DNSSEC记录验证与链路信任（DS/DNSKEY/RRSIG）最佳实践

背景与价值DNSSEC可防止解析结果被篡改。基础结构与算法校验配合链路信任策略，有助于提升解析安全。统一规范算法限定：仅接受安全算法（如 `RSASHA256`、`ECDSAP256SHA256`）。结构校验：DS/DNSKEY/RRSIG等记录的字段格式必须合法。失败阻断：校验失败时拒绝使用解析结果。核心实现记录结构校验（示意）type DS = { keyTag: number; algorithm: string; digestType: string; digest: string } type DNSKEY = { flags: number; protocol: number; algorithm: string; publicKey: string } type RRSIG = { typeCovered: string; algorithm: string; labels: number; originalTtl: number; expiration: number; inception: number; keyTag: number; signerName: string; signature: string } const allowAlgo = new Set(['RSASHA256','ECDSAP256SHA256']) function validHex(s: string): boolean { return /^[a-f0-9]+$/i.test(s) } function validB64(s: string): boolean { return /^[A-Za-z0-9+/=]+$/.test(s) } function dsOk(ds: DS): boolean { return Number.isInteger(ds.keyTag) && allowAlgo.has(ds.algorithm) && validHex(ds.digest) } function dnskeyOk(k: DNSKEY): boolean { return k.protocol === 3 && allowAlgo.has(k.algorithm) && validB64(k.publicKey) } function rrsigOk(r: RRSIG): boolean { return allowAlgo.has(r.algorithm) && Number.isInteger(r.labels) && Number.isInteger(r.originalTtl) && Number.isInteger(r.expiration) && Number.isInteger(r.inception) && Number.isInteger(r.keyTag) && validB64(r.signature) } 链路信任（简化）function withinWindow(exp: number, inc: number): boolean { const now = Math.floor(Date.now()/1000); return inc <= now && now <= exp } function trust(ds: DS, key: DNSKEY, sig: RRSIG): boolean { return dsOk(ds) && dnskeyOk(key) && rrsigOk(sig) && withinWindow(sig.expiration, sig.inception) } 落地建议对关键记录进行结构与算法校验，并在过期窗口内验证签名有效期。失败立即阻断使用解析结果并进行审计，必要时回退备用解析通道。验证清单记录是否命中允许算法并结构合法；签名时间窗口是否有效。