Function

This API enables you to decrypt a DEK using a specified CMK.

Data encryption results are used for decryption.

By default, the performance threshold for decrypting DEKs is 1000 TPS per customer. To apply for higher performance, submit a service ticket.

URI

URI format
POST /v1.0/{project_id}/kms/decrypt-datakey
Parameter description
Table 1 Parameter description
Parameter

Mandatory

Type

Description

project_id

Yes

String

Project ID

**Table 1** Parameter description
Parameter	Mandatory	Type	Description
project_id	Yes	String	Project ID

Requests

**Table 2** Request parameters
Parameter	Mandatory	Type	Description
key_id	Yes	String	36-byte ID of a CMK that matches the regular expression ^[0-9a-z]{8}-[0-9a-z]{4}-[0-9a-z]{4}-[0-9a-z]{4}-[0-9a-z]{12}$ Example: 0d0466b0-e727-4d9c-b35d-f84bb474a37f
encryption_context	No	Object	Key-value pairs with a maximum length of 8192 characters. This parameter is used to record resource context information, excluding sensitive information, to ensure data integrity. If this parameter is specified during encryption, it is also required for decryption. Example: {"Key1":"Value1","Key2":"Value2"}
cipher_text	Yes	String	This parameter indicates the hexadecimal character string of the DEK ciphertext and the metadata. The value is the cipher_text value in the encryption result of a DEK.
datakey_cipher_length	Yes	String	Number of bytes of a key. The value is 64.
sequence	No	String	36-byte serial number of a request message Example: 919c82d4-8046-4722-9094-35c3c6524cff

Responses

**Table 3** Response parameters
Parameter	Mandatory	Type	Description
data_key	Yes	String	Hexadecimal character string of the plaintext of a DEK
datakey_length	Yes	String	Number of bytes in the length of the plaintext of a DEK
datakey_dgst	Yes	String	Hexadecimal character string corresponding to the SHA-256 hash value of the plaintext of a DEK

Examples

The following is an example about how to use a CMK (ID: 0d0466b0-e727-4d9c-b35d-f84bb474a37f) to decrypt a DEK (ciphertext: 020098005273E14E6E8E95F5463BECDC27E80AF820B9FC086CB47861899149F67CF07DAFF2810B7D27BDF19AB7632488E0926A48DB2FC85BEA905119411B46244C5E6B8036C60A0B0B4842FFE6994518E89C19B1C1D688D9043BCD6053EA7BA0652642CE59F2543C80669139F4F71ABB9BD9A24330643034363662302D653732372D346439632D623335642D66383462623437346133376600000000D34457984F9730D57F228C210FD22CA6017913964B21D4ECE45D81092BB9112E; length: 64 bits).

Example request

{
    "key_id": "0d0466b0-e727-4d9c-b35d-f84bb474a37f",
    "datakey_cipher_length": "64",
    "cipher_text": "020098005273E14E6E8E95F5463BECDC27E80AF820B9FC086CB47861899149F67CF07DAFF2810B7D27BDF19AB7632488E0926A48DB2FC85BEA905119411B46244C5E6B8036C60A0B0B4842FFE6994518E89C19B1C1D688D9043BCD6053EA7BA0652642CE59F2543C80669139F4F71ABB9BD9A24330643034363662302D653732372D346439632D623335642D66383462623437346133376600000000D34457984F9730D57F228C210FD22CA6017913964B21D4ECE45D81092BB9112E"
}

Example response

{
    "data_key": "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
    "datakey_length": "64",
    "datakey_dgst": "F5A5FD42D16A20302798EF6ED309979B43003D2320D9F0E8EA9831A92759FB4B"
}

{
    "error": {
        "error_code": "KMS.XXXX",
        "error_msg": "XXX"
    }
}

Status Codes

Table 4 lists the normal status code returned by the response.

**Table 4** Status codes
Status Code	Status	Description
200	OK	Request processed successfully.

Exception status code. For details, see Status Codes.

Decrypting a DEK

Function

URI

Requests

Responses

Examples

Status Codes