subtle.exportKey(format, key)

• format <string> 必须是 'raw'、'pkcs8'、'spki'、'jwk'、'raw-secret'⁴、'raw-public'⁴ 或 'raw-seed'⁴ 之一。
• key <CryptoKey>
• 返回：<Promise> 成功时会触发一个 <ArrayBuffer> | <Object>。

如果支持，将给定的密钥导出为指定的格式。

🌐 Exports the given key into the specified format, if supported.

如果 <CryptoKey> 无法提取，返回的 Promise 将会被拒绝。

🌐 If the <CryptoKey> is not extractable, the returned promise will reject.

当 format 为 'pkcs8' 或 'spki' 且导出成功时，返回的 promise 将被解析为一个包含导出密钥数据的 <ArrayBuffer>。

🌐 When format is either 'pkcs8' or 'spki' and the export is successful, the returned promise will be resolved with an <ArrayBuffer> containing the exported key data.

当 format 为 'jwk' 且导出成功时，返回的 promise 将会以一个符合 JSON 网钥 规范的 JavaScript 对象来解析。

🌐 When format is 'jwk' and the export is successful, the returned promise will be resolved with a JavaScript object conforming to the JSON Web Key specification.

| 支持的密钥算法 | 'spki' | 'pkcs8' | 'jwk' | 'raw' | 'raw-secret' | 'raw-public' | 'raw-seed' |

| --- | --- | --- | --- | --- | --- | --- | --- |

| 'AES-CBC' | | | ✔ | ✔ | ✔ | | |

| 'AES-CTR' | | | ✔ | ✔ | ✔ | | |

| 'AES-GCM' | | | ✔ | ✔ | ✔ | | |

| 'AES-KW' | | | ✔ | ✔ | ✔ | | |

| 'AES-OCB'⁴ | | | ✔ | | ✔ | | |

| 'ChaCha20-Poly1305'⁴ | | | ✔ | | ✔ | | |

| 'ECDH' | ✔ | ✔ | ✔ | ✔ | | ✔ | |

| 'ECDSA' | ✔ | ✔ | ✔ | ✔ | | ✔ | |

| 'Ed25519' | ✔ | ✔ | ✔ | ✔ | | ✔ | |

| 'Ed448'⁵ | ✔ | ✔ | ✔ | ✔ | | ✔ | |

| 'HMAC' | | | ✔ | ✔ | ✔ | | |

| 'KMAC128'⁴ | | | ✔ | | ✔ | | |

| 'KMAC256'⁴ | | | ✔ | | ✔ | | |

| 'ML-DSA-44'⁴ | ✔ | ✔ | ✔ | | | ✔ | ✔ |

| 'ML-DSA-65'⁴ | ✔ | ✔ | ✔ | | | ✔ | ✔ |

| 'ML-DSA-87'⁴ | ✔ | ✔ | ✔ | | | ✔ | ✔ |

| 'ML-KEM-512'[^现代算法] | ✔ | ✔ | | | | ✔ | ✔ |

| 'ML-KEM-768'[^现代算法] | ✔ | ✔ | | | | ✔ | ✔ |

| 'ML-KEM-1024'⁴ | ✔ | ✔ | | | | ✔ | ✔ |

| 'RSA-OAEP' | ✔ | ✔ | ✔ | | | | |

| 'RSA-PSS' | ✔ | ✔ | ✔ | | | | |

| 'RSASSA-PKCS1-v1_5' | ✔ | ✔ | ✔ | | | | |