diff options
Diffstat (limited to 'lib/ssh/src/ssh_transport.erl')
-rw-r--r-- | lib/ssh/src/ssh_transport.erl | 247 |
1 files changed, 167 insertions, 80 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 2e7391e1f8..ce0762bf96 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 +66,8 @@ 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) -> + supported_algorithms(kex, ['diffie-hellman-group-exchange-sha1']); default_algorithms(Alg) -> supported_algorithms(Alg). @@ -73,7 +75,8 @@ default_algorithms(Alg) -> supported_algorithms() -> [{K,supported_algorithms(K)} || K <- algo_classes()]. supported_algorithms(kex) -> - ['diffie-hellman-group1-sha1']; + ['diffie-hellman-group1-sha1', + 'diffie-hellman-group-exchange-sha1']; supported_algorithms(public_key) -> ssh_auth:default_public_key_algorithms(); supported_algorithms(cipher) -> @@ -135,7 +138,7 @@ 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 +147,7 @@ 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), @@ -282,9 +285,14 @@ verify_algorithm(#alg{kex = 'diffie-hellman-group1-sha1'}) -> true; verify_algorithm(#alg{kex = 'diffie-hellman-group-exchange-sha1'}) -> 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}}}}; @@ -295,13 +303,18 @@ key_exchange_first_msg('diffie-hellman-group-exchange-sha1', Ssh0) -> 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) -> @@ -314,101 +327,176 @@ 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_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) -> - {Private, Public} = dh_gen_key(G,P,1024), - {SshPacket, Ssh1} = - ssh_packet(#ssh_msg_kex_dh_gex_init{e = Public}, Ssh0), - {ok, SshPacket, - Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}}}}. +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 = 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 -> + throw({Error, + #ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + description = "Key exchange failed", + language = "en"} + }) + end; -handle_new_keys(#ssh_msg_newkeys{}, Ssh0) -> - try install_alg(Ssh0) of - #ssh{} = Ssh -> - {ok, Ssh} - catch - error:_Error -> %% TODO: Throw earlier .... - throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, - description = "Install alg 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. -%% %% 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) -> +%%%---------------------------------------------------------------- +%%% +%%% diffie-hellman-group-exchange-sha1 +%%% +handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = Min, + n = NBits, + max = Max}, Ssh0) -> + %% server {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}}}}. + Ssh#ssh{keyex_key = {{Private, Public}, {G, P}}, + keyex_info = {Min, Max, NBits} + }}. + +handle_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) -> + %% client + {Private, Public} = dh_gen_key(G, P, 1024), + {SshPacket, Ssh1} = + 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 = ssh_math:ipow(E, Private, P), + 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) -> - 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) + Ssh0) -> + %% client + if + 1=<F, F=<(P-1)-> + K = ssh_math:ipow(F, Private, P), + 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 -> + {ok, Ssh} + catch + error:_Error -> %% TODO: Throw earlier .... + throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + description = "Install alg failed", + language = "en"}) + end. + %% select session id sid(#ssh{session_id = undefined}, H) -> H; @@ -511,7 +599,6 @@ 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 +1088,7 @@ 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]); |