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-rw-r--r--lib/ssl/src/ssl_handshake.erl602
1 files changed, 374 insertions, 228 deletions
diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl
index ced3c2675e..1e57dfd710 100644
--- a/lib/ssl/src/ssl_handshake.erl
+++ b/lib/ssl/src/ssl_handshake.erl
@@ -57,10 +57,10 @@
]).
%% Encode
--export([encode_handshake/2, encode_hello_extensions/1,
+-export([encode_handshake/2, encode_hello_extensions/1, encode_extensions/1, encode_extensions/2,
encode_client_protocol_negotiation/2, encode_protocols_advertised_on_server/1]).
%% Decode
--export([decode_handshake/3, decode_hello_extensions/1,
+-export([decode_handshake/3, decode_vector/1, decode_hello_extensions/3, decode_extensions/1,
decode_server_key/3, decode_client_key/3,
decode_suites/2
]).
@@ -93,7 +93,7 @@ hello_request() ->
%%--------------------------------------------------------------------
-spec server_hello(#session{}, ssl_record:ssl_version(), ssl_record:connection_states(),
- #hello_extensions{}) -> #server_hello{}.
+ Extension::map()) -> #server_hello{}.
%%
%% Description: Creates a server hello message.
%%--------------------------------------------------------------------
@@ -532,7 +532,7 @@ encode_handshake(#server_hello{server_version = {Major, Minor},
session_id = Session_ID,
cipher_suite = CipherSuite,
compression_method = Comp_method,
- extensions = #hello_extensions{} = Extensions}, _Version) ->
+ extensions = Extensions}, _Version) ->
SID_length = byte_size(Session_ID),
ExtensionsBin = encode_hello_extensions(Extensions),
{?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32/binary,
@@ -582,93 +582,94 @@ encode_handshake(#certificate_verify{signature = BinSig, hashsign_algorithm = Ha
encode_handshake(#finished{verify_data = VerifyData}, _Version) ->
{?FINISHED, VerifyData}.
-encode_hello_extensions(#hello_extensions{} = Extensions) ->
- encode_hello_extensions(hello_extensions_list(Extensions), <<>>).
-encode_hello_extensions([], <<>>) ->
+encode_hello_extensions(Extensions) ->
+ encode_extensions(hello_extensions_list(Extensions), <<>>).
+
+encode_extensions(Exts) ->
+ encode_extensions(Exts, <<>>).
+
+encode_extensions([], <<>>) ->
<<>>;
-encode_hello_extensions([], Acc) ->
+encode_extensions([], Acc) ->
Size = byte_size(Acc),
<<?UINT16(Size), Acc/binary>>;
-
-encode_hello_extensions([#alpn{extension_data = ExtensionData} | Rest], Acc) ->
- Len = byte_size(ExtensionData),
+encode_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) ->
+ encode_extensions(Rest, <<?UINT16(?ALPN_EXT), ?UINT16(ExtLen), ?UINT16(Len),
+ ExtensionData/binary, Acc/binary>>);
+encode_extensions([#next_protocol_negotiation{extension_data = ExtensionData} | Rest], Acc) ->
Len = byte_size(ExtensionData),
- encode_hello_extensions(Rest, <<?UINT16(?NEXTPROTONEG_EXT), ?UINT16(Len),
+ encode_extensions(Rest, <<?UINT16(?NEXTPROTONEG_EXT), ?UINT16(Len),
ExtensionData/binary, Acc/binary>>);
-encode_hello_extensions([#renegotiation_info{renegotiated_connection = undefined} | Rest], Acc) ->
- encode_hello_extensions(Rest, Acc);
-encode_hello_extensions([#renegotiation_info{renegotiated_connection = ?byte(0) = Info} | Rest], Acc) ->
+encode_extensions([#renegotiation_info{renegotiated_connection = undefined} | Rest], Acc) ->
+ encode_extensions(Rest, Acc);
+encode_extensions([#renegotiation_info{renegotiated_connection = ?byte(0) = Info} | Rest], Acc) ->
Len = byte_size(Info),
- encode_hello_extensions(Rest, <<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), Info/binary, Acc/binary>>);
+ encode_extensions(Rest, <<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), Info/binary, Acc/binary>>);
-encode_hello_extensions([#renegotiation_info{renegotiated_connection = Info} | Rest], Acc) ->
+encode_extensions([#renegotiation_info{renegotiated_connection = Info} | Rest], Acc) ->
InfoLen = byte_size(Info),
Len = InfoLen +1,
- encode_hello_extensions(Rest, <<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), ?BYTE(InfoLen),
+ encode_extensions(Rest, <<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), ?BYTE(InfoLen),
Info/binary, Acc/binary>>);
-encode_hello_extensions([#elliptic_curves{elliptic_curve_list = EllipticCurves} | Rest], Acc) ->
+encode_extensions([#elliptic_curves{elliptic_curve_list = EllipticCurves} | Rest], Acc) ->
EllipticCurveList = << <<(tls_v1:oid_to_enum(X)):16>> || X <- EllipticCurves>>,
ListLen = byte_size(EllipticCurveList),
Len = ListLen + 2,
- encode_hello_extensions(Rest, <<?UINT16(?ELLIPTIC_CURVES_EXT),
+ encode_extensions(Rest, <<?UINT16(?ELLIPTIC_CURVES_EXT),
?UINT16(Len), ?UINT16(ListLen), EllipticCurveList/binary, Acc/binary>>);
-encode_hello_extensions([#ec_point_formats{ec_point_format_list = ECPointFormats} | Rest], Acc) ->
+encode_extensions([#ec_point_formats{ec_point_format_list = ECPointFormats} | Rest], Acc) ->
ECPointFormatList = list_to_binary(ECPointFormats),
ListLen = byte_size(ECPointFormatList),
Len = ListLen + 1,
- encode_hello_extensions(Rest, <<?UINT16(?EC_POINT_FORMATS_EXT),
+ encode_extensions(Rest, <<?UINT16(?EC_POINT_FORMATS_EXT),
?UINT16(Len), ?BYTE(ListLen), ECPointFormatList/binary, Acc/binary>>);
-encode_hello_extensions([#srp{username = UserName} | Rest], Acc) ->
+encode_extensions([#srp{username = UserName} | Rest], Acc) ->
SRPLen = byte_size(UserName),
Len = SRPLen + 2,
- encode_hello_extensions(Rest, <<?UINT16(?SRP_EXT), ?UINT16(Len), ?BYTE(SRPLen),
+ encode_extensions(Rest, <<?UINT16(?SRP_EXT), ?UINT16(Len), ?BYTE(SRPLen),
UserName/binary, Acc/binary>>);
-encode_hello_extensions([#hash_sign_algos{hash_sign_algos = HashSignAlgos} | Rest], Acc) ->
+encode_extensions([#hash_sign_algos{hash_sign_algos = HashSignAlgos} | Rest], Acc) ->
SignAlgoList = << <<(ssl_cipher:hash_algorithm(Hash)):8, (ssl_cipher:sign_algorithm(Sign)):8>> ||
{Hash, Sign} <- HashSignAlgos >>,
ListLen = byte_size(SignAlgoList),
Len = ListLen + 2,
- encode_hello_extensions(Rest, <<?UINT16(?SIGNATURE_ALGORITHMS_EXT),
+ encode_extensions(Rest, <<?UINT16(?SIGNATURE_ALGORITHMS_EXT),
?UINT16(Len), ?UINT16(ListLen), SignAlgoList/binary, Acc/binary>>);
-encode_hello_extensions([#signature_scheme_list{
+encode_extensions([#signature_scheme_list{
signature_scheme_list = SignatureSchemes} | Rest], Acc) ->
SignSchemeList = << <<(ssl_cipher:signature_scheme(SignatureScheme)):16 >> ||
SignatureScheme <- SignatureSchemes >>,
ListLen = byte_size(SignSchemeList),
Len = ListLen + 2,
- encode_hello_extensions(Rest, <<?UINT16(?SIGNATURE_ALGORITHMS_CERT_EXT),
+ encode_extensions(Rest, <<?UINT16(?SIGNATURE_ALGORITHMS_CERT_EXT),
?UINT16(Len), ?UINT16(ListLen), SignSchemeList/binary, Acc/binary>>);
-encode_hello_extensions([#sni{hostname = Hostname} | Rest], Acc) ->
+encode_extensions([#sni{hostname = Hostname} | Rest], Acc) ->
HostLen = length(Hostname),
HostnameBin = list_to_binary(Hostname),
% Hostname type (1 byte) + Hostname length (2 bytes) + Hostname (HostLen bytes)
ServerNameLength = 1 + 2 + HostLen,
% ServerNameListSize (2 bytes) + ServerNameLength
ExtLength = 2 + ServerNameLength,
- encode_hello_extensions(Rest, <<?UINT16(?SNI_EXT), ?UINT16(ExtLength),
- ?UINT16(ServerNameLength),
- ?BYTE(?SNI_NAMETYPE_HOST_NAME),
- ?UINT16(HostLen), HostnameBin/binary,
- Acc/binary>>);
-encode_hello_extensions([#client_hello_versions{versions = Versions0} | Rest], Acc) ->
+ encode_extensions(Rest, <<?UINT16(?SNI_EXT), ?UINT16(ExtLength),
+ ?UINT16(ServerNameLength),
+ ?BYTE(?SNI_NAMETYPE_HOST_NAME),
+ ?UINT16(HostLen), HostnameBin/binary,
+ Acc/binary>>);
+encode_extensions([#client_hello_versions{versions = Versions0} | Rest], Acc) ->
Versions = encode_versions(Versions0),
VerLen = byte_size(Versions),
Len = VerLen + 2,
- encode_hello_extensions(Rest, <<?UINT16(?SUPPORTED_VERSIONS_EXT),
+ encode_extensions(Rest, <<?UINT16(?SUPPORTED_VERSIONS_EXT),
?UINT16(Len), ?UINT16(VerLen), Versions/binary, Acc/binary>>);
-encode_hello_extensions([#server_hello_selected_version{selected_version = Version0} | Rest], Acc) ->
- Version = encode_versions(Version0),
+encode_extensions([#server_hello_selected_version{selected_version = Version0} | Rest], Acc) ->
+ Version = encode_versions([Version0]),
Len = byte_size(Version), %% 2
- encode_hello_extensions(Rest, <<?UINT16(?SUPPORTED_VERSIONS_EXT),
+ encode_extensions(Rest, <<?UINT16(?SUPPORTED_VERSIONS_EXT),
?UINT16(Len), Version/binary, Acc/binary>>).
-
-
encode_client_protocol_negotiation(undefined, _) ->
undefined;
encode_client_protocol_negotiation(_, false) ->
@@ -693,7 +694,7 @@ decode_handshake(_, ?NEXT_PROTOCOL, <<?BYTE(SelectedProtocolLength),
?BYTE(PaddingLength), _Padding:PaddingLength/binary>>) ->
#next_protocol{selected_protocol = SelectedProtocol};
-decode_handshake(_Version, ?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32/binary,
+decode_handshake(Version, ?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32/binary,
?BYTE(SID_length), Session_ID:SID_length/binary,
Cipher_suite:2/binary, ?BYTE(Comp_method)>>) ->
#server_hello{
@@ -702,14 +703,14 @@ decode_handshake(_Version, ?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:3
session_id = Session_ID,
cipher_suite = Cipher_suite,
compression_method = Comp_method,
- extensions = #hello_extensions{}};
+ extensions = empty_hello_extensions(Version, server)};
-decode_handshake(_Version, ?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32/binary,
+decode_handshake(Version, ?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32/binary,
?BYTE(SID_length), Session_ID:SID_length/binary,
Cipher_suite:2/binary, ?BYTE(Comp_method),
?UINT16(ExtLen), Extensions:ExtLen/binary>>) ->
- HelloExtensions = decode_hello_extensions(Extensions),
+ HelloExtensions = decode_hello_extensions(Extensions, Version, server),
#server_hello{
server_version = {Major,Minor},
@@ -752,17 +753,34 @@ decode_handshake(_Version, ?FINISHED, VerifyData) ->
decode_handshake(_, Message, _) ->
throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, {unknown_or_malformed_handshake, Message})).
+
+%%--------------------------------------------------------------------
+-spec decode_vector(binary()) -> binary().
+%%
+%% Description: Remove length tag from TLS Vector type. Needed
+%% for client hello when extensions in older versions may be empty.
+%%
+%%--------------------------------------------------------------------
+decode_vector(<<>>) ->
+ <<>>;
+decode_vector(<<?UINT16(Len), Vector:Len/binary>>) ->
+ Vector.
+
%%--------------------------------------------------------------------
--spec decode_hello_extensions({client, binary()} | binary()) -> #hello_extensions{}.
+-spec decode_hello_extensions(binary(), ssl_record:ssl_version(), client | server) -> map().
%%
%% Description: Decodes TLS hello extensions
%%--------------------------------------------------------------------
-decode_hello_extensions({client, <<>>}) ->
- #hello_extensions{};
-decode_hello_extensions({client, <<?UINT16(ExtLen), Extensions:ExtLen/binary>>}) ->
- decode_hello_extensions(Extensions);
-decode_hello_extensions(Extensions) ->
- dec_hello_extensions(Extensions, #hello_extensions{}).
+decode_hello_extensions(Extensions, Version, Role) ->
+ decode_extensions(Extensions, empty_hello_extensions(Version, Role)).
+
+%%--------------------------------------------------------------------
+-spec decode_extensions(binary()) -> map().
+%%
+%% Description: Decodes TLS hello extensions
+%%--------------------------------------------------------------------
+decode_extensions(Extensions) ->
+ decode_extensions(Extensions, empty_extensions()).
%%--------------------------------------------------------------------
-spec decode_server_key(binary(), ssl_cipher_format:key_algo(), ssl_record:ssl_version()) ->
@@ -979,57 +997,57 @@ client_hello_extensions(Version, CipherSuites,
end,
SRP = srp_user(SslOpts),
- HelloExtensions =
- #hello_extensions{
- renegotiation_info = renegotiation_info(tls_record, client,
- ConnectionStates, Renegotiation),
- srp = SRP,
- signature_algs = available_signature_algs(SupportedHashSigns, 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),
- sni = sni(SslOpts#ssl_options.server_name_indication)},
+ HelloExtensions = #{renegotiation_info => renegotiation_info(tls_record, client,
+ ConnectionStates, Renegotiation),
+ srp => SRP,
+ signature_algs => available_signature_algs(SupportedHashSigns, 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),
+ sni => sni(SslOpts#ssl_options.server_name_indication)
+ },
%% Add "supported_versions" extension if TLS 1.3
case Version of
{3,4} ->
- HelloExtensions#hello_extensions{
- client_hello_versions = #client_hello_versions{
- versions = Versions},
- signature_algs_cert = #signature_scheme_list{
- signature_scheme_list = SignatureSchemes}};
+ HelloExtensions#{client_hello_versions =>
+ #client_hello_versions{versions = Versions},
+ signature_algs_cert =>
+ signature_scheme_list(SignatureSchemes)};
_Else ->
HelloExtensions
end.
+signature_scheme_list(undefined) ->
+ undefined;
+signature_scheme_list(SignatureSchemes) ->
+ #signature_scheme_list{signature_scheme_list = SignatureSchemes}.
+
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,
+ Exts, Version,
#ssl_options{secure_renegotiate = SecureRenegotation,
alpn_preferred_protocols = ALPNPreferredProtocols} = Opts,
#session{cipher_suite = NegotiatedCipherSuite,
compression_method = Compression} = Session0,
ConnectionStates0, Renegotiation) ->
- Session = handle_srp_extension(SRP, Session0),
- ConnectionStates = handle_renegotiation_extension(server, RecordCB, Version, Info,
+ Session = handle_srp_extension(maps:get(srp, Exts, undefined), Session0),
+ ConnectionStates = handle_renegotiation_extension(server, RecordCB, Version, maps:get(renegotiation_info, Exts, undefined),
Random, NegotiatedCipherSuite,
ClientCipherSuites, Compression,
ConnectionStates0, Renegotiation, SecureRenegotation),
- ServerHelloExtensions = #hello_extensions{
- renegotiation_info = renegotiation_info(RecordCB, server,
- ConnectionStates, Renegotiation),
- ec_point_formats = server_ecc_extension(Version, ECCFormat)
- },
-
+ Empty = empty_hello_extensions(Version, client),
+ ServerHelloExtensions = Empty#{renegotiation_info => renegotiation_info(RecordCB, server,
+ ConnectionStates, Renegotiation),
+ ec_point_formats => server_ecc_extension(Version, maps:get(ec_point_formats, Exts, undefined))
+ },
+
%% If we receive an ALPN extension and have ALPN configured for this connection,
%% we handle it. Otherwise we check for the NPN extension.
+ ALPN = maps:get(alpn, Exts, undefined),
if
ALPN =/= undefined, ALPNPreferredProtocols =/= undefined ->
case handle_alpn_extension(ALPNPreferredProtocols, decode_alpn(ALPN)) of
@@ -1037,35 +1055,36 @@ handle_client_hello_extensions(RecordCB, Random, ClientCipherSuites,
Alert;
Protocol ->
{Session, ConnectionStates, Protocol,
- ServerHelloExtensions#hello_extensions{alpn=encode_alpn([Protocol], Renegotiation)}}
+ ServerHelloExtensions#{alpn => encode_alpn([Protocol], Renegotiation)}}
end;
true ->
+ NextProtocolNegotiation = maps:get(next_protocol_negotiation, Exts, undefined),
ProtocolsToAdvertise = handle_next_protocol_extension(NextProtocolNegotiation, Renegotiation, Opts),
{Session, ConnectionStates, undefined,
- ServerHelloExtensions#hello_extensions{next_protocol_negotiation=
- encode_protocols_advertised_on_server(ProtocolsToAdvertise)}}
+ ServerHelloExtensions#{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,
+ Exts, Version,
#ssl_options{secure_renegotiate = SecureRenegotation,
next_protocol_selector = NextProtoSelector},
ConnectionStates0, Renegotiation) ->
- ConnectionStates = handle_renegotiation_extension(client, RecordCB, Version, Info, Random,
+ ConnectionStates = handle_renegotiation_extension(client, RecordCB, Version, maps:get(renegotiation_info, Exts, undefined), Random,
CipherSuite, undefined,
Compression, ConnectionStates0,
Renegotiation, SecureRenegotation),
%% If we receive an ALPN extension then this is the protocol selected,
%% otherwise handle the NPN extension.
+ ALPN = maps:get(alpn, Exts, undefined),
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 ->
+ NextProtocolNegotiation = maps:get(next_protocol_negotiation, Exts, undefined),
case handle_next_protocol(NextProtocolNegotiation, NextProtoSelector, Renegotiation) of
#alert{} = Alert ->
Alert;
@@ -1114,26 +1133,50 @@ select_hashsign(_, _, KeyExAlgo, _, _Version) when KeyExAlgo == dh_anon;
{null, anon};
%% The signature_algorithms extension was introduced with TLS 1.2. Ignore it if we have
%% negotiated a lower version.
-select_hashsign(HashSigns, Cert, KeyExAlgo,
- undefined, {Major, Minor} = Version) when Major >= 3 andalso Minor >= 3->
- select_hashsign(HashSigns, Cert, KeyExAlgo, tls_v1:default_signature_algs(Version), Version);
-select_hashsign(#hash_sign_algos{hash_sign_algos = HashSigns}, Cert, KeyExAlgo, SupportedHashSigns,
- {Major, Minor}) when Major >= 3 andalso Minor >= 3 ->
- #'OTPCertificate'{tbsCertificate = TBSCert} = public_key:pkix_decode_cert(Cert, otp),
- #'OTPSubjectPublicKeyInfo'{algorithm = {_, SubjAlgo, _}} =
- TBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo,
-
- SubSign = sign_algo(SubjAlgo),
-
- case lists:filter(fun({_, S} = Algos) when S == SubSign ->
- is_acceptable_hash_sign(Algos, KeyExAlgo, SupportedHashSigns);
- (_) ->
- false
- end, HashSigns) of
- [] ->
- ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_signature_algorithm);
- [HashSign | _] ->
- HashSign
+select_hashsign({ClientHashSigns, ClientSignatureSchemes},
+ Cert, KeyExAlgo, undefined, {Major, Minor} = Version)
+ when Major >= 3 andalso Minor >= 3->
+ select_hashsign({ClientHashSigns, ClientSignatureSchemes}, Cert, KeyExAlgo,
+ tls_v1:default_signature_algs(Version), Version);
+select_hashsign({#hash_sign_algos{hash_sign_algos = ClientHashSigns},
+ ClientSignatureSchemes0},
+ Cert, KeyExAlgo, SupportedHashSigns, {Major, Minor})
+ when Major >= 3 andalso Minor >= 3 ->
+ ClientSignatureSchemes = get_signature_scheme(ClientSignatureSchemes0),
+ {SignAlgo0, Param, PublicKeyAlgo0} = get_cert_params(Cert),
+ SignAlgo = sign_algo(SignAlgo0),
+ PublicKeyAlgo = public_key_algo(PublicKeyAlgo0),
+
+ %% RFC 5246 (TLS 1.2)
+ %% If the client provided a "signature_algorithms" extension, then all
+ %% certificates provided by the server MUST be signed by a
+ %% hash/signature algorithm pair that appears in that extension.
+ %%
+ %% RFC 8446 (TLS 1.3)
+ %% TLS 1.3 provides two extensions for indicating which signature
+ %% algorithms may be used in digital signatures. The
+ %% "signature_algorithms_cert" extension applies to signatures in
+ %% certificates and the "signature_algorithms" extension, which
+ %% originally appeared in TLS 1.2, applies to signatures in
+ %% CertificateVerify messages.
+ %%
+ %% If no "signature_algorithms_cert" extension is
+ %% present, then the "signature_algorithms" extension also applies to
+ %% signatures appearing in certificates.
+ case is_supported_sign(SignAlgo, Param, ClientHashSigns, ClientSignatureSchemes) of
+ true ->
+ case lists:filter(fun({_, S} = Algos) when S == PublicKeyAlgo ->
+ is_acceptable_hash_sign(Algos, KeyExAlgo, SupportedHashSigns);
+ (_) ->
+ false
+ end, ClientHashSigns) of
+ [] ->
+ ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_signature_algorithm);
+ [HashSign | _] ->
+ HashSign
+ end;
+ false ->
+ ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_signature_algorithm)
end;
select_hashsign(_, Cert, _, _, Version) ->
#'OTPCertificate'{tbsCertificate = TBSCert} = public_key:pkix_decode_cert(Cert, otp),
@@ -1147,21 +1190,23 @@ select_hashsign(_, Cert, _, _, Version) ->
%%
%% Description: Handles signature algorithms selection for certificate requests (client)
%%--------------------------------------------------------------------
-select_hashsign(#certificate_request{hashsign_algorithms = #hash_sign_algos{hash_sign_algos = HashSigns},
- certificate_types = Types}, Cert, SupportedHashSigns,
+select_hashsign(#certificate_request{
+ hashsign_algorithms = #hash_sign_algos{
+ hash_sign_algos = HashSigns},
+ certificate_types = Types},
+ Cert,
+ SupportedHashSigns,
{Major, Minor}) when Major >= 3 andalso Minor >= 3->
- #'OTPCertificate'{tbsCertificate = TBSCert} = public_key:pkix_decode_cert(Cert, otp),
- #'OTPCertificate'{tbsCertificate = TBSCert,
- signatureAlgorithm = {_,SignAlgo, _}} = public_key:pkix_decode_cert(Cert, otp),
- #'OTPSubjectPublicKeyInfo'{algorithm = {_, SubjAlgo, _}} =
- TBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo,
-
- Sign = sign_algo(SignAlgo),
- SubSign = sign_algo(SubjAlgo),
-
- case is_acceptable_cert_type(SubSign, HashSigns, Types) andalso is_supported_sign(Sign, HashSigns) of
+ {SignAlgo0, Param, PublicKeyAlgo0} = get_cert_params(Cert),
+ SignAlgo = sign_algo(SignAlgo0),
+ PublicKeyAlgo = public_key_algo(PublicKeyAlgo0),
+
+ case is_acceptable_cert_type(PublicKeyAlgo, Types) andalso
+ %% certificate_request has no "signature_algorithms_cert"
+ %% extension in TLS 1.2.
+ is_supported_sign(SignAlgo, Param, HashSigns, undefined) of
true ->
- case lists:filter(fun({_, S} = Algos) when S == SubSign ->
+ case lists:filter(fun({_, S} = Algos) when S == PublicKeyAlgo ->
is_acceptable_hash_sign(Algos, SupportedHashSigns);
(_) ->
false
@@ -1174,8 +1219,38 @@ select_hashsign(#certificate_request{hashsign_algorithms = #hash_sign_algos{hash
false ->
?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_signature_algorithm)
end;
-select_hashsign(#certificate_request{}, Cert, _, Version) ->
- select_hashsign(undefined, Cert, undefined, [], Version).
+select_hashsign(#certificate_request{certificate_types = Types}, Cert, _, Version) ->
+ {_, _, PublicKeyAlgo0} = get_cert_params(Cert),
+ PublicKeyAlgo = public_key_algo(PublicKeyAlgo0),
+
+ %% Check cert even for TLS 1.0/1.1
+ case is_acceptable_cert_type(PublicKeyAlgo, Types) of
+ true ->
+ select_hashsign(undefined, Cert, undefined, [], Version);
+ false ->
+ ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_signature_algorithm)
+ end.
+
+
+%% Gets the relevant parameters of a certificate:
+%% - signature algorithm
+%% - parameters of the signature algorithm
+%% - public key algorithm (key type)
+get_cert_params(Cert) ->
+ #'OTPCertificate'{tbsCertificate = TBSCert,
+ signatureAlgorithm =
+ {_,SignAlgo, Param}} = public_key:pkix_decode_cert(Cert, otp),
+ #'OTPSubjectPublicKeyInfo'{algorithm = {_, PublicKeyAlgo, _}} =
+ TBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo,
+ {SignAlgo, Param, PublicKeyAlgo}.
+
+
+get_signature_scheme(undefined) ->
+ undefined;
+get_signature_scheme(#signature_scheme_list{
+ signature_scheme_list = ClientSignatureSchemes}) ->
+ ClientSignatureSchemes.
+
%%--------------------------------------------------------------------
-spec select_hashsign_algs({atom(), atom()}| undefined, oid(), ssl_record:ssl_version()) ->
@@ -1244,33 +1319,30 @@ int_to_bin(I) ->
L = (length(integer_to_list(I, 16)) + 1) div 2,
<<I:(L*8)>>.
-certificate_types(_, {N, M}) when N >= 3 andalso M >= 3 ->
- case proplists:get_bool(ecdsa,
- proplists:get_value(public_keys, crypto:supports())) of
- true ->
- <<?BYTE(?ECDSA_SIGN), ?BYTE(?RSA_SIGN), ?BYTE(?DSS_SIGN)>>;
- false ->
- <<?BYTE(?RSA_SIGN), ?BYTE(?DSS_SIGN)>>
- end;
-
-certificate_types(#{key_exchange := KeyExchange}, _) when KeyExchange == rsa;
- KeyExchange == dh_rsa;
- KeyExchange == dhe_rsa;
- KeyExchange == ecdhe_rsa ->
- <<?BYTE(?RSA_SIGN)>>;
-
-certificate_types(#{key_exchange := KeyExchange}, _) when KeyExchange == dh_dss;
- KeyExchange == dhe_dss;
- KeyExchange == srp_dss ->
- <<?BYTE(?DSS_SIGN)>>;
-
-certificate_types(#{key_exchange := KeyExchange}, _) when KeyExchange == dh_ecdsa;
- KeyExchange == dhe_ecdsa;
- KeyExchange == ecdh_ecdsa;
- KeyExchange == ecdhe_ecdsa ->
- <<?BYTE(?ECDSA_SIGN)>>;
+%% TLS 1.0+
+%% The end-entity certificate provided by the client MUST contain a
+%% key that is compatible with certificate_types.
+certificate_types(_, {N, M}) when N >= 3 andalso M >= 1 ->
+ ECDSA = supported_cert_type_or_empty(ecdsa, ?ECDSA_SIGN),
+ RSA = supported_cert_type_or_empty(rsa, ?RSA_SIGN),
+ DSS = supported_cert_type_or_empty(dss, ?DSS_SIGN),
+ <<ECDSA/binary,RSA/binary,DSS/binary>>;
+%% SSL 3.0
certificate_types(_, _) ->
- <<?BYTE(?RSA_SIGN)>>.
+ RSA = supported_cert_type_or_empty(rsa, ?RSA_SIGN),
+ DSS = supported_cert_type_or_empty(dss, ?DSS_SIGN),
+ <<RSA/binary,DSS/binary>>.
+
+%% Returns encoded certificate_type if algorithm is supported
+supported_cert_type_or_empty(Algo, Type) ->
+ case proplists:get_bool(
+ Algo,
+ proplists:get_value(public_keys, crypto:supports())) of
+ true ->
+ <<?BYTE(Type)>>;
+ false ->
+ <<>>
+ end.
certificate_authorities(CertDbHandle, CertDbRef) ->
Authorities = certificate_authorities_from_db(CertDbHandle, CertDbRef),
@@ -1823,21 +1895,8 @@ encode_versions([{M,N}|T], Acc) ->
encode_versions(T, <<?BYTE(M),?BYTE(N),Acc/binary>>).
-hello_extensions_list(#hello_extensions{renegotiation_info = RenegotiationInfo,
- srp = SRP,
- signature_algs = HashSigns,
- signature_algs_cert = SignatureSchemes,
- ec_point_formats = EcPointFormats,
- elliptic_curves = EllipticCurves,
- alpn = ALPN,
- next_protocol_negotiation = NextProtocolNegotiation,
- sni = Sni,
- client_hello_versions = Versions,
- server_hello_selected_version = Version}) ->
- [Ext || Ext <- [RenegotiationInfo, SRP, HashSigns, SignatureSchemes,
- EcPointFormats, EllipticCurves, ALPN,
- NextProtocolNegotiation, Sni,
- Versions, Version], Ext =/= undefined].
+hello_extensions_list(HelloExtensions) ->
+ [Ext || {_, Ext} <- maps:to_list(HelloExtensions), Ext =/= undefined].
%%-------------Decode handshakes---------------------------------
dec_server_key(<<?UINT16(PLen), P:PLen/binary,
@@ -1977,16 +2036,16 @@ dec_server_key_signature(Params, <<?UINT16(Len), Signature:Len/binary>>, _) ->
dec_server_key_signature(_, _, _) ->
throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, failed_to_decrypt_server_key_sign)).
-dec_hello_extensions(<<>>, Acc) ->
+decode_extensions(<<>>, Acc) ->
Acc;
-dec_hello_extensions(<<?UINT16(?ALPN_EXT), ?UINT16(ExtLen), ?UINT16(Len), ExtensionData:Len/binary, Rest/binary>>, Acc)
+decode_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) ->
+ decode_extensions(Rest, Acc#{alpn => ALPN});
+decode_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});
-dec_hello_extensions(<<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), Info:Len/binary, Rest/binary>>, Acc) ->
+ decode_extensions(Rest, Acc#{next_protocol_negotiation => NextP});
+decode_extensions(<<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), Info:Len/binary, Rest/binary>>, Acc) ->
RenegotiateInfo = case Len of
1 -> % Initial handshake
Info; % should be <<0>> will be matched in handle_renegotiation_info
@@ -1995,34 +2054,34 @@ dec_hello_extensions(<<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), Info:Len/binar
<<?BYTE(VerifyLen), VerifyInfo/binary>> = Info,
VerifyInfo
end,
- dec_hello_extensions(Rest, Acc#hello_extensions{renegotiation_info =
- #renegotiation_info{renegotiated_connection =
- RenegotiateInfo}});
+ decode_extensions(Rest, Acc#{renegotiation_info =>
+ #renegotiation_info{renegotiated_connection =
+ RenegotiateInfo}});
-dec_hello_extensions(<<?UINT16(?SRP_EXT), ?UINT16(Len), ?BYTE(SRPLen), SRP:SRPLen/binary, Rest/binary>>, Acc)
+decode_extensions(<<?UINT16(?SRP_EXT), ?UINT16(Len), ?BYTE(SRPLen), SRP:SRPLen/binary, Rest/binary>>, Acc)
when Len == SRPLen + 2 ->
- dec_hello_extensions(Rest, Acc#hello_extensions{srp = #srp{username = SRP}});
+ decode_extensions(Rest, Acc#{srp => #srp{username = SRP}});
-dec_hello_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_EXT), ?UINT16(Len),
+decode_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) ->
SignAlgoListLen = Len - 2,
<<?UINT16(SignAlgoListLen), SignAlgoList/binary>> = ExtData,
HashSignAlgos = [{ssl_cipher:hash_algorithm(Hash), ssl_cipher:sign_algorithm(Sign)} ||
<<?BYTE(Hash), ?BYTE(Sign)>> <= SignAlgoList],
- dec_hello_extensions(Rest, Acc#hello_extensions{signature_algs =
- #hash_sign_algos{hash_sign_algos = HashSignAlgos}});
+ decode_extensions(Rest, Acc#{signature_algs =>
+ #hash_sign_algos{hash_sign_algos = HashSignAlgos}});
-dec_hello_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_CERT_EXT), ?UINT16(Len),
+decode_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_CERT_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) ->
SignSchemeListLen = Len - 2,
<<?UINT16(SignSchemeListLen), SignSchemeList/binary>> = ExtData,
SignSchemes = [ssl_cipher:signature_scheme(SignScheme) ||
<<?UINT16(SignScheme)>> <= SignSchemeList],
- dec_hello_extensions(Rest, Acc#hello_extensions{signature_algs_cert =
- #signature_scheme_list{
- signature_scheme_list = SignSchemes}});
+ decode_extensions(Rest, Acc#{signature_algs_cert =>
+ #signature_scheme_list{
+ signature_scheme_list = SignSchemes}});
-dec_hello_extensions(<<?UINT16(?ELLIPTIC_CURVES_EXT), ?UINT16(Len),
+decode_extensions(<<?UINT16(?ELLIPTIC_CURVES_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) ->
<<?UINT16(_), EllipticCurveList/binary>> = ExtData,
%% Ignore unknown curves
@@ -2035,44 +2094,42 @@ dec_hello_extensions(<<?UINT16(?ELLIPTIC_CURVES_EXT), ?UINT16(Len),
end
end,
EllipticCurves = lists:filtermap(Pick, [ECC || <<ECC:16>> <= EllipticCurveList]),
- dec_hello_extensions(Rest, Acc#hello_extensions{elliptic_curves =
- #elliptic_curves{elliptic_curve_list =
- EllipticCurves}});
-dec_hello_extensions(<<?UINT16(?EC_POINT_FORMATS_EXT), ?UINT16(Len),
+ decode_extensions(Rest, Acc#{elliptic_curves =>
+ #elliptic_curves{elliptic_curve_list =
+ EllipticCurves}});
+decode_extensions(<<?UINT16(?EC_POINT_FORMATS_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) ->
<<?BYTE(_), ECPointFormatList/binary>> = ExtData,
ECPointFormats = binary_to_list(ECPointFormatList),
- dec_hello_extensions(Rest, Acc#hello_extensions{ec_point_formats =
- #ec_point_formats{ec_point_format_list =
- ECPointFormats}});
+ decode_extensions(Rest, Acc#{ec_point_formats =>
+ #ec_point_formats{ec_point_format_list =
+ ECPointFormats}});
-dec_hello_extensions(<<?UINT16(?SNI_EXT), ?UINT16(Len), Rest/binary>>, Acc) when Len == 0 ->
- dec_hello_extensions(Rest, Acc#hello_extensions{sni = #sni{hostname = ""}}); %% Server may send an empy SNI
+decode_extensions(<<?UINT16(?SNI_EXT), ?UINT16(Len), Rest/binary>>, Acc) when Len == 0 ->
+ decode_extensions(Rest, Acc#{sni => #sni{hostname = ""}}); %% Server may send an empy SNI
-dec_hello_extensions(<<?UINT16(?SNI_EXT), ?UINT16(Len),
+decode_extensions(<<?UINT16(?SNI_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) ->
<<?UINT16(_), NameList/binary>> = ExtData,
- dec_hello_extensions(Rest, Acc#hello_extensions{sni = dec_sni(NameList)});
+ decode_extensions(Rest, Acc#{sni => dec_sni(NameList)});
-dec_hello_extensions(<<?UINT16(?SUPPORTED_VERSIONS_EXT), ?UINT16(Len),
+decode_extensions(<<?UINT16(?SUPPORTED_VERSIONS_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) when Len > 2 ->
<<?UINT16(_),Versions/binary>> = ExtData,
- dec_hello_extensions(Rest, Acc#hello_extensions{
- client_hello_versions =
+ decode_extensions(Rest, Acc#{client_hello_versions =>
#client_hello_versions{versions = decode_versions(Versions)}});
-dec_hello_extensions(<<?UINT16(?SUPPORTED_VERSIONS_EXT), ?UINT16(Len),
+decode_extensions(<<?UINT16(?SUPPORTED_VERSIONS_EXT), ?UINT16(Len),
?UINT16(Version), Rest/binary>>, Acc) when Len =:= 2, Version =:= 16#0304 ->
- dec_hello_extensions(Rest, Acc#hello_extensions{
- server_hello_selected_version =
- #server_hello_selected_version{selected_version = [{3,4}]}});
+ decode_extensions(Rest, Acc#{server_hello_selected_version =>
+ #server_hello_selected_version{selected_version = {3,4}}});
%% Ignore data following the ClientHello (i.e.,
%% extensions) if not understood.
-dec_hello_extensions(<<?UINT16(_), ?UINT16(Len), _Unknown:Len/binary, Rest/binary>>, Acc) ->
- dec_hello_extensions(Rest, Acc);
+decode_extensions(<<?UINT16(_), ?UINT16(Len), _Unknown:Len/binary, Rest/binary>>, Acc) ->
+ decode_extensions(Rest, Acc);
%% This theoretically should not happen if the protocol is followed, but if it does it is ignored.
-dec_hello_extensions(_, Acc) ->
+decode_extensions(_, Acc) ->
Acc.
dec_hashsign(<<?BYTE(HashAlgo), ?BYTE(SignAlgo)>>) ->
@@ -2356,17 +2413,6 @@ handle_srp_extension(undefined, Session) ->
handle_srp_extension(#srp{username = Username}, Session) ->
Session#session{srp_username = Username}.
-
-sign_algo(?rsaEncryption) ->
- rsa;
-sign_algo(?'id-ecPublicKey') ->
- ecdsa;
-sign_algo(?'id-dsa') ->
- dsa;
-sign_algo(Alg) ->
- {_, Sign} =public_key:pkix_sign_types(Alg),
- Sign.
-
is_acceptable_hash_sign( _, KeyExAlgo, _) when
KeyExAlgo == psk;
KeyExAlgo == dhe_psk;
@@ -2382,15 +2428,80 @@ is_acceptable_hash_sign(Algos,_, SupportedHashSigns) ->
is_acceptable_hash_sign(Algos, SupportedHashSigns) ->
lists:member(Algos, SupportedHashSigns).
-is_acceptable_cert_type(Sign, _HashSigns, Types) ->
+is_acceptable_cert_type(Sign, Types) ->
lists:member(sign_type(Sign), binary_to_list(Types)).
-is_supported_sign(Sign, HashSigns) ->
- [] =/= lists:dropwhile(fun({_, S}) when S =/= Sign ->
- true;
- (_)->
- false
- end, HashSigns).
+%% signature_algorithms_cert = undefined
+is_supported_sign(SignAlgo, _, HashSigns, undefined) ->
+ lists:member(SignAlgo, HashSigns);
+
+%% {'SignatureAlgorithm',{1,2,840,113549,1,1,11},'NULL'}
+is_supported_sign({Hash, Sign}, 'NULL', _, SignatureSchemes) ->
+ Fun = fun (Scheme, Acc) ->
+ {H0, S0, _} = ssl_cipher:scheme_to_components(Scheme),
+ S1 = case S0 of
+ rsa_pkcs1 -> rsa;
+ S -> S
+ end,
+ H1 = case H0 of
+ sha1 -> sha;
+ H -> H
+ end,
+ Acc orelse (Sign =:= S1 andalso
+ Hash =:= H1)
+ end,
+ lists:foldl(Fun, false, SignatureSchemes);
+
+%% TODO: Implement validation for the curve used in the signature
+%% RFC 3279 - 2.2.3 ECDSA Signature Algorithm
+%% When the ecdsa-with-SHA1 algorithm identifier appears as the
+%% algorithm field in an AlgorithmIdentifier, the encoding MUST omit the
+%% parameters field. That is, the AlgorithmIdentifier SHALL be a
+%% SEQUENCE of one component: the OBJECT IDENTIFIER ecdsa-with-SHA1.
+%%
+%% The elliptic curve parameters in the subjectPublicKeyInfo field of
+%% the certificate of the issuer SHALL apply to the verification of the
+%% signature.
+is_supported_sign({Hash, Sign}, _Param, _, SignatureSchemes) ->
+ Fun = fun (Scheme, Acc) ->
+ {H0, S0, _} = ssl_cipher:scheme_to_components(Scheme),
+ S1 = case S0 of
+ rsa_pkcs1 -> rsa;
+ S -> S
+ end,
+ H1 = case H0 of
+ sha1 -> sha;
+ H -> H
+ end,
+ Acc orelse (Sign =:= S1 andalso
+ Hash =:= H1)
+ end,
+ lists:foldl(Fun, false, SignatureSchemes).
+
+%% SupportedPublicKeyAlgorithms PUBLIC-KEY-ALGORITHM-CLASS ::= {
+%% dsa | rsa-encryption | dh | kea | ec-public-key }
+public_key_algo(?rsaEncryption) ->
+ rsa;
+public_key_algo(?'id-ecPublicKey') ->
+ ecdsa;
+public_key_algo(?'id-dsa') ->
+ dsa.
+
+%% SupportedSignatureAlgorithms SIGNATURE-ALGORITHM-CLASS ::= {
+%% dsa-with-sha1 | dsaWithSHA1 | md2-with-rsa-encryption |
+%% md5-with-rsa-encryption | sha1-with-rsa-encryption | sha-1with-rsa-encryption |
+%% sha224-with-rsa-encryption |
+%% sha256-with-rsa-encryption |
+%% sha384-with-rsa-encryption |
+%% sha512-with-rsa-encryption |
+%% ecdsa-with-sha1 |
+%% ecdsa-with-sha224 |
+%% ecdsa-with-sha256 |
+%% ecdsa-with-sha384 |
+%% ecdsa-with-sha512 }
+sign_algo(Alg) ->
+ public_key:pkix_sign_types(Alg).
+
sign_type(rsa) ->
?RSA_SIGN;
sign_type(dsa) ->
@@ -2576,4 +2687,39 @@ cert_curve(Cert, ECCCurve0, CipherSuite) ->
{ECCCurve0, CipherSuite}
end.
-
+empty_hello_extensions({3, 4}, server) ->
+ #{server_hello_selected_version => undefined,
+ key_share => undefined,
+ pre_shared_key => undefined,
+ sni => undefined
+ };
+empty_hello_extensions({3, 4}, client) ->
+ #{client_hello_versions => undefined,
+ signature_algs => undefined,
+ signature_algs_cert => undefined,
+ sni => undefined,
+ alpn => undefined,
+ key_share => undefined,
+ pre_shared_key => undefined
+ };
+empty_hello_extensions({3, 3}, client) ->
+ Ext = empty_hello_extensions({3,2}, client),
+ Ext#{client_hello_versions => undefined,
+ signature_algs => undefined,
+ signature_algs_cert => undefined};
+empty_hello_extensions(_, client) ->
+ #{renegotiation_info => undefined,
+ alpn => undefined,
+ next_protocol_negotiation => undefined,
+ srp => undefined,
+ ec_point_formats => undefined,
+ elliptic_curves => undefined,
+ sni => undefined};
+empty_hello_extensions(_, server) ->
+ #{renegotiation_info => undefined,
+ alpn => undefined,
+ next_protocol_negotiation => undefined,
+ ec_point_formats => undefined,
+ sni => undefined}.
+empty_extensions() ->
+ #{}.