%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2013-2018. 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 SSL-handshake protocol (common
%% to SSL/TLS and DTLS
%%----------------------------------------------------------------------
-module(ssl_handshake).
-include("ssl_handshake.hrl").
-include("ssl_record.hrl").
-include("ssl_cipher.hrl").
-include("ssl_alert.hrl").
-include("ssl_internal.hrl").
-include("ssl_srp.hrl").
-include_lib("public_key/include/public_key.hrl").
-export_type([ssl_handshake/0, ssl_handshake_history/0,
public_key_info/0, oid/0]).
-type oid() :: tuple().
-type public_key_params() :: #'Dss-Parms'{} | {namedCurve, oid()} | #'ECParameters'{} | term().
-type public_key_info() :: {oid(), #'RSAPublicKey'{} | integer() | #'ECPoint'{}, public_key_params()}.
-type ssl_handshake_history() :: {[binary()], [binary()]}.
-type ssl_handshake() :: #server_hello{} | #server_hello_done{} | #certificate{} | #certificate_request{} |
#client_key_exchange{} | #finished{} | #certificate_verify{} |
#hello_request{} | #next_protocol{}.
%% Create handshake messages
-export([hello_request/0, server_hello/4, server_hello_done/0,
certificate/4, client_certificate_verify/6, certificate_request/5, key_exchange/3,
finished/5, next_protocol/1]).
%% Handle handshake messages
-export([certify/7, certificate_verify/6, verify_signature/5,
master_secret/4, server_key_exchange_hash/2, verify_connection/6,
init_handshake_history/0, update_handshake_history/2, verify_server_key/5,
select_version/3, select_supported_version/2, extension_value/1
]).
%% Encode
-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_vector/1, decode_hello_extensions/3, decode_extensions/1,
decode_server_key/3, decode_client_key/3,
decode_suites/2
]).
%% Cipher suites handling
-export([available_suites/2, available_signature_algs/2, available_signature_algs/4,
cipher_suites/3, prf/6, select_session/11, supported_ecc/1,
premaster_secret/2, premaster_secret/3, premaster_secret/4]).
%% Extensions handling
-export([client_hello_extensions/5,
handle_client_hello_extensions/9, %% Returns server hello extensions
handle_server_hello_extensions/9, select_curve/2, select_curve/3,
select_hashsign/4, select_hashsign/5,
select_hashsign_algs/3
]).
%%====================================================================
%% Create handshake messages
%%====================================================================
%%--------------------------------------------------------------------
-spec hello_request() -> #hello_request{}.
%%
%% Description: Creates a hello request message sent by server to
%% trigger renegotiation.
%%--------------------------------------------------------------------
hello_request() ->
#hello_request{}.
%%--------------------------------------------------------------------
-spec server_hello(#session{}, ssl_record:ssl_version(), ssl_record:connection_states(),
Extension::map()) -> #server_hello{}.
%%
%% Description: Creates a server hello message.
%%--------------------------------------------------------------------
server_hello(SessionId, Version, ConnectionStates, Extensions) ->
#{security_parameters := SecParams} =
ssl_record:pending_connection_state(ConnectionStates, read),
#server_hello{server_version = 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
}.
%%--------------------------------------------------------------------
-spec server_hello_done() -> #server_hello_done{}.
%%
%% Description: Creates a server hello done message.
%%--------------------------------------------------------------------
server_hello_done() ->
#server_hello_done{}.
%%--------------------------------------------------------------------
-spec certificate(der_cert(), db_handle(), certdb_ref(), client | server) -> #certificate{} | #alert{}.
%%
%% Description: Creates a certificate message.
%%--------------------------------------------------------------------
certificate(OwnCert, CertDbHandle, CertDbRef, client) ->
Chain =
case ssl_certificate:certificate_chain(OwnCert, CertDbHandle, CertDbRef) of
{ok, _, CertChain} ->
CertChain;
{error, _} ->
%% If no suitable certificate is available, the client
%% SHOULD send a certificate message containing no
%% certificates. (chapter 7.4.6. RFC 4346)
[]
end,
#certificate{asn1_certificates = Chain};
certificate(OwnCert, CertDbHandle, CertDbRef, server) ->
case ssl_certificate:certificate_chain(OwnCert, CertDbHandle, CertDbRef) of
{ok, _, Chain} ->
#certificate{asn1_certificates = Chain};
{error, Error} ->
?ALERT_REC(?FATAL, ?INTERNAL_ERROR, {server_has_no_suitable_certificates, Error})
end.
%%--------------------------------------------------------------------
-spec client_certificate_verify(undefined | der_cert(), binary(),
ssl_record:ssl_version(), term(), public_key:private_key(),
ssl_handshake_history()) ->
#certificate_verify{} | ignore | #alert{}.
%%
%% Description: Creates a certificate_verify message, called by the client.
%%--------------------------------------------------------------------
client_certificate_verify(undefined, _, _, _, _, _) ->
ignore;
client_certificate_verify(_, _, _, _, undefined, _) ->
ignore;
client_certificate_verify(OwnCert, MasterSecret, Version,
{HashAlgo, SignAlgo},
PrivateKey, {Handshake, _}) ->
case public_key:pkix_is_fixed_dh_cert(OwnCert) of
true ->
?ALERT_REC(?FATAL, ?UNSUPPORTED_CERTIFICATE, fixed_diffie_hellman_prohibited);
false ->
Hashes =
calc_certificate_verify(Version, HashAlgo, MasterSecret, Handshake),
Signed = digitally_signed(Version, Hashes, HashAlgo, PrivateKey),
#certificate_verify{signature = Signed, hashsign_algorithm = {HashAlgo, SignAlgo}}
end.
%%--------------------------------------------------------------------
-spec certificate_request(ssl_cipher_format:cipher_suite(), db_handle(),
certdb_ref(), #hash_sign_algos{}, ssl_record:ssl_version()) ->
#certificate_request{}.
%%
%% Description: Creates a certificate_request message, called by the server.
%%--------------------------------------------------------------------
certificate_request(CipherSuite, CertDbHandle, CertDbRef, HashSigns, Version) ->
Types = certificate_types(ssl_cipher_format:suite_definition(CipherSuite), Version),
Authorities = certificate_authorities(CertDbHandle, CertDbRef),
#certificate_request{
certificate_types = Types,
hashsign_algorithms = HashSigns,
certificate_authorities = Authorities
}.
%%--------------------------------------------------------------------
-spec key_exchange(client | server, ssl_record:ssl_version(),
{premaster_secret, binary(), public_key_info()} |
{dh, binary()} |
{dh, {binary(), binary()}, #'DHParameter'{}, {HashAlgo::atom(), SignAlgo::atom()},
binary(), binary(), public_key:private_key()} |
{ecdh, _, _, _, _, _} |
{ecdh, #'ECPrivateKey'{}} |
{psk, _, _, _, _, _} |
{psk, binary()} |
{dhe_psk, _, _, _, _, _, _, _} |
{dhe_psk, binary(), binary()} |
{ecdhe_psk, _, _, _, _, _, _} |
{ecdhe_psk, binary(), #'ECPrivateKey'{}} |
{srp, {binary(), binary()}, #srp_user{}, {HashAlgo::atom(), SignAlgo::atom()},
binary(), binary(), public_key:private_key()} |
{srp, _} |
{psk_premaster_secret, _, _, _}) ->
#client_key_exchange{} | #server_key_exchange{}.
%%
%% Description: Creates a keyexchange message.
%%--------------------------------------------------------------------
key_exchange(client, _Version, {premaster_secret, Secret, {_, PublicKey, _}}) ->
EncPremasterSecret =
encrypted_premaster_secret(Secret, PublicKey),
#client_key_exchange{exchange_keys = EncPremasterSecret};
key_exchange(client, _Version, {dh, PublicKey}) ->
#client_key_exchange{
exchange_keys = #client_diffie_hellman_public{
dh_public = PublicKey}
};
key_exchange(client, _Version, {ecdh, #'ECPrivateKey'{publicKey = ECPublicKey}}) ->
#client_key_exchange{
exchange_keys = #client_ec_diffie_hellman_public{
dh_public = ECPublicKey}
};
key_exchange(client, _Version, {psk, Identity}) ->
#client_key_exchange{
exchange_keys = #client_psk_identity{
identity = Identity}
};
key_exchange(client, _Version, {dhe_psk, Identity, PublicKey}) ->
#client_key_exchange{
exchange_keys = #client_dhe_psk_identity{
identity = Identity,
dh_public = PublicKey}
};
key_exchange(client, _Version, {ecdhe_psk, Identity, #'ECPrivateKey'{publicKey = ECPublicKey}}) ->
#client_key_exchange{
exchange_keys = #client_ecdhe_psk_identity{
identity = Identity,
dh_public = ECPublicKey}
};
key_exchange(client, _Version, {psk_premaster_secret, PskIdentity, Secret, {_, PublicKey, _}}) ->
EncPremasterSecret =
encrypted_premaster_secret(Secret, PublicKey),
#client_key_exchange{
exchange_keys = #client_rsa_psk_identity{
identity = PskIdentity,
exchange_keys = EncPremasterSecret}};
key_exchange(client, _Version, {srp, PublicKey}) ->
#client_key_exchange{
exchange_keys = #client_srp_public{
srp_a = PublicKey}
};
key_exchange(server, Version, {dh, {PublicKey, _},
#'DHParameter'{prime = P, base = G},
HashSign, ClientRandom, ServerRandom, PrivateKey}) ->
ServerDHParams = #server_dh_params{dh_p = int_to_bin(P),
dh_g = int_to_bin(G), dh_y = PublicKey},
enc_server_key_exchange(Version, ServerDHParams, HashSign,
ClientRandom, ServerRandom, PrivateKey);
key_exchange(server, Version, {ecdh, #'ECPrivateKey'{publicKey = ECPublicKey,
parameters = ECCurve}, HashSign,
ClientRandom, ServerRandom, PrivateKey}) ->
ServerECParams = #server_ecdh_params{curve = ECCurve, public = ECPublicKey},
enc_server_key_exchange(Version, ServerECParams, HashSign,
ClientRandom, ServerRandom, PrivateKey);
key_exchange(server, Version, {psk, PskIdentityHint,
HashSign, ClientRandom, ServerRandom, PrivateKey}) ->
ServerPSKParams = #server_psk_params{hint = PskIdentityHint},
enc_server_key_exchange(Version, ServerPSKParams, HashSign,
ClientRandom, ServerRandom, PrivateKey);
key_exchange(server, Version, {dhe_psk, PskIdentityHint, {PublicKey, _},
#'DHParameter'{prime = P, base = G},
HashSign, ClientRandom, ServerRandom, PrivateKey}) ->
ServerEDHPSKParams = #server_dhe_psk_params{
hint = PskIdentityHint,
dh_params = #server_dh_params{dh_p = int_to_bin(P),
dh_g = int_to_bin(G), dh_y = PublicKey}
},
enc_server_key_exchange(Version, ServerEDHPSKParams,
HashSign, ClientRandom, ServerRandom, PrivateKey);
key_exchange(server, Version, {ecdhe_psk, PskIdentityHint,
#'ECPrivateKey'{publicKey = ECPublicKey,
parameters = ECCurve},
HashSign, ClientRandom, ServerRandom, PrivateKey}) ->
ServerECDHEPSKParams = #server_ecdhe_psk_params{
hint = PskIdentityHint,
dh_params = #server_ecdh_params{curve = ECCurve, public = ECPublicKey}},
enc_server_key_exchange(Version, ServerECDHEPSKParams, HashSign,
ClientRandom, ServerRandom, PrivateKey);
key_exchange(server, Version, {srp, {PublicKey, _},
#srp_user{generator = Generator, prime = Prime,
salt = Salt},
HashSign, ClientRandom, ServerRandom, PrivateKey}) ->
ServerSRPParams = #server_srp_params{srp_n = Prime, srp_g = Generator,
srp_s = Salt, srp_b = PublicKey},
enc_server_key_exchange(Version, ServerSRPParams, HashSign,
ClientRandom, ServerRandom, PrivateKey).
%%--------------------------------------------------------------------
-spec finished(ssl_record:ssl_version(), client | server, integer(), binary(), ssl_handshake_history()) ->
#finished{}.
%%
%% Description: Creates a handshake finished message
%%-------------------------------------------------------------------
finished(Version, Role, PrfAlgo, MasterSecret, {Handshake, _}) -> % use the current handshake
#finished{verify_data =
calc_finished(Version, Role, PrfAlgo, MasterSecret, Handshake)}.
%%--------------------------------------------------------------------
-spec next_protocol(binary()) -> #next_protocol{}.
%%
%% Description: Creates a next protocol message
%%-------------------------------------------------------------------
next_protocol(SelectedProtocol) ->
#next_protocol{selected_protocol = SelectedProtocol}.
%%====================================================================
%% Handle handshake messages
%%====================================================================
%%--------------------------------------------------------------------
-spec certify(#certificate{}, db_handle(), certdb_ref(), #ssl_options{}, term(),
client | server, inet:hostname() | inet:ip_address()) -> {der_cert(), public_key_info()} | #alert{}.
%%
%% Description: Handles a certificate handshake message
%%--------------------------------------------------------------------
certify(#certificate{asn1_certificates = ASN1Certs}, CertDbHandle, CertDbRef,
Opts, CRLDbHandle, Role, Host) ->
ServerName = server_name(Opts#ssl_options.server_name_indication, Host, Role),
[PeerCert | ChainCerts ] = ASN1Certs,
try
{TrustedCert, CertPath} =
ssl_certificate:trusted_cert_and_path(ASN1Certs, CertDbHandle, CertDbRef,
Opts#ssl_options.partial_chain),
ValidationFunAndState = validation_fun_and_state(Opts#ssl_options.verify_fun, Role,
CertDbHandle, CertDbRef, ServerName,
Opts#ssl_options.customize_hostname_check,
Opts#ssl_options.crl_check, CRLDbHandle, CertPath),
Options = [{max_path_length, Opts#ssl_options.depth},
{verify_fun, ValidationFunAndState}],
case public_key:pkix_path_validation(TrustedCert, CertPath, Options) of
{ok, {PublicKeyInfo,_}} ->
{PeerCert, PublicKeyInfo};
{error, Reason} ->
handle_path_validation_error(Reason, PeerCert, ChainCerts, Opts, Options,
CertDbHandle, CertDbRef)
end
catch
error:{badmatch,{asn1, Asn1Reason}} ->
%% ASN-1 decode of certificate somehow failed
?ALERT_REC(?FATAL, ?CERTIFICATE_UNKNOWN, {failed_to_decode_certificate, Asn1Reason});
error:OtherReason ->
?ALERT_REC(?FATAL, ?INTERNAL_ERROR, {unexpected_error, OtherReason})
end.
%%--------------------------------------------------------------------
-spec certificate_verify(binary(), public_key_info(), ssl_record:ssl_version(), term(),
binary(), ssl_handshake_history()) -> valid | #alert{}.
%%
%% Description: Checks that the certificate_verify message is valid.
%%--------------------------------------------------------------------
certificate_verify(_, _, _, undefined, _, _) ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, invalid_certificate_verify_message);
certificate_verify(Signature, PublicKeyInfo, Version,
HashSign = {HashAlgo, _}, MasterSecret, {_, Handshake}) ->
Hash = calc_certificate_verify(Version, HashAlgo, MasterSecret, Handshake),
case verify_signature(Version, Hash, HashSign, Signature, PublicKeyInfo) of
true ->
valid;
_ ->
?ALERT_REC(?FATAL, ?BAD_CERTIFICATE)
end.
%%--------------------------------------------------------------------
-spec verify_signature(ssl_record:ssl_version(), binary(), {term(), term()}, binary(),
public_key_info()) -> true | false.
%%
%% Description: Checks that a public_key signature is valid.
%%--------------------------------------------------------------------
verify_signature(_Version, _Hash, {_HashAlgo, anon}, _Signature, _) ->
true;
verify_signature({3, Minor}, Hash, {HashAlgo, rsa}, Signature, {?rsaEncryption, PubKey, _PubKeyParams})
when Minor >= 3 ->
public_key:verify({digest, Hash}, HashAlgo, Signature, PubKey);
verify_signature(_Version, Hash, _HashAlgo, Signature, {?rsaEncryption, PubKey, _PubKeyParams}) ->
case public_key:decrypt_public(Signature, PubKey,
[{rsa_pad, rsa_pkcs1_padding}]) of
Hash -> true;
_ -> false
end;
verify_signature(_Version, Hash, {HashAlgo, dsa}, Signature, {?'id-dsa', PublicKey, PublicKeyParams}) ->
public_key:verify({digest, Hash}, HashAlgo, Signature, {PublicKey, PublicKeyParams});
verify_signature(_, Hash, {HashAlgo, _SignAlg}, Signature,
{?'id-ecPublicKey', PublicKey, PublicKeyParams}) ->
public_key:verify({digest, Hash}, HashAlgo, Signature, {PublicKey, PublicKeyParams}).
%%--------------------------------------------------------------------
-spec master_secret(ssl_record:ssl_version(), #session{} | binary(), ssl_record:connection_states(),
client | server) -> {binary(), ssl_record:connection_states()} | #alert{}.
%%
%% Description: Sets or calculates the master secret and calculate keys,
%% updating the pending connection states. The Mastersecret and the update
%% connection states are returned or an alert if the calculation fails.
%%-------------------------------------------------------------------
master_secret(Version, #session{master_secret = Mastersecret},
ConnectionStates, Role) ->
#{security_parameters := SecParams} =
ssl_record:pending_connection_state(ConnectionStates, read),
try master_secret(Version, Mastersecret, SecParams,
ConnectionStates, Role)
catch
exit:_ ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, key_calculation_failure)
end;
master_secret(Version, PremasterSecret, ConnectionStates, Role) ->
#{security_parameters := SecParams} =
ssl_record:pending_connection_state(ConnectionStates, read),
#security_parameters{prf_algorithm = PrfAlgo,
client_random = ClientRandom,
server_random = ServerRandom} = SecParams,
try master_secret(Version,
calc_master_secret(Version,PrfAlgo,PremasterSecret,
ClientRandom, ServerRandom),
SecParams, ConnectionStates, Role)
catch
exit:_ ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, master_secret_calculation_failure)
end.
%%--------------------------------------------------------------------
-spec server_key_exchange_hash(md5sha | md5 | sha | sha224 |sha256 | sha384 | sha512, binary()) -> binary().
%%
%% Description: Calculate server key exchange hash
%%--------------------------------------------------------------------
server_key_exchange_hash(md5sha, Value) ->
MD5 = crypto:hash(md5, Value),
SHA = crypto:hash(sha, Value),
<<MD5/binary, SHA/binary>>;
server_key_exchange_hash(Hash, Value) ->
crypto:hash(Hash, Value).
%%--------------------------------------------------------------------
-spec verify_connection(ssl_record:ssl_version(), #finished{}, client | server, integer(), binary(),
ssl_handshake_history()) -> verified | #alert{}.
%%
%% Description: Checks the ssl handshake finished message to verify
%% the connection.
%%-------------------------------------------------------------------
verify_connection(Version, #finished{verify_data = Data},
Role, PrfAlgo, MasterSecret, {_, Handshake}) ->
%% use the previous hashes
case calc_finished(Version, Role, PrfAlgo, MasterSecret, Handshake) of
Data ->
verified;
_ ->
?ALERT_REC(?FATAL, ?DECRYPT_ERROR)
end.
%%--------------------------------------------------------------------
-spec init_handshake_history() -> ssl_handshake_history().
%%
%% Description: Initialize the empty handshake history buffer.
%%--------------------------------------------------------------------
init_handshake_history() ->
{[], []}.
%%--------------------------------------------------------------------
-spec update_handshake_history(ssl_handshake:ssl_handshake_history(), Data ::term()) ->
ssl_handshake:ssl_handshake_history().
%%
%% Description: Update the handshake history buffer with Data.
%%--------------------------------------------------------------------
update_handshake_history({Handshake0, _Prev}, Data) ->
{[Data|Handshake0], Handshake0}.
verify_server_key(#server_key_params{params_bin = EncParams,
signature = Signature},
HashSign = {HashAlgo, _},
ConnectionStates, Version, PubKeyInfo) ->
#{security_parameters := SecParams} =
ssl_record:pending_connection_state(ConnectionStates, read),
#security_parameters{client_random = ClientRandom,
server_random = ServerRandom} = SecParams,
Hash = server_key_exchange_hash(HashAlgo,
<<ClientRandom/binary,
ServerRandom/binary,
EncParams/binary>>),
verify_signature(Version, Hash, HashSign, Signature, PubKeyInfo).
select_version(RecordCB, ClientVersion, Versions) ->
do_select_version(RecordCB, ClientVersion, Versions).
%% Called by TLS 1.2/1.3 Server when "supported_versions" is present
%% in ClientHello.
%% Input lists are ordered (highest first)
select_supported_version([], _ServerVersions) ->
undefined;
select_supported_version([ClientVersion|T], ServerVersions) ->
case lists:member(ClientVersion, ServerVersions) of
true ->
ClientVersion;
false ->
select_supported_version(T, ServerVersions)
end.
%%====================================================================
%% Encode handshake
%%====================================================================
encode_handshake(#next_protocol{selected_protocol = SelectedProtocol}, _Version) ->
PaddingLength = 32 - ((byte_size(SelectedProtocol) + 2) rem 32),
{?NEXT_PROTOCOL, <<?BYTE((byte_size(SelectedProtocol))), SelectedProtocol/binary,
?BYTE(PaddingLength), 0:(PaddingLength * 8)>>};
encode_handshake(#server_hello{server_version = {Major, Minor},
random = Random,
session_id = Session_ID,
cipher_suite = CipherSuite,
compression_method = Comp_method,
extensions = Extensions}, _Version) ->
SID_length = byte_size(Session_ID),
ExtensionsBin = encode_hello_extensions(Extensions),
{?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32/binary,
?BYTE(SID_length), Session_ID/binary,
CipherSuite/binary, ?BYTE(Comp_method), ExtensionsBin/binary>>};
encode_handshake(#certificate{asn1_certificates = ASN1CertList}, _Version) ->
ASN1Certs = certs_from_list(ASN1CertList),
ACLen = erlang:iolist_size(ASN1Certs),
{?CERTIFICATE, <<?UINT24(ACLen), ASN1Certs:ACLen/binary>>};
encode_handshake(#server_key_exchange{exchange_keys = Keys}, _Version) ->
{?SERVER_KEY_EXCHANGE, Keys};
encode_handshake(#server_key_params{params_bin = Keys, hashsign = HashSign,
signature = Signature}, Version) ->
EncSign = enc_sign(HashSign, Signature, Version),
{?SERVER_KEY_EXCHANGE, <<Keys/binary, EncSign/binary>>};
encode_handshake(#certificate_request{certificate_types = CertTypes,
hashsign_algorithms = #hash_sign_algos{hash_sign_algos = HashSignAlgos},
certificate_authorities = CertAuths},
{Major, Minor})
when Major == 3, Minor >= 3 ->
HashSigns= << <<(ssl_cipher:hash_algorithm(Hash)):8, (ssl_cipher:sign_algorithm(Sign)):8>> ||
{Hash, Sign} <- HashSignAlgos >>,
CertTypesLen = byte_size(CertTypes),
HashSignsLen = byte_size(HashSigns),
CertAuthsLen = byte_size(CertAuths),
{?CERTIFICATE_REQUEST,
<<?BYTE(CertTypesLen), CertTypes/binary,
?UINT16(HashSignsLen), HashSigns/binary,
?UINT16(CertAuthsLen), CertAuths/binary>>
};
encode_handshake(#certificate_request{certificate_types = CertTypes,
certificate_authorities = CertAuths},
_Version) ->
CertTypesLen = byte_size(CertTypes),
CertAuthsLen = byte_size(CertAuths),
{?CERTIFICATE_REQUEST,
<<?BYTE(CertTypesLen), CertTypes/binary,
?UINT16(CertAuthsLen), CertAuths/binary>>
};
encode_handshake(#server_hello_done{}, _Version) ->
{?SERVER_HELLO_DONE, <<>>};
encode_handshake(#client_key_exchange{exchange_keys = ExchangeKeys}, Version) ->
{?CLIENT_KEY_EXCHANGE, encode_client_key(ExchangeKeys, Version)};
encode_handshake(#certificate_verify{signature = BinSig, hashsign_algorithm = HashSign}, Version) ->
EncSig = enc_sign(HashSign, BinSig, Version),
{?CERTIFICATE_VERIFY, EncSig};
encode_handshake(#finished{verify_data = VerifyData}, _Version) ->
{?FINISHED, VerifyData}.
encode_hello_extensions(Extensions) ->
encode_extensions(hello_extensions_list(Extensions), <<>>).
encode_extensions(Exts) ->
encode_extensions(Exts, <<>>).
encode_extensions([], <<>>) ->
<<>>;
encode_extensions([], Acc) ->
Size = byte_size(Acc),
<<?UINT16(Size), Acc/binary>>;
encode_extensions([#alpn{extension_data = ExtensionData} | Rest], Acc) ->
Len = byte_size(ExtensionData),
ExtLen = Len + 2,
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_extensions(Rest, <<?UINT16(?NEXTPROTONEG_EXT), ?UINT16(Len),
ExtensionData/binary, Acc/binary>>);
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_extensions(Rest, <<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), Info/binary, Acc/binary>>);
encode_extensions([#renegotiation_info{renegotiated_connection = Info} | Rest], Acc) ->
InfoLen = byte_size(Info),
Len = InfoLen +1,
encode_extensions(Rest, <<?UINT16(?RENEGOTIATION_EXT), ?UINT16(Len), ?BYTE(InfoLen),
Info/binary, Acc/binary>>);
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_extensions(Rest, <<?UINT16(?ELLIPTIC_CURVES_EXT),
?UINT16(Len), ?UINT16(ListLen), EllipticCurveList/binary, Acc/binary>>);
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_extensions(Rest, <<?UINT16(?EC_POINT_FORMATS_EXT),
?UINT16(Len), ?BYTE(ListLen), ECPointFormatList/binary, Acc/binary>>);
encode_extensions([#srp{username = UserName} | Rest], Acc) ->
SRPLen = byte_size(UserName),
Len = SRPLen + 2,
encode_extensions(Rest, <<?UINT16(?SRP_EXT), ?UINT16(Len), ?BYTE(SRPLen),
UserName/binary, Acc/binary>>);
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_extensions(Rest, <<?UINT16(?SIGNATURE_ALGORITHMS_EXT),
?UINT16(Len), ?UINT16(ListLen), SignAlgoList/binary, Acc/binary>>);
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_extensions(Rest, <<?UINT16(?SIGNATURE_ALGORITHMS_CERT_EXT),
?UINT16(Len), ?UINT16(ListLen), SignSchemeList/binary, Acc/binary>>);
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_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_extensions(Rest, <<?UINT16(?SUPPORTED_VERSIONS_EXT),
?UINT16(Len), ?UINT16(VerLen), Versions/binary, Acc/binary>>);
encode_extensions([#server_hello_selected_version{selected_version = Version0} | Rest], Acc) ->
Version = encode_versions([Version0]),
Len = byte_size(Version), %% 2
encode_extensions(Rest, <<?UINT16(?SUPPORTED_VERSIONS_EXT),
?UINT16(Len), Version/binary, Acc/binary>>).
encode_client_protocol_negotiation(undefined, _) ->
undefined;
encode_client_protocol_negotiation(_, false) ->
#next_protocol_negotiation{extension_data = <<>>};
encode_client_protocol_negotiation(_, _) ->
undefined.
encode_protocols_advertised_on_server(undefined) ->
undefined;
encode_protocols_advertised_on_server(Protocols) ->
#next_protocol_negotiation{extension_data = lists:foldl(fun encode_protocol/2, <<>>, Protocols)}.
%%====================================================================
%% Decode handshake
%%====================================================================
decode_handshake(_, ?HELLO_REQUEST, <<>>) ->
#hello_request{};
decode_handshake(_, ?NEXT_PROTOCOL, <<?BYTE(SelectedProtocolLength),
SelectedProtocol:SelectedProtocolLength/binary,
?BYTE(PaddingLength), _Padding:PaddingLength/binary>>) ->
#next_protocol{selected_protocol = SelectedProtocol};
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{
server_version = {Major,Minor},
random = Random,
session_id = Session_ID,
cipher_suite = Cipher_suite,
compression_method = Comp_method,
extensions = empty_hello_extensions(Version, server)};
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, Version, server),
#server_hello{
server_version = {Major,Minor},
random = Random,
session_id = Session_ID,
cipher_suite = Cipher_suite,
compression_method = Comp_method,
extensions = HelloExtensions};
decode_handshake(_Version, ?CERTIFICATE, <<?UINT24(ACLen), ASN1Certs:ACLen/binary>>) ->
#certificate{asn1_certificates = certs_to_list(ASN1Certs)};
decode_handshake(_Version, ?SERVER_KEY_EXCHANGE, Keys) ->
#server_key_exchange{exchange_keys = Keys};
decode_handshake({Major, Minor}, ?CERTIFICATE_REQUEST,
<<?BYTE(CertTypesLen), CertTypes:CertTypesLen/binary,
?UINT16(HashSignsLen), HashSigns:HashSignsLen/binary,
?UINT16(CertAuthsLen), CertAuths:CertAuthsLen/binary>>)
when Major >= 3, Minor >= 3 ->
HashSignAlgos = [{ssl_cipher:hash_algorithm(Hash), ssl_cipher:sign_algorithm(Sign)} ||
<<?BYTE(Hash), ?BYTE(Sign)>> <= HashSigns],
#certificate_request{certificate_types = CertTypes,
hashsign_algorithms = #hash_sign_algos{hash_sign_algos = HashSignAlgos},
certificate_authorities = CertAuths};
decode_handshake(_Version, ?CERTIFICATE_REQUEST,
<<?BYTE(CertTypesLen), CertTypes:CertTypesLen/binary,
?UINT16(CertAuthsLen), CertAuths:CertAuthsLen/binary>>) ->
#certificate_request{certificate_types = CertTypes,
certificate_authorities = CertAuths};
decode_handshake(_Version, ?SERVER_HELLO_DONE, <<>>) ->
#server_hello_done{};
decode_handshake({Major, Minor}, ?CERTIFICATE_VERIFY,<<HashSign:2/binary, ?UINT16(SignLen),
Signature:SignLen/binary>>)
when Major == 3, Minor >= 3 ->
#certificate_verify{hashsign_algorithm = dec_hashsign(HashSign), signature = Signature};
decode_handshake(_Version, ?CERTIFICATE_VERIFY,<<?UINT16(SignLen), Signature:SignLen/binary>>)->
#certificate_verify{signature = Signature};
decode_handshake(_Version, ?CLIENT_KEY_EXCHANGE, PKEPMS) ->
#client_key_exchange{exchange_keys = PKEPMS};
decode_handshake(_Version, ?FINISHED, VerifyData) ->
#finished{verify_data = 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(binary(), ssl_record:ssl_version(), client | server) -> map().
%%
%% Description: Decodes TLS 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()) ->
#server_key_params{}.
%%
%% Description: Decode server_key data and return appropriate type
%%--------------------------------------------------------------------
decode_server_key(ServerKey, Type, Version) ->
dec_server_key(ServerKey, key_exchange_alg(Type), Version).
%%--------------------------------------------------------------------
-spec decode_client_key(binary(), ssl_cipher_format:key_algo(), ssl_record:ssl_version()) ->
#encrypted_premaster_secret{}
| #client_diffie_hellman_public{}
| #client_ec_diffie_hellman_public{}
| #client_psk_identity{}
| #client_dhe_psk_identity{}
| #client_ecdhe_psk_identity{}
| #client_rsa_psk_identity{}
| #client_srp_public{}.
%%
%% Description: Decode client_key data and return appropriate type
%%--------------------------------------------------------------------
decode_client_key(ClientKey, Type, Version) ->
dec_client_key(ClientKey, key_exchange_alg(Type), Version).
%%--------------------------------------------------------------------
-spec decode_suites('2_bytes'|'3_bytes', binary()) -> list().
%%
%% Description:
%%--------------------------------------------------------------------
decode_suites('2_bytes', Dec) ->
from_2bytes(Dec);
decode_suites('3_bytes', Dec) ->
from_3bytes(Dec).
%%====================================================================
%% Cipher suite handling
%%====================================================================
available_suites(UserSuites, Version) ->
VersionSuites = ssl_cipher:all_suites(Version) ++ ssl_cipher:anonymous_suites(Version),
lists:filtermap(fun(Suite) -> lists:member(Suite, VersionSuites) end, UserSuites).
available_suites(ServerCert, UserSuites, Version, undefined, Curve) ->
Suites = ssl_cipher:filter(ServerCert, available_suites(UserSuites, Version), Version),
filter_unavailable_ecc_suites(Curve, Suites);
available_suites(ServerCert, UserSuites, Version, HashSigns, Curve) ->
Suites = available_suites(ServerCert, UserSuites, Version, undefined, Curve),
filter_hashsigns(Suites, [ssl_cipher_format:suite_definition(Suite) || Suite <- Suites], HashSigns,
Version, []).
available_signature_algs(undefined, _) ->
undefined;
available_signature_algs(SupportedHashSigns, Version) when Version >= {3, 3} ->
#hash_sign_algos{hash_sign_algos = SupportedHashSigns};
available_signature_algs(_, _) ->
undefined.
available_signature_algs(undefined, SupportedHashSigns, _, Version) when
Version >= {3,3} ->
SupportedHashSigns;
available_signature_algs(#hash_sign_algos{hash_sign_algos = ClientHashSigns}, SupportedHashSigns,
_, Version) when Version >= {3,3} ->
sets:to_list(sets:intersection(sets:from_list(ClientHashSigns),
sets:from_list(SupportedHashSigns)));
available_signature_algs(_, _, _, _) ->
undefined.
cipher_suites(Suites, Renegotiation, true) ->
%% TLS_FALLBACK_SCSV should be placed last -RFC7507
cipher_suites(Suites, Renegotiation) ++ [?TLS_FALLBACK_SCSV];
cipher_suites(Suites, Renegotiation, false) ->
cipher_suites(Suites, Renegotiation).
cipher_suites(Suites, false) ->
[?TLS_EMPTY_RENEGOTIATION_INFO_SCSV | Suites];
cipher_suites(Suites, true) ->
Suites.
%%--------------------------------------------------------------------
-spec prf(ssl_record:ssl_version(), non_neg_integer(), binary(), binary(), [binary()], non_neg_integer()) ->
{ok, binary()} | {error, undefined}.
%%
%% Description: use the TLS PRF to generate key material
%%--------------------------------------------------------------------
prf({3,0}, _, _, _, _, _) ->
{error, undefined};
prf({3,_N}, PRFAlgo, Secret, Label, Seed, WantedLength) ->
{ok, tls_v1:prf(PRFAlgo, Secret, Label, Seed, WantedLength)}.
select_session(SuggestedSessionId, CipherSuites, HashSigns, Compressions, Port, #session{ecc = ECCCurve0} =
Session, Version,
#ssl_options{ciphers = UserSuites, honor_cipher_order = HonorCipherOrder} = SslOpts,
Cache, CacheCb, Cert) ->
{SessionId, Resumed} = ssl_session:server_id(Port, SuggestedSessionId,
SslOpts, Cert,
Cache, CacheCb),
case Resumed of
undefined ->
Suites = available_suites(Cert, UserSuites, Version, HashSigns, ECCCurve0),
CipherSuite0 = select_cipher_suite(CipherSuites, Suites, HonorCipherOrder),
{ECCCurve, CipherSuite} = cert_curve(Cert, ECCCurve0, CipherSuite0),
Compression = select_compression(Compressions),
{new, Session#session{session_id = SessionId,
ecc = ECCCurve,
cipher_suite = CipherSuite,
compression_method = Compression}};
_ ->
{resumed, Resumed}
end.
supported_ecc({Major, Minor}) when ((Major == 3) and (Minor >= 1)) orelse (Major > 3) ->
Curves = tls_v1:ecc_curves(Minor),
#elliptic_curves{elliptic_curve_list = Curves};
supported_ecc(_) ->
#elliptic_curves{elliptic_curve_list = []}.
premaster_secret(OtherPublicDhKey, MyPrivateKey, #'DHParameter'{} = Params) ->
try
public_key:compute_key(OtherPublicDhKey, MyPrivateKey, Params)
catch
error:computation_failed ->
throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
end;
premaster_secret(PublicDhKey, PrivateDhKey, #server_dh_params{dh_p = Prime, dh_g = Base}) ->
try
crypto:compute_key(dh, PublicDhKey, PrivateDhKey, [Prime, Base])
catch
error:computation_failed ->
throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
end;
premaster_secret(#client_srp_public{srp_a = ClientPublicKey}, ServerKey, #srp_user{prime = Prime,
verifier = Verifier}) ->
try crypto:compute_key(srp, ClientPublicKey, ServerKey, {host, [Verifier, Prime, '6a']}) of
PremasterSecret ->
PremasterSecret
catch
error:_ ->
throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
end;
premaster_secret(#server_srp_params{srp_n = Prime, srp_g = Generator, srp_s = Salt, srp_b = Public},
ClientKeys, {Username, Password}) ->
case ssl_srp_primes:check_srp_params(Generator, Prime) of
ok ->
DerivedKey = crypto:hash(sha, [Salt, crypto:hash(sha, [Username, <<$:>>, Password])]),
try crypto:compute_key(srp, Public, ClientKeys, {user, [DerivedKey, Prime, Generator, '6a']}) of
PremasterSecret ->
PremasterSecret
catch
error ->
throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
end;
_ ->
throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
end;
premaster_secret(#client_rsa_psk_identity{
identity = PSKIdentity,
exchange_keys = #encrypted_premaster_secret{premaster_secret = EncPMS}
}, #'RSAPrivateKey'{} = Key, PSKLookup) ->
PremasterSecret = premaster_secret(EncPMS, Key),
psk_secret(PSKIdentity, PSKLookup, PremasterSecret);
premaster_secret(#server_dhe_psk_params{
hint = IdentityHint,
dh_params = #server_dh_params{dh_y = PublicDhKey} = Params},
PrivateDhKey,
LookupFun) ->
PremasterSecret = premaster_secret(PublicDhKey, PrivateDhKey, Params),
psk_secret(IdentityHint, LookupFun, PremasterSecret);
premaster_secret(#server_ecdhe_psk_params{
hint = IdentityHint,
dh_params = #server_ecdh_params{
public = ECServerPubKey}},
PrivateEcDhKey,
LookupFun) ->
PremasterSecret = premaster_secret(#'ECPoint'{point = ECServerPubKey}, PrivateEcDhKey),
psk_secret(IdentityHint, LookupFun, PremasterSecret);
premaster_secret({rsa_psk, PSKIdentity}, PSKLookup, RSAPremasterSecret) ->
psk_secret(PSKIdentity, PSKLookup, RSAPremasterSecret);
premaster_secret(#client_ecdhe_psk_identity{
identity = PSKIdentity,
dh_public = PublicEcDhPoint}, PrivateEcDhKey, PSKLookup) ->
PremasterSecret = premaster_secret(#'ECPoint'{point = PublicEcDhPoint}, PrivateEcDhKey),
psk_secret(PSKIdentity, PSKLookup, PremasterSecret).
premaster_secret(#client_dhe_psk_identity{
identity = PSKIdentity,
dh_public = PublicDhKey}, PrivateKey, #'DHParameter'{} = Params, PSKLookup) ->
PremasterSecret = premaster_secret(PublicDhKey, PrivateKey, Params),
psk_secret(PSKIdentity, PSKLookup, PremasterSecret).
premaster_secret(#client_psk_identity{identity = PSKIdentity}, PSKLookup) ->
psk_secret(PSKIdentity, PSKLookup);
premaster_secret({psk, PSKIdentity}, PSKLookup) ->
psk_secret(PSKIdentity, PSKLookup);
premaster_secret(#'ECPoint'{} = ECPoint, #'ECPrivateKey'{} = ECDHKeys) ->
public_key:compute_key(ECPoint, ECDHKeys);
premaster_secret(EncSecret, #'RSAPrivateKey'{} = RSAPrivateKey) ->
try public_key:decrypt_private(EncSecret, RSAPrivateKey,
[{rsa_pad, rsa_pkcs1_padding}])
catch
_:_ ->
throw(?ALERT_REC(?FATAL, ?DECRYPT_ERROR))
end.
%%====================================================================
%% Extensions handling
%%====================================================================
client_hello_extensions(Version, CipherSuites,
#ssl_options{signature_algs = SupportedHashSigns,
signature_algs_cert = SignatureSchemes,
eccs = SupportedECCs,
versions = Versions} = SslOpts, ConnectionStates, Renegotiation) ->
{EcPointFormats, EllipticCurves} =
case advertises_ec_ciphers(lists:map(fun ssl_cipher_format:suite_definition/1, CipherSuites)) of
true ->
client_ecc_extensions(SupportedECCs);
false ->
{undefined, undefined}
end,
SRP = srp_user(SslOpts),
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#{client_hello_versions =>
#client_hello_versions{versions = Versions},
signature_algs_cert =>
#signature_scheme_list{signature_scheme_list = SignatureSchemes}};
_Else ->
HelloExtensions
end.
handle_client_hello_extensions(RecordCB, Random, ClientCipherSuites,
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(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),
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
#alert{} = Alert ->
Alert;
Protocol ->
{Session, ConnectionStates, Protocol,
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#{next_protocol_negotiation =>
encode_protocols_advertised_on_server(ProtocolsToAdvertise)}}
end.
handle_server_hello_extensions(RecordCB, Random, CipherSuite, Compression,
Exts, Version,
#ssl_options{secure_renegotiate = SecureRenegotation,
next_protocol_selector = NextProtoSelector},
ConnectionStates0, Renegotiation) ->
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;
Protocol ->
{ConnectionStates, npn, Protocol}
end;
{error, Reason} ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, Reason);
[] ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, no_protocols_in_server_hello);
[_|_] ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, too_many_protocols_in_server_hello)
end.
select_curve(Client, Server) ->
select_curve(Client, Server, false).
select_curve(#elliptic_curves{elliptic_curve_list = ClientCurves},
#elliptic_curves{elliptic_curve_list = ServerCurves},
ServerOrder) ->
case ServerOrder of
false ->
select_shared_curve(ClientCurves, ServerCurves);
true ->
select_shared_curve(ServerCurves, ClientCurves)
end;
select_curve(undefined, _, _) ->
%% Client did not send ECC extension use default curve if
%% ECC cipher is negotiated
{namedCurve, ?secp256r1}.
%%--------------------------------------------------------------------
-spec select_hashsign(#hash_sign_algos{} | undefined, undefined | binary(),
atom(), [atom()], ssl_record:ssl_version()) ->
{atom(), atom()} | undefined | #alert{}.
%%
%% Description: Handles signature_algorithms hello extension (server)
%%--------------------------------------------------------------------
select_hashsign(_, _, KeyExAlgo, _, _Version) when KeyExAlgo == dh_anon;
KeyExAlgo == ecdh_anon;
KeyExAlgo == srp_anon;
KeyExAlgo == psk;
KeyExAlgo == dhe_psk;
KeyExAlgo == ecdhe_psk ->
{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
end;
select_hashsign(_, Cert, _, _, Version) ->
#'OTPCertificate'{tbsCertificate = TBSCert} = public_key:pkix_decode_cert(Cert, otp),
#'OTPSubjectPublicKeyInfo'{algorithm = {_,Algo, _}} = TBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo,
select_hashsign_algs(undefined, Algo, Version).
%%--------------------------------------------------------------------
-spec select_hashsign(#certificate_request{}, binary(),
[atom()], ssl_record:ssl_version()) ->
{atom(), atom()} | #alert{}.
%%
%% 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,
{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
true ->
case lists:filter(fun({_, S} = Algos) when S == SubSign ->
is_acceptable_hash_sign(Algos, SupportedHashSigns);
(_) ->
false
end, HashSigns) 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(#certificate_request{}, Cert, _, Version) ->
select_hashsign(undefined, Cert, undefined, [], Version).
%%--------------------------------------------------------------------
-spec select_hashsign_algs({atom(), atom()}| undefined, oid(), ssl_record:ssl_version()) ->
{atom(), atom()}.
%% Description: For TLS 1.2 hash function and signature algorithm pairs can be
%% negotiated with the signature_algorithms extension,
%% for previous versions always use appropriate defaults.
%% RFC 5246, Sect. 7.4.1.4.1. Signature Algorithms
%% If the client does not send the signature_algorithms extension, the
%% server MUST do the following: (e.i defaults for TLS 1.2)
%%
%% - If the negotiated key exchange algorithm is one of (RSA, DHE_RSA,
%% DH_RSA, RSA_PSK, ECDH_RSA, ECDHE_RSA), behave as if client had
%% sent the value {sha1,rsa}.
%%
%% - If the negotiated key exchange algorithm is one of (DHE_DSS,
%% DH_DSS), behave as if the client had sent the value {sha1,dsa}.
%%
%% - If the negotiated key exchange algorithm is one of (ECDH_ECDSA,
%% ECDHE_ECDSA), behave as if the client had sent value {sha1,ecdsa}.
%%--------------------------------------------------------------------
select_hashsign_algs(HashSign, _, {Major, Minor}) when HashSign =/= undefined andalso
Major >= 3 andalso Minor >= 3 ->
HashSign;
select_hashsign_algs(undefined, ?rsaEncryption, {Major, Minor}) when Major >= 3 andalso Minor >= 3 ->
{sha, rsa};
select_hashsign_algs(undefined,?'id-ecPublicKey', _) ->
{sha, ecdsa};
select_hashsign_algs(undefined, ?rsaEncryption, _) ->
{md5sha, rsa};
select_hashsign_algs(undefined, ?'id-dsa', _) ->
{sha, dsa}.
srp_user(#ssl_options{srp_identity = {UserName, _}}) ->
#srp{username = UserName};
srp_user(_) ->
undefined.
extension_value(undefined) ->
undefined;
extension_value(#sni{hostname = HostName}) ->
HostName;
extension_value(#ec_point_formats{ec_point_format_list = List}) ->
List;
extension_value(#elliptic_curves{elliptic_curve_list = List}) ->
List;
extension_value(#hash_sign_algos{hash_sign_algos = Algos}) ->
Algos;
extension_value(#alpn{extension_data = Data}) ->
Data;
extension_value(#next_protocol_negotiation{extension_data = Data}) ->
Data;
extension_value(#srp{username = Name}) ->
Name;
extension_value(#renegotiation_info{renegotiated_connection = Data}) ->
Data.
%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------
%%------------- Create handshake messages ----------------------------
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)>>;
certificate_types(_, _) ->
<<?BYTE(?RSA_SIGN)>>.
certificate_authorities(CertDbHandle, CertDbRef) ->
Authorities = certificate_authorities_from_db(CertDbHandle, CertDbRef),
Enc = fun(#'OTPCertificate'{tbsCertificate=TBSCert}) ->
OTPSubj = TBSCert#'OTPTBSCertificate'.subject,
DNEncodedBin = public_key:pkix_encode('Name', OTPSubj, otp),
DNEncodedLen = byte_size(DNEncodedBin),
<<?UINT16(DNEncodedLen), DNEncodedBin/binary>>
end,
list_to_binary([Enc(Cert) || {_, Cert} <- Authorities]).
certificate_authorities_from_db(CertDbHandle, CertDbRef) when is_reference(CertDbRef) ->
ConnectionCerts = fun({{Ref, _, _}, Cert}, Acc) when Ref == CertDbRef ->
[Cert | Acc];
(_, Acc) ->
Acc
end,
ssl_pkix_db:foldl(ConnectionCerts, [], CertDbHandle);
certificate_authorities_from_db(_CertDbHandle, {extracted, CertDbData}) ->
%% Cache disabled, Ref contains data
lists:foldl(fun({decoded, {_Key,Cert}}, Acc) -> [Cert | Acc] end,
[], CertDbData).
%%-------------Handle handshake messages --------------------------------
validation_fun_and_state({Fun, UserState0}, Role, CertDbHandle, CertDbRef,
ServerNameIndication, CustomizeHostCheck, CRLCheck, CRLDbHandle, CertPath) ->
{fun(OtpCert, {extension, _} = Extension, {SslState, UserState}) ->
case ssl_certificate:validate(OtpCert,
Extension,
SslState) of
{valid, NewSslState} ->
{valid, {NewSslState, UserState}};
{fail, Reason} ->
apply_user_fun(Fun, OtpCert, Reason, UserState,
SslState, CertPath);
{unknown, _} ->
apply_user_fun(Fun, OtpCert,
Extension, UserState, SslState, CertPath)
end;
(OtpCert, VerifyResult, {SslState, UserState}) ->
apply_user_fun(Fun, OtpCert, VerifyResult, UserState,
SslState, CertPath)
end, {{Role, CertDbHandle, CertDbRef, {ServerNameIndication, CustomizeHostCheck}, CRLCheck, CRLDbHandle}, UserState0}};
validation_fun_and_state(undefined, Role, CertDbHandle, CertDbRef,
ServerNameIndication, CustomizeHostCheck, CRLCheck, CRLDbHandle, CertPath) ->
{fun(OtpCert, {extension, _} = Extension, SslState) ->
ssl_certificate:validate(OtpCert,
Extension,
SslState);
(OtpCert, VerifyResult, SslState) when (VerifyResult == valid) or
(VerifyResult == valid_peer) ->
case crl_check(OtpCert, CRLCheck, CertDbHandle, CertDbRef,
CRLDbHandle, VerifyResult, CertPath) of
valid ->
ssl_certificate:validate(OtpCert,
VerifyResult,
SslState);
Reason ->
{fail, Reason}
end;
(OtpCert, VerifyResult, SslState) ->
ssl_certificate:validate(OtpCert,
VerifyResult,
SslState)
end, {Role, CertDbHandle, CertDbRef, {ServerNameIndication, CustomizeHostCheck}, CRLCheck, CRLDbHandle}}.
apply_user_fun(Fun, OtpCert, VerifyResult, UserState0,
{_, CertDbHandle, CertDbRef, _, CRLCheck, CRLDbHandle} = SslState, CertPath) when
(VerifyResult == valid) or (VerifyResult == valid_peer) ->
case Fun(OtpCert, VerifyResult, UserState0) of
{Valid, UserState} when (Valid == valid) or (Valid == valid_peer) ->
case crl_check(OtpCert, CRLCheck, CertDbHandle, CertDbRef,
CRLDbHandle, VerifyResult, CertPath) of
valid ->
{Valid, {SslState, UserState}};
Result ->
apply_user_fun(Fun, OtpCert, Result, UserState, SslState, CertPath)
end;
{fail, _} = Fail ->
Fail
end;
apply_user_fun(Fun, OtpCert, ExtensionOrError, UserState0, SslState, _CertPath) ->
case Fun(OtpCert, ExtensionOrError, UserState0) of
{Valid, UserState} when (Valid == valid) or (Valid == valid_peer)->
{Valid, {SslState, UserState}};
{fail, _} = Fail ->
Fail;
{unknown, UserState} ->
{unknown, {SslState, UserState}}
end.
handle_path_validation_error({bad_cert, unknown_ca} = Reason, PeerCert, Chain,
Opts, Options, CertDbHandle, CertsDbRef) ->
handle_incomplete_chain(PeerCert, Chain, Opts, Options, CertDbHandle, CertsDbRef, Reason);
handle_path_validation_error({bad_cert, invalid_issuer} = Reason, PeerCert, Chain0,
Opts, Options, CertDbHandle, CertsDbRef) ->
case ssl_certificate:certificate_chain(PeerCert, CertDbHandle, CertsDbRef, Chain0) of
{ok, _, [PeerCert | Chain] = OrdedChain} when Chain =/= Chain0 -> %% Chain appaears to be unorded
{Trusted, Path} = ssl_certificate:trusted_cert_and_path(OrdedChain,
CertDbHandle, CertsDbRef,
Opts#ssl_options.partial_chain),
case public_key:pkix_path_validation(Trusted, Path, Options) of
{ok, {PublicKeyInfo,_}} ->
{PeerCert, PublicKeyInfo};
{error, PathError} ->
handle_path_validation_error(PathError, PeerCert, Path,
Opts, Options, CertDbHandle, CertsDbRef)
end;
_ ->
path_validation_alert(Reason)
end;
handle_path_validation_error(Reason, _, _, _, _,_, _) ->
path_validation_alert(Reason).
handle_incomplete_chain(PeerCert, Chain0, Opts, Options, CertDbHandle, CertsDbRef, PathError0) ->
case ssl_certificate:certificate_chain(PeerCert, CertDbHandle, CertsDbRef) of
{ok, _, [PeerCert | _] = Chain} when Chain =/= Chain0 -> %% Chain candidate found
{Trusted, Path} = ssl_certificate:trusted_cert_and_path(Chain,
CertDbHandle, CertsDbRef,
Opts#ssl_options.partial_chain),
case public_key:pkix_path_validation(Trusted, Path, Options) of
{ok, {PublicKeyInfo,_}} ->
{PeerCert, PublicKeyInfo};
{error, PathError} ->
path_validation_alert(PathError)
end;
_ ->
path_validation_alert(PathError0)
end.
path_validation_alert({bad_cert, cert_expired}) ->
?ALERT_REC(?FATAL, ?CERTIFICATE_EXPIRED);
path_validation_alert({bad_cert, invalid_issuer}) ->
?ALERT_REC(?FATAL, ?BAD_CERTIFICATE);
path_validation_alert({bad_cert, invalid_signature}) ->
?ALERT_REC(?FATAL, ?BAD_CERTIFICATE);
path_validation_alert({bad_cert, name_not_permitted}) ->
?ALERT_REC(?FATAL, ?BAD_CERTIFICATE);
path_validation_alert({bad_cert, unknown_critical_extension}) ->
?ALERT_REC(?FATAL, ?UNSUPPORTED_CERTIFICATE);
path_validation_alert({bad_cert, {revoked, _}}) ->
?ALERT_REC(?FATAL, ?CERTIFICATE_REVOKED);
path_validation_alert({bad_cert, {revocation_status_undetermined, Details}}) ->
Alert = ?ALERT_REC(?FATAL, ?BAD_CERTIFICATE),
Alert#alert{reason = Details};
path_validation_alert({bad_cert, selfsigned_peer}) ->
?ALERT_REC(?FATAL, ?BAD_CERTIFICATE);
path_validation_alert({bad_cert, unknown_ca}) ->
?ALERT_REC(?FATAL, ?UNKNOWN_CA);
path_validation_alert(Reason) ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, Reason).
digitally_signed(Version, Hashes, HashAlgo, PrivateKey) ->
try do_digitally_signed(Version, Hashes, HashAlgo, PrivateKey) of
Signature ->
Signature
catch
error:badkey->
throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, bad_key(PrivateKey)))
end.
do_digitally_signed({3, Minor}, Hash, HashAlgo, #{algorithm := Alg} = Engine)
when Minor >= 3 ->
crypto:sign(Alg, HashAlgo, {digest, Hash}, maps:remove(algorithm, Engine));
do_digitally_signed({3, Minor}, Hash, HashAlgo, Key) when Minor >= 3 ->
public_key:sign({digest, Hash}, HashAlgo, Key);
do_digitally_signed(_Version, Hash, _HashAlgo, #'RSAPrivateKey'{} = Key) ->
public_key:encrypt_private(Hash, Key,
[{rsa_pad, rsa_pkcs1_padding}]);
do_digitally_signed({3, _}, Hash, _,
#{algorithm := rsa} = Engine) ->
crypto:private_encrypt(rsa, Hash, maps:remove(algorithm, Engine),
rsa_pkcs1_padding);
do_digitally_signed({3, _}, Hash, HashAlgo, #{algorithm := Alg} = Engine) ->
crypto:sign(Alg, HashAlgo, {digest, Hash}, maps:remove(algorithm, Engine));
do_digitally_signed(_Version, Hash, HashAlgo, Key) ->
public_key:sign({digest, Hash}, HashAlgo, Key).
bad_key(#'DSAPrivateKey'{}) ->
unacceptable_dsa_key;
bad_key(#'RSAPrivateKey'{}) ->
unacceptable_rsa_key;
bad_key(#'ECPrivateKey'{}) ->
unacceptable_ecdsa_key.
crl_check(_, false, _,_,_, _, _) ->
valid;
crl_check(_, peer, _, _,_, valid, _) -> %% Do not check CAs with this option.
valid;
crl_check(OtpCert, Check, CertDbHandle, CertDbRef, {Callback, CRLDbHandle}, _, CertPath) ->
Options = [{issuer_fun, {fun(_DP, CRL, Issuer, DBInfo) ->
ssl_crl:trusted_cert_and_path(CRL, Issuer, {CertPath,
DBInfo})
end, {CertDbHandle, CertDbRef}}},
{update_crl, fun(DP, CRL) -> Callback:fresh_crl(DP, CRL) end},
{undetermined_details, true}
],
case dps_and_crls(OtpCert, Callback, CRLDbHandle, ext) of
no_dps ->
crl_check_same_issuer(OtpCert, Check,
dps_and_crls(OtpCert, Callback, CRLDbHandle, same_issuer),
Options);
DpsAndCRLs -> %% This DP list may be empty if relevant CRLs existed
%% but could not be retrived, will result in {bad_cert, revocation_status_undetermined}
case public_key:pkix_crls_validate(OtpCert, DpsAndCRLs, Options) of
{bad_cert, {revocation_status_undetermined, _}} ->
crl_check_same_issuer(OtpCert, Check, dps_and_crls(OtpCert, Callback,
CRLDbHandle, same_issuer), Options);
Other ->
Other
end
end.
crl_check_same_issuer(OtpCert, best_effort, Dps, Options) ->
case public_key:pkix_crls_validate(OtpCert, Dps, Options) of
{bad_cert, {revocation_status_undetermined, _}} ->
valid;
Other ->
Other
end;
crl_check_same_issuer(OtpCert, _, Dps, Options) ->
public_key:pkix_crls_validate(OtpCert, Dps, Options).
dps_and_crls(OtpCert, Callback, CRLDbHandle, ext) ->
case public_key:pkix_dist_points(OtpCert) of
[] ->
no_dps;
DistPoints ->
Issuer = OtpCert#'OTPCertificate'.tbsCertificate#'OTPTBSCertificate'.issuer,
CRLs = distpoints_lookup(DistPoints, Issuer, Callback, CRLDbHandle),
dps_and_crls(DistPoints, CRLs, [])
end;
dps_and_crls(OtpCert, Callback, CRLDbHandle, same_issuer) ->
DP = #'DistributionPoint'{distributionPoint = {fullName, GenNames}} =
public_key:pkix_dist_point(OtpCert),
CRLs = lists:flatmap(fun({directoryName, Issuer}) ->
Callback:select(Issuer, CRLDbHandle);
(_) ->
[]
end, GenNames),
[{DP, {CRL, public_key:der_decode('CertificateList', CRL)}} || CRL <- CRLs].
dps_and_crls([], _, Acc) ->
Acc;
dps_and_crls([DP | Rest], CRLs, Acc) ->
DpCRL = [{DP, {CRL, public_key:der_decode('CertificateList', CRL)}} || CRL <- CRLs],
dps_and_crls(Rest, CRLs, DpCRL ++ Acc).
distpoints_lookup([],_, _, _) ->
[];
distpoints_lookup([DistPoint | Rest], Issuer, Callback, CRLDbHandle) ->
Result =
try Callback:lookup(DistPoint, Issuer, CRLDbHandle)
catch
error:undef ->
%% The callback module still uses the 2-argument
%% version of the lookup function.
Callback:lookup(DistPoint, CRLDbHandle)
end,
case Result of
not_available ->
distpoints_lookup(Rest, Issuer, Callback, CRLDbHandle);
CRLs ->
CRLs
end.
encrypted_premaster_secret(Secret, RSAPublicKey) ->
try
PreMasterSecret = public_key:encrypt_public(Secret, RSAPublicKey,
[{rsa_pad,
rsa_pkcs1_padding}]),
#encrypted_premaster_secret{premaster_secret = PreMasterSecret}
catch
_:_->
throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, premaster_encryption_failed))
end.
calc_certificate_verify({3, 0}, HashAlgo, MasterSecret, Handshake) ->
ssl_v3:certificate_verify(HashAlgo, MasterSecret, lists:reverse(Handshake));
calc_certificate_verify({3, N}, HashAlgo, _MasterSecret, Handshake) ->
tls_v1:certificate_verify(HashAlgo, N, lists:reverse(Handshake)).
calc_finished({3, 0}, Role, _PrfAlgo, MasterSecret, Handshake) ->
ssl_v3:finished(Role, MasterSecret, lists:reverse(Handshake));
calc_finished({3, N}, Role, PrfAlgo, MasterSecret, Handshake) ->
tls_v1:finished(Role, N, PrfAlgo, MasterSecret, lists:reverse(Handshake)).
master_secret(Version, MasterSecret,
#security_parameters{
bulk_cipher_algorithm = BCA,
client_random = ClientRandom,
server_random = ServerRandom,
hash_size = HashSize,
prf_algorithm = PrfAlgo,
key_material_length = KML,
expanded_key_material_length = EKML,
iv_size = IVS},
ConnectionStates, Role) ->
{ClientWriteMacSecret, ServerWriteMacSecret, ClientWriteKey,
ServerWriteKey, ClientIV, ServerIV} =
setup_keys(Version, PrfAlgo, MasterSecret, ServerRandom,
ClientRandom, HashSize, KML, EKML, IVS),
ConnStates1 = ssl_record:set_master_secret(MasterSecret, ConnectionStates),
ConnStates2 =
ssl_record:set_mac_secret(ClientWriteMacSecret, ServerWriteMacSecret,
Role, ConnStates1),
ClientCipherState = ssl_cipher:cipher_init(BCA, ClientIV, ClientWriteKey),
ServerCipherState = ssl_cipher:cipher_init(BCA, ServerIV, ServerWriteKey),
{MasterSecret,
ssl_record:set_pending_cipher_state(ConnStates2, ClientCipherState,
ServerCipherState, Role)}.
setup_keys({3,0}, _PrfAlgo, MasterSecret,
ServerRandom, ClientRandom, HashSize, KML, EKML, IVS) ->
ssl_v3:setup_keys(MasterSecret, ServerRandom,
ClientRandom, HashSize, KML, EKML, IVS);
setup_keys({3,N}, PrfAlgo, MasterSecret,
ServerRandom, ClientRandom, HashSize, KML, _EKML, IVS) ->
tls_v1:setup_keys(N, PrfAlgo, MasterSecret, ServerRandom, ClientRandom, HashSize,
KML, IVS).
calc_master_secret({3,0}, _PrfAlgo, PremasterSecret, ClientRandom, ServerRandom) ->
ssl_v3:master_secret(PremasterSecret, ClientRandom, ServerRandom);
calc_master_secret({3,_}, PrfAlgo, PremasterSecret, ClientRandom, ServerRandom) ->
tls_v1:master_secret(PrfAlgo, PremasterSecret, ClientRandom, ServerRandom).
%% Update pending connection states with parameters exchanged via
%% hello messages
%% NOTE : Role is the role of the receiver of the hello message
%% currently being processed.
hello_pending_connection_states(_RecordCB, Role, Version, CipherSuite, Random, Compression,
ConnectionStates) ->
ReadState =
ssl_record:pending_connection_state(ConnectionStates, read),
WriteState =
ssl_record:pending_connection_state(ConnectionStates, write),
NewReadSecParams =
hello_security_parameters(Role, Version, ReadState, CipherSuite,
Random, Compression),
NewWriteSecParams =
hello_security_parameters(Role, Version, WriteState, CipherSuite,
Random, Compression),
ssl_record:set_security_params(NewReadSecParams,
NewWriteSecParams,
ConnectionStates).
hello_security_parameters(client, Version, #{security_parameters := SecParams}, CipherSuite, Random,
Compression) ->
NewSecParams = ssl_cipher:security_parameters(Version, CipherSuite, SecParams),
NewSecParams#security_parameters{
server_random = Random,
compression_algorithm = Compression
};
hello_security_parameters(server, Version, #{security_parameters := SecParams}, CipherSuite, Random,
Compression) ->
NewSecParams = ssl_cipher:security_parameters(Version, CipherSuite, SecParams),
NewSecParams#security_parameters{
client_random = Random,
compression_algorithm = Compression
}.
select_compression(_CompressionMetodes) ->
?NULL.
do_select_version(_, ClientVersion, []) ->
ClientVersion;
do_select_version(RecordCB, ClientVersion, [Version | Versions]) ->
case RecordCB:is_higher(Version, ClientVersion) of
true ->
%% Version too high for client - keep looking
do_select_version(RecordCB, ClientVersion, Versions);
false ->
%% Version ok for client - look for a higher
do_select_version(RecordCB, ClientVersion, Versions, Version)
end.
%%
do_select_version(_, _, [], GoodVersion) ->
GoodVersion;
do_select_version(
RecordCB, ClientVersion, [Version | Versions], GoodVersion) ->
BetterVersion =
case RecordCB:is_higher(Version, ClientVersion) of
true ->
%% Version too high for client
GoodVersion;
false ->
%% Version ok for client
case RecordCB:is_higher(Version, GoodVersion) of
true ->
%% Use higher version
Version;
false ->
GoodVersion
end
end,
do_select_version(RecordCB, ClientVersion, Versions, BetterVersion).
%%-------------Encode handshakes --------------------------------
encode_server_key(#server_dh_params{dh_p = P, dh_g = G, dh_y = Y}) ->
PLen = byte_size(P),
GLen = byte_size(G),
YLen = byte_size(Y),
<<?UINT16(PLen), P/binary, ?UINT16(GLen), G/binary, ?UINT16(YLen), Y/binary>>;
encode_server_key(#server_ecdh_params{curve = {namedCurve, ECCurve}, public = ECPubKey}) ->
%%TODO: support arbitrary keys
KLen = size(ECPubKey),
<<?BYTE(?NAMED_CURVE), ?UINT16((tls_v1:oid_to_enum(ECCurve))),
?BYTE(KLen), ECPubKey/binary>>;
encode_server_key(#server_psk_params{hint = PskIdentityHint}) ->
Len = byte_size(PskIdentityHint),
<<?UINT16(Len), PskIdentityHint/binary>>;
encode_server_key(Params = #server_dhe_psk_params{hint = undefined}) ->
encode_server_key(Params#server_dhe_psk_params{hint = <<>>});
encode_server_key(#server_dhe_psk_params{
hint = PskIdentityHint,
dh_params = #server_dh_params{dh_p = P, dh_g = G, dh_y = Y}}) ->
Len = byte_size(PskIdentityHint),
PLen = byte_size(P),
GLen = byte_size(G),
YLen = byte_size(Y),
<<?UINT16(Len), PskIdentityHint/binary,
?UINT16(PLen), P/binary, ?UINT16(GLen), G/binary, ?UINT16(YLen), Y/binary>>;
encode_server_key(Params = #server_ecdhe_psk_params{hint = undefined}) ->
encode_server_key(Params#server_ecdhe_psk_params{hint = <<>>});
encode_server_key(#server_ecdhe_psk_params{
hint = PskIdentityHint,
dh_params = #server_ecdh_params{
curve = {namedCurve, ECCurve}, public = ECPubKey}}) ->
%%TODO: support arbitrary keys
Len = byte_size(PskIdentityHint),
KLen = size(ECPubKey),
<<?UINT16(Len), PskIdentityHint/binary,
?BYTE(?NAMED_CURVE), ?UINT16((tls_v1:oid_to_enum(ECCurve))),
?BYTE(KLen), ECPubKey/binary>>;
encode_server_key(#server_srp_params{srp_n = N, srp_g = G, srp_s = S, srp_b = B}) ->
NLen = byte_size(N),
GLen = byte_size(G),
SLen = byte_size(S),
BLen = byte_size(B),
<<?UINT16(NLen), N/binary, ?UINT16(GLen), G/binary,
?BYTE(SLen), S/binary, ?UINT16(BLen), B/binary>>.
encode_client_key(#encrypted_premaster_secret{premaster_secret = PKEPMS},{3, 0}) ->
PKEPMS;
encode_client_key(#encrypted_premaster_secret{premaster_secret = PKEPMS}, _) ->
PKEPMSLen = byte_size(PKEPMS),
<<?UINT16(PKEPMSLen), PKEPMS/binary>>;
encode_client_key(#client_diffie_hellman_public{dh_public = DHPublic}, _) ->
Len = byte_size(DHPublic),
<<?UINT16(Len), DHPublic/binary>>;
encode_client_key(#client_ec_diffie_hellman_public{dh_public = DHPublic}, _) ->
Len = byte_size(DHPublic),
<<?BYTE(Len), DHPublic/binary>>;
encode_client_key(#client_psk_identity{identity = undefined}, _) ->
Id = <<"psk_identity">>,
Len = byte_size(Id),
<<?UINT16(Len), Id/binary>>;
encode_client_key(#client_psk_identity{identity = Id}, _) ->
Len = byte_size(Id),
<<?UINT16(Len), Id/binary>>;
encode_client_key(Identity = #client_dhe_psk_identity{identity = undefined}, Version) ->
encode_client_key(Identity#client_dhe_psk_identity{identity = <<"psk_identity">>}, Version);
encode_client_key(#client_dhe_psk_identity{identity = Id, dh_public = DHPublic}, _) ->
Len = byte_size(Id),
DHLen = byte_size(DHPublic),
<<?UINT16(Len), Id/binary, ?UINT16(DHLen), DHPublic/binary>>;
encode_client_key(Identity = #client_ecdhe_psk_identity{identity = undefined}, Version) ->
encode_client_key(Identity#client_ecdhe_psk_identity{identity = <<"psk_identity">>}, Version);
encode_client_key(#client_ecdhe_psk_identity{identity = Id, dh_public = DHPublic}, _) ->
Len = byte_size(Id),
DHLen = byte_size(DHPublic),
<<?UINT16(Len), Id/binary, ?BYTE(DHLen), DHPublic/binary>>;
encode_client_key(Identity = #client_rsa_psk_identity{identity = undefined}, Version) ->
encode_client_key(Identity#client_rsa_psk_identity{identity = <<"psk_identity">>}, Version);
encode_client_key(#client_rsa_psk_identity{identity = Id, exchange_keys = ExchangeKeys}, Version) ->
EncPMS = encode_client_key(ExchangeKeys, Version),
Len = byte_size(Id),
<<?UINT16(Len), Id/binary, EncPMS/binary>>;
encode_client_key(#client_srp_public{srp_a = A}, _) ->
Len = byte_size(A),
<<?UINT16(Len), A/binary>>.
enc_sign({_, anon}, _Sign, _Version) ->
<<>>;
enc_sign({HashAlg, SignAlg}, Signature, _Version = {Major, Minor})
when Major == 3, Minor >= 3->
SignLen = byte_size(Signature),
HashSign = enc_hashsign(HashAlg, SignAlg),
<<HashSign/binary, ?UINT16(SignLen), Signature/binary>>;
enc_sign(_HashSign, Sign, _Version) ->
SignLen = byte_size(Sign),
<<?UINT16(SignLen), Sign/binary>>.
enc_hashsign(HashAlgo, SignAlgo) ->
Hash = ssl_cipher:hash_algorithm(HashAlgo),
Sign = ssl_cipher:sign_algorithm(SignAlgo),
<<?BYTE(Hash), ?BYTE(Sign)>>.
encode_protocol(Protocol, Acc) ->
Len = byte_size(Protocol),
<<Acc/binary, ?BYTE(Len), Protocol/binary>>.
enc_server_key_exchange(Version, Params, {HashAlgo, SignAlgo},
ClientRandom, ServerRandom, PrivateKey) ->
EncParams = encode_server_key(Params),
case HashAlgo of
null ->
#server_key_params{params = Params,
params_bin = EncParams,
hashsign = {null, anon},
signature = <<>>};
_ ->
Hash =
server_key_exchange_hash(HashAlgo, <<ClientRandom/binary,
ServerRandom/binary,
EncParams/binary>>),
Signature = digitally_signed(Version, Hash, HashAlgo, PrivateKey),
#server_key_params{params = Params,
params_bin = EncParams,
hashsign = {HashAlgo, SignAlgo},
signature = Signature}
end.
%% While the RFC opens the door to allow ALPN during renegotiation, in practice
%% this does not work and it is recommended to ignore any ALPN extension during
%% renegotiation, as done here.
encode_alpn(_, true) ->
undefined;
encode_alpn(undefined, _) ->
undefined;
encode_alpn(Protocols, _) ->
#alpn{extension_data = lists:foldl(fun encode_protocol/2, <<>>, Protocols)}.
encode_versions(Versions) ->
encode_versions(lists:reverse(Versions), <<>>).
%%
encode_versions([], Acc) ->
Acc;
encode_versions([{M,N}|T], Acc) ->
encode_versions(T, <<?BYTE(M),?BYTE(N),Acc/binary>>).
hello_extensions_list(HelloExtensions) ->
[Ext || {_, Ext} <- maps:to_list(HelloExtensions), Ext =/= undefined].
%%-------------Decode handshakes---------------------------------
dec_server_key(<<?UINT16(PLen), P:PLen/binary,
?UINT16(GLen), G:GLen/binary,
?UINT16(YLen), Y:YLen/binary, _/binary>> = KeyStruct,
?KEY_EXCHANGE_DIFFIE_HELLMAN, Version) ->
Params = #server_dh_params{dh_p = P, dh_g = G, dh_y = Y},
{BinMsg, HashSign, Signature} = dec_server_key_params(PLen + GLen + YLen + 6, KeyStruct, Version),
#server_key_params{params = Params,
params_bin = BinMsg,
hashsign = HashSign,
signature = Signature};
%% ECParameters with named_curve
%% TODO: explicit curve
dec_server_key(<<?BYTE(?NAMED_CURVE), ?UINT16(CurveID),
?BYTE(PointLen), ECPoint:PointLen/binary,
_/binary>> = KeyStruct,
?KEY_EXCHANGE_EC_DIFFIE_HELLMAN, Version) ->
Params = #server_ecdh_params{curve = {namedCurve, tls_v1:enum_to_oid(CurveID)},
public = ECPoint},
{BinMsg, HashSign, Signature} = dec_server_key_params(PointLen + 4, KeyStruct, Version),
#server_key_params{params = Params,
params_bin = BinMsg,
hashsign = HashSign,
signature = Signature};
dec_server_key(<<?UINT16(Len), PskIdentityHint:Len/binary, _/binary>> = KeyStruct,
KeyExchange, Version)
when KeyExchange == ?KEY_EXCHANGE_PSK; KeyExchange == ?KEY_EXCHANGE_RSA_PSK ->
Params = #server_psk_params{
hint = PskIdentityHint},
{BinMsg, HashSign, Signature} = dec_server_key_params(Len + 2, KeyStruct, Version),
#server_key_params{params = Params,
params_bin = BinMsg,
hashsign = HashSign,
signature = Signature};
dec_server_key(<<?UINT16(Len), IdentityHint:Len/binary,
?UINT16(PLen), P:PLen/binary,
?UINT16(GLen), G:GLen/binary,
?UINT16(YLen), Y:YLen/binary, _/binary>> = KeyStruct,
?KEY_EXCHANGE_DHE_PSK, Version) ->
DHParams = #server_dh_params{dh_p = P, dh_g = G, dh_y = Y},
Params = #server_dhe_psk_params{
hint = IdentityHint,
dh_params = DHParams},
{BinMsg, HashSign, Signature} = dec_server_key_params(Len + PLen + GLen + YLen + 8, KeyStruct, Version),
#server_key_params{params = Params,
params_bin = BinMsg,
hashsign = HashSign,
signature = Signature};
dec_server_key(<<?UINT16(Len), IdentityHint:Len/binary,
?BYTE(?NAMED_CURVE), ?UINT16(CurveID),
?BYTE(PointLen), ECPoint:PointLen/binary,
_/binary>> = KeyStruct,
?KEY_EXCHANGE_EC_DIFFIE_HELLMAN_PSK, Version) ->
DHParams = #server_ecdh_params{
curve = {namedCurve, tls_v1:enum_to_oid(CurveID)},
public = ECPoint},
Params = #server_ecdhe_psk_params{
hint = IdentityHint,
dh_params = DHParams},
{BinMsg, HashSign, Signature} = dec_server_key_params(Len + 2 + PointLen + 4, KeyStruct, Version),
#server_key_params{params = Params,
params_bin = BinMsg,
hashsign = HashSign,
signature = Signature};
dec_server_key(<<?UINT16(NLen), N:NLen/binary,
?UINT16(GLen), G:GLen/binary,
?BYTE(SLen), S:SLen/binary,
?UINT16(BLen), B:BLen/binary, _/binary>> = KeyStruct,
?KEY_EXCHANGE_SRP, Version) ->
Params = #server_srp_params{srp_n = N, srp_g = G, srp_s = S, srp_b = B},
{BinMsg, HashSign, Signature} = dec_server_key_params(NLen + GLen + SLen + BLen + 7, KeyStruct, Version),
#server_key_params{params = Params,
params_bin = BinMsg,
hashsign = HashSign,
signature = Signature};
dec_server_key(_, KeyExchange, _) ->
throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, {unknown_or_malformed_key_exchange, KeyExchange})).
dec_client_key(PKEPMS, ?KEY_EXCHANGE_RSA, {3, 0}) ->
#encrypted_premaster_secret{premaster_secret = PKEPMS};
dec_client_key(<<?UINT16(_), PKEPMS/binary>>, ?KEY_EXCHANGE_RSA, _) ->
#encrypted_premaster_secret{premaster_secret = PKEPMS};
dec_client_key(<<>>, ?KEY_EXCHANGE_DIFFIE_HELLMAN, _) ->
throw(?ALERT_REC(?FATAL, ?UNSUPPORTED_CERTIFICATE, empty_dh_public));
dec_client_key(<<?UINT16(DH_YLen), DH_Y:DH_YLen/binary>>,
?KEY_EXCHANGE_DIFFIE_HELLMAN, _) ->
#client_diffie_hellman_public{dh_public = DH_Y};
dec_client_key(<<>>, ?KEY_EXCHANGE_EC_DIFFIE_HELLMAN, _) ->
throw(?ALERT_REC(?FATAL, ?UNSUPPORTED_CERTIFICATE, empty_dh_public));
dec_client_key(<<?BYTE(DH_YLen), DH_Y:DH_YLen/binary>>,
?KEY_EXCHANGE_EC_DIFFIE_HELLMAN, _) ->
#client_ec_diffie_hellman_public{dh_public = DH_Y};
dec_client_key(<<?UINT16(Len), Id:Len/binary>>,
?KEY_EXCHANGE_PSK, _) ->
#client_psk_identity{identity = Id};
dec_client_key(<<?UINT16(Len), Id:Len/binary,
?UINT16(DH_YLen), DH_Y:DH_YLen/binary>>,
?KEY_EXCHANGE_DHE_PSK, _) ->
#client_dhe_psk_identity{identity = Id, dh_public = DH_Y};
dec_client_key(<<?UINT16(Len), Id:Len/binary,
?BYTE(DH_YLen), DH_Y:DH_YLen/binary>>,
?KEY_EXCHANGE_EC_DIFFIE_HELLMAN_PSK, _) ->
#client_ecdhe_psk_identity{identity = Id, dh_public = DH_Y};
dec_client_key(<<?UINT16(Len), Id:Len/binary, PKEPMS/binary>>,
?KEY_EXCHANGE_RSA_PSK, {3, 0}) ->
#client_rsa_psk_identity{identity = Id,
exchange_keys = #encrypted_premaster_secret{premaster_secret = PKEPMS}};
dec_client_key(<<?UINT16(Len), Id:Len/binary, ?UINT16(_), PKEPMS/binary>>,
?KEY_EXCHANGE_RSA_PSK, _) ->
#client_rsa_psk_identity{identity = Id,
exchange_keys = #encrypted_premaster_secret{premaster_secret = PKEPMS}};
dec_client_key(<<?UINT16(ALen), A:ALen/binary>>,
?KEY_EXCHANGE_SRP, _) ->
#client_srp_public{srp_a = A}.
dec_server_key_params(Len, Keys, Version) ->
<<Params:Len/bytes, Signature/binary>> = Keys,
dec_server_key_signature(Params, Signature, Version).
dec_server_key_signature(Params, <<?BYTE(HashAlgo), ?BYTE(SignAlgo),
?UINT16(0)>>, {Major, Minor})
when Major == 3, Minor >= 3 ->
HashSign = {ssl_cipher:hash_algorithm(HashAlgo), ssl_cipher:sign_algorithm(SignAlgo)},
{Params, HashSign, <<>>};
dec_server_key_signature(Params, <<?BYTE(HashAlgo), ?BYTE(SignAlgo),
?UINT16(Len), Signature:Len/binary>>, {Major, Minor})
when Major == 3, Minor >= 3 ->
HashSign = {ssl_cipher:hash_algorithm(HashAlgo), ssl_cipher:sign_algorithm(SignAlgo)},
{Params, HashSign, Signature};
dec_server_key_signature(Params, <<>>, _) ->
{Params, {null, anon}, <<>>};
dec_server_key_signature(Params, <<?UINT16(0)>>, _) ->
{Params, {null, anon}, <<>>};
dec_server_key_signature(Params, <<?UINT16(Len), Signature:Len/binary>>, _) ->
{Params, undefined, Signature};
dec_server_key_signature(_, _, _) ->
throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, failed_to_decrypt_server_key_sign)).
decode_extensions(<<>>, Acc) ->
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},
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},
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
_ ->
VerifyLen = Len - 1,
<<?BYTE(VerifyLen), VerifyInfo/binary>> = Info,
VerifyInfo
end,
decode_extensions(Rest, Acc#{renegotiation_info =>
#renegotiation_info{renegotiated_connection =
RenegotiateInfo}});
decode_extensions(<<?UINT16(?SRP_EXT), ?UINT16(Len), ?BYTE(SRPLen), SRP:SRPLen/binary, Rest/binary>>, Acc)
when Len == SRPLen + 2 ->
decode_extensions(Rest, Acc#{srp => #srp{username = SRP}});
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],
decode_extensions(Rest, Acc#{signature_algs =>
#hash_sign_algos{hash_sign_algos = HashSignAlgos}});
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],
decode_extensions(Rest, Acc#{signature_algs_cert =>
#signature_scheme_list{
signature_scheme_list = SignSchemes}});
decode_extensions(<<?UINT16(?ELLIPTIC_CURVES_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) ->
<<?UINT16(_), EllipticCurveList/binary>> = ExtData,
%% Ignore unknown curves
Pick = fun(Enum) ->
case tls_v1:enum_to_oid(Enum) of
undefined ->
false;
Oid ->
{true, Oid}
end
end,
EllipticCurves = lists:filtermap(Pick, [ECC || <<ECC:16>> <= EllipticCurveList]),
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),
decode_extensions(Rest, Acc#{ec_point_formats =>
#ec_point_formats{ec_point_format_list =
ECPointFormats}});
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
decode_extensions(<<?UINT16(?SNI_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) ->
<<?UINT16(_), NameList/binary>> = ExtData,
decode_extensions(Rest, Acc#{sni => dec_sni(NameList)});
decode_extensions(<<?UINT16(?SUPPORTED_VERSIONS_EXT), ?UINT16(Len),
ExtData:Len/binary, Rest/binary>>, Acc) when Len > 2 ->
<<?UINT16(_),Versions/binary>> = ExtData,
decode_extensions(Rest, Acc#{client_hello_versions =>
#client_hello_versions{versions = decode_versions(Versions)}});
decode_extensions(<<?UINT16(?SUPPORTED_VERSIONS_EXT), ?UINT16(Len),
?UINT16(Version), Rest/binary>>, Acc) when Len =:= 2, Version =:= 16#0304 ->
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.
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.
decode_extensions(_, Acc) ->
Acc.
dec_hashsign(<<?BYTE(HashAlgo), ?BYTE(SignAlgo)>>) ->
{ssl_cipher:hash_algorithm(HashAlgo), ssl_cipher:sign_algorithm(SignAlgo)}.
%% Ignore unknown names (only host_name is supported)
dec_sni(<<?BYTE(?SNI_NAMETYPE_HOST_NAME), ?UINT16(Len),
HostName:Len/binary, _/binary>>) ->
#sni{hostname = binary_to_list(HostName)};
dec_sni(<<?BYTE(_), ?UINT16(Len), _:Len, Rest/binary>>) -> dec_sni(Rest);
dec_sni(_) -> undefined.
decode_alpn(undefined) ->
undefined;
decode_alpn(#alpn{extension_data=Data}) ->
decode_protocols(Data, []).
decode_versions(Versions) ->
decode_versions(Versions, []).
%%
decode_versions(<<>>, Acc) ->
lists:reverse(Acc);
decode_versions(<<?BYTE(M),?BYTE(N),Rest/binary>>, Acc) ->
decode_versions(Rest, [{M,N}|Acc]).
decode_next_protocols({next_protocol_negotiation, Protocols}) ->
decode_protocols(Protocols, []).
decode_protocols(<<>>, Acc) ->
lists:reverse(Acc);
decode_protocols(<<?BYTE(Len), Protocol:Len/binary, Rest/binary>>, Acc) ->
case Len of
0 ->
{error, invalid_protocols};
_ ->
decode_protocols(Rest, [Protocol|Acc])
end;
decode_protocols(_Bytes, _Acc) ->
{error, invalid_protocols}.
%% encode/decode stream of certificate data to/from list of certificate data
certs_to_list(ASN1Certs) ->
certs_to_list(ASN1Certs, []).
certs_to_list(<<?UINT24(CertLen), Cert:CertLen/binary, Rest/binary>>, Acc) ->
certs_to_list(Rest, [Cert | Acc]);
certs_to_list(<<>>, Acc) ->
lists:reverse(Acc, []).
certs_from_list(ACList) ->
list_to_binary([begin
CertLen = byte_size(Cert),
<<?UINT24(CertLen), Cert/binary>>
end || Cert <- ACList]).
from_3bytes(Bin3) ->
from_3bytes(Bin3, []).
from_3bytes(<<>>, Acc) ->
lists:reverse(Acc);
from_3bytes(<<?UINT24(N), Rest/binary>>, Acc) ->
from_3bytes(Rest, [?uint16(N) | Acc]).
from_2bytes(Bin2) ->
from_2bytes(Bin2, []).
from_2bytes(<<>>, Acc) ->
lists:reverse(Acc);
from_2bytes(<<?UINT16(N), Rest/binary>>, Acc) ->
from_2bytes(Rest, [?uint16(N) | Acc]).
key_exchange_alg(rsa) ->
?KEY_EXCHANGE_RSA;
key_exchange_alg(Alg) when Alg == dhe_rsa; Alg == dhe_dss;
Alg == dh_dss; Alg == dh_rsa; Alg == dh_anon ->
?KEY_EXCHANGE_DIFFIE_HELLMAN;
key_exchange_alg(Alg) when Alg == ecdhe_rsa; Alg == ecdh_rsa;
Alg == ecdhe_ecdsa; Alg == ecdh_ecdsa;
Alg == ecdh_anon ->
?KEY_EXCHANGE_EC_DIFFIE_HELLMAN;
key_exchange_alg(psk) ->
?KEY_EXCHANGE_PSK;
key_exchange_alg(dhe_psk) ->
?KEY_EXCHANGE_DHE_PSK;
key_exchange_alg(ecdhe_psk) ->
?KEY_EXCHANGE_EC_DIFFIE_HELLMAN_PSK;
key_exchange_alg(rsa_psk) ->
?KEY_EXCHANGE_RSA_PSK;
key_exchange_alg(Alg)
when Alg == srp_rsa; Alg == srp_dss; Alg == srp_anon ->
?KEY_EXCHANGE_SRP;
key_exchange_alg(_) ->
?NULL.
%%-------------Cipher suite handling -----------------------------
select_cipher_suite(CipherSuites, Suites, false) ->
select_cipher_suite(CipherSuites, Suites);
select_cipher_suite(CipherSuites, Suites, true) ->
select_cipher_suite(Suites, CipherSuites).
select_cipher_suite([], _) ->
no_suite;
select_cipher_suite([Suite | ClientSuites], SupportedSuites) ->
case is_member(Suite, SupportedSuites) of
true ->
Suite;
false ->
select_cipher_suite(ClientSuites, SupportedSuites)
end.
is_member(Suite, SupportedSuites) ->
lists:member(Suite, SupportedSuites).
psk_secret(PSKIdentity, PSKLookup) ->
case handle_psk_identity(PSKIdentity, PSKLookup) of
{ok, PSK} when is_binary(PSK) ->
Len = erlang:byte_size(PSK),
<<?UINT16(Len), 0:(Len*8), ?UINT16(Len), PSK/binary>>;
#alert{} = Alert ->
Alert;
_ ->
throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
end.
psk_secret(PSKIdentity, PSKLookup, PremasterSecret) ->
case handle_psk_identity(PSKIdentity, PSKLookup) of
{ok, PSK} when is_binary(PSK) ->
Len = erlang:byte_size(PremasterSecret),
PSKLen = erlang:byte_size(PSK),
<<?UINT16(Len), PremasterSecret/binary, ?UINT16(PSKLen), PSK/binary>>;
#alert{} = Alert ->
Alert;
_ ->
throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
end.
handle_psk_identity(_PSKIdentity, LookupFun)
when LookupFun == undefined ->
error;
handle_psk_identity(PSKIdentity, {Fun, UserState}) ->
Fun(psk, PSKIdentity, UserState).
filter_hashsigns([], [], _, _, Acc) ->
lists:reverse(Acc);
filter_hashsigns([Suite | Suites], [#{key_exchange := KeyExchange} | Algos], HashSigns, Version,
Acc) when KeyExchange == dhe_ecdsa;
KeyExchange == ecdhe_ecdsa ->
do_filter_hashsigns(ecdsa, Suite, Suites, Algos, HashSigns, Version, Acc);
filter_hashsigns([Suite | Suites], [#{key_exchange := KeyExchange} | Algos], HashSigns, Version,
Acc) when KeyExchange == rsa;
KeyExchange == dhe_rsa;
KeyExchange == ecdhe_rsa;
KeyExchange == srp_rsa;
KeyExchange == rsa_psk ->
do_filter_hashsigns(rsa, Suite, Suites, Algos, HashSigns, Version, Acc);
filter_hashsigns([Suite | Suites], [#{key_exchange := KeyExchange} | Algos], HashSigns, Version, Acc) when
KeyExchange == dhe_dss;
KeyExchange == srp_dss ->
do_filter_hashsigns(dsa, Suite, Suites, Algos, HashSigns, Version, Acc);
filter_hashsigns([Suite | Suites], [#{key_exchange := KeyExchange} | Algos], HashSigns, Verion,
Acc) when
KeyExchange == dh_dss;
KeyExchange == dh_rsa;
KeyExchange == dh_ecdsa;
KeyExchange == ecdh_rsa;
KeyExchange == ecdh_ecdsa ->
%% Fixed DH certificates MAY be signed with any hash/signature
%% algorithm pair appearing in the hash_sign extension. The names
%% DH_DSS, DH_RSA, ECDH_ECDSA, and ECDH_RSA are historical.
filter_hashsigns(Suites, Algos, HashSigns, Verion, [Suite| Acc]);
filter_hashsigns([Suite | Suites], [#{key_exchange := KeyExchange} | Algos], HashSigns, Version,
Acc) when
KeyExchange == dh_anon;
KeyExchange == ecdh_anon;
KeyExchange == srp_anon;
KeyExchange == psk;
KeyExchange == dhe_psk;
KeyExchange == ecdhe_psk ->
%% In this case hashsigns is not used as the kexchange is anonaymous
filter_hashsigns(Suites, Algos, HashSigns, Version, [Suite| Acc]).
do_filter_hashsigns(SignAlgo, Suite, Suites, Algos, HashSigns, Version, Acc) ->
case lists:keymember(SignAlgo, 2, HashSigns) of
true ->
filter_hashsigns(Suites, Algos, HashSigns, Version, [Suite| Acc]);
false ->
filter_hashsigns(Suites, Algos, HashSigns, Version, Acc)
end.
filter_unavailable_ecc_suites(no_curve, Suites) ->
ECCSuites = ssl_cipher:filter_suites(Suites, #{key_exchange_filters => [fun(ecdh_ecdsa) -> true;
(ecdhe_ecdsa) -> true;
(ecdh_rsa) -> true;
(_) -> false
end],
cipher_filters => [],
mac_filters => [],
prf_filters => []}),
Suites -- ECCSuites;
filter_unavailable_ecc_suites(_, Suites) ->
Suites.
%%-------------Extension handling --------------------------------
handle_renegotiation_extension(Role, RecordCB, Version, Info, Random, NegotiatedCipherSuite,
ClientCipherSuites, Compression,
ConnectionStates0, Renegotiation, SecureRenegotation) ->
case handle_renegotiation_info(RecordCB, Role, Info, ConnectionStates0,
Renegotiation, SecureRenegotation,
ClientCipherSuites) of
{ok, ConnectionStates} ->
hello_pending_connection_states(RecordCB, Role,
Version,
NegotiatedCipherSuite,
Random,
Compression,
ConnectionStates);
#alert{} = Alert ->
throw(Alert)
end.
%% Receive protocols, choose one from the list, return it.
handle_alpn_extension(_, {error, Reason}) ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, Reason);
handle_alpn_extension([], _) ->
?ALERT_REC(?FATAL, ?NO_APPLICATION_PROTOCOL);
handle_alpn_extension([ServerProtocol|Tail], ClientProtocols) ->
case lists:member(ServerProtocol, ClientProtocols) of
true -> ServerProtocol;
false -> handle_alpn_extension(Tail, ClientProtocols)
end.
handle_next_protocol(undefined,
_NextProtocolSelector, _Renegotiating) ->
undefined;
handle_next_protocol(#next_protocol_negotiation{} = NextProtocols,
NextProtocolSelector, Renegotiating) ->
case next_protocol_extension_allowed(NextProtocolSelector, Renegotiating) of
true ->
select_next_protocol(decode_next_protocols(NextProtocols), NextProtocolSelector);
false ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, unexpected_next_protocol_extension)
end.
handle_next_protocol_extension(NextProtocolNegotiation, Renegotiation, SslOpts)->
case handle_next_protocol_on_server(NextProtocolNegotiation, Renegotiation, SslOpts) of
#alert{} = Alert ->
Alert;
ProtocolsToAdvertise ->
ProtocolsToAdvertise
end.
handle_next_protocol_on_server(undefined, _Renegotiation, _SslOpts) ->
undefined;
handle_next_protocol_on_server(#next_protocol_negotiation{extension_data = <<>>},
false, #ssl_options{next_protocols_advertised = Protocols}) ->
Protocols;
handle_next_protocol_on_server(_Hello, _Renegotiation, _SSLOpts) ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, unexpected_next_protocol_extension).
next_protocol_extension_allowed(NextProtocolSelector, Renegotiating) ->
NextProtocolSelector =/= undefined andalso not Renegotiating.
select_next_protocol({error, Reason}, _NextProtocolSelector) ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, Reason);
select_next_protocol(Protocols, NextProtocolSelector) ->
case NextProtocolSelector(Protocols) of
?NO_PROTOCOL ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, no_next_protocol);
Protocol when is_binary(Protocol) ->
Protocol
end.
handle_srp_extension(undefined, Session) ->
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;
KeyExAlgo == ecdhe_psk;
KeyExAlgo == srp_anon;
KeyExAlgo == dh_anon;
KeyExAlgo == ecdhe_anon
->
true;
is_acceptable_hash_sign(Algos,_, SupportedHashSigns) ->
is_acceptable_hash_sign(Algos, SupportedHashSigns).
is_acceptable_hash_sign(Algos, SupportedHashSigns) ->
lists:member(Algos, SupportedHashSigns).
is_acceptable_cert_type(Sign, _HashSigns, 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).
sign_type(rsa) ->
?RSA_SIGN;
sign_type(dsa) ->
?DSS_SIGN;
sign_type(ecdsa) ->
?ECDSA_SIGN.
server_name(_, _, server) ->
undefined; %% Not interesting to check your own name.
server_name(undefined, Host, client) ->
{fallback, Host}; %% Fallback to Host argument to connect
server_name(SNI, _, client) ->
SNI. %% If Server Name Indication is available
client_ecc_extensions(SupportedECCs) ->
CryptoSupport = proplists:get_value(public_keys, crypto:supports()),
case proplists:get_bool(ecdh, CryptoSupport) of
true ->
EcPointFormats = #ec_point_formats{ec_point_format_list = [?ECPOINT_UNCOMPRESSED]},
EllipticCurves = SupportedECCs,
{EcPointFormats, EllipticCurves};
_ ->
{undefined, undefined}
end.
server_ecc_extension(_Version, EcPointFormats) ->
CryptoSupport = proplists:get_value(public_keys, crypto:supports()),
case proplists:get_bool(ecdh, CryptoSupport) of
true ->
handle_ecc_point_fmt_extension(EcPointFormats);
false ->
undefined
end.
handle_ecc_point_fmt_extension(undefined) ->
undefined;
handle_ecc_point_fmt_extension(_) ->
#ec_point_formats{ec_point_format_list = [?ECPOINT_UNCOMPRESSED]}.
advertises_ec_ciphers([]) ->
false;
advertises_ec_ciphers([#{key_exchange := ecdh_ecdsa} | _]) ->
true;
advertises_ec_ciphers([#{key_exchange := ecdhe_ecdsa} | _]) ->
true;
advertises_ec_ciphers([#{key_exchange := ecdh_rsa} | _]) ->
true;
advertises_ec_ciphers([#{key_exchange := ecdhe_rsa} | _]) ->
true;
advertises_ec_ciphers([#{key_exchange := ecdh_anon} | _]) ->
true;
advertises_ec_ciphers([{ecdhe_psk, _,_,_} | _]) ->
true;
advertises_ec_ciphers([_| Rest]) ->
advertises_ec_ciphers(Rest).
select_shared_curve([], _) ->
no_curve;
select_shared_curve([Curve | Rest], Curves) ->
case lists:member(Curve, Curves) of
true ->
{namedCurve, Curve};
false ->
select_shared_curve(Rest, Curves)
end.
sni(undefined) ->
undefined;
sni(disable) ->
undefined;
sni(Hostname) ->
#sni{hostname = Hostname}.
renegotiation_info(_, client, _, false) ->
#renegotiation_info{renegotiated_connection = undefined};
renegotiation_info(_RecordCB, server, ConnectionStates, false) ->
ConnectionState = ssl_record:current_connection_state(ConnectionStates, read),
case maps:get(secure_renegotiation, ConnectionState) of
true ->
#renegotiation_info{renegotiated_connection = ?byte(0)};
false ->
#renegotiation_info{renegotiated_connection = undefined}
end;
renegotiation_info(_RecordCB, client, ConnectionStates, true) ->
ConnectionState = ssl_record:current_connection_state(ConnectionStates, read),
case maps:get(secure_renegotiation, ConnectionState) of
true ->
Data = maps:get(client_verify_data, ConnectionState),
#renegotiation_info{renegotiated_connection = Data};
false ->
#renegotiation_info{renegotiated_connection = undefined}
end;
renegotiation_info(_RecordCB, server, ConnectionStates, true) ->
ConnectionState = ssl_record:current_connection_state(ConnectionStates, read),
case maps:get(secure_renegotiation, ConnectionState) of
true ->
CData = maps:get(client_verify_data, ConnectionState),
SData = maps:get(server_verify_data, ConnectionState),
#renegotiation_info{renegotiated_connection = <<CData/binary, SData/binary>>};
false ->
#renegotiation_info{renegotiated_connection = undefined}
end.
handle_renegotiation_info(_RecordCB, _, #renegotiation_info{renegotiated_connection = ?byte(0)},
ConnectionStates, false, _, _) ->
{ok, ssl_record:set_renegotiation_flag(true, ConnectionStates)};
handle_renegotiation_info(_RecordCB, server, undefined, ConnectionStates, _, _, CipherSuites) ->
case is_member(?TLS_EMPTY_RENEGOTIATION_INFO_SCSV, CipherSuites) of
true ->
{ok, ssl_record:set_renegotiation_flag(true, ConnectionStates)};
false ->
{ok, ssl_record:set_renegotiation_flag(false, ConnectionStates)}
end;
handle_renegotiation_info(_RecordCB, _, undefined, ConnectionStates, false, _, _) ->
{ok, ssl_record:set_renegotiation_flag(false, ConnectionStates)};
handle_renegotiation_info(_RecordCB, client, #renegotiation_info{renegotiated_connection = ClientServerVerify},
ConnectionStates, true, _, _) ->
ConnectionState = ssl_record:current_connection_state(ConnectionStates, read),
CData = maps:get(client_verify_data, ConnectionState),
SData = maps:get(server_verify_data, ConnectionState),
case <<CData/binary, SData/binary>> == ClientServerVerify of
true ->
{ok, ConnectionStates};
false ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, client_renegotiation)
end;
handle_renegotiation_info(_RecordCB, server, #renegotiation_info{renegotiated_connection = ClientVerify},
ConnectionStates, true, _, CipherSuites) ->
case is_member(?TLS_EMPTY_RENEGOTIATION_INFO_SCSV, CipherSuites) of
true ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, {server_renegotiation, empty_renegotiation_info_scsv});
false ->
ConnectionState = ssl_record:current_connection_state(ConnectionStates, read),
Data = maps:get(client_verify_data, ConnectionState),
case Data == ClientVerify of
true ->
{ok, ConnectionStates};
false ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, server_renegotiation)
end
end;
handle_renegotiation_info(RecordCB, client, undefined, ConnectionStates, true, SecureRenegotation, _) ->
handle_renegotiation_info(RecordCB, ConnectionStates, SecureRenegotation);
handle_renegotiation_info(RecordCB, server, undefined, ConnectionStates, true, SecureRenegotation, CipherSuites) ->
case is_member(?TLS_EMPTY_RENEGOTIATION_INFO_SCSV, CipherSuites) of
true ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, {server_renegotiation, empty_renegotiation_info_scsv});
false ->
handle_renegotiation_info(RecordCB, ConnectionStates, SecureRenegotation)
end.
handle_renegotiation_info(_RecordCB, ConnectionStates, SecureRenegotation) ->
ConnectionState = ssl_record:current_connection_state(ConnectionStates, read),
case {SecureRenegotation, maps:get(secure_renegotiation, ConnectionState)} of
{_, true} ->
?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, already_secure);
{true, false} ->
?ALERT_REC(?FATAL, ?NO_RENEGOTIATION);
{false, false} ->
{ok, ConnectionStates}
end.
cert_curve(_, _, no_suite) ->
{no_curve, no_suite};
cert_curve(Cert, ECCCurve0, CipherSuite) ->
case ssl_cipher_format:suite_definition(CipherSuite) of
#{key_exchange := Kex} when Kex == ecdh_ecdsa;
Kex == ecdh_rsa ->
OtpCert = public_key:pkix_decode_cert(Cert, otp),
TBSCert = OtpCert#'OTPCertificate'.tbsCertificate,
#'OTPSubjectPublicKeyInfo'{algorithm = AlgInfo}
= TBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo,
{namedCurve, Oid} = AlgInfo#'PublicKeyAlgorithm'.parameters,
{{namedCurve, Oid}, 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() ->
#{}.