Why can't I decrypt a string I've just encrypted?

If you are using one of .NET CryptoService providers (like DESCryptoServiceProvider or RijndaelManaged), there's a trap that you can easily fall in (I did).

To encrypt data (a string converted previously into a byte array), you create a CryptoStream that reads bytes from this array, transforms them, and then writes encrypted data to a stream.

Then you can use ToArray() method of the stream to obtain encrypted bytes.

And what do you do next?

You run something like:
  Encoding.Unicode.GetString(cipherBytes)

And you have a problem. The encrypted string is encoded in Unicode. That's fine as long as you want to write it into a file or store in a database, but sometimes you want to be able to enter it using the keyboard.

To solve this problem use:
  Convert.ToBase64String(cipherBytes)

This way the encrypted string will be encoded with ASCII characters only.

If you want to know more, read this article.

DTS packages & jobs

I created a simple DTS package, I executed and it worked just fine.

Then I scheduled it and tried to execute the job. The job failed. It consisted only of one step which executed the package, so I was pretty speechless.

I opened job's history. It looked pretty awful (many lines of text without newline characters), but I managed to find a few occurrences of 'Access denied' phrase.

Then I remembered that there was something like 'Script file directory' textbox in 'Copy SQL Server Objects Task' window. I also realized that the domain account that I use to run SQL Server Agent service has very limited permissions.

I changed the path in 'Script file directory' textbox to one that SQL Server Agent could access and this time the job executed.