Bug 1870279

Summary: Transfer via socat fails with openssl enabled
Product: Red Hat Enterprise Linux 8 Reporter: Pavel Safronov <svp>
Component: socatAssignee: Ondrej Moriš <omoris>
Status: CLOSED ERRATA QA Contact: BaseOS QE Security Team <qe-baseos-security>
Severity: low Docs Contact:
Priority: low    
Version: CentOS StreamCC: bstinson, carl, davide, jwboyer, omoris
Target Milestone: rcKeywords: Rebase, Triaged, Upstream
Target Release: 8.0   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: socat-1.7.4.1-1.el8 Doc Type: No Doc Update
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2021-11-09 17:48:19 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
don't disable SSL_MODE_AUTO_RETRY none

Description Pavel Safronov 2020-08-19 16:08:07 UTC 
Description of problem:

The receiver side of the transfer with ssl enabled always hits "SSL_read(): Connection reset by peer" when it gets close to EOF and leaves the transfer partially finished.

Version-Release number of selected component (if applicable):
1.7.3.3-2.el8


How reproducible:
Almost always. 90% of my attempts failed


Steps to Reproduce:
1. Run the server `socat openssl-listen:12345,reuseaddr,pf=ip6,cert=server.pem - > /dev/null`
2. Run client `yes | head -n 1000000 | socat  -u - openssl-connect:[::1]:12345,cn=host:/example.com,cert=server.pem,cafile=ca.pem` (on the same machine or somewhere else, doesn't matter)
3. You should see an error like this on the receiving side as a result
2020/08/19 08:52:06 socat[2164968] E SSL_read(): Connection reset by peer


Actual results:
Getting an error "E SSL_read(): Connection reset by peer" and transfer fails


Expected results:
No error, transfer succeeds

Additional info:
Allegedly this is the consequence of the modification of file xio-openssl.c introduced in version 1.7.3.3 which forcefully disables SSL_MODE_AUTO_RETRY. After commenting out line "SSL_CTX_clear_mode(*ctx, SSL_MODE_AUTO_RETRY);" and rebuilding the client socat binary I don't have an error anymore.
Also it works well with version 1.7.3.2 of socat.
Comment 1 Pavel Safronov 2020-08-21 17:58:36 UTC 
This patch below is fixing the problem by rolling back the change. So basically we don't disable SSL_MODE_AUTO_RETRY anymore.

Tests run results:

For both tests I run the following command multiple times and check the server output
yes | head -n 1000000 | socat  -u - openssl-connect:[::1]:12345,cn=host:/example.com,cert=server.pem,cafile=ca.pem


With patch:
# while true; do socat openssl-listen:12345,reuseaddr,pf=ip6,cert=server.pem - > /dev/null; date; done
Fri Aug 21 10:53:11 PDT 2020
Fri Aug 21 10:53:13 PDT 2020
Fri Aug 21 10:53:15 PDT 2020
Fri Aug 21 10:53:17 PDT 2020
Fri Aug 21 10:53:19 PDT 2020
Fri Aug 21 10:53:22 PDT 2020
Fri Aug 21 10:53:24 PDT 2020

Without patch:
# while true; do ./socat openssl-listen:12345,reuseaddr,pf=ip6,cert=server.pem - > /dev/null; date; done
Fri Aug 21 10:50:01 PDT 2020
2020/08/21 10:50:02 socat[976825] E SSL_read(): Connection reset by peer
Fri Aug 21 10:50:02 PDT 2020
2020/08/21 10:50:05 socat[977067] E SSL_read(): Connection reset by peer
Fri Aug 21 10:50:05 PDT 2020
2020/08/21 10:50:07 socat[977300] E SSL_read(): Connection reset by peer
Fri Aug 21 10:50:07 PDT 2020
2020/08/21 10:50:09 socat[977442] E SSL_read(): Connection reset by peer
Fri Aug 21 10:50:09 PDT 2020
2020/08/21 10:50:10 socat[977660] E SSL_read(): Connection reset by peer
Fri Aug 21 10:50:10 PDT 2020
2020/08/21 10:50:12 socat[977718] E SSL_read(): Connection reset by peer
Fri Aug 21 10:50:12 PDT 2020
Fri Aug 21 10:50:14 PDT 2020



Here is the patch:

diff -Naur socat-1.7.3.3-orig/CHANGES socat-1.7.3.3/CHANGES
--- socat-1.7.3.3-orig/CHANGES	2019-04-05 13:10:24.000000000 -0700
+++ socat-1.7.3.3/CHANGES	2020-08-21 09:59:35.233714747 -0700
@@ -79,9 +79,6 @@
 	RES_AAONLY, RES_PRIMARY are deprecated. You can still enable them with
 	configure option --enable-res-deprecated.
 
-	New versions of OpenSSL preset SSL_MODE_AUTO_RETRY which may hang socat.
-	Solution: clear SSL_MODE_AUTO_RETRY when it is set.
-
 	Renamed configure.in to configure.ac and set an appropriate symlink for
 	older environments.
 	Related Gentoo bug 426262: Warning on configure.in
diff -Naur socat-1.7.3.3-orig/xio-openssl.c socat-1.7.3.3/xio-openssl.c
--- socat-1.7.3.3-orig/xio-openssl.c	2019-04-04 01:59:55.000000000 -0700
+++ socat-1.7.3.3/xio-openssl.c	2020-08-21 09:58:27.445138134 -0700
@@ -1023,18 +1023,6 @@
    }
 #endif
 
-   /* It seems that OpenSSL-1.1.1 presets the mode differently.
-      Without correction socat might hang in SSL_read() */
-   {
-      long mode = 0;
-      mode = SSL_CTX_get_mode(*ctx);
-      if (mode & SSL_MODE_AUTO_RETRY) {
-	 Info("SSL_CTX mode has SSL_MODE_AUTO_RETRY set. Correcting..");
-	 Debug1("SSL_CTX_clean_mode(%p, SSL_MODE_AUTO_RETRY)", *ctx);
-	 SSL_CTX_clear_mode(*ctx, SSL_MODE_AUTO_RETRY);
-      }
-   }
-
    if (opt_cafile != NULL || opt_capath != NULL) {
       if (sycSSL_CTX_load_verify_locations(*ctx, opt_cafile, opt_capath) != 1) {
 	 int result;
Comment 2 Pavel Safronov 2020-08-21 18:07:20 UTC 
Created a pull request to centos8 socat repo with the patch https://git.centos.org/rpms/socat/pull-request/1
Comment 3 Carl George 🤠 2020-08-24 16:36:47 UTC 
Created attachment 1712396 [details]
don't disable SSL_MODE_AUTO_RETRY

Here is the patch file from Pavel's pull request.  It is a revert of this upstream commit.

https://repo.or.cz/socat.git/commitdiff/bc3723e970bf5e47d681f719f67899046554459c?hp=7a621dd3a245a46c65b726b86a72564f84dced74
Comment 17 errata-xmlrpc 2021-11-09 17:48:19 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (socat bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2021:4167