diff options
| -rw-r--r-- | lib/ssh/src/ssh.hrl | 1 | ||||
| -rw-r--r-- | lib/ssh/src/ssh_transport.erl | 464 |
2 files changed, 333 insertions, 132 deletions
diff --git a/lib/ssh/src/ssh.hrl b/lib/ssh/src/ssh.hrl index 4ad936f742..8efc743b67 100644 --- a/lib/ssh/src/ssh.hrl +++ b/lib/ssh/src/ssh.hrl @@ -29,7 +29,6 @@ -define(SSH_DEFAULT_PORT, 22). -define(SSH_MAX_PACKET_SIZE, (256*1024)). --define(SSH_LENGHT_INDICATOR_SIZE, 4). -define(REKEY_TIMOUT, 3600000). -define(REKEY_DATA_TIMOUT, 60000). -define(DEFAULT_PROFILE, default). diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index f18e4b4d01..e2d19b9cef 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -70,10 +70,15 @@ default_algorithms() -> [{K,default_algorithms(K)} || K <- algo_classes()]. algo_classes() -> [kex, public_key, cipher, mac, compression]. -%% default_algorithms(kex) -> % Example of how to disable an algorithm -%% supported_algorithms(kex, ['ecdh-sha2-nistp521']); + +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(Alg, []). supported_algorithms() -> [{K,supported_algorithms(K)} || K <- algo_classes()]. @@ -101,19 +106,25 @@ supported_algorithms(public_key) -> 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}]}, - {'3des-cbc', [{ciphers,des3_cbc}]} + [{'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}]} + [{'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) -> @@ -122,46 +133,6 @@ supported_algorithms(compression) -> 'zlib' ]). -%% Dialyzer complains when not called...supported_algorithms(Key, [{client2server,BL1},{server2client,BL2}]) -> -%% Dialyzer complains when not called... [{client2server,As1},{server2client,As2}] = supported_algorithms(Key), -%% Dialyzer complains when not called... [{client2server,As1--BL1},{server2client,As2--BL2}]; -%% Dialyzer complains when not called...supported_algorithms(Key, BlackList) -> -%% Dialyzer complains when not called... 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=aes_ctr,Len}}) when is_integer(Len) -> - crypto_name_supported(Tag,Name,Supported) andalso - ctr_len_supported(Name,Len) - end, Conditions). - -crypto_name_supported(Tag, CryptoName, Supported) -> - lists:member(CryptoName, proplists:get_value(Tag,Supported,[])). - -ctr_len_supported(Name, Len) -> - try - crypto:stream_encrypt(crypto:stream_init(Name, <<0:Len>>, <<0:128>>), <<"">>) - of - {_,X} -> is_binary(X) - catch - _:_ -> false - end. - - -same(Algs) -> [{client2server,Algs}, {server2client,Algs}]. - - %%%---------------------------------------------------------------------------- versions(client, Options)-> Vsn = proplists:get_value(vsn, Options, ?DEFAULT_CLIENT_VERSION), @@ -755,8 +726,12 @@ 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), @@ -787,6 +762,38 @@ 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, @@ -821,18 +828,18 @@ 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), @@ -909,14 +916,39 @@ pack(Data, Ssh=#ssh{}) -> %%% 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(Data0, #ssh{encrypt_block_size = BlockSize, - send_sequence = SeqNum, send_mac = MacAlg, - send_mac_key = MacKey, - random_length_padding = RandomLengthPadding} - = Ssh0, - PacketLenDeviationForTests) when is_binary(Data0) -> - {Ssh1, Data} = compress(Ssh0, Data0), - PL = (BlockSize - ((4 + 1 + size(Data)) rem BlockSize)) rem BlockSize, +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, + 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, @@ -925,79 +957,94 @@ pack(Data0, #ssh{encrypt_block_size = BlockSize, ExtraPaddingLen = try crypto:rand_uniform(0,MaxExtraBlocks)*PadBlockSize catch _:_ -> 0 end, - PaddingLen = MinPaddingLen + ExtraPaddingLen, - Padding = ssh_bits:random(PaddingLen), - PacketLen = 1 + PaddingLen + size(Data) + PacketLenDeviationForTests, - 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}. - - -handle_packet_part(<<>>, Encoded0, undefined, Ssh0) -> + MinPaddingLen + ExtraPaddingLen. + + + +handle_packet_part(<<>>, Encrypted0, undefined, #ssh{decrypt = CryptoAlg} = Ssh0) -> %% New ssh packet - case get_length(Encoded0, Ssh0) of + case get_length(pkt_type(CryptoAlg), Encrypted0, Ssh0) of get_more -> %% too short to get the length - {get_more, <<>>, Encoded0, undefined, Ssh0}; + {get_more, <<>>, Encrypted0, undefined, Ssh0}; - {ok, PacketLen, _DecData, _Encoded1, _Ssh1} when PacketLen > ?SSH_MAX_PACKET_SIZE -> + {ok, PacketLen, _, _, _} when PacketLen > ?SSH_MAX_PACKET_SIZE -> %% far too long message than expected throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, description = "Bad packet length " ++ integer_to_list(PacketLen), language = ""}); - {ok, PacketLen, DecData, Encoded1, - #ssh{decrypt_block_size = BlockSize, - recv_mac_size = MacSize} = Ssh1} -> + {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 - Remaining = (PacketLen + ?SSH_LENGHT_INDICATOR_SIZE) - BlockSize + MacSize, - handle_packet_part(DecData, Encoded1, Remaining, Ssh1) + TotalNeeded = (4 + PacketLen + MacSize), + handle_packet_part(Decrypted, Encrypted1, TotalNeeded, Ssh1) end; -handle_packet_part(Decoded0, Encoded0, Remaining, Ssh0) - when size(Encoded0) < Remaining -> + +handle_packet_part(DecryptedPfx, EncryptedBuffer, TotalNeeded, Ssh0) + when (size(DecryptedPfx)+size(EncryptedBuffer)) < TotalNeeded -> %% need more bytes to finalize the packet - {get_more, Decoded0, Encoded0, Remaining, Ssh0}; -handle_packet_part(Decoded0, Encoded0, Remaining, - #ssh{recv_mac_size = MacSize} = Ssh0) -> + {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. - SshLengthNotDecoded = Remaining - MacSize, - <<PktT:SshLengthNotDecoded/binary, Mac:MacSize/binary, EncRest0/binary>> = Encoded0, - {Ssh1, DecData} = decrypt(Ssh0, PktT), - MsgBytes = <<Decoded0/binary,DecData/binary>>, - case is_valid_mac(Mac, MsgBytes, Ssh1) of - false -> - {bad_mac, Ssh1}; - true -> - {Ssh, DecompressedMsgBytes} = decompress(Ssh1, msg_data(MsgBytes)), - {decoded, DecompressedMsgBytes, EncRest0, Ssh} + 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(Encoded0, #ssh{decrypt_block_size = BlockSize} = Ssh0) -> - case size(Encoded0) >= erlang:max(8, BlockSize) of +get_length(common, EncryptedBuffer, #ssh{decrypt_block_size = BlockSize} = Ssh0) -> + case size(EncryptedBuffer) >= erlang:max(8, BlockSize) of true -> - <<EncBlock:BlockSize/binary, EncodedRest/binary>> = Encoded0, - {Ssh, Decoded} = decrypt(Ssh0, EncBlock), - <<?UINT32(PacketLen), _/binary>> = Decoded, - {ok, PacketLen, Decoded, EncodedRest, Ssh}; + <<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), @@ -1023,6 +1070,7 @@ verify(PlainText, Hash, Sig, {#'ECPoint'{},_} = Key) -> verify(PlainText, Hash, Sig, Key) -> public_key:verify(PlainText, Hash, Sig, Key). + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% Encryption @@ -1031,6 +1079,30 @@ verify(PlainText, Hash, Sig, Key) -> 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), @@ -1107,6 +1179,18 @@ 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) -> @@ -1139,6 +1223,30 @@ encrypt(#ssh{encrypt = 'aes256-ctr', 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)}, @@ -1217,6 +1325,18 @@ 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, @@ -1241,6 +1361,10 @@ decrypt(#ssh{decrypt = 'aes256-ctr', {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 %% @@ -1329,28 +1453,42 @@ decompress(#ssh{decompress = '[email protected]', decompress_ctx = Context, authe %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 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) -> @@ -1481,6 +1619,8 @@ 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, _}) -> @@ -1510,6 +1650,68 @@ 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 |