X-Git-Url: https://www.bearssl.org/gitweb//home/git/?p=BearSSL;a=blobdiff_plain;f=src%2Fssl%2Fssl_hs_client.t0;h=4067b4d4a83a42d0abcc891605f59fcb124d125e;hp=37c554cd4dde2f2623cbdb330220ac969460692e;hb=bf809dfae527a99767f27ebcf5a83deac5999041;hpb=e61ad42191511226309bad2cbde8cd9e8cc743cb

diff --git a/src/ssl/ssl_hs_client.t0 b/src/ssl/ssl_hs_client.t0
index 37c554c..4067b4d 100644
--- a/src/ssl/ssl_hs_client.t0
+++ b/src/ssl/ssl_hs_client.t0
@@ -429,6 +429,21 @@ addr-ctx: hash_id
 : ext-point-format-length ( -- len )
 	supported-curves if 6 else 0 then ;
 
+\ Length of ALPN extension.
+cc: ext-ALPN-length ( -- len ) {
+	size_t u, len;
+
+	if (ENG->protocol_names_num == 0) {
+		T0_PUSH(0);
+		T0_RET();
+	}
+	len = 6;
+	for (u = 0; u < ENG->protocol_names_num; u ++) {
+		len += 1 + strlen(ENG->protocol_names[u]);
+	}
+	T0_PUSH(len);
+}
+
 \ Write handshake message: ClientHello
 : write-ClientHello ( -- )
 	{ ; total-ext-length }
@@ -438,6 +453,7 @@ addr-ctx: hash_id
 	ext-reneg-length ext-sni-length + ext-frag-length +
 	ext-signatures-length +
 	ext-supported-curves-length + ext-point-format-length +
+	ext-ALPN-length +
 	>total-ext-length
 
 	\ ClientHello type
@@ -542,6 +558,21 @@ addr-ctx: hash_id
 			0x0002 write16          \ extension length
 			0x0100 write16          \ value: 1 format: uncompressed
 		then
+		ext-ALPN-length dup if
+			0x0010 write16          \ extension type (16)
+			4 - dup write16         \ extension length
+			2- write16              \ list length
+			addr-protocol_names_num get16 0
+			begin
+				dup2 > while
+				dup copy-protocol-name
+				dup write8 addr-pad swap write-blob
+				1+
+			repeat
+			2drop
+		else
+			drop
+		then
 		ext-padding-amount 0< ifnot
 			0x0015 write16          \ extension value (21)
 			ext-padding-amount
@@ -595,6 +626,24 @@ addr-ctx: hash_id
 		then
 	then ;
 
+\ Read the ALPN extension from the server. It must contain a single name,
+\ and that name must match one of our names.
+: read-ALPN-from-server ( lim -- lim )
+	\ Extension contents length.
+	read16 open-elt
+	\ Length of list of names.
+	read16 open-elt
+	\ There should be a single name.
+	read8 addr-pad swap dup { len } read-blob
+	close-elt
+	close-elt
+	len test-protocol-name dup 0< if
+		3 flag? if ERR_UNEXPECTED fail then
+		drop
+	else
+		1+ addr-selected_protocol set16
+	then ;
+
 \ Save a value in a 16-bit field, or check it in case of session resumption.
 : check-resume ( val addr resume -- )
 	if get16 = ifnot ERR_RESUME_MISMATCH fail then else set16 then ;
@@ -688,6 +737,7 @@ cc: DEBUG-BLOB ( addr len -- ) {
 		ext-signatures-length { ok-signatures }
 		ext-supported-curves-length { ok-curves }
 		ext-point-format-length { ok-points }
+		ext-ALPN-length { ok-ALPN }
 		begin dup while
 			read16
 			case
@@ -753,6 +803,15 @@ cc: DEBUG-BLOB ( addr len -- ) {
 					read-ignore-16
 				endof
 
+				\ ALPN.
+				0x0010 of
+					ok-ALPN ifnot
+						ERR_EXTRA_EXTENSION fail
+					then
+					0 >ok-ALPN
+					read-ALPN-from-server
+				endof
+
 				ERR_EXTRA_EXTENSION fail
 			endcase
 		repeat
@@ -1102,6 +1161,7 @@ cc: do-client-sign ( -- sig_len ) {
 : do-handshake ( -- )
 	0 addr-application_data set8
 	22 addr-record_type_out set8
+	0 addr-selected_protocol set16
 	multihash-init
 
 	write-ClientHello