ConstReadonlyPRIVATE_KEY: 256Read-only for owner only (0o400) - Use for private keys
ReadonlyPUBLIC_DOC: 292Read-only for everyone (0o444) - Use for certificates, CSRs, public keys
ReadonlyOWNER_RW: 384Temporary owner read/write (0o600) - Use to unlock read-only files before deletion
Standard file permissions for PKI files. Use these to ensure consistent security across the codebase.