Check for OpenSSL defines before trying to use them.

The SSL_OP_NO_TLSv1_1 and SSL_OP_NO_TLSv1_2 defines did not exist prior
to OpenSSL version 1.0.1. A recent commit attempts to, by default, set
these options, which can cause problems on systems with older OpenSSL
installations.

This commit adds a configure script check for those defines and will not
attempt to make use of those if they do not exist. We will print a
warning urging the user to upgrade their OpenSSL installation if those
defines are not present.

Change-Id: I6a2eb9a43fd0738b404d8f6f2cf4b5c22d9d752d

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.ac Revision: 425965 .
+# From configure.ac Revision.
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.69 for asterisk trunk.
 #
@@ -651,6 +651,8 @@ PBX_MSG_NOSIGNAL
 PBX_IXJUSER
 GMIME_LIBS
 GMIME_CFLAGS
+PBX_SSL_OP_NO_TLSV1_2
+PBX_SSL_OP_NO_TLSV1_1
 OPENH323_BUILD
 OPENH323_SUFFIX
 OPENH323_LIBDIR
@@ -29850,6 +29852,102 @@ _ACEOF
 fi
 
 
+fi
+
+if test "$PBX_OPENSSL" = "1";
+then
+
+    if test "x${PBX_SSL_OP_NO_TLSV1_1}" != "x1"; then
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for SSL_OP_NO_TLSv1_1 in openssl/ssl.h" >&5
+$as_echo_n "checking for SSL_OP_NO_TLSv1_1 in openssl/ssl.h... " >&6; }
+	saved_cppflags="${CPPFLAGS}"
+	if test "x${SSL_OP_NO_TLSV1_1_DIR}" != "x"; then
+	    SSL_OP_NO_TLSV1_1_INCLUDE="-I${SSL_OP_NO_TLSV1_1_DIR}/include"
+	fi
+	CPPFLAGS="${CPPFLAGS} ${SSL_OP_NO_TLSV1_1_INCLUDE}"
+
+	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+ #include <openssl/ssl.h>
+int
+main ()
+{
+#if defined(SSL_OP_NO_TLSv1_1)
+				int foo = 0;
+			        #else
+			        int foo = bar;
+			        #endif
+				0
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+     { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+		PBX_SSL_OP_NO_TLSV1_1=1
+
+$as_echo "#define HAVE_SSL_OP_NO_TLSV1_1 1" >>confdefs.h
+
+
+
+else
+     { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	CPPFLAGS="${saved_cppflags}"
+    fi
+
+
+
+    if test "x${PBX_SSL_OP_NO_TLSV1_2}" != "x1"; then
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for SSL_OP_NO_TLSv1_2 in openssl/ssl.h" >&5
+$as_echo_n "checking for SSL_OP_NO_TLSv1_2 in openssl/ssl.h... " >&6; }
+	saved_cppflags="${CPPFLAGS}"
+	if test "x${SSL_OP_NO_TLSV1_2_DIR}" != "x"; then
+	    SSL_OP_NO_TLSV1_2_INCLUDE="-I${SSL_OP_NO_TLSV1_2_DIR}/include"
+	fi
+	CPPFLAGS="${CPPFLAGS} ${SSL_OP_NO_TLSV1_2_INCLUDE}"
+
+	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+ #include <openssl/ssl.h>
+int
+main ()
+{
+#if defined(SSL_OP_NO_TLSv1_2)
+				int foo = 0;
+			        #else
+			        int foo = bar;
+			        #endif
+				0
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+     { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+		PBX_SSL_OP_NO_TLSV1_2=1
+
+$as_echo "#define HAVE_SSL_OP_NO_TLSV1_2 1" >>confdefs.h
+
+
+
+else
+     { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	CPPFLAGS="${saved_cppflags}"
+    fi
+
+
 fi
 
 

configure.ac

@@ -2265,6 +2265,12 @@ then
 	AST_EXT_LIB_CHECK([OPENSSL_EC], [ssl], [EC_KEY_new_by_curve_name], [openssl/ec.h], [-lcrypto])
 fi
 
+if test "$PBX_OPENSSL" = "1";
+then
+        AST_C_DEFINE_CHECK([SSL_OP_NO_TLSV1_1], [SSL_OP_NO_TLSv1_1], [openssl/ssl.h])
+        AST_C_DEFINE_CHECK([SSL_OP_NO_TLSV1_2], [SSL_OP_NO_TLSv1_2], [openssl/ssl.h])
+fi
+
 AST_EXT_LIB_CHECK([SRTP], [srtp], [srtp_init], [srtp/srtp.h])
 
 if test "$PBX_SRTP" = "1";

include/asterisk/autoconfig.h.in

@@ -816,6 +816,12 @@
 /* Define to 1 if you have the ISDN SS7 library. */
 #undef HAVE_SS7
 
+/* Define if your system has the SSL_OP_NO_TLSV1_1 headers. */
+#undef HAVE_SSL_OP_NO_TLSV1_1
+
+/* Define if your system has the SSL_OP_NO_TLSV1_2 headers. */
+#undef HAVE_SSL_OP_NO_TLSV1_2
+
 /* Define to 1 if `stat' has the bug that it succeeds when given the
    zero-length file name argument. */
 #undef HAVE_STAT_EMPTY_STRING_BUG

main/tcptls.c

@@ -811,12 +811,17 @@ static int __ssl_setup(struct ast_tls_config *cfg, int client)
 	if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV1)) {
 		ssl_opts |= SSL_OP_NO_TLSv1;
 	}
+#if defined(HAVE_SSL_OP_NO_TLSV1_1) && defined(HAVE_SSL_OP_NO_TLSV1_2)
 	if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV11)) {
 		ssl_opts |= SSL_OP_NO_TLSv1_1;
 	}
 	if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV12)) {
 		ssl_opts |= SSL_OP_NO_TLSv1_2;
 	}
+#else
+	ast_log(LOG_WARNING, "Your version of OpenSSL leaves you potentially vulnerable "
+			"to the SSL BEAST attack. Please upgrade to OpenSSL 1.0.1 or later\n");
+#endif
 
 	SSL_CTX_set_options(cfg->ssl_ctx, ssl_opts);