Home / ubuntu / Questions / 1214413
In Process
Ultracrepidarian
Asked: 2020-03-03 17:01:09 +0800 CST

Attempting to Decrypt an AES-256-CBC Encrypted File but Decryption Password isn't known

  • 772

I am trying to decrypt a password protected file that was encrypted using AES-256-CBC, but the password to decrypt the file has been forgotten.

In this simulation, I do know the password is a dictionary word, and I have a word list to try a dictionary attack against the password. I also know that no salt was used when encrypting the file. But I am unsure on how to find the right method to do this.

My mind keeps going to JTR, but I need to use OpenSSL commands. I would appreciate the help!

I am using OpenSSL 1.1.1 and Ubuntu 16.04 LTS.

encryption command-line password 16.04 openssl

1 Answers

  1. You can create a simple shell script to iterate through your dictionary file (search on StackOverflow if you don't know how).

    Then use this command to attempt decryption: (source)

    openssl enc -d -aes-256-cbc -k $password -in encrypted.data -out un_encrypted.data

    You will also need some method to decide whether the decrypted data is of the format you expect. The file command could be useful.

    • 0