anchor.diff:  select_by_keylen(_Min, _N, _Max, [],GPprev) ->
       %% is between Min and Max
       GPprev.
  -
  -
  -%%--------------------------------------------------------------------
  -%%% 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(?b64mime_dec(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(BinKey) -> ssh2_pubkey_decode(BinKey).
  -
  -
  -%% From https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key
  -new_openssh_decode(<<"openssh-key-v1",0,
  -                     ?DEC_BIN(CipherName, _L1),
  -                     ?DEC_BIN(KdfName, _L2),
  -                     ?DEC_BIN(KdfOptions, _L3),
  -                     ?UINT32(N),      % number of keys
  -                     ?DEC_BIN(PublicKey, _L4),
  -                     ?DEC_BIN(Encrypted, _L5),
  -                     _Rest/binary
  -                   >>) ->
  -    %%io:format("CipherName = ~p~nKdfName = ~p~nKdfOptions = ~p~nPublicKey = ~p~nN = ~p~nEncrypted = ~p~nRest = ~p~n", [CipherName, KdfName, KdfOptions, PublicKey, N, Encrypted, _Rest]),
  -    new_openssh_decode(CipherName, KdfName, KdfOptions, PublicKey, N, Encrypted).
  -
  -new_openssh_decode(<<"none">>, <<"none">>, <<"">>, _PublicKey, 1,
  -                   <<?UINT32(CheckInt),
  -                     ?UINT32(CheckInt),
  -                     ?DEC_BIN(Type, _Lt),
  -                     ?DEC_BIN(PubKey, _Lpu),
  -                     ?DEC_BIN(PrivPubKey, _Lpripub),
  -                     ?DEC_BIN(_Comment,    _C1),
  -                     _Pad/binary>>) ->
  -    case {Type,PrivPubKey} of
  -        {<<"ssh-ed25519">>,
  -         <<PrivKey:32/binary, PubKey:32/binary>>} ->
  -            {ed_pri, ed25519, PubKey, PrivKey}; 
  -
  -        {<<"ssh-ed448">>,
  -         <<PrivKey:57/binary, PubKey/binary>>} -> % "Intelligent" guess from
  -                                                % https://tools.ietf.org/html/draft-ietf-curdle-ssh-ed25519-ed448
  -            {ed_pri, ed448, PubKey, PrivKey}
  -    end.
  -
  -
  -new_openssh_encode({ed_pri,_,PubKey,PrivKey}=Key) ->
  -    Type = key_type(Key),
  -    CheckInt = 17*256+17, %crypto:strong_rand_bytes(4),
  -    Comment = <<>>,
  -    PublicKey = <<?STRING(Type),?STRING(PubKey)>>,
  -    CipherName = <<"none">>,
  -    KdfName = <<"none">>,
  -    KdfOptions = <<>>,
  -    BlockSize = 8, % Crypto dependent
  -    NumKeys = 1,
  -    Encrypted0 = <<?UINT32(CheckInt),
  -                   ?UINT32(CheckInt),
  -                   ?STRING(Type),
  -                   ?STRING(PubKey),
  -                   ?STRING(<<PrivKey/binary,PubKey/binary>>),
  -                   ?STRING(Comment)
  -                >>,
  -    Pad = pad(size(Encrypted0), BlockSize),
  -    Encrypted = <<Encrypted0/binary, Pad/binary>>,
  -    <<"openssh-key-v1",0,
  -      ?STRING(CipherName),
  -      ?STRING(KdfName),
  -      ?STRING(KdfOptions),
  -      ?UINT32(NumKeys),
  -      ?STRING(PublicKey),
  -      ?STRING(Encrypted)>>.
  -
  -pad(N, BlockSize) when N>BlockSize -> pad(N rem BlockSize, BlockSize);
  -pad(N, BlockSize) -> list_to_binary(lists:seq(1,BlockSize-N)).
  -
  -
  -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) ->
  -    case decode_auth_keys(Line) of
  -	{ssh2,  {options, [Options, KeyType, Base64Enc| Comment]}} ->
  -	    do_openssh_decode(FileType, Lines,
  -			      [{openssh_pubkey_decode(KeyType, Base64Enc), 
  -				decode_comment(Comment) ++ [{options, comma_list_decode(Options)}]} | Acc]);
  -	{ssh2, {no_options, [KeyType, Base64Enc| Comment]}} ->
  -	    do_openssh_decode(FileType, Lines,
  -			      [{openssh_pubkey_decode(KeyType, Base64Enc), 
  -				decode_comment(Comment)} | Acc]);
  -	{ssh1, {options, [Options, Bits, Exponent, Modulus | Comment]}} ->
  -	    do_openssh_decode(FileType, Lines,
  -			      [{ssh1_rsa_pubkey_decode(Modulus, Exponent),
  -				decode_comment(Comment) ++ [{options, comma_list_decode(Options)},
  -							    {bits, integer_decode(Bits)}]
  -			       } | Acc]);
  -	{ssh1, {no_options, [Bits, Exponent, Modulus | Comment]}} ->
  -	    do_openssh_decode(FileType, Lines,
  -			      [{ssh1_rsa_pubkey_decode(Modulus, Exponent),
  -				decode_comment(Comment) ++ [{bits, integer_decode(Bits)}]
  -			       } | Acc])
  -    end;
  -
  -do_openssh_decode(known_hosts = FileType, [Line | Lines], Acc) ->
  -    case decode_known_hosts(Line) of
  -	{ssh2, [HostNames, KeyType, Base64Enc| Comment]} ->
  -	    do_openssh_decode(FileType, Lines,
  -			      [{openssh_pubkey_decode(KeyType, Base64Enc), 
  -				decode_comment(Comment) ++ 
  -				    [{hostnames, comma_list_decode(HostNames)}]}| Acc]);
  -	{ssh1, [HostNames, Bits, Exponent, Modulus | Comment]} ->
  -	    do_openssh_decode(FileType, Lines,
  -			      [{ssh1_rsa_pubkey_decode(Modulus, Exponent), 
  -				decode_comment(Comment) ++ 
  -				    [{hostnames, comma_list_decode(HostNames)},
  -				     {bits, integer_decode(Bits)}]} 
  -			       | Acc])
  -    end;
  -
  -do_openssh_decode(openssh_public_key = FileType, [Line | Lines], Acc) ->
  -    [KeyType, Base64Enc | Comment0] = split_n(2, Line, []),
  -    KnownKeyType = 
  -	case KeyType of
  -	    <<"ssh-rsa">> -> true;
  -	    <<"ssh-dss">> -> true;
  -	    <<"ecdsa-sha2-",Curve/binary>> -> is_ssh_curvename(Curve);
  -            <<"ssh-ed25519">> -> true;
  -            <<"ssh-ed448">> -> true;
  -	    _ -> false
  -	end,
  -
  -    case Comment0 of
  -	[] when KnownKeyType==true ->
  -	    do_openssh_decode(FileType, Lines,
  -			      [{openssh_pubkey_decode(KeyType, Base64Enc),
  -				[]} | Acc]);
  -	_ when KnownKeyType==true ->
  -	    Comment = string:strip(string_decode(iolist_to_binary(Comment0)), right, $\n),
  -	    do_openssh_decode(FileType, Lines,
  -			      [{openssh_pubkey_decode(KeyType, Base64Enc),
  -				[{comment, Comment}]} | Acc]);
  -        _ when KnownKeyType==false ->
  -                  do_openssh_decode(FileType, Lines,  Acc)
  -    end.
  -
  -
  -decode_comment([]) ->
  -    [];
  -decode_comment(Comment) ->
  -    [{comment, string_decode(iolist_to_binary(Comment))}].
  -
  -
  -openssh_pubkey_decode(Type,  Base64Enc) ->
  -    try
  -        <<?DEC_BIN(Type,_TL), Bin/binary>> = ?b64mime_dec(Base64Enc),
  -	ssh2_pubkey_decode(Type,  Bin)
  -    catch
  -	_:_ ->
  -	    {Type, ?b64mime_dec(Base64Enc)}
  -    end.
  -
  -
  -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) ->
  -    unicode_decode(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, [],[]) ->
  -    iolist_to_binary([begin_marker(),"\n",
  -			     split_lines(?b64enc(ssh2_pubkey_encode(Key))),
  -			     "\n", end_marker(), "\n"]);
  -rfc4716_encode(Key, [], [_|_] = Acc) ->
  -    iolist_to_binary([begin_marker(), "\n",
  -			     lists:reverse(Acc),
  -			     split_lines(?b64enc(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 = ?b64enc(ssh2_pubkey_encode(Key)),
  -    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) ->
  -    iolist_to_binary([key_type(Key)," ",  ?b64enc(ssh2_pubkey_encode(Key)), line_end(Comment)]);
  -openssh_ssh2_auth_keys_encode(Options, Key, Comment) ->
  -    iolist_to_binary([comma_list_encode(Options, []), " ",
  -			     key_type(Key)," ", ?b64enc(ssh2_pubkey_encode(Key)), line_end(Comment)]).
  -
  -openssh_ssh1_auth_keys_encode(undefined, Bits,
  -			      #'RSAPublicKey'{modulus = N, publicExponent = E},
  -			      Comment) ->
  -    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) ->
  -    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) ->
  -    iolist_to_binary([comma_list_encode(Hostnames, []), " ",
  -			     key_type(Key)," ",  ?b64enc(ssh2_pubkey_encode(Key)), line_end(Comment)]).
  -
  -openssh_ssh1_known_hosts_encode(Hostnames, Bits,
  -				#'RSAPublicKey'{modulus = N, publicExponent = E},
  -				Comment) ->
  -    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">>;
  -key_type({ed_pub,ed25519,_}) -> <<"ssh-ed25519">>;
  -key_type({ed_pub,ed448,_}) -> <<"ssh-ed448">>;
  -key_type({ed_pri,ed25519,_,_}) -> <<"ssh-ed25519">>;
  -key_type({ed_pri,ed448,_,_}) -> <<"ssh-ed448">>;
  -key_type({#'ECPoint'{}, {namedCurve,Curve}}) -> <<"ecdsa-sha2-", (public_key:oid2ssh_curvename(Curve))/binary>>.
  -
  -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}) ->
  -    <<?STRING(<<"ssh-rsa">>), ?Empint(E), ?Empint(N)>>;
  -ssh2_pubkey_encode({Y,  #'Dss-Parms'{p = P, q = Q, g = G}}) ->
  -    <<?STRING(<<"ssh-dss">>), ?Empint(P), ?Empint(Q), ?Empint(G), ?Empint(Y)>>;
  -ssh2_pubkey_encode(Key={#'ECPoint'{point = Q}, {namedCurve,OID}}) ->
  -    Curve = public_key:oid2ssh_curvename(OID),
  -    <<?STRING(key_type(Key)), ?Estring(Curve), ?Estring(Q)>>;
  -ssh2_pubkey_encode({ed_pub, ed25519, Key}) ->
  -    <<?STRING(<<"ssh-ed25519">>), ?Estring(Key)>>;
  -ssh2_pubkey_encode({ed_pub, ed448, Key}) ->
  -    <<?STRING(<<"ssh-ed448">>), ?Estring(Key)>>.
  -
  -
  -
  -ssh2_pubkey_decode(<<?DEC_BIN(Type,_TL), Bin/binary>>) ->
  -    ssh2_pubkey_decode(Type, Bin).
  -
  -%% ssh2_pubkey_decode(<<"rsa-sha2-256">>, Bin) -> ssh2_pubkey_decode(<<"ssh-rsa">>, Bin);
  -%% ssh2_pubkey_decode(<<"rsa-sha2-512">>, Bin) -> ssh2_pubkey_decode(<<"ssh-rsa">>, Bin);
  -ssh2_pubkey_decode(<<"ssh-rsa">>,
  -                   <<?DEC_INT(E, _EL),
  -                     ?DEC_INT(N, _NL)>>) ->
  -    #'RSAPublicKey'{modulus = N,
  -		    publicExponent = E};
  -
  -ssh2_pubkey_decode(<<"ssh-dss">>,
  -                   <<?DEC_INT(P, _PL),
  -                     ?DEC_INT(Q, _QL),
  -                     ?DEC_INT(G, _GL),
  -                     ?DEC_INT(Y, _YL)>>) ->
  -    {Y, #'Dss-Parms'{p = P,
  -                     q = Q,
  -                     g = G}};
  -
  -ssh2_pubkey_decode(<<"ecdsa-sha2-",Id/binary>>,
  -                   <<?DEC_BIN(Id, _IL),
  -                     ?DEC_BIN(Q, _QL)>>) ->
  -    {#'ECPoint'{point = Q}, {namedCurve,public_key:ssh_curvename2oid(Id)}};
  -
  -ssh2_pubkey_decode(<<"ssh-ed25519">>,
  -                   <<?DEC_BIN(Key, _L)>>) ->
  -    {ed_pub, ed25519, Key};
  -
  -ssh2_pubkey_decode(<<"ssh-ed448">>,
  -                   <<?DEC_BIN(Key, _L)>>) ->
  -    {ed_pub, ed448, Key}.
  -
  -
  -
  -
  -is_key_field(<<"ssh-dss">>) ->  true;
  -is_key_field(<<"ssh-rsa">>) ->  true;
  -is_key_field(<<"ssh-ed25519">>) -> true;
  -is_key_field(<<"ssh-ed448">>) -> true;
  -is_key_field(<<"ecdsa-sha2-",Id/binary>>) -> is_ssh_curvename(Id);
  -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].
  -
  -decode_auth_keys(Line) ->
  -    [First, Rest] = binary:split(Line, <<" ">>, []),
  -    case is_key_field(First) of
  -	true  ->
  -	    {ssh2, decode_auth_keys_ssh2(First, Rest)};
  -	false ->
  -	    case is_bits_field(First) of
  -		true ->
  -		    {ssh1, decode_auth_keys_ssh1(First, Rest)};
  -		false ->
  -		    decode_auth_keys(First, Rest)
  -	    end
  -    end.
  -
  -decode_auth_keys(First, Line) ->
  -    [Second, Rest] = binary:split(Line, <<" ">>, []),
  -    case is_key_field(Second) of
  -	true -> 
  -	    {ssh2, decode_auth_keys_ssh2(First, Second, Rest)};
  -	false ->
  -	    case is_bits_field(Second) of
  -		true -> 
  -		    {ssh1, decode_auth_keys_ssh1(First, Second, Rest)};
  -		false ->
  -		    decode_auth_keys(<<First/binary, Second/binary>>, Rest)
  -	    end
  -    end.
  -
  -decode_auth_keys_ssh2(KeyType, Rest) ->
  -    {no_options, [KeyType | split_n(1, Rest,  [])]}.
  -
  -decode_auth_keys_ssh2(Options, Next, Rest) ->
  -    {options, [Options, Next | split_n(1, Rest,  [])]}.
  -
  -decode_auth_keys_ssh1(Options, Next, Rest) ->
  -    {options, [Options, Next | split_n(2, Rest,  [])]}.
  -
  -decode_auth_keys_ssh1(First, Rest) ->
  -    {no_options, [First | split_n(2, Rest, [])]}.
  -
  -decode_known_hosts(Line) ->
  -    [First, Rest] = binary:split(Line, <<" ">>, []),
  -    [Second, Rest1] = binary:split(Rest, <<" ">>, []),
  -
  -    case is_bits_field(Second) of
  -	true ->
  -	    {ssh1, decode_known_hosts_ssh1(First, Second, Rest1)};
  -	false ->
  -	    {ssh2, decode_known_hosts_ssh2(First, Second, Rest1)}
  -    end.
  -
  -decode_known_hosts_ssh1(Hostnames, Bits, Rest) ->
  -    [Hostnames, Bits | split_n(2, Rest,  [])].
  -
  -decode_known_hosts_ssh2(Hostnames, KeyType, Rest) ->
  -    [Hostnames, KeyType | split_n(1, Rest,  [])].
  -
  -split_n(0, <<>>, Acc) ->
  -    lists:reverse(Acc);
  -split_n(0, Bin, Acc) ->
  -    lists:reverse([Bin | Acc]);
  -split_n(N, Bin, Acc) ->
  -    case binary:split(Bin, <<" ">>, []) of
  -	[First, Rest] ->
  -	    split_n(N-1, Rest, [First | Acc]);
  -	[Last] ->
  -	    split_n(0, <<>>, [Last | Acc])
  -    end.
  -%% large integer in a binary with 32bit length
  -%% MP representation  (SSH2)
  -mpint(X) when X < 0 -> mpint_neg(X);
  -mpint(X) -> mpint_pos(X).
  -
  -mpint_neg(X) ->
  -    Bin = int_to_bin_neg(X, []),
  -    <<?STRING(Bin)>>.
  -    
  -mpint_pos(X) ->
  -    Bin = int_to_bin_pos(X, []),
  -    <<MSB,_/binary>> = Bin,
  -    if MSB band 16#80 == 16#80 ->
  -            B = << 0, Bin/binary>>,
  -	    <<?STRING(B)>>;
  -       true ->
  -	    <<?STRING(Bin)>>
  -    end.
  -
  -int_to_bin_pos(0,Ds=[_|_]) ->
  -    list_to_binary(Ds);
  -int_to_bin_pos(X,Ds) ->
  -    int_to_bin_pos(X bsr 8, [(X band 255)|Ds]).
  -
  -int_to_bin_neg(-1, Ds=[MSB|_]) when MSB >= 16#80 ->
  -    list_to_binary(Ds);
  -int_to_bin_neg(X,Ds) ->
  -    int_to_bin_neg(X bsr 8, [(X band 255)|Ds]).
  -
  -
  -string(X) when is_binary(X) ->
  -    << ?STRING(X) >>;
  -string(X) ->
  -    B = list_to_binary(X),
  -    << ?STRING(B) >>.
  -
  -is_ssh_curvename(Id) -> try public_key:ssh_curvename2oid(Id) of _ -> true
  -			catch _:_  -> false
  -			end.
  -
  
positive.code: %%
  -module(pubkey_ssh).
  
  -include("public_key.hrl").
  -include("pubkey_moduli.hrl").
  
  
  -export([decode/2, encode/2,
  	 dh_gex_group/4, 
  	 dh_gex_group_sizes/0,
  pad/2,         new_openssh_encode/1, new_openssh_decode/1  % For test and experiments
  	]).
  
  -define(UINT32(X), X:32/unsigned-big-integer).
  -define(STRING(X), ?UINT32((byte_size(X))), (X)/binary).
  
  -define(DEC_BIN(X,Len),   ?UINT32(Len), X:Len/binary ).
  -define(DEC_MPINT(I,Len), ?DEC_INT(I,Len) ).
  -define(DEC_INT(I,Len),   ?UINT32(Len), I:Len/big-signed-integer-unit:8 ).
  
  -define(Empint(X),  (mpint(X))/binary ).
  -define(Estring(X), (string(X))/binary ).
  
  -define(b64enc(X), base64:encode(iolist_to_binary(X)) ).
  -define(b64mime_dec(X), base64:mime_decode(iolist_to_binary(X)) ).
  
  %% 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
  %%====================================================================
  
  %%--------------------------------------------------------------------
  %% Description: Decodes a ssh file-binary.
  %%--------------------------------------------------------------------
  decode(Bin, public_key)->
      PKtype =
          case binary:match(Bin, begin_marker()) of
              nomatch -> openssh_public_key;
              _ -> rfc4716_public_key
          end,
      decode(Bin, PKtype);
  decode(Bin, rfc4716_public_key) ->
      rfc4716_decode(Bin);
  decode(Bin, ssh2_pubkey) ->
      ssh2_pubkey_decode(Bin);
  decode(Bin, new_openssh) ->
      new_openssh_decode(Bin);
  decode(Bin, Type) ->
      openssh_decode(Bin, Type).
  
  %%--------------------------------------------------------------------
  %% Description: Encodes a list of ssh file entries.
  %%--------------------------------------------------------------------
  encode(Bin, ssh2_pubkey) ->
      ssh2_pubkey_encode(Bin);
  encode(Entries, Type) ->
      iolist_to_binary(lists:map(fun({Key, Attributes}) ->
  					      do_encode(Type, Key, Attributes)
  				      end, Entries)).
  
  %%--------------------------------------------------------------------
  %% Description: Returns Generator and Modulus given MinSize, WantedSize
  
negative.code: 
  dh_gex_group_sizes()->
      [KeyLen || {KeyLen,_} <- ?dh_default_groups].
  
  
  %%--------------------------------------------------------------------
  %%% Internal functions
  %%--------------------------------------------------------------------
  
  %% Select the one with K closest to N but within the interval [Min,Max]
      
  