CryptographicException: Bad Data. Any idea why this happens?

[simonmarkjones]

Hi my webserver is running .Net 1.1 and intermittently i get the
following error when I look at one of the websites. Does anyone out
there have any idea why this happens?

And how I can try and start solving the problem. Most of the time the
website works okay. Thanks in advance!

Server Error in '/Ed/ENROL' Application.
---------------------------------------------------------------------------­-----



Bad Data.
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.


Exception Details: System.Security.Cryptography.CryptographicException:

Bad Data.


Source Error:


An unhandled exception was generated during the execution of the
current web request. Information regarding the origin and location of
the exception can be identified using the exception stack trace below.


Stack Trace:


[CryptographicException: Bad Data.
]
System.Security.Cryptography.CryptoAPITransform._DecryptData(IntPtr
hKey, Byte[] rgb, Int32 ib, Int32 cb, Boolean fDone) +0


System.Security.Cryptography.CryptoAPITransform.TransformFinalBlock(Byte[]

inputBuffer, Int32 inputOffset, Int32 inputCount) +805
System.Security.Cryptography.CryptoStream.FlushFinalBlock() +40
System.Web.Configuration.MachineKey.EncryptOrDecryptData(Boolean
fEncrypt, Byte[] buf, Byte[] modifier, Int32 start, Int32 length) +139
System.Web.Security.FormsAuthentication.Decrypt(String
encryptedTicket) +114
FSSL.Enrol.WebUI.Global.Application_AuthenticateRequest(Object
sender, EventArgs e) +79


System.Web.SyncEventExecutionStep.System.Web.HttpApplication+IExecutionStep­.Execute()

+60
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&

completedSynchronously) +87


---------------------------------------------------------------------------­-----

Version Information: Microsoft .NET Framework Version:1.1.4322.2300;
ASP.NET Version:1.1.4322.2300

 

[MikeS]

I think I have seen this when the data to be decrypted was not the
correct length.