Fix: reject '@' in HTTP header field names per RFC 9110 #12838
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RFC 9110 defines HTTP header field names as tokens, which must not contain '@'. Currently '@' is accepted because of MIME separator handling. This patch ensures ParseRules::is_http_field_name rejects '@', aligning behavior with RFC 9110. This prevents invalid header names from being accepted.
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Pull request overview
This PR fixes HTTP header field name validation to comply with RFC 9110 by rejecting the '@' character. The current implementation incorrectly accepts '@' due to MIME separator handling logic.
Changes:
- Removed the exception that allowed '@' in HTTP header field names
- Updated the validation logic to properly reject all MIME separators including '@'
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| { | ||
| #ifndef COMPILE_PARSE_RULES | ||
| return (parseRulesCType[static_cast<unsigned char>(c)] & is_token_BIT); | ||
| return (parseRulesCType[(unsigned char)c] & is_token_BIT); |
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Changed from static_cast<unsigned char> to C-style cast (unsigned char). C++ best practice is to use static_cast for type safety and clarity. This change appears unrelated to the PR's stated purpose of fixing '@' validation.
Suggested change
| return (parseRulesCType[(unsigned char)c] & is_token_BIT); | |
| return (parseRulesCType[static_cast<unsigned char>(c)] & is_token_BIT); |
bryancall
reviewed
Feb 2, 2026
| { | ||
| #ifndef COMPILE_PARSE_RULES | ||
| return (parseRulesCType[static_cast<unsigned char>(c)] & is_token_BIT); | ||
| return (parseRulesCType[(unsigned char)c] & is_token_BIT); |
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RFC 9110 defines HTTP header field names as tokens, which must not contain '@'.
Currently '@' is accepted because of MIME separator handling.
This patch ensures ParseRules::is_http_field_name rejects '@', aligning behavior with RFC 9110.
This prevents invalid header names from being accepted.