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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 | 1341 |
1 files changed, 1341 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..0efedf3400 --- /dev/null +++ b/lib/ssl/src/tls_handshake_1_3.erl @@ -0,0 +1,1341 @@ +%% +%% %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_connection.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]). + +%% Create handshake messages +-export([certificate/5, + certificate_verify/4, + encrypted_extensions/0, + server_hello/4]). + +-export([do_start/2, + do_negotiated/2, + do_wait_cert/2, + do_wait_cv/2, + do_wait_finished/2]). + +%%==================================================================== +%% Create handshake messages +%%==================================================================== + +server_hello(MsgType, SessionId, KeyShare, ConnectionStates) -> + #{security_parameters := SecParams} = + ssl_record:pending_connection_state(ConnectionStates, read), + Extensions = server_hello_extensions(MsgType, KeyShare), + #server_hello{server_version = {3,3}, %% legacy_version + cipher_suite = SecParams#security_parameters.cipher_suite, + compression_method = 0, %% legacy attribute + random = server_hello_random(MsgType, SecParams), + session_id = SessionId, + extensions = Extensions + }. + +server_hello_extensions(MsgType, KeyShare) -> + SupportedVersions = #server_hello_selected_version{selected_version = {3,4}}, + Extensions = #{server_hello_selected_version => SupportedVersions}, + ssl_handshake:add_server_share(MsgType, Extensions, KeyShare). + +server_hello_random(server_hello, #security_parameters{server_random = Random}) -> + Random; +%% For reasons of backward compatibility with middleboxes (see +%% Appendix D.4), the HelloRetryRequest message uses the same structure +%% as the ServerHello, but with Random set to the special value of the +%% SHA-256 of "HelloRetryRequest": +%% +%% CF 21 AD 74 E5 9A 61 11 BE 1D 8C 02 1E 65 B8 91 +%% C2 A2 11 16 7A BB 8C 5E 07 9E 09 E2 C8 A8 33 9C +server_hello_random(hello_retry_request, _) -> + crypto:hash(sha256, "HelloRetryRequest"). + + +%% TODO: implement support for encrypted_extensions +encrypted_extensions() -> + #encrypted_extensions{ + extensions = #{} + }. + + +certificate_request(SignAlgs0, SignAlgsCert0) -> + %% Input arguments contain TLS 1.2 algorithms due to backward compatibility + %% reasons. These {Hash, Algo} tuples must be filtered before creating the + %% the extensions. + SignAlgs = filter_tls13_algs(SignAlgs0), + SignAlgsCert = filter_tls13_algs(SignAlgsCert0), + Extensions0 = add_signature_algorithms(#{}, SignAlgs), + Extensions = add_signature_algorithms_cert(Extensions0, SignAlgsCert), + #certificate_request_1_3{ + certificate_request_context = <<>>, + extensions = Extensions}. + + +add_signature_algorithms(Extensions, SignAlgs) -> + Extensions#{signature_algorithms => + #signature_algorithms{signature_scheme_list = SignAlgs}}. + + +add_signature_algorithms_cert(Extensions, undefined) -> + Extensions; +add_signature_algorithms_cert(Extensions, SignAlgsCert) -> + Extensions#{signature_algorithms_cert => + #signature_algorithms{signature_scheme_list = SignAlgsCert}}. + + +filter_tls13_algs(undefined) -> undefined; +filter_tls13_algs(Algo) -> + lists:filter(fun is_atom/1, Algo). + + +%% TODO: use maybe monad for error handling! +%% enum { +%% X509(0), +%% RawPublicKey(2), +%% (255) +%% } CertificateType; +%% +%% struct { +%% select (certificate_type) { +%% case RawPublicKey: +%% /* From RFC 7250 ASN.1_subjectPublicKeyInfo */ +%% opaque ASN1_subjectPublicKeyInfo<1..2^24-1>; +%% +%% case X509: +%% opaque cert_data<1..2^24-1>; +%% }; +%% Extension extensions<0..2^16-1>; +%% } CertificateEntry; +%% +%% struct { +%% opaque certificate_request_context<0..2^8-1>; +%% CertificateEntry certificate_list<0..2^24-1>; +%% } Certificate; +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. + + +certificate_verify(PrivateKey, SignatureScheme, + #state{connection_states = ConnectionStates, + handshake_env = + #handshake_env{ + tls_handshake_history = {Messages, _}}}, server) -> + #{security_parameters := SecParamsR} = + ssl_record:pending_connection_state(ConnectionStates, write), + #security_parameters{prf_algorithm = HKDFAlgo} = SecParamsR, + + {HashAlgo, _, _} = + ssl_cipher:scheme_to_components(SignatureScheme), + + Context = lists:reverse(Messages), + + %% Transcript-Hash uses the HKDF hash function defined by the cipher suite. + THash = tls_v1:transcript_hash(Context, HKDFAlgo), + + %% Digital signatures use the hash function defined by the selected signature + %% scheme. + case sign(THash, <<"TLS 1.3, server CertificateVerify">>, + HashAlgo, PrivateKey) of + {ok, Signature} -> + {ok, #certificate_verify_1_3{ + algorithm = SignatureScheme, + signature = Signature + }}; + {error, badarg} -> + {error, badarg} + + end. + + +finished(#state{connection_states = ConnectionStates, + handshake_env = + #handshake_env{ + tls_handshake_history = {Messages, _}}}) -> + #{security_parameters := SecParamsR, + cipher_state := #cipher_state{finished_key = FinishedKey}} = + ssl_record:current_connection_state(ConnectionStates, write), + #security_parameters{prf_algorithm = HKDFAlgo} = SecParamsR, + + VerifyData = tls_v1:finished_verify_data(FinishedKey, HKDFAlgo, Messages), + + #finished{ + verify_data = VerifyData + }. + + +%%==================================================================== +%% 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(#certificate_verify_1_3{ + algorithm = Algorithm, + signature = Signature}) -> + EncAlgo = encode_algorithm(Algorithm), + EncSign = encode_signature(Signature), + {?CERTIFICATE_VERIFY, <<EncAlgo/binary, EncSign/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(?CERTIFICATE_VERIFY, <<?UINT16(EncAlgo), ?UINT16(Size), Signature:Size/binary>>) -> + Algorithm = ssl_cipher:signature_scheme(EncAlgo), + #certificate_verify_1_3{ + algorithm = Algorithm, + signature = Signature}; +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), + encode_cert_entries(Rest, + [<<?UINT24(DSize), Data/binary, BinExts/binary>> | Acc]). + +encode_algorithm(Algo) -> + Scheme = ssl_cipher:signature_scheme(Algo), + <<?UINT16(Scheme)>>. + +encode_signature(Signature) -> + Size = byte_size(Signature), + <<?UINT16(Size), Signature/binary>>. + +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 +sign(THash, Context, HashAlgo, PrivateKey) -> + Content = build_content(Context, THash), + + %% The length of the Salt MUST be equal to the length of the output + %% of the digest algorithm: rsa_pss_saltlen = -1 + try public_key:sign(Content, HashAlgo, PrivateKey, + [{rsa_padding, rsa_pkcs1_pss_padding}, + {rsa_pss_saltlen, -1}, + {rsa_mgf1_md, HashAlgo}]) of + Signature -> + {ok, Signature} + catch + error:badarg -> + {error, badarg} + end. + + +verify(THash, Context, HashAlgo, Signature, PublicKey) -> + Content = build_content(Context, THash), + + %% The length of the Salt MUST be equal to the length of the output + %% of the digest algorithm: rsa_pss_saltlen = -1 + try public_key:verify(Content, HashAlgo, Signature, PublicKey, + [{rsa_padding, rsa_pkcs1_pss_padding}, + {rsa_pss_saltlen, -1}, + {rsa_mgf1_md, HashAlgo}]) of + Result -> + {ok, Result} + catch + error:badarg -> + {error, badarg} + end. + + +build_content(Context, THash) -> + Prefix = binary:copy(<<32>>, 64), + <<Prefix/binary,Context/binary,?BYTE(0),THash/binary>>. + + +%%==================================================================== +%% Handle handshake messages +%%==================================================================== + + +do_start(#client_hello{cipher_suites = ClientCiphers, + session_id = SessionId, + extensions = Extensions} = _Hello, + #state{connection_states = _ConnectionStates0, + ssl_options = #ssl_options{ciphers = ServerCiphers, + signature_algs = ServerSignAlgs, + supported_groups = ServerGroups0}, + session = #session{own_certificate = Cert}} = State0) -> + + 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)), + Groups = Maybe(select_common_groups(ServerGroups, ClientGroups)), + Maybe(validate_key_share(ClientGroups, 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)), + + %% Select client public key. If no public key found in ClientShares or + %% ClientShares is empty, trigger HelloRetryRequest as we were able + %% to find an acceptable set of parameters but the ClientHello does not + %% contain sufficient information. + {Group, ClientPubKey} = get_client_public_key(Groups, ClientShares), + + %% Generate server_share + KeyShare = ssl_cipher:generate_server_share(Group), + + State1 = update_start_state(State0, Cipher, KeyShare, SessionId, + Group, SelectedSignAlg, ClientPubKey), + + %% 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. + Maybe(send_hello_retry_request(State1, ClientPubKey, KeyShare, 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, 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(start_handshake, + #state{connection_states = ConnectionStates0, + session = #session{session_id = SessionId, + own_certificate = OwnCert, + ecc = SelectedGroup, + sign_alg = SignatureScheme, + dh_public_value = ClientKey}, + ssl_options = #ssl_options{} = SslOpts, + key_share = KeyShare, + handshake_env = #handshake_env{tls_handshake_history = _HHistory0}, + connection_env = #connection_env{private_key = CertPrivateKey}, + static_env = #static_env{ + cert_db = CertDbHandle, + cert_db_ref = CertDbRef, + socket = _Socket, + transport_cb = _Transport} + } = State0) -> + {Ref,Maybe} = maybe(), + + try + %% Create server_hello + %% Extensions: supported_versions, key_share, (pre_shared_key) + ServerHello = server_hello(server_hello, SessionId, KeyShare, ConnectionStates0), + + {State1, _} = tls_connection:send_handshake(ServerHello, State0), + + State2 = + calculate_handshake_secrets(ClientKey, SelectedGroup, KeyShare, State1), + + State3 = ssl_record:step_encryption_state(State2), + + %% Create EncryptedExtensions + EncryptedExtensions = encrypted_extensions(), + + %% Encode EncryptedExtensions + State4 = tls_connection:queue_handshake(EncryptedExtensions, State3), + + %% Create and send CertificateRequest ({verify, verify_peer}) + {State5, NextState} = maybe_send_certificate_request(State4, SslOpts), + + %% Create Certificate + Certificate = certificate(OwnCert, CertDbHandle, CertDbRef, <<>>, server), + + %% Encode Certificate + State6 = tls_connection:queue_handshake(Certificate, State5), + + %% Create CertificateVerify + CertificateVerify = Maybe(certificate_verify(CertPrivateKey, SignatureScheme, + State6, server)), + %% Encode CertificateVerify + State7 = tls_connection:queue_handshake(CertificateVerify, State6), + + %% Create Finished + Finished = finished(State7), + + %% Encode Finished + State8 = tls_connection:queue_handshake(Finished, State7), + + %% Send first flight + {State9, _} = tls_connection:send_handshake_flight(State8), + + {State9, NextState} + + catch + {Ref, badarg} -> + ?ALERT_REC(?FATAL, ?INTERNAL_ERROR, {digitally_sign, badarg}) + end. + + +do_wait_cert(#certificate_1_3{} = Certificate, State0) -> + {Ref,Maybe} = maybe(), + try + Maybe(process_client_certificate(Certificate, State0)) + catch + {Ref, {certificate_required, State}} -> + {?ALERT_REC(?FATAL, ?CERTIFICATE_REQUIRED, certificate_required), State}; + {Ref, {{certificate_unknown, Reason}, State}} -> + {?ALERT_REC(?FATAL, ?CERTIFICATE_UNKNOWN, Reason), State}; + {Ref, {{internal_error, Reason}, State}} -> + {?ALERT_REC(?FATAL, ?INTERNAL_ERROR, Reason), State}; + {Ref, {{handshake_failure, Reason}, State}} -> + {?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, Reason), State}; + {#alert{} = Alert, State} -> + {Alert, State} + end. + + +do_wait_cv(#certificate_verify_1_3{} = CertificateVerify, State0) -> + {Ref,Maybe} = maybe(), + try + Maybe(verify_signature_algorithm(State0, CertificateVerify)), + Maybe(verify_certificate_verify(State0, CertificateVerify)) + catch + {Ref, {{bad_certificate, Reason}, State}} -> + {?ALERT_REC(?FATAL, ?BAD_CERTIFICATE, {bad_certificate, Reason}), State}; + {Ref, {badarg, State}} -> + {?ALERT_REC(?FATAL, ?INTERNAL_ERROR, {verify, badarg}), State}; + {Ref, {{handshake_failure, Reason}, State}} -> + {?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, {handshake_failure, Reason}), State} + end. + + +do_wait_finished(#finished{verify_data = VerifyData}, + #state{connection_states = _ConnectionStates0, + session = #session{session_id = _SessionId, + own_certificate = _OwnCert}, + ssl_options = #ssl_options{} = _SslOpts, + key_share = _KeyShare, + handshake_env = #handshake_env{tls_handshake_history = _HHistory0}, + static_env = #static_env{ + cert_db = _CertDbHandle, + cert_db_ref = _CertDbRef, + socket = _Socket, + transport_cb = _Transport} + } = State0) -> + + {Ref,Maybe} = maybe(), + + try + Maybe(validate_client_finished(State0, VerifyData)), + + State1 = calculate_traffic_secrets(State0), + + %% Configure traffic keys + ssl_record:step_encryption_state(State1) + + + catch + {Ref, decrypt_error} -> + ?ALERT_REC(?FATAL, ?DECRYPT_ERROR, decrypt_error) + end. + + +%% TODO: Remove this function! +%% not_implemented(State, Reason) -> +%% {error, {not_implemented, State, Reason}}. +%% +%% not_implemented(update_secrets, State0, Reason) -> +%% State1 = calculate_traffic_secrets(State0), +%% State = ssl_record:step_encryption_state(State1), +%% {error, {not_implemented, State, Reason}}. + + + +%% Recipients of Finished messages MUST verify that the contents are +%% correct and if incorrect MUST terminate the connection with a +%% "decrypt_error" alert. +validate_client_finished(#state{connection_states = ConnectionStates, + handshake_env = + #handshake_env{ + tls_handshake_history = {Messages0, _}}}, VerifyData) -> + #{security_parameters := SecParamsR, + cipher_state := #cipher_state{finished_key = FinishedKey}} = + ssl_record:current_connection_state(ConnectionStates, read), + #security_parameters{prf_algorithm = HKDFAlgo} = SecParamsR, + + %% Drop the client's finished message, it is not part of the handshake context + %% when the client calculates its finished message. + [_|Messages] = Messages0, + + ControlData = tls_v1:finished_verify_data(FinishedKey, HKDFAlgo, Messages), + compare_verify_data(ControlData, VerifyData). + + +compare_verify_data(Data, Data) -> + ok; +compare_verify_data(_, _) -> + {error, decrypt_error}. + + +send_hello_retry_request(#state{connection_states = ConnectionStates0} = State0, + no_suitable_key, KeyShare, SessionId) -> + ServerHello = server_hello(hello_retry_request, SessionId, KeyShare, ConnectionStates0), + {State1, _} = tls_connection:send_handshake(ServerHello, State0), + + %% TODO: Fix handshake history! + State2 = replace_ch1_with_message_hash(State1), + + {ok, {State2, start}}; +send_hello_retry_request(State0, _, _, _) -> + %% Suitable key found. + {ok, {State0, negotiated}}. + + +maybe_send_certificate_request(State, #ssl_options{verify = verify_none}) -> + {State, wait_finished}; +maybe_send_certificate_request(State, #ssl_options{ + verify = verify_peer, + signature_algs = SignAlgs, + signature_algs_cert = SignAlgsCert}) -> + CertificateRequest = certificate_request(SignAlgs, SignAlgsCert), + {tls_connection:queue_handshake(CertificateRequest, State), wait_cert}. + + +process_client_certificate(#certificate_1_3{ + certificate_request_context = <<>>, + certificate_list = []}, + #state{ssl_options = + #ssl_options{ + fail_if_no_peer_cert = false}} = State) -> + {ok, {State, wait_finished}}; +process_client_certificate(#certificate_1_3{ + certificate_request_context = <<>>, + certificate_list = []}, + #state{ssl_options = + #ssl_options{ + fail_if_no_peer_cert = true}} = State0) -> + + %% At this point the client believes that the connection is up and starts using + %% its traffic secrets. In order to be able send an proper Alert to the client + %% the server should also change its connection state and use the traffic + %% secrets. + State1 = calculate_traffic_secrets(State0), + State = ssl_record:step_encryption_state(State1), + {error, {certificate_required, State}}; +process_client_certificate(#certificate_1_3{certificate_list = Certs0}, + #state{ssl_options = + #ssl_options{signature_algs = SignAlgs, + signature_algs_cert = SignAlgsCert} = SslOptions, + static_env = + #static_env{ + role = Role, + host = Host, + cert_db = CertDbHandle, + cert_db_ref = CertDbRef, + crl_db = CRLDbHandle}} = State0) -> + %% TODO: handle extensions! + + %% Remove extensions from list of certificates! + Certs = convert_certificate_chain(Certs0), + case is_supported_signature_algorithm(Certs, SignAlgs, SignAlgsCert) of + true -> + case validate_certificate_chain(Certs, CertDbHandle, CertDbRef, + SslOptions, CRLDbHandle, Role, Host) of + {ok, {PeerCert, PublicKeyInfo}} -> + State = store_peer_cert(State0, PeerCert, PublicKeyInfo), + {ok, {State, wait_cv}}; + {error, Reason} -> + State1 = calculate_traffic_secrets(State0), + State = ssl_record:step_encryption_state(State1), + {error, {Reason, State}}; + #alert{} = Alert -> + State1 = calculate_traffic_secrets(State0), + State = ssl_record:step_encryption_state(State1), + {Alert, State} + end; + false -> + State1 = calculate_traffic_secrets(State0), + State = ssl_record:step_encryption_state(State1), + {error, {{handshake_failure, + "Client certificate uses unsupported signature algorithm"}, State}} + end. + + +%% TODO: check whole chain! +is_supported_signature_algorithm(Certs, SignAlgs, undefined) -> + is_supported_signature_algorithm(Certs, SignAlgs); +is_supported_signature_algorithm(Certs, _, SignAlgsCert) -> + is_supported_signature_algorithm(Certs, SignAlgsCert). +%% +is_supported_signature_algorithm([BinCert|_], SignAlgs0) -> + #'OTPCertificate'{signatureAlgorithm = SignAlg} = + public_key:pkix_decode_cert(BinCert, otp), + SignAlgs = filter_tls13_algs(SignAlgs0), + Scheme = ssl_cipher:signature_algorithm_to_scheme(SignAlg), + lists:member(Scheme, SignAlgs). + + +validate_certificate_chain(Certs, CertDbHandle, CertDbRef, SslOptions, CRLDbHandle, Role, Host) -> + ServerName = ssl_handshake:server_name(SslOptions#ssl_options.server_name_indication, Host, Role), + [PeerCert | ChainCerts ] = Certs, + try + {TrustedCert, CertPath} = + ssl_certificate:trusted_cert_and_path(Certs, CertDbHandle, CertDbRef, + SslOptions#ssl_options.partial_chain), + ValidationFunAndState = + ssl_handshake:validation_fun_and_state(SslOptions#ssl_options.verify_fun, Role, + CertDbHandle, CertDbRef, ServerName, + SslOptions#ssl_options.customize_hostname_check, + SslOptions#ssl_options.crl_check, CRLDbHandle, CertPath), + Options = [{max_path_length, SslOptions#ssl_options.depth}, + {verify_fun, ValidationFunAndState}], + %% TODO: Validate if Certificate is using a supported signature algorithm + %% (signature_algs_cert)! + case public_key:pkix_path_validation(TrustedCert, CertPath, Options) of + {ok, {PublicKeyInfo,_}} -> + {ok, {PeerCert, PublicKeyInfo}}; + {error, Reason} -> + ssl_handshake:handle_path_validation_error(Reason, PeerCert, ChainCerts, + SslOptions, Options, + CertDbHandle, CertDbRef) + end + catch + error:{badmatch,{asn1, Asn1Reason}} -> + %% ASN-1 decode of certificate somehow failed + {error, {certificate_unknown, {failed_to_decode_certificate, Asn1Reason}}}; + error:OtherReason -> + {error, {internal_error, {unexpected_error, OtherReason}}} + end. + + +store_peer_cert(#state{session = Session, + handshake_env = HsEnv} = State, PeerCert, PublicKeyInfo) -> + State#state{session = Session#session{peer_certificate = PeerCert}, + handshake_env = HsEnv#handshake_env{public_key_info = PublicKeyInfo}}. + + +convert_certificate_chain(Certs) -> + Fun = fun(#certificate_entry{data = Data}) -> + {true, Data}; + (_) -> + false + end, + lists:filtermap(Fun, Certs). + + +%% 4.4.1. The Transcript Hash +%% +%% As an exception to this general rule, when the server responds to a +%% ClientHello with a HelloRetryRequest, the value of ClientHello1 is +%% replaced with a special synthetic handshake message of handshake type +%% "message_hash" containing Hash(ClientHello1). I.e., +%% +%% Transcript-Hash(ClientHello1, HelloRetryRequest, ... Mn) = +%% Hash(message_hash || /* Handshake type */ +%% 00 00 Hash.length || /* Handshake message length (bytes) */ +%% Hash(ClientHello1) || /* Hash of ClientHello1 */ +%% HelloRetryRequest || ... || Mn) +%% +%% NOTE: Hash.length is used in practice (openssl) and not message length! +%% It is most probably a fault in the RFC. +replace_ch1_with_message_hash(#state{connection_states = ConnectionStates, + handshake_env = + #handshake_env{ + tls_handshake_history = + {[HRR,CH1|HHistory], LM}} = HSEnv} = State0) -> + #{security_parameters := SecParamsR} = + ssl_record:pending_connection_state(ConnectionStates, read), + #security_parameters{prf_algorithm = HKDFAlgo} = SecParamsR, + MessageHash = message_hash(CH1, HKDFAlgo), + State0#state{handshake_env = + HSEnv#handshake_env{ + tls_handshake_history = + {[HRR,MessageHash|HHistory], LM}}}. + + +message_hash(ClientHello1, HKDFAlgo) -> + [?MESSAGE_HASH, + 0,0,ssl_cipher:hash_size(HKDFAlgo), + crypto:hash(HKDFAlgo, ClientHello1)]. + + +calculate_handshake_secrets(ClientKey, SelectedGroup, KeyShare, + #state{connection_states = ConnectionStates, + handshake_env = + #handshake_env{ + tls_handshake_history = HHistory}} = State0) -> + #{security_parameters := SecParamsR} = + ssl_record:pending_connection_state(ConnectionStates, read), + #security_parameters{prf_algorithm = HKDFAlgo, + cipher_suite = CipherSuite} = SecParamsR, + + %% Calculate handshake_secret + PSK = binary:copy(<<0>>, ssl_cipher:hash_size(HKDFAlgo)), + EarlySecret = tls_v1:key_schedule(early_secret, HKDFAlgo , {psk, 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), + + %% Calculate Finished Keys + ReadFinishedKey = tls_v1:finished_key(ClientHSTrafficSecret, HKDFAlgo), + WriteFinishedKey = tls_v1:finished_key(ServerHSTrafficSecret, HKDFAlgo), + + update_pending_connection_states(State0, HandshakeSecret, + ReadKey, ReadIV, ReadFinishedKey, + WriteKey, WriteIV, WriteFinishedKey). + +calculate_traffic_secrets(#state{connection_states = ConnectionStates, + handshake_env = + #handshake_env{ + tls_handshake_history = HHistory}} = State0) -> + #{security_parameters := SecParamsR} = + ssl_record:pending_connection_state(ConnectionStates, read), + #security_parameters{prf_algorithm = HKDFAlgo, + cipher_suite = CipherSuite, + master_secret = HandshakeSecret} = SecParamsR, + + MasterSecret = + tls_v1:key_schedule(master_secret, HKDFAlgo, HandshakeSecret), + + %% Get the correct list messages for the handshake context. + Messages = get_handshake_context(HHistory), + + %% Calculate [sender]_application_traffic_secret_0 + ClientAppTrafficSecret0 = + tls_v1:client_application_traffic_secret_0(HKDFAlgo, MasterSecret, lists:reverse(Messages)), + ServerAppTrafficSecret0 = + tls_v1:server_application_traffic_secret_0(HKDFAlgo, MasterSecret, lists:reverse(Messages)), + + %% Calculate traffic keys + #{cipher := Cipher} = ssl_cipher_format:suite_definition(CipherSuite), + {ReadKey, ReadIV} = tls_v1:calculate_traffic_keys(HKDFAlgo, Cipher, ClientAppTrafficSecret0), + {WriteKey, WriteIV} = tls_v1:calculate_traffic_keys(HKDFAlgo, Cipher, ServerAppTrafficSecret0), + + update_pending_connection_states(State0, MasterSecret, + ReadKey, ReadIV, undefined, + WriteKey, WriteIV, undefined). + + +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. + +%% TODO: implement EC keys +get_public_key({?'rsaEncryption', PublicKey, _}) -> + PublicKey. + + +%% 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(#state{connection_states = + CS = #{pending_read := PendingRead0, + pending_write := PendingWrite0}} = State, + HandshakeSecret, + ReadKey, ReadIV, ReadFinishedKey, + WriteKey, WriteIV, WriteFinishedKey) -> + PendingRead = update_connection_state(PendingRead0, HandshakeSecret, + ReadKey, ReadIV, ReadFinishedKey), + PendingWrite = update_connection_state(PendingWrite0, HandshakeSecret, + WriteKey, WriteIV, WriteFinishedKey), + State#state{connection_states = CS#{pending_read => PendingRead, + pending_write => PendingWrite}}. + +update_connection_state(ConnectionState = #{security_parameters := SecurityParameters0}, + HandshakeSecret, Key, IV, FinishedKey) -> + %% Store secret + SecurityParameters = SecurityParameters0#security_parameters{ + master_secret = HandshakeSecret}, + ConnectionState#{security_parameters => SecurityParameters, + cipher_state => cipher_init(Key, IV, FinishedKey)}. + + +update_start_state(#state{connection_states = ConnectionStates0, + connection_env = CEnv, + session = Session} = State, + Cipher, KeyShare, SessionId, + Group, SelectedSignAlg, ClientPubKey) -> + #{security_parameters := SecParamsR0} = PendingRead = + maps:get(pending_read, ConnectionStates0), + #{security_parameters := SecParamsW0} = PendingWrite = + maps:get(pending_write, ConnectionStates0), + SecParamsR = ssl_cipher:security_parameters_1_3(SecParamsR0, Cipher), + SecParamsW = ssl_cipher:security_parameters_1_3(SecParamsW0, Cipher), + ConnectionStates = + ConnectionStates0#{pending_read => PendingRead#{security_parameters => SecParamsR}, + pending_write => PendingWrite#{security_parameters => SecParamsW}}, + State#state{connection_states = ConnectionStates, + key_share = KeyShare, + session = Session#session{session_id = SessionId, + ecc = Group, + sign_alg = SelectedSignAlg, + dh_public_value = ClientPubKey, + cipher_suite = Cipher}, + connection_env = CEnv#connection_env{negotiated_version = {3,4}}}. + + +cipher_init(Key, IV, FinishedKey) -> + #cipher_state{key = Key, + iv = IV, + finished_key = FinishedKey, + tag_len = 16}. + + +%% Get handshake context for verification of CertificateVerify. +%% +%% Verify CertificateVerify: +%% ClientHello (client) (1) +%% ServerHello (server) (2) +%% EncryptedExtensions (server) (8) +%% CertificateRequest (server) (13) +%% Certificate (server) (11) +%% CertificateVerify (server) (15) +%% Finished (server) (20) +%% Certificate (client) (11) +%% CertificateVerify (client) (15) - Drop! Not included in calculations! +get_handshake_context_cv({[<<15,_/binary>>|Messages], _}) -> + Messages. + + +%% Get handshake context for traffic key calculation. +%% +%% Client is authenticated with certificate: +%% ClientHello (client) (1) +%% ServerHello (server) (2) +%% EncryptedExtensions (server) (8) +%% CertificateRequest (server) (13) +%% Certificate (server) (11) +%% CertificateVerify (server) (15) +%% Finished (server) (20) +%% Certificate (client) (11) - Drop! Not included in calculations! +%% CertificateVerify (client) (15) - Drop! Not included in calculations! +%% Finished (client) (20) - Drop! Not included in calculations! +%% +%% Client is authenticated but sends empty certificate: +%% ClientHello (client) (1) +%% ServerHello (server) (2) +%% EncryptedExtensions (server) (8) +%% CertificateRequest (server) (13) +%% Certificate (server) (11) +%% CertificateVerify (server) (15) +%% Finished (server) (20) +%% Certificate (client) (11) - Drop! Not included in calculations! +%% Finished (client) (20) - Drop! Not included in calculations! +%% +%% Client is not authenticated: +%% ClientHello (client) (1) +%% ServerHello (server) (2) +%% EncryptedExtensions (server) (8) +%% Certificate (server) (11) +%% CertificateVerify (server) (15) +%% Finished (server) (20) +%% Finished (client) (20) - Drop! Not included in calculations! +%% +%% Drop all client messages from the front of the iolist using the property that +%% incoming messages are binaries. +get_handshake_context({Messages, _}) -> + get_handshake_context(Messages); +get_handshake_context([H|T]) when is_binary(H) -> + get_handshake_context(T); +get_handshake_context(L) -> + L. + + +%% If sent by a client, the signature algorithm used in the signature +%% MUST be one of those present in the supported_signature_algorithms +%% field of the "signature_algorithms" extension in the +%% CertificateRequest message. +verify_signature_algorithm(#state{ssl_options = + #ssl_options{ + signature_algs = ServerSignAlgs}} = State0, + #certificate_verify_1_3{algorithm = ClientSignAlg}) -> + case lists:member(ClientSignAlg, ServerSignAlgs) of + true -> + ok; + false -> + State1 = calculate_traffic_secrets(State0), + State = ssl_record:step_encryption_state(State1), + {error, {{handshake_failure, + "CertificateVerify uses unsupported signature algorithm"}, State}} + end. + + +verify_certificate_verify(#state{connection_states = ConnectionStates, + handshake_env = + #handshake_env{ + public_key_info = PublicKeyInfo, + tls_handshake_history = HHistory}} = State0, + #certificate_verify_1_3{ + algorithm = SignatureScheme, + signature = Signature}) -> + #{security_parameters := SecParamsR} = + ssl_record:pending_connection_state(ConnectionStates, write), + #security_parameters{prf_algorithm = HKDFAlgo} = SecParamsR, + + {HashAlgo, _, _} = + ssl_cipher:scheme_to_components(SignatureScheme), + + Messages = get_handshake_context_cv(HHistory), + + Context = lists:reverse(Messages), + + %% Transcript-Hash uses the HKDF hash function defined by the cipher suite. + THash = tls_v1:transcript_hash(Context, HKDFAlgo), + + PublicKey = get_public_key(PublicKeyInfo), + + %% Digital signatures use the hash function defined by the selected signature + %% scheme. + case verify(THash, <<"TLS 1.3, client CertificateVerify">>, + HashAlgo, Signature, PublicKey) of + {ok, true} -> + {ok, {State0, wait_finished}}; + {ok, false} -> + State1 = calculate_traffic_secrets(State0), + State = ssl_record:step_encryption_state(State1), + {error, {{handshake_failure, "Failed to verify CertificateVerify"}, State}}; + {error, badarg} -> + State1 = calculate_traffic_secrets(State0), + State = ssl_record:step_encryption_state(State1), + {error, {badarg, State}} + end. + + +%% 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_common_groups(_, []) -> + {error, {insufficient_security, no_suitable_groups}}; +select_common_groups(ServerGroups, ClientGroups) -> + Fun = fun(E) -> lists:member(E, ClientGroups) end, + case lists:filter(Fun, ServerGroups) of + [] -> + {error, {insufficient_security, no_suitable_groups}}; + L -> + {ok, L} + 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|_] = Groups, ClientShares) -> + get_client_public_key(Groups, ClientShares, Group). +%% +get_client_public_key(_, [], PreferredGroup) -> + {PreferredGroup, no_suitable_key}; +get_client_public_key([], _, PreferredGroup) -> + {PreferredGroup, no_suitable_key}; +get_client_public_key([Group|Groups], ClientShares, PreferredGroup) -> + case lists:keysearch(Group, 2, ClientShares) of + {value, {_, _, ClientPublicKey}} -> + {Group, ClientPublicKey}; + false -> + get_client_public_key(Groups, ClientShares, PreferredGroup) + end. + + +%% get_client_public_key(Group, ClientShares) -> +%% case lists:keysearch(Group, 2, ClientShares) of +%% {value, {_, _, ClientPublicKey}} -> +%% 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. +%% no_suitable_key +%% 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}. |