Help Center/ Identity and Access Management_Identity and Access Management (New Edition)/ API Reference/ API/ STS/ Querying the Authentication Result/ Decoding the Authentication Failure Cause
Updated on 2026-07-22 GMT+08:00
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Decoding the Authentication Failure Cause

Function

This API is used to decode the authentication failure cause.

Authorization Information

Each account root user has all the permissions required to call all APIs, but IAM users must be assigned the following required identity policy-based permissions. For details about the required permissions, see Permissions Policies and Supported Actions.

Action

Access Level

Resource Type (*: required)

Condition Key

Alias

Dependencies

sts::decodeAuthorizationMessage

Write

-

-

-

-

URI

POST /v5/decode-authorization-message

Request Parameters

Table 1 Request header parameters

Parameter

Mandatory

Type

Description

X-Security-Token

No

String

Definition:

security_token field of a temporary security credential.

Constraints:

When an API is called using a temporary security credential, the HTTP header X-Security-Token must be provided.

Range:

N/A

Default Value:

N/A
Table 2 Request body parameters

Parameter

Mandatory

Type

Description

encoded_message

Yes

String

Definition:

Encrypted authentication failure cause.

Constraints:

The length ranges from 1 to 10,240.

Range:

N/A

Default Value:

N/A

Response Parameters

Status code: 200

Table 3 Response body parameters

Parameter

Type

Description

decoded_message

String

Definition:

Plaintext of the authentication failure cause.

Range:

N/A.

Status code: 400

Table 4 Response body parameters

Parameter

Type

Description

error_code

String

Definition :

Error code. For details, see Error Code.

Range:

The format is STS5.XXXX, for example, STS5.1001.

error_msg

String

Definition :

Error message. For details, see Error Message.

Range:

N/A.

Status code: 401

Table 5 Response body parameters

Parameter

Type

Description

error_code

String

Definition :

Error code. For details, see Error Code.

Range:

The format is STS5.XXXX, for example, STS5.1001.

error_msg

String

Definition :

Error message. For details, see Error Message.

Range:

N/A.

Status code: 403

Table 6 Response body parameters

Parameter

Type

Description

error_code

String

Definition :

Error code. For details, see Error Code.

Range:

The format is STS5.XXXX, for example, STS5.1001.

error_msg

String

Definition :

Error message. For details, see Error Message.

Range:

N/A.

Status code: 500

Table 7 Response body parameters

Parameter

Type

Description

error_code

String

Definition :

Error code. For details, see Error Code.

Range:

The format is STS5.XXXX, for example, STS5.1001.

error_msg

String

Definition :

Error message. For details, see Error Message.

Range:

N/A.

Example Requests

Decoding the authentication failure cause

POST https://{endpoint}/v5/decode-authorization-message

{
  "encoded_message" : "HY0L8G1lOe3rcfgxfKVP+AK+S33eYp/rHQ4I0kJed9...rwaYmLp+pt/ICBwk"
}

Example Responses

Status code: 200

Successful

{
  "decoded_message" : "{\"context\":{\"user_profile\":...\"failure\":\"implicit deny by identity-based policy\"}"
}

Status Codes

Status Code

Description

200

Successful

400

Bad request

401

Authentication failed.

403

Forbidden

500

Server error

Error Codes

See Error Codes.