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-rw-r--r--lib/ssh/src/ssh_transport.erl341
1 files changed, 245 insertions, 96 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index 2e7391e1f8..9be8e45aed 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -39,7 +39,7 @@
key_exchange_init_msg/1,
key_init/3, new_keys_message/1,
handle_kexinit_msg/3, handle_kexdh_init/2,
- handle_kex_dh_gex_group/2, handle_kex_dh_gex_reply/2,
+ handle_kex_dh_gex_group/2, handle_kex_dh_gex_init/2, handle_kex_dh_gex_reply/2,
handle_new_keys/2, handle_kex_dh_gex_request/2,
handle_kexdh_reply/2,
unpack/3, decompress/2, ssh_packet/2, pack/2, msg_data/1,
@@ -66,6 +66,11 @@ algo_classes() -> [kex, public_key, cipher, mac, compression].
default_algorithms(compression) ->
%% Do not announce '[email protected]' because there seem to be problems
supported_algorithms(compression, same(['[email protected]']));
+default_algorithms(kex) ->
+ %% Do not announce the experimental 'diffie-hellman-group-exchange-sha*' yet
+ supported_algorithms(kex, ['diffie-hellman-group-exchange-sha1',
+ 'diffie-hellman-group-exchange-sha256'
+ ]);
default_algorithms(Alg) ->
supported_algorithms(Alg).
@@ -73,23 +78,28 @@ default_algorithms(Alg) ->
supported_algorithms() -> [{K,supported_algorithms(K)} || K <- algo_classes()].
supported_algorithms(kex) ->
- ['diffie-hellman-group1-sha1'];
+ select_crypto_supported(
+ [{'diffie-hellman-group1-sha1', [{hashs,sha}]},
+ {'diffie-hellman-group-exchange-sha1', [{hashs,sha}]},
+ {'diffie-hellman-group-exchange-sha256', [{hashs,sha256}]}
+ ]);
supported_algorithms(public_key) ->
ssh_auth:default_public_key_algorithms();
supported_algorithms(cipher) ->
- Supports = crypto:supports(),
- CipherAlgos = [{aes_ctr, 'aes128-ctr'}, {aes_cbc128, 'aes128-cbc'}, {des3_cbc, '3des-cbc'}],
- Algs = [SshAlgo ||
- {CryptoAlgo, SshAlgo} <- CipherAlgos,
- lists:member(CryptoAlgo, proplists:get_value(ciphers, Supports, []))],
- same(Algs);
+ same(
+ select_crypto_supported(
+ [{'aes128-ctr', [{ciphers,aes_ctr}]},
+ {'aes128-cbc', [{ciphers,aes_cbc128}]},
+ {'3des-cbc', [{ciphers,des3_cbc}]}
+ ]
+ ));
supported_algorithms(mac) ->
- Supports = crypto:supports(),
- HashAlgos = [{sha256, 'hmac-sha2-256'}, {sha, 'hmac-sha1'}],
- Algs = [SshAlgo ||
- {CryptoAlgo, SshAlgo} <- HashAlgos,
- lists:member(CryptoAlgo, proplists:get_value(hashs, Supports, []))],
- same(Algs);
+ same(
+ select_crypto_supported(
+ [{'hmac-sha2-256', [{hashs,sha256}]},
+ {'hmac-sha1', [{hashs,sha}]}
+ ]
+ ));
supported_algorithms(compression) ->
same(['none','zlib','[email protected]']).
@@ -100,7 +110,15 @@ supported_algorithms(Key, [{client2server,BL1},{server2client,BL2}]) ->
supported_algorithms(Key, BlackList) ->
supported_algorithms(Key) -- BlackList.
-
+select_crypto_supported(L) ->
+ Sup = crypto:supports(),
+ [Name || {Name,CryptoRequires} <- L,
+ crypto_supported(CryptoRequires, Sup)].
+
+crypto_supported(Conditions, Supported) ->
+ lists:all(fun({Tag,CryptoName}) ->
+ lists:member(CryptoName, proplists:get_value(Tag,Supported,[]))
+ end, Conditions).
same(Algs) -> [{client2server,Algs}, {server2client,Algs}].
@@ -135,7 +153,7 @@ ssh_vsn() ->
_:_ -> ""
end.
-random_id(Nlo, Nup) ->
+random_id(Nlo, Nup) ->
[crypto:rand_uniform($a,$z+1) || _<- lists:duplicate(crypto:rand_uniform(Nlo,Nup+1),x) ].
hello_version_msg(Data) ->
@@ -144,7 +162,7 @@ hello_version_msg(Data) ->
next_seqnum(SeqNum) ->
(SeqNum + 1) band 16#ffffffff.
-decrypt_first_block(Bin, #ssh{decrypt_block_size = BlockSize} = Ssh0) ->
+decrypt_first_block(Bin, #ssh{decrypt_block_size = BlockSize} = Ssh0) ->
<<EncBlock:BlockSize/binary, EncData/binary>> = Bin,
{Ssh, <<?UINT32(PacketLen), _/binary>> = DecData} =
decrypt(Ssh0, EncBlock),
@@ -280,33 +298,45 @@ verify_algorithm(#alg{decompress = undefined}) -> false;
verify_algorithm(#alg{kex = 'diffie-hellman-group1-sha1'}) -> true;
verify_algorithm(#alg{kex = 'diffie-hellman-group-exchange-sha1'}) -> true;
+verify_algorithm(#alg{kex = 'diffie-hellman-group-exchange-sha256'}) -> true;
verify_algorithm(_) -> false.
+%%%----------------------------------------------------------------
+%%%
+%%% Key exchange initialization
+%%%
key_exchange_first_msg('diffie-hellman-group1-sha1', Ssh0) ->
{G, P} = dh_group1(),
{Private, Public} = dh_gen_key(G, P, 1024),
+ %% Public = G^Private mod P (def)
{SshPacket, Ssh1} = ssh_packet(#ssh_msg_kexdh_init{e = Public}, Ssh0),
{ok, SshPacket,
Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}}}};
-key_exchange_first_msg('diffie-hellman-group-exchange-sha1', Ssh0) ->
+key_exchange_first_msg(Kex, Ssh0) when Kex == 'diffie-hellman-group-exchange-sha1' ;
+ Kex == 'diffie-hellman-group-exchange-sha256' ->
Min = ?DEFAULT_DH_GROUP_MIN,
NBits = ?DEFAULT_DH_GROUP_NBITS,
Max = ?DEFAULT_DH_GROUP_MAX,
{SshPacket, Ssh1} =
ssh_packet(#ssh_msg_kex_dh_gex_request{min = Min,
- n = NBits, max = Max},
+ n = NBits,
+ max = Max},
Ssh0),
{ok, SshPacket,
Ssh1#ssh{keyex_info = {Min, Max, NBits}}}.
-
+%%%----------------------------------------------------------------
+%%%
+%%% diffie-hellman-group1-sha1
+%%%
handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Ssh0) ->
+ %% server
{G, P} = dh_group1(),
if
1=<E, E=<(P-1) ->
{Private, Public} = dh_gen_key(G, P, 1024),
- K = ssh_math:ipow(E, Private, P),
+ K = dh_compute_key(G, P, E, Private),
Key = get_host_key(Ssh0),
H = kex_h(Ssh0, Key, E, Public, K),
H_SIG = sign_host_key(Ssh0, Key, H),
@@ -314,27 +344,172 @@ handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Ssh0) ->
f = Public,
h_sig = H_SIG
}, Ssh0),
-
{ok, SshPacket, Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}},
shared_secret = K,
exchanged_hash = H,
session_id = sid(Ssh1, H)}};
+
true ->
- Error = {error,bad_e_from_peer},
- Disconnect = #ssh_msg_disconnect{
- code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
- description = "Key exchange failed, 'f' out of bounds",
- language = "en"},
- throw({Error, Disconnect})
+ throw({{error,bad_e_from_peer},
+ #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, 'e' out of bounds",
+ language = ""}
+ })
end.
+handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey,
+ f = F,
+ h_sig = H_SIG},
+ #ssh{keyex_key = {{Private, Public}, {G, P}}} = Ssh0) ->
+ %% client
+ if
+ 1=<F, F=<(P-1)->
+ K = dh_compute_key(G, P, F, Private),
+ H = kex_h(Ssh0, HostKey, Public, F, K),
+
+ case verify_host_key(Ssh0, HostKey, H, H_SIG) of
+ ok ->
+ {SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
+ {ok, SshPacket, Ssh#ssh{shared_secret = K,
+ exchanged_hash = H,
+ session_id = sid(Ssh, H)}};
+ Error ->
+ throw({Error,
+ #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed",
+ language = "en"}
+ })
+ end;
+
+ true ->
+ throw({{error,bad_f_from_peer},
+ #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, 'f' out of bounds",
+ language = ""}
+ })
+ end.
+
+
+%%%----------------------------------------------------------------
+%%%
+%%% diffie-hellman-group-exchange-sha1
+%%%
+handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = Min,
+ n = NBits,
+ max = Max}, Ssh0) when Min=<NBits, NBits=<Max ->
+ %% server
+ {G, P} = dh_gex_group(Min, NBits, Max),
+ {Private, Public} = dh_gen_key(G, P, 1024),
+ {SshPacket, Ssh} =
+ ssh_packet(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0),
+ {ok, SshPacket,
+ Ssh#ssh{keyex_key = {{Private, Public}, {G, P}},
+ keyex_info = {Min, Max, NBits}
+ }};
+handle_kex_dh_gex_request(_, _) ->
+ throw({{error,bad_ssh_msg_kex_dh_gex_request},
+ #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, bad values in ssh_msg_kex_dh_gex_request",
+ language = ""}
+ }).
+
handle_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) ->
- {Private, Public} = dh_gen_key(G,P,1024),
+ %% client
+ {Private, Public} = dh_gen_key(G, P, 1024),
{SshPacket, Ssh1} =
- ssh_packet(#ssh_msg_kex_dh_gex_init{e = Public}, Ssh0),
+ ssh_packet(#ssh_msg_kex_dh_gex_init{e = Public}, Ssh0), % Pub = G^Priv mod P (def)
+
{ok, SshPacket,
Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}}}}.
+handle_kex_dh_gex_init(#ssh_msg_kex_dh_gex_init{e = E},
+ #ssh{keyex_key = {{Private, Public}, {G, P}},
+ keyex_info = {Min, Max, NBits}} =
+ Ssh0) ->
+ %% server
+ if
+ 1=<E, E=<(P-1) ->
+ K = dh_compute_key(G, P, E, Private),
+ if
+ 1<K, K<(P-1) ->
+ HostKey = get_host_key(Ssh0),
+ H = kex_h(Ssh0, HostKey, Min, NBits, Max, P, G, E, Public, K),
+ H_SIG = sign_host_key(Ssh0, HostKey, H),
+ {SshPacket, Ssh} =
+ ssh_packet(#ssh_msg_kex_dh_gex_reply{public_host_key = HostKey,
+ f = Public,
+ h_sig = H_SIG}, Ssh0),
+ {ok, SshPacket, Ssh#ssh{shared_secret = K,
+ exchanged_hash = H,
+ session_id = sid(Ssh, H)
+ }};
+ true ->
+ throw({{error,bad_K},
+ #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, 'K' out of bounds",
+ language = ""}
+ })
+ end;
+ true ->
+ throw({{error,bad_e_from_peer},
+ #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, 'e' out of bounds",
+ language = ""}
+ })
+ end.
+
+handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = HostKey,
+ f = F,
+ h_sig = H_SIG},
+ #ssh{keyex_key = {{Private, Public}, {G, P}},
+ keyex_info = {Min, Max, NBits}} =
+ Ssh0) ->
+ %% client
+ if
+ 1=<F, F=<(P-1)->
+ K = dh_compute_key(G, P, F, Private),
+ if
+ 1<K, K<(P-1) ->
+ H = kex_h(Ssh0, HostKey, Min, NBits, Max, P, G, Public, F, K),
+
+ case verify_host_key(Ssh0, HostKey, H, H_SIG) of
+ ok ->
+ {SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
+ {ok, SshPacket, Ssh#ssh{shared_secret = K,
+ exchanged_hash = H,
+ session_id = sid(Ssh, H)}};
+ _Error ->
+ throw(#ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed",
+ language = ""}
+ )
+ end;
+
+ true ->
+ throw({{error,bad_K},
+ #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, 'K' out of bounds",
+ language = ""}
+ })
+ end;
+ true ->
+ throw({{error,bad_f_from_peer},
+ #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, 'f' out of bounds",
+ language = ""}
+ })
+ end.
+
+%%%----------------------------------------------------------------
handle_new_keys(#ssh_msg_newkeys{}, Ssh0) ->
try install_alg(Ssh0) of
#ssh{} = Ssh ->
@@ -346,69 +521,6 @@ handle_new_keys(#ssh_msg_newkeys{}, Ssh0) ->
language = "en"})
end.
-
-%% %% Select algorithms
-handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey, f = F,
- h_sig = H_SIG},
- #ssh{keyex_key = {{Private, Public}, {_G, P}}} = Ssh0) when 1=<F, F=<(P-1)->
- K = ssh_math:ipow(F, Private, P),
- H = kex_h(Ssh0, HostKey, Public, F, K),
-
- case verify_host_key(Ssh0, HostKey, H, H_SIG) of
- ok ->
- {SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
- {ok, SshPacket, Ssh#ssh{shared_secret = K,
- exchanged_hash = H,
- session_id = sid(Ssh, H)}};
- Error ->
- Disconnect = #ssh_msg_disconnect{
- code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
- description = "Key exchange failed",
- language = "en"},
- throw({Error, Disconnect})
- end;
-handle_kexdh_reply(#ssh_msg_kexdh_reply{}, _SSH) ->
- Error = {error,bad_f_from_peer},
- Disconnect = #ssh_msg_disconnect{
- code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
- description = "Key exchange failed, 'f' out of bounds",
- language = "en"},
- throw({Error, Disconnect}).
-
-
-handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = _Min,
- n = _NBits,
- max = _Max}, Ssh0) ->
- {G,P} = dh_group1(), %% TODO real imp this seems to be a hack?!
- {Private, Public} = dh_gen_key(G, P, 1024),
- {SshPacket, Ssh} =
- ssh_packet(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0),
- {ok, SshPacket,
- Ssh#ssh{keyex_key = {{Private, Public}, {G, P}}}}.
-
-handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = HostKey,
- f = F,
- h_sig = H_SIG},
- #ssh{keyex_key = {{Private, Public}, {G, P}},
- keyex_info = {Min, Max, NBits}} =
- Ssh0) ->
- K = ssh_math:ipow(F, Private, P),
- H = kex_h(Ssh0, HostKey, Min, NBits, Max, P, G, Public, F, K),
-
- case verify_host_key(Ssh0, HostKey, H, H_SIG) of
- ok ->
- {SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
- {ok, SshPacket, Ssh#ssh{shared_secret = K,
- exchanged_hash = H,
- session_id = sid(Ssh, H)}};
- _Error ->
- Disconnect = #ssh_msg_disconnect{
- code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
- description = "Key exchange failed",
- language = "en"},
- throw(Disconnect)
- end.
-
%% select session id
sid(#ssh{session_id = undefined}, H) ->
H;
@@ -511,7 +623,6 @@ select_algorithm(Role, Client, Server) ->
decompress = Decompression,
c_lng = C_Lng,
s_lng = S_Lng},
-%%ct:pal("~p~n Client=~p~n Server=~p~n Alg=~p~n",[Role,Client,Server,Alg]),
{ok, Alg}.
select_encrypt_decrypt(client, Client, Server) ->
@@ -1001,7 +1112,7 @@ recv_mac_init(SSH) ->
recv_mac_final(SSH) ->
{ok, SSH#ssh { recv_mac = none, recv_mac_key = undefined }}.
-mac(none, _ , _, _) ->
+mac(none, _ , _, _) ->
<<>>;
mac('hmac-sha1', Key, SeqNum, Data) ->
crypto:hmac(sha, Key, [<<?UINT32(SeqNum)>>, Data]);
@@ -1022,6 +1133,8 @@ hash(SSH, Char, Bits) ->
fun(Data) -> crypto:hash(sha, Data) end;
'diffie-hellman-group-exchange-sha1' ->
fun(Data) -> crypto:hash(sha, Data) end;
+ 'diffie-hellman-group-exchange-sha256' ->
+ fun(Data) -> crypto:hash(sha256, Data) end;
_ ->
exit({bad_algorithm,SSH#ssh.kex})
end,
@@ -1071,8 +1184,11 @@ kex_h(SSH, Key, Min, NBits, Max, Prime, Gen, E, F, K) ->
ssh_message:encode_host_key(Key), Min, NBits, Max,
Prime, Gen, E,F,K], Ts)
end,
- crypto:hash(sha,L).
+ crypto:hash(sha((SSH#ssh.algorithms)#alg.kex), L).
+sha('diffie-hellman-group-exchange-sha1') -> sha;
+sha('diffie-hellman-group-exchange-sha256') -> sha256.
+
mac_key_size('hmac-sha1') -> 20*8;
mac_key_size('hmac-sha1-96') -> 20*8;
mac_key_size('hmac-md5') -> 16*8;
@@ -1096,13 +1212,46 @@ peer_name({Host, _}) ->
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%% rfc 2489, ch 6.2
dh_group1() ->
{2, 16#FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF}.
+%%% rfc 3526, ch3
+dh_group14() ->
+ {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}.
+
+%%% rfc 3526, ch4
+dh_group15() ->
+ {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}.
+
+%%% rfc 3526, ch5
+dh_group16() ->
+ {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}.
+
+
+%%% First try exact match:
+dh_gex_group(_Min, N, _Max) when N==1024 -> dh_group1();
+dh_gex_group(_Min, N, _Max) when N==2048 -> dh_group14();
+dh_gex_group(_Min, N, _Max) when N==3072 -> dh_group15();
+dh_gex_group(_Min, N, _Max) when N==4096 -> dh_group16();
+%%% If not an exact match, select the largest possible:
+dh_gex_group(Min, _N, Max) when Min=<4096, 4096=<Max -> dh_group16();
+dh_gex_group(Min, _N, Max) when Min=<3072, 3072=<Max -> dh_group15();
+dh_gex_group(Min, _N, Max) when Min=<2048, 2048=<Max -> dh_group14();
+dh_gex_group(Min, _N, Max) when Min=<1024, 1024=<Max -> dh_group1().
+
+
dh_gen_key(G, P, _) ->
{Public, Private} = crypto:generate_key(dh, [P, G]),
{crypto:bytes_to_integer(Private), crypto:bytes_to_integer(Public)}.
+dh_compute_key(G, P, OthersPublic, MyPrivate) ->
+ crypto:bytes_to_integer(
+ crypto:compute_key(dh, OthersPublic, MyPrivate, [P,G])
+ ).
+
+
+
trim_tail(Str) ->
lists:reverse(trim_head(lists:reverse(Str))).