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-rw-r--r--lib/ssh/src/ssh_connection_handler.erl15
-rw-r--r--lib/ssh/src/ssh_transport.erl177
2 files changed, 149 insertions, 43 deletions
diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl
index 8e4831a601..4b41c10cbb 100644
--- a/lib/ssh/src/ssh_connection_handler.erl
+++ b/lib/ssh/src/ssh_connection_handler.erl
@@ -356,6 +356,8 @@ alg(ConnectionHandler) ->
| undefined,
encrypted_data_buffer = <<>> :: binary()
| undefined,
+ aead_data = <<>> :: binary()
+ | undefined,
undecrypted_packet_length :: undefined | non_neg_integer(),
key_exchange_init_msg :: #ssh_msg_kexinit{}
| undefined,
@@ -1308,14 +1310,16 @@ handle_event(info, {Proto, Sock, NewData}, StateName, D0 = #data{socket = Sock,
try ssh_transport:handle_packet_part(
D0#data.decrypted_data_buffer,
<<(D0#data.encrypted_data_buffer)/binary, NewData/binary>>,
- D0#data.undecrypted_packet_length,
+ D0#data.aead_data,
+ D0#data.undecrypted_packet_length,
D0#data.ssh_params)
of
{packet_decrypted, DecryptedBytes, EncryptedDataRest, Ssh1} ->
D1 = D0#data{ssh_params =
Ssh1#ssh{recv_sequence = ssh_transport:next_seqnum(Ssh1#ssh.recv_sequence)},
decrypted_data_buffer = <<>>,
- undecrypted_packet_length = undefined,
+ undecrypted_packet_length = undefined,
+ aead_data = <<>>,
encrypted_data_buffer = EncryptedDataRest},
try
ssh_message:decode(set_kex_overload_prefix(DecryptedBytes,D1))
@@ -1353,14 +1357,15 @@ handle_event(info, {Proto, Sock, NewData}, StateName, D0 = #data{socket = Sock,
StateName, D1),
{stop, Shutdown, D}
end;
-
- {get_more, DecryptedBytes, EncryptedDataRest, RemainingSshPacketLen, Ssh1} ->
+
+ {get_more, DecryptedBytes, EncryptedDataRest, AeadData, RemainingSshPacketLen, Ssh1} ->
%% Here we know that there are not enough bytes in
%% EncryptedDataRest to use. We must wait for more.
inet:setopts(Sock, [{active, once}]),
{keep_state, D0#data{encrypted_data_buffer = EncryptedDataRest,
decrypted_data_buffer = DecryptedBytes,
- undecrypted_packet_length = RemainingSshPacketLen,
+ undecrypted_packet_length = RemainingSshPacketLen,
+ aead_data = AeadData,
ssh_params = Ssh1}};
{bad_mac, Ssh1} ->
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index b6d7aa0b1b..d6b9142529 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -36,7 +36,7 @@
default_algorithms/0, default_algorithms/1,
algo_classes/0, algo_class/1,
algo_two_spec_classes/0, algo_two_spec_class/1,
- handle_packet_part/4,
+ handle_packet_part/5,
handle_hello_version/1,
key_exchange_init_msg/1,
key_init/3, new_keys_message/1,
@@ -114,7 +114,8 @@ default_algorithms(kex) ->
default_algorithms(cipher) ->
supported_algorithms(cipher, same(['AEAD_AES_128_GCM',
- 'AEAD_AES_256_GCM']));
+ 'AEAD_AES_256_GCM'
+ ]));
default_algorithms(mac) ->
supported_algorithms(mac, same(['AEAD_AES_128_GCM',
'AEAD_AES_256_GCM']));
@@ -160,6 +161,7 @@ supported_algorithms(cipher) ->
same(
select_crypto_supported(
[
+ {'[email protected]', [{ciphers,chacha20}, {macs,poly1305}]},
{'[email protected]', [{ciphers,{aes_gcm,256}}]},
{'aes256-ctr', [{ciphers,{aes_ctr,256}}]},
{'aes192-ctr', [{ciphers,{aes_ctr,192}}]},
@@ -982,13 +984,14 @@ select_algorithm(Role, Client, Server, Opts) ->
%%% 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}.
+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'=C, _) -> {C, C};
+aead_gcm_simultan('AEAD_AES_256_GCM'=C, _) -> {C, C};
+aead_gcm_simultan(_, 'AEAD_AES_128_GCM'=C) -> {C, C};
+aead_gcm_simultan(_, 'AEAD_AES_256_GCM'=C) -> {C, C};
+aead_gcm_simultan('[email protected]'=C, _)-> {C, C};
+aead_gcm_simultan(Cipher, Mac) -> {Cipher,Mac}.
select_encrypt_decrypt(client, Client, Server) ->
@@ -1136,7 +1139,7 @@ pack(PlainText,
encrypt = CryptoAlg} = Ssh0, PacketLenDeviationForTests) when is_binary(PlainText) ->
{Ssh1, CompressedPlainText} = compress(Ssh0, PlainText),
- {EcryptedPacket, MAC, Ssh3} =
+ {FinalPacket, Ssh3} =
case pkt_type(CryptoAlg) of
common ->
PaddingLen = padding_length(4+1+size(CompressedPlainText), Ssh0),
@@ -1145,16 +1148,15 @@ pack(PlainText,
PlainPacketData = <<?UINT32(PlainPacketLen),?BYTE(PaddingLen), CompressedPlainText/binary, Padding/binary>>,
{Ssh2, EcryptedPacket0} = encrypt(Ssh1, PlainPacketData),
MAC0 = mac(MacAlg, MacKey, SeqNum, PlainPacketData),
- {EcryptedPacket0, MAC0, Ssh2};
+ {<<EcryptedPacket0/binary,MAC0/binary>>, 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}
+ {Ssh2, {EcryptedPacket0,MAC0}} = encrypt(Ssh1, <<?UINT32(PlainPacketLen),PlainPacketData/binary>>),
+ {<<EcryptedPacket0/binary,MAC0/binary>>, Ssh2}
end,
- FinalPacket = [EcryptedPacket, MAC],
Ssh = Ssh3#ssh{send_sequence = (SeqNum+1) band 16#ffffffff},
{FinalPacket, Ssh}.
@@ -1174,31 +1176,31 @@ padding_length(Size, #ssh{encrypt_block_size = BlockSize,
-handle_packet_part(<<>>, Encrypted0, undefined, #ssh{decrypt = CryptoAlg} = Ssh0) ->
+handle_packet_part(<<>>, Encrypted0, AEAD0, 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};
+ {get_more, <<>>, Encrypted0, AEAD0, undefined, Ssh0};
- {ok, PacketLen, _, _, _} when PacketLen > ?SSH_MAX_PACKET_SIZE ->
+ {ok, PacketLen, _, _, _, _} when PacketLen > ?SSH_MAX_PACKET_SIZE ->
%% far too long message than expected
{error, {exceeds_max_size,PacketLen}};
- {ok, PacketLen, Decrypted, Encrypted1,
+ {ok, PacketLen, Decrypted, Encrypted1, AEAD,
#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)
+ handle_packet_part(Decrypted, Encrypted1, AEAD, TotalNeeded, Ssh1)
end;
-handle_packet_part(DecryptedPfx, EncryptedBuffer, TotalNeeded, Ssh0)
+handle_packet_part(DecryptedPfx, EncryptedBuffer, AEAD, TotalNeeded, Ssh0)
when (size(DecryptedPfx)+size(EncryptedBuffer)) < TotalNeeded ->
%% need more bytes to finalize the packet
- {get_more, DecryptedPfx, EncryptedBuffer, TotalNeeded, Ssh0};
+ {get_more, DecryptedPfx, EncryptedBuffer, AEAD, TotalNeeded, Ssh0};
-handle_packet_part(DecryptedPfx, EncryptedBuffer, TotalNeeded,
+handle_packet_part(DecryptedPfx, EncryptedBuffer, AEAD, TotalNeeded,
#ssh{recv_mac_size = MacSize,
decrypt = CryptoAlg} = Ssh0) ->
%% enough bytes to decode the packet.
@@ -1216,8 +1218,7 @@ handle_packet_part(DecryptedPfx, EncryptedBuffer, TotalNeeded,
{packet_decrypted, DecompressedPayload, NextPacketBytes, Ssh}
end;
aead ->
- PacketLenBin = DecryptedPfx,
- case decrypt(Ssh0, {PacketLenBin,EncryptedSfx,Mac}) of
+ case decrypt(Ssh0, {AEAD,EncryptedSfx,Mac}) of
{Ssh1, error} ->
{bad_mac, Ssh1};
{Ssh1, DecryptedSfx} ->
@@ -1234,21 +1235,29 @@ get_length(common, EncryptedBuffer, #ssh{decrypt_block_size = BlockSize} = Ssh0)
<<EncBlock:BlockSize/binary, EncryptedRest/binary>> = EncryptedBuffer,
{Ssh,
<<?UINT32(PacketLen),_/binary>> = Decrypted} = decrypt(Ssh0, EncBlock),
- {ok, PacketLen, Decrypted, EncryptedRest, Ssh};
+ {ok, PacketLen, Decrypted, EncryptedRest, <<>>, Ssh};
false ->
get_more
end;
+
get_length(aead, EncryptedBuffer, Ssh) ->
- case size(EncryptedBuffer) >= 4 of
- true ->
+ case {size(EncryptedBuffer) >= 4, Ssh#ssh.decrypt} of
+ {true, '[email protected]'} ->
+ <<EncryptedLen:4/binary, EncryptedRest/binary>> = EncryptedBuffer,
+ {Ssh1, PacketLenBin} = decrypt(Ssh, {length,EncryptedLen}),
+ <<?UINT32(PacketLen)>> = PacketLenBin,
+ {ok, PacketLen, PacketLenBin, EncryptedRest, EncryptedLen, Ssh1};
+ {true, _} ->
<<?UINT32(PacketLen), EncryptedRest/binary>> = EncryptedBuffer,
- {ok, PacketLen, <<?UINT32(PacketLen)>>, EncryptedRest, Ssh};
- false ->
+ {ok, PacketLen, <<?UINT32(PacketLen)>>, EncryptedRest, <<?UINT32(PacketLen)>>, Ssh};
+ {false, _} ->
get_more
end.
+
pkt_type('AEAD_AES_128_GCM') -> aead;
pkt_type('AEAD_AES_256_GCM') -> aead;
+pkt_type('[email protected]') -> aead;
pkt_type(_) -> common.
payload(<<PacketLen:32, PaddingLen:8, PayloadAndPadding/binary>>) ->
@@ -1353,11 +1362,32 @@ cipher('aes192-ctr') ->
cipher('aes256-ctr') ->
#cipher_data{key_bytes = 32,
iv_bytes = 16,
- block_bytes = 16}.
+ block_bytes = 16};
+
+cipher('[email protected]') -> % FIXME: Verify!!
+ #cipher_data{key_bytes = 32,
+ iv_bytes = 12,
+ block_bytes = 8}.
+
encrypt_init(#ssh{encrypt = none} = Ssh) ->
{ok, Ssh};
+encrypt_init(#ssh{encrypt = '[email protected]', role = client} = Ssh) ->
+ %% [email protected] uses two independent crypto streams, one (chacha20)
+ %% for the length used in stream mode, and the other (chacha20-poly1305) as AEAD for
+ %% the payload and to MAC the length||payload.
+ %% See draft-josefsson-ssh-chacha20-poly1305-openssh-00
+ <<K2:32/binary,K1:32/binary>> = hash(Ssh, "C", 512),
+ {ok, Ssh#ssh{encrypt_keys = {K1,K2}
+ % encrypt_block_size = 16, %default = 8. What to set it to? 64 (openssl chacha.h)
+ % ctx and iv is setup for each packet
+ }};
+encrypt_init(#ssh{encrypt = '[email protected]', role = server} = Ssh) ->
+ <<K2:32/binary,K1:32/binary>> = hash(Ssh, "D", 512),
+ {ok, Ssh#ssh{encrypt_keys = {K1,K2}
+ % encrypt_block_size = 16, %default = 8. What to set it to?
+ }};
encrypt_init(#ssh{encrypt = 'AEAD_AES_128_GCM', role = client} = Ssh) ->
IV = hash(Ssh, "A", 12*8),
<<K:16/binary>> = hash(Ssh, "C", 128),
@@ -1458,18 +1488,40 @@ encrypt_final(Ssh) ->
encrypt(#ssh{encrypt = none} = Ssh, Data) ->
{Ssh, Data};
+encrypt(#ssh{encrypt = '[email protected]',
+ encrypt_keys = {K1,K2},
+ send_sequence = Seq} = Ssh,
+ <<LenData:4/binary, PayloadData/binary>>) ->
+ %% Encrypt length
+ IV1 = <<0:8/unit:8, Seq:8/unit:8>>,
+ {_,EncLen} = crypto:stream_encrypt(crypto:stream_init(chacha20, K1, IV1),
+ LenData),
+ %% Encrypt payload
+ IV2 = <<1:8/little-unit:8, Seq:8/unit:8>>,
+ {_,EncPayloadData} = crypto:stream_encrypt(crypto:stream_init(chacha20, K2, IV2),
+ PayloadData),
+
+ %% MAC tag
+ {_,PolyKey} = crypto:stream_encrypt(crypto:stream_init(chacha20, K2, <<0:8/unit:8,Seq:8/unit:8>>),
+ <<0:32/unit:8>>),
+ EncBytes = <<EncLen/binary,EncPayloadData/binary>>,
+ Ctag = crypto:poly1305(PolyKey, EncBytes),
+ %% Result
+ {Ssh, {EncBytes,Ctag}};
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),
+ encrypt_ctx = IV0} = Ssh,
+ <<LenData:4/binary, PayloadData/binary>>) ->
+ {Ctext,Ctag} = crypto:block_encrypt(aes_gcm, K, IV0, {LenData,PayloadData}),
IV = next_gcm_iv(IV0),
- {Ssh#ssh{encrypt_ctx = IV}, Enc};
+ {Ssh#ssh{encrypt_ctx = IV}, {<<LenData/binary,Ctext/binary>>,Ctag}};
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),
+ encrypt_ctx = IV0} = Ssh,
+ <<LenData:4/binary, PayloadData/binary>>) ->
+ {Ctext,Ctag} = crypto:block_encrypt(aes_gcm, K, IV0, {LenData,PayloadData}),
IV = next_gcm_iv(IV0),
- {Ssh#ssh{encrypt_ctx = IV}, Enc};
+ {Ssh#ssh{encrypt_ctx = IV}, {<<LenData/binary,Ctext/binary>>,Ctag}};
encrypt(#ssh{encrypt = '3des-cbc',
encrypt_keys = {K1,K2,K3},
encrypt_ctx = IV0} = Ssh, Data) ->
@@ -1502,6 +1554,14 @@ encrypt(#ssh{encrypt = 'aes256-ctr',
decrypt_init(#ssh{decrypt = none} = Ssh) ->
{ok, Ssh};
+decrypt_init(#ssh{decrypt = '[email protected]', role = client} = Ssh) ->
+ <<K2:32/binary,K1:32/binary>> = hash(Ssh, "D", 512),
+ {ok, Ssh#ssh{decrypt_keys = {K1,K2}
+ }};
+decrypt_init(#ssh{decrypt = '[email protected]', role = server} = Ssh) ->
+ <<K2:32/binary,K1:32/binary>> = hash(Ssh, "C", 512),
+ {ok, Ssh#ssh{decrypt_keys = {K1,K2}
+ }};
decrypt_init(#ssh{decrypt = 'AEAD_AES_128_GCM', role = client} = Ssh) ->
IV = hash(Ssh, "B", 12*8),
<<K:16/binary>> = hash(Ssh, "D", 128),
@@ -1602,6 +1662,31 @@ decrypt_final(Ssh) ->
decrypt(Ssh, <<>>) ->
{Ssh, <<>>};
+decrypt(#ssh{decrypt = '[email protected]',
+ decrypt_keys = {K1,_K2},
+ recv_sequence = Seq} = Ssh, {length,EncryptedLen}) ->
+ {_State,PacketLenBin} =
+ crypto:stream_decrypt(crypto:stream_init(chacha20, K1, <<0:8/unit:8, Seq:8/unit:8>>),
+ EncryptedLen),
+ {Ssh, PacketLenBin};
+decrypt(#ssh{decrypt = '[email protected]',
+ decrypt_keys = {_K1,K2},
+ recv_sequence = Seq} = Ssh, {AAD,Ctext,Ctag}) ->
+ %% The length is already decoded and used to divide the input
+ %% Check the mac (important that it is timing-safe):
+ {_,PolyKey} =
+ crypto:stream_encrypt(crypto:stream_init(chacha20, K2, <<0:8/unit:8,Seq:8/unit:8>>),
+ <<0:32/unit:8>>),
+ case equal_const_time(Ctag, crypto:poly1305(PolyKey, <<AAD/binary,Ctext/binary>>)) of
+ true ->
+ %% MAC is ok, decode
+ IV2 = <<1:8/little-unit:8, Seq:8/unit:8>>,
+ {_,PlainText} =
+ crypto:stream_decrypt(crypto:stream_init(chacha20,K2,IV2), Ctext),
+ {Ssh, PlainText};
+ false ->
+ {Ssh,error}
+ end;
decrypt(#ssh{decrypt = none} = Ssh, Data) ->
{Ssh, Data};
decrypt(#ssh{decrypt = 'AEAD_AES_128_GCM',
@@ -1744,7 +1829,7 @@ send_mac_init(SSH) ->
Key = hash(SSH, "F", KeySize),
{ok, SSH#ssh { send_mac_key = Key }}
end;
- aead ->
+ _ ->
%% Not applicable
{ok, SSH}
end.
@@ -1765,7 +1850,7 @@ recv_mac_init(SSH) ->
Key = hash(SSH, "E", 8*mac_key_bytes(SSH#ssh.recv_mac)),
{ok, SSH#ssh { recv_mac_key = Key }}
end;
- aead ->
+ _ ->
%% Not applicable
{ok, SSH}
end.
@@ -1905,6 +1990,7 @@ mac_key_bytes('hmac-sha2-256')-> 32;
mac_key_bytes('hmac-sha2-512')-> 64;
mac_key_bytes('AEAD_AES_128_GCM') -> 0;
mac_key_bytes('AEAD_AES_256_GCM') -> 0;
+mac_key_bytes('[email protected]') -> 0;
mac_key_bytes(none) -> 0.
mac_digest_size('hmac-sha1') -> 20;
@@ -1915,6 +2001,7 @@ 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('[email protected]') -> 16;
mac_digest_size(none) -> 0.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -2026,6 +2113,20 @@ same(Algs) -> [{client2server,Algs}, {server2client,Algs}].
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%% Compare two binaries in a timing safe maner.
+%%% The time spent in comparing should not be different depending on where in the binaries they differ.
+%%% This is to avoid a certain side-channel attac.
+equal_const_time(X1, X2) -> equal_const_time(X1, X2, true).
+
+equal_const_time(<<B1,R1/binary>>, <<B2,R2/binary>>, Truth) ->
+ equal_const_time(R1, R2, Truth and (B1 == B2));
+equal_const_time(<<>>, <<>>, Truth) ->
+ Truth;
+equal_const_time(_, _, _) ->
+ false.
+
+%%%-------- Remove CR, LF and following characters from a line
+
trim_tail(Str) ->
lists:takewhile(fun(C) ->
C=/=$\r andalso C=/=$\n
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 15:27:46 +0000