enoise/src/enoise_hs_state.erl
Hans Svensson acd92fdbc0 Ditch enacl, support DH448 and Blake2s, and fix types (#14)
* Remove get_stacktrace (deprecated since OTP-24)

* Add DH448 support and switch to crypto:generate_key for DH25519

* Switch to crypto:hash/2 for Blake2b and support Blake2s

* Switch last enacl calls to crypto - no more enacl

* Eqwalizer fixes

Ewqalizer fix

Eqwalizer fix

Eqwalizer fix

Eqwalizer fix

Eqwalizer support

Eqwalizer fix

Fix tests to follow types (remote keys)

* More error handling on setup

* Dialyzer fix

* Write CHANGELOG

* Note about type-checking in README
2025-03-28 10:12:35 +01:00

200 lines
7.7 KiB
Erlang

%%% ------------------------------------------------------------------
%%% @copyright 2018, Aeternity Anstalt
%%%
%%% @doc Module encapsulating a Noise handshake state
%%%
%%% @end
%%% ------------------------------------------------------------------
-module(enoise_hs_state).
-export([ finalize/1
, init/4
, next_message/1
, read_message/2
, remote_keys/1
, write_message/2]).
-include("enoise.hrl").
-type noise_role() :: initiator | responder.
-type noise_dh() :: dh25519 | dh448.
-type noise_token() :: s | e | ee | ss | es | se.
-type keypair() :: enoise_keypair:keypair().
-type noise_split_state() :: #{ rx := enoise_cipher_state:state(),
tx := enoise_cipher_state:state(),
hs_hash := binary(),
final_state => state() }.
-type optional_key() :: undefined | keypair().
-type initial_keys() :: {optional_key(), optional_key(), optional_key(), optional_key()}.
-record(noise_hs, { ss :: enoise_sym_state:state()
, s :: keypair() | undefined
, e :: keypair() | undefined
, rs :: keypair() | undefined
, re :: keypair() | undefined
, role = initiator :: noise_role()
, dh = dh25519 :: noise_dh()
, msgs = [] :: [enoise_protocol:noise_msg()] }).
-opaque state() :: #noise_hs{}.
-export_type([noise_dh/0, noise_role/0, noise_split_state/0, noise_token/0, state/0]).
-spec init(Protocol :: enoise_protocol:protocol(), Role :: noise_role(),
Prologue :: binary(), Keys :: initial_keys()) -> {ok, state()} | {error, term()}.
init(Protocol, Role, Prologue, {S, E, RS, RE}) ->
SS0 = enoise_sym_state:init(Protocol),
SS1 = enoise_sym_state:mix_hash(SS0, Prologue),
HS = #noise_hs{ ss = SS1
, s = S, e = E, rs = RS, re = RE
, role = Role
, dh = enoise_protocol:dh(Protocol)
, msgs = enoise_protocol:msgs(Role, Protocol) },
PreMsgs = enoise_protocol:pre_msgs(Role, Protocol),
pre_mix(PreMsgs, HS).
pre_mix([], HS) -> {ok, HS};
pre_mix([{out, [s]} | Msgs], HS = #noise_hs{ s = S }) when S /= undefined ->
pre_mix(Msgs, mix_hash(HS, enoise_keypair:pubkey(S)));
pre_mix([{out, [e]} | Msgs], HS = #noise_hs{ e = E }) when E /= undefined ->
pre_mix(Msgs, mix_hash(HS, enoise_keypair:pubkey(E)));
pre_mix([{in, [s]} | Msgs], HS = #noise_hs{ rs = RS }) when RS /= undefined ->
pre_mix(Msgs, mix_hash(HS, enoise_keypair:pubkey(RS)));
pre_mix([{in, [e]} | Msgs], HS = #noise_hs{ re = RE }) when RE /= undefined ->
pre_mix(Msgs, mix_hash(HS, enoise_keypair:pubkey(RE)));
pre_mix(_Msg, _HS) ->
{error, invalid_noise_setup}.
-spec finalize(HS :: state()) -> {ok, noise_split_state()} | {error, term()}.
finalize(HS = #noise_hs{ msgs = [], ss = SS, role = Role }) ->
{C1, C2} = enoise_sym_state:split(SS),
HSHash = enoise_sym_state:h(SS),
Final = #{ hs_hash => HSHash, final_state => HS },
case Role of
initiator -> {ok, Final#{ tx => C1, rx => C2 }};
responder -> {ok, Final#{ rx => C1, tx => C2 }}
end;
finalize(_) ->
error({bad_state, finalize}).
-spec next_message(HS :: state()) -> in | out | done.
next_message(#noise_hs{ msgs = [{Dir, _} | _] }) -> Dir;
next_message(#noise_hs{ }) -> done.
-spec write_message(HS :: state(), PayLoad :: binary()) -> {ok, state(), binary()}.
write_message(HS = #noise_hs{ msgs = [{out, Msg} | Msgs] }, PayLoad) ->
{HS1, MsgBuf1} = write_message(HS#noise_hs{ msgs = Msgs }, Msg, <<>>),
{ok, HS2, MsgBuf2} = encrypt_and_hash(HS1, PayLoad),
MsgBuf = <<MsgBuf1/binary, MsgBuf2/binary>>,
{ok, HS2, MsgBuf}.
-spec read_message(HS :: state(), Message :: binary()) ->
{ok, state(), binary()} | {error, term()}.
read_message(HS = #noise_hs{ msgs = [{in, Msg} | Msgs] }, Message) ->
case read_message(HS#noise_hs{ msgs = Msgs }, Msg, Message) of
{ok, HS1, RestBuf1} -> decrypt_and_hash(HS1, RestBuf1);
Err = {error, _} -> Err
end.
-spec remote_keys(HS :: state()) -> undefined | keypair().
remote_keys(#noise_hs{ rs = RS }) ->
RS.
write_message(HS, [], MsgBuf) ->
{HS, MsgBuf};
write_message(HS, [Token | Tokens], MsgBuf0) ->
{HS1, MsgBuf1} = write_token(HS, Token),
write_message(HS1, Tokens, <<MsgBuf0/binary, MsgBuf1/binary>>).
read_message(HS, [], Data) ->
{ok, HS, Data};
read_message(HS, [Token | Tokens], Data0) ->
case read_token(HS, Token, Data0) of
{ok, HS1, Data1} -> read_message(HS1, Tokens, Data1);
Err = {error, _} -> Err
end.
write_token(HS = #noise_hs{ e = undefined }, e) ->
E = new_key_pair(HS),
PubE = enoise_keypair:pubkey(E),
{mix_hash(HS#noise_hs{ e = E }, PubE), PubE};
%% Should only apply during test - TODO: secure this
write_token(HS = #noise_hs{ e = E }, e) ->
PubE = enoise_keypair:pubkey(E),
{mix_hash(HS, PubE), PubE};
write_token(HS = #noise_hs{ s = S }, s) ->
{ok, HS1, Msg} = encrypt_and_hash(HS, enoise_keypair:pubkey(S)),
{HS1, Msg};
write_token(HS, Token) ->
{K1, K2} = dh_token(HS, Token),
{mix_key(HS, dh(HS, K1, K2)), <<>>}.
read_token(HS = #noise_hs{ re = undefined, dh = DH }, e, Data0) ->
DHLen = enoise_crypto:dhlen(DH),
case Data0 of
<<REPub:DHLen/binary, Data1/binary>> ->
RE = enoise_keypair:new(DH, REPub),
{ok, mix_hash(HS#noise_hs{ re = RE }, REPub), Data1};
_ ->
{error, {bad_data, {failed_to_read_token, e, DHLen}}}
end;
read_token(HS = #noise_hs{ rs = undefined, dh = DH }, s, Data0) ->
DHLen = case has_key(HS) of
true -> enoise_crypto:dhlen(DH) + 16;
false -> enoise_crypto:dhlen(DH)
end,
case Data0 of
<<Temp:DHLen/binary, Data1/binary>> ->
case decrypt_and_hash(HS, Temp) of
{ok, HS1, RSPub} ->
RS = enoise_keypair:new(DH, RSPub),
{ok, HS1#noise_hs{ rs = RS }, Data1};
Err = {error, _} ->
Err
end;
_ ->
{error, {bad_data, {failed_to_read_token, s, DHLen}}}
end;
read_token(HS, Token, Data) ->
{K1, K2} = dh_token(HS, Token),
{ok, mix_key(HS, dh(HS, K1, K2)), Data}.
dh_token(#noise_hs{ e = E, re = RE } , ee) -> {E, RE};
dh_token(#noise_hs{ e = E, rs = RS, role = initiator }, es) -> {E, RS};
dh_token(#noise_hs{ s = S, re = RE, role = responder }, es) -> {S, RE};
dh_token(#noise_hs{ s = S, re = RE, role = initiator }, se) -> {S, RE};
dh_token(#noise_hs{ e = E, rs = RS, role = responder }, se) -> {E, RS};
dh_token(#noise_hs{ s = S, rs = RS } , ss) -> {S, RS}.
%% Local wrappers
new_key_pair(#noise_hs{ dh = DH }) ->
enoise_keypair:new(DH).
dh(#noise_hs{ dh = DH }, Key1, Key2) ->
enoise_crypto:dh(DH, Key1, Key2).
has_key(#noise_hs{ ss = SS }) ->
CS = enoise_sym_state:cipher_state(SS),
enoise_cipher_state:has_key(CS).
mix_key(HS = #noise_hs{ ss = SS0 }, Data) ->
HS#noise_hs{ ss = enoise_sym_state:mix_key(SS0, Data) }.
mix_hash(HS = #noise_hs{ ss = SS0 }, Data) ->
HS#noise_hs{ ss = enoise_sym_state:mix_hash(SS0, Data) }.
encrypt_and_hash(HS = #noise_hs{ ss = SS0 }, PlainText) ->
{ok, SS1, CipherText} = enoise_sym_state:encrypt_and_hash(SS0, PlainText),
{ok, HS#noise_hs{ ss = SS1 }, CipherText}.
decrypt_and_hash(HS = #noise_hs{ ss = SS0 }, CipherText) ->
case enoise_sym_state:decrypt_and_hash(SS0, CipherText) of
{ok, SS1, PlainText} ->
{ok, HS#noise_hs{ ss = SS1 }, PlainText};
{error, Reason} ->
{error, Reason}
end.