I had exactly this issue a few days ago. Turns out that there's a bug in setting up the GCM cipher, so the enc part is not working correctly for GCM. More than that, someone else will have to elaborate if you are interested.
--Jeremy On Tue, May 13, 2014 at 12:06 PM, Tom stone <stone...@gmail.com> wrote: > Using openssl-1.0.1g command line for simple file encryption/decryption, > when I issue the commands > > openssl enc -aes-256-cbc -k secret -in file.txt -out file.ssl > openssl enc -d -aes-256-cbc -k secret -in file.ssl > > The contents of file.txt go to stdout as expected. However, when I issue > the commands > > openssl enc -aes-256-gcm -k secret -in file.txt -out file.ssl > openssl enc -d -aes-256-gcm -k secret -in file.ssl > > The contents of file.txt go to stdout but the string "bad decrypt" goes to > stderr. > > Am I missing something or is there a bug in the openssl gcm implementation? > > I have tried substituting "-pass pass:secret" for "-k secret" and get the > same results. > > If I had to venture a guess, I would expect that the decrypt option > verifies that the input represents a full block of data and throws the > error when the gcm encrypted file does not end on a block boundary. > > >
