Normalize NUL bytes to U+FFFD at parse entry#248
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A raw NUL (U+0000) must never reach rendered output. Replace it with the
U+FFFD replacement character at the parse entry (WHATWG-style, decided
cross-impl behavior), so a control byte cannot survive into HTML.
SafeMode now also strips U+FFFD from a URL scheme, so a `java\x00script:`
evasion - which arrives as `java\u{FFFD}script:` after normalization - is
still detected and blocked (empty href).
Ported from carve-php commit ff40264.
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## master #248 +/- ##
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Coverage 92.06% 92.06%
- Complexity 3571 3572 +1
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Files 107 107
Lines 10118 10120 +2
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+ Hits 9315 9317 +2
Misses 803 803 ☔ View full report in Codecov by Harness. 🚀 New features to boost your workflow:
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A raw NUL (U+0000) must never reach rendered output. This replaces it with the U+FFFD replacement character at the parse entry (WHATWG-style normalization, for cross-impl conformance), so a control byte cannot survive into the produced HTML.
What changed
BlockParser: at the parse entry, any NUL in the input is replaced with U+FFFD before line splitting.SafeMode: the URL-scheme normalization now also strips the U+FFFD replacement character. A NUL-in-scheme evasion such asjava\x00script:arrives asjava\u{FFFD}script:after normalization; stripping U+FFFD keeps that evasion detected and blocked (empty href), preserving the existing SafeMode guarantee.The dangerous-scheme detection regex itself was kept intact; the change only extends the set of stripped characters so the upstream NUL normalization does not open a new bypass.
Ported from carve-php commit ff40264.