Merge branch 'ingela/ssl/config-signature-algs/OTP-13463'

* ingela/ssl/config-signature-algs/OTP-13463:
  ssl: Remove default support for use of md5 in TLS 1.2 signature algorithms
  ssl: Add option signature_algs

1 files changed, 59 insertions, 1 deletions

diff --git a/lib/ssl/src/tls_v1.erl b/lib/ssl/src/tls_v1.erl
index 09e378cfeb..03cef633d5 100644
--- a/lib/ssl/src/tls_v1.erl
+++ b/lib/ssl/src/tls_v1.erl
@@ -31,7 +31,8 @@
 
 -export([master_secret/4, finished/5, certificate_verify/3, mac_hash/7,
 	 setup_keys/8, suites/1, prf/5,
-	 ecc_curves/1, oid_to_enum/1, enum_to_oid/1]).
+	 ecc_curves/1, oid_to_enum/1, enum_to_oid/1, 
+	 default_signature_algs/1, signature_algs/2]).
 
 %%====================================================================
 %% Internal application API
@@ -256,6 +257,52 @@ suites(3) ->
     ] ++ suites(2).
 
 
+
+signature_algs({3, 3}, HashSigns) ->
+    CryptoSupports =  crypto:supports(),
+    Hashes = proplists:get_value(hashs, CryptoSupports),
+    PubKeys = proplists:get_value(public_keys, CryptoSupports),
+    Supported = lists:foldl(fun({Hash, dsa = Sign} = Alg, Acc) ->
+				    case proplists:get_bool(dss, PubKeys) 
+					andalso proplists:get_bool(Hash, Hashes)
+					andalso is_pair(Hash, Sign, Hashes)
+				    of
+					true ->
+					    [Alg | Acc];
+					false ->
+					    Acc
+				    end;
+			       ({Hash, Sign} = Alg, Acc) -> 
+				    case proplists:get_bool(Sign, PubKeys) 
+					andalso proplists:get_bool(Hash, Hashes) 
+					andalso is_pair(Hash, Sign, Hashes)
+				    of
+					true ->
+					    [Alg | Acc];
+					false ->
+					    Acc
+				    end
+			    end, [], HashSigns),
+    lists:reverse(Supported).
+
+default_signature_algs({3, 3} = Version) ->
+    Default = [%% SHA2
+	       {sha512, ecdsa},
+	       {sha512, rsa},
+	       {sha384, ecdsa},
+	       {sha384, rsa},
+	       {sha256, ecdsa},
+	       {sha256, rsa},
+	       {sha224, ecdsa},
+	       {sha224, rsa},
+	       %% SHA
+	       {sha, ecdsa},
+	       {sha, rsa},
+	       {sha, dsa}],
+    signature_algs(Version, Default);
+default_signature_algs(_) ->
+    undefined.
+
 %%--------------------------------------------------------------------
 %%% Internal functions
 %%--------------------------------------------------------------------
@@ -340,6 +387,17 @@ finished_label(client) ->
 finished_label(server) ->
     <<"server finished">>.
 
+is_pair(sha, dsa, _) ->
+    true;
+is_pair(_, dsa, _) ->
+    false;
+is_pair(Hash, ecdsa, Hashs) ->
+    AtLeastSha = Hashs -- [md2,md4,md5],
+    lists:member(Hash, AtLeastSha);
+is_pair(Hash, rsa, Hashs) ->
+    AtLeastMd5 = Hashs -- [md2,md4],
+    lists:member(Hash, AtLeastMd5).
+
 %% list ECC curves in prefered order
 ecc_curves(_Minor) ->
     TLSCurves = [sect571r1,sect571k1,secp521r1,brainpoolP512r1,