From 1c9e0651c4917b63f49d8505dba7e820da8e32d2 Mon Sep 17 00:00:00 2001 From: Ingela Anderton Andin Date: Mon, 1 Sep 2014 15:39:21 +0200 Subject: ssl, public_key: Add new option partial_chain Check that the certificate chain ends with a trusted ROOT CA e.i. a self-signed certificate, but provide an option partial_chain to enable the application to define an intermediat CA as trusted. TLS RFC says: "unknown_ca A valid certificate chain or partial chain was received, but the certificate was not accepted because the CA certificate could not be located or couldn't be matched with a known, trusted CA. This message is always fatal." and also states: "certificate_list This is a sequence (chain) of certificates. The sender's certificate MUST come first in the list. Each following certificate MUST directly certify the one preceding it. Because certificate validation requires that root keys be distributed independently, the self-signed certificate that specifies the root certificate authority MAY be omitted from the chain, under the assumption that the remote end must already possess it in order to validate it in any case." X509 RFC says: "The selection of a trust anchor is a matter of policy: it could be the top CA in a hierarchical PKI, the CA that issued the verifier's own certificate(s), or any other CA in a network PKI. The path validation procedure is the same regardless of the choice of trust anchor. In addition, different applications may rely on different trust anchors, or may accept paths that begin with any of a set of trust anchors." --- lib/ssl/src/ssl.erl | 37 ++++++++++----- lib/ssl/src/ssl_certificate.erl | 100 +++++++++++++++++++++++++--------------- lib/ssl/src/ssl_connection.erl | 4 +- lib/ssl/src/ssl_handshake.erl | 8 ++-- lib/ssl/src/ssl_internal.hrl | 1 + 5 files changed, 97 insertions(+), 53 deletions(-) (limited to 'lib/ssl/src') diff --git a/lib/ssl/src/ssl.erl b/lib/ssl/src/ssl.erl index d741fa63fb..b4bea25942 100644 --- a/lib/ssl/src/ssl.erl +++ b/lib/ssl/src/ssl.erl @@ -569,21 +569,24 @@ handle_options(Opts0, #ssl_options{protocol = Protocol, cacerts = CaCerts0, cacertfile = CaCertFile0} = InheritedSslOpts) -> RecordCB = record_cb(Protocol), CaCerts = handle_option(cacerts, Opts0, CaCerts0), - {Verify, FailIfNoPeerCert, CaCertDefault, VerifyFun} = handle_verify_options(Opts0, CaCerts), + {Verify, FailIfNoPeerCert, CaCertDefault, VerifyFun, PartialChainHanlder} = handle_verify_options(Opts0, CaCerts), CaCertFile = case proplists:get_value(cacertfile, Opts0, CaCertFile0) of undefined -> CaCertDefault; CAFile -> CAFile end, + NewVerifyOpts = InheritedSslOpts#ssl_options{cacerts = CaCerts, cacertfile = CaCertFile, verify = Verify, verify_fun = VerifyFun, + partial_chain = PartialChainHanlder, fail_if_no_peer_cert = FailIfNoPeerCert}, SslOpts1 = lists:foldl(fun(Key, PropList) -> proplists:delete(Key, PropList) - end, Opts0, [cacerts, cacertfile, verify, verify_fun, fail_if_no_peer_cert]), + end, Opts0, [cacerts, cacertfile, verify, verify_fun, partial_chain, + fail_if_no_peer_cert]), case handle_option(versions, SslOpts1, []) of [] -> new_ssl_options(SslOpts1, NewVerifyOpts, RecordCB); @@ -603,10 +606,10 @@ handle_options(Opts0) -> ReuseSessionFun = fun(_, _, _, _) -> true end, CaCerts = handle_option(cacerts, Opts, undefined), - {Verify, FailIfNoPeerCert, CaCertDefault, VerifyFun} = handle_verify_options(Opts, CaCerts), + {Verify, FailIfNoPeerCert, CaCertDefault, VerifyFun, PartialChainHanlder} = + handle_verify_options(Opts, CaCerts), CertFile = handle_option(certfile, Opts, <<>>), - RecordCb = record_cb(Opts), Versions = case handle_option(versions, Opts, []) of @@ -620,6 +623,7 @@ handle_options(Opts0) -> versions = Versions, verify = validate_option(verify, Verify), verify_fun = VerifyFun, + partial_chain = PartialChainHanlder, fail_if_no_peer_cert = FailIfNoPeerCert, verify_client_once = handle_option(verify_client_once, Opts, false), depth = handle_option(depth, Opts, 1), @@ -656,7 +660,7 @@ handle_options(Opts0) -> }, CbInfo = proplists:get_value(cb_info, Opts, {gen_tcp, tcp, tcp_closed, tcp_error}), - SslOptions = [protocol, versions, verify, verify_fun, + SslOptions = [protocol, versions, verify, verify_fun, partial_chain, fail_if_no_peer_cert, verify_client_once, depth, cert, certfile, key, keyfile, password, cacerts, cacertfile, dh, dhfile, @@ -708,6 +712,8 @@ validate_option(verify_fun, Fun) when is_function(Fun) -> end, Fun}; validate_option(verify_fun, {Fun, _} = Value) when is_function(Fun) -> Value; +validate_option(partial_chain, Value) when is_function(Value) -> + Value; validate_option(fail_if_no_peer_cert, Value) when is_boolean(Value) -> Value; validate_option(verify_client_once, Value) when is_boolean(Value) -> @@ -1147,25 +1153,32 @@ handle_verify_options(Opts, CaCerts) -> UserFailIfNoPeerCert = handle_option(fail_if_no_peer_cert, Opts, false), UserVerifyFun = handle_option(verify_fun, Opts, undefined), - + PartialChainHanlder = handle_option(partial_chain, Opts, + fun(_) -> unknown_ca end), + %% Handle 0, 1, 2 for backwards compatibility case proplists:get_value(verify, Opts, verify_none) of 0 -> {verify_none, false, - ca_cert_default(verify_none, VerifyNoneFun, CaCerts), VerifyNoneFun}; + ca_cert_default(verify_none, VerifyNoneFun, CaCerts), + VerifyNoneFun, PartialChainHanlder}; 1 -> {verify_peer, false, - ca_cert_default(verify_peer, UserVerifyFun, CaCerts), UserVerifyFun}; + ca_cert_default(verify_peer, UserVerifyFun, CaCerts), + UserVerifyFun, PartialChainHanlder}; 2 -> {verify_peer, true, - ca_cert_default(verify_peer, UserVerifyFun, CaCerts), UserVerifyFun}; - verify_none -> + ca_cert_default(verify_peer, UserVerifyFun, CaCerts), + UserVerifyFun, PartialChainHanlder}; + verify_none -> {verify_none, false, - ca_cert_default(verify_none, VerifyNoneFun, CaCerts), VerifyNoneFun}; + ca_cert_default(verify_none, VerifyNoneFun, CaCerts), + VerifyNoneFun, PartialChainHanlder}; verify_peer -> {verify_peer, UserFailIfNoPeerCert, - ca_cert_default(verify_peer, UserVerifyFun, CaCerts), UserVerifyFun}; + ca_cert_default(verify_peer, UserVerifyFun, CaCerts), + UserVerifyFun, PartialChainHanlder}; Value -> throw({error, {options, {verify, Value}}}) end. diff --git a/lib/ssl/src/ssl_certificate.erl b/lib/ssl/src/ssl_certificate.erl index 53366b060c..9c0ed181fe 100644 --- a/lib/ssl/src/ssl_certificate.erl +++ b/lib/ssl/src/ssl_certificate.erl @@ -30,7 +30,7 @@ -include("ssl_internal.hrl"). -include_lib("public_key/include/public_key.hrl"). --export([trusted_cert_and_path/3, +-export([trusted_cert_and_path/4, certificate_chain/3, file_to_certificats/2, validate_extension/3, @@ -46,14 +46,14 @@ %%==================================================================== %%-------------------------------------------------------------------- --spec trusted_cert_and_path([der_cert()], db_handle(), certdb_ref()) -> +-spec trusted_cert_and_path([der_cert()], db_handle(), certdb_ref(), fun()) -> {der_cert() | unknown_ca, [der_cert()]}. %% %% Description: Extracts the root cert (if not presents tries to %% look it up, if not found {bad_cert, unknown_ca} will be added verification %% errors. Returns {RootCert, Path, VerifyErrors} %%-------------------------------------------------------------------- -trusted_cert_and_path(CertChain, CertDbHandle, CertDbRef) -> +trusted_cert_and_path(CertChain, CertDbHandle, CertDbRef, PartialChainHandler) -> Path = [Cert | _] = lists:reverse(CertChain), OtpCert = public_key:pkix_decode_cert(Cert, otp), SignedAndIssuerID = @@ -62,32 +62,23 @@ trusted_cert_and_path(CertChain, CertDbHandle, CertDbRef) -> {ok, IssuerId} = public_key:pkix_issuer_id(OtpCert, self), {self, IssuerId}; false -> - case public_key:pkix_issuer_id(OtpCert, other) of - {ok, IssuerId} -> - {other, IssuerId}; - {error, issuer_not_found} -> - case find_issuer(OtpCert, CertDbHandle) of - {ok, IssuerId} -> - {other, IssuerId}; - Other -> - Other - end - end + other_issuer(OtpCert, CertDbHandle) end, case SignedAndIssuerID of {error, issuer_not_found} -> %% The root CA was not sent and can not be found. - {unknown_ca, Path}; + handle_incomplete_chain(Path, PartialChainHandler); {self, _} when length(Path) == 1 -> {selfsigned_peer, Path}; {_ ,{SerialNr, Issuer}} -> case ssl_manager:lookup_trusted_cert(CertDbHandle, CertDbRef, SerialNr, Issuer) of - {ok, {BinCert,_}} -> - {BinCert, Path}; + {ok, Trusted} -> + %% Trusted must be selfsigned or it is an incomplete chain + handle_path(Trusted, Path, PartialChainHandler); _ -> %% Root CA could not be verified - {unknown_ca, Path} + handle_incomplete_chain(Path, PartialChainHandler) end end. @@ -222,28 +213,27 @@ certificate_chain(CertDbHandle, CertsDbRef, Chain, SerialNr, Issuer, _SelfSigned _ -> %% The trusted cert may be obmitted from the chain as the %% counter part needs to have it anyway to be able to - %% verify it. This will be the normal case for servers - %% that does not verify the clients and hence have not - %% specified the cacertfile. + %% verify it. {ok, lists:reverse(Chain)} end. find_issuer(OtpCert, 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 - true -> - throw(public_key:pkix_issuer_id(ErlCertCandidate, self)); - false -> - Acc - end; - false -> - Acc - end; - (_, Acc) -> - Acc - end, + 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 + true -> + throw(public_key:pkix_issuer_id(ErlCertCandidate, self)); + false -> + Acc + end; + false -> + Acc + end; + (_, Acc) -> + Acc + end, try ssl_pkix_db:foldl(IsIssuerFun, issuer_not_found, CertDbHandle) of issuer_not_found -> @@ -275,3 +265,41 @@ public_key(#'OTPSubjectPublicKeyInfo'{algorithm = #'PublicKeyAlgorithm'{algorith parameters = {params, Params}}, subjectPublicKey = Key}) -> {Key, Params}. + +other_issuer(OtpCert, CertDbHandle) -> + case public_key:pkix_issuer_id(OtpCert, other) of + {ok, IssuerId} -> + {other, IssuerId}; + {error, issuer_not_found} -> + case find_issuer(OtpCert, CertDbHandle) of + {ok, IssuerId} -> + {other, IssuerId}; + Other -> + Other + end + end. + +handle_path({BinCert, OTPCert}, Path, PartialChainHandler) -> + case public_key:pkix_is_self_signed(OTPCert) of + true -> + {BinCert, Path}; + false -> + handle_incomplete_chain(Path, PartialChainHandler) + end. + +handle_incomplete_chain(Chain, Fun) -> + case catch Fun(Chain) of + {trusted_ca, DerCert} -> + new_trusteded_chain(DerCert, Chain); + unknown_ca = Error -> + {Error, Chain}; + _ -> + {unknown_ca, Chain} + end. + +new_trusteded_chain(DerCert, [DerCert | Chain]) -> + {DerCert, Chain}; +new_trusteded_chain(DerCert, [_ | Rest]) -> + new_trusteded_chain(DerCert, Rest); +new_trusteded_chain(_, []) -> + unknown_ca. diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl index 4ac4e81d9e..8ff9913cee 100644 --- a/lib/ssl/src/ssl_connection.erl +++ b/lib/ssl/src/ssl_connection.erl @@ -414,7 +414,9 @@ certify(#certificate{} = Cert, ssl_options = Opts} = State, Connection) -> case ssl_handshake:certify(Cert, CertDbHandle, CertDbRef, Opts#ssl_options.depth, Opts#ssl_options.verify, - Opts#ssl_options.verify_fun, Role) of + Opts#ssl_options.verify_fun, + Opts#ssl_options.partial_chain, + Role) of {PeerCert, PublicKeyInfo} -> handle_peer_cert(Role, PeerCert, PublicKeyInfo, State#state{client_certificate_requested = false}, Connection); diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl index 94ffd180c5..22673e46e2 100644 --- a/lib/ssl/src/ssl_handshake.erl +++ b/lib/ssl/src/ssl_handshake.erl @@ -49,7 +49,7 @@ finished/5, next_protocol/1]). %% Handle handshake messages --export([certify/7, client_certificate_verify/6, certificate_verify/6, verify_signature/5, +-export([certify/8, client_certificate_verify/6, certificate_verify/6, verify_signature/5, master_secret/5, server_key_exchange_hash/2, verify_connection/6, init_handshake_history/0, update_handshake_history/2, verify_server_key/5 ]). @@ -383,13 +383,13 @@ verify_signature(_Version, Hash, {HashAlgo, ecdsa}, Signature, %%-------------------------------------------------------------------- -spec certify(#certificate{}, db_handle(), certdb_ref(), integer() | nolimit, - verify_peer | verify_none, {fun(), term}, + verify_peer | verify_none, {fun(), term}, fun(), client | server) -> {der_cert(), public_key_info()} | #alert{}. %% %% Description: Handles a certificate handshake message %%-------------------------------------------------------------------- certify(#certificate{asn1_certificates = ASN1Certs}, CertDbHandle, CertDbRef, - MaxPathLen, _Verify, VerifyFunAndState, Role) -> + MaxPathLen, _Verify, VerifyFunAndState, PartialChain, Role) -> [PeerCert | _] = ASN1Certs, ValidationFunAndState = @@ -421,7 +421,7 @@ certify(#certificate{asn1_certificates = ASN1Certs}, CertDbHandle, CertDbRef, try {TrustedErlCert, CertPath} = - ssl_certificate:trusted_cert_and_path(ASN1Certs, CertDbHandle, CertDbRef), + ssl_certificate:trusted_cert_and_path(ASN1Certs, CertDbHandle, CertDbRef, PartialChain), case public_key:pkix_path_validation(TrustedErlCert, CertPath, [{max_path_length, diff --git a/lib/ssl/src/ssl_internal.hrl b/lib/ssl/src/ssl_internal.hrl index fd0d87bd5f..85724de4bd 100644 --- a/lib/ssl/src/ssl_internal.hrl +++ b/lib/ssl/src/ssl_internal.hrl @@ -74,6 +74,7 @@ versions :: [ssl_record:ssl_version()], %% ssl_record:atom_version() in API verify :: verify_none | verify_peer, verify_fun, %%:: fun(CertVerifyErrors::term()) -> boolean(), + partial_chain :: fun(), fail_if_no_peer_cert :: boolean(), verify_client_once :: boolean(), %% fun(Extensions, State, Verify, AccError) -> {Extensions, State, AccError} -- cgit v1.2.3