fix(l1): reject non-canonical single-byte RLP in u8 decoding#6958
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kevaundray wants to merge 1 commit into
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fix(l1): reject non-canonical single-byte RLP in u8 decoding#6958kevaundray wants to merge 1 commit into
kevaundray wants to merge 1 commit into
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**Motivation** Canonical RLP requires a single byte in 0x00..=0x7f to be its own encoding; wrapping it in a 1-byte string is non-canonical. lambdaclass#6818 made decode_rlp_item reject this, but the hand-rolled u8 fast path skips those checks, so u8::decode accepted [0x81, 0x01] -> 1 and [0x81, 0x00] -> 0 while u16/u32/u64 reject the same bytes. **Description** Reject a wrapped second byte below 0x80 in the u8 two-byte arm, matching the canonicality rules the general decode path already enforces, and add a regression test.
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Generated by claude: I was experimenting with FV and it spotted this.
Motivation
Canonical RLP requires a single byte in 0x00..=0x7f to be its own encoding; wrapping it in a 1-byte string is non-canonical. #6818 made decode_rlp_item reject this, but the hand-rolled u8 fast path skips those checks, so u8::decode accepted [0x81, 0x01] -> 1 and [0x81, 0x00] -> 0 while u16/u32/u64 reject the same bytes.
Description
Reject a wrapped second byte below 0x80 in the u8 two-byte arm, matching the canonicality rules the general decode path already enforces, and add a regression test.
Checklist
STORE_SCHEMA_VERSION(crates/storage/lib.rs) if the PR includes breaking changes to theStorerequiring a re-sync.Closes #issue_number