ssl: Change defaults for "supported_groups"

Removed strongest Diffie-Hellman groups from defaults (ffdhe3072,
ffdhe4096, ffdhe6144, ffdhe8192) in order to reduce the time spent
with calculating the keys for the key_share extension.

Change-Id: I1cc1914ea4c5093f694989b0153c1bd1c8840eef

1 files changed, 10 insertions, 1 deletions

diff --git a/lib/ssl/src/tls_v1.erl b/lib/ssl/src/tls_v1.erl
index 68ba598612..5665f5310e 100644
--- a/lib/ssl/src/tls_v1.erl
+++ b/lib/ssl/src/tls_v1.erl
@@ -34,7 +34,7 @@
 	 ecc_curves/1, ecc_curves/2, oid_to_enum/1, enum_to_oid/1, 
 	 default_signature_algs/1, signature_algs/2,
          default_signature_schemes/1, signature_schemes/2,
-         groups/1, groups/2, group_to_enum/1, enum_to_group/1]).
+         groups/1, groups/2, group_to_enum/1, enum_to_group/1, default_groups/1]).
 
 -export([derive_secret/4, hkdf_expand_label/5, hkdf_extract/3, hkdf_expand/4]).
 
@@ -561,6 +561,11 @@ groups(all) ->
      ffdhe4096,
      ffdhe6144,
      ffdhe8192];
+groups(default) ->
+    [secp256r1,
+     secp384r1,
+     secp521r1,
+     ffdhe2048];
 groups(Minor) ->
     TLSGroups = groups(all),
     groups(Minor, TLSGroups).
@@ -571,6 +576,10 @@ groups(_Minor, TLSGroups) ->
     CryptoGroups = crypto:ec_curves() ++ [ffdhe2048,ffdhe3072,ffdhe4096,ffdhe6144,ffdhe8192],
     lists:filter(fun(Group) -> proplists:get_bool(Group, CryptoGroups) end, TLSGroups).
 
+default_groups(Minor) ->
+    TLSGroups = groups(default),
+    groups(Minor, TLSGroups).
+
 group_to_enum(secp256r1) -> 23;
 group_to_enum(secp384r1) -> 24;
 group_to_enum(secp521r1) -> 25;