Skip to content

Add the support of bypassing JWT authn for CORS requests #2139

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
istio-testing merged 4 commits into from
Mar 5, 2019
Merged

Add the support of bypassing JWT authn for CORS requests #2139

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
be7895d
Add the support of bypassing JWT authn for CORS requests
lei-tang Mar 5, 2019
2ec9a88
Bail out earlier for CORS preflight requests
lei-tang Mar 5, 2019
9fa92e3
Use OPTIONS constant value from Envoy
lei-tang Mar 5, 2019
9c275d4
Remove changing to lowercase
lei-tang Mar 5, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
42 changes: 28 additions & 14 deletions src/envoy/http/jwt_auth/jwt_authenticator.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,9 +25,12 @@ namespace {
// The HTTP header to pass verified token payload.
const LowerCaseString kJwtPayloadKey("sec-istio-auth-userinfo");

// The CORS OPTIONS HTTP method
const LowerCaseString kOptionsHttpMethod("options");

// Extract host and path from a URI
void ExtractUriHostPath(const std::string& uri, std::string* host,
std::string* path) {
void ExtractUriHostPath(const std::string &uri, std::string *host,
std::string *path) {
// Example:
// uri = "https://example.com/certs"
// pos : ^
Expand All @@ -49,16 +52,27 @@ void ExtractUriHostPath(const std::string& uri, std::string* host,

} // namespace

JwtAuthenticator::JwtAuthenticator(Upstream::ClusterManager& cm,
JwtAuthStore& store)
JwtAuthenticator::JwtAuthenticator(Upstream::ClusterManager &cm,
JwtAuthStore &store)
: cm_(cm), store_(store) {}

// Verify a JWT token.
void JwtAuthenticator::Verify(HeaderMap& headers,
JwtAuthenticator::Callbacks* callback) {
void JwtAuthenticator::Verify(HeaderMap &headers,
JwtAuthenticator::Callbacks *callback) {
headers_ = &headers;
callback_ = callback;

// Per the spec
// http://www.w3.org/TR/cors/#cross-origin-request-with-preflight-0, CORS
// pre-flight requests shouldn't include user credentials.
if (headers_->Method() &&
LowerCaseString(kOptionsHttpMethod) ==

@qiwzhang qiwzhang Mar 5, 2019

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think Envoy has fixed string for OPTIONS

https://github.com/envoyproxy/envoy/blob/master/source/common/http/headers.h#L176

@qiwzhang qiwzhang Mar 5, 2019

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I prefer to do this check in Fitler.cc right inside the decodeHeaders().

@lei-tang lei-tang Mar 5, 2019

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

decodeHeaders() does not have tests. Placing the check in Verify() will enable tests. Plus, placing the check in Verify() is equivalent to placing the check in decodeHeaders().

@lei-tang lei-tang Mar 5, 2019

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Done: changed to use the OPTIONS fixed string from Envoy.

LowerCaseString(headers_->Method()->value().c_str())) {
ENVOY_LOG(debug, "CORS preflight requests are passed through.");
DoneWithStatus(Status::OK);
return;
}

ENVOY_LOG(debug, "Jwt authentication starts");
std::vector<std::unique_ptr<JwtTokenExtractor::Token>> tokens;
store_.token_extractor().Extract(headers, &tokens);
Expand Down Expand Up @@ -119,7 +133,7 @@ void JwtAuthenticator::Verify(HeaderMap& headers,
FetchPubkey(issuer);
}

void JwtAuthenticator::FetchPubkey(PubkeyCacheItem* issuer) {
void JwtAuthenticator::FetchPubkey(PubkeyCacheItem *issuer) {
uri_ = issuer->jwt_config().remote_jwks().http_uri().uri();
std::string host, path;
ExtractUriHostPath(uri_, &host, &path);
Expand All @@ -130,7 +144,7 @@ void JwtAuthenticator::FetchPubkey(PubkeyCacheItem* issuer) {
message->headers().insertPath().value(path);
message->headers().insertHost().value(host);

const auto& cluster = issuer->jwt_config().remote_jwks().http_uri().cluster();
const auto &cluster = issuer->jwt_config().remote_jwks().http_uri().cluster();
if (cm_.get(cluster) == nullptr) {
DoneWithStatus(Status::FAILED_FETCH_PUBKEY);
return;
Expand All @@ -141,15 +155,15 @@ void JwtAuthenticator::FetchPubkey(PubkeyCacheItem* issuer) {
std::move(message), *this, Http::AsyncClient::RequestOptions());
}

void JwtAuthenticator::onSuccess(MessagePtr&& response) {
void JwtAuthenticator::onSuccess(MessagePtr &&response) {
request_ = nullptr;
uint64_t status_code = Http::Utility::getResponseStatus(response->headers());
if (status_code == 200) {
ENVOY_LOG(debug, "fetch pubkey [uri = {}]: success", uri_);
std::string body;
if (response->body()) {
auto len = response->body()->length();
body = std::string(static_cast<char*>(response->body()->linearize(len)),
body = std::string(static_cast<char *>(response->body()->linearize(len)),
len);
} else {
ENVOY_LOG(debug, "fetch pubkey [uri = {}]: body is empty", uri_);
Expand Down Expand Up @@ -177,7 +191,7 @@ void JwtAuthenticator::onDestroy() {
}

// Handle the public key fetch done event.
void JwtAuthenticator::OnFetchPubkeyDone(const std::string& pubkey) {
void JwtAuthenticator::OnFetchPubkeyDone(const std::string &pubkey) {
auto issuer = store_.pubkey_cache().LookupByIssuer(jwt_->Iss());
Status status = issuer->SetRemoteJwks(pubkey);
if (status != Status::OK) {
Expand All @@ -188,7 +202,7 @@ void JwtAuthenticator::OnFetchPubkeyDone(const std::string& pubkey) {
}

// Verify with a specific public key.
void JwtAuthenticator::VerifyKey(const PubkeyCacheItem& issuer_item) {
void JwtAuthenticator::VerifyKey(const PubkeyCacheItem &issuer_item) {
JwtAuth::Verifier v;
if (!v.Verify(*jwt_, *issuer_item.pubkey())) {
DoneWithStatus(v.GetStatus());
Expand Down Expand Up @@ -218,7 +232,7 @@ bool JwtAuthenticator::OkToBypass() {
return false;
}

void JwtAuthenticator::DoneWithStatus(const Status& status) {
void JwtAuthenticator::DoneWithStatus(const Status &status) {
ENVOY_LOG(debug, "Jwt authentication completed with: {}",
JwtAuth::StatusToString(status));
ENVOY_LOG(debug,
Expand All @@ -232,7 +246,7 @@ void JwtAuthenticator::DoneWithStatus(const Status& status) {
callback_ = nullptr;
}

const LowerCaseString& JwtAuthenticator::JwtPayloadKey() {
const LowerCaseString &JwtAuthenticator::JwtPayloadKey() {
return kJwtPayloadKey;
}

Expand Down
28 changes: 28 additions & 0 deletions src/envoy/http/jwt_auth/jwt_authenticator_test.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -530,6 +530,34 @@ TEST_F(JwtAuthenticatorTest, TestMissingJwtWhenAllowMissingOrFailedIsTrue) {
auth_->Verify(headers, &mock_cb_);
}

TEST_F(JwtAuthenticatorTest, TestMissingJwtWhenHttpMethodIsCORS) {
// In this test, when JWT is missing, the status should still be OK
// because CORS preflight requests shouldn't include user credentials.
EXPECT_CALL(mock_cm_, httpAsyncClientForCluster(_)).Times(0);
EXPECT_CALL(mock_cb_, onDone(_)).WillOnce(Invoke([](const Status &status) {
ASSERT_EQ(status, Status::OK);
}));

auto cors_headers =
TestHeaderMapImpl{{":method", "OPTIONS"}, {":path", "/any/cors-path"}};
auth_->Verify(cors_headers, &mock_cb_);
}

TEST_F(JwtAuthenticatorTest, TestInvalidJWTWhenHttpMethodIsCORS) {
// In this test, when JWT is invalid, the status should still be OK
// because CORS preflight requests are passed through.
EXPECT_CALL(mock_cm_, httpAsyncClientForCluster(_)).Times(0);
EXPECT_CALL(mock_cb_, onDone(_)).WillOnce(Invoke([](const Status &status) {
ASSERT_EQ(status, Status::OK);
}));

std::string token = "invalidToken";
auto cors_headers = TestHeaderMapImpl{{":method", "OPTIONS"},
{":path", "/any/cors-path"},
{"Authorization", "Bearer " + token}};
auth_->Verify(cors_headers, &mock_cb_);
}

TEST_F(JwtAuthenticatorTest, TestInValidJwtWhenAllowMissingOrFailedIsTrue) {
// In this test, when JWT is invalid, the status should still be OK
// because allow_missing_or_failed is true.
Expand Down