fix(pilot-ca): validate beacon hostname to prevent path traversal#3
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issueBeacon previously accepted any non-empty hostname and built the output paths via filepath.Join(outDir, hostname+".crt"). A hostname like "evil/../host" or "../escape" would write the leaf cert + key outside outDir, silently, while still printing success. The leaf cert itself was also malformed (invalid SAN/DNSName). Add a strict DNS-name allowlist regex (lowercase letters, digits, hyphen, dot only — labels <=63 chars, total <=253) and apply it at the very top of issueBeacon, before any filepath.Join touches outDir. Tests: - TestIssueBeacon_HostnameWithSlash_Rejected (renamed from the CurrentBehavior pin) now asserts rejection + that outDir stays empty. - TestIssueBeacon_HostnameWithParentDir_Rejected covers bare "..", "../escape", "foo/../bar", and a Windows-style "evil\\..\\host". - TestIssueBeacon_ValidHostname_Succeeds pins the happy path on a normal multi-label DNS name. All existing tests still pass under -race.
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Summary
issueBeaconaccepted any non-empty hostname and used it directly infilepath.Join(outDir, hostname+".crt"). A hostname likeevil/../hostor../escapewrote the leaf cert + key OUTSIDEoutDirwhile still printing success — a HIGH-severity path-traversal bug.^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?(\.[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?)*$) + 253-char cap, applied at the very top ofissueBeaconbefore anyfilepath.JointouchesoutDir.TestIssueBeacon_HostnameWithSlash_CurrentBehavior(which only logged buggy behavior) toTestIssueBeacon_HostnameWithSlash_Rejectedand flip it to assert rejection + an emptyoutDir. AddTestIssueBeacon_HostnameWithParentDir_Rejected(covers bare..,../escape,foo/../bar,evil\\..\\host) andTestIssueBeacon_ValidHostname_Succeeds(pins the happy path).Test plan
go test -race -count=1 -timeout 120s ./...— passesgo vet ./...— cleangofmt -l .— cleanTestIssueBeacon_*tests pass, including the 3 new/renamed onesTestIssueBeacon_RejectsEmptyHostnamestill passes (the validator preserves the "hostname required" error message for the empty case)