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Diffstat (limited to 'lib/ssh/test/ssh_test_lib.erl')
| -rw-r--r-- | lib/ssh/test/ssh_test_lib.erl | 684 |
1 files changed, 684 insertions, 0 deletions
diff --git a/lib/ssh/test/ssh_test_lib.erl b/lib/ssh/test/ssh_test_lib.erl new file mode 100644 index 0000000000..425fae22c1 --- /dev/null +++ b/lib/ssh/test/ssh_test_lib.erl @@ -0,0 +1,684 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2004-2011. 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(ssh_test_lib). + +%% Note: This directive should only be used in test suites. +-compile(export_all). + +-include_lib("public_key/include/public_key.hrl"). +-include("test_server.hrl"). +-include("test_server_line.hrl"). + +-define(TIMEOUT, 50000). + +connect(Options) -> + connect(hostname(), inet_port(), Options). + +connect(Port, Options) when is_integer(Port) -> + connect(hostname(), Port, Options); +connect(any, Options) -> + connect(hostname(), inet_port(), Options); +connect(Host, Options) -> + connect(Host, inet_port(), Options). + +connect(any, Port, Options) -> + connect(hostname(), Port, Options); +connect(Host, Port, Options) -> + case ssh:connect(Host, Port, Options) of + {ok, ConnectionRef} -> + ConnectionRef; + Error -> + Error + end. + +daemon(Options) -> + daemon(any, inet_port(), Options). + +daemon(Port, Options) when is_integer(Port) -> + daemon(any, Port, Options); +daemon(Host, Options) -> + daemon(Host, inet_port(), Options). + +daemon(Host, Port, Options) -> + case ssh:daemon(Host, Port, Options) of + {ok, Pid} when Host == any -> + {Pid, hostname(), Port}; + {ok, Pid} -> + {Pid, Host, Port}; + Error -> + Error + end. + + + + +start_shell(Port, IOServer) -> + spawn_link(?MODULE, init_shell, [Port, IOServer]). + +init_shell(Port, IOServer) -> + Host = hostname(), + UserDir = get_user_dir(), + Options = [{user_interaction, false}, {silently_accept_hosts, + true}] ++ UserDir, + group_leader(IOServer, self()), + loop_shell(Host, Port, Options). + +loop_shell(Host, Port, Options) -> + ssh:shell(Host, Port, Options). + +start_io_server() -> + spawn_link(?MODULE, init_io_server, [self()]). + +init_io_server(TestCase) -> + process_flag(trap_exit, true), + loop_io_server(TestCase, []). + +loop_io_server(TestCase, Buff0) -> + receive + {input, TestCase, Line} -> + %io:format("~p~n",[{input, TestCase, Line}]), + loop_io_server(TestCase, Buff0 ++ [Line]); + {io_request, From, ReplyAs, Request} -> + %io:format("request -> ~p~n",[Request]), + {ok, Reply, Buff} = io_request(Request, TestCase, From, + ReplyAs, Buff0), + %io:format("reply -> ~p~n",[Reply]), + io_reply(From, ReplyAs, Reply), + loop_io_server(TestCase, Buff); + {'EXIT',_, _} -> + erlang:display('EXIT'), + ok + end. + +io_request({put_chars, Chars}, TestCase, _, _, Buff) -> + reply(TestCase, Chars), + {ok, ok, Buff}; +io_request({put_chars, Enc, Chars}, TestCase, _, _, Buff) -> + reply(TestCase, unicode:characters_to_binary(Chars,Enc,latin1)), + {ok, ok, Buff}; + +io_request({get_line, _} = Request, _, From, ReplyAs, [] = Buff) -> + erlang:send_after(1000, self(), {io_request, From, ReplyAs, Request}), + {ok, [], Buff}; +io_request({get_line, _Enc, _Prompt} = Request, _, From, ReplyAs, [] = Buff) -> + erlang:send_after(1000, self(), {io_request, From, ReplyAs, Request}), + {ok, [], Buff}; + +io_request({get_line, _Enc,_}, _, _, _, [Line | Buff]) -> + {ok, Line, Buff}. + +io_reply(_, _, []) -> + ok; +io_reply(From, ReplyAs, Reply) -> + From ! {io_reply, ReplyAs, Reply}. + +reply(_, []) -> + ok; +reply(TestCase, Result) -> + TestCase ! Result. + +receive_exec_result(Msg) -> + test_server:format("Expect data! ~p", [Msg]), + receive + Msg -> + test_server:format("1: Collected data ~p", [Msg]), + expected; + Other -> + {unexpected_msg, Other} + end. +receive_exec_end(ConnectionRef, ChannelId) -> + Eof = {ssh_cm, ConnectionRef, {eof, ChannelId}}, + ExitStatus = {ssh_cm, ConnectionRef, {exit_status, ChannelId, 0}}, + Closed = {ssh_cm, ConnectionRef,{closed, ChannelId}}, + case receive_exec_result(ExitStatus) of + {unexpected_msg, Eof} -> %% Open ssh seems to not allways send these messages + %% in the same order! + test_server:format("2: Collected data ~p", [Eof]), + case receive_exec_result(ExitStatus) of + expected -> + expected = receive_exec_result(Closed); + {unexpected_msg, Closed} -> + test_server:format("3: Collected data ~p", [Closed]) + end; + expected -> + test_server:format("4: Collected data ~p", [ExitStatus]), + expected = receive_exec_result(Eof), + expected = receive_exec_result(Closed); + Other -> + test_server:fail({unexpected_msg, Other}) + end. + +receive_exec_result(Data, ConnectionRef, ChannelId) -> + Eof = {ssh_cm, ConnectionRef, {eof, ChannelId}}, + Closed = {ssh_cm, ConnectionRef,{closed, ChannelId}}, + expected = receive_exec_result(Data), + expected = receive_exec_result(Eof), + expected = receive_exec_result(Closed). + + +inet_port()-> + {ok, Socket} = gen_tcp:listen(0, [{reuseaddr, true}]), + {ok, Port} = inet:port(Socket), + gen_tcp:close(Socket), + Port. + + +%% copy private keys to given dir from ~/.ssh +get_id_keys(DstDir) -> + SrcDir = filename:join(os:getenv("HOME"), ".ssh"), + RsaOk = copyfile(SrcDir, DstDir, "id_rsa"), + DsaOk = copyfile(SrcDir, DstDir, "id_dsa"), + case {RsaOk, DsaOk} of + {{ok, _}, {ok, _}} -> {ok, both}; + {{ok, _}, _} -> {ok, rsa}; + {_, {ok, _}} -> {ok, dsa}; + {Error, _} -> Error + end. + +remove_id_keys(Dir) -> + file:delete(filename:join(Dir, "id_rsa")), + file:delete(filename:join(Dir, "id_dsa")). + +copyfile(SrcDir, DstDir, Fn) -> + file:copy(filename:join(SrcDir, Fn), + filename:join(DstDir, Fn)). + +failfun(_User, {authmethod,none}) -> + ok; +failfun(User, Reason) -> + error_logger:format("~p failed XXX to login: ~p~n", [User, Reason]). + +hostname() -> + {ok,Host} = inet:gethostname(), + Host. + +known_hosts(BR) -> + KnownHosts = ssh_file:file_name(user, "known_hosts", []), + B = KnownHosts ++ "xxx", + case BR of + backup -> + file:rename(KnownHosts, B); + restore -> + file:delete(KnownHosts), + file:rename(B, KnownHosts) + end. + + +get_user_dir() -> + case os:type() of + {win32, _} -> + [{user_dir, filename:join([os:getenv("HOME"), ".ssh"])}]; + _ -> + [] + end. + + +make_dsa_cert_files(Config) -> + make_dsa_cert_files("", Config). + +make_dsa_cert_files(RoleStr, Config) -> + + CaInfo = {CaCert, _} = make_cert([{key, dsa}]), + {Cert, CertKey} = make_cert([{key, dsa}, {issuer, CaInfo}]), + CaCertFile = filename:join([?config(data_dir, Config), + RoleStr, "dsa_cacerts.pem"]), + CertFile = filename:join([?config(data_dir, Config), + RoleStr, "dsa_cert.pem"]), + KeyFile = filename:join([?config(data_dir, Config), + RoleStr, "dsa_key.pem"]), + + der_to_pem(CaCertFile, [{'Certificate', CaCert, not_encrypted}]), + der_to_pem(CertFile, [{'Certificate', Cert, not_encrypted}]), + der_to_pem(KeyFile, [CertKey]), + {CaCertFile, CertFile, KeyFile}. + +make_dsa_files(Config) -> + make_dsa_files(Config, rfc4716_public_key). +make_dsa_files(Config, Type) -> + {DSA, EncodedKey} = ssh_test_lib:gen_dsa(128, 20), + PKey = DSA#'DSAPrivateKey'.y, + P = DSA#'DSAPrivateKey'.p, + Q = DSA#'DSAPrivateKey'.q, + G = DSA#'DSAPrivateKey'.g, + Dss = #'Dss-Parms'{p=P, q=Q, g=G}, + {ok, Hostname} = inet:gethostname(), + {ok, {A, B, C, D}} = inet:getaddr(Hostname, inet), + IP = lists:concat([A, ".", B, ".", C, ".", D]), + Attributes = [], % Could be [{comment,"user@" ++ Hostname}], + HostNames = [{hostnames,[IP, IP]}], + PublicKey = [{{PKey, Dss}, Attributes}], + KnownHosts = [{{PKey, Dss}, HostNames}], + + KnownHostsEnc = public_key:ssh_encode(KnownHosts, known_hosts), + KnownHosts = public_key:ssh_decode(KnownHostsEnc, known_hosts), + + PublicKeyEnc = public_key:ssh_encode(PublicKey, Type), +% PublicKey = public_key:ssh_decode(PublicKeyEnc, Type), + + SystemTmpDir = ?config(data_dir, Config), + filelib:ensure_dir(SystemTmpDir), + file:make_dir(SystemTmpDir), + + DSAFile = filename:join(SystemTmpDir, "ssh_host_dsa_key.pub"), + file:delete(DSAFile), + + DSAPrivateFile = filename:join(SystemTmpDir, "ssh_host_dsa_key"), + file:delete(DSAPrivateFile), + + KHFile = filename:join(SystemTmpDir, "known_hosts"), + file:delete(KHFile), + + PemBin = public_key:pem_encode([EncodedKey]), + + file:write_file(DSAFile, PublicKeyEnc), + file:write_file(KHFile, KnownHostsEnc), + file:write_file(DSAPrivateFile, PemBin), + ok. + +%%-------------------------------------------------------------------- +%% Create and return a der encoded certificate +%% Option Default +%% ------------------------------------------------------- +%% digest sha1 +%% validity {date(), date() + week()} +%% version 3 +%% subject [] list of the following content +%% {name, Name} +%% {email, Email} +%% {city, City} +%% {state, State} +%% {org, Org} +%% {org_unit, OrgUnit} +%% {country, Country} +%% {serial, Serial} +%% {title, Title} +%% {dnQualifer, DnQ} +%% issuer = {Issuer, IssuerKey} true (i.e. a ca cert is created) +%% (obs IssuerKey migth be {Key, Password} +%% key = KeyFile|KeyBin|rsa|dsa Subject PublicKey rsa or dsa generates key +%% +%% +%% (OBS: The generated keys are for testing only) +%% make_cert([{::atom(), ::term()}]) -> {Cert::binary(), Key::binary()} +%%-------------------------------------------------------------------- +make_cert(Opts) -> + SubjectPrivateKey = get_key(Opts), + {TBSCert, IssuerKey} = make_tbs(SubjectPrivateKey, Opts), + Cert = public_key:pkix_sign(TBSCert, IssuerKey), + true = verify_signature(Cert, IssuerKey, undef), %% verify that the keys where ok + {Cert, encode_key(SubjectPrivateKey)}. + +%%-------------------------------------------------------------------- +%% Writes cert files in Dir with FileName and FileName ++ Suffix +%% write_cert(::string(), ::string(), {Cert,Key}) -> ok +%%-------------------------------------------------------------------- +write_cert(Dir, FileName, Suffix, {Cert, Key = {_,_,not_encrypted}}) when is_binary(Cert) -> + ok = der_to_pem(filename:join(Dir, FileName), + [{'Certificate', Cert, not_encrypted}]), + ok = der_to_pem(filename:join(Dir, FileName ++ Suffix), [Key]). + +%%-------------------------------------------------------------------- +%% Creates a rsa key (OBS: for testing only) +%% the size are in bytes +%% gen_rsa(::integer()) -> {::atom(), ::binary(), ::opaque()} +%%-------------------------------------------------------------------- +gen_rsa(Size) when is_integer(Size) -> + Key = gen_rsa2(Size), + {Key, encode_key(Key)}. + +%%-------------------------------------------------------------------- +%% Creates a dsa key (OBS: for testing only) +%% the sizes are in bytes +%% gen_dsa(::integer()) -> {::atom(), ::binary(), ::opaque()} +%%-------------------------------------------------------------------- +gen_dsa(LSize,NSize) when is_integer(LSize), is_integer(NSize) -> + Key = gen_dsa2(LSize, NSize), + {Key, encode_key(Key)}. + +%%-------------------------------------------------------------------- +%% Verifies cert signatures +%% verify_signature(::binary(), ::tuple()) -> ::boolean() +%%-------------------------------------------------------------------- +verify_signature(DerEncodedCert, DerKey, _KeyParams) -> + Key = decode_key(DerKey), + case Key of + #'RSAPrivateKey'{modulus=Mod, publicExponent=Exp} -> + public_key:pkix_verify(DerEncodedCert, + #'RSAPublicKey'{modulus=Mod, publicExponent=Exp}); + #'DSAPrivateKey'{p=P, q=Q, g=G, y=Y} -> + public_key:pkix_verify(DerEncodedCert, {Y, #'Dss-Parms'{p=P, q=Q, g=G}}) + end. + +%%%%%%%%%%%%%%%%%%%%%%%%% Implementation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +get_key(Opts) -> + case proplists:get_value(key, Opts) of + undefined -> make_key(rsa, Opts); + rsa -> make_key(rsa, Opts); + dsa -> make_key(dsa, Opts); + Key -> + Password = proplists:get_value(password, Opts, no_passwd), + decode_key(Key, Password) + end. + +decode_key({Key, Pw}) -> + decode_key(Key, Pw); +decode_key(Key) -> + decode_key(Key, no_passwd). + + +decode_key(#'RSAPublicKey'{} = Key,_) -> + Key; +decode_key(#'RSAPrivateKey'{} = Key,_) -> + Key; +decode_key(#'DSAPrivateKey'{} = Key,_) -> + Key; +decode_key(PemEntry = {_,_,_}, Pw) -> + public_key:pem_entry_decode(PemEntry, Pw); +decode_key(PemBin, Pw) -> + [KeyInfo] = public_key:pem_decode(PemBin), + decode_key(KeyInfo, Pw). + +encode_key(Key = #'RSAPrivateKey'{}) -> + {ok, Der} = 'OTP-PUB-KEY':encode('RSAPrivateKey', Key), + {'RSAPrivateKey', list_to_binary(Der), not_encrypted}; +encode_key(Key = #'DSAPrivateKey'{}) -> + {ok, Der} = 'OTP-PUB-KEY':encode('DSAPrivateKey', Key), + {'DSAPrivateKey', list_to_binary(Der), not_encrypted}. + +make_tbs(SubjectKey, Opts) -> + Version = list_to_atom("v"++integer_to_list(proplists:get_value(version, Opts, 3))), + + IssuerProp = proplists:get_value(issuer, Opts, true), + {Issuer, IssuerKey} = issuer(IssuerProp, Opts, SubjectKey), + + {Algo, Parameters} = sign_algorithm(IssuerKey, Opts), + + SignAlgo = #'SignatureAlgorithm'{algorithm = Algo, + parameters = Parameters}, + Subject = case IssuerProp of + true -> %% Is a Root Ca + Issuer; + _ -> + subject(proplists:get_value(subject, Opts),false) + end, + + {#'OTPTBSCertificate'{serialNumber = trunc(random:uniform()*100000000)*10000 + 1, + signature = SignAlgo, + issuer = Issuer, + validity = validity(Opts), + subject = Subject, + subjectPublicKeyInfo = publickey(SubjectKey), + version = Version, + extensions = extensions(Opts) + }, IssuerKey}. + +issuer(true, Opts, SubjectKey) -> + %% Self signed + {subject(proplists:get_value(subject, Opts), true), SubjectKey}; +issuer({Issuer, IssuerKey}, _Opts, _SubjectKey) when is_binary(Issuer) -> + {issuer_der(Issuer), decode_key(IssuerKey)}; +issuer({File, IssuerKey}, _Opts, _SubjectKey) when is_list(File) -> + {ok, [{cert, Cert, _}|_]} = pem_to_der(File), + {issuer_der(Cert), decode_key(IssuerKey)}. + +issuer_der(Issuer) -> + Decoded = public_key:pkix_decode_cert(Issuer, otp), + #'OTPCertificate'{tbsCertificate=Tbs} = Decoded, + #'OTPTBSCertificate'{subject=Subject} = Tbs, + Subject. + +subject(undefined, IsRootCA) -> + User = if IsRootCA -> "RootCA"; true -> os:getenv("USER") end, + Opts = [{email, User ++ "@erlang.org"}, + {name, User}, + {city, "Stockholm"}, + {country, "SE"}, + {org, "erlang"}, + {org_unit, "testing dep"}], + subject(Opts); +subject(Opts, _) -> + subject(Opts). + +subject(SubjectOpts) when is_list(SubjectOpts) -> + Encode = fun(Opt) -> + {Type,Value} = subject_enc(Opt), + [#'AttributeTypeAndValue'{type=Type, value=Value}] + end, + {rdnSequence, [Encode(Opt) || Opt <- SubjectOpts]}. + +%% Fill in the blanks +subject_enc({name, Name}) -> {?'id-at-commonName', {printableString, Name}}; +subject_enc({email, Email}) -> {?'id-emailAddress', Email}; +subject_enc({city, City}) -> {?'id-at-localityName', {printableString, City}}; +subject_enc({state, State}) -> {?'id-at-stateOrProvinceName', {printableString, State}}; +subject_enc({org, Org}) -> {?'id-at-organizationName', {printableString, Org}}; +subject_enc({org_unit, OrgUnit}) -> {?'id-at-organizationalUnitName', {printableString, OrgUnit}}; +subject_enc({country, Country}) -> {?'id-at-countryName', Country}; +subject_enc({serial, Serial}) -> {?'id-at-serialNumber', Serial}; +subject_enc({title, Title}) -> {?'id-at-title', {printableString, Title}}; +subject_enc({dnQualifer, DnQ}) -> {?'id-at-dnQualifier', DnQ}; +subject_enc(Other) -> Other. + + +extensions(Opts) -> + case proplists:get_value(extensions, Opts, []) of + false -> + asn1_NOVALUE; + Exts -> + lists:flatten([extension(Ext) || Ext <- default_extensions(Exts)]) + end. + +default_extensions(Exts) -> + Def = [{key_usage,undefined}, + {subject_altname, undefined}, + {issuer_altname, undefined}, + {basic_constraints, default}, + {name_constraints, undefined}, + {policy_constraints, undefined}, + {ext_key_usage, undefined}, + {inhibit_any, undefined}, + {auth_key_id, undefined}, + {subject_key_id, undefined}, + {policy_mapping, undefined}], + Filter = fun({Key, _}, D) -> lists:keydelete(Key, 1, D) end, + Exts ++ lists:foldl(Filter, Def, Exts). + +extension({_, undefined}) -> []; +extension({basic_constraints, Data}) -> + case Data of + default -> + #'Extension'{extnID = ?'id-ce-basicConstraints', + extnValue = #'BasicConstraints'{cA=true}, + critical=true}; + false -> + []; + Len when is_integer(Len) -> + #'Extension'{extnID = ?'id-ce-basicConstraints', + extnValue = #'BasicConstraints'{cA=true, pathLenConstraint=Len}, + critical=true}; + _ -> + #'Extension'{extnID = ?'id-ce-basicConstraints', + extnValue = Data} + end; +extension({Id, Data, Critical}) -> + #'Extension'{extnID = Id, extnValue = Data, critical = Critical}. + + +publickey(#'RSAPrivateKey'{modulus=N, publicExponent=E}) -> + Public = #'RSAPublicKey'{modulus=N, publicExponent=E}, + Algo = #'PublicKeyAlgorithm'{algorithm= ?rsaEncryption, parameters='NULL'}, + #'OTPSubjectPublicKeyInfo'{algorithm = Algo, + subjectPublicKey = Public}; +publickey(#'DSAPrivateKey'{p=P, q=Q, g=G, y=Y}) -> + Algo = #'PublicKeyAlgorithm'{algorithm= ?'id-dsa', + parameters={params, #'Dss-Parms'{p=P, q=Q, g=G}}}, + #'OTPSubjectPublicKeyInfo'{algorithm = Algo, subjectPublicKey = Y}. + +validity(Opts) -> + DefFrom0 = calendar:gregorian_days_to_date(calendar:date_to_gregorian_days(date())-1), + DefTo0 = calendar:gregorian_days_to_date(calendar:date_to_gregorian_days(date())+7), + {DefFrom, DefTo} = proplists:get_value(validity, Opts, {DefFrom0, DefTo0}), + Format = fun({Y,M,D}) -> lists:flatten(io_lib:format("~w~2..0w~2..0w000000Z",[Y,M,D])) end, + #'Validity'{notBefore={generalTime, Format(DefFrom)}, + notAfter ={generalTime, Format(DefTo)}}. + +sign_algorithm(#'RSAPrivateKey'{}, Opts) -> + Type = case proplists:get_value(digest, Opts, sha1) of + sha1 -> ?'sha1WithRSAEncryption'; + sha512 -> ?'sha512WithRSAEncryption'; + sha384 -> ?'sha384WithRSAEncryption'; + sha256 -> ?'sha256WithRSAEncryption'; + md5 -> ?'md5WithRSAEncryption'; + md2 -> ?'md2WithRSAEncryption' + end, + {Type, 'NULL'}; +sign_algorithm(#'DSAPrivateKey'{p=P, q=Q, g=G}, _Opts) -> + {?'id-dsa-with-sha1', {params,#'Dss-Parms'{p=P, q=Q, g=G}}}. + +make_key(rsa, _Opts) -> + %% (OBS: for testing only) + gen_rsa2(64); +make_key(dsa, _Opts) -> + gen_dsa2(128, 20). %% Bytes i.e. {1024, 160} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% RSA key generation (OBS: for testing only) +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +-define(SMALL_PRIMES, [65537,97,89,83,79,73,71,67,61,59,53, + 47,43,41,37,31,29,23,19,17,13,11,7,5,3]). + +gen_rsa2(Size) -> + P = prime(Size), + Q = prime(Size), + N = P*Q, + Tot = (P - 1) * (Q - 1), + [E|_] = lists:dropwhile(fun(Candidate) -> (Tot rem Candidate) == 0 end, ?SMALL_PRIMES), + {D1,D2} = extended_gcd(E, Tot), + D = erlang:max(D1,D2), + case D < E of + true -> + gen_rsa2(Size); + false -> + {Co1,Co2} = extended_gcd(Q, P), + Co = erlang:max(Co1,Co2), + #'RSAPrivateKey'{version = 'two-prime', + modulus = N, + publicExponent = E, + privateExponent = D, + prime1 = P, + prime2 = Q, + exponent1 = D rem (P-1), + exponent2 = D rem (Q-1), + coefficient = Co + } + end. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% DSA key generation (OBS: for testing only) +%% See http://en.wikipedia.org/wiki/Digital_Signature_Algorithm +%% and the fips_186-3.pdf +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +gen_dsa2(LSize, NSize) -> + Q = prime(NSize), %% Choose N-bit prime Q + X0 = prime(LSize), + P0 = prime((LSize div 2) +1), + + %% Choose L-bit prime modulus P such that p-1 is a multiple of q. + case dsa_search(X0 div (2*Q*P0), P0, Q, 1000) of + error -> + gen_dsa2(LSize, NSize); + P -> + G = crypto:mod_exp(2, (P-1) div Q, P), % Choose G a number whose multiplicative order modulo p is q. + %% such that This may be done by setting g = h^(p-1)/q mod p, commonly h=2 is used. + + X = prime(20), %% Choose x by some random method, where 0 < x < q. + Y = crypto:mod_exp(G, X, P), %% Calculate y = g^x mod p. + + #'DSAPrivateKey'{version=0, p=P, q=Q, g=G, y=Y, x=X} + end. + +%% See fips_186-3.pdf +dsa_search(T, P0, Q, Iter) when Iter > 0 -> + P = 2*T*Q*P0 + 1, + case is_prime(crypto:mpint(P), 50) of + true -> P; + false -> dsa_search(T+1, P0, Q, Iter-1) + end; +dsa_search(_,_,_,_) -> + error. + + +%%%%%%% Crypto Math %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +prime(ByteSize) -> + Rand = odd_rand(ByteSize), + crypto:erlint(prime_odd(Rand, 0)). + +prime_odd(Rand, N) -> + case is_prime(Rand, 50) of + true -> + Rand; + false -> + NotPrime = crypto:erlint(Rand), + prime_odd(crypto:mpint(NotPrime+2), N+1) + end. + +%% see http://en.wikipedia.org/wiki/Fermat_primality_test +is_prime(_, 0) -> true; +is_prime(Candidate, Test) -> + CoPrime = odd_rand(<<0,0,0,4, 10000:32>>, Candidate), + case crypto:mod_exp(CoPrime, Candidate, Candidate) of + CoPrime -> is_prime(Candidate, Test-1); + _ -> false + end. + +odd_rand(Size) -> + Min = 1 bsl (Size*8-1), + Max = (1 bsl (Size*8))-1, + odd_rand(crypto:mpint(Min), crypto:mpint(Max)). + +odd_rand(Min,Max) -> + Rand = <<Sz:32, _/binary>> = crypto:rand_uniform(Min,Max), + BitSkip = (Sz+4)*8-1, + case Rand of + Odd = <<_:BitSkip, 1:1>> -> Odd; + Even = <<_:BitSkip, 0:1>> -> + crypto:mpint(crypto:erlint(Even)+1) + end. + +extended_gcd(A, B) -> + case A rem B of + 0 -> + {0, 1}; + N -> + {X, Y} = extended_gcd(B, N), + {Y, X-Y*(A div B)} + end. + +pem_to_der(File) -> + {ok, PemBin} = file:read_file(File), + public_key:pem_decode(PemBin). + +der_to_pem(File, Entries) -> + PemBin = public_key:pem_encode(Entries), + file:write_file(File, PemBin). |