René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`tls.connect()` aborts process on malformed ALPNProtocols instead of throwing an error","articleBody":"### Version\n\nv26.7.0\n\n### Platform\n\n```text\nDarwin MacBook-Pro-2.local 25.0.0 Darwin Kernel Version 25.0.0: Tue Aug  5 22:46:55 PDT 2025; root:xnu-12377.1.6~5/RELEASE_ARM64_T6000 arm64\n(bas\n```\n\n### Subsystem\n\n_No response_\n\n### What steps will reproduce the bug?\n\nRun the following command:\n\n```bash\nnode -e \"require('node:tls').connect({ host: '127.0.0.1', port: 9999, ALPNProtocols: [''] })\"\n````\n\nThe process aborts with SIGABRT.\n\nThe same issue can be reproduced with malformed ALPN wire format buffers:\n\n```js\nBuffer.from([0])\nBuffer.from([2, 0x61])\nBuffer.from([1, 0x61, 0x62])\n```\n\npassed as `ALPNProtocols`.\n\n### How often does it reproduce? Is there a required condition?\n\nIt reproduces consistently (100% of the time).\n\nRequired condition:\n\n* Node.js TLS client API is used through `tls.connect()`;\n* `ALPNProtocols` contains an invalid ALPN protocol list;\n* The invalid input reaches the native TLS implementation.\n\nNo network interaction is required.\n\n### What is the expected behavior? Why is that the expected behavior?\n\nThe expected behavior is that Node.js rejects the invalid input by throwing a JavaScript exception (for example `ERR_INVALID_ARG_VALUE`) instead of terminating the process.\n\n`ALPNProtocols` is a documented API option supporting string arrays and Buffer/Uint8Array inputs. Invalid values should be handled as invalid arguments and remain recoverable application errors.\n\n### What do you see instead?\n\nThe entire Node.js process aborts.\n\nThe failure occurs in `TLSWrap::SetALPNProtocols()`:\n\n```cpp\nCHECK_EQ(0, SSL_set_alpn_protos(ssl, protos.data(), protos.length()));\n```\n\nWhen OpenSSL rejects the malformed ALPN list, the CHECK assertion fails and Node exits with SIGABRT (exit code 134).\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/brown-sussy","@type":"Person","name":"brown-sussy"},"datePublished":"2026-08-06T06:02:57Z","url":"https://github.com/nodejs/node/issues/65069"}