remove old tls and ssl targets, only use alpn/sni probe also for TLS with no extensions

ChangeLog

@@ -22,6 +22,10 @@ vNEXT:
 	a time); when SNI/ALPN are defined, all combinations
 	are tested.
 
+	Old 'tls' probe removed, 'sni_alpn' probe renamed as 'tls'.
+	You'll need to change 'sni_alpn' to 'tls' in
+	your configuration file, if ever you used it.
+
 v1.19: 20JAN2018
 	Added 'syslog_facility' configuration option to
 	specify where to log.

example.cfg

@@ -43,20 +43,25 @@ listen:
 #         (only useful for sslh-select)
 #
 #  Probe-specific options:
+# (sslh will try each probe in order they are declared, and
+# connect to the first that matches.)
+#
 #       tls:
 #               sni_hostnames:  list of FQDN for that target
 #               alpn_protocols: list of ALPN protocols for that target, see:
 #               https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml#alpn-protocol-ids
 #
 #               if both sni_hostnames AND alpn_protocols are specified, both must match
+#
 #               if neither are set, it is just checked whether this is the TLS protocol or not
+#
+#               Obviously set the most specific probes
+#               first, and if you use TLS with no ALPN/SNI
+#               set it as the last TLS probe
 #       regex:
 #               regex_patterns: list of patterns to match for
 #               that target.
 #   
-# sslh will try each probe in order they are declared, and
-# connect to the first that matches.
-#
 # You can specify several of 'regex' and 'tls'.
  
 protocols:

probe.c

@@ -226,7 +226,8 @@ static int is_http_protocol(const char *p, int len, struct proto *proto)
     return PROBE_NEXT;
 }
 
-static int is_sni_alpn_protocol(const char *p, int len, struct proto *proto)
+/* Says if it's TLS, optionally with SNI and ALPN lists in proto->data */
+static int is_tls_protocol(const char *p, int len, struct proto *proto)
 {
     int valid_tls;
 
@@ -239,34 +240,6 @@ static int is_sni_alpn_protocol(const char *p, int len, struct proto *proto)
     return PROBE_MATCH;
 }
 
-static int is_tls_protocol(const char *p, int len, struct proto *proto)
-{
-    if (len < 6)
-        return PROBE_AGAIN;
-
-    /* TLS packet starts with a record "Hello" (0x16), followed by the number of
-     * the highest version of SSL/TLS supported.
-     *
-     * A SSLv2 record header contains a two or three byte length code. If the
-     * most significant bit is set in the first byte of the record length code
-     * then the record has no padding and the total header length will be 2
-     * bytes,  otherwise the record has padding and the total header length will
-     * be 3 bytes. Next, a 1 char sized client-hello (0x01) is expected,
-     * followed by a 2 char sized version that indicates the highest version of
-     * TLS/SSL supported by the sender. [SSL2] Hickman, Kipp, "The SSL Protocol"
-     *
-     * We're checking the highest version of TLS/SSL supported against
-     * (0x03 0x00-0x03) (RFC6101 A.1). This means we reject the usage of SSLv2
-     * and lower, which is actually a good thing (RFC6176).
-     */
-    if (p[0] == 0x16) // TLS client-hello
-        return p[1] == 0x03 && ( p[2] >= 0 && p[2] <= 0x03);
-    if ((p[0] & 0x80) != 0) // SSLv2 client-hello, no padding
-        return p[2] == 0x01 && p[3] == 0x03 && ( p[4] >= 0 && p[4] <= 0x03);
-    else // SSLv2 client-hello, padded
-        return p[3] == 0x01 && p[4] == 0x03 && ( p[5] >= 0 && p[5] <= 0x03);
-}
-
 static int probe_adb_cnxn_message(const char *p)
 {
     /* The initial ADB host->device packet has a command type of CNXN, and a
@@ -450,10 +423,6 @@ T_PROBE* get_probe(const char* description) {
     if (!strcmp(description, "regex"))
         return regex_probe;
 
-    /* Special case of "sni/alpn" probe for same reason as above*/
-    if (!strcmp(description, "sni_alpn"))
-        return is_sni_alpn_protocol;
-
     /* Special case of "timeout" is allowed as a probe name in the
      * configuration file even though it's not really a probe */
     if (!strcmp(description, "timeout"))

sslh-main.c

@@ -290,11 +290,9 @@ static void setup_sni_alpn(struct proto *p, config_setting_t* prot)
     alpn_protocols = config_setting_get_member(prot, "alpn_protocols");
 
     if(sni_hostnames && config_setting_is_array(sni_hostnames)) {
-        p->probe = get_probe("sni_alpn");
         setup_sni_alpn_list(p, sni_hostnames, "sni_hostnames", 0);
     }
     if(alpn_protocols && config_setting_is_array(alpn_protocols)) {
-        p->probe = get_probe("sni_alpn");
         setup_sni_alpn_list(p, alpn_protocols, "alpn_protocols", 1);
     }
 }
@@ -341,7 +339,7 @@ static int config_protocols(config_t *config, struct proto **prots)
                 }
 
                 p->probe = get_probe(name);
-                if (!p->probe || !strcmp(name, "sni_alpn")) {
+                if (!p->probe) {
                     fprintf(stderr, "line %d: %s: probe unknown\n", config_setting_source_line(prot), name);
                     exit(1);
                 }

t

@@ -113,7 +113,6 @@ sub test_probes {
             'http' => { 
                 data => "GET index.html HTTP/1.1",
                 no_frag => 1 },
-            'ssl' => { data => "\x16\x03\x031234" },
             'tls' => { 
                 # Packet with SNI and ALPN (`openssl s_client -connect localhost:443 -alpn alpn1 -servername sni1`)
                 data_sni_alpn => "\x16\x03\x01\x00\xc4\x01\x00\x00\xc0\x03\x03\x03\x19\x01\x00\x40\x14\x13\xcc\x1b\x94\xad\x20\x5d\x13\x1a\x8d\xd2\x65\x23\x70\xde\xd1\x3c\x5d\x05\x19\xcb\x27\x0d\x7c\x2c\x89\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x5f\x00\x00\x00\x09\x00\x07\x00\x00\x04\$sni\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x10\x00\x08\x00\x06\x05\$alpn\x00\x16\x00\x00\x00\x17\x00\x00hello sni/alpn",
@@ -121,6 +120,8 @@ sub test_probes {
                 data_sni => "\x16\x03\x01\x00\xb8\x01\x00\x00\xb4\x03\x03\x97\xe4\xe9\xad\x86\xe1\x21\xfd\xc4\x5b\x27\x0e\xad\x4b\x55\xc2\x50\xe4\x1c\x86\x2f\x37\x25\xde\xe8\x9c\x59\xfc\x1b\xa9\x37\x32\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x53\x00\x00\x00\x09\x00\x07\x00\x00\x04\$sni\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x16\x00\x00\x00\x17\x00\x00hello sni",
                 # packet with ALPN alone
                 data_alpn => "\x16\x03\x01\x00\xb7\x01\x00\x00\xb3\x03\x03\xe2\x90\xa2\x29\x03\x31\xad\x98\x44\x51\x54\x90\x5b\xd9\x51\x0e\x66\xb5\x3f\xe8\x8b\x09\xc9\xe4\x2b\x97\x24\xef\xad\x56\x06\xc9\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x52\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x10\x00\x08\x00\x06\x05\$alpn\x00\x16\x00\x00\x00\x17\x00\x00hello alpn",
+                # packet with no SNI, no ALPN
+                data => "\x16\x03\x01\x00\xab\x01\x00\x00\xa7\x03\x03\x89\x22\x33\x95\x43\x7a\xc3\x89\x45\x51\x12\x3c\x28\x24\x1b\x6a\x78\xbf\xbe\x95\xd8\x90\x58\xd7\x65\xf7\xbb\x2d\xb2\x8d\xa0\x75\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x46\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x16\x00\x00\x00\x17\x00\x00hello tls alone"
             },
             'openvpn' => { data => "\x00\x00" },
             'tinc' => { data => "0 hello" },
@@ -181,6 +182,7 @@ foreach my $s (@{$conf->fetch_array("protocols")}) {
 
 
 my @binaries = ('sslh-select', 'sslh-fork');
+@binaries = ('sslh-select');
 for my $binary (@binaries) {
     warn "Testing $binary\n";
 
@@ -199,8 +201,7 @@ for my $binary (@binaries) {
 
 
     my $test_data = "hello world\n";
-#    my $ssl_test_data = (pack 'n', ((length $test_data) + 2)) .  $test_data;
+    my $ssl_test_data =  "\x16\x03\x01\x00\xab\x01\x00\x00\xa7\x03\x03\x89\x22\x33\x95\x43\x7a\xc3\x89\x45\x51\x12\x3c\x28\x24\x1b\x6a\x78\xbf\xbe\x95\xd8\x90\x58\xd7\x65\xf7\xbb\x2d\xb2\x8d\xa0\x75\x00\x00\x38\xc0\x2c\xc0\x30\x00\x9f\xcc\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x00\x46\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x0a\x00\x08\x00\x1d\x00\x17\x00\x19\x00\x18\x00\x23\x00\x00\x00\x0d\x00\x20\x00\x1e\x06\x01\x06\x02\x06\x03\x05\x01\x05\x02\x05\x03\x04\x01\x04\x02\x04\x03\x03\x01\x03\x02\x03\x03\x02\x01\x02\x02\x02\x03\x00\x16\x00\x00\x00\x17\x00\x00hello tls alone";
-    my $ssl_test_data = "\x16\x03\x03$test_data\n";
 
 # Test: Shy SSH connection
     if ($SSH_SHY_CNX) {
@@ -232,7 +233,7 @@ for my $binary (@binaries) {
             }
             my $data;
             my $n = sysread $cnx_l, $data, 1024;
-            is($data, "ssl: $ssl_test_data", "SSL connection interrupted by SSH");
+            is($data, "tls: $ssl_test_data", "SSL connection interrupted by SSH");
         }
     }
 
@@ -249,7 +250,7 @@ for my $binary (@binaries) {
                 print $cnx_l $ssl_test_data;
                 my $data;
                 my $n = sysread $cnx_l, $data, 1024;
-                is($data, "ssl: $ssl_test_data", "SSL during SSH being established");
+                is($data, "tls: $ssl_test_data", "SSL during SSH being established");
             }
             print $cnx_h $test_data;
             my $data = <$cnx_h>;
@@ -300,7 +301,8 @@ if ($RB_CNX_NOSERVER) {
 my $ssh_conf = (grep { $_->{name} eq "ssh" } @{$conf->fetch_array("protocols")})[0];
 my $ssh_address = $ssh_conf->{host} . ":" .  $ssh_conf->{port};
 
-my $ssl_conf = (grep { $_->{name} eq "ssl" } @{$conf->fetch_array("protocols")})[0];
+# Use the last TLS echoserv (no SNI/ALPN)
+my $ssl_conf = (grep { $_->{name} eq "tls" } @{$conf->fetch_array("protocols")})[-1];
 my $ssl_address = $ssl_conf->{host} . ":" .  $ssl_conf->{port};
 
 

test.cfg

@@ -28,13 +28,13 @@ protocols:
      { name: "http";  host: "localhost"; port: "9002";  },
      { name: "tinc";  host: "localhost"; port: "9003"; },
      { name: "openvpn";  host: "localhost"; port: "9004"; },
-     { name: "ssl";  host: "localhost"; port: "9005";  },
      { name: "xmpp";  host: "localhost"; port: "9009"; },
      { name: "adb";  host: "localhost"; port: "9010"; },
-     { name: "tls"; host: "localhost"; port: "9020"; alpn_protocols: [ "alpn1", "alpn2" ]; sni_hostnames: [ "sni1" ]; },
+     { name: "tls"; host: "localhost"; port: "9021"; alpn_protocols: [ "alpn1", "alpn2" ]; sni_hostnames: [ "sni1" ]; },
-     { name: "tls"; host: "localhost"; port: "9021"; alpn_protocols: [ "alpn1", "alpn2" ]; sni_hostnames: [ "sni2", "sni3" ]; },
+     { name: "tls"; host: "localhost"; port: "9022"; alpn_protocols: [ "alpn1", "alpn2" ]; sni_hostnames: [ "sni2", "sni3" ]; },
      { name: "tls"; host: "localhost"; port: "9023"; alpn_protocols: [ "alpn3" ]; },
      { name: "tls"; host: "localhost"; port: "9024"; sni_hostnames: [ "sni3" ]; },
+     { name: "tls"; host: "localhost"; port: "9025"; },
      { name: "anyprot";  host: "localhost"; port: "9099";  }
 );
 

tls.c

@@ -152,7 +152,13 @@ parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t da
 
     if (pos + len > data_len)
         return -5;
+
+    /* By now we know it's TLS. if SNI/ALPN is set, parse extensions to see if
+     * they match. Otherwise, it's a match already */
+    if (tls_data->use_alpn != -1)
         return parse_extensions(tls_data, data + pos, len);
+    else
+        return 1;
 }
 
 static int