ssl: Implement DTLS state machine

Beta DTLS, not production ready. Only very basically tested, and
not everything in the SPEC is implemented and some things
are hard coded that should not be, so this implementation can not be consider
secure.

Refactor "TLS connection state" and socket handling, to facilitate
DTLS implementation.

Create dtls "listner" (multiplexor) process that spawns
DTLS connection process handlers.

Handle DTLS fragmentation.

Framework for handling retransmissions.

Replay Detection is not implemented yet.

Alerts currently always handled as in TLS.

1 files changed, 27 insertions, 2 deletions

diff --git a/lib/ssl/src/ssl_cipher.erl b/lib/ssl/src/ssl_cipher.erl
index 605bbd859a..32fec03b8e 100644
--- a/lib/ssl/src/ssl_cipher.erl
+++ b/lib/ssl/src/ssl_cipher.erl
@@ -40,7 +40,7 @@
 	 ec_keyed_suites/0, anonymous_suites/1, psk_suites/1, srp_suites/0,
 	 rc4_suites/1, des_suites/1, openssl_suite/1, openssl_suite_name/1, filter/2, filter_suites/1,
 	 hash_algorithm/1, sign_algorithm/1, is_acceptable_hash/2, is_fallback/1,
-	 random_bytes/1]).
+	 random_bytes/1, calc_aad/3, calc_mac_hash/4]).
 
 -export_type([cipher_suite/0,
 	      erl_cipher_suite/0, openssl_cipher_suite/0,
@@ -311,7 +311,9 @@ aead_decipher(Type, #cipher_state{key = Key, iv = IV} = CipherState,
 suites({3, 0}) ->
     ssl_v3:suites();
 suites({3, N}) ->
-    tls_v1:suites(N).
+    tls_v1:suites(N);
+suites(Version) ->
+    suites(dtls_v1:corresponding_tls_version(Version)).
 
 all_suites(Version) ->
     suites(Version)
@@ -1525,9 +1527,32 @@ is_fallback(CipherSuites)->
 random_bytes(N) ->
     crypto:strong_rand_bytes(N).
 
+calc_aad(Type, {MajVer, MinVer},
+	 #{sequence_number := SeqNo}) ->
+    <<SeqNo:64/integer, ?BYTE(Type), ?BYTE(MajVer), ?BYTE(MinVer)>>.
+
+calc_mac_hash(Type, Version,
+	      PlainFragment, #{sequence_number := SeqNo,
+			       mac_secret := MacSecret,
+			       security_parameters:=
+				   SecPars}) ->
+    Length = erlang:iolist_size(PlainFragment),
+    mac_hash(Version, SecPars#security_parameters.mac_algorithm,
+	     MacSecret, SeqNo, Type,
+	     Length, PlainFragment).
+
 %%--------------------------------------------------------------------
 %%% Internal functions
 %%--------------------------------------------------------------------
+mac_hash({_,_}, ?NULL, _MacSecret, _SeqNo, _Type,
+	 _Length, _Fragment) ->
+    <<>>;
+mac_hash({3, 0}, MacAlg, MacSecret, SeqNo, Type, Length, Fragment) ->
+    ssl_v3:mac_hash(MacAlg, MacSecret, SeqNo, Type, Length, Fragment);
+mac_hash({3, N} = Version, MacAlg, MacSecret, SeqNo, Type, Length, Fragment)  
+  when N =:= 1; N =:= 2; N =:= 3 ->
+    tls_v1:mac_hash(MacAlg, MacSecret, SeqNo, Type, Version,
+		      Length, Fragment).
 
 bulk_cipher_algorithm(null) ->
     ?NULL;