To get information about a custom authorizer

The following describe-authorizer example displays details for the specified custom authorizer.

aws iot describe-authorizer \
    --authorizer-name CustomAuthorizer

Output:

{
    "authorizerDescription": {
        "authorizerName": "CustomAuthorizer",
        "authorizerArn": "arn:aws:iot:us-west-2:123456789012:authorizer/CustomAuthorizer",
        "authorizerFunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:CustomAuthorizerFunction",
        "tokenKeyName": "MyAuthToken",
        "tokenSigningPublicKeys": {
            "FIRST_KEY": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1uJOB4lQPgG/lM6ZfIwo\nZ+7ENxAio9q6QD4FFqjGZsvjtYwjoe1RKK0U8Eq9xb5O3kRSmyIwTzwzm/f4Gf0Y\nZUloJ+t3PUUwHrmbYTAgTrCUgRFygjfgVwGCPs5ZAX4Eyqt5cr+AIHIiUDbxSa7p\nzwOBKPeic0asNJpqT8PkBbRaKyleJh5oo81NDHHmVtbBm5A5YiJjqYXLaVAowKzZ\n+GqsNvAQ9Jy1wI2VrEa1OfL8flDB/BJLm7zjpfPOHDJQgID0XnZwAlNnZcOhCwIx\n50g2LW2Oy9R/dmqtDmJiVP97Z4GykxPvwlYHrUXY0iW1R3AR/Ac1NhCTGZMwVDB1\nlQIDAQAB\n-----END PUBLIC KEY-----"
        },
        "status": "ACTIVE",
        "creationDate": 1571245658.069,
        "lastModifiedDate": 1571245658.069
    }
}

For more information, see DescribeAuthorizer in the AWS IoT API Reference.