To ensure that data is encrypted both in-transit and at-rest, and to validate incoming requests to the Payment Processing API, the following approach is recommended:

TLS Inbound Policy: Apply a Transport Layer Security (TLS) - Inbound policy in API Manager. This policy ensures that the data is encrypted during transmission and can be decrypted by the API Manager before it reaches the Mule application.

Decryption: With the TLS policy applied, the message payload is decrypted when it is received by the API Manager.

JSON Validation: After decryption, the Mule application can use the JSON Validation module to validate the structure and content of the JSON data. This ensures that the payload conforms to the specified format and contains valid data.

This approach ensures that data is securely transmitted and properly validated upon receipt.

Transport Layer Security (TLS) Policies

JSON Validation Module