rijndaelmanaged – Tarik Billa

Why are RijndaelManaged and AesCryptoServiceProvider returning different results?

December 3, 2023 by Tarik

Response from Microsoft: RijndaelManaged class and AesCryptoServiceProvider class are two different implementations. RijndaelManaged class is a kind of implementation of Rijndael algorithm in .net framework, which was not validated under NIST (National Institute of Standards and Technology) Cryptographic Module Validation Program (CMVP). However, AesCryptoServiceProvider class calls the Windows Crypto API, which uses RSAENH.DLL, and has … Read more

Specified initialization vector (IV) does not match the block size for this algorithm

August 5, 2023 by Tarik

The problem is your initialization vector size needs to be 16 bytes. Your initial vector size is 14 bytes. You will need to increase the size of your initial vector by 2 bytes and your code will work. Example: string initVector = “HR$2pIjHR$2pIj12”; You will then get the output with your current code and the … Read more

Passphrase, Salt and IV, do I need all of these?

August 1, 2023 by Tarik

Yes, you need all of these things. Salt (and an “iteration count”) is used to derive a key from the password. Refer to PKCS #5 for more information. The salt and iteration count used for key derivation do not have to be secret. The salt should be unpredictable, however, and is best chosen randomly. CBC … Read more

Specified key is not a valid size for this algorithm

March 13, 2023 by Tarik

The string “ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz012345678912” when base64-decoded yields 48 bytes (384 bits). RijndaelManaged supports 128, 192 and 256 bit keys. A valid 128-bit key is new byte[]{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F } or if you need to get it from base64 : Convert.FromBase64String(“AAECAwQFBgcICQoLDA0ODw==”). The default … Read more

Using AES encryption in C#

December 23, 2022 by Tarik

If you just want to use the built-in crypto provider RijndaelManaged, check out the following help article (it also has a simple code sample): http://msdn.microsoft.com/en-us/library/system.security.cryptography.rijndaelmanaged.aspx And just in case you need the sample in a hurry, here it is in all its plagiarized glory: using System; using System.IO; using System.Security.Cryptography; namespace RijndaelManaged_Example { class RijndaelExample … Read more