Calling HTTPS Web Service from iOS Application

I can call the HTTP web service but when 开发者_运维技巧the same service is HTTPS it throws error that it cannot be called. I am invoking it from iOS application. Do I need to pass some additional header fields related to HTTPS.

UPDATE (SOLUTION):

Seems like it just needed the HOST header parameter.

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if you are not passing any authorization parameters in any way to the service and it is just a url: "https://www.xxxxxx.com/dev/tools/search=?" the issue is from server side authentication certificate. they need to allow the request to be taken in from server's end by configuring server authentication certificate.