把 CSR（证书签发请求）粘贴进来，立刻看到它的主体、SAN、公钥、签名算法和指纹，并验证自签名是否有效；还能顺手核对一把私钥是否与这个 CSR 配对。Paste a CSR (Certificate Signing Request) to inspect its subject, SAN, public key, signature algorithm and fingerprint, verify its self-signature, and check whether a private key matches it.
签发证书前先解码检查 CSR 是个好习惯：重点看 SAN 是否写全（漏了域名/IP 签出来的证书就不能用）、CN 是否正确。自签名验证通过，说明 CSR 在生成后没有被改动过。Decoding a CSR before issuance is a good habit: check the SAN list is complete (a missing domain or IP means the issued certificate will not work for it) and the CN is right. A valid self-signature shows the CSR was not altered after generation.