The main issue in your code was caused by a failure to specify an IV value. You must specify an IV value when doing CBC-mode encryption and use that same value when performing the CBC-mode decryption. Another problem is the mix and match of creating strings from byte arrays and base64-encoding. You also return null … Read more
The gen.generate(msg, false) means the signed data is not encapsulated in the signature. This is fine if you want to create a detached signature, but it does mean that when you go to verify the SignedData you have to use the CMSSignedData constructor that takes a copy of the data as well – in this … Read more
You can’t guarantee the security of the timings cryptographically, because the client’s browser can’t do secure computation. Any means for encrypting to/from the server could be bypassed by adjusting the actual timings. And timing on the server doesn’t work, either – if you don’t take account of latency in the round-trip-time, users with lower latency … Read more
This is the downside of symmetric-key challenge-response style authentication – you don’t put the secret on the wire, but you have to store the secret at both ends. (HMACs are symmetric key systems). Note though that it’s not a password – it’s a shared secret. There’s a fundamental difference here – a password is generally … Read more
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
The algorithm you are using, “AES”, is a shorthand for “AES/ECB/NoPadding”. What this means is that you are using the AES algorithm with 128-bit key size and block size, with the ECB mode of operation and no padding. In other words: you are only able to encrypt data in blocks of 128 bits or 16 … Read more