There is a requirement to encrypt a string which I receive as a value of a named query parameter and pass it to another system (along with many other fields). This encryption is to be done by a public key provided to us so that receiving system will decrypt the string with their private key. What I have is a public key and not a certificate (which could have been imported into the trust store).
Is there a way I can get the public key to be imported into the trust store? Or is there a way I can fulfil the requirements on API Gateway without having to go back to them with alternatives.