From b0c245e8132bb13171e277b1af59c0cec00c9459 Mon Sep 17 00:00:00 2001 From: Hans Nilsson Date: Mon, 19 Dec 2016 18:26:01 +0100 Subject: public_key: pkix_verify_hostname (RFC 6125) --- lib/public_key/src/public_key.erl | 164 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 164 insertions(+) (limited to 'lib/public_key/src') diff --git a/lib/public_key/src/public_key.erl b/lib/public_key/src/public_key.erl index 05c09f8996..402f514803 100644 --- a/lib/public_key/src/public_key.erl +++ b/lib/public_key/src/public_key.erl @@ -48,6 +48,7 @@ pkix_issuer_id/2, pkix_normalize_name/1, pkix_path_validation/3, + pkix_verify_hostname/2, pkix_verify_hostname/3, ssh_decode/2, ssh_encode/2, ssh_hostkey_fingerprint/1, ssh_hostkey_fingerprint/2, ssh_curvename2oid/1, oid2ssh_curvename/1, @@ -763,6 +764,76 @@ pkix_crls_validate(OtpCert, DPAndCRLs0, Options) -> pkix_crls_validate(OtpCert, DPAndCRLs, DPAndCRLs, Options, pubkey_crl:init_revokation_state()). +%-------------------------------------------------------------------- +-spec pkix_verify_hostname(Cert :: #'OTPCertificate'{} | binary(), + ReferenceIDs :: [{uri_id | dns_id | oid(), string()}]) -> boolean(). + +-spec pkix_verify_hostname(Cert :: #'OTPCertificate'{} | binary(), + ReferenceIDs :: [{uri_id | dns_id | oid(), string()}], + Options :: proplists:proplist()) -> boolean(). + +%% Description: Validates a hostname to RFC 6125 +%%-------------------------------------------------------------------- +pkix_verify_hostname(Cert, ReferenceIDs) -> + pkix_verify_hostname(Cert, ReferenceIDs, []). + +pkix_verify_hostname(BinCert, ReferenceIDs, Options) when is_binary(BinCert) -> + pkix_verify_hostname(pkix_decode_cert(BinCert,otp), ReferenceIDs, Options); + +pkix_verify_hostname(Cert = #'OTPCertificate'{tbsCertificate = TbsCert}, ReferenceIDs0, Opts) -> + MatchFun = proplists:get_value(match_fun, Opts, undefined), + FailCB = proplists:get_value(fail_callback, Opts, fun(_Cert) -> false end), + FqdnFun = proplists:get_value(fqdn_fun, Opts, fun verify_hostname_extract_fqdn_default/1), + + ReferenceIDs = [{T,to_string(V)} || {T,V} <- ReferenceIDs0], + PresentedIDs = + try lists:keyfind(?'id-ce-subjectAltName', + #'Extension'.extnID, + TbsCert#'OTPTBSCertificate'.extensions) + of + #'Extension'{extnValue = ExtVals} -> + [{T,to_string(V)} || {T,V} <- ExtVals]; + false -> + [] + catch + _:_ -> [] + end, + %% PresentedIDs example: [{dNSName,"ewstest.ericsson.com"}, {dNSName,"www.ericsson.com"}]} + case PresentedIDs of + [] -> + %% Fallback to CN-ids [rfc6125, ch6] + case TbsCert#'OTPTBSCertificate'.subject of + {rdnSequence,RDNseq} -> + PresentedCNs = + [{cn, to_string(V)} + || ATVs <- RDNseq, % RDNseq is list-of-lists + #'AttributeTypeAndValue'{type = ?'id-at-commonName', + value = {_T,V}} <- ATVs + % _T = kind of string (teletexString etc) + ], + %% Example of PresentedCNs: [{cn,"www.ericsson.se"}] + %% match ReferenceIDs to PresentedCNs + verify_hostname_match_loop(verify_hostname_fqnds(ReferenceIDs, FqdnFun), + PresentedCNs, + MatchFun, FailCB, Cert); + + _ -> + false + end; + _ -> + %% match ReferenceIDs to PresentedIDs + case verify_hostname_match_loop(ReferenceIDs, PresentedIDs, + MatchFun, FailCB, Cert) of + false -> + %% Try to extract DNS-IDs from URIs etc + DNS_ReferenceIDs = + [{dns_is,X} || X <- verify_hostname_fqnds(ReferenceIDs, FqdnFun)], + verify_hostname_match_loop(DNS_ReferenceIDs, PresentedIDs, + MatchFun, FailCB, Cert); + true -> + true + end + end. %%-------------------------------------------------------------------- -spec ssh_decode(binary(), public_key | ssh_file()) -> [{public_key(), Attributes::list()}] @@ -1200,3 +1271,96 @@ ascii_to_lower(String) -> end)>> || <> <= iolist_to_binary(String) >>. + +%%%---------------------------------------------------------------- +%%% pkix_verify_hostname help functions +verify_hostname_extract_fqdn_default({dns_id,S}) -> + S; +verify_hostname_extract_fqdn_default({uri_id,URI}) -> + {ok,{https,_,Host,_,_,_}} = http_uri:parse(URI), + Host. + + +verify_hostname_fqnds(L, FqdnFun) -> + [E || E0 <- L, + E <- [try case FqdnFun(E0) of + default -> verify_hostname_extract_fqdn_default(E0); + undefined -> undefined; % will make the "is_list(E)" test fail + Other -> Other + end + catch _:_-> undefined % will make the "is_list(E)" test fail + end], + is_list(E), + E =/= "", + {error,einval} == inet:parse_address(E) + ]. + + +-define(srvName_OID, {1,3,6,1,4,1,434,2,2,1,37,0}). + +verify_hostname_match_default(Ref, Pres) -> + verify_hostname_match_default0(to_lower_ascii(Ref), to_lower_ascii(Pres)). + +verify_hostname_match_default0(FQDN=[_|_], {cn,FQDN}) -> + not lists:member($*, FQDN); +verify_hostname_match_default0(FQDN=[_|_], {cn,Name=[_|_]}) -> + [F1|Fs] = string:tokens(FQDN, "."), + [N1|Ns] = string:tokens(Name, "."), + match_wild(F1,N1) andalso Fs==Ns; +verify_hostname_match_default0({dns_id,R}, {dNSName,P}) -> + R==P; +verify_hostname_match_default0({uri_id,R}, {uniformResourceIdentifier,P}) -> + R==P; +verify_hostname_match_default0({srv_id,R}, {T,P}) when T == srvName ; + T == ?srvName_OID -> + R==P; +verify_hostname_match_default0(_, _) -> + false. + + +match_wild(A, [$*|B]) -> match_wild_suffixes(A, B); +match_wild([C|A], [ C|B]) -> match_wild(A, B); +match_wild([], []) -> true; +match_wild(_, _) -> false. + +%% Match the parts after the only wildcard by comparing them from the end +match_wild_suffixes(A, B) -> match_wild_sfx(lists:reverse(A), lists:reverse(B)). + +match_wild_sfx([$*|_], _) -> false; % Bad name (no wildcards alowed) +match_wild_sfx(_, [$*|_]) -> false; % Bad pattern (no more wildcards alowed) +match_wild_sfx([A|Ar], [A|Br]) -> match_wild_sfx(Ar, Br); +match_wild_sfx(Ar, []) -> not lists:member($*, Ar); % Chk for bad name (= wildcards) +match_wild_sfx(_, _) -> false. + + +verify_hostname_match_loop(Refs0, Pres0, undefined, FailCB, Cert) -> + Pres = lists:map(fun to_lower_ascii/1, Pres0), + Refs = lists:map(fun to_lower_ascii/1, Refs0), + lists:any( + fun(R) -> + lists:any(fun(P) -> + verify_hostname_match_default(R,P) orelse FailCB(Cert) + end, Pres) + end, Refs); +verify_hostname_match_loop(Refs, Pres, MatchFun, FailCB, Cert) -> + lists:any( + fun(R) -> + lists:any(fun(P) -> + (case MatchFun(R,P) of + default -> verify_hostname_match_default(R,P); + Bool -> Bool + end) orelse FailCB(Cert) + end, + Pres) + end, + Refs). + + +to_lower_ascii(S) when is_list(S) -> lists:map(fun to_lower_ascii/1, S); +to_lower_ascii({T,S}) -> {T, to_lower_ascii(S)}; +to_lower_ascii(C) when $A =< C,C =< $Z -> C + ($a-$A); +to_lower_ascii(C) -> C. + +to_string(S) when is_list(S) -> S; +to_string(B) when is_binary(B) -> binary_to_list(B). + -- cgit v1.2.3