From 4f5f693bf4ece8c102a2f2f10c8d4693d2957a60 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Dimitrov?= <peterdmv@erlang.org>
Date: Fri, 14 Dec 2018 13:20:14 +0100
Subject: ssl: Add support for x25519 and x448 in ECDH

Change-Id: I206b851fc616c53475f4a2935f6f52baf8f3e1e6
---
 lib/ssl/src/ssl_cipher.erl         | 15 +++++++++------
 lib/ssl/src/tls_connection_1_3.erl |  9 +++++++--
 lib/ssl/src/tls_v1.erl             | 24 +++++++++++++++++-------
 3 files changed, 33 insertions(+), 15 deletions(-)

(limited to 'lib')

diff --git a/lib/ssl/src/ssl_cipher.erl b/lib/ssl/src/ssl_cipher.erl
index 0628299d98..46885130d3 100644
--- a/lib/ssl/src/ssl_cipher.erl
+++ b/lib/ssl/src/ssl_cipher.erl
@@ -681,10 +681,9 @@ hash_size(sha) ->
 hash_size(sha256) ->
     32;
 hash_size(sha384) ->
-    48.
-%% Uncomment when adding cipher suite that needs it
-%hash_size(sha512) ->
-%    64.
+    48;
+hash_size(sha512) ->
+    64.
 
 %%--------------------------------------------------------------------
 %%% Internal functions
@@ -888,8 +887,8 @@ scheme_to_components(ecdsa_secp521r1_sha512) -> {sha512, ecdsa, secp521r1};
 scheme_to_components(rsa_pss_rsae_sha256) -> {sha256, rsa_pss_rsae, undefined};
 scheme_to_components(rsa_pss_rsae_sha384) -> {sha384, rsa_pss_rsae, undefined};
 scheme_to_components(rsa_pss_rsae_sha512) -> {sha512, rsa_pss_rsae, undefined};
-%% scheme_to_components(ed25519) -> {undefined, undefined, undefined};
-%% scheme_to_components(ed448) -> {undefined, undefined, undefined};
+scheme_to_components(ed25519) -> {undefined, undefined, undefined};
+scheme_to_components(ed448) -> {undefined, undefined, undefined};
 scheme_to_components(rsa_pss_pss_sha256) -> {sha256, rsa_pss_pss, undefined};
 scheme_to_components(rsa_pss_pss_sha384) -> {sha384, rsa_pss_pss, undefined};
 scheme_to_components(rsa_pss_pss_sha512) -> {sha512, rsa_pss_pss, undefined};
@@ -1231,6 +1230,10 @@ generate_key_exchange(secp384r1) ->
     public_key:generate_key({namedCurve, secp384r1});
 generate_key_exchange(secp521r1) ->
     public_key:generate_key({namedCurve, secp521r1});
+generate_key_exchange(x25519) ->
+    crypto:generate_key(ecdh, x25519);
+generate_key_exchange(x448) ->
+    crypto:generate_key(ecdh, x448);
 generate_key_exchange(FFDHE) ->
     public_key:generate_key(ssl_dh_groups:dh_params(FFDHE)).
 
diff --git a/lib/ssl/src/tls_connection_1_3.erl b/lib/ssl/src/tls_connection_1_3.erl
index 42ae784222..4795ade2a1 100644
--- a/lib/ssl/src/tls_connection_1_3.erl
+++ b/lib/ssl/src/tls_connection_1_3.erl
@@ -269,14 +269,19 @@ get_private_key(#key_share_entry{
     PrivateKey.
 
 
-%% DH
+%% X25519, X448
+calculate_shared_secret(OthersKey, MyKey, Group)
+  when is_binary(OthersKey) andalso is_binary(MyKey) andalso
+       (Group =:= x25519 orelse Group =:= x448)->
+    crypto:compute_key(ecdh, OthersKey, MyKey, Group);
+%% FFDHE
 calculate_shared_secret(OthersKey, MyKey, Group)
   when is_binary(OthersKey) andalso is_binary(MyKey) ->
     Params = #'DHParameter'{prime = P} = ssl_dh_groups:dh_params(Group),
     S = public_key:compute_key(OthersKey, MyKey, Params),
     Size = byte_size(binary:encode_unsigned(P)),
     ssl_cipher:add_zero_padding(S, Size);
-%% ECDH
+%% ECDHE
 calculate_shared_secret(OthersKey, MyKey = #'ECPrivateKey'{}, _Group)
   when is_binary(OthersKey) ->
     Point = #'ECPoint'{point = OthersKey},
diff --git a/lib/ssl/src/tls_v1.erl b/lib/ssl/src/tls_v1.erl
index 16b24c4a5d..df2a421bce 100644
--- a/lib/ssl/src/tls_v1.erl
+++ b/lib/ssl/src/tls_v1.erl
@@ -747,7 +747,9 @@ ecc_curves(_Minor, TLSCurves) ->
 
 -spec groups(4 | all | default) -> [group()].
 groups(all) ->
-    [secp256r1,
+    [x25519,
+     x448,
+     secp256r1,
      secp384r1,
      secp521r1,
      ffdhe2048,
@@ -756,27 +758,33 @@ groups(all) ->
      ffdhe6144,
      ffdhe8192];
 groups(default) ->
-    [secp256r1,
-     secp384r1,
-     secp521r1,
-     ffdhe2048];
+    [x25519,
+     x448,
+     secp256r1,
+     secp384r1];
 groups(Minor) ->
     TLSGroups = groups(all),
     groups(Minor, TLSGroups).
 %%
 -spec groups(4, [group()]) -> [group()].
 groups(_Minor, TLSGroups) ->
-    %% TODO: Adding FFDHE groups to crypto?
-    CryptoGroups = crypto:ec_curves() ++ [ffdhe2048,ffdhe3072,ffdhe4096,ffdhe6144,ffdhe8192],
+    CryptoGroups = supported_groups(),
     lists:filter(fun(Group) -> proplists:get_bool(Group, CryptoGroups) end, TLSGroups).
 
 default_groups(Minor) ->
     TLSGroups = groups(default),
     groups(Minor, TLSGroups).
 
+supported_groups() ->
+    %% TODO: Add new function to crypto?
+    proplists:get_value(curves,  crypto:supports()) ++
+        [ffdhe2048,ffdhe3072,ffdhe4096,ffdhe6144,ffdhe8192].
+
 group_to_enum(secp256r1) -> 23;
 group_to_enum(secp384r1) -> 24;
 group_to_enum(secp521r1) -> 25;
+group_to_enum(x25519)    -> 29;
+group_to_enum(x448)      -> 30;
 group_to_enum(ffdhe2048) -> 256;
 group_to_enum(ffdhe3072) -> 257;
 group_to_enum(ffdhe4096) -> 258;
@@ -786,6 +794,8 @@ group_to_enum(ffdhe8192) -> 260.
 enum_to_group(23) -> secp256r1;
 enum_to_group(24) -> secp384r1;
 enum_to_group(25) -> secp521r1;
+enum_to_group(29) -> x25519;
+enum_to_group(30) -> x448;
 enum_to_group(256) -> ffdhe2048;
 enum_to_group(257) -> ffdhe3072;
 enum_to_group(258) -> ffdhe4096;
-- 
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