diff options
Diffstat (limited to 'lib/ssl/src/tls_handshake_1_3.erl')
| -rw-r--r-- | lib/ssl/src/tls_handshake_1_3.erl | 344 |
1 files changed, 297 insertions, 47 deletions
diff --git a/lib/ssl/src/tls_handshake_1_3.erl b/lib/ssl/src/tls_handshake_1_3.erl index 104017b67c..f381e038cf 100644 --- a/lib/ssl/src/tls_handshake_1_3.erl +++ b/lib/ssl/src/tls_handshake_1_3.erl @@ -28,13 +28,45 @@ -include("tls_handshake_1_3.hrl"). -include("ssl_alert.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/5]). +-export([handle_client_hello/3]). + +%% Create handshake messages +-export([server_hello/4]). + +%%==================================================================== +%% 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 = + SecParams#security_parameters.compression_algorithm, + 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). + + + +%%==================================================================== +%% Encode handshake +%%==================================================================== encode_handshake(#certificate_request_1_3{ certificate_request_context = Context, @@ -68,14 +100,19 @@ encode_handshake(#key_update{request_update = 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), + 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), + Exts = decode_extensions(EncExts, certificate_request), #certificate_request_1_3{ certificate_request_context = Context, extensions = Exts}; @@ -94,12 +131,12 @@ decode_handshake(?CERTIFICATE, <<?BYTE(CSize), Context:CSize/binary, }; decode_handshake(?ENCRYPTED_EXTENSIONS, <<?UINT16(Size), EncExts:Size/binary>>) -> #encrypted_extensions{ - extensions = decode_extensions(EncExts) + 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), + Exts = decode_extensions(BinExts, encrypted_extensions), #new_session_ticket{ticket_lifetime = LifeTime, ticket_age_add = Age, ticket_nonce = Nonce, @@ -143,58 +180,271 @@ 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), + 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) -> - ssl_handshake:decode_extensions(Exts, {3,4}). +decode_extensions(Exts, MessageType) -> + ssl_handshake:decode_extensions(Exts, {3,4}, MessageType). extensions_list(HelloExtensions) -> [Ext || {_, Ext} <- maps:to_list(HelloExtensions)]. -handle_client_hello(Version, - #client_hello{session_id = SugesstedId, - cipher_suites = CipherSuites, - compression_methods = Compressions, +%%==================================================================== +%% Handle handshake messages +%%==================================================================== + +handle_client_hello(#client_hello{cipher_suites = ClientCiphers, random = Random, - extensions = HelloExt}, - #ssl_options{versions = Versions, - signature_algs = SupportedHashSigns, - eccs = SupportedECCs, - honor_ecc_order = ECCOrder} = SslOpts, - {Port, Session0, Cache, CacheCb, ConnectionStates0, Cert, _}, - Renegotiation) -> - case tls_record:is_acceptable_version(Version, Versions) of - true -> - %% Get supported_groups - %% SupportedGroups = maps:get(elliptic_curves, HelloExt, undefined), - %% Get KeyShareClientHello - - %% Validate supported_groups + KeyShareClientHello - %% IF valid THEN - %% IF supported_groups IS empty send HelloRetryRequest - %% ELSE continue - %% ELSE - %% send Alert - %% ClientHashSigns = maps:get(signature_algs, HelloExt, undefined), - %% ClientSignatureSchemes = maps:get(signature_algs_cert, HelloExt, undefined), - - %% Implement session handling. - - %% Select curve - - %% Sessions cannot be resumed by ClientHello - - %% Select cipher_suite - %% Select hash_sign - - %% Handle extensions - ok; - false -> - ?ALERT_REC(?FATAL, ?PROTOCOL_VERSION) + 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)), + + %% Handle certificate + {PublicKeyAlgo, SignAlgo} = get_certificate_params(Cert), + + %% Check if client supports signature algorithm of server certificate + Maybe(check_cert_sign_algo(SignAlgo, ClientSignAlgs, ClientSignAlgsCert)), + + %% Check if server supports + 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, + client_random => Random, + 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, {client_hello_retry_request, _Group0}} -> + %% TODO + exit({client_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. + + +%% 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 -> + %% ClientHelloRetryRequest + {error, {client_hello_retry_request, Group}} + end. + +select_cipher_suite([], _) -> + {error, no_suitable_cipher}; +select_cipher_suite([Cipher|ClientCiphers], ServerCiphers) -> + case 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_cert_sign_algo(SignAlgo, ClientSignAlgs, undefined) -> + maybe_lists_member(SignAlgo, ClientSignAlgs, + {insufficient_security, no_suitable_signature_algorithm}); +check_cert_sign_algo(SignAlgo, _, ClientSignAlgsCert) -> + maybe_lists_member(SignAlgo, ClientSignAlgsCert, + {insufficient_security, no_suitable_signature_algorithm}). + + +%% DSA keys are not supported by TLS 1.3 +select_sign_algo(dsa, _ClientSignAlgs, _ServerSignAlgs) -> + {error, {insufficient_security, no_suitable_public_key}}; +%% TODO: Implement check for ellipctic curves! +select_sign_algo(PublicKeyAlgo, [C|ClientSignAlgs], ServerSignAlgs) -> + {_, S, _} = ssl_cipher:scheme_to_components(C), + case PublicKeyAlgo =:= rsa andalso + ((S =:= rsa_pkcs1) orelse (S =:= rsa_pss_rsae) orelse (S =:= rsa_pss_pss)) andalso + lists:member(C, ServerSignAlgs) of + true -> + {ok, C}; + false -> + select_sign_algo(PublicKeyAlgo, ClientSignAlgs, ServerSignAlgs) + end. + + +maybe_lists_member(Elem, List, Error) -> + case lists:member(Elem, List) of + true -> + ok; + false -> + {error, Error} + end. + +%% TODO: test with ecdsa, rsa_pss_rsae, rsa_pss_pss +get_certificate_params(Cert) -> + {SignAlgo0, _Param, PublicKeyAlgo0} = ssl_handshake:get_cert_params(Cert), + SignAlgo = public_key:pkix_sign_types(SignAlgo0), + PublicKeyAlgo = public_key_algo(PublicKeyAlgo0), + Scheme = sign_algo_to_scheme(SignAlgo), + {PublicKeyAlgo, Scheme}. + +sign_algo_to_scheme({Hash0, Sign0}) -> + SupportedSchemes = tls_v1:default_signature_schemes({3,4}), + Hash = case Hash0 of + sha -> + sha1; + H -> + H + end, + Sign = case Sign0 of + rsa -> + rsa_pkcs1; + S -> + S + end, + sign_algo_to_scheme(Hash, Sign, SupportedSchemes). +%% +sign_algo_to_scheme(_, _, []) -> + not_found; +sign_algo_to_scheme(H, S, [Scheme|T]) -> + {Hash, Sign, _Curve} = ssl_cipher:scheme_to_components(Scheme), + case H =:= Hash andalso S =:= Sign of + true -> + Scheme; + false -> + sign_algo_to_scheme(H, S, T) + end. + + +%% Note: copied from ssl_handshake +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}. |