different between RSACryptoServiceProvider and RSAPKCS1Signatureformatter

Question

i am trying to get the difference between class RSAPKCS1Signatureformatter and RSACryptoServiceProvider as when i sign data using RSAPKCS1Signatureformatter it returns different signature value than signing using RSACryptoServiceProvider .

Answer 1

RSAPKCS1SignatureFormatter just calls RSACryptoServiceProvider.SignHash.

Since you don't have a code sample it's not easy to say what the problem is. Psychic debugging says that you're calling SignData when using the RSA object directly, which results in it getting hashed again, and that what you really want is SignHash (for pre-digested values).