diff options
Diffstat (limited to 'lib/ssh/src/ssh_transport.erl')
| -rw-r--r-- | lib/ssh/src/ssh_transport.erl | 1440 |
1 files changed, 1128 insertions, 312 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 27723dc870..18037b8461 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -1,18 +1,19 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2004-2013. All Rights Reserved. +%% Copyright Ericsson AB 2004-2014. All Rights Reserved. %% -%% The contents of this file are subject to the Erlang Public License, -%% Version 1.1, (the "License"); you may not use this file except in -%% compliance with the License. You should have received a copy of the -%% Erlang Public License along with this software. If not, it can be -%% retrieved online at http://www.erlang.org/. +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at %% -%% Software distributed under the License is distributed on an "AS IS" -%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See -%% the License for the specific language governing rights and limitations -%% under the License. +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. %% %% %CopyrightEnd% %% @@ -30,26 +31,139 @@ -include("ssh.hrl"). -export([versions/2, hello_version_msg/1]). --export([next_seqnum/1, decrypt_first_block/2, decrypt_blocks/3, - is_valid_mac/3, +-export([next_seqnum/1, + supported_algorithms/0, supported_algorithms/1, + default_algorithms/0, default_algorithms/1, + handle_packet_part/4, handle_hello_version/1, 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, + handle_kex_ecdh_init/2, + handle_kex_ecdh_reply/2, + extract_public_key/1, + ssh_packet/2, pack/2, sign/3, verify/4]). +%%% For test suites +-export([pack/3]). +-export([decompress/2, decrypt_blocks/3, is_valid_mac/3 ]). % FIXME: remove + +%%%---------------------------------------------------------------------------- +%%% +%%% There is a difference between supported and default algorithms. The +%%% SUPPORTED algorithms can be handled (maybe untested...). The DEFAULT ones +%%% are announced in ssh_msg_kexinit and in ssh:default_algorithms/0 to the +%%% user. +%%% +%%% A supported algorithm can be requested in the option 'preferred_algorithms', +%%% but may give unexpected results before being promoted to default. +%%% +%%% This makes it possible to add experimental algorithms (in supported_algorithms) +%%% and test them without letting the default users know about them. +%%% + +default_algorithms() -> [{K,default_algorithms(K)} || K <- algo_classes()]. + +algo_classes() -> [kex, public_key, cipher, mac, compression]. + + +default_algorithms(cipher) -> + supported_algorithms(cipher, same(['AEAD_AES_128_GCM', + 'AEAD_AES_256_GCM'])); +default_algorithms(mac) -> + supported_algorithms(mac, same(['AEAD_AES_128_GCM', + 'AEAD_AES_256_GCM'])); +default_algorithms(Alg) -> + supported_algorithms(Alg, []). + + +supported_algorithms() -> [{K,supported_algorithms(K)} || K <- algo_classes()]. + +supported_algorithms(kex) -> + select_crypto_supported( + [ + {'ecdh-sha2-nistp256', [{public_keys,ecdh}, {ec_curve,secp256r1}, {hashs,sha256}]}, + {'ecdh-sha2-nistp384', [{public_keys,ecdh}, {ec_curve,secp384r1}, {hashs,sha384}]}, + {'diffie-hellman-group14-sha1', [{public_keys,dh}, {hashs,sha}]}, + {'diffie-hellman-group-exchange-sha256', [{public_keys,dh}, {hashs,sha256}]}, + {'diffie-hellman-group-exchange-sha1', [{public_keys,dh}, {hashs,sha}]}, + {'ecdh-sha2-nistp521', [{public_keys,ecdh}, {ec_curve,secp521r1}, {hashs,sha512}]}, + {'diffie-hellman-group1-sha1', [{public_keys,dh}, {hashs,sha}]} + ]); +supported_algorithms(public_key) -> + select_crypto_supported( + [{'ecdsa-sha2-nistp256', [{public_keys,ecdsa}, {hashs,sha256}, {ec_curve,secp256r1}]}, + {'ecdsa-sha2-nistp384', [{public_keys,ecdsa}, {hashs,sha384}, {ec_curve,secp384r1}]}, + {'ecdsa-sha2-nistp521', [{public_keys,ecdsa}, {hashs,sha512}, {ec_curve,secp521r1}]}, + {'ssh-rsa', [{public_keys,rsa}, {hashs,sha} ]}, + {'ssh-dss', [{public_keys,dss}, {hashs,sha} ]} + ]); + +supported_algorithms(cipher) -> + same( + select_crypto_supported( + [{'aes256-ctr', [{ciphers,{aes_ctr,256}}]}, + {'aes192-ctr', [{ciphers,{aes_ctr,192}}]}, + {'aes128-ctr', [{ciphers,{aes_ctr,128}}]}, + {'aes128-cbc', [{ciphers,aes_cbc128}]}, + {'[email protected]', [{ciphers,{aes_gcm,128}}]}, + {'[email protected]', [{ciphers,{aes_gcm,256}}]}, + {'AEAD_AES_128_GCM', [{ciphers,{aes_gcm,128}}]}, + {'AEAD_AES_256_GCM', [{ciphers,{aes_gcm,256}}]}, + {'3des-cbc', [{ciphers,des3_cbc}]} + ] + )); +supported_algorithms(mac) -> + same( + select_crypto_supported( + [{'hmac-sha2-256', [{hashs,sha256}]}, + {'hmac-sha2-512', [{hashs,sha512}]}, + {'hmac-sha1', [{hashs,sha}]}, + {'AEAD_AES_128_GCM', [{ciphers,{aes_gcm,128}}]}, + {'AEAD_AES_256_GCM', [{ciphers,{aes_gcm,256}}]} + ] + )); +supported_algorithms(compression) -> + same(['none', + '[email protected]', + 'zlib' + ]). + +%%%---------------------------------------------------------------------------- versions(client, Options)-> Vsn = proplists:get_value(vsn, Options, ?DEFAULT_CLIENT_VERSION), - Version = format_version(Vsn), - {Vsn, Version}; + {Vsn, format_version(Vsn, software_version(Options))}; versions(server, Options) -> Vsn = proplists:get_value(vsn, Options, ?DEFAULT_SERVER_VERSION), - Version = format_version(Vsn), - {Vsn, Version}. + {Vsn, format_version(Vsn, software_version(Options))}. + +software_version(Options) -> + case proplists:get_value(id_string, Options) of + undefined -> + "Erlang"++ssh_vsn(); + {random,Nlo,Nup} -> + random_id(Nlo,Nup); + ID -> + ID + end. + +ssh_vsn() -> + try {ok,L} = application:get_all_key(ssh), + proplists:get_value(vsn,L,"") + of + "" -> ""; + VSN when is_list(VSN) -> "/" ++ VSN; + _ -> "" + catch + _:_ -> "" + end. + +random_id(Nlo, Nup) -> + [crypto:rand_uniform($a,$z+1) || _<- lists:duplicate(crypto:rand_uniform(Nlo,Nup+1),x) ]. hello_version_msg(Data) -> [Data,"\r\n"]. @@ -57,12 +171,6 @@ hello_version_msg(Data) -> next_seqnum(SeqNum) -> (SeqNum + 1) band 16#ffffffff. -decrypt_first_block(Bin, #ssh{decrypt_block_size = BlockSize} = Ssh0) -> - <<EncBlock:BlockSize/binary, EncData/binary>> = Bin, - {Ssh, <<?UINT32(PacketLen), _/binary>> = DecData} = - decrypt(Ssh0, EncBlock), - {Ssh, PacketLen, DecData, EncData}. - decrypt_blocks(Bin, Length, Ssh0) -> <<EncBlocks:Length/binary, EncData/binary>> = Bin, {Ssh, DecData} = decrypt(Ssh0, EncBlocks), @@ -77,21 +185,26 @@ is_valid_mac(Mac, Data, #ssh{recv_mac = Algorithm, yes_no(Ssh, Prompt) -> (Ssh#ssh.io_cb):yes_no(Prompt, Ssh). -format_version({Major,Minor}) -> +format_version({Major,Minor}, SoftwareVersion) -> "SSH-" ++ integer_to_list(Major) ++ "." ++ - integer_to_list(Minor) ++ "-Erlang". + integer_to_list(Minor) ++ "-" ++ SoftwareVersion. handle_hello_version(Version) -> - StrVersion = trim_tail(Version), - case string:tokens(Version, "-") of - [_, "2.0" | _] -> - {{2,0}, StrVersion}; - [_, "1.99" | _] -> - {{2,0}, StrVersion}; - [_, "1.3" | _] -> - {{1,3}, StrVersion}; - [_, "1.5" | _] -> - {{1,5}, StrVersion} + try + StrVersion = trim_tail(Version), + case string:tokens(Version, "-") of + [_, "2.0" | _] -> + {{2,0}, StrVersion}; + [_, "1.99" | _] -> + {{2,0}, StrVersion}; + [_, "1.3" | _] -> + {{1,3}, StrVersion}; + [_, "1.5" | _] -> + {{1,5}, StrVersion} + end + catch + error:_ -> + {undefined, "unknown version"} end. key_exchange_init_msg(Ssh0) -> @@ -101,48 +214,45 @@ key_exchange_init_msg(Ssh0) -> kex_init(#ssh{role = Role, opts = Opts, available_host_keys = HostKeyAlgs}) -> Random = ssh_bits:random(16), - Compression = case proplists:get_value(compression, Opts, none) of - openssh_zlib -> ["[email protected]", "none"]; - zlib -> ["zlib", "none"]; - none -> ["none", "zlib"] - end, - kexinit_messsage(Role, Random, Compression, HostKeyAlgs). + PrefAlgs = + case proplists:get_value(preferred_algorithms,Opts) of + undefined -> + default_algorithms(); + Algs0 -> + Algs0 + end, + kexinit_message(Role, Random, PrefAlgs, HostKeyAlgs). key_init(client, Ssh, Value) -> Ssh#ssh{c_keyinit = Value}; key_init(server, Ssh, Value) -> Ssh#ssh{s_keyinit = Value}. -kexinit_messsage(client, Random, Compression, HostKeyAlgs) -> - #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"], - compression_algorithms_client_to_server = Compression, - compression_algorithms_server_to_client = Compression, - languages_client_to_server = [], - languages_server_to_client = [] - }; -kexinit_messsage(server, Random, Compression, HostKeyAlgs) -> +kexinit_message(_Role, Random, Algs, HostKeyAlgs) -> #ssh_msg_kexinit{ cookie = Random, - kex_algorithms = ["diffie-hellman-group1-sha1"], + kex_algorithms = to_strings( get_algs(kex,Algs) ), 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"], - compression_algorithms_client_to_server = Compression, - compression_algorithms_server_to_client = Compression, + encryption_algorithms_client_to_server = c2s(cipher,Algs), + encryption_algorithms_server_to_client = s2c(cipher,Algs), + mac_algorithms_client_to_server = c2s(mac,Algs), + mac_algorithms_server_to_client = s2c(mac,Algs), + compression_algorithms_client_to_server = c2s(compression,Algs), + compression_algorithms_server_to_client = s2c(compression,Algs), languages_client_to_server = [], languages_server_to_client = [] }. +c2s(Key, Algs) -> x2y(client2server, Key, Algs). +s2c(Key, Algs) -> x2y(server2client, Key, Algs). + +x2y(DirectionKey, Key, Algs) -> to_strings(proplists:get_value(DirectionKey, get_algs(Key,Algs))). + +get_algs(Key, Algs) -> proplists:get_value(Key, Algs, default_algorithms(Key)). + +to_strings(L) -> lists:map(fun erlang:atom_to_list/1, L). + new_keys_message(Ssh0) -> {SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0), @@ -157,136 +267,411 @@ handle_kexinit_msg(#ssh_msg_kexinit{} = CounterPart, #ssh_msg_kexinit{} = Own, Ssh0#ssh{algorithms = Algoritms}); _ -> %% TODO: Correct code? - throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, description = "Selection of key exchange" " algorithm failed", - language = "en"}) + language = ""}) end; handle_kexinit_msg(#ssh_msg_kexinit{} = CounterPart, #ssh_msg_kexinit{} = Own, #ssh{role = server} = Ssh) -> {ok, Algoritms} = select_algorithm(server, CounterPart, Own), - {ok, Ssh#ssh{algorithms = Algoritms}}. + case verify_algorithm(Algoritms) of + true -> + {ok, Ssh#ssh{algorithms = Algoritms}}; + _ -> + throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + description = "Selection of key exchange" + " algorithm failed", + language = ""}) + end. %% TODO: diffie-hellman-group14-sha1 should also be supported. %% Maybe check more things ... -verify_algorithm(#alg{kex = 'diffie-hellman-group1-sha1'}) -> - true; -verify_algorithm(#alg{kex = 'diffie-hellman-group-exchange-sha1'}) -> - true; -verify_algorithm(_) -> - false. -key_exchange_first_msg('diffie-hellman-group1-sha1', Ssh0) -> - {G, P} = dh_group1(), - {Private, Public} = dh_gen_key(G, P, 1024), +verify_algorithm(#alg{kex = undefined}) -> false; +verify_algorithm(#alg{hkey = undefined}) -> false; +verify_algorithm(#alg{send_mac = undefined}) -> false; +verify_algorithm(#alg{recv_mac = undefined}) -> false; +verify_algorithm(#alg{encrypt = undefined}) -> false; +verify_algorithm(#alg{decrypt = undefined}) -> false; +verify_algorithm(#alg{compress = undefined}) -> false; +verify_algorithm(#alg{decompress = undefined}) -> false; +verify_algorithm(#alg{kex = Kex}) -> lists:member(Kex, supported_algorithms(kex)). + +%%%---------------------------------------------------------------- +%%% +%%% Key exchange initialization +%%% +key_exchange_first_msg(Kex, Ssh0) when Kex == 'diffie-hellman-group1-sha1' ; + Kex == 'diffie-hellman-group14-sha1' -> + {G, P} = dh_group(Kex), + {Public, Private} = generate_key(dh, [P,G]), {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) -> - Min = ?DEFAULT_DH_GROUP_MIN, - NBits = ?DEFAULT_DH_GROUP_NBITS, - Max = ?DEFAULT_DH_GROUP_MAX, +key_exchange_first_msg(Kex, Ssh0=#ssh{opts=Opts}) when Kex == 'diffie-hellman-group-exchange-sha1' ; + Kex == 'diffie-hellman-group-exchange-sha256' -> + {Min,NBits,Max} = + proplists:get_value(dh_gex_limits, Opts, {?DEFAULT_DH_GROUP_MIN, + ?DEFAULT_DH_GROUP_NBITS, + ?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}}}. - - -handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Ssh0) -> - {G, P} = dh_group1(), - {Private, Public} = dh_gen_key(G, P, 1024), - K = ssh_math:ipow(E, Private, P), - Key = get_host_key(Ssh0), - H = kex_h(Ssh0, Key, E, Public, K), - H_SIG = sign_host_key(Ssh0, Key, H), - {SshPacket, Ssh1} = ssh_packet(#ssh_msg_kexdh_reply{public_host_key = Key, - 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)}}. + Ssh1#ssh{keyex_info = {Min, Max, NBits}}}; + +key_exchange_first_msg(Kex, Ssh0) when Kex == 'ecdh-sha2-nistp256' ; + Kex == 'ecdh-sha2-nistp384' ; + Kex == 'ecdh-sha2-nistp521' -> + Curve = ecdh_curve(Kex), + {Public, Private} = generate_key(ecdh, Curve), + {SshPacket, Ssh1} = ssh_packet(#ssh_msg_kex_ecdh_init{q_c=Public}, Ssh0), + {ok, SshPacket, + Ssh1#ssh{keyex_key = {{Public,Private},Curve}}}. + +%%%---------------------------------------------------------------- +%%% +%%% diffie-hellman-group1-sha1 +%%% diffie-hellman-group14-sha1 +%%% +handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, + Ssh0 = #ssh{algorithms = #alg{kex=Kex}}) -> + %% server + {G, P} = dh_group(Kex), + if + 1=<E, E=<(P-1) -> + {Public, Private} = generate_key(dh, [P,G]), + K = compute_key(dh, E, Private, [P,G]), + MyPrivHostKey = get_host_key(Ssh0), + MyPubHostKey = extract_public_key(MyPrivHostKey), + H = kex_h(Ssh0, MyPubHostKey, E, Public, K), + H_SIG = sign_host_key(Ssh0, MyPrivHostKey, H), + {SshPacket, Ssh1} = + ssh_packet(#ssh_msg_kexdh_reply{public_host_key = MyPubHostKey, + 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 -> + 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 = PeerPubHostKey, + f = F, + h_sig = H_SIG}, + #ssh{keyex_key = {{Private, Public}, {G, P}}} = Ssh0) -> + %% client + if + 1=<F, F=<(P-1)-> + K = compute_key(dh, F, Private, [P,G]), + H = kex_h(Ssh0, PeerPubHostKey, Public, F, K), + + case verify_host_key(Ssh0, PeerPubHostKey, 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 = Min0, + n = NBits, + max = Max0}, + Ssh0=#ssh{opts=Opts}) when Min0=<NBits, NBits=<Max0 -> + %% server + {Min, Max} = adjust_gex_min_max(Min0, Max0, Opts), + case public_key:dh_gex_group(Min, NBits, Max, + proplists:get_value(dh_gex_groups,Opts)) of + {ok, {_Sz, {G,P}}} -> + {Public, Private} = generate_key(dh, [P,G]), + {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} + }}; + {error,_} -> + throw(#ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + description = "No possible diffie-hellman-group-exchange group found", + language = ""}) + end; + +handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request_old{n = NBits}, + Ssh0=#ssh{opts=Opts}) -> + %% server + %% + %% This message was in the draft-00 of rfc4419 + %% (https://tools.ietf.org/html/draft-ietf-secsh-dh-group-exchange-00) + %% In later drafts and the rfc is "is used for backward compatibility". + %% Unfortunatly the rfc does not specify how to treat the parameter n + %% if there is no group of that modulus length :( + %% The draft-00 however specifies that n is the "... number of bits + %% the subgroup should have at least". + %% Further, it says that "Servers and clients SHOULD support groups + %% with a modulus length of k bits, where 1024 <= k <= 8192." + %% + Min0 = NBits, + Max0 = 8192, + {Min, Max} = adjust_gex_min_max(Min0, Max0, Opts), + case public_key:dh_gex_group(Min, NBits, Max, + proplists:get_value(dh_gex_groups,Opts)) of + {ok, {_Sz, {G,P}}} -> + {Public, Private} = generate_key(dh, [P,G]), + {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 = {-1, -1, NBits} % flag for kex_h hash calc + }}; + {error,_} -> + throw(#ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + description = "No possible diffie-hellman-group-exchange group found", + language = ""}) + end; + +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 = ""} + }). + + +adjust_gex_min_max(Min0, Max0, Opts) -> + case proplists:get_value(dh_gex_limits, Opts) of + undefined -> + {Min0, Max0}; + {Min1, Max1} -> + Min2 = max(Min0, Min1), + Max2 = min(Max0, Max1), + if + Min2 =< Max2 -> + {Min2, Max2}; + Max2 < Min2 -> + throw(#ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + description = "No possible diffie-hellman-group-exchange group possible", + language = ""}) + end + 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), + %% client + {Public, Private} = generate_key(dh, [P,G]), {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 = compute_key(dh, E, Private, [P,G]), + if + 1<K, K<(P-1) -> + MyPrivHostKey = get_host_key(Ssh0), + MyPubHostKey = extract_public_key(MyPrivHostKey), + H = kex_h(Ssh0, MyPubHostKey, Min, NBits, Max, P, G, E, Public, K), + H_SIG = sign_host_key(Ssh0, MyPrivHostKey, H), + {SshPacket, Ssh} = + ssh_packet(#ssh_msg_kex_dh_gex_reply{public_host_key = MyPubHostKey, + 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 = PeerPubHostKey, + 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 = compute_key(dh, F, Private, [P,G]), + if + 1<K, K<(P-1) -> + H = kex_h(Ssh0, PeerPubHostKey, Min, NBits, Max, P, G, Public, F, K), + + case verify_host_key(Ssh0, PeerPubHostKey, 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. + +%%%---------------------------------------------------------------- +%%% +%%% diffie-hellman-ecdh-sha2-* +%%% +handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, + Ssh0 = #ssh{algorithms = #alg{kex=Kex}}) -> + %% at server + Curve = ecdh_curve(Kex), + {MyPublic, MyPrivate} = generate_key(ecdh, Curve), + try + compute_key(ecdh, PeerPublic, MyPrivate, Curve) + of + K -> + MyPrivHostKey = get_host_key(Ssh0), + MyPubHostKey = extract_public_key(MyPrivHostKey), + H = kex_h(Ssh0, Curve, MyPubHostKey, PeerPublic, MyPublic, K), + H_SIG = sign_host_key(Ssh0, MyPrivHostKey, H), + {SshPacket, Ssh1} = + ssh_packet(#ssh_msg_kex_ecdh_reply{public_host_key = MyPubHostKey, + q_s = MyPublic, + h_sig = H_SIG}, + Ssh0), + {ok, SshPacket, Ssh1#ssh{keyex_key = {{MyPublic,MyPrivate},Curve}, + shared_secret = K, + exchanged_hash = H, + session_id = sid(Ssh1, H)}} + catch + _:_ -> + throw({{error,invalid_peer_public_key}, + #ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + description = "Peer ECDH public key is invalid", + language = ""} + }) + end. + +handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey, + q_s = PeerPublic, + h_sig = H_SIG}, + #ssh{keyex_key = {{MyPublic,MyPrivate}, Curve}} = Ssh0 + ) -> + %% at client + try + compute_key(ecdh, PeerPublic, MyPrivate, Curve) + of + K -> + H = kex_h(Ssh0, Curve, PeerPubHostKey, MyPublic, PeerPublic, K), + case verify_host_key(Ssh0, PeerPubHostKey, 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 = ""} + }) + end + catch + _:_ -> + throw({{error,invalid_peer_public_key}, + #ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + description = "Peer ECDH public key is invalid", + language = ""} + }) + end. + + +%%%---------------------------------------------------------------- handle_new_keys(#ssh_msg_newkeys{}, Ssh0) -> try install_alg(Ssh0) of #ssh{} = Ssh -> {ok, Ssh} catch - error:_Error -> %% TODO: Throw earlier .... + _C:_Error -> %% TODO: Throw earlier .... throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, description = "Install alg failed", 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) -> - 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_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; @@ -300,33 +685,49 @@ get_host_key(SSH) -> #ssh{key_cb = Mod, opts = Opts, algorithms = ALG} = SSH, case Mod:host_key(ALG#alg.hkey, Opts) of - {ok, #'RSAPrivateKey'{} = Key} -> - Key; - {ok, #'DSAPrivateKey'{} = Key} -> - Key; + {ok, #'RSAPrivateKey'{} = Key} -> Key; + {ok, #'DSAPrivateKey'{} = Key} -> Key; + {ok, #'ECPrivateKey'{} = Key} -> Key; Result -> exit({error, {Result, unsupported_key_type}}) end. -sign_host_key(_Ssh, #'RSAPrivateKey'{} = Private, H) -> - Hash = sha, %% Option ?! - _Signature = sign(H, Hash, Private); -sign_host_key(_Ssh, #'DSAPrivateKey'{} = Private, H) -> - Hash = sha, %% Option ?! - _RawSignature = sign(H, Hash, Private). +sign_host_key(_Ssh, PrivateKey, H) -> + sign(H, sign_host_key_sha(PrivateKey), PrivateKey). + +sign_host_key_sha(#'ECPrivateKey'{parameters = {namedCurve,OID}}) -> sha(OID); +sign_host_key_sha(#'RSAPrivateKey'{}) -> sha; +sign_host_key_sha(#'DSAPrivateKey'{}) -> sha. + + +extract_public_key(#'RSAPrivateKey'{modulus = N, publicExponent = E}) -> + #'RSAPublicKey'{modulus = N, publicExponent = E}; +extract_public_key(#'DSAPrivateKey'{y = Y, p = P, q = Q, g = G}) -> + {Y, #'Dss-Parms'{p=P, q=Q, g=G}}; +extract_public_key(#'ECPrivateKey'{parameters = {namedCurve,OID}, + publicKey = Q}) -> + {#'ECPoint'{point=Q}, {namedCurve,OID}}. + verify_host_key(SSH, PublicKey, Digest, Signature) -> - case verify(Digest, sha, Signature, PublicKey) of + case verify(Digest, host_key_sha(PublicKey), Signature, PublicKey) of false -> {error, bad_signature}; true -> known_host_key(SSH, PublicKey, public_algo(PublicKey)) end. -public_algo(#'RSAPublicKey'{}) -> - 'ssh-rsa'; -public_algo({_, #'Dss-Parms'{}}) -> - 'ssh-dss'. + +host_key_sha(#'RSAPublicKey'{}) -> sha; +host_key_sha({_, #'Dss-Parms'{}}) -> sha; +host_key_sha({#'ECPoint'{},{namedCurve,OID}}) -> sha(OID). + +public_algo(#'RSAPublicKey'{}) -> 'ssh-rsa'; +public_algo({_, #'Dss-Parms'{}}) -> 'ssh-dss'; +public_algo({#'ECPoint'{},{namedCurve,OID}}) -> + Curve = public_key:oid2ssh_curvename(OID), + list_to_atom("ecdsa-sha2-" ++ binary_to_list(Curve)). + accepted_host(Ssh, PeerName, Opts) -> case proplists:get_value(silently_accept_hosts, Opts, false) of @@ -359,8 +760,12 @@ known_host_key(#ssh{opts = Opts, key_cb = Mod, peer = Peer} = Ssh, %% The first algorithm in each list MUST be the preferred (guessed) %% algorithm. Each string MUST contain at least one algorithm name. select_algorithm(Role, Client, Server) -> - {Encrypt, Decrypt} = select_encrypt_decrypt(Role, Client, Server), - {SendMac, RecvMac} = select_send_recv_mac(Role, Client, Server), + {Encrypt0, Decrypt0} = select_encrypt_decrypt(Role, Client, Server), + {SendMac0, RecvMac0} = select_send_recv_mac(Role, Client, Server), + + {Encrypt, SendMac} = aead_gcm_simultan(Encrypt0, SendMac0), + {Decrypt, RecvMac} = aead_gcm_simultan(Decrypt0, RecvMac0), + {Compression, Decompression} = select_compression_decompression(Role, Client, Server), @@ -391,6 +796,38 @@ select_algorithm(Role, Client, Server) -> s_lng = S_Lng}, {ok, Alg}. + +%%% It is an agreed problem with RFC 5674 that if the selection is +%%% Cipher = AEAD_AES_x_GCM and +%%% Mac = AEAD_AES_y_GCM (where x =/= y) +%%% then it is undefined what length should be selected. +%%% +%%% If only one of the two lengths (128,256) is available, I claim that +%%% there is no such ambiguity. + +%%% From https://anongit.mindrot.org/openssh.git/plain/PROTOCOL +%%% (read Nov 20, 2015) +%%% 1.6 transport: AES-GCM +%%% +%%% OpenSSH supports the AES-GCM algorithm as specified in RFC 5647. +%%% Because of problems with the specification of the key exchange +%%% the behaviour of OpenSSH differs from the RFC as follows: +%%% +%%% AES-GCM is only negotiated as the cipher algorithms +%%% "[email protected]" or "[email protected]" and never as +%%% an MAC algorithm. Additionally, if AES-GCM is selected as the cipher +%%% the exchanged MAC algorithms are ignored and there doesn't have to be +%%% a matching MAC. + +aead_gcm_simultan('[email protected]', _) -> {'AEAD_AES_128_GCM', 'AEAD_AES_128_GCM'}; +aead_gcm_simultan('[email protected]', _) -> {'AEAD_AES_256_GCM', 'AEAD_AES_256_GCM'}; +aead_gcm_simultan('AEAD_AES_128_GCM', _) -> {'AEAD_AES_128_GCM', 'AEAD_AES_128_GCM'}; +aead_gcm_simultan('AEAD_AES_256_GCM', _) -> {'AEAD_AES_256_GCM', 'AEAD_AES_256_GCM'}; +aead_gcm_simultan(_, 'AEAD_AES_128_GCM') -> {'AEAD_AES_128_GCM', 'AEAD_AES_128_GCM'}; +aead_gcm_simultan(_, 'AEAD_AES_256_GCM') -> {'AEAD_AES_256_GCM', 'AEAD_AES_256_GCM'}; +aead_gcm_simultan(Cipher, Mac) -> {Cipher,Mac}. + + select_encrypt_decrypt(client, Client, Server) -> Encrypt = select(Client#ssh_msg_kexinit.encryption_algorithms_client_to_server, @@ -425,18 +862,18 @@ select_compression_decompression(client, Client, Server) -> Compression = select(Client#ssh_msg_kexinit.compression_algorithms_client_to_server, Server#ssh_msg_kexinit.compression_algorithms_client_to_server), - Decomprssion = + Decompression = select(Client#ssh_msg_kexinit.compression_algorithms_server_to_client, Server#ssh_msg_kexinit.compression_algorithms_server_to_client), - {Compression, Decomprssion}; + {Compression, Decompression}; select_compression_decompression(server, Client, Server) -> - Decomprssion = + Decompression = select(Client#ssh_msg_kexinit.compression_algorithms_client_to_server, Server#ssh_msg_kexinit.compression_algorithms_client_to_server), Compression = select(Client#ssh_msg_kexinit.compression_algorithms_server_to_client, Server#ssh_msg_kexinit.compression_algorithms_server_to_client), - {Compression, Decomprssion}. + {Compression, Decompression}. install_alg(SSH) -> SSH1 = alg_final(SSH), @@ -478,10 +915,16 @@ alg_final(SSH0) -> {ok,SSH6} = decompress_final(SSH5), SSH6. -select_all(CL, SL) -> +select_all(CL, SL) when length(CL) + length(SL) < ?MAX_NUM_ALGORITHMS -> A = CL -- SL, %% algortihms only used by client %% algorithms used by client and server (client pref) - lists:map(fun(ALG) -> list_to_atom(ALG) end, (CL -- A)). + lists:map(fun(ALG) -> list_to_atom(ALG) end, (CL -- A)); +select_all(CL, SL) -> + Err = lists:concat(["Received too many algorithms (",length(CL),"+",length(SL)," >= ",?MAX_NUM_ALGORITHMS,")."]), + throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + description = Err, + language = ""}). + select([], []) -> none; @@ -501,58 +944,147 @@ ssh_packet(Msg, Ssh) -> BinMsg = ssh_message:encode(Msg), pack(BinMsg, Ssh). -pack(Data0, #ssh{encrypt_block_size = BlockSize, - send_sequence = SeqNum, send_mac = MacAlg, - send_mac_key = MacKey} - = Ssh0) when is_binary(Data0) -> - {Ssh1, Data} = compress(Ssh0, Data0), - PL = (BlockSize - ((4 + 1 + size(Data)) rem BlockSize)) rem BlockSize, - PaddingLen = if PL < 4 -> PL + BlockSize; - true -> PL - end, - Padding = ssh_bits:random(PaddingLen), - PacketLen = 1 + PaddingLen + size(Data), - PacketData = <<?UINT32(PacketLen),?BYTE(PaddingLen), - Data/binary, Padding/binary>>, - {Ssh2, EncPacket} = encrypt(Ssh1, PacketData), - MAC = mac(MacAlg, MacKey, SeqNum, PacketData), - Packet = [EncPacket, MAC], - Ssh = Ssh2#ssh{send_sequence = (SeqNum+1) band 16#ffffffff}, - {Packet, Ssh}. - -unpack(EncodedSoFar, ReminingLenght, #ssh{recv_mac_size = MacSize} = Ssh0) -> - SshLength = ReminingLenght - MacSize, - {NoMac, Mac, Rest} = case MacSize of - 0 -> - <<NoMac0:SshLength/binary, - Rest0/binary>> = EncodedSoFar, - {NoMac0, <<>>, Rest0}; - _ -> - <<NoMac0:SshLength/binary, - Mac0:MacSize/binary, - Rest0/binary>> = EncodedSoFar, - {NoMac0, Mac0, Rest0} - end, - {Ssh1, DecData, <<>>} = - case SshLength of - 0 -> - {Ssh0, <<>>, <<>>}; - _ -> - decrypt_blocks(NoMac, SshLength, Ssh0) +pack(Data, Ssh=#ssh{}) -> + pack(Data, Ssh, 0). + +%%% Note: pack/3 is only to be called from tests that wants +%%% to deliberetly send packets with wrong PacketLength! +%%% Use pack/2 for all other purposes! +pack(PlainText, + #ssh{send_sequence = SeqNum, + send_mac = MacAlg, + send_mac_key = MacKey, + encrypt = CryptoAlg} = Ssh0, PacketLenDeviationForTests) when is_binary(PlainText) -> + + {Ssh1, CompressedPlainText} = compress(Ssh0, PlainText), + {EcryptedPacket, MAC, Ssh3} = + case pkt_type(CryptoAlg) of + common -> + PaddingLen = padding_length(4+1+size(CompressedPlainText), Ssh0), + Padding = ssh_bits:random(PaddingLen), + PlainPacketLen = 1 + PaddingLen + size(CompressedPlainText) + PacketLenDeviationForTests, + PlainPacketData = <<?UINT32(PlainPacketLen),?BYTE(PaddingLen), CompressedPlainText/binary, Padding/binary>>, + {Ssh2, EcryptedPacket0} = encrypt(Ssh1, PlainPacketData), + MAC0 = mac(MacAlg, MacKey, SeqNum, PlainPacketData), + {EcryptedPacket0, MAC0, Ssh2}; + aead -> + PaddingLen = padding_length(1+size(CompressedPlainText), Ssh0), + Padding = ssh_bits:random(PaddingLen), + PlainPacketLen = 1 + PaddingLen + size(CompressedPlainText) + PacketLenDeviationForTests, + PlainPacketData = <<?BYTE(PaddingLen), CompressedPlainText/binary, Padding/binary>>, + {Ssh2, {EcryptedPacket0,MAC0}} = encrypt(Ssh1, {<<?UINT32(PlainPacketLen)>>,PlainPacketData}), + {<<?UINT32(PlainPacketLen),EcryptedPacket0/binary>>, MAC0, Ssh2} end, - {Ssh1, DecData, Rest, Mac}. + FinalPacket = [EcryptedPacket, MAC], + Ssh = Ssh3#ssh{send_sequence = (SeqNum+1) band 16#ffffffff}, + {FinalPacket, Ssh}. + + +padding_length(Size, #ssh{encrypt_block_size = BlockSize, + random_length_padding = RandomLengthPadding}) -> + PL = (BlockSize - (Size rem BlockSize)) rem BlockSize, + MinPaddingLen = if PL < 4 -> PL + BlockSize; + true -> PL + end, + PadBlockSize = max(BlockSize,4), + MaxExtraBlocks = (max(RandomLengthPadding,MinPaddingLen) - MinPaddingLen) div PadBlockSize, + ExtraPaddingLen = try crypto:rand_uniform(0,MaxExtraBlocks)*PadBlockSize + catch _:_ -> 0 + end, + MinPaddingLen + ExtraPaddingLen. + + + +handle_packet_part(<<>>, Encrypted0, undefined, #ssh{decrypt = CryptoAlg} = Ssh0) -> + %% New ssh packet + case get_length(pkt_type(CryptoAlg), Encrypted0, Ssh0) of + get_more -> + %% too short to get the length + {get_more, <<>>, Encrypted0, undefined, Ssh0}; + + {ok, PacketLen, _, _, _} when PacketLen > ?SSH_MAX_PACKET_SIZE -> + %% far too long message than expected + {error, {exceeds_max_size,PacketLen}}; + + {ok, PacketLen, Decrypted, Encrypted1, + #ssh{recv_mac_size = MacSize} = Ssh1} -> + %% enough bytes so we got the length and can calculate how many + %% more bytes to expect for a full packet + TotalNeeded = (4 + PacketLen + MacSize), + handle_packet_part(Decrypted, Encrypted1, TotalNeeded, Ssh1) + end; + +handle_packet_part(DecryptedPfx, EncryptedBuffer, TotalNeeded, Ssh0) + when (size(DecryptedPfx)+size(EncryptedBuffer)) < TotalNeeded -> + %% need more bytes to finalize the packet + {get_more, DecryptedPfx, EncryptedBuffer, TotalNeeded, Ssh0}; + +handle_packet_part(DecryptedPfx, EncryptedBuffer, TotalNeeded, + #ssh{recv_mac_size = MacSize, + decrypt = CryptoAlg} = Ssh0) -> + %% enough bytes to decode the packet. + DecryptLen = TotalNeeded - size(DecryptedPfx) - MacSize, + <<EncryptedSfx:DecryptLen/binary, Mac:MacSize/binary, NextPacketBytes/binary>> = EncryptedBuffer, + case pkt_type(CryptoAlg) of + common -> + {Ssh1, DecryptedSfx} = decrypt(Ssh0, EncryptedSfx), + DecryptedPacket = <<DecryptedPfx/binary, DecryptedSfx/binary>>, + case is_valid_mac(Mac, DecryptedPacket, Ssh1) of + false -> + {bad_mac, Ssh1}; + true -> + {Ssh, DecompressedPayload} = decompress(Ssh1, payload(DecryptedPacket)), + {decoded, DecompressedPayload, NextPacketBytes, Ssh} + end; + aead -> + PacketLenBin = DecryptedPfx, + case decrypt(Ssh0, {PacketLenBin,EncryptedSfx,Mac}) of + {Ssh1, error} -> + {bad_mac, Ssh1}; + {Ssh1, DecryptedSfx} -> + DecryptedPacket = <<DecryptedPfx/binary, DecryptedSfx/binary>>, + {Ssh, DecompressedPayload} = decompress(Ssh1, payload(DecryptedPacket)), + {decoded, DecompressedPayload, NextPacketBytes, Ssh} + end + end. + + +get_length(common, EncryptedBuffer, #ssh{decrypt_block_size = BlockSize} = Ssh0) -> + case size(EncryptedBuffer) >= erlang:max(8, BlockSize) of + true -> + <<EncBlock:BlockSize/binary, EncryptedRest/binary>> = EncryptedBuffer, + {Ssh, + <<?UINT32(PacketLen),_/binary>> = Decrypted} = decrypt(Ssh0, EncBlock), + {ok, PacketLen, Decrypted, EncryptedRest, Ssh}; + false -> + get_more + end; +get_length(aead, EncryptedBuffer, Ssh) -> + case size(EncryptedBuffer) >= 4 of + true -> + <<?UINT32(PacketLen), EncryptedRest/binary>> = EncryptedBuffer, + {ok, PacketLen, <<?UINT32(PacketLen)>>, EncryptedRest, Ssh}; + false -> + get_more + end. + +pkt_type('AEAD_AES_128_GCM') -> aead; +pkt_type('AEAD_AES_256_GCM') -> aead; +pkt_type(_) -> common. -msg_data(PacketData) -> - <<Len:32, PaddingLen:8, _/binary>> = PacketData, - DataLen = Len - PaddingLen - 1, - <<_:32, _:8, Data:DataLen/binary, - _:PaddingLen/binary>> = PacketData, - Data. +payload(<<PacketLen:32, PaddingLen:8, PayloadAndPadding/binary>>) -> + PayloadLen = PacketLen - PaddingLen - 1, + <<Payload:PayloadLen/binary, _/binary>> = PayloadAndPadding, + Payload. sign(SigData, Hash, #'DSAPrivateKey'{} = Key) -> DerSignature = public_key:sign(SigData, Hash, Key), #'Dss-Sig-Value'{r = R, s = S} = public_key:der_decode('Dss-Sig-Value', DerSignature), <<R:160/big-unsigned-integer, S:160/big-unsigned-integer>>; +sign(SigData, Hash, Key = #'ECPrivateKey'{}) -> + DerEncodedSign = public_key:sign(SigData, Hash, Key), + #'ECDSA-Sig-Value'{r=R, s=S} = public_key:der_decode('ECDSA-Sig-Value', DerEncodedSign), + ssh_bits:encode([R,S], [mpint,mpint]); sign(SigData, Hash, Key) -> public_key:sign(SigData, Hash, Key). @@ -560,59 +1092,48 @@ verify(PlainText, Hash, Sig, {_, #'Dss-Parms'{}} = Key) -> <<R:160/big-unsigned-integer, S:160/big-unsigned-integer>> = Sig, Signature = public_key:der_encode('Dss-Sig-Value', #'Dss-Sig-Value'{r = R, s = S}), public_key:verify(PlainText, Hash, Signature, Key); +verify(PlainText, Hash, Sig, {#'ECPoint'{},_} = Key) -> + <<?UINT32(Rlen),R:Rlen/big-signed-integer-unit:8, + ?UINT32(Slen),S:Slen/big-signed-integer-unit:8>> = Sig, + Sval = #'ECDSA-Sig-Value'{r=R, s=S}, + DerEncodedSig = public_key:der_encode('ECDSA-Sig-Value',Sval), + public_key:verify(PlainText, Hash, DerEncodedSig, Key); verify(PlainText, Hash, Sig, Key) -> public_key:verify(PlainText, Hash, Sig, Key). -%% public key algorithms -%% -%% ssh-dss REQUIRED sign Raw DSS Key -%% ssh-rsa RECOMMENDED sign Raw RSA Key -%% x509v3-sign-rsa OPTIONAL sign X.509 certificates (RSA key) -%% x509v3-sign-dss OPTIONAL sign X.509 certificates (DSS key) -%% spki-sign-rsa OPTIONAL sign SPKI certificates (RSA key) -%% spki-sign-dss OPTIONAL sign SPKI certificates (DSS key) -%% pgp-sign-rsa OPTIONAL sign OpenPGP certificates (RSA key) -%% pgp-sign-dss OPTIONAL sign OpenPGP certificates (DSS key) -%% - -%% key exchange -%% -%% diffie-hellman-group1-sha1 REQUIRED -%% -%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%% Encryption %% -%% chiphers -%% -%% 3des-cbc REQUIRED -%% three-key 3DES in CBC mode -%% blowfish-cbc OPTIONAL Blowfish in CBC mode -%% twofish256-cbc OPTIONAL Twofish in CBC mode, -%% with 256-bit key -%% twofish-cbc OPTIONAL alias for "twofish256-cbc" (this -%% is being retained for -%% historical reasons) -%% twofish192-cbc OPTIONAL Twofish with 192-bit key -%% twofish128-cbc OPTIONAL Twofish with 128-bit key -%% aes256-cbc OPTIONAL AES in CBC mode, -%% with 256-bit key -%% aes192-cbc OPTIONAL AES with 192-bit key -%% aes128-cbc RECOMMENDED AES with 128-bit key -%% serpent256-cbc OPTIONAL Serpent in CBC mode, with -%% 256-bit key -%% serpent192-cbc OPTIONAL Serpent with 192-bit key -%% serpent128-cbc OPTIONAL Serpent with 128-bit key -%% arcfour OPTIONAL the ARCFOUR stream cipher -%% idea-cbc OPTIONAL IDEA in CBC mode -%% cast128-cbc OPTIONAL CAST-128 in CBC mode -%% none OPTIONAL no encryption; NOT RECOMMENDED +%% Encryption %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% encrypt_init(#ssh{encrypt = none} = Ssh) -> {ok, Ssh}; +encrypt_init(#ssh{encrypt = 'AEAD_AES_128_GCM', role = client} = Ssh) -> + IV = hash(Ssh, "A", 12*8), + <<K:16/binary>> = hash(Ssh, "C", 128), + {ok, Ssh#ssh{encrypt_keys = K, + encrypt_block_size = 16, + encrypt_ctx = IV}}; +encrypt_init(#ssh{encrypt = 'AEAD_AES_128_GCM', role = server} = Ssh) -> + IV = hash(Ssh, "B", 12*8), + <<K:16/binary>> = hash(Ssh, "D", 128), + {ok, Ssh#ssh{encrypt_keys = K, + encrypt_block_size = 16, + encrypt_ctx = IV}}; +encrypt_init(#ssh{encrypt = 'AEAD_AES_256_GCM', role = client} = Ssh) -> + IV = hash(Ssh, "A", 12*8), + <<K:32/binary>> = hash(Ssh, "C", 256), + {ok, Ssh#ssh{encrypt_keys = K, + encrypt_block_size = 16, + encrypt_ctx = IV}}; +encrypt_init(#ssh{encrypt = 'AEAD_AES_256_GCM', role = server} = Ssh) -> + IV = hash(Ssh, "B", 12*8), + <<K:32/binary>> = hash(Ssh, "D", 256), + {ok, Ssh#ssh{encrypt_keys = K, + encrypt_block_size = 16, + encrypt_ctx = IV}}; encrypt_init(#ssh{encrypt = '3des-cbc', role = client} = Ssh) -> IV = hash(Ssh, "A", 64), <<K1:8/binary, K2:8/binary, K3:8/binary>> = hash(Ssh, "C", 192), @@ -636,7 +1157,49 @@ 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 = 'aes192-ctr', role = client} = Ssh) -> + IV = hash(Ssh, "A", 128), + <<K:24/binary>> = hash(Ssh, "C", 192), + 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 = 'aes256-ctr', role = client} = Ssh) -> + IV = hash(Ssh, "A", 128), + <<K:32/binary>> = hash(Ssh, "C", 256), + 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_init(#ssh{encrypt = 'aes192-ctr', role = server} = Ssh) -> + IV = hash(Ssh, "B", 128), + <<K:24/binary>> = hash(Ssh, "D", 192), + 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 = 'aes256-ctr', role = server} = Ssh) -> + IV = hash(Ssh, "B", 128), + <<K:32/binary>> = hash(Ssh, "D", 256), + 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, @@ -647,6 +1210,18 @@ encrypt_final(Ssh) -> encrypt(#ssh{encrypt = none} = Ssh, Data) -> {Ssh, Data}; +encrypt(#ssh{encrypt = 'AEAD_AES_128_GCM', + encrypt_keys = K, + encrypt_ctx = IV0} = Ssh, Data={_AAD,_Ptext}) -> + Enc = {_Ctext,_Ctag} = crypto:block_encrypt(aes_gcm, K, IV0, Data), + IV = next_gcm_iv(IV0), + {Ssh#ssh{encrypt_ctx = IV}, Enc}; +encrypt(#ssh{encrypt = 'AEAD_AES_256_GCM', + encrypt_keys = K, + encrypt_ctx = IV0} = Ssh, Data={_AAD,_Ptext}) -> + Enc = {_Ctext,_Ctag} = crypto:block_encrypt(aes_gcm, K, IV0, Data), + IV = next_gcm_iv(IV0), + {Ssh#ssh{encrypt_ctx = IV}, Enc}; encrypt(#ssh{encrypt = '3des-cbc', encrypt_keys = {K1,K2,K3}, encrypt_ctx = IV0} = Ssh, Data) -> @@ -658,7 +1233,19 @@ 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}; +encrypt(#ssh{encrypt = 'aes192-ctr', + encrypt_ctx = State0} = Ssh, Data) -> + {State, Enc} = crypto:stream_encrypt(State0,Data), + {Ssh#ssh{encrypt_ctx = State}, Enc}; +encrypt(#ssh{encrypt = 'aes256-ctr', + encrypt_ctx = State0} = Ssh, Data) -> + {State, Enc} = crypto:stream_encrypt(State0,Data), + {Ssh#ssh{encrypt_ctx = State}, Enc}. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @@ -667,6 +1254,30 @@ encrypt(#ssh{encrypt = 'aes128-cbc', decrypt_init(#ssh{decrypt = none} = Ssh) -> {ok, Ssh}; +decrypt_init(#ssh{decrypt = 'AEAD_AES_128_GCM', role = client} = Ssh) -> + IV = hash(Ssh, "B", 12*8), + <<K:16/binary>> = hash(Ssh, "D", 128), + {ok, Ssh#ssh{decrypt_keys = K, + decrypt_block_size = 16, + decrypt_ctx = IV}}; +decrypt_init(#ssh{decrypt = 'AEAD_AES_128_GCM', role = server} = Ssh) -> + IV = hash(Ssh, "A", 12*8), + <<K:16/binary>> = hash(Ssh, "C", 128), + {ok, Ssh#ssh{decrypt_keys = K, + decrypt_block_size = 16, + decrypt_ctx = IV}}; +decrypt_init(#ssh{decrypt = 'AEAD_AES_256_GCM', role = client} = Ssh) -> + IV = hash(Ssh, "B", 12*8), + <<K:32/binary>> = hash(Ssh, "D", 256), + {ok, Ssh#ssh{decrypt_keys = K, + decrypt_block_size = 16, + decrypt_ctx = IV}}; +decrypt_init(#ssh{decrypt = 'AEAD_AES_256_GCM', role = server} = Ssh) -> + IV = hash(Ssh, "A", 12*8), + <<K:32/binary>> = hash(Ssh, "C", 256), + {ok, Ssh#ssh{decrypt_keys = K, + decrypt_block_size = 16, + decrypt_ctx = IV}}; decrypt_init(#ssh{decrypt = '3des-cbc', role = client} = Ssh) -> {IV, KD} = {hash(Ssh, "B", 64), hash(Ssh, "D", 192)}, @@ -690,7 +1301,49 @@ 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 = 'aes192-ctr', role = client} = Ssh) -> + IV = hash(Ssh, "B", 128), + <<K:24/binary>> = hash(Ssh, "D", 192), + 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 = 'aes256-ctr', role = client} = Ssh) -> + IV = hash(Ssh, "B", 128), + <<K:32/binary>> = hash(Ssh, "D", 256), + 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_init(#ssh{decrypt = 'aes192-ctr', role = server} = Ssh) -> + IV = hash(Ssh, "A", 128), + <<K:24/binary>> = hash(Ssh, "C", 192), + 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 = 'aes256-ctr', role = server} = Ssh) -> + IV = hash(Ssh, "A", 128), + <<K:32/binary>> = hash(Ssh, "C", 256), + State = crypto:stream_init(aes_ctr, K, IV), + {ok, Ssh#ssh{decrypt_keys = K, + decrypt_block_size = 16, + decrypt_ctx = State}}. decrypt_final(Ssh) -> @@ -699,8 +1352,22 @@ decrypt_final(Ssh) -> decrypt_ctx = undefined, decrypt_block_size = 8}}. +decrypt(Ssh, <<>>) -> + {Ssh, <<>>}; decrypt(#ssh{decrypt = none} = Ssh, Data) -> {Ssh, Data}; +decrypt(#ssh{decrypt = 'AEAD_AES_128_GCM', + decrypt_keys = K, + decrypt_ctx = IV0} = Ssh, Data = {_AAD,_Ctext,_Ctag}) -> + Dec = crypto:block_decrypt(aes_gcm, K, IV0, Data), % Dec = PlainText | error + IV = next_gcm_iv(IV0), + {Ssh#ssh{decrypt_ctx = IV}, Dec}; +decrypt(#ssh{decrypt = 'AEAD_AES_256_GCM', + decrypt_keys = K, + decrypt_ctx = IV0} = Ssh, Data = {_AAD,_Ctext,_Ctag}) -> + Dec = crypto:block_decrypt(aes_gcm, K, IV0, Data), % Dec = PlainText | error + IV = next_gcm_iv(IV0), + {Ssh#ssh{decrypt_ctx = IV}, Dec}; decrypt(#ssh{decrypt = '3des-cbc', decrypt_keys = Keys, decrypt_ctx = IV0} = Ssh, Data) -> {K1, K2, K3} = Keys, @@ -711,7 +1378,23 @@ 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}; +decrypt(#ssh{decrypt = 'aes192-ctr', + decrypt_ctx = State0} = Ssh, Data) -> + {State, Enc} = crypto:stream_decrypt(State0,Data), + {Ssh#ssh{decrypt_ctx = State}, Enc}; +decrypt(#ssh{decrypt = 'aes256-ctr', + decrypt_ctx = State0} = Ssh, Data) -> + {State, Enc} = crypto:stream_decrypt(State0,Data), + {Ssh#ssh{decrypt_ctx = State}, Enc}. + + +next_gcm_iv(<<Fixed:32, InvCtr:64>>) -> <<Fixed:32, (InvCtr+1):64>>. + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% Compression @@ -795,49 +1478,54 @@ decompress(#ssh{decompress = '[email protected]', decompress_ctx = Context, authe {Ssh, list_to_binary(Decompressed)}. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%% MAC calculation %% -%% hmac-sha1 REQUIRED HMAC-SHA1 (digest length = key -%% length = 20) -%% hmac-sha1-96 RECOMMENDED first 96 bits of HMAC-SHA1 (digest -%% length = 12, key length = 20) -%% hmac-md5 OPTIONAL HMAC-MD5 (digest length = key -%% length = 16) -%% hmac-md5-96 OPTIONAL first 96 bits of HMAC-MD5 (digest -%% length = 12, key length = 16) -%% none OPTIONAL no MAC; NOT RECOMMENDED +%% MAC calculation %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% send_mac_init(SSH) -> - case SSH#ssh.role of - client -> - KeySize =mac_key_size(SSH#ssh.send_mac), - Key = hash(SSH, "E", KeySize), - {ok, SSH#ssh { send_mac_key = Key }}; - server -> - KeySize = mac_key_size(SSH#ssh.send_mac), - Key = hash(SSH, "F", KeySize), - {ok, SSH#ssh { send_mac_key = Key }} + case pkt_type(SSH#ssh.send_mac) of + common -> + case SSH#ssh.role of + client -> + KeySize = mac_key_size(SSH#ssh.send_mac), + Key = hash(SSH, "E", KeySize), + {ok, SSH#ssh { send_mac_key = Key }}; + server -> + KeySize = mac_key_size(SSH#ssh.send_mac), + Key = hash(SSH, "F", KeySize), + {ok, SSH#ssh { send_mac_key = Key }} + end; + aead -> + %% Not applicable + {ok, SSH} end. send_mac_final(SSH) -> - {ok, SSH#ssh { send_mac = none, send_mac_key = undefined }}. + {ok, SSH#ssh {send_mac = none, + send_mac_key = undefined }}. + recv_mac_init(SSH) -> - case SSH#ssh.role of - client -> - Key = hash(SSH, "F", mac_key_size(SSH#ssh.recv_mac)), - {ok, SSH#ssh { recv_mac_key = Key }}; - server -> - Key = hash(SSH, "E", mac_key_size(SSH#ssh.recv_mac)), - {ok, SSH#ssh { recv_mac_key = Key }} + case pkt_type(SSH#ssh.recv_mac) of + common -> + case SSH#ssh.role of + client -> + Key = hash(SSH, "F", mac_key_size(SSH#ssh.recv_mac)), + {ok, SSH#ssh { recv_mac_key = Key }}; + server -> + Key = hash(SSH, "E", mac_key_size(SSH#ssh.recv_mac)), + {ok, SSH#ssh { recv_mac_key = Key }} + end; + aead -> + %% Not applicable + {ok, SSH} end. 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]); @@ -846,7 +1534,11 @@ 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]); +mac('hmac-sha2-512', Key, SeqNum, Data) -> + crypto:hmac(sha512, Key, [<<?UINT32(SeqNum)>>, Data]). %% return N hash bytes (HASH) hash(SSH, Char, Bits) -> @@ -854,8 +1546,20 @@ hash(SSH, Char, Bits) -> case SSH#ssh.kex of 'diffie-hellman-group1-sha1' -> fun(Data) -> crypto:hash(sha, Data) end; + 'diffie-hellman-group14-sha1' -> + 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; + + 'ecdh-sha2-nistp256' -> + fun(Data) -> crypto:hash(sha256,Data) end; + 'ecdh-sha2-nistp384' -> + fun(Data) -> crypto:hash(sha384,Data) end; + 'ecdh-sha2-nistp521' -> + fun(Data) -> crypto:hash(sha512,Data) end; _ -> exit({bad_algorithm,SSH#ssh.kex}) end, @@ -879,22 +1583,36 @@ hash(K, H, Ki, N, HASH) -> hash(K, H, <<Ki/binary, Kj/binary>>, N-128, HASH). kex_h(SSH, Key, E, F, K) -> + KeyBin = public_key:ssh_encode(Key, ssh2_pubkey), L = ssh_bits:encode([SSH#ssh.c_version, SSH#ssh.s_version, SSH#ssh.c_keyinit, SSH#ssh.s_keyinit, - ssh_message:encode_host_key(Key), E,F,K], + KeyBin, E,F,K], [string,string,binary,binary,binary, mpint,mpint,mpint]), - crypto:hash(sha,L). - + crypto:hash(sha((SSH#ssh.algorithms)#alg.kex), L). +%% crypto:hash(sha,L). + +kex_h(SSH, Curve, Key, Q_c, Q_s, K) -> + KeyBin = public_key:ssh_encode(Key, ssh2_pubkey), + L = ssh_bits:encode([SSH#ssh.c_version, SSH#ssh.s_version, + SSH#ssh.c_keyinit, SSH#ssh.s_keyinit, + KeyBin, Q_c, Q_s, K], + [string,string,binary,binary,binary, + mpint,mpint,mpint]), + crypto:hash(sha(Curve), L). kex_h(SSH, Key, Min, NBits, Max, Prime, Gen, E, F, K) -> + KeyBin = public_key:ssh_encode(Key, ssh2_pubkey), L = if Min==-1; Max==-1 -> + %% flag from 'ssh_msg_kex_dh_gex_request_old' + %% It was like this before that message was supported, + %% why? Ts = [string,string,binary,binary,binary, uint32, mpint,mpint,mpint,mpint,mpint], ssh_bits:encode([SSH#ssh.c_version,SSH#ssh.s_version, SSH#ssh.c_keyinit,SSH#ssh.s_keyinit, - ssh_message:encode_host_key(Key), NBits, Prime, Gen, E,F,K], + KeyBin, NBits, Prime, Gen, E,F,K], Ts); true -> Ts = [string,string,binary,binary,binary, @@ -902,21 +1620,40 @@ kex_h(SSH, Key, Min, NBits, Max, Prime, Gen, E, F, K) -> mpint,mpint,mpint,mpint,mpint], ssh_bits:encode([SSH#ssh.c_version,SSH#ssh.s_version, SSH#ssh.c_keyinit,SSH#ssh.s_keyinit, - ssh_message:encode_host_key(Key), Min, NBits, Max, + KeyBin, Min, NBits, Max, Prime, Gen, E,F,K], Ts) end, - crypto:hash(sha,L). + crypto:hash(sha((SSH#ssh.algorithms)#alg.kex), L). + +sha(secp256r1) -> sha256; +sha(secp384r1) -> sha384; +sha(secp521r1) -> sha512; +sha('diffie-hellman-group1-sha1') -> sha; +sha('diffie-hellman-group14-sha1') -> sha; +sha('diffie-hellman-group-exchange-sha1') -> sha; +sha('diffie-hellman-group-exchange-sha256') -> sha256; +sha(?'secp256r1') -> sha(secp256r1); +sha(?'secp384r1') -> sha(secp384r1); +sha(?'secp521r1') -> sha(secp521r1). + + 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('hmac-sha2-512')-> 512; 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('hmac-sha2-512') -> 64; +mac_digest_size('AEAD_AES_128_GCM') -> 16; +mac_digest_size('AEAD_AES_256_GCM') -> 16; mac_digest_size(none) -> 0. peer_name({Host, _}) -> @@ -928,12 +1665,91 @@ peer_name({Host, _}) -> %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -dh_group1() -> - {2, 16#FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF}. +dh_group('diffie-hellman-group1-sha1') -> ?dh_group1; +dh_group('diffie-hellman-group14-sha1') -> ?dh_group14. + +%%%---------------------------------------------------------------- +generate_key(Algorithm, Args) -> + {Public,Private} = crypto:generate_key(Algorithm, Args), + {crypto:bytes_to_integer(Public), crypto:bytes_to_integer(Private)}. -dh_gen_key(G, P, _) -> - {Public, Private} = crypto:generate_key(dh, [P, G]), - {crypto:bytes_to_integer(Private), crypto:bytes_to_integer(Public)}. + +compute_key(Algorithm, OthersPublic, MyPrivate, Args) -> + Shared = crypto:compute_key(Algorithm, OthersPublic, MyPrivate, Args), + crypto:bytes_to_integer(Shared). + + +ecdh_curve('ecdh-sha2-nistp256') -> secp256r1; +ecdh_curve('ecdh-sha2-nistp384') -> secp384r1; +ecdh_curve('ecdh-sha2-nistp521') -> secp521r1. + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% +%% Utils for default_algorithms/1 and supported_algorithms/1 +%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +supported_algorithms(Key, [{client2server,BL1},{server2client,BL2}]) -> + [{client2server,As1},{server2client,As2}] = supported_algorithms(Key), + [{client2server,As1--BL1},{server2client,As2--BL2}]; +supported_algorithms(Key, BlackList) -> + supported_algorithms(Key) -- BlackList. + + +select_crypto_supported(L) -> + Sup = [{ec_curve,crypto_supported_curves()} | crypto:supports()], + [Name || {Name,CryptoRequires} <- L, + crypto_supported(CryptoRequires, Sup)]. + +crypto_supported_curves() -> + try crypto:ec_curves() + catch _:_ -> [] + end. + +crypto_supported(Conditions, Supported) -> + lists:all( fun({Tag,CryptoName}) when is_atom(CryptoName) -> + crypto_name_supported(Tag,CryptoName,Supported); + ({Tag,{Name,Len}}) when is_integer(Len) -> + crypto_name_supported(Tag,Name,Supported) andalso + len_supported(Name,Len) + end, Conditions). + +crypto_name_supported(Tag, CryptoName, Supported) -> + lists:member(CryptoName, proplists:get_value(Tag,Supported,[])). + +len_supported(Name, Len) -> + try + case Name of + aes_ctr -> + {_, <<_/binary>>} = + %% Test encryption + crypto:stream_encrypt(crypto:stream_init(Name, <<0:Len>>, <<0:128>>), <<"">>); + aes_gcm -> + {<<_/binary>>, <<_/binary>>} = + crypto:block_encrypt(Name, + _Key = <<0:Len>>, + _IV = <<0:12/unsigned-unit:8>>, + {<<"AAD">>,"PT"}) + end + of + _ -> true + catch + _:_ -> false + end. + + +same(Algs) -> [{client2server,Algs}, {server2client,Algs}]. + + +%% default_algorithms(kex) -> % Example of how to disable an algorithm +%% supported_algorithms(kex, ['ecdh-sha2-nistp521']); + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% +%% Other utils +%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% trim_tail(Str) -> lists:reverse(trim_head(lists:reverse(Str))). |