Why is AES encrypted cipher of the same string with the same key always different?

Question

I have a file called plain.txt. Inside the file I have:

Hello Hello Hello Hello

I am using this command to encrypt it:

openssl          


        

Answer 1

You get different outputs on each run because new salt is generated each time you run the command. In order to provide the same salt for each consecutive run use -S salt option, i.e.

openssl enc -aes-128-cbc -salt -S "Salt" -k "Hello" -in plain.txt -out encrypted.bin