From eb3f705c39e022bf3d07c27d6e5b8ddfed638992 Mon Sep 17 00:00:00 2001 From: Linus Nordberg Date: Mon, 27 Feb 2017 14:48:08 +0100 Subject: Look for root last in list, not anywhere in list. Even if verify_chain() should not return a root cert that is not last in the chain, the code is now less confusing to read. Also, rename normalise_chain/3 to verify_chain to reflect what it actually does. --- src/x509.erl | 72 ++++++++++++++++++++++++++++++------------------------------ 1 file changed, 36 insertions(+), 36 deletions(-) (limited to 'src') diff --git a/src/x509.erl b/src/x509.erl index 0b32c4e..f44e36f 100644 --- a/src/x509.erl +++ b/src/x509.erl @@ -21,14 +21,14 @@ -spec normalise_chain([binary()], [binary()]) -> {ok, [binary()]} | {error, reason()}. normalise_chain(AcceptableRootCerts, CertChain) -> - case normalise_chain(AcceptableRootCerts, CertChain, ?MAX_CHAIN_LENGTH) of + case verify_chain(AcceptableRootCerts, CertChain, ?MAX_CHAIN_LENGTH) of {false, Reason} -> {error, Reason}; {true, Root} -> - case lists:member(Root, CertChain) of - true -> + case lists:last(CertChain) of + Root -> {ok, CertChain}; - false -> + _ -> {ok, CertChain ++ [Root]} end end. @@ -68,8 +68,8 @@ detox(LeafDer, ChainDer) -> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% Private functions. --spec normalise_chain([binary()], [binary()], integer()) -> - {false, reason()} | {true, [binary()]}. +-spec verify_chain([binary()], [binary()], integer()) -> + {false, reason()} | {true, [binary()]}. %% @doc Verify that the leaf cert or precert has a valid chain back to %% an acceptable root cert. The order of certificates in the second %% argument is: leaf cert in head, chain in tail. Order of certs in first @@ -77,10 +77,10 @@ detox(LeafDer, ChainDer) -> %% %% Return {false, Reason} or {true, Root} where Root is a CA cert from %% AcceptableRootCerts signing the root of the chain. -normalise_chain(_, _, MaxChainLength) when MaxChainLength =< 0 -> +verify_chain(_, _, MaxChainLength) when MaxChainLength =< 0 -> %% Chain too long. {false, chain_too_long}; -normalise_chain(AcceptableRootCerts, [TopCert], MaxChainLength) -> +verify_chain(AcceptableRootCerts, [TopCert], MaxChainLength) -> %% Check root of chain. case lists:member(TopCert, AcceptableRootCerts) of true -> @@ -96,9 +96,9 @@ normalise_chain(AcceptableRootCerts, [TopCert], MaxChainLength) -> Root -> {true, Root} end end; -normalise_chain(AcceptableRootCerts, [Cert|Rest], MaxChainLength) -> +verify_chain(AcceptableRootCerts, [Cert|Rest], MaxChainLength) -> case signed_by_p(Cert, hd(Rest)) of - true -> normalise_chain(AcceptableRootCerts, Rest, MaxChainLength - 1); + true -> verify_chain(AcceptableRootCerts, Rest, MaxChainLength - 1); false -> {false, signature_mismatch} end. @@ -414,21 +414,21 @@ valid_cert_test_() -> %% #'OTPCertificate'{}. The error is %% {invalid_choice_tag,{22,<<"US">>}}}} in %% 'OTP-PUB-KEY':Func('OTP-X520countryname', Value0). - ?_assertMatch({true, _}, normalise_chain(nth(1, Chains), - nth(1, Chains), 10)), + ?_assertMatch({true, _}, verify_chain(nth(1, Chains), + nth(1, Chains), 10)), %% Self-signed so fail. ?_assertMatch({false, root_unknown}, - normalise_chain(KnownRoots, - nth(2, Chains), 10)), + verify_chain(KnownRoots, + nth(2, Chains), 10)), %% Leaf signed by known CA, pass. - ?_assertMatch({true, _}, normalise_chain(KnownRoots, - nth(3, Chains), 10)), + ?_assertMatch({true, _}, verify_chain(KnownRoots, + nth(3, Chains), 10)), %% Proper 3-depth chain with root in KnownRoots, pass. %% Bug CATLFISH-19 --> [info] rejecting "3ee62cb678014c14d22ebf96f44cc899adea72f1": chain_broken %% leaf sha1: 3ee62cb678014c14d22ebf96f44cc899adea72f1 %% leaf Subject: C=KR, O=Government of Korea, OU=Group of Server, OU=\xEA\xB5\x90\xEC\x9C\xA1\xEA\xB3\xBC\xED\x95\x99\xEA\xB8\xB0\xEC\x88\xA0\xEB\xB6\x80, CN=www.berea.ac.kr, CN=haksa.bits.ac.kr - ?_assertMatch({true, _}, normalise_chain(KnownRoots, - nth(4, Chains), 3)), + ?_assertMatch({true, _}, verify_chain(KnownRoots, + nth(4, Chains), 3)), %% Verify against self, pass. %% Bug CATLFISH-??, can't handle issuer keytype ECPoint. %% Issuer sha1: 6969562e4080f424a1e7199f14baf3ee58ab6abb @@ -442,31 +442,31 @@ valid_cert_test_() -> %% Supposedly problematic chains from Google Aviator, fatal. %% 00459972: asn1: syntax error: sequence truncated - ?_assertMatch({true, _}, normalise_chain(nth(7, Chains), - nth(7, Chains), 10)), + ?_assertMatch({true, _}, verify_chain(nth(7, Chains), + nth(7, Chains), 10)), %% 1402673: x509: RSA modulus is not a positive number - ?_assertMatch({true, _}, normalise_chain(nth(8, Chains), - nth(8, Chains), 10)), + ?_assertMatch({true, _}, verify_chain(nth(8, Chains), + nth(8, Chains), 10)), %% 1345105: asn1: syntax error: IA5String contains invalid character - ?_assertMatch({true, _}, normalise_chain(nth(9, Chains), - nth(9, Chains), 10)), + ?_assertMatch({true, _}, verify_chain(nth(9, Chains), + nth(9, Chains), 10)), %% 1557693: asn1: structure error: integer too large - ?_assertMatch({true, _}, normalise_chain(nth(10, Chains), - nth(10, Chains), 10)), + ?_assertMatch({true, _}, verify_chain(nth(10, Chains), + nth(10, Chains), 10)), %% Supposedly problematic chains from Google Aviator, non-fatal. %% 16800: x509: negative serial number %% a.pem - ?_assertMatch({true, _}, normalise_chain(nth(11, Chains), - nth(11, Chains), 10)), + ?_assertMatch({true, _}, verify_chain(nth(11, Chains), + nth(11, Chains), 10)), %% 22487: x509: unhandled critical extension ([2 5 29 32]) %% b.pem - ?_assertMatch({true, _}, normalise_chain(nth(12, Chains), - nth(12, Chains), 10)), + ?_assertMatch({true, _}, verify_chain(nth(12, Chains), + nth(12, Chains), 10)), %% 5198: x509: certificate contained IP address of length 8 %% c.pem - ?_assertMatch({true, _}, normalise_chain(nth(13, Chains), - nth(13, Chains), 10)) + ?_assertMatch({true, _}, verify_chain(nth(13, Chains), + nth(13, Chains), 10)) ] end}. chain_test_() -> @@ -480,19 +480,19 @@ chain_test(C0, C1) -> %% Root not in chain but in trust store. ?_assertEqual({ok, [C0, C1]}, normalise_chain([C1], [C0])), %% Same, but chain too long. - ?_assertEqual({false, chain_too_long}, normalise_chain([C1], [C0], 1)), + ?_assertEqual({false, chain_too_long}, verify_chain([C1], [C0], 1)), %% Root in chain and in trust store. ?_assertEqual({ok, [C0, C1]}, normalise_chain([C1], [C0, C1])), %% Same, but chain too long. - ?_assertEqual({false, chain_too_long}, normalise_chain([C1], [C0, C1], 1)), + ?_assertEqual({false, chain_too_long}, verify_chain([C1], [C0, C1], 1)), %% Root not in trust store. ?_assertEqual({error, root_unknown}, normalise_chain([], [C0, C1])), %% Selfsigned. Actually OK. ?_assertEqual({ok, [C0]}, normalise_chain([C0], [C0])), %% Same, still OK. - ?_assertEqual({true, C0}, normalise_chain([C0], [C0], 1)), + ?_assertEqual({true, C0}, verify_chain([C0], [C0], 1)), %% Max chain length 0 is not OK. - ?_assertEqual({false, chain_too_long}, normalise_chain([C0], [C0], 0)) + ?_assertEqual({false, chain_too_long}, verify_chain([C0], [C0], 0)) ]. %%-spec read_certs(file:filename()) -> [string:string()]. -- cgit v1.1