- stunnel-users - stunnel.org

SMTP out via Comcast stopped working
by Carlos Rodriguez 30 Nov '19

30 Nov '19

All: I have had this setup working fine since Comcast blocked port 25 and recently stopped working. This is a MS Small Business Server 2003 with Exchange, I know, old and obsolete but I would like to keep it working until I migrate to Linux. Anyway, right now I also have my desktop, Win10, using the same SMTP settings for the Acronis backup event results and it can send me emails just fine, just tested this. So it is not my firewall or Comcast. I'm missing something in the settings of stunnel. Below are my settings and log file. Any suggestions will be appreciated. Carlos taskbar = yes [SSLsmtp] client = yes accept = localhost:555 connect = smtp.comcast.net:587 protocol = smtp CAfile = ca-certs.pem protocolUsername = verifiedusername protocolPassword = verifiedpassword debug = 7 ================================================ 2019.11.29 16:31:24 LOG5[main]: stunnel 5.49 on x86-pc-msvc-1500 platform 2019.11.29 16:31:24 LOG5[main]: Compiled/running with OpenSSL 1.0.2p-fips 14 Aug 2018 2019.11.29 16:31:24 LOG5[main]: Threading:WIN32 Sockets:SELECT,IPv6 TLS:ENGINE,FIPS,OCSP,PSK,SNI 2019.11.29 16:31:24 LOG5[main]: Reading configuration from file stunnel.conf 2019.11.29 16:31:24 LOG5[main]: UTF-8 byte order mark detected 2019.11.29 16:31:24 LOG5[main]: FIPS mode disabled 2019.11.29 16:31:26 LOG4[main]: Service [SSLsmtp] needs authentication to prevent MITM attacks 2019.11.29 16:31:26 LOG5[main]: Configuration successful 2019.11.29 16:34:12 LOG7[0]: Service [SSLsmtp] started 2019.11.29 16:34:12 LOG7[0]: Setting local socket options (FD=264) 2019.11.29 16:34:12 LOG7[0]: Option TCP_NODELAY set on local socket 2019.11.29 16:34:12 LOG5[0]: Service [SSLsmtp] accepted connection from 127.0.0.1:1268 2019.11.29 16:34:12 LOG6[0]: s_connect: connecting 96.114.157.81:587 2019.11.29 16:34:12 LOG7[0]: s_connect: s_poll_wait 96.114.157.81:587: waiting 10 seconds 2019.11.29 16:34:12 LOG5[0]: s_connect: connected 96.114.157.81:587 2019.11.29 16:34:12 LOG5[0]: Service [SSLsmtp] connected remote server from 10.10.10.99:1269 2019.11.29 16:34:12 LOG7[0]: Setting remote socket options (FD=288) 2019.11.29 16:34:12 LOG7[0]: Option TCP_NODELAY set on remote socket 2019.11.29 16:34:12 LOG7[0]: Remote descriptor (FD=288) initialized 2019.11.29 16:34:12 LOG7[0]: <- 220 resomta-po-02v.sys.comcast.net resomta-po-02v.sys.comcast.net ESMTP server ready 2019.11.29 16:34:12 LOG7[0]: -> 220 resomta-po-02v.sys.comcast.net resomta-po-02v.sys.comcast.net ESMTP server ready 2019.11.29 16:34:12 LOG7[0]: -> EHLO localhost 2019.11.29 16:34:12 LOG7[0]: <- 250-resomta-po-02v.sys.comcast.net hello [71.206.38.109], pleased to meet you 2019.11.29 16:34:12 LOG7[0]: <- 250-HELP 2019.11.29 16:34:12 LOG7[0]: <- 250-SIZE 36700160 2019.11.29 16:34:12 LOG7[0]: <- 250-ENHANCEDSTATUSCODES 2019.11.29 16:34:12 LOG7[0]: <- 250-8BITMIME 2019.11.29 16:34:12 LOG7[0]: <- 250-STARTTLS 2019.11.29 16:34:12 LOG7[0]: <- 250 OK 2019.11.29 16:34:12 LOG7[0]: -> STARTTLS 2019.11.29 16:34:12 LOG7[0]: <- 220 2.0.0 Ready to start TLS 2019.11.29 16:34:12 LOG6[0]: SNI: sending servername: smtp.comcast.net 2019.11.29 16:34:12 LOG6[0]: Peer certificate not required 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): before/connect initialization 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv2/v3 write client hello A 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 read server hello A 2019.11.29 16:34:12 LOG6[0]: Certificate verification disabled 2019.11.29 16:34:12 LOG6[0]: Certificate verification disabled 2019.11.29 16:34:12 LOG6[0]: Certificate verification disabled 2019.11.29 16:34:12 LOG6[0]: Certificate verification disabled 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 read server certificate A 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 read server key exchange A 2019.11.29 16:34:12 LOG6[0]: Client certificate not requested 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 read server done A 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 write client key exchange A 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 write change cipher spec A 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 write finished A 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 flush data 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 read server session ticket A 2019.11.29 16:34:12 LOG7[0]: TLS state (connect): SSLv3 read finished A 2019.11.29 16:34:12 LOG7[0]: New session callback 2019.11.29 16:34:12 LOG7[0]: Peer certificate was cached (6814 bytes) 2019.11.29 16:34:12 LOG6[0]: Session id: 11C16B28FFB4A3A4EDC164CA65C3F20A896BF61C4D3B09F571E4285CFD0C82B3 2019.11.29 16:34:12 LOG7[0]: 1 client connect(s) requested 2019.11.29 16:34:12 LOG7[0]: 1 client connect(s) succeeded 2019.11.29 16:34:12 LOG7[0]: 0 client renegotiation(s) requested 2019.11.29 16:34:12 LOG7[0]: 0 session reuse(s) 2019.11.29 16:34:12 LOG6[0]: TLS connected: new session negotiated 2019.11.29 16:34:12 LOG6[0]: TLSv1.2 ciphersuite: ECDHE-RSA-AES256-GCM-SHA384 (256-bit encryption) 2019.11.29 16:34:12 LOG7[0]: Compression: null, expansion: null 2019.11.29 16:34:12 LOG7[0]: -> AUTH PLAIN AGNhcmxvc3JyQGNvbWNhc3QubmV0AFNveTFjYXJpZHVybw== 2019.11.29 16:34:12 LOG7[0]: <- 500 command unrecognized 2019.11.29 16:34:12 LOG3[0]: PLAIN Authentication Failed 2019.11.29 16:34:12 LOG5[0]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket 2019.11.29 16:34:12 LOG7[0]: Remote descriptor (FD=288) closed 2019.11.29 16:34:12 LOG7[0]: Local descriptor (FD=264) closed 2019.11.29 16:34:12 LOG7[0]: Service [SSLsmtp] finished (0 left)

2 1

undefined reference to `CRYPTO_set_id_callback'
by Somchai Smythe 29 Nov '19

29 Nov '19

How do I fix this? gcc -DHAVE_CONFIG_H -I. -I/usr/kerberos/include -I/usr/include -DLIBDIR='"/usr/lib/stunnel"' -DCONFDIR='"/etc/stunnel"' -O3 -m64 -march=x86-64 -mtune=generic -pipe -std=gnu17 -pthread -Wall -Wextra -Wpedantic -Wformat=2 -Wconversion -Wno-long-long -Wno-deprecated-declarations -fPIE -fstack-protector -D_FORTIFY_SOURCE=2 -MT stunnel-sthreads.o -MD -MP -MF .deps/stunnel-sthreads.Tpo -c -o stunnel-sthreads.o `test -f 'sthreads.c' || echo './'`sthreads.c sthreads.c: In function 'thread_id_init': sthreads.c:116:5: warning: implicit declaration of function 'CRYPTO_set_id_callback'; did you mean 'CRYPTO_set_locking_callback'? [-Wimplicit-function-declaration] 116 | CRYPTO_set_id_callback(stunnel_thread_id); | ^~~~~~~~~~~~~~~~~~~~~~ | CRYPTO_set_locking_callback ... libtool: link: ( cd ".libs" && rm -f "libstunnel.la" && ln -s "../libstunnel.la" "libstunnel.la" ) /usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: stunnel-sthreads.o: in function `sthreads_init': sthreads.c:(.text+0xb0): undefined reference to `CRYPTO_set_id_callback' /usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: stunnel-sthreads.o: in function `thread_id_init': sthreads.c:(.text+0x3a): undefined reference to `CRYPTO_set_id_callback' collect2: error: ld returned 1 exit status make[2]: *** [Makefile:550: stunnel] Error 1 I'm using openssl-1.1.1d if it matters.

2 4

"Address already in use" error
by Phil Smith III 25 Nov '19

25 Nov '19

Rebooted (Windows 7, fully patched) today and stunnel wouldn't start, said "Address already in use". Hmm.nothing much has changed. Rebooted again, same. Tinkered a bit, didn't see anything that looked meaningful. Went to look at deleted digests of this list, saw new version out, installed that, now it's happy. So.a mystery, at least to me; posting in case it helps someone else! .phsiii

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segfault with v5.55
by Francois Robinette 22 Nov '19

22 Nov '19

I've seen other having the same issue without resolution so far... But we do have the same issue: stunnel[7886]: segfault at 21 ip 00007f70aa1efcea sp 00007f6fa7797978 error 6 in libpthread-2.12.so[7f70aa1e5000+17000]

2 4

Windows 10 stunnel does not accept options
by Clodoaldo Neto 22 Nov '19

22 Nov '19

Any option I try in stunnel 5.55 results the same. Say: PS C:\Program Files (x86)\stunnel\bin> .\stunnel \path\to\config\file [ ] Running on Windows 6.2 [ ] No limit detected for the number of clients [.] stunnel 5.55 on x64-pc-mingw32-gnu platform [.] Compiled/running with OpenSSL 1.1.1c 28 May 2019 [.] Threading:WIN32 Sockets:SELECT,IPv6 TLS:ENGINE,OCSP,PSK,SNI [ ] errno: (*_errno()) [ ] GUI message loop initialized [ ] Running on Windows 6.2 [.] Reading configuration from file stunnel.conf [.] UTF-8 byte order mark detected [ ] Compression disabled [ ] No PRNG seeding was required [ ] Initializing service [ssh] [ ] Ciphers: HIGH:!aNULL:!SSLv2:!DH:!kDHEPSK [ ] TLSv1.3 ciphersuites: TLS_CHACHA20_POLY1305_SHA256:TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256 [ ] TLS options: 0x02100004 (+0x00000000, -0x00000000) [ ] No certificate or private key specified [:] Service [ssh] needs authentication to prevent MITM attacks [ ] Initializing service [gmail-imap] [!] Service [gmail-imap]: TLS server needs a certificate [ ] Deallocating section defaults [!] Server is down Same with PS C:\Program Files (x86)\stunnel\bin> .\stunnel nonexistent or PS C:\Program Files (x86)\stunnel\bin> .\stunnel -help Regards, Clodoaldo

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Re: [stunnel-users] Stunnel traffic fails to go via proxy set in
by Andrew Krause 11 Nov '19

11 Nov '19

Hi Jai, If your proxy supports the HTTP CONNECT method, you can try revising your settings to this: [KG_Self-Checkout] key = client.pem cert = client.pem client = yes accept = 127.0.0.1:5001 connect = wproxy.qut.edu.au:3128 protocolHost = ap01.alma.exlibrisgroup.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 sslVersion = TLSv1.2 protocol = connect Only the connect protocol supports using the protocolHost option. If this isn't supported by your proxy, you can try using Privoxy or Polipo between stunnel and your proxy. Socat is another option as well. Andrew Krause Schaumburg Township District Library -----Original Message----- At QUT Library we use Stunnel to encrypt SIP2 (ie. book borrowing) traffic from the self-checkout machines through to the Alma library services platform (as per https://developers.exlibrisgroup.com/alma/integrations/stunnel/ ) Our self-checkout machines run Windows 10 and are allowed limited internet access to two hosts (cloud.fetechgroup.com and ap01.alma.exlibrisgroup.com) via our institution's Squid proxy and I have our current WinHTTP proxy settings: Proxy Server(s) : wproxy.qut.edu.au:3128 Bypass List : *.qut.edu.au The proxy server settings are set for all protocols (HTTP, HTTPS, secure and FTP) and I've confirmed that web browser and the FE Technologies software is routing via wproxy.qut.edu.au. However Stunnel is still trying to connect to Alma directly. Our stunnel.conf is as follows (just FYI, the FE Tech software points to 127.0.0.1:5001 as our library services platform address): [KG_Self-Checkout] key = client.pem cert = client.pem client = yes accept = 127.0.0.1:5001 connect = ap01.alma.exlibrisgroup.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 sslVersion = TLSv1.2 Is there a way to force Stunnel to either respect the WinHTTP settings or configure it to route traffic to wproxy.qut.edu.au:3128 before initiating the connect = hostname:port? I did try protocolHost as follows, but I'm probably misunderstanding how it works https://www.stunnel.org/static/stunnel.html#SERVICE-LEVEL-OPTIONS [KG_Self-Checkout] key = client.pem cert = client.pem client = yes accept = 127.0.0.1:5001 connect = wproxy.qut.edu.au:3128 protocolHost = ap01.alma.exlibrisgroup.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 sslVersion = TLSv1.2 Any advice or assistance gratefully accepted, and apologies if this is a silly question - I'm just a librarian trying to make this thing work. Thanks, Jai Parker | Information Access Librarian QUT Library | Division of Administrative Services QUT | Kelvin Grove | D Block, Level 1 | Victoria Park Rd Kelvin Grove QLD 4059 P: 07 3138 3381 | E: lib.infoaccess at qut.edu.au<mailto:lib.infoaccess at qut.edu.au> | www.qut.edu.au<http://www.qut.edu.au/> ABN: 83 791 724 622 | CRICOS No. 00213J

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Re: [stunnel-users] stunnel-users Digest, Vol 184, Issue 4
by Brent Kimberley 08 Nov '19

08 Nov '19

From: Mark Brookes <mark(a)loadbalancer.org> To: Francois Robinette <frobinette(a)hotmail.com> >> OpenSSL 1.1.0k x Stunnel interaction... See tag 5.56b1Thanks. Can't find the 5.56b1 tag. Is it on a fork?https://github.com/mtrojnar/stunnel/network/members BTW. I had difficulty linking stunnel-5.56 (static) with OpenSSL 1.1.1d (static) as well. >> The stunnel guys have worked tirelessly to get this resolved. Its an >> interaction of openssl 1.1.0k and Stunnel. I think essentially openssl >> is doing something strange. They came up with a fix and its currently>> in the https://www.stunnel.org/downloads/beta/stunnel-5.56b1.tar.gz >> beta. You should give it a try and see if its resolves your issue. On Thu, 7 Nov 2019 at 19:36, Francois Robinette <frobinette(a)hotmail.com> wrote: > > I've seen other having the same issue without resolution so far... > But we do have the same issue: > > stunnel[7886]: segfault at 21 ip 00007f70aa1efcea sp 00007f6fa7797978 error 6 in libpthread-2.12.so[7f70aa1e5000+17000] >

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Stunnel traffic fails to go via proxy set in winhttp (Windows 10)
by Library Information Access Team 06 Nov '19

06 Nov '19

At QUT Library we use Stunnel to encrypt SIP2 (ie. book borrowing) traffic from the self-checkout machines through to the Alma library services platform (as per https://developers.exlibrisgroup.com/alma/integrations/stunnel/ ) Our self-checkout machines run Windows 10 and are allowed limited internet access to two hosts (cloud.fetechgroup.com and ap01.alma.exlibrisgroup.com) via our institution's Squid proxy and I have our current WinHTTP proxy settings: Proxy Server(s) : wproxy.qut.edu.au:3128 Bypass List : *.qut.edu.au The proxy server settings are set for all protocols (HTTP, HTTPS, secure and FTP) and I've confirmed that web browser and the FE Technologies software is routing via wproxy.qut.edu.au. However Stunnel is still trying to connect to Alma directly. Our stunnel.conf is as follows (just FYI, the FE Tech software points to 127.0.0.1:5001 as our library services platform address): [KG_Self-Checkout] key = client.pem cert = client.pem client = yes accept = 127.0.0.1:5001 connect = ap01.alma.exlibrisgroup.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 sslVersion = TLSv1.2 Is there a way to force Stunnel to either respect the WinHTTP settings or configure it to route traffic to wproxy.qut.edu.au:3128 before initiating the connect = hostname:port? I did try protocolHost as follows, but I'm probably misunderstanding how it works https://www.stunnel.org/static/stunnel.html#SERVICE-LEVEL-OPTIONS [KG_Self-Checkout] key = client.pem cert = client.pem client = yes accept = 127.0.0.1:5001 connect = wproxy.qut.edu.au:3128 protocolHost = ap01.alma.exlibrisgroup.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 sslVersion = TLSv1.2 Any advice or assistance gratefully accepted, and apologies if this is a silly question - I'm just a librarian trying to make this thing work. Thanks, Jai Parker | Information Access Librarian QUT Library | Division of Administrative Services QUT | Kelvin Grove | D Block, Level 1 | Victoria Park Rd Kelvin Grove QLD 4059 P: 07 3138 3381 | E: lib.infoaccess(a)qut.edu.au<mailto:lib.infoaccess@qut.edu.au> | www.qut.edu.au<http://www.qut.edu.au/> ABN: 83 791 724 622 | CRICOS No. 00213J

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Re: [stunnel-users] Extensions when negotiating TLS
by Christopher Schultz 05 Nov '19

05 Nov '19

Tom, On 11/4/19 17:59, Tom (AST) Watson wrote: > Trying to make the applications want to talk http/1.1 isn't going to > be easy. Both sides (app#1 and app#2) want to talk http2 (*SIGH*). Understood. > I was just hoping stunnel might work. Presently it looks like it > won't so I am looking at alternatives. Part of the object is to look > at the various transactions over the wire (many!) and they are lots. > I assume that is why http2 is used, and I have no influence over > that decision. From the looks of it, making app#2 unencrypted is the > best path. Boo! > It is written in GO, and has little comments to describe things (such > is life!). I think I'm a bit closer to a solution, but if stunnel > can be made to work (ALPN support) it would be nice. Looks like I'll > have to wait. Why isn't it an option to enable encryption directly on the service? It seems like using stunnel should be your last resort. -chris > -----Original Message----- > From: stunnel-users <stunnel-users-bounces(a)stunnel.org> On Behalf Of Christopher Schultz > > Tom, > > On 11/4/19 17:16, Tom (AST) Watson wrote: >> Yes, I understand about ALPN. Sorry I described in detail. >> Unfortunately application #2 wants encrypted http2 (it is a go >> program). Application #1 wants to talk in http2 (I can't change >> that!) and it doesn't encrypt "naturally" (and I want to see what is >> going on [Wireshark] as well) In looking further I might be able to >> get application #2 to go plaintext (I found a pointer). Yes, it seems >> that stunnel doesn't support ALPN, wishful thinking on my part >> >> Back to the salt mines. (*SIGH*) > > How difficult would it be to enable HTTP/1.1 on that application #1? > I've never seen an h2-only service before. h2 is more effective for web applications that make a lot of tiny requests (like small resources for pages, scripts, etc.). Most API-based services don't really get any benefit from using h2. > > -chris > >> -----Original Message----- From: stunnel-users >> <stunnel-users-bounces(a)stunnel.org> On Behalf Of Christopher Schultz >> Sent: Monday, November 4, 2019 13:59 To: stunnel-users(a)stunnel.org >> Subject: [External] Re: [stunnel-users] Extensions when negotiating >> TLS >> >> Tom, >> >> On 11/4/19 16:05, Tom (AST) Watson wrote: >>> Well, I thought it would be "easy", but maybe not. I have an >>> application (#1) that uses http2, and isn't encrypted. No problem >>> here. Now I have another application (#2) that insists on using >>> https to talk to application #1. So I gleefully setup stunnel to >>> connect the two. Well, application #2 starts talking to stunnel with >>> a "Client Hello" packet, and it includes an extension "Application >>> Layer Protocol Extension" of "h2". >> >> This is called ALPN, and is a requirement for h2s. >> >>> While not versed in the minutia, I take this that the client >>> (application #2) wants to talk "http2" to the server (application >>> #1). >> >> Yep, pretty much. >> >>> OK, that is what I want. The problem is that stunnel doesn't respond >>> with ANY "Application Layer Protocol Extension" indicating acceptance >>> of this request in its "server hello". This means that application >>> #2 fails in its negotiation. No joy! >>> >>> Now I know that application #1 will nicely talk http2, but how do I >>> get stunnel to communicate this to application #2 (as encrypted >>> http2). Am I missing something in my (pretty simple) configuration >>> file? >> >> I can't find any references to stunnel supporting ALPN. You may be >> (temporarily) out of luck, at least with stunnel. >> >> You mentioned that app #2 insists on encryption (great, usually). Is >> there a requirement that it use h2? Or can it be configured to use >> HTTP/1.1? >> >> -chris >> >

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Re: [stunnel-users] Extensions when negotiating TLS
by Christopher Schultz 04 Nov '19

04 Nov '19

Tom, On 11/4/19 17:16, Tom (AST) Watson wrote: > Yes, I understand about ALPN. Sorry I described in detail. > Unfortunately application #2 wants encrypted http2 (it is a go > program). Application #1 wants to talk in http2 (I can't change > that!) and it doesn't encrypt "naturally" (and I want to see what is > going on [Wireshark] as well) In looking further I might be able to > get application #2 to go plaintext (I found a pointer). Yes, it seems > that stunnel doesn't support ALPN, wishful thinking on my part > > Back to the salt mines. (*SIGH*) How difficult would it be to enable HTTP/1.1 on that application #1? I've never seen an h2-only service before. h2 is more effective for web applications that make a lot of tiny requests (like small resources for pages, scripts, etc.). Most API-based services don't really get any benefit from using h2. -chris > -----Original Message----- From: stunnel-users > <stunnel-users-bounces(a)stunnel.org> On Behalf Of Christopher Schultz > Sent: Monday, November 4, 2019 13:59 To: stunnel-users(a)stunnel.org > Subject: [External] Re: [stunnel-users] Extensions when negotiating > TLS > > Tom, > > On 11/4/19 16:05, Tom (AST) Watson wrote: >> Well, I thought it would be "easy", but maybe not. I have an >> application (#1) that uses http2, and isn't encrypted. No problem >> here. Now I have another application (#2) that insists on using >> https to talk to application #1. So I gleefully setup stunnel to >> connect the two. Well, application #2 starts talking to stunnel >> with a "Client Hello" packet, and it includes an extension >> "Application Layer Protocol Extension" of "h2". > > This is called ALPN, and is a requirement for h2s. > >> While not versed in the minutia, I take this that the client >> (application #2) wants to talk "http2" to the server (application >> #1). > > Yep, pretty much. > >> OK, that is what I want. The problem is that stunnel doesn't >> respond with ANY "Application Layer Protocol Extension" indicating >> acceptance of this request in its "server hello". This means that >> application #2 fails in its negotiation. No joy! >> >> Now I know that application #1 will nicely talk http2, but how do I >> get stunnel to communicate this to application #2 (as encrypted >> http2). Am I missing something in my (pretty simple) configuration >> file? > > I can't find any references to stunnel supporting ALPN. You may be > (temporarily) out of luck, at least with stunnel. > > You mentioned that app #2 insists on encryption (great, usually). Is > there a requirement that it use h2? Or can it be configured to use > HTTP/1.1? > > -chris >

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Extensions when negotiating TLS
by Tom (AST) Watson 04 Nov '19

04 Nov '19

Well, I thought it would be "easy", but maybe not. I have an application (#1) that uses http2, and isn't encrypted. No problem here. Now I have another application (#2) that insists on using https to talk to application #1. So I gleefully setup stunnel to connect the two. Well, application #2 starts talking to stunnel with a "Client Hello" packet, and it includes an extension "Application Layer Protocol Extension" of "h2". While not versed in the minutia, I take this that the client (application #2) wants to talk "http2" to the server (application #1). OK, that is what I want. The problem is that stunnel doesn't respond with ANY "Application Layer Protocol Extension" indicating acceptance of this request in its "server hello". This means that application #2 fails in its negotiation. No joy! Now I know that application #1 will nicely talk http2, but how do I get stunnel to communicate this to application #2 (as encrypted http2). Am I missing something in my (pretty simple) configuration file? Thanks. -- Tom Watson (I'm at work now) Thomas.3.watson(a)raytheon.com

2 1

Debian 9 static build
by Chris Maciejewski 01 Nov '19

01 Nov '19

Hello, I am trying to build stunnel 5.55 on Debian 9 x64 statistically against latest OpenSSL build from source. The system already has openssl and libssl ver. 1.1.1b installed via apt-get , but I want to build against OpenSSL 1.1.1d instead. What I do is: 1. Build and install OpenSSL: $ cd /usr/src/openssl-1.1.1d $ ./config -fPIC --prefix=/opt/openssl $ make depend && make && make install 2. Build and install Stunnel $ cd /usr/src/stunnel-5.55 $ ./configure --with-ssl=/opt/openssl --enable-static $ make && make install Both 1 and 2 completes OK with no errors, however when I run: $ /usr/local/bin/stunnel [.] Compiled with OpenSSL 1.1.1d 10 Sep 2019 [.] Running with OpenSSL 1.1.1b 26 Feb 2019 .... and indeed when I do: $ ldd /usr/local/bin/stunnel libssl.so.1.1 => /usr/lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f1083b4f000) libcrypto.so.1.1 => /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f1083668000) above shows dynamic .so libs are used, rather than static libs libssl.a and libcrypto.a Any suggestions as to what is wrong with my process above and how to make static build of Stunnel to use non-system OpenSSL very much appreciated. Kind regards, Chris

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Re: [stunnel-users] stunnel-users Digest, Vol 183, Issue 4
by Brent Kimberley 26 Oct '19

26 Oct '19

Chris.Does this help? https://stackoverflow.com/questions/40454338/no-shared-cipher-at-ssl-accept… If you can rule out libraries like OpenSSL, then look at your config + initial setup exchange. Date: Fri, 25 Oct 2019 11:11:54 -0400 From: Christopher Schultz <chris(a)christopherschultz.net> Subject: Re: [stunnel-users] Strange connection failure in one environmentOn 10/25/19 10:09, Christopher Schultz wrote: > All, > > I've been using stunnel in two environments (dev, prod) for a long time > without any problems. Recently, my dev environment started acting funny > and I can't connect to it from outside the box. > > Can someone take a look and let me know if you have any suggestions for > where to look for a problem? > > Both environments have the following things in common: > > 1. Hosted in Amazon EC2, no load-balancer in the way > 2. Configuration requires client-certificate to connect > 3. All certificates are valid, self-signed, and properly-trusted by both > sides > 4. TLS configuration has been locked-down to TLSv1.2, selected cipher > suites, FIPS mode=off > 5. All versions are the same: stunnel 4.56 w/OpenSSL 1.0.2k-fips > > The production (working) environment happens to be i686 and the > development environment happens to be x86-86, but I don't believe that > is relevant. > > When I use e.g. "openssl s_client" to connect to the production > environment and I *do not* provide a client certificate, I am able to > perform the initial TLS handshake, get a cipher suite negotiated, etc. > and then the connection fails because I didn't provide the client > certificate, of course. I *can* see in the handshake the list of allowed > client certificates. > > When I do the same in development, I get a handshake failure. No allowed > client certificates are shown. No nothing. > > If I connect on localhost to the dev server, I get what I'm expecting: > allowed client certificates are listed, connection is closed because I'm > not using the client certificate. Connecting from another host gets my a > handshake failure. > > Again, there are no load-balancers or anything between the outside and > the EC2 instance. I'm connecting as directly as it's possible to > connect. The box definitely allows incoming connections on the port I'm > trying to use; the AWS security group is configured correctly. > > I have tried dropping ALL security configuration on the dev server's > stunnel.conf such as client-cert requirements, TLS protocols, cipher > suites, etc. and I get the same behavior every time. I'm starting to > think that it has nothing to do with my stunnel.conf configuration at > all, but I'm at a loss as to where to look, next. > > Any ideas? Some more information: 0. The error I get on the client is "handshake failure" and the stunnel server drops this log message: SSL_accept: 1408A0C1: error:1408A0C1:SSL routines:ssl3_get_client_hello:no shared cipher Note that I have disabled all but TLSv1.2 on the server. Removing this restriction does not change the behavior. 1. I have multiple stunnel configuration files on this server. Actually, I have 4 of them. Connections to ports defined in 2 of these files are not connecting successfully. Connections to ports defined in the OTHER two files *are* connecting successfully. The configurations seem to follow a pattern: those using RSA certificates as the server-certificate are working as expected, while those with EC server-certificate are failing. When I say "working" versus "failing", I mean that this command will give me a cipher suite and master key, but still drop the connection because I'm not providing a client-certificate for these tests: $ openssl s_client -connect host:port 2. I have a Java-based service that *is* able to connect through this stunnel instance just fine. It's running on a recent version of Java 8. My CLI client (not OpenSSL) is also running the same version. My CLI client cannot connect. *weird* In both cases, I am using EC client certificates, but the certificates are different from each other. Both of these certificates are trusted by the server. 3. When using OpenSSL 1.0.2t, I *can* connect, get the list of acceptable client certificates, etc. even without providing a client certificate. When using OpenSSL 1.1.1d, I can *not* connect. So perhaps the inside/outside networking thing I was thinking the problem might be is incorrect. AFAIK, both versions of OpenSSL should be able to use EC certificates and cipher suites. Thanks, -chris

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Strange connection failure in one environment
by Christopher Schultz 25 Oct '19

25 Oct '19

All, I've been using stunnel in two environments (dev, prod) for a long time without any problems. Recently, my dev environment started acting funny and I can't connect to it from outside the box. Can someone take a look and let me know if you have any suggestions for where to look for a problem? Both environments have the following things in common: 1. Hosted in Amazon EC2, no load-balancer in the way 2. Configuration requires client-certificate to connect 3. All certificates are valid, self-signed, and properly-trusted by both sides 4. TLS configuration has been locked-down to TLSv1.2, selected cipher suites, FIPS mode=off 5. All versions are the same: stunnel 4.56 w/OpenSSL 1.0.2k-fips The production (working) environment happens to be i686 and the development environment happens to be x86-86, but I don't believe that is relevant. When I use e.g. "openssl s_client" to connect to the production environment and I *do not* provide a client certificate, I am able to perform the initial TLS handshake, get a cipher suite negotiated, etc. and then the connection fails because I didn't provide the client certificate, of course. I *can* see in the handshake the list of allowed client certificates. When I do the same in development, I get a handshake failure. No allowed client certificates are shown. No nothing. If I connect on localhost to the dev server, I get what I'm expecting: allowed client certificates are listed, connection is closed because I'm not using the client certificate. Connecting from another host gets my a handshake failure. Again, there are no load-balancers or anything between the outside and the EC2 instance. I'm connecting as directly as it's possible to connect. The box definitely allows incoming connections on the port I'm trying to use; the AWS security group is configured correctly. I have tried dropping ALL security configuration on the dev server's stunnel.conf such as client-cert requirements, TLS protocols, cipher suites, etc. and I get the same behavior every time. I'm starting to think that it has nothing to do with my stunnel.conf configuration at all, but I'm at a loss as to where to look, next. Any ideas? -chris

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ssl offloading with stunnel
by simona vittori 23 Oct '19

23 Oct '19

Hello,Is it possible to have the following architecture with stunnel? stunnel client --> balancer --> db server Balancer doesn't have stunnel product installed on it. It receives encrypted packages from stunnel client and redirect clear traffico to DB server. Is it possible to realize this configuration? Thank a lot. Regards Simona

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stunnel : user identification in mutual auth
by Denis Polushin 22 Oct '19

22 Oct '19

Hi All, Haven't found the answer for this issue. The scheme is : TLS-client <==tls==> stunnel-server <==open==> App-server In user session stunnel-server perform authorization for client with its certificate (verify=2) and send request further to App-server. How does App-server can identify user in this session? To grand permissions. Ideally it would be good to know CN or EKU of user certificate. Is it possible? Thanks a lot!! Denis

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segfault with v5.55
by Mark Brookes 30 Sep '19

30 Sep '19

We are currently experiencing a segfault with version 5.55 openssl version 1.1.0k and are trying to narrow down what the issue may be. The first 2 segfaults are about 10 mins apart. The below is from the stunnel log just before and then after the event. Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77582]: TLS state (accept): SSLv3/TLS write finished Sep 23 11:47:31 xxxx stunnel: LOG7[77582]: TLS state (accept): SSLv3/TLS read change cipher spec Sep 23 11:47:31 xxxx stunnel: LOG7[77582]: TLS state (accept): SSLv3/TLS read finished Sep 23 11:47:31 xxxx stunnel: LOG7[77580]: TLS state (accept): SSLv3/TLS write finished Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Deallocating application specific data for session connect address Sep 23 11:47:31 xxxx stunnel: LOG7[77581]: Remove session callback Sep 23 11:52:58 xxxx stunnel: LOG7[ui]: Clients allowed=62937 Sep 23 11:52:58 xxxx stunnel: LOG5[ui]: stunnel 5.55 on x86_64-pc-linux-gnu platform Sep 23 11:52:58 xxxx stunnel: LOG5[ui]: Compiled/running with OpenSSL 1.1.0k 28 May 2019 Sep 23 11:52:58 xxxx stunnel: LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI Sep 23 11:52:58 xxxx stunnel: LOG7[ui]: errno: (*__errno_location ()) The following is from the kernel log. stunnel[31253]: segfault at 0 ip 00007f91214cacea sp 00007f91205ea9f8 error 6 in libpthread-2.12.so[7f91214c0000+17000] The kernel log after the second segfault- stunnel[1868]: segfault at 0 ip 00007f5b35398cea sp 00007f5b344c59f8 error 6 in libpthread-2.12.so[7f5b3538e000+17000] This is all the information we have at the moment. -- Mark Brookes Loadbalancer.org Ltd. www.loadbalancer.org +44 (0)330 380 1064 mark(a)loadbalancer.org

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Re: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections
by Lynch, Andrew 27 Sep '19

27 Sep '19

I’ve been digging around the code and I am no longer sure whether stunnel is at fault or it is actually an issue in OpenSSL! load_key_engine() in ctx.c shoves the key into the SSL context – SSL_CTX_use_PrivateKey(section->ctx, pkey). So the key should be freed when that context is disposed of. The SIGHUP ends up in case SIGNAL_RELOAD_CONFIG of signal_pipe_dispatch(), which calls options_free() [stunnel.c line 830]. Eventually there is an SSL_CTX_free() call, but it looks like this does not actually free the private key. Ephemeral keys are freed and loads of other stuff, but not the private key associated with the certificate. I may try to build a hacked OpenSSL on Monday to see what happens if SSL_CTX_free also frees the private key… Regards, Andrew. From: Brent Kimberley [mailto:brent_kimberley@rogers.com] Sent: Friday, September 27, 2019 4:29 PM To: stunnel-users(a)stunnel.org; Lynch, Andrew Subject: Re: stunnel-users Digest, Vol 182, Issue 14 >> Over time, after numerous reloads of stunnel (kill -HUP) the HSM reports that its connection table is full. >> Logging from the engine shows that stunnel is never freeing the keys and therefore the engine is not closing the associated sessions with the HSM. Each stunnel reload opens 70 new sessions until eventually the HSM's configured limit is exceeded. Where does the signal dispatcher free keys on SIG_HUP? https://github.com/mtrojnar/stunnel/blob/master/src/stunnel.c Date: Fri, 27 Sep 2019 07:23:29 +0000 From: "Lynch, Andrew" <andrew.lynch(a)atos.net<mailto:andrew.lynch@atos.net>> To: Eric Eberhard <flash(a)vicsmba.com<mailto:flash@vicsmba.com>> Cc: "stunnel-users(a)stunnel.org<mailto:stunnel-users@stunnel.org>" <stunnel-users(a)stunnel.org<mailto:stunnel-users@stunnel.org>> Subject: Re: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections Hi Eric, Thank you for your suggestion. It is certainly worth looking into, although I suspect it may be impractical in our environment. Now we have a single stunnel.conf with 70 services which would translate into 70 additional entries in inetd.conf. Each of those entries then needs to have its own reduced stunnel.conf so that it will only load the cert and key for its endpoint. The stunnel HOWTO recommends daemon mode over inetd mode due to the overhead for forking and SSL initialization. We would have additional overhead for engine init and HSM connection. Regards, Andrew. -----Original Message----- From: Eric Eberhard [mailto:flash@vicsmba.com<mailto:flash@vicsmba.com>] Sent: Thursday, September 26, 2019 7:20 PM To: Lynch, Andrew; stunnel-users(a)stunnel.org<mailto:stunnel-users@stunnel.org> Subject: RE: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections? Try running in inetd mode -- even if you don't like this you will learn something. Inetd will close connections as needed. E -----Original Message----- From: stunnel-users [mailto:stunnel-users-bounces@stunnel.org<mailto:stunnel-users-bounces@stunnel.org>] On Behalf Of Lynch, Andrew Sent: Thursday, September 26, 2019 5:56 AM To: stunnel-users(a)stunnel.org<mailto:stunnel-users@stunnel.org> Subject: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections? Hi, We are using stunnel as a server to terminate incoming TLS connections. The config has around 70 services with certificates whose EC private keys are stored in an HSM and accessed using an OpenSSL engine. Over time, after numerous reloads of stunnel (kill -HUP) the HSM reports that its connection table is full. Logging from the engine shows that stunnel is never freeing the keys and therefore the engine is not closing the associated sessions with the HSM. Each stunnel reload opens 70 new sessions until eventually the HSM's configured limit is exceeded. This behaviour has been observed on Suse Enterprise Linux 12.3 with the system-provided stunnel-5.00-4.3.4, but I can reproduce it with my own build of the current version 5.55. Is this a known issue? It appears that other (ephemeral) keys are being freed, just not those associated with the service certificates. Currently our workaround is to perform a full restart instead of a reload. This closes all HSM sessions when the process terminates, but of course it also kills any open client connections so it can only be done during the scheduled maintenance windows. Regards, Andrew. _______________________________________________ stunnel-users mailing list stunnel-users(a)stunnel.org<mailto:stunnel-users@stunnel.org> https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users ------------------------------ Subject: Digest Footer _______________________________________________ stunnel-users mailing list stunnel-users(a)stunnel.org<mailto:stunnel-users@stunnel.org> https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users ------------------------------ End of stunnel-users Digest, Vol 182, Issue 14 **********************************************

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Re: [stunnel-users] stunnel-users Digest, Vol 182, Issue 14
by Eric Eberhard 27 Sep '19

27 Sep '19

I don’t suggest it as a final solution – although for me it works great and we have customers exchanging 2-4 million XML documents per day with no performance issues – BUT no matter what it is a good debugging tool. Inetd gets all the initial connections and closes them when done. It might or might or might not be involved with the HSM at all. You might also look at the process table (some form of ps) and grep for stunnel and relatives and see if they are hanging around. In theory, if a process dies, it “should” close it’s connections. If it is floating in space it will not. Inetd will kill the process – at least on Centos and AIX and SCO – for sure and for certain. E From: stunnel-users [mailto:stunnel-users-bounces@stunnel.org] On Behalf Of Brent Kimberley Sent: Friday, September 27, 2019 7:29 AM To: stunnel-users(a)stunnel.org; andrew.lynch(a)atos.net Subject: Re: [stunnel-users] stunnel-users Digest, Vol 182, Issue 14 >> Over time, after numerous reloads of stunnel (kill -HUP) the HSM reports that its connection table is full. >> Logging from the engine shows that stunnel is never freeing the keys and therefore the engine is not closing the associated sessions with the HSM. Each stunnel reload opens 70 new sessions until eventually the HSM's configured limit is exceeded. Where does the signal dispatcher free keys on SIG_HUP? https://github.com/mtrojnar/stunnel/blob/master/src/stunnel.c Date: Fri, 27 Sep 2019 07:23:29 +0000 From: "Lynch, Andrew" <andrew.lynch(a)atos.net <mailto:andrew.lynch@atos.net> > To: Eric Eberhard <flash(a)vicsmba.com <mailto:flash@vicsmba.com> > Cc: "stunnel-users(a)stunnel.org <mailto:stunnel-users@stunnel.org> " <stunnel-users(a)stunnel.org <mailto:stunnel-users@stunnel.org> > Subject: Re: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections Hi Eric, Thank you for your suggestion. It is certainly worth looking into, although I suspect it may be impractical in our environment. Now we have a single stunnel.conf with 70 services which would translate into 70 additional entries in inetd.conf. Each of those entries then needs to have its own reduced stunnel.conf so that it will only load the cert and key for its endpoint. The stunnel HOWTO recommends daemon mode over inetd mode due to the overhead for forking and SSL initialization. We would have additional overhead for engine init and HSM connection. Regards, Andrew. -----Original Message----- From: Eric Eberhard [mailto:flash@vicsmba.com <mailto:flash@vicsmba.com> ] Sent: Thursday, September 26, 2019 7:20 PM To: Lynch, Andrew; stunnel-users(a)stunnel.org <mailto:stunnel-users@stunnel.org> Subject: RE: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections? Try running in inetd mode -- even if you don't like this you will learn something. Inetd will close connections as needed. E -----Original Message----- From: stunnel-users [mailto:stunnel-users-bounces@stunnel.org <mailto:stunnel-users-bounces@stunnel.org> ] On Behalf Of Lynch, Andrew Sent: Thursday, September 26, 2019 5:56 AM To: stunnel-users(a)stunnel.org <mailto:stunnel-users@stunnel.org> Subject: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections? Hi, We are using stunnel as a server to terminate incoming TLS connections. The config has around 70 services with certificates whose EC private keys are stored in an HSM and accessed using an OpenSSL engine. Over time, after numerous reloads of stunnel (kill -HUP) the HSM reports that its connection table is full. Logging from the engine shows that stunnel is never freeing the keys and therefore the engine is not closing the associated sessions with the HSM. Each stunnel reload opens 70 new sessions until eventually the HSM's configured limit is exceeded. This behaviour has been observed on Suse Enterprise Linux 12.3 with the system-provided stunnel-5.00-4.3.4, but I can reproduce it with my own build of the current version 5.55. Is this a known issue? It appears that other (ephemeral) keys are being freed, just not those associated with the service certificates. Currently our workaround is to perform a full restart instead of a reload. This closes all HSM sessions when the process terminates, but of course it also kills any open client connections so it can only be done during the scheduled maintenance windows. Regards, Andrew. _______________________________________________ stunnel-users mailing list stunnel-users(a)stunnel.org <mailto:stunnel-users@stunnel.org> https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users ------------------------------ Subject: Digest Footer _______________________________________________ stunnel-users mailing list stunnel-users(a)stunnel.org <mailto:stunnel-users@stunnel.org> https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users ------------------------------ End of stunnel-users Digest, Vol 182, Issue 14 **********************************************

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Re: [stunnel-users] stunnel-users Digest, Vol 182, Issue 14
by Brent Kimberley 27 Sep '19

27 Sep '19

>> Over time, after numerous reloads of stunnel (kill -HUP) the HSM reports that its connection table is full. >> Logging from the engine shows that stunnel is never freeing the keys and therefore the engine is not closing the associated sessions with the HSM. Each stunnel reload opens 70 new sessions until eventually the HSM's configured limit is exceeded. Where does the signal dispatcher free keys on SIG_HUP?https://github.com/mtrojnar/stunnel/blob/master/src/stunnel.c Date: Fri, 27 Sep 2019 07:23:29 +0000 From: "Lynch, Andrew" <andrew.lynch(a)atos.net> To: Eric Eberhard <flash(a)vicsmba.com> Cc: "stunnel-users(a)stunnel.org" <stunnel-users(a)stunnel.org> Subject: Re: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections Hi Eric, Thank you for your suggestion. It is certainly worth looking into, although I suspect it may be impractical in our environment. Now we have a single stunnel.conf with 70 services which would translate into 70 additional entries in inetd.conf. Each of those entries then needs to have its own reduced stunnel.conf so that it will only load the cert and key for its endpoint. The stunnel HOWTO recommends daemon mode over inetd mode due to the overhead for forking and SSL initialization. We would have additional overhead for engine init and HSM connection. Regards, Andrew. -----Original Message----- From: Eric Eberhard [mailto:flash@vicsmba.com] Sent: Thursday, September 26, 2019 7:20 PM To: Lynch, Andrew; stunnel-users(a)stunnel.org Subject: RE: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections? Try running in inetd mode -- even if you don't like this you will learn something. Inetd will close connections as needed. E -----Original Message----- From: stunnel-users [mailto:stunnel-users-bounces@stunnel.org] On Behalf Of Lynch, Andrew Sent: Thursday, September 26, 2019 5:56 AM To: stunnel-users(a)stunnel.org Subject: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections? Hi, We are using stunnel as a server to terminate incoming TLS connections. The config has around 70 services with certificates whose EC private keys are stored in an HSM and accessed using an OpenSSL engine. Over time, after numerous reloads of stunnel (kill -HUP) the HSM reports that its connection table is full. Logging from the engine shows that stunnel is never freeing the keys and therefore the engine is not closing the associated sessions with the HSM. Each stunnel reload opens 70 new sessions until eventually the HSM's configured limit is exceeded. This behaviour has been observed on Suse Enterprise Linux 12.3 with the system-provided stunnel-5.00-4.3.4, but I can reproduce it with my own build of the current version 5.55. Is this a known issue? It appears that other (ephemeral) keys are being freed, just not those associated with the service certificates. Currently our workaround is to perform a full restart instead of a reload. This closes all HSM sessions when the process terminates, but of course it also kills any open client connections so it can only be done during the scheduled maintenance windows. Regards, Andrew. _______________________________________________ stunnel-users mailing list stunnel-users(a)stunnel.org https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users ------------------------------ Subject: Digest Footer _______________________________________________ stunnel-users mailing list stunnel-users(a)stunnel.org https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users ------------------------------ End of stunnel-users Digest, Vol 182, Issue 14 **********************************************

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Re: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections?
by Eric Eberhard 27 Sep '19

27 Sep '19

Try running in inetd mode -- even if you don't like this you will learn something. Inetd will close connections as needed. E -----Original Message----- From: stunnel-users [mailto:stunnel-users-bounces@stunnel.org] On Behalf Of Lynch, Andrew Sent: Thursday, September 26, 2019 5:56 AM To: stunnel-users(a)stunnel.org Subject: [stunnel-users] stunnel with OpenSSL engine: reload leaks HSM connections? Hi, We are using stunnel as a server to terminate incoming TLS connections. The config has around 70 services with certificates whose EC private keys are stored in an HSM and accessed using an OpenSSL engine. Over time, after numerous reloads of stunnel (kill -HUP) the HSM reports that its connection table is full. Logging from the engine shows that stunnel is never freeing the keys and therefore the engine is not closing the associated sessions with the HSM. Each stunnel reload opens 70 new sessions until eventually the HSM's configured limit is exceeded. This behaviour has been observed on Suse Enterprise Linux 12.3 with the system-provided stunnel-5.00-4.3.4, but I can reproduce it with my own build of the current version 5.55. Is this a known issue? It appears that other (ephemeral) keys are being freed, just not those associated with the service certificates. Currently our workaround is to perform a full restart instead of a reload. This closes all HSM sessions when the process terminates, but of course it also kills any open client connections so it can only be done during the scheduled maintenance windows. Regards, Andrew. _______________________________________________ stunnel-users mailing list stunnel-users(a)stunnel.org https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users

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stunnel with OpenSSL engine: reload leaks HSM connections?
by Lynch, Andrew 26 Sep '19

26 Sep '19

Hi, We are using stunnel as a server to terminate incoming TLS connections. The config has around 70 services with certificates whose EC private keys are stored in an HSM and accessed using an OpenSSL engine. Over time, after numerous reloads of stunnel (kill -HUP) the HSM reports that its connection table is full. Logging from the engine shows that stunnel is never freeing the keys and therefore the engine is not closing the associated sessions with the HSM. Each stunnel reload opens 70 new sessions until eventually the HSM's configured limit is exceeded. This behaviour has been observed on Suse Enterprise Linux 12.3 with the system-provided stunnel-5.00-4.3.4, but I can reproduce it with my own build of the current version 5.55. Is this a known issue? It appears that other (ephemeral) keys are being freed, just not those associated with the service certificates. Currently our workaround is to perform a full restart instead of a reload. This closes all HSM sessions when the process terminates, but of course it also kills any open client connections so it can only be done during the scheduled maintenance windows. Regards, Andrew.

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Re: [stunnel-users] Problems when using PSK between a version of stunnel usingopenssl 1.0 and a version of stunnel using openssl 1.1.1 in stunnel-users Digest, Vol 182, Issue 7
by Koperberg, J. (Hannah) 25 Sep '19

25 Sep '19

Hi Brent Thank you for your suggestions. I installed stunnel version 5.55 on the client test side (where the openssl version OpenSSL 1.1.1c is). That has solved the problem. Kind regards and thanks again for your help, Hannah Koperberg, de Volksbank N.V., The Netherlands From: Brent Kimberley <brent_kimberley(a)rogers.com> Sent: woensdag 18 september 2019 18:30 To: stunnel-users(a)stunnel.org Subject: Re: [stunnel-users] stunnel-users Digest, Vol 182, Issue 7 psk_find() and psk_server_callback() are marked NOEXPORT. You can try whitebox - decompile ctx.c:: psk_server_callback() and/or blackbox - breaking the problem into parts to see what works/fails. Decomposing the problem into parts : a) Two differing stunnel versions and a common openssl library. b) One common stunnel version and two differing openssl libraries. On Wednesday, September 18, 2019, 11:28:48 a.m. EDT, Brent Kimberley <brent_kimberley(a)rogers.com<mailto:brent_kimberley@rogers.com>> wrote: >> 2019.09.16 13:36:28 LOG6[3]: PSK identity not found (session resumption?) Try dumping the symbols for ctx.c::psk_find(), ssl_lib.c::SSL_get_ex_data(), and ctx.c:: psk_server_callback(). ________________________________ Dit e-mailbericht is alleen bestemd voor de geadresseerden. Indien dit bericht niet voor u is bedoeld, wordt u verzocht de afzender hiervan op de hoogte te stellen door het bericht te retourneren en de inhoud niet te gebruiken. This e-mail message is intended to be exclusively for the addressee. If you are not the intended recipient you are kindly requested not to make any use whatsoever of the contents and to notify the sender immediately by returning this e-mail message.

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Re: [stunnel-users] stunnel-users Digest, Vol 182, Issue 11
by Brent Kimberley 24 Sep '19

24 Sep '19

>>We are running stunnel-5.49-1.ppc on AIX 7100-05-03-1846. >>It will stay up awhile and our connection tests work, but it core dumps. Here’s the message in the log file. Thoughts? >>INTERNAL ERROR: Out of memory at s3_both.c, line 626 Hi Gerald. You may have found a memory leak. Try looking at: 1) line 626 of OpenSSL::s3_booth.c https://github.com/openssl/openssl/blob/OpenSSL_1_0_2-stable/ssl/s3_both.c 2) line 296 of stunnel::str.c ; and/or https://github.com/mtrojnar/stunnel/blob/stunnel-5.49/src/str.c 3) dbx, truss, or probevue - in an offline dev environment. http://archive.ibmsystemsmag.com/aix/administrator/performance/debugging-me…

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AIX:stunnel core dumping
by Gerald Shaw 24 Sep '19

24 Sep '19

Hello, We are running stunnel-5.49-1.ppc on AIX 7100-05-03-1846. It will stay up awhile and our connection tests work, but it core dumps. Here’s the message in the log file. Thoughts? INTERNAL ERROR: Out of memory at s3_both.c, line 626 Best, Gerald Shaw

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