tls: report a fatal TLS error that arrives after the handshake by robobun · Pull Request #41272 · oven-sh/bun

robobun · 2026-09-03T08:28:58Z

Problem

A TLS 1.3 server with requestCert and rejectUnauthorized rejects a client that has no certificate. The Bun client emits secureConnect, end, close. Node emits error before end.
TLS 1.3 finishes the client's handshake first, so the server's alert arrives after it. us_internal_ssl_on_data (packages/bun-usockets/src/crypto/openssl.c:2621) keeps the SSL_read reason only during the handshake. Later it drops the reason and the data from that read.

Fix

After the handshake, openssl.c now delivers the decrypted data, passes the BoringSSL error to the socket (us_dispatch_ssl_error), and closes it.
NewSocket::on_ssl_error calls the error handler with true as a third argument. With no handler, the socket only closes, so a peer cannot cause an uncaught exception.
With that argument, node:tls sockets emit the error and keep the socket, like Node's onerror. The close then gives end and close.
Verified: new tests in node-tls-cert.test.ts, node-tls-server.test.ts and socket.test.ts fail on released Bun. The node:tls cases also pass on Node.js v26.3.0. Also ran test/js/node/tls/, test/js/bun/net/, Node's test-tls-* and test-https-*.

Background

A fatal alert is a TLS record that ends the session. BoringSSL reports it as a failed SSL_read, with the reason on the thread's error queue.
Node's TLSWrap::ClearOut delivers the decrypted data, then calls the JS onerror. On an established session, onerror emits error and keeps the socket.
openssl.c drives BoringSSL for Bun.connect, Bun.listen and node:net. It calls Rust through us_dispatch_*.
The code is the BoringSSL name, ERR_SSL_TLSV1_ALERT_CERTIFICATE_REQUIRED. Node's test-tls-client-auth.js expects that name when process.features.openssl_is_boringssl is true.

Notes

Event order, TLS 1.3, client with no certificate. The result is the same for a Bun client with a Node server, a Node client with a Bun server, and Bun with Bun:
- Node 26.3.0: secureConnect, error, end, close(false)
- Bun 1.4.1: secureConnect, end, close(false)
- this PR: the same as Node
The TLS 1.3 case of Node's test/parallel/test-tls-client-auth.js (v26.3.0) passes with this PR. On 1.4.1 it hangs, because its cleanup waits for the client error.
Node with OpenSSL reports ERR_SSL_TLSV13_ALERT_CERTIFICATE_REQUIRED. BoringSSL names the same reason TLSV1_ALERT_CERTIFICATE_REQUIRED, and all other Bun ERR_SSL_* codes use BoringSSL names too.
A record that does not decrypt: BoringSSL queues the cipher's BAD_DECRYPT ahead of the TLS reason. The fix reports the first SSL-library entry, so the code is ERR_SSL_DECRYPTION_FAILED_OR_BAD_RECORD_MAC, the same as Node 26 on TLS 1.3.
When the read that fails also finished the handshake, the handshake is reported first, then the error, as Node does.
TLS 1.2 does not change. There the alert arrives during the handshake, and that path already reports it.
The renegotiation failure path does not change.
The data delivery applies to every socket kind. fetch, the WebSocket client and Bun.serve now get the bytes from the read that fails, the same as when the bad record comes in a later read. Before, fetch reported ECONNRESET for a complete response that shared a read with a bad record.
Known difference: with an onread callback that returns false, the error comes before the rest of that chunk. Node delivers the whole chunk first.
Only BunSocketTls sockets get the dispatch. fetch, the WebSocket client, Bun.RedisClient and the SQL drivers keep the old close. Bun.serve and the node:http(s) server run on uWS sockets, so a bad record there still gives no clientError.
A node:tls server socket now gives error, end, close(false), the same as Node. It has an internal error listener, so a server with no listener of its own gets no uncaught exception.
With a write pending, both handler tables keep the old path: the write callback gets the error, and the socket is destroyed.
An error that a handler throws comes with no third argument, so it still destroys the socket. A check of the code (/^ERR_(SSL|OSSL)_/) would also match an error that a data listener throws, for example ERR_OSSL_PEM_NO_START_LINE from tls.createSecureContext().
Not covered: node:tls over the Rust SSLWrapper. That is a generic Duplex, a named pipe, or a net.Socket with unflushed writes (src/js/node/net.ts:2022). That path clears the reason at src/uws/lib.rs:992, also during the handshake, so it still ends with no error.
Related PRs:
- This supersedes tls: report a fatal TLS alert received after the handshake completes #33294, which takes the same approach and now has merge conflicts. That PR raises an uncaught exception when a socket has no error handler. It also picks the TLS error by its code (EPROTO) in net.ts, so an error that a handler throws with that code takes the same path.
- node:tls: abort handshake with fatal alert when server rejects client cert #33630 pins its new test to TLS 1.2, because on TLS 1.3 the alert arrives after secureConnect.
- node: fix the genuine-hang class — MessagePort loop starvation, pinned sockets, https handshakeTimeout, TLS alert errors (+2 tests) #35538 also changes this branch. It passes the reason through the close, so the client gets error and close(true), and no end.
node-tls-server.test.ts also gets the fix from tls: report a fatal TLS alert received after the handshake completes #33294 for the SNICallback test. That test dialed localhost again after it listened on localhost, and failed when the two resolved to different address families.
Node.js v26.3.0 parity of the tests: the node:tls cases were run on Node as plain scripts (the files use bun:test, which Node cannot load). All five pass on both runtimes. To get there, the TLS 1.3 case uses a 2048-bit CA (OpenSSL rejects the 1024-bit agent10 CA) and takes the alert name from process.features.openssl_is_boringssl. The accepted-socket cases send the FIN with the bad record, because Node keeps an errored socket open until the peer goes away, while Bun closes it.
Known difference that stays: after a fatal TLS error on an established session, Bun closes the connection and Node leaves it open for the peer to close. Bun closed it before this PR too.
Suites, debug build:
- test/js/node/tls/ and test/js/bun/net/: all pass except one test in socket.test.ts that needs the internet.
- Node test-tls-*.js and test-https-*.js: 244 of 245 pass. test-https-timeout.js hangs, and it hangs the same way on a debug build of this branch's base without the fix. The 1.4.1 release build passes it.

no test proof · iteration 0 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/node/tls/node-tls-server.test.ts, test/js/bun/net/socket.test.ts

A TLS 1.3 server that requires a client certificate sends its certificate_required alert after the client finished the handshake. The SSL_read failure path dropped the reason once the handshake was done and closed the socket as if the peer had ended it. node:tls clients saw 'secureConnect', 'end' and 'close', with no 'error'. A record that does not decrypt was dropped the same way, together with the data that was decrypted in the same read. openssl.c now delivers the data that this read decrypted, then hands the BoringSSL error to the socket, then closes it. When the same read also finished the handshake, it reports the handshake first. The error handler gets true as a third argument. node:tls client and server sockets use it to emit the error like Node's onerror, without a destroy, so 'end' and 'close' follow. A Bun.connect or Bun.listen socket gets the error in its error handler, when it has one. The code is BoringSSL's name for the alert, ERR_SSL_TLSV1_ALERT_CERTIFICATE_REQUIRED, which is what Node's own test expects when process.features.openssl_is_boringssl is true. The SNICallback test in node-tls-server.test.ts now dials the address that the listener bound to.

robobun · 2026-09-03T08:29:04Z

Status

Reproduced with a TLS 1.3 tls.createServer({ requestCert: true, rejectUnauthorized: true }) and a tls.connect() client that has no certificate. Released Bun gives secureConnect, end, close(false). Node 26.3.0 gives secureConnect, error, end, close(false).
With this PR, Bun gives the Node order for a Bun client with a Node server, a Node client with a Bun server, and Bun with Bun.
The new tests fail on released Bun and pass on a debug build of this branch.
The node:tls cases also pass on Node.js v26.3.0 (68b1a2c). The results per case are in this comment.
Waiting for CI.

robobun · 2026-09-03T08:29:16Z

^{Updated 5:15 PM PT - Sep 10th, 2026}

✅ @robobun, your commit 68b1a2c0dd4fca782d399866012d70a30e054e8e passed in Build #114006! 🎉

🧪 To try this PR locally:

bunx bun-pr 41272

That installs a local version of the PR into your bun-41272 executable, so you can run:

bun-41272 --bun

coderabbitai · 2026-09-03T08:40:23Z

Walkthrough

Changes

The TLS read path now preserves pending handshake events and decrypted data before dispatching fatal post-handshake errors. Native errors flow through the runtime to JavaScript handlers, and tests cover event ordering, malformed records, certificate alerts, and missing client certificates.

Fatal TLS error handling

Layer / File(s)	Summary
Native TLS error flow `packages/bun-usockets/src/crypto/openssl.c`, `packages/bun-usockets/src/internal/internal.h`	Fatal SSL read errors now flush pending TLS events and plaintext, dispatch the first SSL error, and then close the socket.
Runtime TLS error dispatch `src/runtime/socket/uws_dispatch.rs`, `src/runtime/socket/socket_body.rs`, `src/js/node/net.ts`	The native error callback forwards fatal TLS errors to the TLS socket. JavaScript handlers emit the error without explicitly destroying established sockets.
TLS error regression coverage `test/js/bun/net/socket.test.ts`, `test/js/node/tls/node-tls-cert.test.ts`, `test/js/node/tls/node-tls-server.test.ts`	Tests cover post-handshake alerts, certificate errors, event ordering, preserved data, malformed records, and SNI setup.

Suggested reviewers: dylan-conway, jarred-sumner, cirospaciari

Merge Risk: 🟡 Moderate · up to f4610

Fatal TLS error handling can leave runtime termination state unpropagated and trigger failures during later dispatch processing, so this should be corrected before merge.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description check	✅ Passed	The description covers the problem, fix, verification steps, background, known differences, and test results. It provides sufficient detail for review.
Title check	✅ Passed	The title clearly and concisely identifies the main change: reporting fatal TLS errors received after the handshake.

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Actionable comments posted: 2

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Inline comments:
In `@src/runtime/socket/socket_body.rs`:
- Around line 2120-2125: Update the on_ssl_error flow after the nested
global.bun_vm().event_loop_mut().run_callback invocation to return
Err(jsc::JsError::Thrown) when global.has_exception() is true; otherwise
preserve the existing Ok(()) result so us_dispatch_ssl_error and dispatch::fold
receive pending termination correctly.

In `@test/js/node/tls/node-tls-cert.test.ts`:
- Around line 163-169: Condense the comments above the TLS client-certificate
assertions to one line that preserves both facts: TLS 1.3 may emit the
certificate-required error after secureConnect due to handshake ordering, and
the expected alert name differs between BoringSSL and OpenSSL.

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packages/bun-usockets/src/crypto/openssl.c
packages/bun-usockets/src/internal/internal.h
src/js/node/net.ts
src/runtime/socket/socket_body.rs
src/runtime/socket/uws_dispatch.rs
test/js/bun/net/socket.test.ts
test/js/node/tls/node-tls-cert.test.ts
test/js/node/tls/node-tls-server.test.ts

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…e line each

robobun · 2026-09-03T08:46:02Z

Review follow-up:

socket_body.rs, a pending termination after run_callback: no change. run_callback takes the exception of the call. The microtask drain runs when the scope drops, the same as in on_session and on_keylog. The thread has the details.
node-tls-cert.test.ts: the comment is three lines now (76d70f2).
The new comments under src/ are one line each (ab97d87). This commit changes only comments.

claude

Code review found no issues

No high-confidence issues detected in this change.

robobun · 2026-09-06T07:29:01Z

Related: #41463 fixed the same branch of us_internal_ssl_on_data (bad record after the handshake) and is closed in favour of this PR, which is older and matches Node's post-handshake order (error, then end, then close(false)). Two pieces from that branch (robobun/30172bf2/tls-post-handshake-ssl-error, 1be57a8) may be useful here:

A deterministic bad-record test: a TCP proxy between a tls.connect client and a tls.createServer server writes 17 03 03 00 20 plus 32 bytes of 0x42 toward the server once it has emitted secureConnection. Node 26.3.0 reports ERR_SSL_DECRYPTION_FAILED_OR_BAD_RECORD_MAC on the server and the alert (ERR_SSL_*ALERT_BAD_RECORD_MAC) on the client. A 5-byte body gives BAD_PACKET_LENGTH under BoringSSL, so the body has to be at least an AEAD tag long.
The first-ERR_LIB_SSL picker also applies to the handshake path (ssl_park_fatal_reason uses ERR_peek_error, the oldest entry). Hoisting the loop into one helper and using it there keeps both paths consistent.

cirospaciari · 2026-09-10T20:09:17Z

@robobun please run the tests this PR adds or changes on Node.js v26.3.0 and report whether each one passes or fails.
They must pass on both Bun and Node v26.3.0, so fix any case that only passes on Bun.

The TLS 1.3 client-certificate case used the agent10 fixtures, whose CA key is 1024 bits. Node's OpenSSL rejects that key as too weak before the handshake reaches the alert. It now uses the 2048-bit harness certificate, and it takes the alert name for the crypto library it runs on: BoringSSL names it TLSV1_ALERT_CERTIFICATE_REQUIRED, OpenSSL names it TLSV13_ALERT_CERTIFICATE_REQUIRED. The accepted-socket cases waited for a close that Node does not send. Node keeps an errored TLS socket open until the peer goes away, so each client now sends its bad record and the FIN together, the way a peer that gives up does. Both runtimes then give the error, 'end' and close(false). The reason string of a record that does not decrypt is compared in one spelling: BoringSSL reports DECRYPTION_FAILED_OR_BAD_RECORD_MAC, OpenSSL reports the same reason in words.

claude

Code review found no issues

No high-confidence issues detected in this change.

robobun · 2026-09-10T23:52:10Z

@cirospaciari Done. These test files use bun:test and Bun.jest (createTest), so Node cannot load them. I copied each test body this PR adds or changes into a plain script, with node:assert in place of expect, and ran the same file on Node.js v26.3.0 and on Bun.

As first pushed (ab97d87): 4 of 5 failed on Node.

test	Node v26.3.0	why
`node-tls-cert`: Request cert from TLS1.3 client that doesn't have one.	fail	client error `UNSPECIFIED` (`CA certificate key too weak`), `close true`. The handshake never reached the alert.
`node-tls-server`: reports a record that does not decrypt as an 'error'	fail	got the `error`, then no `close`. Timed out.
`node-tls-server`: delivers the data that arrives with the bad record	fail	the same: `data`, `error`, then no `close`.
`node-tls-server`: reports the handshake then the 'error' (one read)	fail	the same: `secureConnection`, `error`, then no `close`.
`node-tls-server`: SNICallback runs for the bind hostname (changed test)	pass

Now (68b1a2c): 5 of 5 pass on Node and on Bun.

test	Node v26.3.0	Bun (this PR)
`node-tls-cert`: Request cert from TLS1.3 client that doesn't have one.	pass	pass
`node-tls-server`: reports a record that does not decrypt as an 'error'	pass	pass
`node-tls-server`: delivers the data that arrives with the bad record	pass	pass
`node-tls-server`: reports the handshake then the 'error' (one read)	pass	pass
`node-tls-server`: SNICallback runs for the bind hostname	pass	pass
`socket.test.ts`: a fatal TLS alert that arrives after the handshake (2 cases)	n/a	pass

The socket.test.ts cases call Bun.connect and Bun.listen, which Node does not have. The node:tls cases above cover the same alert through the Node API.

What was wrong with the tests, and the fix:

The TLS 1.3 client-certificate case used the agent10 fixtures. Their CA key is 1024 bits, and Node's OpenSSL refuses it. The case now uses the 2048-bit harness certificate.
The same case expected ERR_SSL_TLSV1_ALERT_CERTIFICATE_REQUIRED, which is the BoringSSL name. OpenSSL names the alert ERR_SSL_TLSV13_ALERT_CERTIFICATE_REQUIRED. The case now picks the name from process.features.openssl_is_boringssl, as Node's own test-tls-client-auth.js does.
The three accepted-socket cases waited for a close that Node never sends by itself. Node keeps an errored TLS socket open until the peer goes away. Each client now sends its bad record and the FIN together, the way a peer that gives up does. Both runtimes then give error, end, close(false).
The reason of a record that does not decrypt is DECRYPTION_FAILED_OR_BAD_RECORD_MAC on BoringSSL and decryption failed or bad record mac on OpenSSL. The test now compares one spelling. The code and library are equal on both.

Point 3 shows one behavior difference that this PR does not change. After a fatal TLS error on an established session, Bun closes the connection. Node leaves it open until the peer closes. Bun closed it before this PR too, only with no error event. I can make Bun keep the socket open like Node in this PR if you want that. It is a larger change in openssl.c, because the SSL object cannot read or write after a fatal error.

Stability of the fixed cases: the script passed 15 of 15 runs on Node and 10 of 10 on a debug build of this branch. The real test files passed 8 of 8 runs with bun bd test. The four cases that prove the fix still fail on released Bun (1.4.3).

Raw output

$ node ports-orig.mjs        # the tests as first pushed
FAIL  node v26.3.0  node-tls-cert: Request cert from TLS1.3 client that doesn't have one.
      +   'error UNSPECIFIED',
      +   'close true'
      -   'secureConnect',
      -   'error ERR_SSL_TLSV1_ALERT_CERTIFICATE_REQUIRED',
FAIL  node v26.3.0  node-tls-server: reports a record that does not decrypt as an 'error'
      timed out after 10s (no 'close')
FAIL  node v26.3.0  node-tls-server: delivers the data that arrives with the bad record
      timed out after 10s (no 'close')
FAIL  node v26.3.0  node-tls-server: reports the handshake then the 'error' (one read)
      timed out after 10s (no 'close')
PASS  node v26.3.0  node-tls-server: SNICallback runs for the bind hostname

$ node ports.mjs             # the tests at 68b1a2c0dd
PASS  node v26.3.0  node-tls-cert: Request cert from TLS1.3 client that doesn't have one.
PASS  node v26.3.0  node-tls-server: reports a record that does not decrypt as an 'error'
PASS  node v26.3.0  node-tls-server: delivers the data that arrives with the bad record
PASS  node v26.3.0  node-tls-server: reports the handshake then the 'error' (one read)
PASS  node v26.3.0  node-tls-server: SNICallback runs for the bind hostname

$ bun-debug ports.mjs        # this branch
PASS  bun 1.4.1-debug  (the same five)

$ bun ports.mjs              # released 1.4.3, without the fix
FAIL  bun 1.4.3  node-tls-cert: Request cert from TLS1.3 client that doesn't have one.
      -   'error ERR_SSL_TLSV1_ALERT_CERTIFICATE_REQUIRED',
FAIL  bun 1.4.3  node-tls-server: reports a record that does not decrypt as an 'error'
...

… a clean close (#41507) Stacked on #41463. Review the last commit only. ### Problem - `tls.connect({ socket: <Duplex> })` (and node:tls over a Windows named pipe) emits a clean `'end'` and `'close'` with `hadError` false when a TLS record fails after the handshake: a bad MAC, a wrong version, a peer's fatal alert. Node emits the socket's `ERR_SSL_<REASON>` `'error'` (for example `ERR_SSL_DECRYPTION_FAILED_OR_BAD_RECORD_MAC`). - The cause is `SSLWrapper::handle_reading` (`src/uws/lib.rs:1030`). On `SSL_ERROR_SSL` it called `ERR_clear_error()` right after `SSL_get_error()` and closed through `Handlers::on_close`, which carried no reason. The alert BoringSSL sealed into the write BIO was dropped too. #41463 fixes the same bug for the uSockets engine. The SSLWrapper engine is a separate `SSL_read` driver, so that fix does not reach it. ### Fix - `handle_reading` takes the root-cause reason before the queue is cleared, through `us_ssl_take_fatal_reason`, the picker openssl.c uses for its own fatal close. It then flushes the sealed alert to the peer and closes with the reason. - `Handlers::on_close` carries `Option<&CStr>`. `UpgradedDuplex` and `WindowsNamedPipe` forward it into `TLSSocket::on_close` through the close reason slot that #41463 added. A named pipe close deferred by a busy writer keeps an owned copy. The fetch and WebSocket proxy tunnels ignore it. `write_data` no longer closes the wrapper while a fatal read is mid-dispatch, so a `'data'` listener that writes back cannot hide the reason. - Correct because the reason then reaches JS through the same `EPROTO` shape and the same `node:net` decomposition as the uSockets path. Both engines report one result for one failure. - Verified: `test/js/node/tls/node-tls-connect.test.ts` ("tls.connect over a Duplex reports a fatal post-handshake SSL error", three cases). All three fail on the #41463 base and pass with this branch. The same cases also pass on Node.js v26.3.0 (see the comment below). Also `test/js/node/tls/`, `test/js/bun/net/socket.test.ts`, and the fetch and WebSocket proxy suites. ### Background - `SSLWrapper` (`src/uws/lib.rs`) runs BoringSSL over memory BIOs for transports that are not a `us_socket_t`: a generic `Duplex`, a Windows named pipe, the fetch and WebSocket proxy tunnels. It calls its owner back through `Handlers` (`on_data`, `write`, `on_close`). - Error queue: OpenSSL keeps a per-thread error queue. A fatal `SSL_read` leaves the reason there. Node reports the oldest entry. BoringSSL can queue a cipher-layer entry first, so the picker takes the oldest SSL-library entry. - Fatal alert: on a failed read BoringSSL writes an alert record into the write BIO. Nothing pumps that BIO after a close, so `handle_reading` now flushes it before the close. The peer then gets its own `ERR_SSL_*ALERT_*` error. <details><summary>Notes</summary> - Repro: a TCP proxy between a `Duplex`-wrapped client and `tls.createServer`. After `secureConnect`, write an application_data record (`17 03 03 00 20` plus 32 bytes of `0x42`) toward the client. Node v26.3.0: `error ERR_SSL_DECRYPTION_FAILED_OR_BAD_RECORD_MAC`. Bun 1.4.3-canary: `end`, `close false`. With the fix: `error ERR_SSL_DECRYPTION_FAILED_OR_BAD_RECORD_MAC`, `close true`. - Written toward the server instead, the server's `bad_record_mac` alert reaches the client as `ERR_SSL_SSLV3_ALERT_BAD_RECORD_MAC` (BoringSSL's name for the alert). - Node leaves the TLSSocket open after the `'error'`. Bun destroys it with the error, because the engine's only exit on a fatal read is a close. #41463 made the same choice for the uSockets path. - The alert flush was checked on the wire: the client sends a 19-byte application_data record (a TLS 1.3 encrypted alert) before the FIN. - The tests assert only what holds on both runtimes: the first event is `'error'` with the `ERR_SSL_*` code and `library: "SSL routines"`. The alert's code name comes from `process.features.openssl_is_boringssl` (BoringSSL: `SSLV3_ALERT_BAD_RECORD_MAC`, OpenSSL 3: `SSL/TLS_ALERT_BAD_RECORD_MAC`). - Self-reviewed: 9 concerns raised, 7 addressed (stacked on #41463 instead of main, the shared `net.ts` and `NewSocket::on_close` hunks dropped, the picker shared with openssl.c instead of a Rust copy, the node `'close'` wording fixed). Not addressed: the Http2SecureServer upgrade path (`_http2_upgrade.ts` `socketClose`) still drops the reason on this engine, and #32929 (the handshake-time reason on this engine) is not stacked under this PR. Both are separate changes. - #41272 is an alternative shape for the uSockets path (an `error` dispatch before the close). It states that it does not cover the SSLWrapper engine. If that shape lands instead of #41463, the reason capture and the alert flush here stay, and only the final dispatch in `DuplexUpgradeContext::on_close` changes. - Pre-existing failures in this container, not from this change: `SNICallback runs even when the requested servername matches the bind hostname` (localhost dual-stack) and `socket > should not call drain before handshake` (needs www.example.com). - Cross-checked with `cargo check -p bun_runtime --target x86_64-pc-windows-msvc`. </details>  --- **[human-review]** gate passed · iteration 1 · 9 files touched <details><summary>fails on main (without fix)</summary> ```console ASAN without fix: 3 failed, 18 skipped $ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" test/js/node/tls/node-tls-connect.test.ts bun test v1.4.3 (4ff9193) test/js/node/tls/node-tls-connect.test.ts: (pass) should have checkServerIdentity [2.59ms] (pass) should thow ECONNRESET if FIN is received before handshake [323.96ms] (pass) initializes authorizationError to null in the TLSSocket constructor [7.81ms] (pass) setMaxSendFragment mirrors OpenSSL's [512, 16384] acceptance without throwing [113.40ms] (pass) should be able to grab the JSStreamSocket constructor [13.14ms] (skip) tls.connect > should work with alpnProtocols (pass) tls.connect > Bun.serve() should work with tls and Bun.file() [80.19ms] (pass) tls.connect > should have peer certificate when using self asign certificate [83.18ms] (skip) tls.connect > should have peer certificate (skip) tls.connect > getCipher, getProtocol, getEphemeralKeyInfo, getSharedSigalgs, getSession, exportKeyingMaterial and isSessionReused should work (skip) tls.connect > should process options correctly when connect is called with only options (skip) tls.connect > should process port an ... (truncated) release without fix: 3 failed, 18 skipped bun test v1.4.3-canary.1 (4ff9193) test/js/node/tls/node-tls-connect.test.ts: (pass) should have checkServerIdentity [0.06ms] (pass) should thow ECONNRESET if FIN is received before handshake [6.51ms] (pass) initializes authorizationError to null in the TLSSocket constructor [0.16ms] (pass) setMaxSendFragment mirrors OpenSSL's [512, 16384] acceptance without throwing [3.49ms] (pass) should be able to grab the JSStreamSocket constructor [0.21ms] (skip) tls.connect > should work with alpnProtocols (pass) tls.connect > Bun.serve() should work with tls and Bun.file() [7.36ms] (pass) tls.connect > should have peer certificate when using self asign certificate [4.22ms] (skip) tls.connect > should have peer certificate (skip) tls.connect > getCipher, getProtocol, getEphemeralKeyInfo, getSharedSigalgs, getSession, exportKeyingMaterial and isSessionReused should work (skip) tls.connect > should process options correctly when connect is called with only options (skip) tls.connect > should process port and host correctly (skip) tls.connect > should process port, host, and callback correctly (skip) tls.connect > should handle the absence of a callback gracefully (skip) tls.c ... (truncated) ``` </details> <details><summary>passes on PR (with fix)</summary> ```console ASAN with fix: 18 skipped $ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" test/js/node/tls/node-tls-connect.test.ts bun test v1.4.3 (4ff9193) test/js/node/tls/node-tls-connect.test.ts: (pass) should have checkServerIdentity [2.58ms] (pass) should thow ECONNRESET if FIN is received before handshake [316.01ms] (pass) initializes authorizationError to null in the TLSSocket constructor [7.39ms] (pass) setMaxSendFragment mirrors OpenSSL's [512, 16384] acceptance without throwing [113.24ms] (pass) should be able to grab the JSStreamSocket constructor [12.50ms] (skip) tls.connect > should work with alpnProtocols (pass) tls.connect > Bun.serve() should work with tls and Bun.file() [75.11ms] (pass) tls.connect > should have peer certificate when using self asign certificate [80.40ms] (skip) tls.connect > should have peer certificate (skip) tls.connect > getCipher, getProtocol, getEphemeralKeyInfo, getSharedSigalgs, getSession, exportKeyingMaterial and isSessionReused should work (skip) tls.connect > should process options correctly when connect is called with only options (skip) tls.connect > should process port an ... (truncated) release with fix: 18 skipped $ bun scripts/build.ts --profile=release [configured] bun-profile → bun (stripped) in 602ms (unchanged) ninja: Entering directory `/workspace/bun/build/release' [1/7] cc obj/packages/bun-usockets/src/crypto/openssl.c.o [2/7] gen generated_host_exports.rs generated_host_exports.rs: 122 exports (host=5, lazy=10, generic=107, rust=0); 242 extern-C blocks audited [2/7] cargo bun_runtime → libbun_runtime.a �[1m�[92m Compiling�[0m bun_core v0.0.0 (/workspace/bun/src/bun_core) �[1m�[92m Compiling�[0m bun_errno v0.0.0 (/workspace/bun/src/errno) �[1m�[92m Compiling�[0m bun_ptr v0.0.0 (/workspace/bun/src/ptr) �[1m�[92m Compiling�[0m bun_boringssl_sys v0.0.0 (/workspace/bun/src/boringssl_sys) �[1m�[92m Compiling�[0m bun_safety v0.0.0 (/workspace/bun/src/safety) �[1m�[92m Compiling�[0m bun_base64 v0.0.0 (/workspace/bun/src/base64) �[1m�[92m Compiling�[0m bun_cares_sys v0.0.0 (/workspace/bun/src/cares_sys) �[1m�[92m Compiling�[0m bun_zlib_sys v0.0.0 (/workspace/bun/src/zlib_sys) �[1m�[92m Compiling�[0m bun_zstd v0.0.0 (/workspace/bun/src/zstd) �[1m�[92m Compiling�[0m bun_picohttp v0.0.0 (/workspace/bun/src/picohttp) �[1m�[92m Compiling�[0m bun_brotli v0 ... (truncated) ``` </details> <details><summary>diff hotspot</summary> ``` packages/bun-usockets/src/crypto/openssl.c | 20 +++- src/http/ProxyTunnel.rs | 2 +- .../websocket_client/WebSocketProxyTunnel.rs | 2 +- src/runtime/socket/UpgradedDuplex.rs | 7 +- src/runtime/socket/WindowsNamedPipe.rs | 22 +++- src/runtime/socket/WindowsNamedPipeContext.rs | 8 +- src/runtime/socket/socket_body.rs | 18 +-- src/uws/lib.rs | 73 +++++++++--- test/js/node/tls/node-tls-connect.test.ts | 124 +++++++++++++++++++++ 9 files changed, 234 insertions(+), 42 deletions(-) ``` </details> **gate history** · 3 passed · 0 rejected · iteration 1 <details><summary>evidence per changed file</summary> ``` file reads edits tests packages/bun-usockets/src/crypto/openssl.c 0 0 25 src/http/ProxyTunnel.rs 0 0 25 src/http_jsc/websocket_client/WebSocketProxyTunnel.rs 0 0 25 src/runtime/socket/UpgradedDuplex.rs 1 2 25 src/runtime/socket/WindowsNamedPipe.rs 1 0 25 src/runtime/socket/WindowsNamedPipeContext.rs 1 0 25 src/runtime/socket/socket_body.rs 3 5 25 src/uws/lib.rs 6 7 25 test/js/node/tls/node-tls-connect.test.ts 8 4 25 ``` </details>  --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

robobun · 2026-09-11T13:12:10Z

#42324 is stacked on this branch. It covers the second SSL_read driver (SSLWrapper in src/uws/lib.rs: TLS over a Duplex, a Windows named pipe, the http2 raw-socket upgrade) and reuses TLSSocket::on_ssl_error from here. It moves the inline error picker in us_internal_ssl_on_data into us_ssl_take_fatal_error() so both drivers call one function. No other line of this PR changes.

robobun · 2026-09-26T21:40:05Z

#42324 no longer stacks on this branch. It now targets main, because this branch does not merge there today: text conflicts in packages/bun-usockets/src/internal/internal.h and test/js/node/tls/node-tls-server.test.ts, and NewSocket::on_ssl_error needs bun_event_loop::ContextId::NONE as the first argument of run_callback. #42324 carries the same on_ssl_error and the same two tlsFatal branches in net.ts, and adds us_ssl_take_fatal_error() to openssl.c (the picker this PR has inline in us_internal_ssl_on_data). After a rebase this PR can call that helper and drop the shared hunks. It can also flip the two it.failing rows for plain tls.connect in test/js/node/tls/node-tls-connect.test.ts, which record that the uSockets engine does not report the error yet.

Jarred-Sumner · 2026-10-06T06:19:01Z

Superseded by #44618, which consolidates the open TLS pull requests. This fix and its tests are in there, either as written, rewritten smaller, or merged with the other PRs that patched the same cause (see the "By area" list in that PR). Closing in favor of it.

…41272, #42324, #44223) A record that does not decrypt, a fatal alert that arrives after the handshake (TLS 1.3 certificate_required) and a refused renegotiation all ended as a clean 'end' with no error. The fd engine also dropped the data it had decrypted earlier in the same read, SSLWrapper never sent its own alert, and a refused renegotiation was reported as one more handshake with the session's X509 verdict, which node:tls read as another 'secureConnect'. Both engines keep their one report. on_handshake(0, EPROTO + reason) now means a TLS protocol failure at any time, not only in the first handshake. At the fatal exit of the read loop each engine takes the reason before any JS runs, reports a handshake that this read finished, delivers parked events and the data decrypted so far, tells the owner, and then closes the connection itself: no owner has to react for the session to end. - A refusal falls into that exit. Past the limit the engine turns renegotiation off and lets BoringSSL refuse, so there is one identity, NO_RENEGOTIATION. After our own close_notify a request has no answer and is not an error. - us_ssl_take_error_reason() is the one place that picks the reason, for both engines and for the first handshake too. - NewSocket: once a handshake was reported, a failure goes to the `error` handler and never to `handshake` or `open`. With no `error` handler the socket only closes: a peer cannot raise an uncaught exception. - node:tls emits it like Node's onerror and keeps the socket, so the native close gives 'error', 'end', 'close' and a paused reader keeps its data.

…ps, WebSocket, SQL) (#44618) ### What does this PR do? Consolidates the open TLS pull requests into one. Each was reproduced on `main` and, for `node:*` behavior, on Node v26.3.0 first. About a third are ported as written, the rest are rewritten smaller or merged into one fix where several PRs patched the same cause. One commit per fix, so it can be read commit by commit. Fixes #43520, fixes #31396, fixes #43635, fixes #37193, fixes #43846, fixes #17932, fixes #41061, fixes #36887, fixes #31810, fixes #35240, fixes #32234, fixes #44365, fixes #43807, fixes #42280, fixes #44517. Addresses #41856 (SNI and `servername`; not `checkServerIdentity` for SQL), #24845 (the spin is gone, shown with fault injection on Linux; not run on macOS), #19754 (node-fetch forwards the agent's TLS options; the Kubernetes client itself was not run). #### The ones that matter most | | On `main` | PRs | |---|---|---| | Client certificate disclosure | `https.request()` with a client certificate sends it to a server it then refuses (wrong name, `checkServerIdentity`, `destroy()` in `'secureConnect'`, `terminate()` in `handshake`). A server can force it with a junk record behind its Finished | #43946 | | False `authorized` | Over a Duplex, `secureConnect` with `authorized === true` for a peer that failed the key proof; `secureConnect` for a plaintext peer with `rejectUnauthorized: false` | #44422, #32929 | | Cleartext https | `https.createServer()` without a usable key/cert answers plain HTTP | #41672, #33539 | | Revoked client certificates | An https mTLS server never sees `crl`, so a revoked client is `authorized` | #41641 | | Pooled sockets | Requests with different client certificates or CAs share an `https.Agent` socket and session | #42498 | | Silent plaintext | `tls: [...]` given to `Bun.listen` / `Bun.connect` is plain TCP | #41490 | | Server weakened by a client knob | `NODE_TLS_REJECT_UNAUTHORIZED=0` turns off a server's client-certificate enforcement | #35245 | | Pins never checked | `WebSocket` never calls `tls.checkServerIdentity` and ignores `tls.serverName` | #41648 | | `verify-full` dropped | `PGSSLMODE=verify-*` is lost next to a `TLS_*` URL variable; `tls: true` sends no SNI | #44498 | | Crashes | use-after-free from `destroy()` in `ALPNCallback` over a Duplex; `abort()` on a late `setSession()`; SIGABRT in `fetch` with an https proxy from the environment and a `Bun.file()` body | #44462, #41671, #44458 | | Stream corruption | A TLS `write()` can lose 16 KiB it reported as written while another socket on the loop is stalled | #44529 | | Hangs and spins | 100% CPU on a failing `send()`; a fatal `SSL_write` leaves the socket open forever; `idleTimeout` never sheds a TLS client that ignores `close_notify` | #34510, #38176, #42336 | | Wrong certificate (regression since 1.3.14) | Connections accepted before `stop()` / `close()` get the default certificate and skip their entry's `requestCert` / `ca` | #42355 | | Quadratic Duplex / proxy tunnel | Reading one chunk over a Duplex, CPU: 8 MB 0.88 s → 0.14 s, 16 MB 3.18 s → 0.23 s, 32 MB 11.75 s → 0.39 s; `fetch` upload through CONNECT: 1.7 s → 0.18 s (debug build) | #44464 | #### By area - **fd engine, write path** (`openssl.c`, `socket.c`): #42352, #34510 + #38176 + #42336 as one change, #44529, #44458, #44192. A rejected `send()` ends the write side only and closes at the next writable event unless the peer's bytes are still queued (a 413 sent before a reset is still read). No new per-socket state. Also, on kqueue, **a FIN no longer ends a socket that waits in the low-priority queue** (`loop.c`): with more than 5 TLS handshakes at once, a client that ended right after its handshake could be reset and its server socket report `socket hang up`, because the eof that the sentinel read knote reports was acted on ahead of the unread Finished. That is on `main` too (the macOS entry for `node-tls-server.test.ts` in `test/flaky-tests.txt`: 7 of 48 recent builds of other branches), and this branch made it likelier (6 of 8 builds), since Finished now leaves in one segment with the close_notify. - **Error reporting, both engines**: #44422, #32929, #44516, #37094, #41272 + #42324 + #44223 as one change, #44021, #37472, #43946, #33630. One channel: a fatal error on an established session is reported, then **the engine closes the connection itself**, whatever the owner does with the report. `test/js/bun/net/tls-fatal-error-closes.test.ts` asserts closed-and-nothing-delivered for every owner (node:tls, `Bun.connect`, `Bun.listen`, `fetch` direct and through CONNECT, `Bun.serve`, `WebSocket` direct and through a proxy, Postgres, MySQL, Valkey, Duplex). - **Duplex engine** (`SSLWrapper`, `UpgradedDuplex`): #44462, #43529, #42332, #44464. #43877 + #44394 were in and are **out again**, see "Worth a look" 5. - **node:tls wrap lifecycle** (`net.ts`, `tls.ts`): #38007, #38058, #38028 + #38122 + #38076 as one change (six copies of the attach code become two helpers), #38311, #39008, #38154, #42340 + #42343 + #42339 + #42453 as one change, #43791, #42425, #44085, #42683, #39088, #39040, #40375, and what was still real of #36534. - **SNI, ALPN, server contexts**: #43080, #42050, #37195 + #43849 as one change (**one** SNI matcher for TCP and HTTP/3), #42355, #42285, #33253, part of #37896, part of #37013. A `tls.Server` has one `SSL_CTX`. - **Verification and options**: #44738, #41490, #37005 + the cwd pin of #40984, #31811, #43982, #33483 + #35245, #41810, #32235, #44441, #38092. - **node:tls API and CA store**: #41671, #38145, #32824, #43594, #39997, #41696, #33534, #34748, #42991, #42996, #42970. - **node:https, Agent, `ws`, node-fetch**: #41672 (https half), #41641, #38261, #42498, #44346, #35609, #31397, #42325. - **WebSocket client**: #41648, #37487 + #43048 as one change. - **SQL, Redis**: #33666, #41711, #44498, part of #42054. - **Tests only**: #41426, #40040, #44395, #44016, #37860, #40591, #44440, #41424. Found on the way and fixed here: an upload that a TLS 1.2 server interrupts with a renegotiation never completes on `main` (0 of 32 runs over `https.request`, `fetch`, `node:tls` and `Bun.connect`: the renegotiation ClientHello lands inside an application record that is still unsent, or the socket gets no `drain` again) and completes here, with two tests from robobun; the fix for #40653 (final flight and first write in one segment) stopped working whenever another TLS socket on the loop was stalled, on `main` too; the `tls.Server` prototype pinned the last server constructed and every `SSL_CTX` it owned; `Object.create(process.env).NODE_TLS_REJECT_UNAUTHORIZED = "0"` turned verification off process-wide once a `SHARE_ENV` worker existed; two debug panics when wrapping a shut-down or still-connecting socket; a `fetch` POST through a proxy sent its headers twice when the origin renegotiated; `BlockList` ignored IPv6 zone ids; a test now ties `root_certs.der` to `certdata.txt`. #### Behavior changes - **A server's `ca` without `requestCert` no longer asks for a client certificate** (`Bun.serve`, `Bun.listen`, HTTP/3, node:tls). It matches the docs and Node. On `main` such a server refused clients with no certificate but served any unrelated self-signed one, so it was never authentication. **Set `requestCert: true` to require a certificate.** A matrix test pins that `requestCert: true` still refuses no certificate and an untrusted one on 8 kinds of server, TLS 1.2 and 1.3, with `NODE_TLS_REJECT_UNAUTHORIZED` unset and `0`. - `NODE_TLS_REJECT_UNAUTHORIZED=0` no longer relaxes a server. - `Bun.connect` / `Bun.listen` hear of a fatal TLS error after the handshake through `error(socket, err)`. With no `error` handler the socket just closes. - HTTP/3 server names match like TCP: `*.` covers exactly one label, case is ignored, a trailing dot is ignored, the last registration of a name wins. - `requestCert` on node:https is `=== true`, as in Node. - An array where a generated options dictionary is expected throws (`tls: []`, `jest.useFakeTimers([])`). - `key` / `cert` arrays serve every identity. A client that can use both gets ECDSA, where `main` served whichever pair came last. - `ecdhCurve` is forwarded by node:https, `ws` and node-fetch now, so a group BoringSSL lacks (`X448`) throws there as it already does in `tls.createServer`. - A wrapped socket's error is re-emitted on the TLS socket as in Node, so `raw.destroy(err)` with a listener on `raw` only is uncaught, as in Node. - `sql.options.tls` is always an object, never `true`. `RedisClient` sends SNI. - `tls: { secureContext }` alone asks for TLS on `Bun.listen` / `Bun.connect` (it was plain TCP), and a value that is not a `SecureContext` throws. The context is served as it is: the `requestCert` / `rejectUnauthorized` it was created with hold whatever the options next to it say, and `requestCert` in the options over a context that does not ask throws at `listen()`. - `tls.DEFAULT_CIPHERS` reaches every client once assigned (`fetch`, `WebSocket`, `Bun.connect`, `RedisClient`, `Bun.SQL`, `S3Client`, proxy tunnels) and servers again. A list that selects no cipher throws `ERR_SSL_NO_CIPHER_MATCH` at the assignment. `fetch.preconnect()` dials nothing after an assignment. - The warning for an unreadable `NODE_EXTRA_CA_CERTS` is Node's one line, without the `warn:` prefix. - `BUN_CONFIG_WS_CLOSE_TIMEOUT` (default 30 s): how long a `WebSocket` client waits for the server to close the connection after the closing handshake. #### Worth a look in review 1. **#44529**: the kernel-refused remainder of a TLS write moves from the loop's one slot onto the connection (in the existing rare struct), so the write BIO never refuses a sealed record. Nothing is allocated on an unstalled path (200 writes: 0 appends, same `send()` count as `main`), memory with 16 stalled writers is lower than on `main` (276 KB vs 340 KB, which `main` holds inside BoringSSL's buffers), `us_socket_t` stays 80 bytes. It needs a bound on how long a deferred close waits, or a peer that stops reading pins the fd past `destroy()`: `US_SSL_CLOSE_AFTER_SPILL_TIMEOUT` is a fixed 10 s, not re-armed on progress. Separate commits, but the fix that keeps the client certificate off the wire beside a stalled socket builds on them. 2. **The default name check of node:tls also runs inside the handshake**, so a wrong-name server gets no client certificate on TLS 1.2 either. JS still runs it after every successful handshake, so a difference between the two matchers can only refuse. Error objects are byte-identical. 3. **#44441** widens trust by design: a self-issued leaf whose `keyUsage` lacks `keyCertSign` (`dotnet dev-certs`) is its own anchor when the store holds a byte-identical copy. No BoringSSL change. Expired pin, same subject with another key, wrong EKU and a pinned intermediate are tested to fail. 4. **#32235** only adds Ed25519 and ECDSA P-521 to the verify list. A captured ClientHello shows `main`'s list with the two inserted; `rsa_pkcs1_sha1` stays. 5. **A stream that a TLS socket wraps, when that TLS socket closes.** An earlier state of this branch lost data here while CI was green (found by #44709's report): with the peer closing first, 4 of 8 MiB arrived with TLS in TLS, 4 of 32 MiB on the http2 `emit("connection")` path, and a `write()` with no `'error'` listener ended the process. Three Node-parity changes only hold together: destroying the wrapped stream at the close (#38028 + #38122 + #38076, #38154) is safe only if every write has really completed (#43877), which in turn needs Node's handling of the peer's close_notify, which needs half-open sockets that the GC can collect. So: - #43877 + #44394 are reverted and reopened. A write over a stream completes once the stream has taken the ciphertext, as on `main`. - Until the verdict on the peer lets the session through, the application cannot have written over it. There the wrapped stream is destroyed as in Node, with the sessions below it. That keeps the release of the connection after a failed handshake, a rejected certificate and an early `destroy()`. The same for an http2 socket the application never got, and for `resetAndDestroy()`. - After that it is `main`'s teardown: a `net.Socket` only gets the engine's `end()`, closes at its peer's FIN, keeps its own timeout and reports its own errors. Any other stream is destroyed with the TLS socket. The regular suites cannot see any of this (999 files were green on every broken variant), so it was steered by eleven seeded differential fuzzers run on this build, `main`, Node v26.3.0 and the earlier state: close, `end()`, `destroy()`, `destroySoon()`, resets, hung and half-open peers, paused writers, timeouts, two and three sessions deep, over TCP and over Duplexes, before, at and after the handshake, and http2 requests. See "How did you verify". #### Known limits - `fetch` with a `checkServerIdentity` function still sends the client certificate (not the request) to a server the function refuses. On TLS 1.2 any verdict a JS callback gives is too late, as in Node. - `addContext()` / `SNICallback` still do not apply to a server-side socket on the stream engine (`emit("connection", duplex)`, TLS in TLS, unflushed writes, named pipes), as on `main`. - A CA bundled in a pfx extends an explicit `ca` only, for `ws` / node-fetch / `WebSocket`: the native `ca` can only replace the default store, and that store keeps `SSL_CERT_FILE` / `SSL_CERT_DIR`. - P-521 leaves work on TLS 1.3 only. TLS 1.2 needs secp521r1 in every ClientHello (`it.todo`). - Once `tls.DEFAULT_CIPHERS` is assigned, `fetch(url, { protocol: "http3" })` is `HTTP3Unsupported`, as with an explicit `ciphers`. - `addCACert()` by hand does not extend the chains of a context with several identities. - A throwing `ALPNCallback` sends `no_application_protocol` on both engines. Node sends nothing and its client sees `ECONNRESET`. - TLS in TLS, peer FIN while the outer handshake runs: the inner socket gets one `write EPIPE`, where Node gives `ECONNRESET` (`main` gives it no error at all). - `@SECLEVEL` in `ciphers` is dropped by the `ws` / node-fetch shims, which used to ignore `ciphers`. node:tls keeps throwing `ERR_SSL_INVALID_COMMAND`. - Beside a stalled TLS socket only the first record (16 KiB) of the first write leaves with the handshake flight. The rest goes record by record, which is what bounds the memory of stalled writers. - After a fatal error on an established session the socket emits `'error'` and then `'close'`. Node emits `'error'` and leaves the socket open. - A paused reader whose own write the kernel rejects loses what it had not read yet, with an `EPIPE`, as on Node. `main` reports no error there and delivers it. - On `main` too: a `Bun.listen` socket without `allowHalfOpen` that has unsent ciphertext when the client's `shutdown()` arrives loses that ciphertext (32 KiB), and over plain TCP `end()` with the peer still sending is a close over unread input, so a reset. - Differences from both `main` and Node that the differential runs below found and that stay, all with a peer that aborts: `ECONNRESET` instead of a clean `'end'` after the socket's own `'finish'` when the peer destroyed with unread data; under TLS 1.2, a zero-length `write()` followed by `destroy()` in `'secureConnection'` leaves the client without `'secureConnect'` (a plain `destroy()` there matches Node); a TLS 1.2 client that destroys in `'secureConnect'` gets no `'session'`; a `ClientRequest` whose handshake fails with an alert emits `'error'` and `'close'` but no `'finish'` (`writableFinished` is true). - Once `tls.DEFAULT_CIPHERS` is assigned, `fetch.preconnect()` opens nothing: `fetch()` then uses a context of its own, and a socket warmed under the default one would never be picked up. - A TLS `send()` that the kernel refuses outside a `write()` call (the drain of unsent ciphertext) is reported with the close, as `read EPIPE` / `read ECONNRESET`. Node says `write EPIPE`. `main` does not report it at all. - Once the application has a session over a `net.Socket` (TLS in TLS, http2 `emit("connection")`), a peer that never sends its FIN holds that socket after the TLS socket closed, as on `main`. Node destroys it. Two tests of #38154 are `todo` for this. Closing it any earlier (at its `'finish'`, say) makes the kernel drop what it has not sent yet as soon as the peer's close_notify arrives. - Plaintext that was queued on a socket before it was wrapped (STARTTLS with a backlog) is dropped when the TLS socket is destroyed, or its handshake fails, before the session is accepted. Node drops it too, except on `destroySoon()`. `main` sends it. - Over a stream that is no `net.Socket`, `end()` can still cut what that stream has buffered, and there is no backpressure, both as on `main` (#43877). - `tls.secureContext` (the undocumented door node:tls uses) is not read by a Windows named pipe listener, which builds its context from the options. On `upgradeTLS({ isServer: true })` the options next to it are the policy, as with Node's `SetVerifyMode`. - `selectServerName()` rebuilds the name tree per ClientHello for injected sockets of a server with `addContext()` entries: 0.4 µs for 1 entry, 3.7 µs for 10, 41 µs for 100, against 631–1111 µs for a handshake. #### Not included Left open, because they need a decision or are not TLS: #43877 + #44394 (see "Worth a look" 5; #43874 stays open with them), #38548, #38591 (both shrink who is trusted), #41589 (`verify-full` vs `NODE_TLS_REJECT_UNAUTHORIZED=0`), #37197, #41706, #43216, #33487, #33545, #36707, #32435, #37255, #28691, #40275, #30314 (features), #38120 (needs the BoringSSL fork, as did #33517, which the stale bot has closed since), #38529 (needs a Windows measurement), #34342, #38232, #43089, #44454, #40451, #42710, #44527, #38088, #38093, #41898. #37896, #42054 and #37013 stay open for the halves not taken. `http.createServer({ key, cert })` keeps serving TLS on purpose. One open question: `tls: {}` (an object that names no TLS option) is plain TCP on `Bun.listen` / `Bun.connect`, here and on `main`. It is the same trap as `tls: []`, but changing it changes a Bun default, so it is left alone. ### How did you verify your code works? - Every new test fails on `main` for the stated reason and passes here, except guards that pin existing behavior, each shown to fail when its clause is removed. `node:*` tests also pass on Node v26.3.0; the few that cannot say which Node version has the behavior. - 212 test files that touch TLS, sockets, http, http2, fetch, WebSocket, SQL, Valkey and workers: 6154 pass, 2 fail. Both are seen on `main` too: `serve.test.ts` "root range port" (the box runs as root), and `worker_threads.test.ts` "terminate(): nothing of the worker's runs after the request", which is flaky there and passed in the run below. - 58 of those files the way the ASAN lane runs them (LeakSanitizer + `BUN_JSC_validateExceptionChecks`): 58 files, 48 of them with leak checking, 4132 pass, 3 fail. All three also fail on `main`: `serve.test.ts` "root range port", `node-net.test.ts` "should not leak when connect({path}) fails synchronously on a reused handle" (times out under this environment), `worker_threads.test.ts` "process.exit() with a shell cp in flight" (a `ShellCpTask` leak). - 647 vendored `test-tls-*`, `test-https-*`, `test-net-*`, `test-http2-*`: the only two failures also fail on `main`. - The SNI matcher was diffed against both old matchers: 3 seeds × 1.23 M lookups × 3 registration flavours, every difference in one of the intended classes, TCP and HTTP/3 identical on every lookup. - The headline rows were also driven by hand with scripts against this build, `main` and Node v26.3.0: cleartext https, `crl`, `tls: []` / `{ secureContext }`, the `ca` / `requestCert` matrix, the client certificate on a wrong-name server, late `setSession()`, `destroy()` in `ALPNCallback`, `[rsa, ec]` identities with an intermediate from `ca`, `WebSocket` `checkServerIdentity`, a corrupted record, the Duplex read above, `tls.DEFAULT_CIPHERS`. - The `setSession()` guard was checked against the real `abort()` at 43 handshake states. - `bun run rust:check-all`: 12 of 12 targets. `tsc`, oxlint, source lints, prettier, rustfmt, mordant clean. - usockets' `_Nonnull` is compiled out of debug builds, so 105 of those files were also run on a local release ASAN build with the CI runner's environment (92 with leak checking): 4595 pass, 1 fail, `child_process.test.ts` "spawn reports EPERM after dropping privileges", which cannot pass as root and fails on `main` too. - The close of a TLS socket over another stream ("Worth a look" 5): eleven seeded differential fuzzers, 8,424 scenarios compared, each run on a release ASAN build of this branch, on `main`, on Node v26.3.0 and on the earlier state of the branch. Against `main`: - Data that `main` delivers in full is cut in 5 scenarios, and about 150 that `main` cuts arrive in full. Of the 5, in 2 `main` never notices the peer's close and keeps the socket for good, 2 call `end()` on the middle one of three sessions over an in-memory Duplex, and 1 does the same on Node. - No dead timeout, no silent reset and no uncaught error that `main` does not have (4 uncaught errors fewer). - A socket stays open where `main` closes it in 109, and closes where `main` keeps it in 295. 92 of the 109 do the same on Node or on the earlier state (a `destroy()` that an in-memory Duplex does not show its peer, half-open peers). 14 wait for a peer that paused reading and so does not read the FIN (#42332's backpressure, as in Node); the socket's own timeout fires there. 3 are left: one on a 5 ms timer, two with three sessions over an in-memory Duplex. - The earlier state of the branch cut data in 173 of the 400 scenarios of one of them, where `main` cuts none and this cuts none. - 23 new tests pin what they found. Each earlier attempt at this fix fails the ones that describe it, the earlier state of the branch fails 7, and all pass on Node. - After that change: 999 test files on the release ASAN build (20,246 pass; the 11 files that fail need a database, Docker, DNS or a non-root user, or share a temp directory with a parallel run and pass alone), 61 on the debug build. - TLS over a file descriptor (`openssl.c`, the path of `fetch`, `Bun.serve`, `tls.connect`, `Bun.connect`) got the same treatment after the rebase: seeded differential fuzzers on CI's release build of this branch, on `main` and, for `node:*`, on Node v26.3.0. Every runtime also against itself for the noise floor, injected faults and known bugs of `main` as positive controls, and a difference counts only if it shows in 5 of 5 fresh processes. - `node:tls` over TCP: 11,500 scenarios (one connection with Node as the oracle line by line; 2 to 60 connections beside stalled neighbours; raw peers that break the handshake). HTTPS: about 136,000 runs over `Bun.serve` + `fetch`, `node:https`, `node:http2` and `wss://`, also with the two ends in different runtimes. `Bun.connect` / `Bun.listen` / `upgradeTLS`: 11,500 scenarios and 720 slow connections, with writers driven by what `write()` returns, beside up to 6 stalled, dripping, closing or resetting neighbours, and plain TCP as a second oracle. No crash, hang, duplication, reordering or silent truncation, and no change in time or in connection reuse. - They found six things that `main` does better, none of which any test showed. All are fixed, each with a test that fails on the build before: what the peer sent lost behind a rejected `send()` (23 scenarios, and an early HTTPS response lost with only `EPIPE`), the same silently for a paused reader, `server.close()` never calling back on a half-open server after a ClientHello and a reset (17), `closeAllConnections()` taking 12 s with a stalled client, `end()` losing up to 1.3 of 4 MiB that `write()` had reported while the peer still uploads, and `end()` a little after a stall never closing beside other stalled TLS sockets. The last two fixes also deliver the 1 to 2 MiB that `main` loses there, and close the socket that `main` keeps for good without such neighbours. - All of them again after every fix, on CI's release build of it. That caught one regression of a fix itself (a reader stopped for backpressure lost 86,385 bytes, 1 of 6,000 scenarios), fixed too. On the last build: scenarios that lose data where `main` does not 23 → 2, and Node loses it in both, with the same `EPIPE`; `server.close()` that never calls back 17 → 0; connections held 4 → 0; requests that end in an error only where `main` has a response 6 → 0. With a Node server in another process, a request ends in an error only in 8 and 10 of 1,500 scenarios here, 5 and 3 on `main`, 10 with Node as the client. - `Bun.connect` / `Bun.listen` on the last build against `main`, in scenarios: hangs 0 against 1,031, sockets and fds never released 0 against 965, corrupted data 0 against 345, `abort()` 0 against 26 (`setSession()` after the handshake), writers that never close 0 against 101 of 720 connections. No kind of failure shows here and not on `main`. About a third of the slow connections close later than on `main`, in 1 to 16 s instead of at once, waiting for unsent ciphertext or for the peer's close_notify, and 79 more of them deliver all that `write()` reported. RSS and time with 16 to 256 stalled writers are the same. - What they found that `main` does worse: a `WebSocket` that calls `close()` with sends pending loses messages in 81 of 999 scenarios (0 here), 37 server sockets left open, 10 `server.close()` that never call back, 20 write callbacks that never run. - The kqueue fix cannot be run on Linux. The `connectionListener` count test now says what became of a missing connection, which is how the cause was found (`'tlsClientError'` "socket hang up", then `read ECONNRESET` at the client of the same port, after its `'secureConnect'`). On macOS x64 it failed every attempt of the three builds before the fix and passed at the first attempt of the build with it. - Windows and macOS were only run by CI. Four new tests asserted what only the Linux kernel does (a FIN read ahead of a reset, unread bytes surviving a reset, loopback buffer sizes, `fstat()` on a socket) and now say so per platform. --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> Co-authored-by: robobun <117481402+robobun@users.noreply.github.com>

robobun assigned Jarred-Sumner Sep 3, 2026

github-actions Bot added the claude label Sep 3, 2026

robobun mentioned this pull request Sep 3, 2026

tls: report a fatal TLS alert received after the handshake completes #33294

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coderabbitai Bot reviewed Sep 3, 2026

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Comment thread src/runtime/socket/socket_body.rs Resolved

Comment thread test/js/node/tls/node-tls-cert.test.ts Resolved

test: shorten the comment on the TLS 1.3 client certificate case

76d70f2