From 64724376b145aced17c9d518e5c41f25a2d85cc9 Mon Sep 17 00:00:00 2001 From: Matt Campbell Date: Fri, 5 Feb 2016 14:43:18 -0600 Subject: ssl: verify cert signature against original cert binary When searching for a certificate's issuer in the `CertDB`, verify the signature against the original DER certificate from the handshake instead of a re-encoding of the parsed certificate. This avoids false negatives due to differences between DER encoding implementations of OTP and other platforms. --- lib/ssl/src/ssl_certificate.erl | 22 ++++----- lib/ssl/test/ssl_certificate_verify_SUITE.erl | 65 ++++++++++++++++++++++++++- 2 files changed, 75 insertions(+), 12 deletions(-) diff --git a/lib/ssl/src/ssl_certificate.erl b/lib/ssl/src/ssl_certificate.erl index 4658e76ab1..e9dc5764a3 100644 --- a/lib/ssl/src/ssl_certificate.erl +++ b/lib/ssl/src/ssl_certificate.erl @@ -56,15 +56,15 @@ %% errors. Returns {RootCert, Path, VerifyErrors} %%-------------------------------------------------------------------- trusted_cert_and_path(CertChain, CertDbHandle, CertDbRef, PartialChainHandler) -> - Path = [Cert | _] = lists:reverse(CertChain), - OtpCert = public_key:pkix_decode_cert(Cert, otp), + Path = [BinCert | _] = lists:reverse(CertChain), + OtpCert = public_key:pkix_decode_cert(BinCert, otp), SignedAndIssuerID = case public_key:pkix_is_self_signed(OtpCert) of true -> {ok, IssuerId} = public_key:pkix_issuer_id(OtpCert, self), {self, IssuerId}; false -> - other_issuer(OtpCert, CertDbHandle) + other_issuer(OtpCert, BinCert, CertDbHandle) end, case SignedAndIssuerID of @@ -187,7 +187,7 @@ public_key_type(?'id-ecPublicKey') -> %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- -certificate_chain(OtpCert, _Cert, CertDbHandle, CertsDbRef, Chain) -> +certificate_chain(OtpCert, BinCert, CertDbHandle, CertsDbRef, Chain) -> IssuerAndSelfSigned = case public_key:pkix_is_self_signed(OtpCert) of true -> @@ -200,7 +200,7 @@ certificate_chain(OtpCert, _Cert, CertDbHandle, CertsDbRef, Chain) -> {_, true = SelfSigned} -> certificate_chain(CertDbHandle, CertsDbRef, Chain, ignore, ignore, SelfSigned); {{error, issuer_not_found}, SelfSigned} -> - case find_issuer(OtpCert, CertDbHandle) of + case find_issuer(OtpCert, BinCert, CertDbHandle) of {ok, {SerialNr, Issuer}} -> certificate_chain(CertDbHandle, CertsDbRef, Chain, SerialNr, Issuer, SelfSigned); @@ -232,12 +232,12 @@ certificate_chain(CertDbHandle, CertsDbRef, Chain, SerialNr, Issuer, _SelfSigned {ok, undefined, lists:reverse(Chain)} end. -find_issuer(OtpCert, CertDbHandle) -> +find_issuer(OtpCert, BinCert, CertDbHandle) -> IsIssuerFun = fun({_Key, {_Der, #'OTPCertificate'{} = ErlCertCandidate}}, Acc) -> case public_key:pkix_is_issuer(OtpCert, ErlCertCandidate) of true -> - case verify_cert_signer(OtpCert, ErlCertCandidate#'OTPCertificate'.tbsCertificate) of + case verify_cert_signer(BinCert, ErlCertCandidate#'OTPCertificate'.tbsCertificate) of true -> throw(public_key:pkix_issuer_id(ErlCertCandidate, self)); false -> @@ -265,9 +265,9 @@ is_valid_extkey_usage(KeyUse, server) -> %% Server wants to verify client is_valid_key_usage(KeyUse, ?'id-kp-clientAuth'). -verify_cert_signer(OtpCert, SignerTBSCert) -> +verify_cert_signer(BinCert, SignerTBSCert) -> PublicKey = public_key(SignerTBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo), - public_key:pkix_verify(public_key:pkix_encode('OTPCertificate', OtpCert, otp), PublicKey). + public_key:pkix_verify(BinCert, PublicKey). public_key(#'OTPSubjectPublicKeyInfo'{algorithm = #'PublicKeyAlgorithm'{algorithm = ?'id-ecPublicKey', parameters = Params}, @@ -281,12 +281,12 @@ public_key(#'OTPSubjectPublicKeyInfo'{algorithm = #'PublicKeyAlgorithm'{algorith subjectPublicKey = Key}) -> {Key, Params}. -other_issuer(OtpCert, CertDbHandle) -> +other_issuer(OtpCert, BinCert, CertDbHandle) -> case public_key:pkix_issuer_id(OtpCert, other) of {ok, IssuerId} -> {other, IssuerId}; {error, issuer_not_found} -> - case find_issuer(OtpCert, CertDbHandle) of + case find_issuer(OtpCert, BinCert, CertDbHandle) of {ok, IssuerId} -> {other, IssuerId}; Other -> diff --git a/lib/ssl/test/ssl_certificate_verify_SUITE.erl b/lib/ssl/test/ssl_certificate_verify_SUITE.erl index 5940a86a7f..968ef30791 100644 --- a/lib/ssl/test/ssl_certificate_verify_SUITE.erl +++ b/lib/ssl/test/ssl_certificate_verify_SUITE.erl @@ -75,7 +75,8 @@ error_handling_tests()-> unknown_server_ca_accept_verify_none, unknown_server_ca_accept_verify_peer, unknown_server_ca_accept_backwardscompatibility, - no_authority_key_identifier]. + no_authority_key_identifier, + no_authority_key_identifier_and_nonstandard_encoding]. init_per_suite(Config0) -> catch crypto:stop(), @@ -850,6 +851,68 @@ delete_authority_key_extension([Head | Rest], Acc) -> %%-------------------------------------------------------------------- +no_authority_key_identifier_and_nonstandard_encoding() -> + [{doc, "Test cert with nonstandard encoding that does not have" + " authorityKeyIdentifier extension but are present in trusted certs db."}]. + +no_authority_key_identifier_and_nonstandard_encoding(Config) when is_list(Config) -> + ClientOpts = ?config(client_verification_opts, Config), + ServerOpts = ?config(server_verification_opts, Config), + PrivDir = ?config(priv_dir, Config), + + KeyFile = filename:join(PrivDir, "otpCA/private/key.pem"), + [KeyEntry] = ssl_test_lib:pem_to_der(KeyFile), + Key = ssl_test_lib:public_key(public_key:pem_entry_decode(KeyEntry)), + + CertFile = proplists:get_value(certfile, ServerOpts), + NewCertFile = filename:join(PrivDir, "server/new_cert.pem"), + [{'Certificate', DerCert, _}] = ssl_test_lib:pem_to_der(CertFile), + ServerCert = public_key:pkix_decode_cert(DerCert, plain), + ServerTbsCert = ServerCert#'Certificate'.tbsCertificate, + Extensions0 = ServerTbsCert#'TBSCertificate'.extensions, + %% need to remove authorityKeyIdentifier extension to cause DB lookup by signature + Extensions = delete_authority_key_extension(Extensions0, []), + NewExtensions = replace_key_usage_extension(Extensions, []), + NewServerTbsCert = ServerTbsCert#'TBSCertificate'{extensions = NewExtensions}, + + ct:log("Extensions ~p~n, NewExtensions: ~p~n", [Extensions, NewExtensions]), + + TbsDer = public_key:pkix_encode('TBSCertificate', NewServerTbsCert, plain), + Sig = public_key:sign(TbsDer, md5, Key), + NewServerCert = ServerCert#'Certificate'{tbsCertificate = NewServerTbsCert, signature = Sig}, + NewDerCert = public_key:pkix_encode('Certificate', NewServerCert, plain), + ssl_test_lib:der_to_pem(NewCertFile, [{'Certificate', NewDerCert, not_encrypted}]), + NewServerOpts = [{certfile, NewCertFile} | proplists:delete(certfile, ServerOpts)], + + {ClientNode, ServerNode, Hostname} = ssl_test_lib:run_where(Config), + + Server = ssl_test_lib:start_server([{node, ServerNode}, {port, 0}, + {from, self()}, + {mfa, {ssl_test_lib, + send_recv_result_active, []}}, + {options, [{active, true} | NewServerOpts]}]), + Port = ssl_test_lib:inet_port(Server), + Client = ssl_test_lib:start_client([{node, ClientNode}, {port, Port}, + {host, Hostname}, + {from, self()}, + {mfa, {ssl_test_lib, + send_recv_result_active, []}}, + {options, [{verify, verify_peer} | ClientOpts]}]), + ssl_test_lib:check_result(Server, ok, Client, ok), + ssl_test_lib:close(Server), + ssl_test_lib:close(Client). + +replace_key_usage_extension([], Acc) -> + lists:reverse(Acc); +replace_key_usage_extension([#'Extension'{extnID = ?'id-ce-keyUsage'} = E | Rest], Acc) -> + %% A nonstandard DER encoding of [digitalSignature, keyEncipherment] + Val = <<3, 2, 0, 16#A0>>, + replace_key_usage_extension(Rest, [E#'Extension'{extnValue = Val} | Acc]); +replace_key_usage_extension([Head | Rest], Acc) -> + replace_key_usage_extension(Rest, [Head | Acc]). + +%%-------------------------------------------------------------------- + invalid_signature_server() -> [{doc,"Test client with invalid signature"}]. -- cgit v1.2.3