knowing salt that used when encryption AES 256

Question

I have a password like "abd123456", that I encrypt with AES-256 encryption. After Base-64 encoding, the result would be the 44 character string:

IXCgaa5igYxzKTRTP+PMT7Bt9iIWiF6EWLmnKqZtlXI=

How can I know the salt that the .NET Framework's RijndaelManaged AES encryption class used during encryption?

I know the plaintext that is being encrypted, and the encryption key. But how do I know the Salt used?

I'm voting to close this question as off-topic because it belongs on http://crypto.stackexchange.com/ — HTTP 410, Dec 30 '15 at 00:33
why this is new ideas that can help all to check his powerfull encryption what is this site ( crypto ) ?? — محمد عبدالغفار الفقى, Dec 30 '15 at 01:32
no i have the normal password and pass after encryption i think it in AES 256 IN base64 how know the key that use ??? — محمد عبدالغفار الفقى, Jan 17 '16 at 22:01

Ian Boyd · Answer 1 · 2015-12-30T20:01:57.797

0

You can read the salt from the .IV property of the AES encryption object.

From MSDN documentation:

The IV property is automatically set to a new random value whenever you create a new instance of one of the SymmetricAlgorithm classes.

Simply read the .IV after creating your encryptor. Then you can save the salt, or replace it with your own desired salt. Salt does not have to be secret, or even cryptographically random - it just has to be different each and every time.

edited Dec 30 '15 at 20:01

answered Dec 30 '15 at 00:48

Ian Boyd

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... The IV is not secret, so it can be sent along with the ciphertext. It's common to simply prepend it to the ciphertext, because its length is known in advance. – Artjom B. Dec 30 '15 at 08:50
no i have the normal password and pass after encryption i think it in AES 256 IN base64 how know the key that use ??? – محمد عبدالغفار الفقى Jan 17 '16 at 22:01

knowing salt that used when encryption AES 256

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