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authorIngela Anderton Andin <[email protected]>2011-03-24 10:58:21 +0100
committerIngela Anderton Andin <[email protected]>2011-03-24 10:58:21 +0100
commitc4ba2c49508a02f2eef9624b06a9b91583e70e2c (patch)
tree679f594f5559314a888c15f3b82118c97ddb42fd /lib/public_key/src/pubkey_ssh.erl
parente243040fabd2701995cc4565250674d972403db2 (diff)
parentfbaa5e3ddf028ba0e2b58a19609817ee17b10c6f (diff)
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Merge branch 'ia/public_key/encode-decode-ssh/OTP-9144' into dev
* ia/public_key/encode-decode-ssh/OTP-9144: Implemented encode/decode support for ssh public key files
Diffstat (limited to 'lib/public_key/src/pubkey_ssh.erl')
-rw-r--r--lib/public_key/src/pubkey_ssh.erl431
1 files changed, 431 insertions, 0 deletions
diff --git a/lib/public_key/src/pubkey_ssh.erl b/lib/public_key/src/pubkey_ssh.erl
new file mode 100644
index 0000000000..f342eab159
--- /dev/null
+++ b/lib/public_key/src/pubkey_ssh.erl
@@ -0,0 +1,431 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2011-2011. 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%
+%%
+-module(pubkey_ssh).
+
+-include("public_key.hrl").
+
+-export([decode/2, encode/2]).
+
+-define(UINT32(X), X:32/unsigned-big-integer).
+%% Max encoded line length is 72, but conformance examples use 68
+%% Comment from rfc 4716: "The following are some examples of public
+%% key files that are compliant (note that the examples all wrap
+%% before 72 bytes to meet IETF document requirements; however, they
+%% are still compliant.)" So we choose to use 68 also.
+-define(ENCODED_LINE_LENGTH, 68).
+
+%%====================================================================
+%% Internal application API
+%%====================================================================
+
+%%--------------------------------------------------------------------
+-spec decode(binary(), public_key | ssh_file()) -> [{public_key(), Attributes::list()}].
+%%
+%% Description: Decodes a ssh file-binary.
+%%--------------------------------------------------------------------
+decode(Bin, public_key)->
+ case binary:match(Bin, begin_marker()) of
+ nomatch ->
+ openssh_decode(Bin, openssh_public_key);
+ _ ->
+ rfc4716_decode(Bin)
+ end;
+decode(Bin, rfc4716_public_key) ->
+ rfc4716_decode(Bin);
+decode(Bin, Type) ->
+ openssh_decode(Bin, Type).
+
+%%--------------------------------------------------------------------
+-spec encode([{public_key(), Attributes::list()}], ssh_file()) ->
+ binary().
+%%
+%% Description: Encodes a list of ssh file entries.
+%%--------------------------------------------------------------------
+encode(Entries, Type) ->
+ erlang:iolist_to_binary(lists:map(fun({Key, Attributes}) ->
+ do_encode(Type, Key, Attributes)
+ end, Entries)).
+
+%%--------------------------------------------------------------------
+%%% Internal functions
+%%--------------------------------------------------------------------
+begin_marker() ->
+ <<"---- BEGIN SSH2 PUBLIC KEY ----">>.
+end_marker() ->
+ <<"---- END SSH2 PUBLIC KEY ----">>.
+
+rfc4716_decode(Bin) ->
+ Lines = binary:split(Bin, <<"\n">>, [global]),
+ do_rfc4716_decode(Lines, []).
+
+do_rfc4716_decode([<<"---- BEGIN SSH2 PUBLIC KEY ----", _/binary>> | Lines], Acc) ->
+ do_rfc4716_decode(Lines, Acc);
+%% Ignore empty lines before or after begin/end - markers.
+do_rfc4716_decode([<<>> | Lines], Acc) ->
+ do_rfc4716_decode(Lines, Acc);
+do_rfc4716_decode([], Acc) ->
+ lists:reverse(Acc);
+do_rfc4716_decode(Lines, Acc) ->
+ {Headers, PubKey, Rest} = rfc4716_decode_lines(Lines, []),
+ case Headers of
+ [_|_] ->
+ do_rfc4716_decode(Rest, [{PubKey, [{headers, Headers}]} | Acc]);
+ _ ->
+ do_rfc4716_decode(Rest, [{PubKey, []} | Acc])
+ end.
+
+rfc4716_decode_lines([Line | Lines], Acc) ->
+ case binary:last(Line) of
+ $\\ ->
+ NewLine = binary:replace(Line,<<"\\">>, hd(Lines), []),
+ rfc4716_decode_lines([NewLine | tl(Lines)], Acc);
+ _ ->
+ rfc4716_decode_line(Line, Lines, Acc)
+ end.
+
+rfc4716_decode_line(Line, Lines, Acc) ->
+ case binary:split(Line, <<":">>) of
+ [Tag, Value] ->
+ rfc4716_decode_lines(Lines, [{string_decode(Tag), unicode_decode(Value)} | Acc]);
+ _ ->
+ {Body, Rest} = join_entry([Line | Lines], []),
+ {lists:reverse(Acc), rfc4716_pubkey_decode(base64:mime_decode(Body)), Rest}
+ end.
+
+join_entry([<<"---- END SSH2 PUBLIC KEY ----", _/binary>>| Lines], Entry) ->
+ {lists:reverse(Entry), Lines};
+join_entry([Line | Lines], Entry) ->
+ join_entry(Lines, [Line | Entry]).
+
+
+rfc4716_pubkey_decode(<<?UINT32(Len), Type:Len/binary,
+ ?UINT32(SizeE), E:SizeE/binary,
+ ?UINT32(SizeN), N:SizeN/binary>>) when Type == <<"ssh-rsa">> ->
+ #'RSAPublicKey'{modulus = erlint(SizeN, N),
+ publicExponent = erlint(SizeE, E)};
+
+rfc4716_pubkey_decode(<<?UINT32(Len), Type:Len/binary,
+ ?UINT32(SizeP), P:SizeP/binary,
+ ?UINT32(SizeQ), Q:SizeQ/binary,
+ ?UINT32(SizeG), G:SizeG/binary,
+ ?UINT32(SizeY), Y:SizeY/binary>>) when Type == <<"ssh-dss">> ->
+ {erlint(SizeY, Y),
+ #'Dss-Parms'{p = erlint(SizeP, P),
+ q = erlint(SizeQ, Q),
+ g = erlint(SizeG, G)}}.
+
+openssh_decode(Bin, FileType) ->
+ Lines = binary:split(Bin, <<"\n">>, [global]),
+ do_openssh_decode(FileType, Lines, []).
+
+do_openssh_decode(_, [], Acc) ->
+ lists:reverse(Acc);
+%% Ignore empty lines
+do_openssh_decode(FileType, [<<>> | Lines], Acc) ->
+ do_openssh_decode(FileType, Lines, Acc);
+%% Ignore lines that start with #
+do_openssh_decode(FileType,[<<"#", _/binary>> | Lines], Acc) ->
+ do_openssh_decode(FileType, Lines, Acc);
+do_openssh_decode(auth_keys = FileType, [Line | Lines], Acc) ->
+ Split = binary:split(Line, <<" ">>, [global]),
+ case mend_split(Split, []) of
+ %% ssh2
+ [Options, KeyType, Base64Enc, Comment] when KeyType == <<"ssh-rsa">>;
+ KeyType == <<"ssh-dss">> ->
+ do_openssh_decode(FileType, Lines,
+ [{openssh_pubkey_decode(KeyType, Base64Enc),
+ [{comment, string_decode(Comment)},
+ {options, comma_list_decode(Options)}]}
+ | Acc]);
+
+ [KeyType, Base64Enc, Comment] when KeyType == <<"ssh-rsa">>;
+ KeyType == <<"ssh-dss">> ->
+ do_openssh_decode(FileType, Lines,
+ [{openssh_pubkey_decode(KeyType, Base64Enc),
+ [{comment, string_decode(Comment)}]} | Acc]);
+ %% ssh1
+ [Options, Bits, Exponent, Modulus, Comment] ->
+ do_openssh_decode(FileType, Lines,
+ [{ssh1_rsa_pubkey_decode(Modulus, Exponent),
+ [{comment, string_decode(Comment)},
+ {options, comma_list_decode(Options)},
+ {bits, integer_decode(Bits)}]} | Acc]);
+ [Bits, Exponent, Modulus, Comment] ->
+ do_openssh_decode(FileType, Lines,
+ [{ssh1_rsa_pubkey_decode(Modulus, Exponent),
+ [{comment, string_decode(Comment)},
+ {bits, integer_decode(Bits)}]} | Acc])
+ end;
+
+do_openssh_decode(known_hosts = FileType, [Line | Lines], Acc) ->
+ case binary:split(Line, <<" ">>, [global]) of
+ %% ssh 2
+ [HostNames, KeyType, Base64Enc] when KeyType == <<"ssh-rsa">>;
+ KeyType == <<"ssh-dss">> ->
+ do_openssh_decode(FileType, Lines,
+ [{openssh_pubkey_decode(KeyType, Base64Enc),
+ [{hostnames, comma_list_decode(HostNames)}]}| Acc]);
+ [HostNames, KeyType, Base64Enc, Comment] when KeyType == <<"ssh-rsa">>;
+ KeyType == <<"ssh-dss">> ->
+ do_openssh_decode(FileType, Lines,
+ [{openssh_pubkey_decode(KeyType, Base64Enc),
+ [{comment, string_decode(Comment)},
+ {hostnames, comma_list_decode(HostNames)}]} | Acc]);
+ %% ssh 1
+ [HostNames, Bits, Exponent, Modulus, Comment] ->
+ do_openssh_decode(FileType, Lines,
+ [{ssh1_rsa_pubkey_decode(Modulus, Exponent),
+ [{comment, string_decode(Comment)},
+ {hostnames, comma_list_decode(HostNames)},
+ {bits, integer_decode(Bits)}]} | Acc]);
+ [HostNames, Bits, Exponent, Modulus] ->
+ do_openssh_decode(FileType, Lines,
+ [{ssh1_rsa_pubkey_decode(Modulus, Exponent),
+ [{comment, []},
+ {hostnames, comma_list_decode(HostNames)},
+ {bits, integer_decode(Bits)}]} | Acc])
+ end;
+
+do_openssh_decode(openssh_public_key = FileType, [Line | Lines], Acc) ->
+ case binary:split(Line, <<" ">>, [global]) of
+ [KeyType, Base64Enc, Comment0] when KeyType == <<"ssh-rsa">>;
+ KeyType == <<"ssh-dss">> ->
+ Comment = string:strip(binary_to_list(Comment0), right, $\n),
+ do_openssh_decode(FileType, Lines,
+ [{openssh_pubkey_decode(KeyType, Base64Enc),
+ [{comment, Comment}]} | Acc])
+ end.
+
+
+openssh_pubkey_decode(<<"ssh-rsa">>, Base64Enc) ->
+ <<?UINT32(StrLen), _:StrLen/binary,
+ ?UINT32(SizeE), E:SizeE/binary,
+ ?UINT32(SizeN), N:SizeN/binary>>
+ = base64:mime_decode(Base64Enc),
+ #'RSAPublicKey'{modulus = erlint(SizeN, N),
+ publicExponent = erlint(SizeE, E)};
+
+openssh_pubkey_decode(<<"ssh-dss">>, Base64Enc) ->
+ <<?UINT32(StrLen), _:StrLen/binary,
+ ?UINT32(SizeP), P:SizeP/binary,
+ ?UINT32(SizeQ), Q:SizeQ/binary,
+ ?UINT32(SizeG), G:SizeG/binary,
+ ?UINT32(SizeY), Y:SizeY/binary>>
+ = base64:mime_decode(Base64Enc),
+ {erlint(SizeY, Y),
+ #'Dss-Parms'{p = erlint(SizeP, P),
+ q = erlint(SizeQ, Q),
+ g = erlint(SizeG, G)}}.
+
+erlint(MPIntSize, MPIntValue) ->
+ Bits= MPIntSize * 8,
+ <<Integer:Bits/integer>> = MPIntValue,
+ Integer.
+
+ssh1_rsa_pubkey_decode(MBin, EBin) ->
+ #'RSAPublicKey'{modulus = integer_decode(MBin),
+ publicExponent = integer_decode(EBin)}.
+
+integer_decode(BinStr) ->
+ list_to_integer(binary_to_list(BinStr)).
+
+string_decode(BinStr) ->
+ binary_to_list(BinStr).
+
+unicode_decode(BinStr) ->
+ unicode:characters_to_list(BinStr).
+
+comma_list_decode(BinOpts) ->
+ CommaList = binary:split(BinOpts, <<",">>, [global]),
+ lists:map(fun(Item) ->
+ binary_to_list(Item)
+ end, CommaList).
+
+do_encode(rfc4716_public_key, Key, Attributes) ->
+ rfc4716_encode(Key, proplists:get_value(headers, Attributes, []), []);
+
+do_encode(Type, Key, Attributes) ->
+ openssh_encode(Type, Key, Attributes).
+
+rfc4716_encode(Key, [],[]) ->
+ erlang:iolist_to_binary([begin_marker(),"\n",
+ split_lines(base64:encode(ssh2_pubkey_encode(Key))),
+ "\n", end_marker(), "\n"]);
+rfc4716_encode(Key, [], [_|_] = Acc) ->
+ erlang:iolist_to_binary([begin_marker(), "\n",
+ lists:reverse(Acc),
+ split_lines(base64:encode(ssh2_pubkey_encode(Key))),
+ "\n", end_marker(), "\n"]);
+rfc4716_encode(Key, [ Header | Headers], Acc) ->
+ LinesStr = rfc4716_encode_header(Header),
+ rfc4716_encode(Key, Headers, [LinesStr | Acc]).
+
+rfc4716_encode_header({Tag, Value}) ->
+ TagLen = length(Tag),
+ ValueLen = length(Value),
+ case TagLen + 1 + ValueLen of
+ N when N > ?ENCODED_LINE_LENGTH ->
+ NumOfChars = ?ENCODED_LINE_LENGTH - (TagLen + 1),
+ {First, Rest} = lists:split(NumOfChars, Value),
+ [Tag,":" , First, [$\\], "\n", rfc4716_encode_value(Rest) , "\n"];
+ _ ->
+ [Tag, ":", Value, "\n"]
+ end.
+
+rfc4716_encode_value(Value) ->
+ case length(Value) of
+ N when N > ?ENCODED_LINE_LENGTH ->
+ {First, Rest} = lists:split(?ENCODED_LINE_LENGTH, Value),
+ [First, [$\\], "\n", rfc4716_encode_value(Rest)];
+ _ ->
+ Value
+ end.
+
+openssh_encode(openssh_public_key, Key, Attributes) ->
+ Comment = proplists:get_value(comment, Attributes),
+ Enc = base64:encode(ssh2_pubkey_encode(Key)),
+ erlang:iolist_to_binary([key_type(Key), " ", Enc, " ", Comment, "\n"]);
+
+openssh_encode(auth_keys, Key, Attributes) ->
+ Comment = proplists:get_value(comment, Attributes, ""),
+ Options = proplists:get_value(options, Attributes, undefined),
+ Bits = proplists:get_value(bits, Attributes, undefined),
+ case Bits of
+ undefined ->
+ openssh_ssh2_auth_keys_encode(Options, Key, Comment);
+ _ ->
+ openssh_ssh1_auth_keys_encode(Options, Bits, Key, Comment)
+ end;
+openssh_encode(known_hosts, Key, Attributes) ->
+ Comment = proplists:get_value(comment, Attributes, ""),
+ Hostnames = proplists:get_value(hostnames, Attributes),
+ Bits = proplists:get_value(bits, Attributes, undefined),
+ case Bits of
+ undefined ->
+ openssh_ssh2_know_hosts_encode(Hostnames, Key, Comment);
+ _ ->
+ openssh_ssh1_known_hosts_encode(Hostnames, Bits, Key, Comment)
+ end.
+
+openssh_ssh2_auth_keys_encode(undefined, Key, Comment) ->
+ erlang:iolist_to_binary([key_type(Key)," ", base64:encode(ssh2_pubkey_encode(Key)), line_end(Comment)]);
+openssh_ssh2_auth_keys_encode(Options, Key, Comment) ->
+ erlang:iolist_to_binary([comma_list_encode(Options, []), " ",
+ key_type(Key)," ", base64:encode(ssh2_pubkey_encode(Key)), line_end(Comment)]).
+
+openssh_ssh1_auth_keys_encode(undefined, Bits,
+ #'RSAPublicKey'{modulus = N, publicExponent = E},
+ Comment) ->
+ erlang:iolist_to_binary([integer_to_list(Bits), " ", integer_to_list(E), " ", integer_to_list(N),
+ line_end(Comment)]);
+openssh_ssh1_auth_keys_encode(Options, Bits,
+ #'RSAPublicKey'{modulus = N, publicExponent = E},
+ Comment) ->
+ erlang:iolist_to_binary([comma_list_encode(Options, []), " ", integer_to_list(Bits),
+ " ", integer_to_list(E), " ", integer_to_list(N), line_end(Comment)]).
+
+openssh_ssh2_know_hosts_encode(Hostnames, Key, Comment) ->
+ erlang:iolist_to_binary([comma_list_encode(Hostnames, []), " ",
+ key_type(Key)," ", base64:encode(ssh2_pubkey_encode(Key)), line_end(Comment)]).
+
+openssh_ssh1_known_hosts_encode(Hostnames, Bits,
+ #'RSAPublicKey'{modulus = N, publicExponent = E},
+ Comment) ->
+ erlang:iolist_to_binary([comma_list_encode(Hostnames, [])," ", integer_to_list(Bits)," ",
+ integer_to_list(E)," ", integer_to_list(N), line_end(Comment)]).
+
+line_end("") ->
+ "\n";
+line_end(Comment) ->
+ [" ", Comment, "\n"].
+
+key_type(#'RSAPublicKey'{}) ->
+ <<"ssh-rsa">>;
+key_type({_, #'Dss-Parms'{}}) ->
+ <<"ssh-dss">>.
+
+comma_list_encode([Option], []) ->
+ Option;
+comma_list_encode([Option], Acc) ->
+ Acc ++ "," ++ Option;
+comma_list_encode([Option | Rest], []) ->
+ comma_list_encode(Rest, Option);
+comma_list_encode([Option | Rest], Acc) ->
+ comma_list_encode(Rest, Acc ++ "," ++ Option).
+
+ssh2_pubkey_encode(#'RSAPublicKey'{modulus = N, publicExponent = E}) ->
+ TypeStr = <<"ssh-rsa">>,
+ StrLen = size(TypeStr),
+ EBin = crypto:mpint(E),
+ NBin = crypto:mpint(N),
+ <<?UINT32(StrLen), TypeStr:StrLen/binary,
+ EBin/binary,
+ NBin/binary>>;
+ssh2_pubkey_encode({Y, #'Dss-Parms'{p = P, q = Q, g = G}}) ->
+ TypeStr = <<"ssh-dss">>,
+ StrLen = size(TypeStr),
+ PBin = crypto:mpint(P),
+ QBin = crypto:mpint(Q),
+ GBin = crypto:mpint(G),
+ YBin = crypto:mpint(Y),
+ <<?UINT32(StrLen), TypeStr:StrLen/binary,
+ PBin/binary,
+ QBin/binary,
+ GBin/binary,
+ YBin/binary>>.
+
+mend_split([Part1, Part2 | Rest] = List, Acc) ->
+ case option_end(Part1, Part2) of
+ true ->
+ lists:reverse(Acc) ++ List;
+ false ->
+ case length(binary:matches(Part1, <<"\"">>)) of
+ N when N rem 2 == 0 ->
+ mend_split(Rest, [Part1 | Acc]);
+ _ ->
+ mend_split([<<Part1/binary, Part2/binary>> | Rest], Acc)
+ end
+ end.
+
+option_end(Part1, Part2) ->
+ (is_key_field(Part1) orelse is_bits_field(Part1))
+ orelse
+ (is_key_field(Part2) orelse is_bits_field(Part2)).
+
+is_key_field(<<"ssh-dss">>) ->
+ true;
+is_key_field(<<"ssh-rsa">>) ->
+ true;
+is_key_field(_) ->
+ false.
+
+is_bits_field(Part) ->
+ try list_to_integer(binary_to_list(Part)) of
+ _ ->
+ true
+ catch _:_ ->
+ false
+ end.
+
+split_lines(<<Text:?ENCODED_LINE_LENGTH/binary>>) ->
+ [Text];
+split_lines(<<Text:?ENCODED_LINE_LENGTH/binary, Rest/binary>>) ->
+ [Text, $\n | split_lines(Rest)];
+split_lines(Bin) ->
+ [Bin].