Fix race condition when logging keystmp-keylog-threadsafe

Moves keylog initialization to _gnutls_global_init().
That means SSLKEYLOGFILE has to be set before starting the
application - or more exactly - before library initialization.

Signed-off-by: Tim Rühsen <tim.ruehsen@gmx.de>

6 files changed, 47 insertions, 26 deletions

diff --git a/lib/global.c b/lib/global.c
index 334148342e..2db225360e 100644
--- a/lib/global.c
+++ b/lib/global.c
@@ -369,6 +369,7 @@ static int _gnutls_global_init(unsigned constructor)
 	_gnutls_register_accel_crypto();
 	_gnutls_cryptodev_init();
 	_gnutls_load_system_priorities();
+	_gnutls_nss_keylog_init();
 
 #ifdef ENABLE_FIPS140
 	/* These self tests are performed on the overridden algorithms
diff --git a/lib/global.h b/lib/global.h
index d9a09d8cdd..63133c49a8 100644
--- a/lib/global.h
+++ b/lib/global.h
@@ -44,6 +44,7 @@ extern int _gnutls_log_level;
 extern int gnutls_crypto_init(void);
 extern void gnutls_crypto_deinit(void);
 extern void _gnutls_tpm_global_deinit(void);
+extern void _gnutls_nss_keylog_init(void);
 extern void _gnutls_nss_keylog_deinit(void);
 
 extern void _gnutls_load_system_priorities(void);
diff --git a/lib/kx.c b/lib/kx.c
index 69374908e4..875a56b71c 100644
--- a/lib/kx.c
+++ b/lib/kx.c
@@ -74,16 +74,6 @@ void _gnutls_nss_keylog_write(gnutls_session_t session,
 			      const char *label,
 			      const uint8_t *secret, size_t secret_size)
 {
-	static const char *keylogfile = NULL;
-	static unsigned checked_env = 0;
-
-	if (!checked_env) {
-		checked_env = 1;
-		keylogfile = secure_getenv("SSLKEYLOGFILE");
-		if (keylogfile != NULL)
-			keylog = fopen(keylogfile, "a");
-	}
-
 	if (keylog) {
 		char client_random_hex[2*GNUTLS_RANDOM_SIZE+1];
 		char secret_hex[2*MAX_HASH_SIZE+1];
@@ -102,6 +92,14 @@ void _gnutls_nss_keylog_write(gnutls_session_t session,
 	}
 }
 
+void _gnutls_nss_keylog_init(void)
+{
+	const char *keylogfile = secure_getenv("SSLKEYLOGFILE");
+
+	if (keylogfile)
+		keylog = fopen(keylogfile, "a");
+}
+
 void _gnutls_nss_keylog_deinit(void)
 {
 	if (keylog) {
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 34e3c5a970..efef919e38 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -105,7 +105,7 @@ noinst_LTLIBRARIES = libutils.la
 libutils_la_SOURCES = utils.h utils.c seccomp.c utils-adv.c
 libutils_la_LIBADD = ../lib/libgnutls.la
 
-indirect_tests = tls13/prf-early system-override-hash system-override-sig
+indirect_tests = tls13/prf-early system-override-hash system-override-sig keylog-env
 
 ctests = tls13/supported_versions tls13/tls12-no-tls13-exts \
 	tls13/post-handshake-with-cert tls13/post-handshake-without-cert \
@@ -191,7 +191,7 @@ ctests += mini-record-2 simple gnutls_hmac_fast set_pkcs12_cred cert certuniquei
 	 set_x509_key_file_der set_x509_pkcs12_key crt_apis tls12-cert-key-exchange \
 	 tls11-cert-key-exchange tls10-cert-key-exchange ssl30-cert-key-exchange \
 	 dtls12-cert-key-exchange dtls10-cert-key-exchange x509-cert-callback-legacy \
-	 keylog-env ssl2-hello tlsfeature-ext dtls-rehandshake-cert-2 dtls-session-ticket-lost \
+	 ssl2-hello tlsfeature-ext dtls-rehandshake-cert-2 dtls-session-ticket-lost \
 	 tlsfeature-crt dtls-rehandshake-cert-3 resume-with-false-start \
 	 set_x509_key_file_ocsp client-fastopen rng-sigint srp rng-pthread \
 	 safe-renegotiation/srn0 safe-renegotiation/srn1 safe-renegotiation/srn2 \
@@ -492,7 +492,7 @@ dist_check_SCRIPTS += fastopen.sh pkgconfig.sh starttls.sh starttls-ftp.sh start
 	ocsp-tests/ocsp-test cipher-listings.sh sni-hostname.sh server-multi-keys.sh \
 	psktool.sh ocsp-tests/ocsp-load-chain gnutls-cli-save-data.sh gnutls-cli-debug.sh \
 	sni-resume.sh ocsp-tests/ocsptool cert-reencoding.sh pkcs7-cat.sh long-crl.sh \
-	serv-udp.sh logfile-option.sh gnutls-cli-resume.sh profile-tests.sh
+	serv-udp.sh logfile-option.sh gnutls-cli-resume.sh profile-tests.sh keylog-env.sh
 
 if !DISABLE_SYSTEM_CONFIG
 dist_check_SCRIPTS += system-override-sig-hash.sh system-override-versions.sh system-override-invalid.sh \
diff --git a/tests/keylog-env.c b/tests/keylog-env.c
index 5f5f74e176..bdc079f868 100644
--- a/tests/keylog-env.c
+++ b/tests/keylog-env.c
@@ -98,16 +98,6 @@ static void run(const char *filename, const char *prio,
 	const char **p;
 	int ret;
 
-#ifdef _WIN32
-	{
-		char buf[512];
-		snprintf(buf, sizeof(buf), "SSLKEYLOGFILE=%s", filename);
-		_putenv(buf);
-	}
-#else
-	setenv("SSLKEYLOGFILE", filename, 1);
-#endif
-
 	if (debug) {
 		gnutls_global_set_log_level(6);
 		gnutls_global_set_log_function(tls_log_func);
@@ -151,11 +141,10 @@ static void run(const char *filename, const char *prio,
 
 void doit(void)
 {
-	char filename[TMPNAME_SIZE];
+	const char *filename = getenv("SSLKEYLOGFILE");
 
-	assert(get_tmpname(filename)!=NULL);
+	assert(filename != NULL);
 
-	remove(filename);
 	global_init();
 
 	run(filename,
diff --git a/tests/keylog-env.sh b/tests/keylog-env.sh
new file mode 100755
index 0000000000..6290877d5b
--- /dev/null
+++ b/tests/keylog-env.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+
+# Copyright (C) 2019 Tim Ruehsen
+#
+# Author: Tim Ruehsen
+#
+# This file is part of GnuTLS.
+#
+# GnuTLS is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 3 of the License, or (at
+# your option) any later version.
+#
+# GnuTLS is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GnuTLS; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+TMPFILE=c.$$.tmp
+
+export SSLKEYLOGFILE="${TMPFILE}"
+
+${builddir}/keylog-env
+if test $? != 0; then
+	exit 1
+fi
+
+exit 0