diff options
Diffstat (limited to 'lib/ssh/src/ssh_transport.erl')
-rw-r--r-- | lib/ssh/src/ssh_transport.erl | 251 |
1 files changed, 133 insertions, 118 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 90a94a7e86..631c4d0213 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -51,10 +51,12 @@ extract_public_key/1, ssh_packet/2, pack/2, valid_key_sha_alg/2, - sha/1, sign/3, verify/4]). + sha/1, sign/3, verify/5]). + +-export([dbg_trace/3]). %%% For test suites --export([pack/3]). +-export([pack/3, adjust_algs_for_peer_version/2]). -export([decompress/2, decrypt_blocks/3, is_valid_mac/3 ]). % FIXME: remove -define(Estring(X), ?STRING((if is_binary(X) -> X; @@ -319,10 +321,11 @@ handle_kexinit_msg(#ssh_msg_kexinit{} = CounterPart, #ssh_msg_kexinit{} = Own, key_exchange_first_msg(Algos#alg.kex, Ssh#ssh{algorithms = Algos}) catch - _:_ -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Selection of key exchange algorithm failed"}) + Class:Error -> + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Kexinit failed in client: ~p:~p", + [Class,Error]) + ) end; handle_kexinit_msg(#ssh_msg_kexinit{} = CounterPart, #ssh_msg_kexinit{} = Own, @@ -335,10 +338,11 @@ handle_kexinit_msg(#ssh_msg_kexinit{} = CounterPart, #ssh_msg_kexinit{} = Own, Algos -> {ok, Ssh#ssh{algorithms = Algos}} catch - _:_ -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Selection of key exchange algorithm failed"}) + Class:Error -> + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Kexinit failed in server: ~p:~p", + [Class,Error]) + ) end. @@ -439,12 +443,10 @@ handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, session_id = sid(Ssh1, H)}}; true -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed, 'e' out of bounds"}, - {error,bad_e_from_peer} - ) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Kexdh init failed, received 'e' out of bounds~n E=~p~n P=~p", + [E,P]) + ) end. handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = PeerPubHostKey, @@ -464,20 +466,16 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = PeerPubHostKey, exchanged_hash = H, session_id = sid(Ssh, H)})}; Error -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed"}, - Error) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Kexdh init failed. Verify host key: ~p",[Error]) + ) end; true -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed, 'f' out of bounds"}, - bad_f_from_peer - ) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Kexdh init failed, received 'f' out of bounds~n F=~p~n P=~p", + [F,P]) + ) end. @@ -501,11 +499,9 @@ handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = Min0, keyex_info = {Min0, Max0, NBits} }}; {error,_} -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_PROTOCOL_ERROR, - description = "No possible diffie-hellman-group-exchange group found" - }) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("No possible diffie-hellman-group-exchange group found",[]) + ) end; handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request_old{n = NBits}, @@ -535,20 +531,14 @@ handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request_old{n = NBits}, keyex_info = {-1, -1, NBits} % flag for kex_hash calc }}; {error,_} -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_PROTOCOL_ERROR, - description = "No possible diffie-hellman-group-exchange group found" - }) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("No possible diffie-hellman-group-exchange group found",[]) + ) end; handle_kex_dh_gex_request(_, _) -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed, bad values in ssh_msg_kex_dh_gex_request"}, - bad_ssh_msg_kex_dh_gex_request). - + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + "Key exchange failed, bad values in ssh_msg_kex_dh_gex_request"). adjust_gex_min_max(Min0, Max0, Opts) -> {Min1, Max1} = ?GET_OPT(dh_gex_limits, Opts), @@ -558,11 +548,8 @@ adjust_gex_min_max(Min0, Max0, Opts) -> Min2 =< Max2 -> {Min2, Max2}; Max2 < Min2 -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_PROTOCOL_ERROR, - description = "No possible diffie-hellman-group-exchange group possible" - }) + ?DISCONNECT(?SSH_DISCONNECT_PROTOCOL_ERROR, + "No possible diffie-hellman-group-exchange group possible") end. @@ -600,18 +587,15 @@ handle_kex_dh_gex_init(#ssh_msg_kex_dh_gex_init{e = E}, session_id = sid(Ssh, H) }}; true -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed, 'K' out of bounds"}, - bad_K) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + "Kexdh init failed, received 'k' out of bounds" + ) end; true -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed, 'e' out of bounds"}, - bad_e_from_peer) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Kexdh gex init failed, received 'e' out of bounds~n E=~p~n P=~p", + [E,P]) + ) end. handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = PeerPubHostKey, @@ -634,28 +618,22 @@ handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = PeerPubHostK {ok, SshPacket, install_alg(snd, Ssh#ssh{shared_secret = ssh_bits:mpint(K), exchanged_hash = H, session_id = sid(Ssh, H)})}; - _Error -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed" - }) + Error -> + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Kexdh gex reply failed. Verify host key: ~p",[Error]) + ) end; true -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed, 'K' out of bounds"}, - bad_K) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + "Kexdh gex init failed, 'K' out of bounds" + ) end; true -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed, 'f' out of bounds"}, - bad_f_from_peer - ) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Kexdh gex init failed, received 'f' out of bounds~n F=~p~n P=~p", + [F,P]) + ) end. %%%---------------------------------------------------------------- @@ -686,12 +664,11 @@ handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, exchanged_hash = H, session_id = sid(Ssh1, H)}} catch - _:_ -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Peer ECDH public key is invalid"}, - invalid_peer_public_key) + Class:Error -> + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("ECDH compute key failed in server: ~p:~p", + [Class,Error]) + ) end. handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey, @@ -713,19 +690,16 @@ handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey, exchanged_hash = H, session_id = sid(Ssh, H)})}; Error -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Key exchange failed"}, - Error) + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("ECDH reply failed. Verify host key: ~p",[Error]) + ) end catch - _:_ -> - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, - description = "Peer ECDH public key is invalid"}, - invalid_peer_public_key) + Class:Error -> + ?DISCONNECT(?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + io_lib:format("Peer ECDH public key seem invalid: ~p:~p", + [Class,Error]) + ) end. @@ -735,11 +709,11 @@ handle_new_keys(#ssh_msg_newkeys{}, Ssh0) -> #ssh{} = Ssh -> {ok, Ssh} catch - _C:_Error -> %% TODO: Throw earlier .... - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, - description = "Install alg failed" - }) + Class:Error -> %% TODO: Throw earlier ... + ?DISCONNECT(?SSH_DISCONNECT_PROTOCOL_ERROR, + io_lib:format("Install alg failed: ~p:~p", + [Class,Error]) + ) end. @@ -825,7 +799,7 @@ extract_public_key(#{engine:=_, key_id:=_, algorithm:=Alg} = M) -> verify_host_key(#ssh{algorithms=Alg}=SSH, PublicKey, Digest, {AlgStr,Signature}) -> case atom_to_list(Alg#alg.hkey) of AlgStr -> - case verify(Digest, sha(Alg#alg.hkey), Signature, PublicKey) of + case verify(Digest, sha(Alg#alg.hkey), Signature, PublicKey, SSH) of false -> {error, bad_signature}; true -> @@ -889,10 +863,13 @@ known_host_key(#ssh{opts = Opts, key_cb = {KeyCb,KeyCbOpts}, peer = {PeerName,_} {_,true} -> ok; {_,false} -> + DoAdd = ?GET_OPT(save_accepted_host, Opts), case accepted_host(Ssh, PeerName, Public, Opts) of - true -> + true when DoAdd == true -> {_,R} = add_host_key(KeyCb, PeerName, Public, [{key_cb_private,KeyCbOpts}|UserOpts]), R; + true when DoAdd == false -> + ok; false -> {error, rejected_by_user}; {error,E} -> @@ -1054,9 +1031,7 @@ install_alg(Dir, SSH) -> alg_setup(snd, SSH) -> ALG = SSH#ssh.algorithms, - SSH#ssh{kex = ALG#alg.kex, - hkey = ALG#alg.hkey, - encrypt = ALG#alg.encrypt, + SSH#ssh{encrypt = ALG#alg.encrypt, send_mac = ALG#alg.send_mac, send_mac_size = mac_digest_size(ALG#alg.send_mac), compress = ALG#alg.compress, @@ -1068,9 +1043,7 @@ alg_setup(snd, SSH) -> alg_setup(rcv, SSH) -> ALG = SSH#ssh.algorithms, - SSH#ssh{kex = ALG#alg.kex, - hkey = ALG#alg.hkey, - decrypt = ALG#alg.decrypt, + SSH#ssh{decrypt = ALG#alg.decrypt, recv_mac = ALG#alg.recv_mac, recv_mac_size = mac_digest_size(ALG#alg.recv_mac), decompress = ALG#alg.decompress, @@ -1112,10 +1085,9 @@ select_all(CL, SL) when length(CL) + length(SL) < ?MAX_NUM_ALGORITHMS -> %% algorithms used by client and server (client pref) 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,")."]), - ssh_connection_handler:disconnect( - #ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, - description = Err}). + Error = lists:concat(["Received too many algorithms (",length(CL),"+",length(SL)," >= ",?MAX_NUM_ALGORITHMS,")."]), + ?DISCONNECT(?SSH_DISCONNECT_PROTOCOL_ERROR, + Error). select([], []) -> @@ -1288,7 +1260,7 @@ mk_dss_sig(DerSignature) -> <<R:160/big-unsigned-integer, S:160/big-unsigned-integer>>. -verify(PlainText, HashAlg, Sig, {_, #'Dss-Parms'{}} = Key) -> +verify(PlainText, HashAlg, Sig, {_, #'Dss-Parms'{}} = Key, _) -> case Sig of <<R:160/big-unsigned-integer, S:160/big-unsigned-integer>> -> Signature = public_key:der_encode('Dss-Sig-Value', #'Dss-Sig-Value'{r = R, s = S}), @@ -1296,7 +1268,7 @@ verify(PlainText, HashAlg, Sig, {_, #'Dss-Parms'{}} = Key) -> _ -> false end; -verify(PlainText, HashAlg, Sig, {#'ECPoint'{},_} = Key) -> +verify(PlainText, HashAlg, Sig, {#'ECPoint'{},_} = Key, _) -> case Sig of <<?UINT32(Rlen),R:Rlen/big-signed-integer-unit:8, ?UINT32(Slen),S:Slen/big-signed-integer-unit:8>> -> @@ -1306,7 +1278,15 @@ verify(PlainText, HashAlg, Sig, {#'ECPoint'{},_} = Key) -> _ -> false end; -verify(PlainText, HashAlg, Sig, Key) -> + +verify(PlainText, HashAlg, Sig, #'RSAPublicKey'{}=Key, #ssh{role = server, + c_version = "SSH-2.0-OpenSSH_7."++_}) + when HashAlg == sha256; HashAlg == sha512 -> + %% Public key signing bug in in OpenSSH >= 7.2 + public_key:verify(PlainText, HashAlg, Sig, Key) + orelse public_key:verify(PlainText, sha, Sig, Key); + +verify(PlainText, HashAlg, Sig, Key, _) -> public_key:verify(PlainText, HashAlg, Sig, Key). @@ -1799,7 +1779,7 @@ mac('hmac-sha2-512', Key, SeqNum, Data) -> hash(_SSH, _Char, 0) -> <<>>; hash(SSH, Char, N) -> - HashAlg = sha(SSH#ssh.kex), + HashAlg = sha(SSH#ssh.algorithms#alg.kex), K = SSH#ssh.shared_secret, H = SSH#ssh.exchanged_hash, K1 = crypto:hash(HashAlg, [K, H, Char, SSH#ssh.session_id]), @@ -1828,9 +1808,10 @@ kex_alg_dependent({E, F, K}) -> %% diffie-hellman and ec diffie-hellman (with E = Q_c, F = Q_s) <<?Empint(E), ?Empint(F), ?Empint(K)>>; -kex_alg_dependent({-1, _, -1, _, _, E, F, K}) -> +kex_alg_dependent({-1, NBits, -1, Prime, Gen, E, F, K}) -> %% ssh_msg_kex_dh_gex_request_old - <<?Empint(E), ?Empint(F), ?Empint(K)>>; + <<?Euint32(NBits), + ?Empint(Prime), ?Empint(Gen), ?Empint(E), ?Empint(F), ?Empint(K)>>; kex_alg_dependent({Min, NBits, Max, Prime, Gen, E, F, K}) -> %% diffie-hellman group exchange @@ -1869,9 +1850,6 @@ public_algo({#'ECPoint'{},{namedCurve,OID}}) -> Curve = public_key:oid2ssh_curvename(OID), list_to_atom("ecdsa-sha2-" ++ binary_to_list(Curve)). - - - sha('ssh-rsa') -> sha; sha('rsa-sha2-256') -> sha256; sha('rsa-sha2-384') -> sha384; @@ -2030,3 +2008,40 @@ trim_tail(Str) -> lists:takewhile(fun(C) -> C=/=$\r andalso C=/=$\n end, Str). + +%%%################################################################ +%%%# +%%%# Tracing +%%%# + +dbg_trace(points, _, _) -> [alg, ssh_messages, raw_messages, hello]; + +dbg_trace(flags, hello, _) -> [c]; +dbg_trace(on, hello, _) -> dbg:tp(?MODULE,hello_version_msg,1,x), + dbg:tp(?MODULE,handle_hello_version,1,x); +dbg_trace(off, hello, _) -> dbg:ctpg(?MODULE,hello_version_msg,1), + dbg:ctpg(?MODULE,handle_hello_version,1); + +dbg_trace(C, raw_messages, A) -> dbg_trace(C, hello, A); +dbg_trace(C, ssh_messages, A) -> dbg_trace(C, hello, A); + +dbg_trace(flags, alg, _) -> [c]; +dbg_trace(on, alg, _) -> dbg:tpl(?MODULE,select_algorithm,4,x); +dbg_trace(off, alg, _) -> dbg:ctpl(?MODULE,select_algorithm,4); + + +dbg_trace(format, hello, {return_from,{?MODULE,hello_version_msg,1},Hello}) -> + ["Going to send hello message:\n", + Hello + ]; +dbg_trace(format, hello, {call,{?MODULE,handle_hello_version,[Hello]}}) -> + ["Received hello message:\n", + Hello + ]; + +dbg_trace(format, alg, {return_from,{?MODULE,select_algorithm,4},{ok,Alg}}) -> + ["Negotiated algorithms:\n", + wr_record(Alg) + ]. + +?wr_record(alg). |