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-rw-r--r--lib/ssl/src/ssl_handshake.erl111
1 files changed, 91 insertions, 20 deletions
diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl
index 5c5f386c6f..493e5a87d9 100644
--- a/lib/ssl/src/ssl_handshake.erl
+++ b/lib/ssl/src/ssl_handshake.erl
@@ -136,6 +136,7 @@ client_hello_extensions(Host, Version, CipherSuites, SslOpts, ConnectionStates,
hash_signs = advertised_hash_signs(Version),
ec_point_formats = EcPointFormats,
elliptic_curves = EllipticCurves,
+ alpn = encode_alpn(SslOpts#ssl_options.alpn_advertised_protocols, Renegotiation),
next_protocol_negotiation =
encode_client_protocol_negotiation(SslOpts#ssl_options.next_protocol_selector,
Renegotiation),
@@ -764,6 +765,11 @@ encode_hello_extensions([], Acc) ->
Size = byte_size(Acc),
<<?UINT16(Size), Acc/binary>>;
+encode_hello_extensions([#alpn{extension_data = ExtensionData} | Rest], Acc) ->
+ Len = byte_size(ExtensionData),
+ ExtLen = Len + 2,
+ encode_hello_extensions(Rest, <<?UINT16(?ALPN_EXT), ?UINT16(ExtLen), ?UINT16(Len),
+ ExtensionData/binary, Acc/binary>>);
encode_hello_extensions([#next_protocol_negotiation{extension_data = ExtensionData} | Rest], Acc) ->
Len = byte_size(ExtensionData),
encode_hello_extensions(Rest, <<?UINT16(?NEXTPROTONEG_EXT), ?UINT16(Len),
@@ -862,6 +868,25 @@ decode_client_key(ClientKey, Type, Version) ->
decode_server_key(ServerKey, Type, Version) ->
dec_server_key(ServerKey, key_exchange_alg(Type), Version).
+%%
+%% Description: Encode and decode functions for ALPN extension data.
+%%--------------------------------------------------------------------
+
+%% While the RFC opens the door to allow ALPN during renegotiation, in practice
+%% this does not work and it is recommended to ignore any ALPN extension during
+%% renegotiation, as done here.
+encode_alpn(_, true) ->
+ undefined;
+encode_alpn(undefined, _) ->
+ undefined;
+encode_alpn(Protocols, _) ->
+ #alpn{extension_data = lists:foldl(fun encode_protocol/2, <<>>, Protocols)}.
+
+decode_alpn(undefined) ->
+ undefined;
+decode_alpn(#alpn{extension_data=Data}) ->
+ decode_protocols(Data, []).
+
encode_client_protocol_negotiation(undefined, _) ->
undefined;
encode_client_protocol_negotiation(_, false) ->
@@ -1124,8 +1149,10 @@ handle_client_hello_extensions(RecordCB, Random, ClientCipherSuites,
#hello_extensions{renegotiation_info = Info,
srp = SRP,
ec_point_formats = ECCFormat,
+ alpn = ALPN,
next_protocol_negotiation = NextProtocolNegotiation}, Version,
- #ssl_options{secure_renegotiate = SecureRenegotation} = Opts,
+ #ssl_options{secure_renegotiate = SecureRenegotation,
+ alpn_preferred_protocols = ALPNPreferredProtocols} = Opts,
#session{cipher_suite = NegotiatedCipherSuite,
compression_method = Compression} = Session0,
ConnectionStates0, Renegotiation) ->
@@ -1134,19 +1161,34 @@ handle_client_hello_extensions(RecordCB, Random, ClientCipherSuites,
Random, NegotiatedCipherSuite,
ClientCipherSuites, Compression,
ConnectionStates0, Renegotiation, SecureRenegotation),
- ProtocolsToAdvertise = handle_next_protocol_extension(NextProtocolNegotiation, Renegotiation, Opts),
-
+
ServerHelloExtensions = #hello_extensions{
renegotiation_info = renegotiation_info(RecordCB, server,
ConnectionStates, Renegotiation),
- ec_point_formats = server_ecc_extension(Version, ECCFormat),
- next_protocol_negotiation =
- encode_protocols_advertised_on_server(ProtocolsToAdvertise)
+ ec_point_formats = server_ecc_extension(Version, ECCFormat)
},
- {Session, ConnectionStates, ServerHelloExtensions}.
+
+ %% If we receive an ALPN extension and have ALPN configured for this connection,
+ %% we handle it. Otherwise we check for the NPN extension.
+ if
+ ALPN =/= undefined, ALPNPreferredProtocols =/= undefined ->
+ case handle_alpn_extension(ALPNPreferredProtocols, decode_alpn(ALPN)) of
+ #alert{} = Alert ->
+ Alert;
+ Protocol ->
+ {Session, ConnectionStates, Protocol,
+ ServerHelloExtensions#hello_extensions{alpn=encode_alpn([Protocol], Renegotiation)}}
+ end;
+ true ->
+ ProtocolsToAdvertise = handle_next_protocol_extension(NextProtocolNegotiation, Renegotiation, Opts),
+ {Session, ConnectionStates, undefined,
+ ServerHelloExtensions#hello_extensions{next_protocol_negotiation=
+ encode_protocols_advertised_on_server(ProtocolsToAdvertise)}}
+ end.
handle_server_hello_extensions(RecordCB, Random, CipherSuite, Compression,
#hello_extensions{renegotiation_info = Info,
+ alpn = ALPN,
next_protocol_negotiation = NextProtocolNegotiation}, Version,
#ssl_options{secure_renegotiate = SecureRenegotation,
next_protocol_selector = NextProtoSelector},
@@ -1155,11 +1197,23 @@ handle_server_hello_extensions(RecordCB, Random, CipherSuite, Compression,
CipherSuite, undefined,
Compression, ConnectionStates0,
Renegotiation, SecureRenegotation),
- case handle_next_protocol(NextProtocolNegotiation, NextProtoSelector, Renegotiation) of
- #alert{} = Alert ->
- Alert;
- Protocol ->
- {ConnectionStates, Protocol}
+
+ %% If we receive an ALPN extension then this is the protocol selected,
+ %% otherwise handle the NPN extension.
+ case decode_alpn(ALPN) of
+ %% ServerHello contains exactly one protocol: the one selected.
+ %% We also ignore the ALPN extension during renegotiation (see encode_alpn/2).
+ [Protocol] when not Renegotiation ->
+ {ConnectionStates, alpn, Protocol};
+ undefined ->
+ case handle_next_protocol(NextProtocolNegotiation, NextProtoSelector, Renegotiation) of
+ #alert{} = Alert ->
+ Alert;
+ Protocol ->
+ {ConnectionStates, npn, Protocol}
+ end;
+ _ -> %% {error, _Reason} or a list of 0/2+ protocols.
+ ?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE)
end.
select_version(RecordCB, ClientVersion, Versions) ->
@@ -1267,10 +1321,11 @@ hello_extensions_list(#hello_extensions{renegotiation_info = RenegotiationInfo,
hash_signs = HashSigns,
ec_point_formats = EcPointFormats,
elliptic_curves = EllipticCurves,
+ alpn = ALPN,
next_protocol_negotiation = NextProtocolNegotiation,
sni = Sni}) ->
[Ext || Ext <- [RenegotiationInfo, SRP, HashSigns,
- EcPointFormats, EllipticCurves, NextProtocolNegotiation, Sni], Ext =/= undefined].
+ EcPointFormats, EllipticCurves, ALPN, NextProtocolNegotiation, Sni], Ext =/= undefined].
srp_user(#ssl_options{srp_identity = {UserName, _}}) ->
#srp{username = UserName};
@@ -1708,6 +1763,10 @@ dec_server_key_signature(_, _, _) ->
dec_hello_extensions(<<>>, Acc) ->
Acc;
+dec_hello_extensions(<<?UINT16(?ALPN_EXT), ?UINT16(ExtLen), ?UINT16(Len), ExtensionData:Len/binary, Rest/binary>>, Acc)
+ when Len + 2 =:= ExtLen ->
+ ALPN = #alpn{extension_data = ExtensionData},
+ dec_hello_extensions(Rest, Acc#hello_extensions{alpn = ALPN});
dec_hello_extensions(<<?UINT16(?NEXTPROTONEG_EXT), ?UINT16(Len), ExtensionData:Len/binary, Rest/binary>>, Acc) ->
NextP = #next_protocol_negotiation{extension_data = ExtensionData},
dec_hello_extensions(Rest, Acc#hello_extensions{next_protocol_negotiation = NextP});
@@ -1788,18 +1847,19 @@ dec_sni(<<?BYTE(_), ?UINT16(Len), _:Len, Rest/binary>>) -> dec_sni(Rest);
dec_sni(_) -> undefined.
decode_next_protocols({next_protocol_negotiation, Protocols}) ->
- decode_next_protocols(Protocols, []).
-decode_next_protocols(<<>>, Acc) ->
+ decode_protocols(Protocols, []).
+
+decode_protocols(<<>>, Acc) ->
lists:reverse(Acc);
-decode_next_protocols(<<?BYTE(Len), Protocol:Len/binary, Rest/binary>>, Acc) ->
+decode_protocols(<<?BYTE(Len), Protocol:Len/binary, Rest/binary>>, Acc) ->
case Len of
0 ->
- {error, invalid_next_protocols};
+ {error, invalid_protocols};
_ ->
- decode_next_protocols(Rest, [Protocol|Acc])
+ decode_protocols(Rest, [Protocol|Acc])
end;
-decode_next_protocols(_Bytes, _Acc) ->
- {error, invalid_next_protocols}.
+decode_protocols(_Bytes, _Acc) ->
+ {error, invalid_protocols}.
%% encode/decode stream of certificate data to/from list of certificate data
certs_to_list(ASN1Certs) ->
@@ -1853,6 +1913,17 @@ key_exchange_alg(_) ->
%%-------------Extension handling --------------------------------
+%% Receive protocols, choose one from the list, return it.
+handle_alpn_extension(_, {error, _Reason}) ->
+ ?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE);
+handle_alpn_extension([], _) ->
+ ?ALERT_REC(?FATAL, ?NO_APPLICATION_PROTOCOL);
+handle_alpn_extension([ServerProtocol|Tail], ClientProtocols) ->
+ case lists:member(ServerProtocol, ClientProtocols) of
+ true -> ServerProtocol;
+ false -> handle_alpn_extension(Tail, ClientProtocols)
+ end.
+
handle_next_protocol(undefined,
_NextProtocolSelector, _Renegotiating) ->
undefined;
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-30 05:34:50 +0000