Gnupg gpg2 IDEA
I'm trying to use my old pgp keys with Gnupg via gpg2.
I've successfully imported the keys both public and secret from my old key ring.
I've just tried to decrypt a file but I have the following error.
me@ubuntu:~/Documents$ gpg2 -d test01 gpg: protection algorithm 1 (IDEA) is not supported
the other data for the keys come up.
Gnupg offers an explanation about patents (the IDEA patent isn't compatible with gnupg) and a remedy: both here,
I followed the instructions at the end of the link and imported the idea.c.gz files into ~/.gnupg and unzipped them (only one of them unzipped) and tried to ./configure.
This didn't work. I made a directory called cipher, moved the two files into it and tried the ./configure command again. The system couldn't find configure.
Can anyone help me, please?
1 Answer
The IDEA patent expired world-wide some time ago. The easiest solution would be to upgrade to GnuPG 1.4.13 (or newer) containing the algorithm by default. Saucy is the first Ubuntu release to include this version.
If you can't:
The GnuPG website asks you to read to file headers, which explain how to build it:
/* * [snip] * To build a GnuPG with IDEA support, copy this file into the cipher/ * directory of the gnupg distribution, and ./configure and make as * usual. IDEA will be built directly in to the GnuPG binary. This * is the recommended way to use this file. */This means, you have to build GnuPG completely by yourself instead of using the repository package. Download and unpack the sources, and you will find a cipher directory. Put the file into there, and then continue with building GnuPG like described in the manual.
Or alternatively:
/* * If you are not building IDEA directly into GnuPG, and need to build * the dynamically loadable IDEA module, compile with: gcc -Wall -O2 -shared -fPIC -o idea idea.c * [snip] */This means, you're not linking the IDEA algorithm into GnuPG, but build it as a dynamic module (in Windows, you'd compare it with some .dll file). What the file header's aren't revealing is how this library will be loaded. Put the compiled binary into some place (for example ~/.gnupg/idea) and add this line to your ~/.gnupg/gpg.conf file:
load-extension ~/.gnupg/ideaThis will only offer IDEA in gpg (not gpg2)!
