Jon Chery
19b52f6c9b
---ci--- project: orca phase: 24 milestone: v0.12 status: execute ---/ci--- Flock now chmod's the file to 0600 after open (tightens pre-existing looser perms; O_CREATE only sets mode on creation). REQ-139/F15. classifyDialErr + SSH-exec rate limiting documented as v1.x follow-up (the transport is deprecated; SSH-push is the primary). Build green.
41 lines
1.2 KiB
Go
41 lines
1.2 KiB
Go
package security
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import (
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"os"
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"syscall"
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)
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// Flock acquires an exclusive advisory lock on the file at path, creating it
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// if missing. Returns a release function that MUST be called (deferred) to
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// release the lock and close the file descriptor. Used by the known_hosts
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// read-modify-write paths (TOFUHostKeyCallback capture + ResetHostKey) to
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// prevent concurrent writers under v0.9's parallel SSH fan-out (REQ-063,
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// deferred P1 from REVIEW_v0.8 A2).
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func Flock(path string) (release func(), err error) {
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f, err := os.OpenFile(path, os.O_CREATE|os.O_RDWR, 0o600)
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if err != nil {
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return nil, err
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}
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// REQ-139 / F15: tighten pre-existing looser perms to 0600.
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// OpenFile with O_CREATE only sets the mode on creation; if the
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// file already exists with looser perms, they persist. Chmod
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// ensures 0600 regardless.
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_ = os.Chmod(path, 0o600)
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if err := syscall.Flock(int(f.Fd()), syscall.LOCK_EX); err != nil {
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f.Close()
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return nil, err
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}
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return func() {
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_ = syscall.Flock(int(f.Fd()), syscall.LOCK_UN)
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_ = f.Close()
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}, nil
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}
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func tryFlockEx(fd int) error {
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return syscall.Flock(fd, syscall.LOCK_EX|syscall.LOCK_NB)
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}
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func releaseFlock(fd int) error {
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return syscall.Flock(fd, syscall.LOCK_UN)
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}
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