Remove PBC based cryptography

fixes #70
helium · Jul 1, 2021 · d558860 · d558860
1 parent db7af6a
commit d558860
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diff --git a/rebar.config b/rebar.config
@@ -4,7 +4,6 @@
 {cover_enabled, true}.
 {deps, [
         {erlang_tc, ".*", {git, "https://github.com/helium/erlang-tc.git", {branch, "main"}}},
-        {erlang_tpke, ".*", {git, "https://github.com/helium/erlang-tpke.git", {branch, "master"}}},
         {erasure, {git, "https://github.com/helium/erlang-erasure.git", {branch, "master"}}},
         {merkerl, "1.0.1"}
        ]}.

diff --git a/rebar.lock b/rebar.lock
@@ -3,18 +3,10 @@
   {git,"https://github.com/helium/erlang-erasure.git",
        {ref,"c73354ca9914225a825569693dc72db6691d91f1"}},
   0},
- {<<"erlang_pbc">>,
-  {git,"https://github.com/helium/erlang_pbc.git",
-       {ref,"1d2651ba01ba81b748c553d9f729c0e167eeab72"}},
-  1},
  {<<"erlang_tc">>,
   {git,"https://github.com/helium/erlang-tc.git",
        {ref,"b3ef1d5541586f5c85b6d231345a921d57be32a3"}},
   0},
- {<<"erlang_tpke">>,
-  {git,"https://github.com/helium/erlang-tpke.git",
-       {ref,"02e955cd16ca31519b1b9aaf46cf98ddc406b469"}},
-  0},
  {<<"merkerl">>,{pkg,<<"merkerl">>,<<"1.0.1">>},0}]}.
 [
 {pkg_hash,[

diff --git a/src/hbbft.app.src b/src/hbbft.app.src
@@ -7,7 +7,6 @@
     stdlib,
     merkerl,
     erlang_tc,
-    erlang_tpke,
     erasure
    ]},
   {env,[]},

diff --git a/src/hbbft.erl b/src/hbbft.erl
diff --git a/src/hbbft_cc.erl b/src/hbbft_cc.erl
@@ -4,9 +4,9 @@
 
 -record(cc_data, {
           state = waiting :: waiting | done,
-          sk :: tc_key_share:tc_key_share() | tpke_privkey:privkey(),
+          sk :: tc_key_share:tc_key_share(),
           %% Note: sid is assumed to be a unique nonce that serves as name of this common coin
-          sid :: binary() | erlang_pbc:element(),
+          sid :: binary(),
           n :: pos_integer(),
           f :: non_neg_integer(),
           shares = maps:new() :: #{non_neg_integer() => {non_neg_integer(), tc_signature_share:sig_share()}}
@@ -45,13 +45,8 @@ status(CCData) ->
            binary(),
            pos_integer(),
            non_neg_integer()) -> cc_data().
-init(KeyShare, Sid0, N, F) ->
-    Sid = case tc_key_share:is_key_share(KeyShare) of
-              true ->
-                  Sid0;
-              false ->
-                  tpke_pubkey:hash_message(tpke_privkey:public_key(KeyShare), Sid0)
-          end,
+init(KeyShare, Sid, N, F) ->
+    true = tc_key_share:is_key_share(KeyShare),
     #cc_data{sk=KeyShare, n=N, f=F, sid=Sid}.
 
 %% Figure12. Bullet2
@@ -60,15 +55,9 @@ init(KeyShare, Sid0, N, F) ->
 get_coin(Data = #cc_data{state=done}) ->
     {Data, ok};
 get_coin(Data = #cc_data{sk=SK}) ->
-    case hbbft_utils:curve(SK) of
-        'BLS12-381' ->
-            Share = tc_key_share:sign_share(Data#cc_data.sk, Data#cc_data.sid),
-            {Data, {send, [{multicast, {share, hbbft_utils:sig_share_to_binary('BLS12-381', Share)}}]}};
-        'SS512' ->
-            Share = tpke_privkey:sign(Data#cc_data.sk, Data#cc_data.sid),
-            SerializedShare = hbbft_utils:sig_share_to_binary('SS512', Share),
-            {Data, {send, [{multicast, {share, SerializedShare}}]}}
-    end.
+    'BLS12-381' = hbbft_utils:curve(SK),
+    Share = tc_key_share:sign_share(Data#cc_data.sk, Data#cc_data.sid),
+    {Data, {send, [{multicast, {share, hbbft_utils:sig_share_to_binary('BLS12-381', Share)}}]}}.
 
 
 %% upon receiving at least f + 1 shares, attempt to combine them
@@ -87,16 +76,14 @@ share(#cc_data{state=done}, _J, _Share) ->
 share(Data=#cc_data{sk=SK}, J, Share) ->
     case maps:is_key(J, Data#cc_data.shares) of
         false ->
-            Curve = hbbft_utils:curve(SK),
+            Curve = 'BLS12-381' = hbbft_utils:curve(SK),
             DeserializedShare = hbbft_utils:binary_to_sig_share(Curve, SK, Share),
-            ValidShare = case Curve of
-                             'BLS12-381' ->
-                                 tc_key_share:verify_signature_share(Data#cc_data.sk,
-                                                                          DeserializedShare,
-                                                                          Data#cc_data.sid);
-                             'SS512' ->
-                                 tpke_pubkey:verify_signature_share(tpke_privkey:public_key(Data#cc_data.sk), DeserializedShare, Data#cc_data.sid)
-                         end,
+            ValidShare =
+                tc_key_share:verify_signature_share(
+                    Data#cc_data.sk,
+                    DeserializedShare,
+                    Data#cc_data.sid
+                ),
             case ValidShare of
                 true ->
                     %% store the deserialized share in the shares map, convenient to use later to verify signature
@@ -105,26 +92,23 @@ share(Data=#cc_data{sk=SK}, J, Share) ->
                     case maps:size(NewData#cc_data.shares) > Data#cc_data.f of
                         true ->
                             %% combine shares
-                            {ok, Sig} = case Curve of
-                                            'BLS12-381' ->
-                                                tc_key_share:combine_signature_shares(SK, maps:values(NewData#cc_data.shares));
-                                            'SS512' ->
-                                                tpke_pubkey:combine_verified_signature_shares(tpke_privkey:public_key(NewData#cc_data.sk), maps:values(NewData#cc_data.shares))
-                                        end,
+                            'BLS12-381' = Curve,
+                            {ok, Sig} =
+                                tc_key_share:combine_signature_shares(
+                                    SK,
+                                    maps:values(NewData#cc_data.shares)
+                                ),
                             %% check if the signature is valid
-                            ValidSignature = case Curve of
-                                                 'BLS12-381' ->
-                                                     tc_key_share:verify(NewData#cc_data.sk, Sig, NewData#cc_data.sid);
-                                                 'SS512' ->
-                                                     tpke_pubkey:verify_signature(tpke_privkey:public_key(NewData#cc_data.sk), Sig, NewData#cc_data.sid)
-                                             end,
-                            case ValidSignature of
+                            case
+                                tc_key_share:verify(
+                                    NewData#cc_data.sk,
+                                    Sig,
+                                    NewData#cc_data.sid
+                                )
+                            of
                                 true ->
                                     %% TODO do something better here!
-                                    <<Val:32/integer, _/binary>> = case Curve of
-                                                                       'BLS12-381' -> tc_signature:serialize(Sig);
-                                                                       'SS512' -> erlang_pbc:element_to_binary(Sig)
-                                                                   end,
+                                    <<Val:32/integer, _/binary>> = tc_signature:serialize(Sig),
                                     {NewData#cc_data{state=done}, {result, Val}};
                                 false ->
                                     {NewData, ok}
@@ -150,7 +134,7 @@ serialize(#cc_data{state = State, sid = SID, n = N, sk = SK, f = F, shares = Sha
         shares = serialize_shares(hbbft_utils:curve(SK), Shares)
     }.
 
--spec deserialize(cc_serialized_data(), tc_key_share:tc_key_share() | tpke_privkey:privkey()) ->
+-spec deserialize(cc_serialized_data(), tc_key_share:tc_key_share()) ->
     cc_data().
 deserialize(#cc_serialized_data{state = State, sid = SID, n = N, f = F, shares = Shares}, SK) ->
     #cc_data{
@@ -162,22 +146,17 @@ deserialize(#cc_serialized_data{state = State, sid = SID, n = N, f = F, shares =
         shares = deserialize_shares(hbbft_utils:curve(SK), SK, Shares)
     }.
 
--spec serialize_shares('BLS12-381' | 'SS512', #{non_neg_integer() => tc_signature_share:sig_share()}) -> #{non_neg_integer() => binary()}.
+-spec serialize_shares('BLS12-381', #{non_neg_integer() => tc_signature_share:sig_share()}) -> #{non_neg_integer() => binary()}.
 serialize_shares(Curve, Shares) ->
     maps:map(fun(_K, V) -> hbbft_utils:sig_share_to_binary(Curve, V) end, Shares).
 
--spec deserialize_shares('BLS12-381' | 'SS512', tc_key_share:tc_key_share() | tpke_privkey:privkey(), #{non_neg_integer() => binary()}) -> #{non_neg_integer() => tc_signature_share:sig_share()}.
+-spec deserialize_shares('BLS12-381', tc_key_share:tc_key_share(), #{non_neg_integer() => binary()}) -> #{non_neg_integer() => tc_signature_share:sig_share()}.
 deserialize_shares(Curve, SK, Shares) ->
     maps:map(fun(_K, V) -> hbbft_utils:binary_to_sig_share(Curve, SK, V) end, Shares).
 
-serialize_sid(SID) when is_binary(SID) ->
-    SID;
-serialize_sid(SID) ->
-    erlang_pbc:element_to_binary(SID).
+serialize_sid(<<SID/binary>>) ->
+    SID.
 
 deserialize_sid(SK, SID) ->
-    case hbbft_utils:curve(SK) of
-        'BLS12-381' -> SID;
-        'SS512' -> tpke_pubkey:deserialize_element(tpke_privkey:public_key(SK), SID)
-    end.
-
+    'BLS12-381' = hbbft_utils:curve(SK),
+    SID.
diff --git a/src/hbbft_utils.erl b/src/hbbft_utils.erl
@@ -19,33 +19,20 @@
 sig_share_to_binary('BLS12-381', {ShareIdx, SigShare}) ->
     %% Assume less than 256 members in the consensus group
     ShareBinary = tc_signature_share:serialize(SigShare),
-    <<ShareIdx:8/integer-unsigned, ShareBinary/binary>>;
-sig_share_to_binary('SS512', {ShareIdx, SigShare}) ->
-    ShareBinary = erlang_pbc:element_to_binary(SigShare),
     <<ShareIdx:8/integer-unsigned, ShareBinary/binary>>.
 
 binary_to_sig_share('BLS12-381', _SK, <<ShareIdx:8/integer-unsigned, ShareBinary/binary>>) ->
     SigShare = tc_signature_share:deserialize(ShareBinary),
-    {ShareIdx, SigShare};
-binary_to_sig_share('SS512', SK, <<ShareIdx:8/integer-unsigned, ShareBinary/binary>>) ->
-    ShareElement = tpke_pubkey:deserialize_element(tpke_privkey:public_key(SK), ShareBinary),
-    {ShareIdx, ShareElement}.
+    {ShareIdx, SigShare}.
 
 dec_share_to_binary('BLS12-381', {ShareIdx, DecShare}) ->
     %% Assume less than 256 members in the consensus group
     ShareBinary = tc_decryption_share:serialize(DecShare),
-    <<ShareIdx:8/integer-unsigned, ShareBinary/binary>>;
-dec_share_to_binary('SS512', {ShareIdx, DecShare}) ->
-    %% Assume less than 256 members in the consensus group
-    ShareBinary = erlang_pbc:element_to_binary(DecShare),
     <<ShareIdx:8/integer-unsigned, ShareBinary/binary>>.
 
 binary_to_dec_share('BLS12-381', _SK, <<ShareIdx:8/integer-unsigned, ShareBinary/binary>>) ->
     DecShare = tc_decryption_share:deserialize(ShareBinary),
-    {ShareIdx, DecShare};
-binary_to_dec_share('SS512', SK, <<ShareIdx:8/integer-unsigned, ShareBinary/binary>>) ->
-    ShareElement = tpke_pubkey:deserialize_element(tpke_privkey:public_key(SK), ShareBinary),
-    {ShareIdx, ShareElement}.
+    {ShareIdx, DecShare}.
 
 %% wrap a subprotocol's outbound messages with a protocol identifier
 -spec wrap(Tag :: atom() | {atom(), non_neg_integer()}, [{multicast, Msg :: any()} | {unicast, non_neg_integer(),  Msg :: any()}]) -> [{multicast, {Tag, Msg}} | {unicast, non_neg_integer(), {Tag, Msg}}].
@@ -66,9 +53,5 @@ shuffle(List) ->
 
 -spec curve(KeyShare :: hbbft:key_share()) -> hbbft:curve().
 curve(KeyShare) ->
-    case tc_key_share:is_key_share(KeyShare) of
-        true ->
-            'BLS12-381';
-        false ->
-            'SS512'
-    end.
+    true = tc_key_share:is_key_share(KeyShare),
+    'BLS12-381'.
diff --git a/test/hbbft_SUITE.erl b/test/hbbft_SUITE.erl
@@ -21,7 +21,7 @@
 ]).
 
 all() ->
-    [{group, ss512}, {group, bls12_381}].
+    [{group, bls12_381}].
 
 test_cases() ->
     [
@@ -40,11 +40,8 @@ test_cases() ->
     ].
 
 groups() ->
-    [{ss512, [], test_cases() -- [batch_size_limit_minimal_test]},
-     {bls12_381, [], test_cases()}].
+    [{bls12_381, [], test_cases()}].
 
-init_per_group(ss512, Config) ->
-    [{curve, 'SS512'} | Config];
 init_per_group(bls12_381, Config) ->
     [{curve, 'BLS12-381'} | Config].
 
@@ -56,13 +53,7 @@ init_per_testcase(_, Config) ->
     F = N div 4,
     Module = hbbft,
     BatchSize = 20,
-    case proplists:get_value(curve, Config, 'BLS12-381') of
-        'BLS12-381' ->
-            PrivateKeys = tc_key_share:deal(N, F);
-        'SS512' ->
-            {ok, Dealer} = dealer:new(N, F+1, 'SS512'),
-            {ok, {_PubKey, PrivateKeys}} = dealer:deal(Dealer)
-    end,
+    PrivateKeys = tc_key_share:deal(N, F),
     [{n, N}, {f, F}, {batchsize, BatchSize}, {module, Module}, {privatekeys, PrivateKeys} | Config].
 
 end_per_testcase(_, _Config) ->
@@ -282,23 +273,12 @@ two_actors_missing_test(Config) ->
     ok.
 
 encrypt_decrypt_test(Config) ->
-    case proplists:get_value(curve, Config, 'BLS12-381') of
-        'BLS12-381' ->
-            PrivateKeys = [SK1 | _RemainingSKs] = proplists:get_value(privatekeys, Config),
-            PlainText = crypto:strong_rand_bytes(24),
-            Ciphertext = tc_ciphertext:deserialize(hbbft:encrypt('BLS12-381', hd(PrivateKeys), PlainText)),
-            DecShares = [tc_key_share:decrypt_share(SK, Ciphertext) || SK <- PrivateKeys],
-            {ok, Decrypted} = tc_key_share:combine_decryption_shares(SK1, DecShares, Ciphertext),
-            ?assertEqual(PlainText, Decrypted);
-        'SS512' ->
-            PrivateKeys = proplists:get_value(privatekeys, Config),
-            PubKey = tpke_privkey:public_key(hd(PrivateKeys)),
-            PlainText = crypto:strong_rand_bytes(24),
-            Enc = hbbft:encrypt('SS512', hd(PrivateKeys), PlainText),
-            {ok, EncKey} = hbbft:get_encrypted_key(hd(PrivateKeys), Enc),
-            DecKey = tpke_pubkey:combine_shares(PubKey, EncKey, [ tpke_privkey:decrypt_share(SK, EncKey) || SK <- PrivateKeys]),
-            ?assertEqual(PlainText, hbbft:decrypt(DecKey, Enc))
-    end,
+    PrivateKeys = [SK1 | _RemainingSKs] = proplists:get_value(privatekeys, Config),
+    PlainText = crypto:strong_rand_bytes(24),
+    Ciphertext = tc_ciphertext:deserialize(hbbft:encrypt('BLS12-381', hd(PrivateKeys), PlainText)),
+    DecShares = [tc_key_share:decrypt_share(SK, Ciphertext) || SK <- PrivateKeys],
+    {ok, Decrypted} = tc_key_share:combine_decryption_shares(SK1, DecShares, Ciphertext),
+    ?assertEqual(PlainText, Decrypted),
     ok.
 
 start_on_demand_test(Config) ->
@@ -357,13 +337,7 @@ one_actor_wrong_key_test(Config) ->
     Curve = proplists:get_value(curve, Config),
     BatchSize = proplists:get_value(batchsize, Config),
     PrivateKeys0 = proplists:get_value(privatekeys, Config),
-    case Curve of
-        'BLS12-381' ->
-            PrivateKeys1 = tc_key_share:deal(N, F);
-        'SS512' ->
-            {ok, Dealer} = dealer:new(N, F+1, 'SS512'),
-            {ok, {_PubKey, PrivateKeys1}} = dealer:deal(Dealer)
-    end,
+    PrivateKeys1 = tc_key_share:deal(N, F),
     %% give actor 1 a completely unrelated key
     %% this will prevent it from doing any valid threshold cryptography
     %% and thus it will not be able to reach consensus
@@ -416,11 +390,8 @@ one_actor_corrupted_key_test(Config) ->
     %% this will not prevent the actor for encrypting their bundle
     %% merely prevent it producing valid decryption shares
     %% thus all the actors will be able to converge
-    {Pos, Val} = case Curve of
-              'BLS12-381' -> {4, element(4, PK1) + 1000};
-              'SS512' -> {3, erlang_pbc:element_random(element(3, PK1))}
-          end,
-    PK2 = setelement(Pos, PK1, Val),
+    Pos = 4,
+    PK2 = setelement(Pos, PK1, element(Pos, PK1) + 1000),
     PrivateKeys = [PK2 | PrivateKeys0],
 
     Workers = [