Commit 0351baae authored by Todd Short's avatar Todd Short
Browse files

Fix ALPN - more fixes 



* Clear proposed, along with selected, before looking at ClientHello
* Add test case for above
* Clear NPN seen after selecting ALPN on server
* Minor documentation updates

Reviewed-by: default avatarEmilia Käsper <emilia@openssl.org>
Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
parent 89ff989d

doc/ssl/SSL_CTX_set_alpn_select_cb.pod

+6 −6
Original line number Diff line number Diff line
@@ -2,8 +2,8 @@ 


=head1 NAME



SSL_CTX_set_alpn_select_cb, SSL_CTX_set_alpn_protos, SSL_set_alpn_protos,

SSL_get0_alpn_selected, SSL_select_next_proto - handle application layer

SSL_CTX_set_alpn_protos, SSL_set_alpn_protos, SSL_CTX_set_alpn_select_cb,

SSL_select_next_proto, SSL_get0_alpn_selected - handle application layer

protocol negotiation (ALPN)



=head1 SYNOPSIS
@@ -38,19 +38,19 @@ B<protos_len>. 


SSL_CTX_set_alpn_select_cb() sets the application callback B<cb> used by a

server to select which protocol to use for the incoming connection. When B<cb>

is NULL, no ALPN is not used. The B<arg> value is pointer which is passed to

is NULL, ALPN is not used. The B<arg> value is a pointer which is passed to

the application callback.



B<cb> is the application defined callback. The B<in>, B<inlen> parameters are a

vector in protocol-list format. The value of the B<out>, B<outlen> vector

should be set to the value of a single protocol contained with in the B<in>,

should be set to the value of a single protocol selected from the B<in>,

B<inlen> vector. The B<arg> parameter is the pointer set via

SSL_CTX_set_alpn_select_cb().



SSL_select_next_proto() is a helper function used to select protocols. It

implements the standard protocol selection. It is expected that this function

is called from the application callback B<cb>. The protocol data in B<server>,

B<server_len> and B<client>, B<client_len> must be in protocol-list format

B<server_len> and B<client>, B<client_len> must be in the protocol-list format

described below. The first item in the B<server>, B<server_len> list that

matches an item in the B<client>, B<client_len> list is selected, and returned

in B<out>, B<outlen>. The B<out> value will point into either B<server> or
@@ -60,7 +60,7 @@ function can also be used in the NPN callback. 


SSL_get0_alpn_selected() returns a pointer to the selected protocol in B<data>

with length B<len>. It is not NUL-terminated. B<data> is set to NULL and B<len>

is set to 0 if no protocol has been selected. B<data> value must not be freed.

is set to 0 if no protocol has been selected. B<data> must not be freed.



=head1 NOTES

ssl/t1_lib.c

+9 −6
Original line number Diff line number Diff line
@@ -1801,6 +1801,10 @@ static int tls1_alpn_handle_client_hello_late(SSL *s, int *ret, int *al) 
                return 0;

            }

            s->s3->alpn_selected_len = selected_len;

#ifndef OPENSSL_NO_NEXTPROTONEG

            /* ALPN takes precedence over NPN. */

            s->s3->next_proto_neg_seen = 0;

#endif

        } else {

            *al = SSL_AD_NO_APPLICATION_PROTOCOL;

            *ret = SSL_TLSEXT_ERR_ALERT_FATAL;
@@ -1902,6 +1906,10 @@ static int ssl_scan_clienthello_tlsext(SSL *s, PACKET *pkt, int *al) 


    OPENSSL_free(s->s3->alpn_selected);

    s->s3->alpn_selected = NULL;

    s->s3->alpn_selected_len = 0;

    OPENSSL_free(s->s3->alpn_proposed);

    s->s3->alpn_proposed = NULL;

    s->s3->alpn_proposed_len = 0;

#ifndef OPENSSL_NO_HEARTBEATS

    s->tlsext_heartbeat &= ~(SSL_DTLSEXT_HB_ENABLED |

                             SSL_DTLSEXT_HB_DONT_SEND_REQUESTS);
@@ -2216,8 +2224,7 @@ static int ssl_scan_clienthello_tlsext(SSL *s, PACKET *pkt, int *al) 
#endif

#ifndef OPENSSL_NO_NEXTPROTONEG

        else if (type == TLSEXT_TYPE_next_proto_neg &&

                 s->s3->tmp.finish_md_len == 0 &&

                 s->s3->alpn_selected == NULL) {

                 s->s3->tmp.finish_md_len == 0) {

            /*-

             * We shouldn't accept this extension on a

             * renegotiation.
@@ -2243,10 +2250,6 @@ static int ssl_scan_clienthello_tlsext(SSL *s, PACKET *pkt, int *al) 
                 s->s3->tmp.finish_md_len == 0) {

            if (!tls1_alpn_handle_client_hello(s, &extension, al))

                return 0;

#ifndef OPENSSL_NO_NEXTPROTONEG

            /* ALPN takes precedence over NPN. */

            s->s3->next_proto_neg_seen = 0;

#endif

        }



        /* session ticket processed earlier */

test/recipes/80-test_ssl.t

+6 −2
Original line number Diff line number Diff line
@@ -627,10 +627,10 @@ sub testssl { 
    subtest 'ALPN tests' => sub {

	######################################################################



	plan tests => 12;

	plan tests => 13;



      SKIP: {

	  skip "TLSv1.0 is not supported by this OpenSSL build", 12

	  skip "TLSv1.0 is not supported by this OpenSSL build", 13

	      if $no_tls1;



	  ok(run(test([@ssltest, "-bio_pair", "-tls1", "-alpn_client", "foo"])));
@@ -658,6 +658,10 @@ sub testssl { 
		       "-alpn_server1", "foo,123", "-sn_server1", "alice",

		       "-alpn_server2", "bar,456", "-sn_server2", "bob",

		       "-alpn_expected", "bar"])));

	  ok(run(test([@ssltest, "-bio_pair",

		       "-alpn_client", "foo,bar", "-sn_client", "bob",

		       "-alpn_server2", "bar,456", "-sn_server2", "bob",

		       "-alpn_expected", "bar"])));

	}

    };