%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2005-2010. 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/.
%%
%% 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.
%%
%% %CopyrightEnd%
%%
%%
%%% Description: SSH file handling
-module(ssh_file).
-include("ssh.hrl").
-include("PKCS-1.hrl").
-include("DSS.hrl").
-include_lib("kernel/include/file.hrl").
-export([public_host_dsa_key/2,private_host_dsa_key/2,
public_host_rsa_key/2,private_host_rsa_key/2,
public_host_key/2,private_host_key/2,
lookup_host_key/3, add_host_key/3, % del_host_key/2,
lookup_user_key/3, ssh_dir/2, file_name/3]).
-export([private_identity_key/2,
public_identity_key/2]).
%% identity_keys/2]).
-export([encode_public_key/1, decode_public_key_v2/2]).
-import(lists, [reverse/1, append/1]).
-define(DBG_PATHS, true).
-define(PERM_700, 8#700).
-define(PERM_644, 8#644).
%% API
public_host_dsa_key(Type, Opts) ->
File = file_name(Type, "ssh_host_dsa_key.pub", Opts),
read_public_key_v2(File, "ssh-dss").
private_host_dsa_key(Type, Opts) ->
File = file_name(Type, "ssh_host_dsa_key", Opts),
read_private_key_v2(File, "ssh-dss").
public_host_rsa_key(Type, Opts) ->
File = file_name(Type, "ssh_host_rsa_key.pub", Opts),
read_public_key_v2(File, "ssh-rsa").
private_host_rsa_key(Type, Opts) ->
File = file_name(Type, "ssh_host_rsa_key", Opts),
read_private_key_v2(File, "ssh-rsa").
public_host_key(Type, Opts) ->
File = file_name(Type, "ssh_host_key", Opts),
case read_private_key_v1(File,public) of
{error, enoent} ->
read_public_key_v1(File++".pub");
Result ->
Result
end.
private_host_key(Type, Opts) ->
File = file_name(Type, "ssh_host_key", Opts),
read_private_key_v1(File,private).
%% in: "host" out: "host,1.2.3.4.
add_ip(Host) ->
case inet:getaddr(Host, inet) of
{ok, Addr} ->
case ssh_connection:encode_ip(Addr) of
false -> Host;
IPString -> Host ++ "," ++ IPString
end;
_ -> Host
end.
replace_localhost("localhost") ->
{ok, Hostname} = inet:gethostname(),
Hostname;
replace_localhost(Host) ->
Host.
%% lookup_host_key
%% return {ok, Key(s)} or {error, not_found}
%%
lookup_host_key(Host, Alg, Opts) ->
Host1 = replace_localhost(Host),
do_lookup_host_key(Host1, Alg, Opts).
do_lookup_host_key(Host, Alg, Opts) ->
case file:open(file_name(user, "known_hosts", Opts), [read]) of
{ok, Fd} ->
Res = lookup_host_key_fd(Fd, Host, Alg),
file:close(Fd),
Res;
{error, enoent} -> {error, not_found};
Error -> Error
end.
add_host_key(Host, Key, Opts) ->
Host1 = add_ip(replace_localhost(Host)),
KnownHosts = file_name(user, "known_hosts", Opts),
case file:open(KnownHosts, [write,append]) of
{ok, Fd} ->
ok = file:change_mode(KnownHosts, ?PERM_644),
Res = add_key_fd(Fd, Host1, Key),
file:close(Fd),
Res;
Error ->
Error
end.
%% del_host_key(Host, Opts) ->
%% Host1 = replace_localhost(Host),
%% case file:open(file_name(user, "known_hosts", Opts),[write,read]) of
%% {ok, Fd} ->
%% Res = del_key_fd(Fd, Host1),
%% file:close(Fd),
%% Res;
%% Error ->
%% Error
%% end.
identity_key_filename("ssh-dss") -> "id_dsa";
identity_key_filename("ssh-rsa") -> "id_rsa".
private_identity_key(Alg, Opts) ->
Path = file_name(user, identity_key_filename(Alg), Opts),
read_private_key_v2(Path, Alg).
public_identity_key(Alg, Opts) ->
Path = file_name(user, identity_key_filename(Alg) ++ ".pub", Opts),
read_public_key_v2(Path, Alg).
read_public_key_v2(File, Type) ->
case file:read_file(File) of
{ok,Bin} ->
List = binary_to_list(Bin),
case lists:prefix(Type, List) of
true ->
List1 = lists:nthtail(length(Type), List),
K_S = ssh_bits:b64_decode(List1),
decode_public_key_v2(K_S, Type);
false ->
{error, bad_format}
end;
Error ->
Error
end.
decode_public_key_v2(K_S, "ssh-rsa") ->
case ssh_bits:decode(K_S,[string,mpint,mpint]) of
["ssh-rsa", E, N] ->
{ok, #ssh_key { type = rsa,
public = {N,E},
comment=""}};
_ ->
{error, bad_format}
end;
decode_public_key_v2(K_S, "ssh-dss") ->
case ssh_bits:decode(K_S,[string,mpint,mpint,mpint,mpint]) of
["ssh-dss",P,Q,G,Y] ->
{ok,#ssh_key { type = dsa,
public = {P,Q,G,Y}
}};
_A ->
{error, bad_format}
end;
decode_public_key_v2(_, _) ->
{error, bad_format}.
read_public_key_v1(File) ->
case file:read_file(File) of
{ok,Bin} ->
List = binary_to_list(Bin),
case io_lib:fread("~d ~d ~d ~s", List) of
{ok,[_Sz,E,N,Comment],_} ->
{ok,#ssh_key { type = rsa,
public ={N,E},
comment = Comment }};
_Error ->
{error, bad_format}
end;
Error ->
Error
end.
%% pem_type("ssh-dss") -> "DSA";
%% pem_type("ssh-rsa") -> "RSA".
read_private_key_v2(File, Type) ->
case file:read_file(File) of
{ok, PemBin} ->
case catch (public_key:pem_decode(PemBin)) of
[{_, Bin, not_encrypted}] ->
decode_private_key_v2(Bin, Type);
Error -> %% Note we do not handle password encrypted keys at the moment
{error, Error}
end;
{error, Reason} ->
{error, Reason}
end.
%% case file:read_file(File) of
%% {ok,Bin} ->
%% case read_pem(binary_to_list(Bin), pem_type(Type)) of
%% {ok,Bin1} ->
%% decode_private_key_v2(Bin1, Type);
%% Error ->
%% Error
%% end;
%% Error ->
%% Error
%% end.
decode_private_key_v2(Private,"ssh-rsa") ->
case 'PKCS-1':decode( 'RSAPrivateKey', Private) of
{ok,RSA} -> %% FIXME Check for two-prime version
{ok, #ssh_key { type = rsa,
public = {RSA#'RSAPrivateKey'.modulus,
RSA#'RSAPrivateKey'.publicExponent},
private = {RSA#'RSAPrivateKey'.modulus,
RSA#'RSAPrivateKey'.privateExponent}
}};
Error ->
Error
end;
decode_private_key_v2(Private, "ssh-dss") ->
case 'DSS':decode('DSAPrivateKey', Private) of
{ok,DSA} -> %% FIXME Check for two-prime version
{ok, #ssh_key { type = dsa,
public = {DSA#'DSAPrivateKey'.p,
DSA#'DSAPrivateKey'.q,
DSA#'DSAPrivateKey'.g,
DSA#'DSAPrivateKey'.y},
private= {DSA#'DSAPrivateKey'.p,
DSA#'DSAPrivateKey'.q,
DSA#'DSAPrivateKey'.g,
DSA#'DSAPrivateKey'.x}
}};
_ ->
{error,bad_format}
end.
%% SSH1 private key format
%% <<"SSH PRIVATE KEY FILE FORMATE 1.1\n" 0:8
%% CipherNum:8, Reserved:32,
%% NSz/uint32, N/bignum, E/bignum, Comment/string,
%%
%% [ R0:8 R1:8 R0:8 R1:8, D/bignum, IQMP/bignum, Q/bignum, P/bignum, Pad(8)]>>
%%
%% where [ ] is encrypted using des3 (ssh1 version) and
%% a posssibly empty pass phrase using md5(passphase) as key
%%
read_private_key_v1(File, Type) ->
case file:read_file(File) of
{ok,<<"SSH PRIVATE KEY FILE FORMAT 1.1\n",0,
CipherNum,_Resereved:32,Bin/binary>>} ->
decode_private_key_v1(Bin, CipherNum,Type);
{ok,_} ->
{error, bad_format};
Error ->
Error
end.
decode_private_key_v1(Bin, CipherNum, Type) ->
case ssh_bits:decode(Bin,0,[uint32, bignum, bignum, string]) of
{Offset,[_NSz,N,E,Comment]} ->
if Type == public ->
{ok,#ssh_key { type=rsa,
public={N,E},
comment=Comment}};
Type == private ->
<<_:Offset/binary, Encrypted/binary>> = Bin,
case ssh_bits:decode(decrypt1(Encrypted, CipherNum),0,
[uint32, bignum, bignum,
bignum, bignum,{pad,8}]) of
{_,[_,D,IQMP,Q,P]} ->
{ok,#ssh_key { type=rsa,
public={N,E},
private={D,IQMP,Q,P},
comment=Comment}};
_ ->
{error,bad_format}
end
end;
_ ->
{error,bad_format}
end.
decrypt1(Bin, CipherNum) ->
decrypt1(Bin, CipherNum,"").
decrypt1(Bin, CipherNum, Phrase) ->
if CipherNum == ?SSH_CIPHER_NONE; Phrase == "" ->
Bin;
CipherNum == ?SSH_CIPHER_3DES ->
<<K1:8/binary, K2:8/binary>> = erlang:md5(Phrase),
K3 = K1,
IV = <<0,0,0,0,0,0,0,0>>,
Bin1 = crypto:des_cbc_decrypt(K3,IV,Bin),
Bin2 = crypto:des_cbc_encrypt(K2,IV,Bin1),
crypto:des_cbc_decrypt(K1,IV,Bin2)
end.
%% encrypt1(Bin, CipherNum) ->
%% encrypt1(Bin, CipherNum,"").
%% encrypt1(Bin, CipherNum, Phrase) ->
%% if CipherNum == ?SSH_CIPHER_NONE; Phrase == "" ->
%% Bin;
%% CipherNum == ?SSH_CIPHER_3DES ->
%% <<K1:8/binary, K2:8/binary>> = erlang:md5(Phrase),
%% K3 = K1,
%% IV = <<0,0,0,0,0,0,0,0>>,
%% Bin1 = crypto:des_cbc_encrypt(K1,IV,Bin),
%% Bin2 = crypto:des_cbc_decrypt(K2,IV,Bin1),
%% crypto:des_cbc_encrypt(K3,IV,Bin2)
%% end.
lookup_host_key_fd(Fd, Host, Alg) ->
case io:get_line(Fd, '') of
eof ->
{error, not_found};
Line ->
case string:tokens(Line, " ") of
[HostList, Alg, KeyData] ->
%% io:format(" ~p lookup_host_key_fd: HostList ~p Alg ~p KeyData ~p\n",
%% [Host, HostList, Alg, KeyData]),
case lists:member(Host, string:tokens(HostList, ",")) of
true ->
decode_public_key_v2(ssh_bits:b64_decode(KeyData), Alg);
false ->
lookup_host_key_fd(Fd, Host, Alg)
end;
_ ->
lookup_host_key_fd(Fd, Host, Alg)
end
end.
%% del_key_fd(Fd, Host) ->
%% del_key_fd(Fd, Host, 0, 0).
%% del_key_fd(Fd, Host, ReadPos0, WritePos0) ->
%% case io:get_line(Fd, '') of
%% eof ->
%% if ReadPos0 == WritePos0 ->
%% ok;
%% true ->
%% file:truncate(Fd)
%% end;
%% Line ->
%% {ok,ReadPos1} = file:position(Fd, cur),
%% case string:tokens(Line, " ") of
%% [HostList, _Type, _KeyData] ->
%% case lists:member(Host, string:tokens(HostList, ",")) of
%% true ->
%% del_key_fd(Fd, Host, ReadPos1, WritePos0);
%% false ->
%% if ReadPos0 == WritePos0 ->
%% del_key_fd(Fd, Host, ReadPos1, ReadPos1);
%% true ->
%% file:position(Fd, WritePos0),
%% file:write(Fd, Line),
%% {ok,WritePos1} = file:position(Fd,cur),
%% del_key_fd(Fd, Host, ReadPos1, WritePos1)
%% end
%% end;
%% _ ->
%% if ReadPos0 == WritePos0 ->
%% del_key_fd(Fd, Host, ReadPos1, ReadPos1);
%% true ->
%% file:position(Fd, WritePos0),
%% file:write(Fd, Line),
%% {ok,WritePos1} = file:position(Fd,cur),
%% del_key_fd(Fd, Host, ReadPos1, WritePos1)
%% end
%% end
%% end.
add_key_fd(Fd, Host, Key) ->
case Key#ssh_key.type of
rsa ->
{N,E} = Key#ssh_key.public,
DK = ssh_bits:b64_encode(
ssh_bits:encode(["ssh-rsa",E,N],
[string,mpint,mpint])),
file:write(Fd, [Host, " ssh-rsa ", DK, "\n"]);
dsa ->
{P,Q,G,Y} = Key#ssh_key.public,
DK = ssh_bits:b64_encode(
ssh_bits:encode(["ssh-dss",P,Q,G,Y],
[string,mpint,mpint,mpint,mpint])),
file:write(Fd, [Host, " ssh-dss ", DK, "\n"])
end.
%% read_pem(Cs, Type) ->
%% case read_line(Cs) of
%% {"-----BEGIN "++Rest,Cs1} ->
%% case string:tokens(Rest, " ") of
%% [Type, "PRIVATE", "KEY-----"] ->
%% read_pem64(Cs1, [], Type);
%% _ ->
%% {error, bad_format}
%% end;
%% {"",Cs1} when Cs1 =/= "" ->
%% read_pem(Cs1,Type);
%% {_,""} ->
%% {error, bad_format}
%% end.
%% read_pem64(Cs, Acc, Type) ->
%% case read_line(Cs) of
%% {"-----END "++Rest,_Cs1} ->
%% case string:tokens(Rest, " ") of
%% [Type, "PRIVATE", "KEY-----"] ->
%% {ok,ssh_bits:b64_decode(append(reverse(Acc)))};
%% Toks ->
%% error_logger:format("ssh: TOKENS=~p\n", [Toks]),
%% {error, bad_format}
%% end;
%% {B64, Cs1} when Cs1 =/= "" ->
%% read_pem64(Cs1, [B64|Acc], Type);
%% _What ->
%% {error, bad_format}
%% end.
%% read_line(Cs) -> read_line(Cs,[]).
%% read_line([$\r,$\n|T], Acc) -> {reverse(Acc), T};
%% read_line([$\n|T], Acc) -> {reverse(Acc), T};
%% read_line([C|T], Acc) -> read_line(T,[C|Acc]);
%% read_line([], Acc) -> {reverse(Acc),[]}.
lookup_user_key(User, Alg, Opts) ->
SshDir = ssh_dir({remoteuser,User}, Opts),
case lookup_user_key_f(User, SshDir, Alg, "authorized_keys", Opts) of
{ok, Key} ->
{ok, Key};
_ ->
lookup_user_key_f(User, SshDir, Alg, "authorized_keys2", Opts)
end.
lookup_user_key_f(_User, [], _Alg, _F, _Opts) ->
{error, nouserdir};
lookup_user_key_f(_User, nouserdir, _Alg, _F, _Opts) ->
{error, nouserdir};
lookup_user_key_f(_User, Dir, Alg, F, _Opts) ->
FileName = filename:join(Dir, F),
case file:open(FileName, [read]) of
{ok, Fd} ->
Res = lookup_user_key_fd(Fd, Alg),
file:close(Fd),
Res;
{error, Reason} ->
{error, {{openerr, Reason}, {file, FileName}}}
end.
lookup_user_key_fd(Fd, Alg) ->
case io:get_line(Fd, '') of
eof ->
{error, not_found};
Line ->
case string:tokens(Line, " ") of
[Alg, KeyData, _] ->
%% io:format("lookup_user_key_fd: HostList ~p Alg ~p KeyData ~p\n",
%% [HostList, Alg, KeyData]),
decode_public_key_v2(ssh_bits:b64_decode(KeyData), Alg);
_Other ->
%%?dbg(false, "key_fd Other: ~w ~w\n", [Alg, _Other]),
lookup_user_key_fd(Fd, Alg)
end
end.
encode_public_key(#ssh_key{type = rsa, public = {N, E}}) ->
ssh_bits:encode(["ssh-rsa",E,N],
[string,mpint,mpint]);
encode_public_key(#ssh_key{type = dsa, public = {P,Q,G,Y}}) ->
ssh_bits:encode(["ssh-dss",P,Q,G,Y],
[string,mpint,mpint,mpint,mpint]).
%%
%% Utils
%%
%% server use this to find individual keys for
%% an individual user when user tries to login
%% with publickey
ssh_dir({remoteuser, User}, Opts) ->
case proplists:get_value(user_dir_fun, Opts) of
undefined ->
case proplists:get_value(user_dir, Opts) of
undefined ->
default_user_dir();
Dir ->
Dir
end;
FUN ->
FUN(User)
end;
%% client use this to find client ssh keys
ssh_dir(user, Opts) ->
case proplists:get_value(user_dir, Opts, false) of
false -> default_user_dir();
D -> D
end;
%% server use this to find server host keys
ssh_dir(system, Opts) ->
proplists:get_value(system_dir, Opts, "/etc/ssh").
file_name(Type, Name, Opts) ->
FN = filename:join(ssh_dir(Type, Opts), Name),
%%?dbg(?DBG_PATHS, "file_name: ~p\n", [FN]),
FN.
default_user_dir()->
{ok,[[Home|_]]} = init:get_argument(home),
UserDir = filename:join(Home, ".ssh"),
ok = filelib:ensure_dir(filename:join(UserDir, "dummy")),
ok = file:change_mode(UserDir, ?PERM_700),
UserDir.
