Decrypts data by using an asymmetric key.
Usage notes
- Keys outside Key Management Service (KMS) instances: To perform cryptographic operations, use Alibaba Cloud SDK to call operations.
- Keys in KMS instances: To perform cryptographic operations, use one of the following methods:
- Method 1 (recommended): Use KMS Instance SDK to call KMS Instance API operations. For more information, see KMS Instance SDK and KMS Instance API.
- Method 2: Use Alibaba Cloud SDK to call operations. The authentication method supports only Resource Access Management (RAM) roles whose trusted entities are Alibaba Cloud services. For more information, see Create a RAM role for a trusted Alibaba Cloud service.
Limits
You can call this operation up to 200 times per second per account. If the number of calls per second exceeds the limit, throttling is triggered. As a result, your business may be affected. We recommend that you take note of the limit when you call this operation.
Description
This operation supports only asymmetric keys for which Usage is set to ENCRYPT/DECRYPT. The following table lists supported encryption algorithms.
KeySpec |
Algorithm |
Description |
Maximum length in bytes |
RSA_2048 |
RSAES_OAEP_SHA_256 |
RSAES-OAEP using SHA-256 and MGF1 with SHA-256 |
256 |
RSA_2048 |
RSAES_OAEP_SHA_1 |
RSAES-OAEP using SHA1 and MGF1 with SHA1 |
256 |
RSA_3072 |
RSAES_OAEP_SHA_256 |
RSAES-OAEP using SHA-256 and MGF1 with SHA-256 |
384 |
RSA_3072 |
RSAES_OAEP_SHA_1 |
RSAES-OAEP using SHA1 and MGF1 with SHA1 |
384 |
EC_SM2 |
SM2PKE |
SM2 public key encryption algorithm based on elliptic curves |
6144 |
In this example, an asymmetric key whose ID is hzz630494463ejqjx**** andversion ID is 2ab1a983-7072-4bbc-a582-584b5bd8**** and the RSAES_OAEP_SHA_1 algorithm are used to decrypt the ciphertext BQKP+1zK6+ZEMxTP5qaVzcsgXtWplYBKm0NXdSnB5FzliFxE1bSiu4dnEIlca2JpeH7yz1/S6fed630H+hIH6DoM25fTLNcKj+mFB0Xnh9m2+HN59Mn4qyTfcUeadnfCXSWcGBouhXFwcdd2rJ3n337bzTf4jm659gZu3L0i6PLuxM9p7mqdwO0cKJPfGVfhnfMz+f4alMg79WB/NNyE2lyX7/qxvV49ObNrrJbKSFiz8Djocaf0IESNLMbfYI5bXjWkJlX92DQbKhibtQW8ZOJ//ZC6t0AWcUoKL6QDm/dg5koQalcleRinpB+QadFm894sLbVZ9+N4GVsv1W****==.
Debugging
Request parameters
|
Parameter |
Type |
Required |
Example |
Description |
| Action | String | Yes | AsymmetricDecrypt | The operation that you want to perform. Set the value to AsymmetricDecrypt. |
| CiphertextBlob | String | Yes | BQKP+1zK6+ZEMxTP5qaVzcsgXtWplYBKm0NXdSnB5FzliFxE1bSiu4dnEIlca2JpeH7yz1/S6fed630H+hIH6DoM25fTLNcKj+mFB0Xnh9m2+HN59Mn4qyTfcUeadnfCXSWcGBouhXFwcdd2rJ3n337bzTf4jm659gZu3L0i6PLuxM9p7mqdwO0cKJPfGVfhnfMz+f4alMg79WB/NNyE2lyX7/qxvV49ObNrrJbKSFiz8Djocaf0IESNLMbfYI5bXjWkJlX92DQbKhibtQW8ZOJ//ZC6t0AWcUoKL6QDm/dg5koQalcleRinpB+QadFm894sLbVZ9+N4GVsv1W****== | The Base64-encoded ciphertext that you want to decrypt. Note You can call the AsymmetricEncrypt operation to generate ciphertext. |
| KeyId | String | Yes | key-hzz630494463ejqjx**** | The ID, alias, or Alibaba Cloud Resource Name (ARN) of the key. For more information, see Manage a key alias. Note When you access a key within another Alibaba Cloud account, you must enter the ARN of the key. The ARN of the key is in the acs:kms:${region}:${account}:key/${keyid} format. |
| KeyVersionId | String | Yes | 2ab1a983-7072-4bbc-a582-584b5bd8**** | The version ID of the key. The ID must be globally unique. |
| Algorithm | String | Yes | RSAES_OAEP_SHA_1 | The decryption algorithm. |
| DryRun | String | No | false | Specifies whether to perform a dry run. Valid values:
A dry run is used for testing in API calls. You can perform a dry run to check whether you have the permissions to access the resources that you want to manage and whether the request parameters are correctly configured. If you set DryRun to true in the request, KMS always returns an error code that indicates the cause of the error. KMS may return the following error codes:
|
Response parameters
Parameter |
Type |
Example |
Description |
| KeyVersionId | String | 2ab1a983-7072-4bbc-a582-584b5bd8**** | The version ID of the key that is used to encrypt the plaintext. |
| KeyId | String | key-hzz630494463ejqjx**** | The ID of the key. If KeyId is set to the alias or ARN of the key, the ID of the key is returned. |
| RequestId | String | 475f1620-b9d3-4d35-b5c6-3fbdd941423d | The request ID. |
| Plaintext | String | SGVsbG8gd29ybGQ= | The Base64-encoded plaintext that is generated after decryption. |
Examples
Sample requests
http(s)://[Endpoint]/?Action=AsymmetricDecrypt
&CiphertextBlob=BQKP+1zK6+ZEMxTP5qaVzcsgXtWplYBKm0NXdSnB5FzliFxE1bSiu4dnEIlca2JpeH7yz1/S6fed630H+hIH6DoM25fTLNcKj+mFB0Xnh9m2+HN59Mn4qyTfcUeadnfCXSWcGBouhXFwcdd2rJ3n337bzTf4jm659gZu3L0i6PLuxM9p7mqdwO0cKJPfGVfhnfMz+f4alMg79WB/NNyE2lyX7/qxvV49ObNrrJbKSFiz8Djocaf0IESNLMbfYI5bXjWkJlX92DQbKhibtQW8ZOJ//ZC6t0AWcUoKL6QDm/dg5koQalcleRinpB+QadFm894sLbVZ9+N4GVsv1W****==
&KeyId=key-hzz630494463ejqjx****
&KeyVersionId=2ab1a983-7072-4bbc-a582-584b5bd8****
&Algorithm=RSAES_OAEP_SHA_1
&DryRun=false
&<Common request parameters>Sample success responses
XML format
HTTP/1.1 200 OK
Content-Type:application/xml
<AsymmetricDecryptResponse>
<KeyVersionId>2ab1a983-7072-4bbc-a582-584b5bd8****</KeyVersionId>
<KeyId>key-hzz630494463ejqjx****</KeyId>
<RequestId>475f1620-b9d3-4d35-b5c6-3fbdd941423d</RequestId>
<Plaintext>SGVsbG8gd29ybGQ=</Plaintext>
</AsymmetricDecryptResponse>JSON format
HTTP/1.1 200 OK
Content-Type:application/json
{
"KeyVersionId" : "2ab1a983-7072-4bbc-a582-584b5bd8****",
"KeyId" : "key-hzz630494463ejqjx****",
"RequestId" : "475f1620-b9d3-4d35-b5c6-3fbdd941423d",
"Plaintext" : "SGVsbG8gd29ybGQ="
}Error codes
|
HttpCode |
Error code |
Error message |
Description |
| 400 | Rejected.UnsupportedOperation | Unsupported operation. | The operation is not supported. |
| 404 | Forbidden.AliasNotFound | The specified Alias is not found. | The specified alias is not found. |
| 404 | Forbidden.KeyNotFound | The specified Key is not found. | The specified key does not exist. |
For a list of error codes, see Service error codes.