From 15e38be2f5208a0177f88722dab69a62de5fa52f Mon Sep 17 00:00:00 2001
From: Gerhard Rieger <gerhard@dest-unreach.org>
Date: Sat, 9 Jul 2022 15:29:26 +0200
Subject: [PATCH] Fixed SIGSEGV of OpenSSL on exit()

---
 CHANGES       | 8 ++++++++
 sslcls.c      | 6 +++---
 sslcls.h      | 2 +-
 xio-openssl.c | 8 ++++++--
 4 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/CHANGES b/CHANGES
index 787a424..e431fd4 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,12 @@
 
+Porting:
+	OpenSSL, at least 1.1 on Ubuntu, crashed with SIGSEGV under certain
+	conditions: client connection to server with certificate with empty
+	subject, and pressing ^C after successful connect.
+	This crash is now prevented by setting OPENSSL_INIT_NO_ATEXIT.
+	Thanks to Martin Dorey for reporting and analyzing this issue, and for
+	providing an environment for reproduction.
+
 Testing:
 	Unset SOCAT_MAIN_WAIT on informational Socat calls
 
diff --git a/sslcls.c b/sslcls.c
index a05e382..ce8e9c6 100644
--- a/sslcls.c
+++ b/sslcls.c
@@ -21,7 +21,7 @@
 #include "sysutils.h"
 #include "sycls.h"
 
-#if HAVE_OPENSSL_init_ssl
+#if HAVE_OPENSSL_INIT_SSL
 int sycOPENSSL_init_ssl(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings) {
    int result;
    Debug2("OPENSSL_init_ssl("F_uint64_t", %p)", opts, settings);
@@ -31,7 +31,7 @@ int sycOPENSSL_init_ssl(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings) {
 }
 #endif
 
-#if !HAVE_OPENSSL_init_ssl
+#if !HAVE_OPENSSL_INIT_SSL
 void sycSSL_load_error_strings(void) {
    Debug("SSL_load_error_strings()");
    SSL_load_error_strings();
@@ -39,7 +39,7 @@ void sycSSL_load_error_strings(void) {
 }
 #endif
 
-#if !HAVE_OPENSSL_init_ssl
+#if !HAVE_OPENSSL_INIT_SSL
 int sycSSL_library_init(void) {
    int result;
    Debug("SSL_library_init()");
diff --git a/sslcls.h b/sslcls.h
index df1c368..1412f80 100644
--- a/sslcls.h
+++ b/sslcls.h
@@ -8,7 +8,7 @@
 #if WITH_SYCLS
 #if WITH_OPENSSL
 
-#if HAVE_OPENSSL_init_ssl
+#if HAVE_OPENSSL_INIT_SSL
 int sycOPENSSL_init_ssl(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings);
 #endif
 void sycSSL_load_error_strings(void);
diff --git a/xio-openssl.c b/xio-openssl.c
index 58e7884..48fffa2 100644
--- a/xio-openssl.c
+++ b/xio-openssl.c
@@ -959,11 +959,15 @@ int
    openssl_delete_cert_info();
 
    /* OpenSSL preparation */
-#if HAVE_OPENSSL_init_ssl
+#if HAVE_OPENSSL_INIT_SSL
    {
+      uint64_t opts = 0;
       OPENSSL_INIT_SETTINGS *settings;
       settings = OPENSSL_INIT_new();
-      sycOPENSSL_init_ssl(0, settings);
+#ifdef OPENSSL_INIT_NO_ATEXIT
+      opts |= OPENSSL_INIT_NO_ATEXIT;
+#endif
+      sycOPENSSL_init_ssl(opts, settings);
    }
 #else
    sycSSL_library_init();