fix(fqdn): enforce maximum DNS name length - #1603
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matheusgb
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July 21, 2026 19:03
nodivbyzero
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Jul 22, 2026
zemzale
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Jul 29, 2026
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Fixes Or Enhances
Fixes #1602.
The
fqdnvalidator limited each individual label to 63 characters but did not enforce the 255-octet DNS wire-format limit for the complete name. As a result, syntactically valid labels could be repeated until the resulting domain exceeded the maximum DNS name length.This change rejects FQDNs whose presentation form exceeds 253 characters, excluding the optional trailing root dot. It preserves support for a 254-character absolute FQDN when the final character is the root dot.
Boundary tests cover valid and invalid names both with and without the trailing dot.
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