[openssl-users] AES-GCM failing from Command Line Interface

[Dr. Stephen Henson]

On Mon, Feb 09, 2015, Sec_Aficionado wrote:

> Hello,
> 
> I am trying to encrypt a short message using AES-256-GCM as mentioned in the subject.
> 
> My command is:
> openssl enc -aes-256-gcm -p -in payload.txt -out enc.txt
> 
> I get prompted for password as expected.
> 
> The encryption goes well, and then I proceed to decrypt using:
> openssl enc -d -aes-256-gcm -p -in enc.txt -out dec.txt
> 
> The program executes but I get a "bad decrypt" message. However, when I open dec.txt, it is the same as the original file payload.txt
> 
> My guess is that the problem is in the padding, but I have not been able to eliminate the error message, even setting the -nopad option and padding manually.
> 
> Can someone please explain to me why this might be happening?
> 
> I am running openSSL 1.0.1f (6 Jan 14) on an Ubuntu 14.04 LTS VM with current patches.
> 

AES GCM is not supported by the 'enc' utility. More recent versions of OpenSSL
throw out and error message if you try to use it from the command line.

Steve.
--
Dr Stephen N. Henson. OpenSSL project core developer.
Commercial tech support now available see: http://www.openssl.org