SPEKE API v1 - 覆盖密钥标识符

每轮换一次密钥，加密程序就会创建一个新的密钥标识符 (KID)。它将 KID 传递到其请求中的 DRM 密钥提供程序。通常，使用相同 KID 的密钥提供程序会响应，但它可以在响应中提供其他 KID 值。

以下是 KID 为 11111111-1111-1111-1111-111111111111 的示例请求：

    <cpix:CPIX id="abc123" xmlns:cpix="urn:dashif:org:cpix" xmlns:pskc="urn:ietf:params:xml:ns:keyprov:pskc" xmlns:speke="urn:aws:amazon:com:speke">
      <cpix:ContentKeyList>
       <cpix:ContentKey kid="11111111-1111-1111-1111-111111111111"></cpix:ContentKey>
      </cpix:ContentKeyList>
      <cpix:DRMSystemList>
       <!-- Common encryption (Widevine)-->
       <cpix:DRMSystem kid="11111111-1111-1111-1111-111111111111" systemId="edef8ba9-79d6-4ace-a3c8-27dcd51d21ed">
        <cpix:PSSH />
       </cpix:DRMSystem>
      </cpix:DRMSystemList>
      <cpix:ContentKeyPeriodList>
       <cpix:ContentKeyPeriod id="keyPeriod_0909829f-40ff-4625-90fa-75da3e53278f" index="1" />
      </cpix:ContentKeyPeriodList>
      <cpix:ContentKeyUsageRuleList>
       <cpix:ContentKeyUsageRule kid="11111111-1111-1111-1111-111111111111">
        <cpix:KeyPeriodFilter periodId="keyPeriod_0909829f-40ff-4625-90fa-75da3e53278f" />
       </cpix:ContentKeyUsageRule>
      </cpix:ContentKeyUsageRuleList>
     </cpix:CPIX>

以下响应将 KID 覆盖为 22222222-2222-2222-2222-222222222222：

     <cpix:CPIX xmlns:cpix="urn:dashif:org:cpix" xmlns:pskc="urn:ietf:params:xml:ns:keyprov:pskc" xmlns:speke="urn:aws:amazon:com:speke" id="abc123">
      <cpix:ContentKeyList>
       <cpix:ContentKey explicitIV="ASgwx9pQ2/2lnDzJsUxWcQ==" kid="22222222-2222-2222-2222-222222222222">
        <cpix:Data>
         <pskc:Secret>
          <pskc:PlainValue>p3dWaHARtL97MpT7TE916w==</pskc:PlainValue>
         </pskc:Secret>
        </cpix:Data>
       </cpix:ContentKey>
      </cpix:ContentKeyList>
      <cpix:DRMSystemList>
       <cpix:DRMSystem kid="22222222-2222-2222-2222-222222222222" systemId="edef8ba9-79d6-4ace-a3c8-27dcd51d21ed">
        <cpix:PSSH>AAAAanBzc2gAAAAA7e+LqXnWSs6jyCfc1R0h7QAAAEoIARIQeSIcblaNbb7Dji6sAtKZzRoNd2lkZXZpbmVfdGVzdCIfa2V5LWlkOmVTSWNibGFOYmI3RGppNnNBdEtaelE9PSoCU0QyAA==</cpix:PSSH>
       </cpix:DRMSystem>
      </cpix:DRMSystemList>
      <cpix:ContentKeyPeriodList>
       <cpix:ContentKeyPeriod id="keyPeriod_0909829f-40ff-4625-90fa-75da3e53278f" index="1" />
      </cpix:ContentKeyPeriodList>
      <cpix:ContentKeyUsageRuleList>
       <cpix:ContentKeyUsageRule kid="22222222-2222-2222-2222-222222222222">
        <cpix:KeyPeriodFilter periodId="keyPeriod_0909829f-40ff-4625-90fa-75da3e53278f" />
       </cpix:ContentKeyUsageRule>
      </cpix:ContentKeyUsageRuleList>
     </cpix:CPIX>