Parse pre-shared-key extension.

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scripts/base/init-bare.zeek

@@ -4170,6 +4170,10 @@ export {
 		SignatureAlgorithm: count; ##< Signature algorithm number
 	};
 
+	type PSKIdentity: record {
+		identity: string; ##< PSK identity
+		obfuscated_ticket_age: count;
+	};
 
 ## Number of non-DTLS frames that can occur in a DTLS connection before
 ## parsing of the connection is suspended.
@@ -4191,6 +4195,8 @@ module GLOBAL;
 ##    directly and then remove this alias.
 type signature_and_hashalgorithm_vec: vector of SSL::SignatureAndHashAlgorithm;
 
+type psk_identity_vec: vector of SSL::PSKIdentity;
+
 module X509;
 export {
 	type Certificate: record {

src/analyzer/protocol/ssl/events.bif

@@ -182,6 +182,9 @@ event ssl_extension_signature_algorithm%(c: connection, is_orig: bool, signature
 ##    ssl_rsa_client_pms ssl_server_signature
 event ssl_extension_key_share%(c: connection, is_orig: bool, curves: index_vec%);
 
+event ssl_extension_pre_shared_key_client_hello%(c: connection, is_orig: bool, identities: psk_identity_vec, binders: string_vec%);
+event ssl_extension_pre_shared_key_server_hello%(c: connection, is_orig: bool, selected_identity: count%);
+
 ## Generated if a named curve is chosen by the server for an SSL/TLS connection.
 ## The curve is sent by the server in the ServerKeyExchange message as defined
 ## in :rfc:`4492`, in case an ECDH or ECDHE cipher suite is chosen.

src/analyzer/protocol/ssl/tls-handshake-analyzer.pac

@@ -411,6 +411,50 @@ refine connection Handshake_Conn += {
 		return true;
 		%}
 
+	function proc_pre_shared_key_server_hello(rec: HandshakeRecord, identities: PSKIdentitiesList, binders: PSKBindersList) : bool
+		%{
+		if ( ! ssl_extension_pre_shared_key_server_hello )
+			return true;
+
+		VectorVal* slist = new VectorVal(internal_type("psk_identity_vec")->AsVectorType());
+
+		if ( identities && identities->identities() )
+			{
+			uint32 i = 0;
+			for ( auto&& identity : *(identities->identities()) )
+				{
+				RecordVal* el = new RecordVal(BifType::Record::SSL::PSKIdentity);
+				el->Assign(0, new StringVal(identity->identity().length(), (const char*) identity->identity().data()));
+				el->Assign(1, val_mgr->GetCount(identity->obfuscated_ticket_age()));
+				slist->Assign(i++, el);
+				}
+			}
+
+		VectorVal* blist = new VectorVal(internal_type("string_vec")->AsVectorType());
+		if ( binders && binders->binders() )
+			{
+			uint32 i = 0;
+			for ( auto&& binder : *(binders->binders()) )
+				blist->Assign(i++, new StringVal(binder->binder().length(), (const char*) binder->binder().data()));
+			}
+
+		BifEvent::generate_ssl_extension_pre_shared_key_client_hello(bro_analyzer(), bro_analyzer()->Conn(),
+			${rec.is_orig}, slist, blist);
+
+		return true;
+		%}
+
+	function proc_pre_shared_key_client_hello(rec: HandshakeRecord, selected_identity: uint16) : bool
+		%{
+		if ( ! ssl_extension_pre_shared_key_client_hello )
+			return true;
+
+		BifEvent::generate_ssl_extension_pre_shared_key_server_hello(bro_analyzer(),
+			bro_analyzer()->Conn(), ${rec.is_orig}, selected_identity);
+
+		return true;
+		%}
+
 };
 
 refine typeattr ClientHello += &let {
@@ -520,6 +564,14 @@ refine typeattr PSKKeyExchangeModes += &let {
 	proc : bool = $context.connection.proc_psk_key_exchange_modes(rec, modes);
 };
 
+refine typeattr OfferedPsks += &let {
+	proc : bool = $context.connection.proc_pre_shared_key_server_hello(rec, identities, binders);
+};
+
+refine typeattr SelectedPreSharedKeyIdentity += &let {
+	proc : bool = $context.connection.proc_pre_shared_key_client_hello(rec, selected_identity);
+};
+
 refine typeattr Handshake += &let {
 	proc : bool = $context.connection.proc_handshake(rec.is_orig, rec.msg_type, rec.msg_length);
 };

src/analyzer/protocol/ssl/tls-handshake-protocol.pac

@@ -778,6 +778,7 @@ type SSLExtension(rec: HandshakeRecord) = record {
 		EXT_KEY_SHARE -> key_share: KeyShare(rec)[] &until($element == 0 || $element != 0);
 		EXT_SUPPORTED_VERSIONS -> supported_versions_selector: SupportedVersionsSelector(rec, data_len)[] &until($element == 0 || $element != 0);
 		EXT_PSK_KEY_EXCHANGE_MODES -> psk_key_exchange_modes: PSKKeyExchangeModes(rec)[] &until($element == 0 || $element != 0);
+		EXT_PRE_SHARED_KEY -> pre_shared_key: PreSharedKey(rec)[] &until($element == 0 || $element != 0);
 		default -> data: bytestring &restofdata;
 	};
 } &length=data_len+4 &exportsourcedata;
@@ -864,6 +865,43 @@ type KeyShare(rec: HandshakeRecord) = case rec.msg_type of {
 	default -> other : bytestring &restofdata &transient;
 };
 
+type SelectedPreSharedKeyIdentity(rec: HandshakeRecord) = record {
+	selected_identity: uint16;
+};
+
+type PSKIdentity() = record {
+	length: uint16;
+	identity: bytestring &length=length;
+	obfuscated_ticket_age: uint32;
+};
+
+type PSKIdentitiesList() = record {
+	length: uint16;
+	identities: PSKIdentity[] &until($input.length() == 0);
+} &length=length+2;
+
+type PSKBinder() = record {
+	length: uint8;
+	binder: bytestring &length=length;
+};
+
+type PSKBindersList() = record {
+	length: uint16;
+	binders: PSKBinder[] &until($input.length() == 0);
+} &length=length+2;
+
+type OfferedPsks(rec: HandshakeRecord) = record {
+	identities: PSKIdentitiesList;
+	binders: PSKBindersList;
+};
+
+type PreSharedKey(rec: HandshakeRecord) = case rec.msg_type of {
+	CLIENT_HELLO -> offered_psks : OfferedPsks(rec);
+	SERVER_HELLO -> selected_identity : SelectedPreSharedKeyIdentity(rec);
+	# ... well, we don't parse hello retry requests yet, because I don't have an example of them on the wire.
+	default -> other : bytestring &restofdata &transient;
+};
+
 type SignatureAlgorithm(rec: HandshakeRecord) = record {
 	length: uint16;
 	supported_signature_algorithms: SignatureAndHashAlgorithm[] &until($input.length() == 0);

src/analyzer/protocol/ssl/types.bif

@@ -1,5 +1,6 @@
 module SSL;
 
 type SignatureAndHashAlgorithm: record;
+type PSKIdentity: record;
 
 module GLOBAL;

testing/btest/Baseline/scripts.base.protocols.ssl.tls-extension-events/.stdout

@@ -45,7 +45,7 @@ sha1, dsa
 sha256, dsa
 sha384, dsa
 sha512, dsa
-supported_versions(, 192.168.6.240, 139.162.123.134
+supported_versions, 192.168.6.240, 139.162.123.134
 TLSv13-draft19
 TLSv12
 TLSv11
@@ -78,7 +78,7 @@ sha1, dsa
 sha256, dsa
 sha384, dsa
 sha512, dsa
-supported_versions(, 192.168.6.240, 139.162.123.134
+supported_versions, 192.168.6.240, 139.162.123.134
 TLSv13-draft19
 TLSv12
 TLSv11
@@ -86,3 +86,50 @@ TLSv10
 psk_key_exchange_modes, 192.168.6.240, 139.162.123.134
 1
 0
+pre_shared_key client hello, 192.168.6.240, 139.162.123.134, [[identity=\x01\xf3\x88\x12\xae\xeb\x13\x01\xed]\xcf\x0b\x8f\xad\xf2\xc1I\x9f-\xfa\xe1\x98\x9f\xb7\x82@\x81Or\x0e\xbe\xfc\xa3\xbc\x8f\x03\x86\xf1\x8e\xae\xd7\xe5\xa2\xee\xf3\xde\xb7\xa5\xf6\\xeb\x18^ICPm!|\x09\xe0NE\xe8\x0f\xda\xf8\xf2\xa8s\x84\x17>\xe5\xd9!\x19\x09\xfe\xdb\xa87\x05\xd7\xd06JG\xeb\xad\xf9\xf8\x13?#\xdc\xe7J\xad\x14\xbfS.\x98\xd8\xd2r\x01\xef\xc5\x0c_\xdf\xc9[7\xa7l\xa7\xa0\xb5\xda\x83\x16\x10\xa1\xdb\xe2<j\xfeN=uU\xd3\xf3[\x021\xb1\xff\xcc\xbbZ\x1d\xab\x14=\xca\x80\x07!d\x06\xbe\xc6\x90\x94\x92S\xcfu\x8e\x92_/\xc9\xf0H\xf3\xd0\xfa\xeb\xb6&, obfuscated_ticket_age=1415540021]], [\xdcJ$\x00L\x12\x87\x929wEed\xbd\xf6\xcb4\x04ip5\x95\xe2X\xca[Kx}\xadHY\xae\xab\xedz\xb3\xcaK=\xa0\x09ER\x0a\x8dO\xe4]
+pre_shared_key server hello, 192.168.6.240, 139.162.123.134, 0
+Point formats, 192.168.178.80, 174.138.9.219, T
+uncompressed
+ansiX962_compressed_prime
+ansiX962_compressed_char2
+Curves, 192.168.178.80, 174.138.9.219
+x25519
+secp256r1
+x448
+secp521r1
+secp384r1
+signature_algorithm, 192.168.178.80, 174.138.9.219
+sha256, ecdsa
+sha384, ecdsa
+sha512, ecdsa
+Intrinsic, ed25519
+Intrinsic, ed448
+Intrinsic, rsa_pss_sha256
+Intrinsic, rsa_pss_sha384
+Intrinsic, rsa_pss_sha512
+Intrinsic, rsa_pss_sha256
+Intrinsic, rsa_pss_sha384
+Intrinsic, rsa_pss_sha512
+sha256, rsa
+sha384, rsa
+sha512, rsa
+sha224, ecdsa
+sha1, ecdsa
+sha224, rsa
+sha1, rsa
+sha224, dsa
+sha1, dsa
+sha256, dsa
+sha384, dsa
+sha512, dsa
+supported_versions, 192.168.178.80, 174.138.9.219
+TLSv13
+TLSv12
+TLSv11
+TLSv10
+psk_key_exchange_modes, 192.168.178.80, 174.138.9.219
+1
+pre_shared_key client hello, 192.168.178.80, 174.138.9.219, [[identity=Client_identity, obfuscated_ticket_age=0]], [\xdbm7\xb6\xb9\xa3\xb29C\xb5\xa3\xa4\8\x95\x94o\x8d'\xd7\x99\x91R\xea\xcb\xa82\x9cb$e\xe9]
+supported_versions, 192.168.178.80, 174.138.9.219
+TLSv13
+pre_shared_key server hello, 192.168.178.80, 174.138.9.219, 0

testing/btest/scripts/base/protocols/ssl/tls-extension-events.test

@@ -1,5 +1,6 @@
 # @TEST-EXEC: bro -C -r $TRACES/tls/chrome-34-google.trace %INPUT
 # @TEST-EXEC: bro -C -r $TRACES/tls/tls-13draft19-early-data.pcap %INPUT
+# @TEST-EXEC: bro -C -r $TRACES/tls/tls13_psk_succesfull.pcap %INPUT
 # @TEST-EXEC: btest-diff .stdout
 
 event ssl_extension_elliptic_curves(c: connection, is_orig: bool, curves: index_vec)
@@ -37,7 +38,7 @@ event ssl_extension_signature_algorithm(c: connection, is_orig: bool, signature_
 
 event ssl_extension_supported_versions(c: connection, is_orig: bool, versions: index_vec)
 	{
-	print "supported_versions(", c$id$orig_h, c$id$resp_h;
+	print "supported_versions", c$id$orig_h, c$id$resp_h;
 	for ( i in versions )
 		print SSL::version_strings[versions[i]];
 	}
@@ -48,3 +49,14 @@ event ssl_extension_psk_key_exchange_modes(c: connection, is_orig: bool, modes:
 	for ( i in modes )
 		print modes[i];
 	}
+
+event ssl_extension_pre_shared_key_client_hello(c: connection, is_orig: bool, identities: psk_identity_vec, binders: string_vec)
+	{
+	print "pre_shared_key client hello", c$id$orig_h, c$id$resp_h, identities, binders;
+
+	}
+
+event ssl_extension_pre_shared_key_server_hello(c: connection, is_orig: bool, selected_identity: count)
+	{
+	print "pre_shared_key server hello", c$id$orig_h, c$id$resp_h, selected_identity;
+	}