Merge branch 'hans/ssh/x25519_x448/OTP-15133' into maint

* hans/ssh/x25519_x448/OTP-15133:
  ssh: Doc updates
  ssh: spec curve25519 & curve448
  ssh: Fix non-conforming key generation in kex for x25519 and x448
  ssh: Enable curve448-sha512 and curve25519-sha256
  ssh: Remove the term 'eddh'

3 files changed, 22 insertions, 15 deletions

diff --git a/lib/ssh/src/ssh.hrl b/lib/ssh/src/ssh.hrl
index 4ac5b7a2c1..66dbf0b144 100644
--- a/lib/ssh/src/ssh.hrl
+++ b/lib/ssh/src/ssh.hrl
@@ -118,6 +118,9 @@
                             'diffie-hellman-group14-sha256' |
                             'diffie-hellman-group16-sha512' |
                             'diffie-hellman-group18-sha512' |
+                            'curve25519-sha256' |
+                            '[email protected]' |
+                            'curve448-sha512' |
                             'ecdh-sha2-nistp256' |
                             'ecdh-sha2-nistp384' |
                             'ecdh-sha2-nistp521'
diff --git a/lib/ssh/src/ssh_message.erl b/lib/ssh/src/ssh_message.erl
index 55c0548c9b..da4027a763 100644
--- a/lib/ssh/src/ssh_message.erl
+++ b/lib/ssh/src/ssh_message.erl
@@ -289,12 +289,12 @@ encode(#ssh_msg_kex_dh_gex_reply{
     <<?Ebyte(?SSH_MSG_KEX_DH_GEX_REPLY), ?Ebinary(EncKey), ?Empint(F), ?Ebinary(EncSign)>>;
 
 encode(#ssh_msg_kex_ecdh_init{q_c = Q_c}) ->
-    <<?Ebyte(?SSH_MSG_KEX_ECDH_INIT), ?Empint(Q_c)>>;
+    <<?Ebyte(?SSH_MSG_KEX_ECDH_INIT), ?Ebinary(Q_c)>>;
 
 encode(#ssh_msg_kex_ecdh_reply{public_host_key = {Key,SigAlg}, q_s = Q_s, h_sig = Sign}) ->
     EncKey = public_key:ssh_encode(Key, ssh2_pubkey),
     EncSign = encode_signature(Key, SigAlg, Sign),
-    <<?Ebyte(?SSH_MSG_KEX_ECDH_REPLY), ?Ebinary(EncKey), ?Empint(Q_s), ?Ebinary(EncSign)>>;
+    <<?Ebyte(?SSH_MSG_KEX_ECDH_REPLY), ?Ebinary(EncKey), ?Ebinary(Q_s), ?Ebinary(EncSign)>>;
 
 encode(#ssh_msg_ignore{data = Data}) ->
     <<?Ebyte(?SSH_MSG_IGNORE), ?Estring_utf8(Data)>>;
@@ -504,13 +504,13 @@ decode(<<?BYTE(?SSH_MSG_KEX_DH_GEX_REPLY), ?DEC_BIN(Key,__0), ?DEC_MPINT(F,__1),
        h_sig = decode_signature(Hashsign)
       };
 
-decode(<<"ecdh",?BYTE(?SSH_MSG_KEX_ECDH_INIT), ?DEC_MPINT(Q_c,__0)>>) ->
+decode(<<"ecdh",?BYTE(?SSH_MSG_KEX_ECDH_INIT), ?DEC_BIN(Q_c,__0)>>) ->
     #ssh_msg_kex_ecdh_init{
        q_c = Q_c
       };
 
 decode(<<"ecdh",?BYTE(?SSH_MSG_KEX_ECDH_REPLY),
-	 ?DEC_BIN(Key,__1), ?DEC_MPINT(Q_s,__2), ?DEC_BIN(Sig,__3)>>) ->
+	 ?DEC_BIN(Key,__1), ?DEC_BIN(Q_s,__2), ?DEC_BIN(Sig,__3)>>) ->
     #ssh_msg_kex_ecdh_reply{
        public_host_key = public_key:ssh_decode(Key, ssh2_pubkey),
        q_s = Q_s,
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index d6b9142529..c5b0704925 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -104,10 +104,6 @@ algo_two_spec_class(_) -> false.
 
 default_algorithms(kex) ->
     supported_algorithms(kex, [
-                               %% Under devolpment:
-                               'curve25519-sha256',
-                               '[email protected]',
-                               'curve448-sha512',
                                %%  Gone in OpenSSH 7.3.p1:
                                'diffie-hellman-group1-sha1'
                               ]);
@@ -132,15 +128,15 @@ supported_algorithms(kex) ->
        {'ecdh-sha2-nistp384',                   [{public_keys,ecdh}, {curves,secp384r1}, {hashs,sha384}]},
        {'ecdh-sha2-nistp521',                   [{public_keys,ecdh}, {curves,secp521r1}, {hashs,sha512}]},
        {'ecdh-sha2-nistp256',                   [{public_keys,ecdh}, {curves,secp256r1}, {hashs,sha256}]},
-       %% https://tools.ietf.org/html/draft-ietf-curdle-ssh-curves
-       %% Secure Shell (SSH) Key Exchange Method using Curve25519 and Curve448
-       {'curve25519-sha256',                    [{public_keys,eddh}, {curves,x25519}, {hashs,sha256}]},
-       {'[email protected]',         [{public_keys,eddh}, {curves,x25519}, {hashs,sha256}]},
-       {'curve448-sha512',                      [{public_keys,eddh}, {curves,x448},   {hashs,sha512}]},
        {'diffie-hellman-group-exchange-sha256', [{public_keys,dh},   {hashs,sha256}]},
        {'diffie-hellman-group16-sha512',        [{public_keys,dh},   {hashs,sha512}]}, % In OpenSSH 7.3.p1
        {'diffie-hellman-group18-sha512',        [{public_keys,dh},   {hashs,sha512}]}, % In OpenSSH 7.3.p1
        {'diffie-hellman-group14-sha256',        [{public_keys,dh},   {hashs,sha256}]}, % In OpenSSH 7.3.p1
+       %% https://tools.ietf.org/html/draft-ietf-curdle-ssh-curves
+       %% Secure Shell (SSH) Key Exchange Method using Curve25519 and Curve448
+       {'curve25519-sha256',                    [{public_keys,ecdh}, {curves,x25519}, {hashs,sha256}]},
+       {'[email protected]',         [{public_keys,ecdh}, {curves,x25519}, {hashs,sha256}]},
+       {'curve448-sha512',                      [{public_keys,ecdh}, {curves,x448},   {hashs,sha512}]},
        {'diffie-hellman-group14-sha1',          [{public_keys,dh},   {hashs,sha}]},
        {'diffie-hellman-group-exchange-sha1',   [{public_keys,dh},   {hashs,sha}]},
        {'diffie-hellman-group1-sha1',           [{public_keys,dh},   {hashs,sha}]}
@@ -1897,6 +1893,7 @@ hash(K, H, Ki, N, HashAlg) ->
 kex_hash(SSH, Key, HashAlg, Args) ->
     crypto:hash(HashAlg, kex_plaintext(SSH,Key,Args)).
 
+
 kex_plaintext(SSH, Key, Args) ->
     EncodedKey = public_key:ssh_encode(Key, ssh2_pubkey),
     <<?Estring(SSH#ssh.c_version), ?Estring(SSH#ssh.s_version),
@@ -1904,8 +1901,13 @@ kex_plaintext(SSH, Key, Args) ->
       ?Ebinary(EncodedKey),
       (kex_alg_dependent(Args))/binary>>.
 
+
+kex_alg_dependent({Q_c, Q_s, K}) when is_binary(Q_c), is_binary(Q_s) ->
+    %% ecdh
+    <<?Ebinary(Q_c), ?Ebinary(Q_s), ?Empint(K)>>;
+
 kex_alg_dependent({E, F, K}) ->
-    %% diffie-hellman and ec diffie-hellman (with E = Q_c, F = Q_s)
+    %% diffie-hellman
     <<?Empint(E), ?Empint(F), ?Empint(K)>>;
 
 kex_alg_dependent({-1, NBits, -1, Prime, Gen, E, F, K}) ->
@@ -2024,11 +2026,13 @@ parallell_gen_key(Ssh = #ssh{keyex_key = {x, {G, P}},
     Ssh#ssh{keyex_key = {{Private, Public}, {G, P}}}.
 
 
+generate_key(ecdh = Algorithm, Args) ->
+    crypto:generate_key(Algorithm, Args);
 generate_key(Algorithm, Args) ->
     {Public,Private} = crypto:generate_key(Algorithm, Args),
     {crypto:bytes_to_integer(Public), crypto:bytes_to_integer(Private)}.
 
-      
+
 compute_key(Algorithm, OthersPublic, MyPrivate, Args) ->
     Shared = crypto:compute_key(Algorithm, OthersPublic, MyPrivate, Args),
     crypto:bytes_to_integer(Shared).