StoreKit verification error 21002: The data in the receipt-data property was malformed

Question

On a iPhone 4/iOS 4 device, sandbox App Store is reporting this error during verification:

21002: The data in the receipt-data property was malformed.

Answer 1

For your sandbox environment use: https://sandbox.itunes.apple.com/verifyReceipt

For actual verification use: https://buy.itunes.apple.com/verifyReceipt

You can check this at Apple's official page.