Merge branch 'arekinath/ssh/aes-ctr' into maint

* arekinath/ssh/aes-ctr:
  ssh: check if ssh client supports newer cipher- and MAC-algorithms
  SSH: only enable ciphers/MACs when they are available in crypto
  SSH: add ssh_to_openssh test for ciphers and macs
  SSH: documentation update for new algos
  SSH: add support for aes128-ctr and hmac-sha2-256

3 files changed, 202 insertions, 16 deletions

diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml
index 876eba598a..9f5d1c003d 100644
--- a/lib/ssh/doc/src/ssh.xml
+++ b/lib/ssh/doc/src/ssh.xml
@@ -36,8 +36,8 @@
     <list type="bulleted">
       <item>SSH requires the crypto and public_key applications.</item>
       <item>Supported SSH version is 2.0 </item>
-      <item>Supported MAC algorithms: hmac-sha1</item>
-      <item>Supported encryption algorithms: aes128-cb and 3des-cbc</item>
+      <item>Supported MAC algorithms: hmac-sha2-256 and hmac-sha1</item>
+      <item>Supported encryption algorithms: aes128-ctr, aes128-cb and 3des-cbc</item>
       <item>Supports unicode filenames if the emulator and the underlaying OS supports it. See the DESCRIPTION section in <seealso marker="kernel:file">file</seealso> for information about this subject</item>
       <item>Supports unicode in shell and cli</item>
     </list>
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index 27723dc870..ea05c849b7 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -113,15 +113,28 @@ key_init(client, Ssh, Value) ->
 key_init(server, Ssh, Value) ->
     Ssh#ssh{s_keyinit = Value}.
 
+available_ssh_algos() ->
+    Supports = crypto:supports(),
+    CipherAlgos = [{aes_ctr, "aes128-ctr"}, {aes_cbc128, "aes128-cbc"}, {des3_cbc, "3des-cbc"}],
+    Ciphers = [SshAlgo ||
+	{CryptoAlgo, SshAlgo} <- CipherAlgos,
+	lists:member(CryptoAlgo, proplists:get_value(ciphers, Supports, []))],
+    HashAlgos = [{sha256, "hmac-sha2-256"}, {sha, "hmac-sha1"}],
+    Hashs = [SshAlgo ||
+	{CryptoAlgo, SshAlgo} <- HashAlgos,
+	lists:member(CryptoAlgo, proplists:get_value(hashs, Supports, []))],
+    {Ciphers, Hashs}.
+
 kexinit_messsage(client, Random, Compression, HostKeyAlgs) ->
+    {CipherAlgs, HashAlgs} = available_ssh_algos(),
     #ssh_msg_kexinit{ 
 		  cookie = Random,
 		  kex_algorithms = ["diffie-hellman-group1-sha1"],
 		  server_host_key_algorithms = HostKeyAlgs,
-		  encryption_algorithms_client_to_server = ["aes128-cbc","3des-cbc"],
-		  encryption_algorithms_server_to_client = ["aes128-cbc","3des-cbc"],
-		  mac_algorithms_client_to_server = ["hmac-sha1"],
-		  mac_algorithms_server_to_client = ["hmac-sha1"],
+		  encryption_algorithms_client_to_server = CipherAlgs,
+		  encryption_algorithms_server_to_client = CipherAlgs,
+		  mac_algorithms_client_to_server = HashAlgs,
+		  mac_algorithms_server_to_client = HashAlgs,
 		  compression_algorithms_client_to_server = Compression,
 		  compression_algorithms_server_to_client = Compression,
 		  languages_client_to_server = [],
@@ -129,14 +142,15 @@ kexinit_messsage(client, Random, Compression, HostKeyAlgs) ->
 		 };
 
 kexinit_messsage(server, Random, Compression, HostKeyAlgs) ->
+    {CipherAlgs, HashAlgs} = available_ssh_algos(),
     #ssh_msg_kexinit{
 		  cookie = Random,
 		  kex_algorithms = ["diffie-hellman-group1-sha1"],
 		  server_host_key_algorithms = HostKeyAlgs,
-		  encryption_algorithms_client_to_server = ["aes128-cbc","3des-cbc"],
-		  encryption_algorithms_server_to_client = ["aes128-cbc","3des-cbc"],
-		  mac_algorithms_client_to_server = ["hmac-sha1"],
-		  mac_algorithms_server_to_client = ["hmac-sha1"],
+		  encryption_algorithms_client_to_server = CipherAlgs,
+		  encryption_algorithms_server_to_client = CipherAlgs,
+		  mac_algorithms_client_to_server = HashAlgs,
+		  mac_algorithms_server_to_client = HashAlgs,
 		  compression_algorithms_client_to_server = Compression,
 		  compression_algorithms_server_to_client = Compression,
 		  languages_client_to_server = [],
@@ -636,7 +650,21 @@ encrypt_init(#ssh{encrypt = 'aes128-cbc', role = server} = Ssh) ->
     <<K:16/binary>> = hash(Ssh, "D", 128),
     {ok, Ssh#ssh{encrypt_keys = K,
 		 encrypt_block_size = 16,
-                 encrypt_ctx = IV}}.
+                 encrypt_ctx = IV}};
+encrypt_init(#ssh{encrypt = 'aes128-ctr', role = client} = Ssh) ->
+	IV = hash(Ssh, "A", 128),
+    <<K:16/binary>> = hash(Ssh, "C", 128),
+    State = crypto:stream_init(aes_ctr, K, IV),
+    {ok, Ssh#ssh{encrypt_keys = K,
+		 encrypt_block_size = 16,
+                 encrypt_ctx = State}};
+encrypt_init(#ssh{encrypt = 'aes128-ctr', role = server} = Ssh) ->
+	IV = hash(Ssh, "B", 128),
+    <<K:16/binary>> = hash(Ssh, "D", 128),
+    State = crypto:stream_init(aes_ctr, K, IV),
+    {ok, Ssh#ssh{encrypt_keys = K,
+		 encrypt_block_size = 16,
+                 encrypt_ctx = State}}.
 
 encrypt_final(Ssh) ->
     {ok, Ssh#ssh{encrypt = none, 
@@ -658,7 +686,11 @@ encrypt(#ssh{encrypt = 'aes128-cbc',
             encrypt_ctx = IV0} = Ssh, Data) ->
     Enc = crypto:block_encrypt(aes_cbc128, K,IV0,Data),
     IV = crypto:next_iv(aes_cbc, Enc),
-    {Ssh#ssh{encrypt_ctx = IV}, Enc}.
+    {Ssh#ssh{encrypt_ctx = IV}, Enc};
+encrypt(#ssh{encrypt = 'aes128-ctr',
+            encrypt_ctx = State0} = Ssh, Data) ->
+    {State, Enc} = crypto:stream_encrypt(State0,Data),
+    {Ssh#ssh{encrypt_ctx = State}, Enc}.
   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -690,7 +722,21 @@ decrypt_init(#ssh{decrypt = 'aes128-cbc', role = server} = Ssh) ->
 		hash(Ssh, "C", 128)},
     <<K:16/binary>> = KD,
     {ok, Ssh#ssh{decrypt_keys = K, decrypt_ctx = IV,
-		 decrypt_block_size = 16}}.
+		 decrypt_block_size = 16}};
+decrypt_init(#ssh{decrypt = 'aes128-ctr', role = client} = Ssh) ->
+	IV = hash(Ssh, "B", 128),
+    <<K:16/binary>> = hash(Ssh, "D", 128),
+    State = crypto:stream_init(aes_ctr, K, IV),
+    {ok, Ssh#ssh{decrypt_keys = K,
+		 decrypt_block_size = 16,
+                 decrypt_ctx = State}};
+decrypt_init(#ssh{decrypt = 'aes128-ctr', role = server} = Ssh) ->
+	IV = hash(Ssh, "A", 128),
+    <<K:16/binary>> = hash(Ssh, "C", 128),
+    State = crypto:stream_init(aes_ctr, K, IV),
+    {ok, Ssh#ssh{decrypt_keys = K,
+		 decrypt_block_size = 16,
+                 decrypt_ctx = State}}.
 
   
 decrypt_final(Ssh) ->
@@ -711,7 +757,11 @@ decrypt(#ssh{decrypt = 'aes128-cbc', decrypt_keys = Key,
 	     decrypt_ctx = IV0} = Ssh, Data) ->
     Dec = crypto:block_decrypt(aes_cbc128, Key,IV0,Data),
     IV = crypto:next_iv(aes_cbc, Data),
-    {Ssh#ssh{decrypt_ctx = IV}, Dec}.
+    {Ssh#ssh{decrypt_ctx = IV}, Dec};
+decrypt(#ssh{decrypt = 'aes128-ctr',
+            decrypt_ctx = State0} = Ssh, Data) ->
+    {State, Enc} = crypto:stream_decrypt(State0,Data),
+    {Ssh#ssh{decrypt_ctx = State}, Enc}.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Compression
@@ -846,7 +896,9 @@ mac('hmac-sha1-96', Key, SeqNum, Data) ->
 mac('hmac-md5', Key, SeqNum, Data) ->
     crypto:hmac(md5, Key, [<<?UINT32(SeqNum)>>, Data]);
 mac('hmac-md5-96', Key, SeqNum, Data) ->
-    crypto:hmac(md5, Key, [<<?UINT32(SeqNum)>>, Data], mac_digest_size('hmac-md5-96')).
+    crypto:hmac(md5, Key, [<<?UINT32(SeqNum)>>, Data], mac_digest_size('hmac-md5-96'));
+mac('hmac-sha2-256', Key, SeqNum, Data) ->
+	crypto:hmac(sha256, Key, [<<?UINT32(SeqNum)>>, Data]).
 
 %% return N hash bytes (HASH)
 hash(SSH, Char, Bits) ->
@@ -911,12 +963,14 @@ mac_key_size('hmac-sha1')    -> 20*8;
 mac_key_size('hmac-sha1-96') -> 20*8;
 mac_key_size('hmac-md5')     -> 16*8;
 mac_key_size('hmac-md5-96')  -> 16*8;
+mac_key_size('hmac-sha2-256')-> 32*8;
 mac_key_size(none) -> 0.
 
 mac_digest_size('hmac-sha1')    -> 20;
 mac_digest_size('hmac-sha1-96') -> 12;
 mac_digest_size('hmac-md5')    -> 20;
 mac_digest_size('hmac-md5-96') -> 12;
+mac_digest_size('hmac-sha2-256') -> 32;
 mac_digest_size(none) -> 0.
 
 peer_name({Host, _}) ->
diff --git a/lib/ssh/test/ssh_to_openssh_SUITE.erl b/lib/ssh/test/ssh_to_openssh_SUITE.erl
index 8b5343cecc..3500bf012b 100644
--- a/lib/ssh/test/ssh_to_openssh_SUITE.erl
+++ b/lib/ssh/test/ssh_to_openssh_SUITE.erl
@@ -54,7 +54,9 @@ groups() ->
 			 ]},
      {erlang_server, [], [erlang_server_openssh_client_exec,
 			  erlang_server_openssh_client_exec_compressed,
-			  erlang_server_openssh_client_pulic_key_dsa]}
+			  erlang_server_openssh_client_pulic_key_dsa,
+			  erlang_server_openssh_client_cipher_suites,
+			  erlang_server_openssh_client_macs]}
     ].
 
 init_per_suite(Config) ->
@@ -89,6 +91,12 @@ end_per_group(erlang_server, Config) ->
 end_per_group(_, Config) ->
     Config.
 
+init_per_testcase(erlang_server_openssh_client_cipher_suites, Config) ->
+    check_ssh_client_support(Config);
+
+init_per_testcase(erlang_server_openssh_client_macs, Config) ->
+    check_ssh_client_support(Config);
+
 init_per_testcase(_TestCase, Config) ->
     ssh:start(),
     Config.
@@ -221,6 +229,108 @@ erlang_server_openssh_client_exec(Config) when is_list(Config) ->
      ssh:stop_daemon(Pid).
 
 %%--------------------------------------------------------------------
+erlang_server_openssh_client_cipher_suites() ->
+    [{doc, "Test that we can connect with different cipher suites."}].
+
+erlang_server_openssh_client_cipher_suites(Config) when is_list(Config) ->
+    SystemDir = ?config(data_dir, Config),
+    PrivDir = ?config(priv_dir, Config),
+    KnownHosts = filename:join(PrivDir, "known_hosts"),
+
+    {Pid, Host, Port} = ssh_test_lib:daemon([{system_dir, SystemDir},
+					     {failfun, fun ssh_test_lib:failfun/2}]),
+
+
+    ct:sleep(500),
+
+    Supports = crypto:supports(),
+    Ciphers = proplists:get_value(ciphers, Supports),
+    Tests = [
+        {"3des-cbc", lists:member(des3_cbc, Ciphers)},
+        {"aes128-cbc", lists:member(aes_cbc128, Ciphers)},
+        {"aes128-ctr", lists:member(aes_ctr, Ciphers)},
+        {"aes256-cbc", false}
+    ],
+    lists:foreach(fun({Cipher, Expect}) ->
+        Cmd = "ssh -p " ++ integer_to_list(Port) ++
+        " -o UserKnownHostsFile=" ++ KnownHosts ++ " " ++ Host ++ " " ++
+        " -c " ++ Cipher ++ " 1+1.",
+
+        ct:pal("Cmd: ~p~n", [Cmd]),
+
+        SshPort = open_port({spawn, Cmd}, [binary, stderr_to_stdout]),
+
+        case Expect of
+            true ->
+                receive
+                    {SshPort,{data, <<"2\n">>}} ->
+                       ok
+                after ?TIMEOUT ->
+                    ct:fail("Did not receive answer")
+                end;
+            false ->
+                receive
+                    {SshPort,{data, <<"no matching cipher found", _/binary>>}} ->
+                        ok
+                after ?TIMEOUT ->
+                    ct:fail("Did not receive no matching cipher message")
+                end
+        end
+    end, Tests),
+
+     ssh:stop_daemon(Pid).
+
+%%--------------------------------------------------------------------
+erlang_server_openssh_client_macs() ->
+    [{doc, "Test that we can connect with different MACs."}].
+
+erlang_server_openssh_client_macs(Config) when is_list(Config) ->
+    SystemDir = ?config(data_dir, Config),
+    PrivDir = ?config(priv_dir, Config),
+    KnownHosts = filename:join(PrivDir, "known_hosts"),
+
+    {Pid, Host, Port} = ssh_test_lib:daemon([{system_dir, SystemDir},
+                         {failfun, fun ssh_test_lib:failfun/2}]),
+
+
+    ct:sleep(500),
+
+    Supports = crypto:supports(),
+    Hashs = proplists:get_value(hashs, Supports),
+    MACs = [{"hmac-sha1", lists:member(sha, Hashs)},
+        {"hmac-sha2-256", lists:member(sha256, Hashs)},
+        {"hmac-md5-96", false},
+        {"hmac-ripemd160", false}],
+    lists:foreach(fun({MAC, Expect}) ->
+        Cmd = "ssh -p " ++ integer_to_list(Port) ++
+        " -o UserKnownHostsFile=" ++ KnownHosts ++ " " ++ Host ++ " " ++
+        " -o MACs=" ++ MAC ++ " 1+1.",
+
+        ct:pal("Cmd: ~p~n", [Cmd]),
+
+        SshPort = open_port({spawn, Cmd}, [binary, stderr_to_stdout]),
+
+        case Expect of
+            true ->
+                receive
+                    {SshPort,{data, <<"2\n">>}} ->
+                       ok
+                after ?TIMEOUT ->
+                    ct:fail("Did not receive answer")
+                end;
+            false ->
+                receive
+                    {SshPort,{data, <<"no matching mac found", _/binary>>}} ->
+                        ok
+                after ?TIMEOUT ->
+                    ct:fail("Did not receive no matching mac message")
+                end
+        end
+    end, MACs),
+
+     ssh:stop_daemon(Pid).
+
+%%--------------------------------------------------------------------
 erlang_server_openssh_client_exec_compressed() ->
     [{doc, "Test that exec command works."}].
 
@@ -433,3 +543,25 @@ receive_hej() ->
 	    ct:pal("Extra info: ~p~n", [Info]),
 	    receive_hej()
     end.
+
+%%--------------------------------------------------------------------
+%%--------------------------------------------------------------------
+%% Check if we have a "newer" ssh client that supports these test cases
+%%--------------------------------------------------------------------
+check_ssh_client_support(Config) ->
+    Port = open_port({spawn, "ssh -Q cipher"}, [exit_status, stderr_to_stdout]),
+    case check_ssh_client_support2(Port) of
+	0 -> % exit status from command (0 == ok)
+	    ssh:start(),
+	    Config;
+	_ ->
+	    {skip, "test case not supported by ssh client"}
+    end.
+
+check_ssh_client_support2(P) ->
+    receive
+	{P, {data, _A}} ->
+	    check_ssh_client_support2(P);
+	{P, {exit_status, E}} ->
+	    E
+    end.