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Diffstat (limited to 'lib/ssl/src/tls_handshake_1_3.erl')
-rw-r--r-- | lib/ssl/src/tls_handshake_1_3.erl | 734 |
1 files changed, 734 insertions, 0 deletions
diff --git a/lib/ssl/src/tls_handshake_1_3.erl b/lib/ssl/src/tls_handshake_1_3.erl new file mode 100644 index 0000000000..670c4d424d --- /dev/null +++ b/lib/ssl/src/tls_handshake_1_3.erl @@ -0,0 +1,734 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2007-2018. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% + +%%---------------------------------------------------------------------- +%% Purpose: Help funtions for handling the TLS 1.3 (specific parts of) +%%% TLS handshake protocol +%%---------------------------------------------------------------------- + +-module(tls_handshake_1_3). + +-include("tls_handshake_1_3.hrl"). +-include("ssl_alert.hrl"). +-include("ssl_cipher.hrl"). +-include("ssl_internal.hrl"). +-include("ssl_record.hrl"). +-include_lib("public_key/include/public_key.hrl"). + +%% Encode +-export([encode_handshake/1, decode_handshake/2]). + +%% Handshake +-export([handle_client_hello/3]). + +%% Create handshake messages +-export([certificate/5, + certificate_verify/5, + server_hello/4]). + +-export([do_negotiated/2]). + +%%==================================================================== +%% Create handshake messages +%%==================================================================== + +server_hello(SessionId, KeyShare, ConnectionStates, _Map) -> + #{security_parameters := SecParams} = + ssl_record:pending_connection_state(ConnectionStates, read), + Extensions = server_hello_extensions(KeyShare), + #server_hello{server_version = {3,3}, %% legacy_version + cipher_suite = SecParams#security_parameters.cipher_suite, + compression_method = 0, %% legacy attribute + random = SecParams#security_parameters.server_random, + session_id = SessionId, + extensions = Extensions + }. + +server_hello_extensions(KeyShare) -> + SupportedVersions = #server_hello_selected_version{selected_version = {3,4}}, + Extensions = #{server_hello_selected_version => SupportedVersions}, + ssl_handshake:add_server_share(Extensions, KeyShare). + + +%% TODO: use maybe monad for error handling! +certificate(OwnCert, CertDbHandle, CertDbRef, _CRContext, server) -> + case ssl_certificate:certificate_chain(OwnCert, CertDbHandle, CertDbRef) of + {ok, _, Chain} -> + CertList = chain_to_cert_list(Chain), + %% If this message is in response to a CertificateRequest, the value of + %% certificate_request_context in that message. Otherwise (in the case + %%of server authentication), this field SHALL be zero length. + #certificate_1_3{ + certificate_request_context = <<>>, + certificate_list = CertList}; + {error, Error} -> + ?ALERT_REC(?FATAL, ?INTERNAL_ERROR, {server_has_no_suitable_certificates, Error}) + end. + +%% TODO: use maybe monad for error handling! +certificate_verify(OwnCert, PrivateKey, SignatureScheme, Messages, server) -> + {HashAlgo, _, _} = + ssl_cipher:scheme_to_components(SignatureScheme), + + %% Transcript-Hash(Handshake Context, Certificate) + Context = [Messages, OwnCert], + THash = tls_v1:transcript_hash(Context, HashAlgo), + + Signature = digitally_sign(THash, <<"TLS 1.3, server CertificateVerify">>, + HashAlgo, PrivateKey), + + #certificate_verify_1_3{ + algorithm = SignatureScheme, + signature = Signature + }. + +%%==================================================================== +%% Encode handshake +%%==================================================================== + +encode_handshake(#certificate_request_1_3{ + certificate_request_context = Context, + extensions = Exts})-> + EncContext = encode_cert_req_context(Context), + BinExts = encode_extensions(Exts), + {?CERTIFICATE_REQUEST, <<EncContext/binary, BinExts/binary>>}; +encode_handshake(#certificate_1_3{ + certificate_request_context = Context, + certificate_list = Entries}) -> + EncContext = encode_cert_req_context(Context), + EncEntries = encode_cert_entries(Entries), + {?CERTIFICATE, <<EncContext/binary, EncEntries/binary>>}; +encode_handshake(#encrypted_extensions{extensions = Exts})-> + {?ENCRYPTED_EXTENSIONS, encode_extensions(Exts)}; +encode_handshake(#new_session_ticket{ + ticket_lifetime = LifeTime, + ticket_age_add = Age, + ticket_nonce = Nonce, + ticket = Ticket, + extensions = Exts}) -> + TicketSize = byte_size(Ticket), + BinExts = encode_extensions(Exts), + {?NEW_SESSION_TICKET, <<?UINT32(LifeTime), ?UINT32(Age), + ?BYTE(Nonce), ?UINT16(TicketSize), Ticket/binary, + BinExts/binary>>}; +encode_handshake(#end_of_early_data{}) -> + {?END_OF_EARLY_DATA, <<>>}; +encode_handshake(#key_update{request_update = Update}) -> + {?KEY_UPDATE, <<?BYTE(Update)>>}; +encode_handshake(HandshakeMsg) -> + ssl_handshake:encode_handshake(HandshakeMsg, {3,4}). + + +%%==================================================================== +%% Decode handshake +%%==================================================================== + +decode_handshake(?CERTIFICATE_REQUEST, <<?BYTE(0), ?UINT16(Size), EncExts:Size/binary>>) -> + Exts = decode_extensions(EncExts, certificate_request), + #certificate_request_1_3{ + certificate_request_context = <<>>, + extensions = Exts}; +decode_handshake(?CERTIFICATE_REQUEST, <<?BYTE(CSize), Context:CSize/binary, + ?UINT16(Size), EncExts:Size/binary>>) -> + Exts = decode_extensions(EncExts, certificate_request), + #certificate_request_1_3{ + certificate_request_context = Context, + extensions = Exts}; +decode_handshake(?CERTIFICATE, <<?BYTE(0), ?UINT24(Size), Certs:Size/binary>>) -> + CertList = decode_cert_entries(Certs), + #certificate_1_3{ + certificate_request_context = <<>>, + certificate_list = CertList + }; +decode_handshake(?CERTIFICATE, <<?BYTE(CSize), Context:CSize/binary, + ?UINT24(Size), Certs:Size/binary>>) -> + CertList = decode_cert_entries(Certs), + #certificate_1_3{ + certificate_request_context = Context, + certificate_list = CertList + }; +decode_handshake(?ENCRYPTED_EXTENSIONS, <<?UINT16(Size), EncExts:Size/binary>>) -> + #encrypted_extensions{ + extensions = decode_extensions(EncExts, encrypted_extensions) + }; +decode_handshake(?NEW_SESSION_TICKET, <<?UINT32(LifeTime), ?UINT32(Age), + ?BYTE(Nonce), ?UINT16(TicketSize), Ticket:TicketSize/binary, + BinExts/binary>>) -> + Exts = decode_extensions(BinExts, encrypted_extensions), + #new_session_ticket{ticket_lifetime = LifeTime, + ticket_age_add = Age, + ticket_nonce = Nonce, + ticket = Ticket, + extensions = Exts}; +decode_handshake(?END_OF_EARLY_DATA, _) -> + #end_of_early_data{}; +decode_handshake(?KEY_UPDATE, <<?BYTE(Update)>>) -> + #key_update{request_update = Update}; +decode_handshake(Tag, HandshakeMsg) -> + ssl_handshake:decode_handshake({3,4}, Tag, HandshakeMsg). + +%%-------------------------------------------------------------------- +%%% Internal functions +%%-------------------------------------------------------------------- +encode_cert_req_context(<<>>) -> + <<?BYTE(0)>>; +encode_cert_req_context(Bin) -> + Size = byte_size(Bin), + <<?BYTE(Size), Bin/binary>>. + +encode_cert_entries(Entries) -> + CertEntryList = encode_cert_entries(Entries, []), + Size = byte_size(CertEntryList), + <<?UINT24(Size), CertEntryList/binary>>. + +encode_cert_entries([], Acc) -> + iolist_to_binary(lists:reverse(Acc)); +encode_cert_entries([#certificate_entry{data = Data, + extensions = Exts} | Rest], Acc) -> + DSize = byte_size(Data), + BinExts = encode_extensions(Exts), + ExtSize = byte_size(BinExts), + encode_cert_entries(Rest, + [<<?UINT24(DSize), Data/binary, ?UINT16(ExtSize), BinExts/binary>> | Acc]). + +decode_cert_entries(Entries) -> + decode_cert_entries(Entries, []). + +decode_cert_entries(<<>>, Acc) -> + lists:reverse(Acc); +decode_cert_entries(<<?UINT24(DSize), Data:DSize/binary, ?UINT16(Esize), BinExts:Esize/binary, + Rest/binary>>, Acc) -> + Exts = decode_extensions(BinExts, certificate_request), + decode_cert_entries(Rest, [#certificate_entry{data = Data, + extensions = Exts} | Acc]). + +encode_extensions(Exts)-> + ssl_handshake:encode_extensions(extensions_list(Exts)). +decode_extensions(Exts, MessageType) -> + ssl_handshake:decode_extensions(Exts, {3,4}, MessageType). + +extensions_list(HelloExtensions) -> + [Ext || {_, Ext} <- maps:to_list(HelloExtensions)]. + + +%% TODO: add extensions! +chain_to_cert_list(L) -> + chain_to_cert_list(L, []). +%% +chain_to_cert_list([], Acc) -> + lists:reverse(Acc); +chain_to_cert_list([H|T], Acc) -> + chain_to_cert_list(T, [certificate_entry(H)|Acc]). + + +certificate_entry(DER) -> + #certificate_entry{ + data = DER, + extensions = #{} %% Extensions not supported. + }. + +%% The digital signature is then computed over the concatenation of: +%% - A string that consists of octet 32 (0x20) repeated 64 times +%% - The context string +%% - A single 0 byte which serves as the separator +%% - The content to be signed +%% +%% For example, if the transcript hash was 32 bytes of 01 (this length +%% would make sense for SHA-256), the content covered by the digital +%% signature for a server CertificateVerify would be: +%% +%% 2020202020202020202020202020202020202020202020202020202020202020 +%% 2020202020202020202020202020202020202020202020202020202020202020 +%% 544c5320312e332c207365727665722043657274696669636174655665726966 +%% 79 +%% 00 +%% 0101010101010101010101010101010101010101010101010101010101010101 +digitally_sign(THash, Context, HashAlgo, PrivateKey = #'RSAPrivateKey'{}) -> + Content = build_content(Context, THash), + + %% The length of the Salt MUST be equal to the length of the output + %% of the digest algorithm. + PadLen = ssl_cipher:hash_size(HashAlgo), + + public_key:sign(Content, HashAlgo, PrivateKey, + [{rsa_padding, rsa_pkcs1_pss_padding}, + {rsa_pss_saltlen, PadLen}]). + + +build_content(Context, THash) -> + <<" ", + " ", + Context/binary,?BYTE(0),THash/binary>>. + +%%==================================================================== +%% Handle handshake messages +%%==================================================================== + +handle_client_hello(#client_hello{cipher_suites = ClientCiphers, + session_id = SessionId, + extensions = Extensions} = _Hello, + #ssl_options{ciphers = ServerCiphers, + signature_algs = ServerSignAlgs, + signature_algs_cert = _SignatureSchemes, %% TODO: Check?? + supported_groups = ServerGroups0} = _SslOpts, + Env) -> + + Cert = maps:get(cert, Env, undefined), + + ClientGroups0 = maps:get(elliptic_curves, Extensions, undefined), + ClientGroups = get_supported_groups(ClientGroups0), + ServerGroups = get_supported_groups(ServerGroups0), + + ClientShares0 = maps:get(key_share, Extensions, undefined), + ClientShares = get_key_shares(ClientShares0), + + ClientSignAlgs = get_signature_scheme_list( + maps:get(signature_algs, Extensions, undefined)), + ClientSignAlgsCert = get_signature_scheme_list( + maps:get(signature_algs_cert, Extensions, undefined)), + + %% TODO: use library function if it exists + %% Init the maybe "monad" + {Ref,Maybe} = maybe(), + + try + %% If the server does not select a PSK, then the server independently selects a + %% cipher suite, an (EC)DHE group and key share for key establishment, + %% and a signature algorithm/certificate pair to authenticate itself to + %% the client. + Cipher = Maybe(select_cipher_suite(ClientCiphers, ServerCiphers)), + Group = Maybe(select_server_group(ServerGroups, ClientGroups)), + Maybe(validate_key_share(ClientGroups, ClientShares)), + + ClientPubKey = Maybe(get_client_public_key(Group, ClientShares)), + + {PublicKeyAlgo, SignAlgo, SignHash} = get_certificate_params(Cert), + + %% Check if client supports signature algorithm of server certificate + Maybe(check_cert_sign_algo(SignAlgo, SignHash, ClientSignAlgs, ClientSignAlgsCert)), + + %% Select signature algorithm (used in CertificateVerify message). + SelectedSignAlg = Maybe(select_sign_algo(PublicKeyAlgo, ClientSignAlgs, ServerSignAlgs)), + + %% Generate server_share + KeyShare = ssl_cipher:generate_server_share(Group), + _Ret = #{cipher => Cipher, + group => Group, + sign_alg => SelectedSignAlg, + client_share => ClientPubKey, + key_share => KeyShare, + session_id => SessionId} + + %% TODO: + %% - session handling + %% - handle extensions: ALPN + %% (do not handle: NPN, srp, renegotiation_info, ec_point_formats) + + catch + {Ref, {insufficient_security, no_suitable_groups}} -> + ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_groups); + {Ref, illegal_parameter} -> + ?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER); + {Ref, {hello_retry_request, _Group0}} -> + %% TODO + ?ALERT_REC(?FATAL, ?INTERNAL_ERROR, "hello_retry_request not implemented"); + {Ref, no_suitable_cipher} -> + ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_cipher); + {Ref, {insufficient_security, no_suitable_signature_algorithm}} -> + ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_signature_algorithm); + {Ref, {insufficient_security, no_suitable_public_key}} -> + ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY, no_suitable_public_key) + end. + + +do_negotiated(#{client_share := ClientKey, + group := SelectedGroup, + sign_alg := SignatureScheme + } = Map, + #{connection_states := ConnectionStates0, + session_id := SessionId, + own_certificate := OwnCert, + cert_db := CertDbHandle, + cert_db_ref := CertDbRef, + ssl_options := SslOpts, + key_share := KeyShare, + tls_handshake_history := HHistory0, + transport_cb := Transport, + socket := Socket, + private_key := CertPrivateKey}) -> + {Ref,Maybe} = maybe(), + + try + %% Create server_hello + %% Extensions: supported_versions, key_share, (pre_shared_key) + ServerHello = server_hello(SessionId, KeyShare, ConnectionStates0, Map), + + %% Update handshake_history (done in encode!) + %% Encode handshake + {BinMsg, ConnectionStates1, HHistory1} = + tls_connection:encode_handshake(ServerHello, {3,4}, ConnectionStates0, HHistory0), + %% Send server_hello + tls_connection:send(Transport, Socket, BinMsg), + log_handshake(SslOpts, ServerHello), + log_tls_record(SslOpts, BinMsg), + + %% ConnectionStates2 = calculate_security_parameters(ClientKey, SelectedGroup, KeyShare, + %% HHistory1, ConnectionStates1), + {HandshakeSecret, ReadKey, ReadIV, WriteKey, WriteIV} = + calculate_security_parameters(ClientKey, SelectedGroup, KeyShare, + HHistory1, ConnectionStates1), + ConnectionStates2 = + update_pending_connection_states(ConnectionStates1, HandshakeSecret, + ReadKey, ReadIV, WriteKey, WriteIV), + ConnectionStates3 = + ssl_record:step_encryption_state(ConnectionStates2), + + %% Create Certificate + Certificate = certificate(OwnCert, CertDbHandle, CertDbRef, <<>>, server), + + %% Encode Certificate + {_, _ConnectionStates4, HHistory2} = + tls_connection:encode_handshake(Certificate, {3,4}, ConnectionStates3, HHistory1), + %% log_handshake(SslOpts, Certificate), + + %% Create CertificateVerify + {Messages, _} = HHistory2, + + %% Use selected signature_alg from here, HKDF only used for key_schedule + CertificateVerify = + tls_handshake_1_3:certificate_verify(OwnCert, CertPrivateKey, SignatureScheme, + Messages, server), + io:format("### CertificateVerify: ~p~n", [CertificateVerify]), + + %% Encode CertificateVerify + + %% Send Certificate, CertifricateVerify + + %% Send finished + + %% Next record/Next event + + Maybe(not_implemented(negotiated)) + + + catch + {Ref, {state_not_implemented, State}} -> + %% TODO + ?ALERT_REC(?FATAL, ?INTERNAL_ERROR, {state_not_implemented, State}) + end. + + +%% TODO: Remove this function! +not_implemented(State) -> + {error, {state_not_implemented, State}}. + + +log_handshake(SslOpts, Message) -> + Msg = #{direction => outbound, + protocol => 'handshake', + message => Message}, + ssl_logger:debug(SslOpts#ssl_options.log_level, Msg, #{domain => [otp,ssl,handshake]}). + + +log_tls_record(SslOpts, BinMsg) -> + Report = #{direction => outbound, + protocol => 'tls_record', + message => BinMsg}, + ssl_logger:debug(SslOpts#ssl_options.log_level, Report, #{domain => [otp,ssl,tls_record]}). + + +calculate_security_parameters(ClientKey, SelectedGroup, KeyShare, HHistory, ConnectionStates) -> + #{security_parameters := SecParamsR} = + ssl_record:pending_connection_state(ConnectionStates, read), + #security_parameters{prf_algorithm = HKDFAlgo, + cipher_suite = CipherSuite} = SecParamsR, + + %% Calculate handshake_secret + EarlySecret = tls_v1:key_schedule(early_secret, HKDFAlgo , {psk, <<>>}), + PrivateKey = get_server_private_key(KeyShare), %% #'ECPrivateKey'{} + + IKM = calculate_shared_secret(ClientKey, PrivateKey, SelectedGroup), + HandshakeSecret = tls_v1:key_schedule(handshake_secret, HKDFAlgo, IKM, EarlySecret), + + %% Calculate [sender]_handshake_traffic_secret + {Messages, _} = HHistory, + ClientHSTrafficSecret = + tls_v1:client_handshake_traffic_secret(HKDFAlgo, HandshakeSecret, lists:reverse(Messages)), + ServerHSTrafficSecret = + tls_v1:server_handshake_traffic_secret(HKDFAlgo, HandshakeSecret, lists:reverse(Messages)), + + %% Calculate traffic keys + #{cipher := Cipher} = ssl_cipher_format:suite_definition(CipherSuite), + {ReadKey, ReadIV} = tls_v1:calculate_traffic_keys(HKDFAlgo, Cipher, ClientHSTrafficSecret), + {WriteKey, WriteIV} = tls_v1:calculate_traffic_keys(HKDFAlgo, Cipher, ServerHSTrafficSecret), + + {HandshakeSecret, ReadKey, ReadIV, WriteKey, WriteIV}. + + %% %% Update pending connection state + %% PendingRead0 = ssl_record:pending_connection_state(ConnectionStates, read), + %% PendingWrite0 = ssl_record:pending_connection_state(ConnectionStates, write), + + %% PendingRead = update_conn_state(PendingRead0, HandshakeSecret, ReadKey, ReadIV), + %% PendingWrite = update_conn_state(PendingWrite0, HandshakeSecret, WriteKey, WriteIV), + + %% %% Update pending and copy to current (activate) + %% %% All subsequent handshake messages are encrypted + %% %% ([sender]_handshake_traffic_secret) + %% #{current_read => PendingRead, + %% current_write => PendingWrite, + %% pending_read => PendingRead, + %% pending_write => PendingWrite}. + + +get_server_private_key(#key_share_server_hello{server_share = ServerShare}) -> + get_private_key(ServerShare). + +get_private_key(#key_share_entry{ + key_exchange = #'ECPrivateKey'{} = PrivateKey}) -> + PrivateKey; +get_private_key(#key_share_entry{ + key_exchange = + {_, PrivateKey}}) -> + PrivateKey. + +%% X25519, X448 +calculate_shared_secret(OthersKey, MyKey, Group) + when is_binary(OthersKey) andalso is_binary(MyKey) andalso + (Group =:= x25519 orelse Group =:= x448)-> + crypto:compute_key(ecdh, OthersKey, MyKey, Group); +%% FFDHE +calculate_shared_secret(OthersKey, MyKey, Group) + when is_binary(OthersKey) andalso is_binary(MyKey) -> + Params = #'DHParameter'{prime = P} = ssl_dh_groups:dh_params(Group), + S = public_key:compute_key(OthersKey, MyKey, Params), + Size = byte_size(binary:encode_unsigned(P)), + ssl_cipher:add_zero_padding(S, Size); +%% ECDHE +calculate_shared_secret(OthersKey, MyKey = #'ECPrivateKey'{}, _Group) + when is_binary(OthersKey) -> + Point = #'ECPoint'{point = OthersKey}, + public_key:compute_key(Point, MyKey). + + +update_pending_connection_states(CS = #{pending_read := PendingRead0, + pending_write := PendingWrite0}, + HandshakeSecret, ReadKey, ReadIV, WriteKey, WriteIV) -> + PendingRead = update_connection_state(PendingRead0, HandshakeSecret, ReadKey, ReadIV), + PendingWrite = update_connection_state(PendingWrite0, HandshakeSecret, WriteKey, WriteIV), + CS#{pending_read => PendingRead, + pending_write => PendingWrite}. + +update_connection_state(ConnectionState = #{security_parameters := SecurityParameters0}, + HandshakeSecret, Key, IV) -> + %% Store secret + SecurityParameters = SecurityParameters0#security_parameters{ + master_secret = HandshakeSecret}, + ConnectionState#{security_parameters => SecurityParameters, + cipher_state => cipher_init(Key, IV)}. + + + +cipher_init(Key, IV) -> + #cipher_state{key = Key, iv = IV, tag_len = 16}. + + +%% If there is no overlap between the received +%% "supported_groups" and the groups supported by the server, then the +%% server MUST abort the handshake with a "handshake_failure" or an +%% "insufficient_security" alert. +select_server_group(_, []) -> + {error, {insufficient_security, no_suitable_groups}}; +select_server_group(ServerGroups, [C|ClientGroups]) -> + case lists:member(C, ServerGroups) of + true -> + {ok, C}; + false -> + select_server_group(ServerGroups, ClientGroups) + end. + + +%% RFC 8446 - 4.2.8. Key Share +%% This vector MAY be empty if the client is requesting a +%% HelloRetryRequest. Each KeyShareEntry value MUST correspond to a +%% group offered in the "supported_groups" extension and MUST appear in +%% the same order. However, the values MAY be a non-contiguous subset +%% of the "supported_groups" extension and MAY omit the most preferred +%% groups. +%% +%% Clients can offer as many KeyShareEntry values as the number of +%% supported groups it is offering, each representing a single set of +%% key exchange parameters. +%% +%% Clients MUST NOT offer multiple KeyShareEntry values +%% for the same group. Clients MUST NOT offer any KeyShareEntry values +%% for groups not listed in the client's "supported_groups" extension. +%% Servers MAY check for violations of these rules and abort the +%% handshake with an "illegal_parameter" alert if one is violated. +validate_key_share(_ ,[]) -> + ok; +validate_key_share([], _) -> + {error, illegal_parameter}; +validate_key_share([G|ClientGroups], [{_, G, _}|ClientShares]) -> + validate_key_share(ClientGroups, ClientShares); +validate_key_share([_|ClientGroups], [_|_] = ClientShares) -> + validate_key_share(ClientGroups, ClientShares). + + +get_client_public_key(Group, ClientShares) -> + case lists:keysearch(Group, 2, ClientShares) of + {value, {_, _, ClientPublicKey}} -> + {ok, ClientPublicKey}; + false -> + %% 4.1.4. Hello Retry Request + %% + %% The server will send this message in response to a ClientHello + %% message if it is able to find an acceptable set of parameters but the + %% ClientHello does not contain sufficient information to proceed with + %% the handshake. + {error, {hello_retry_request, Group}} + end. + +select_cipher_suite([], _) -> + {error, no_suitable_cipher}; +select_cipher_suite([Cipher|ClientCiphers], ServerCiphers) -> + case lists:member(Cipher, tls_v1:suites('TLS_v1.3')) andalso + lists:member(Cipher, ServerCiphers) of + true -> + {ok, Cipher}; + false -> + select_cipher_suite(ClientCiphers, ServerCiphers) + end. + +%% 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. + +%% Check if the signature algorithm of the server certificate is supported +%% by the client. +check_cert_sign_algo(SignAlgo, SignHash, ClientSignAlgs, undefined) -> + do_check_cert_sign_algo(SignAlgo, SignHash, ClientSignAlgs); +check_cert_sign_algo(SignAlgo, SignHash, _, ClientSignAlgsCert) -> + do_check_cert_sign_algo(SignAlgo, SignHash, ClientSignAlgsCert). + + +%% DSA keys are not supported by TLS 1.3 +select_sign_algo(dsa, _ClientSignAlgs, _ServerSignAlgs) -> + {error, {insufficient_security, no_suitable_public_key}}; +%% TODO: Implement support for ECDSA keys! +select_sign_algo(_, [], _) -> + {error, {insufficient_security, no_suitable_signature_algorithm}}; +select_sign_algo(PublicKeyAlgo, [C|ClientSignAlgs], ServerSignAlgs) -> + {_, S, _} = ssl_cipher:scheme_to_components(C), + %% RSASSA-PKCS1-v1_5 and Legacy algorithms are not defined for use in signed + %% TLS handshake messages: filter sha-1 and rsa_pkcs1. + case ((PublicKeyAlgo =:= rsa andalso S =:= rsa_pss_rsae) + orelse (PublicKeyAlgo =:= rsa_pss andalso S =:= rsa_pss_rsae)) + andalso + lists:member(C, ServerSignAlgs) of + true -> + {ok, C}; + false -> + select_sign_algo(PublicKeyAlgo, ClientSignAlgs, ServerSignAlgs) + end. + + +do_check_cert_sign_algo(_, _, []) -> + {error, {insufficient_security, no_suitable_signature_algorithm}}; +do_check_cert_sign_algo(SignAlgo, SignHash, [Scheme|T]) -> + {Hash, Sign, _Curve} = ssl_cipher:scheme_to_components(Scheme), + case compare_sign_algos(SignAlgo, SignHash, Sign, Hash) of + true -> + ok; + _Else -> + do_check_cert_sign_algo(SignAlgo, SignHash, T) + end. + + +%% id-RSASSA-PSS (rsa_pss) indicates that the key may only be used for PSS signatures. +%% TODO: Uncomment when rsa_pss signatures are supported in certificates +%% compare_sign_algos(rsa_pss, Hash, Algo, Hash) +%% when Algo =:= rsa_pss_pss -> +%% true; +%% rsaEncryption (rsa) allows the key to be used for any of the standard encryption or +%% signature schemes. +compare_sign_algos(rsa, Hash, Algo, Hash) + when Algo =:= rsa_pss_rsae orelse + Algo =:= rsa_pkcs1 -> + true; +compare_sign_algos(Algo, Hash, Algo, Hash) -> + true; +compare_sign_algos(_, _, _, _) -> + false. + + +get_certificate_params(Cert) -> + {SignAlgo0, _Param, PublicKeyAlgo0} = ssl_handshake:get_cert_params(Cert), + {SignHash0, SignAlgo} = public_key:pkix_sign_types(SignAlgo0), + %% Convert hash to new format + SignHash = case SignHash0 of + sha -> + sha1; + H -> H + end, + PublicKeyAlgo = public_key_algo(PublicKeyAlgo0), + {PublicKeyAlgo, SignAlgo, SignHash}. + + +%% Note: copied from ssl_handshake +public_key_algo(?'id-RSASSA-PSS') -> + rsa_pss; +public_key_algo(?rsaEncryption) -> + rsa; +public_key_algo(?'id-ecPublicKey') -> + ecdsa; +public_key_algo(?'id-dsa') -> + dsa. + +get_signature_scheme_list(undefined) -> + undefined; +get_signature_scheme_list(#signature_algorithms_cert{ + signature_scheme_list = ClientSignatureSchemes}) -> + ClientSignatureSchemes; +get_signature_scheme_list(#signature_algorithms{ + signature_scheme_list = ClientSignatureSchemes}) -> + ClientSignatureSchemes. + +get_supported_groups(#supported_groups{supported_groups = Groups}) -> + Groups. + +get_key_shares(#key_share_client_hello{client_shares = ClientShares}) -> + ClientShares. + +maybe() -> + Ref = erlang:make_ref(), + Ok = fun(ok) -> ok; + ({ok,R}) -> R; + ({error,Reason}) -> + throw({Ref,Reason}) + end, + {Ref,Ok}. |