fix(web-bot-auth): fail closed on future created timestamps in Rust verify - #127
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AkshatM merged 2 commits intoAug 18, 2026
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…erify WebBotAuthVerifier::verify already rejects expired signatures after cloudflare#125, but still accepted cryptographically valid signatures with created in the future. The TypeScript web-bot-auth verifier rejects those before crypto verify. Enforce the created window the same way, before expires, and surface SignatureCreatedInFuture. verify_ignore_expiry still runs crypto and reports the new advisory flag.
AkshatM
reviewed
Aug 14, 2026
| /// the message expired in the past. | ||
| pub is_expired: Option<bool>, | ||
| /// If the `created` tag was present on the message, whether or not | ||
| /// `created` is still in the future. |
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nit: remove the word "still"
AkshatM
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Aug 14, 2026
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Dropped "still" from the |
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Summary
WebBotAuthVerifier::verifystill accepted cryptographically valid signatures whencreatedis in the future, even after #125 started failing closed onexpires. The TypeScriptweb-bot-authverifier already rejects those inputs (created in the future) before crypto verify.This makes the Rust Web Bot Auth verifier fail closed on a future (or unparsable)
createdwindow, then on expiry, then proceeds to cryptographic verification only when the window is valid. That matches TypeScriptpackages/web-bot-auth/src/index.ts. GenericMessageVerifier::verifyis unchanged.verify_ignore_expirystill runs crypto and now reportsis_created_in_futureon the advisory.Threat model: an attacker who can mint a valid Ed25519 web-bot-auth signature (stolen bot key, or the bot itself) can set
created=now+skewwithexpiresstill in the future. Rust currently treats that as valid; TypeScript rejects it. Same authority assumption as #125 for expiry.Test plan
cargo +stable test --all --all-features(including newtest_verify_rejects_created_in_the_future)cargo +stable clippy --all-features --all-targets -- -D warningscargo +stable fmt --all -- --checkcreatedguard makestest_verify_rejects_created_in_the_futurefail (Ok(SignatureTiming)instead ofSignatureCreatedInFuture)Made with Cursor