Fix HTTP startline validation (#16022)#16025
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normanmaurer merged 1 commit into5.0from Dec 13, 2025
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Motivation: The code assumed that oversized bit shifting would result in zeroing out values due to overflow. However, the Java Language Specification instead says that shifts effectively only consider the lower six bits of the shift amount, resulting in modular-arithmetic shifts. The consequence is that, for instance, shifing by the capital letter 'M' produces the same bit mask as carriage-return '\r', which is an illegal character in an HTTP start line. This incorrectly rejected valid URIs. Modification: Make the shifting conditional and only use it on character values less than or equal to 64 (the Long bit size). Also add tests to check that valid URLs are accepted. Result: Fixes #16020 --------- Co-authored-by: Jonas Konrad <me@yawk.at>
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Motivation:
The code assumed that oversized bit shifting would result in zeroing out values due to overflow. However, the Java Language Specification instead says that shifts effectively only consider the lower six bits of the shift amount, resulting in modular-arithmetic shifts. The consequence is that, for instance, shifing by the capital letter 'M' produces the same bit mask as carriage-return '\r', which is an illegal character in an HTTP start line. This incorrectly rejected valid URIs.
Modification:
Make the shifting conditional and only use it on character values less than or equal to 64 (the Long bit size). Also add tests to check that valid URLs are accepted.
Result:
Fixes #16020