Hello folks,
I have an issue, i hope you can help me with. I got a challenge from my son - he is a graduating IT student and i have very little knowledge compared with him. However he challenged me to decrypt a hidden message for an exchange he quits smoking.
What i have figure out is that the message is salted and encrypted with AES as "U2FsdGVkX18" stands for salted. He also gave me salt, encrypted message, MD5 hash of this message IV and key. What he did not gave me is password. Only a hint to it that it contains 5 letters from A to H and 4 numbers 0-9. I was reading online that there is a way to derive keys/IVs from a password and then compare derived key and IV with the one i have. This way i will know the exact password? I could try to derive every single password by hand but i assume it is a life worth effort. Is there any way that i could run a code in python or open SSL to do this by computer?
Thank you in advance for an assistance.
AES encrypted message issue
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paulej
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Re: AES encrypted message issue
The string "U2FsdGVkX18" is not encrypted data. That's just a base64 encoding of "Salted__".
That might be the first few bytes of the encrypted file. That's typical of OpenSSL to form a file like that.
There's no way to break AES encryption, but you can iterate over all of the possibilities. Knowing it's exactly 5 letters followed by 4 numbers, you can just try every combination. But, you'll need the complete file. AES is just a block cipher, so to create an encrypted file there are one is several modes and a key length. There are three possible key lengths, but we'd need to know how to derive the key from the password.
Did he just give you bits and pieces, and not a complete file?
That might be the first few bytes of the encrypted file. That's typical of OpenSSL to form a file like that.
There's no way to break AES encryption, but you can iterate over all of the possibilities. Knowing it's exactly 5 letters followed by 4 numbers, you can just try every combination. But, you'll need the complete file. AES is just a block cipher, so to create an encrypted file there are one is several modes and a key length. There are three possible key lengths, but we'd need to know how to derive the key from the password.
Did he just give you bits and pieces, and not a complete file?