opt/csw/stunnel/stunnel.key sslVersion = TLSv1.2 debug = 7 and test it with a fairly recent curl $ /opt/csw/bin/curl --version curl 7.61.0 (sparc-sun-solaris2.10) libcurl/7.61.0 OpenSSL/1.0.2o zlib/1.2.8 libidn2/2.0.4 libpsl/0.19.1 (+libidn2/2.0.4) Release-Date: 2018-07-11 Protocols: dict file ftp ftps gopher http https imap imaps pop3 pop3s rtsp smb smbs smtp smtps telnet tftp Features: AsynchDNS IDN IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP UnixSockets HTTPS-proxy PSL Metalink Alas, the recent curl call $ /opt/csw/bin/curl -skL https://myremote:7002/MyWebService?WSDL ...fails with exit status 23 In verbose mode we get * Trying 127.0.0.1... * TCP_NODELAY set * Failed to set TCP_KEEPALIVE on fd 4 * Connected to localhost (127.0.0.1) port 7002 (#0) * ALPN, offering http/1.1 * Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH * successfully set certificate verify locations: * CAfile: none CApath: /etc/opt/csw/ssl/certs * TLSv1.2 (OUT), TLS header, Certificate Status (22): * TLSv1.2 (OUT), TLS handshake, Client hello (1): * TLSv1.2 (IN), TLS handshake, Server hello (2): * TLSv1.2 (IN), TLS handshake, Certificate (11): * TLSv1.2 (IN), TLS handshake, Server key exchange (12): * TLSv1.2 (IN), TLS handshake, Server finished (14): * TLSv1.2 (OUT), TLS handshake, Client key exchange (16): * TLSv1.2 (OUT), TLS change cipher, Client hello (1): * TLSv1.2 (OUT), TLS handshake, Finished (20): * TLSv1.2 (IN), TLS change cipher, Client hello (1): * TLSv1.2 (IN), TLS handshake, Finished (20): * SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384 * ALPN, server did not agree to a protocol * Server certificate: * subject: C=TS; ST=Westfarthing; L=Hobbiton; O=Thorin and Company; OU=Burglars; CN=ahost.theshire.net; emailAddress=bilbo(a)theshire.net * start date: Jun 30 09:24:25 2021 GMT * expire date: Jun 30 09:24:25 2022 GMT * issuer: C=TS; ST=Westfarthing; L=Hobbiton; O=Thorin and Company; OU=Burglars; CN=ahost.theshire.net; emailAddress=bilbo(a)theshire.net * SSL certificate verify result: self signed certificate (18), continuing anyway. > GET /MyWebService?WSDL HTTP/1.1 > Host: localhost:7002 > User-Agent: curl/7.61.0 > Accept: */* > Warning: Binary output can mess up your terminal. Use "--output -" to tell Warning: curl to output it to your terminal anyway, or consider "--output Warning: <FILE>" to save to a file. * Failed writing body (0 != 7) * Closing connection 0 * TLSv1.2 (OUT), TLS alert, Client hello (1): $ I tried various curl flags - nothing works. In the meantime stunnel logs no errors Jul 9 16:16:45 acuapd30 stunnel: [ID 801593 daemon.notice] LOG5[18]: Service [my12] accepted connection from 127.0.0.1:39165 Jul 9 16:16:45 acuapd30 stunnel: [ID 801593 daemon.notice] LOG5[18]: s_connect: connected 10.240.28.69:7002 Jul 9 16:16:45 acuapd30 stunnel: [ID 801593 daemon.notice] LOG5[18]: Service [my12] connected remote server from xxx.yyy.zzz.www:39166 Jul 9 16:17:10 acuapd30 stunnel: [ID 801593 daemon.notice] LOG5[18]: Connection closed: 7 byte(s) sent to TLS, 116 byte(s) sent to socket What am i doing wrong!? Thanks in advance!

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stunnel-users July 2021