GPG-Based Password Wallet

Keep your passwords safe in an encrypted file.
Edit Mode

In edit mode, wallet needs to decrypt the wallet file, open the decrypted file in a text editor, and then encrypt the edited file back to the original location. Line 74 uses mktemp to create a temporary directory, into which the wallet file will be decrypted. Line 75 sets $CLEARTEXT_WALLET_FILENAME to be the name of a file inside the temporary directory.

Line 79 runs trap, a bash built-in. The first argument to trap is a command, and this is followed by a list of signals (for example, if someone runs kill on wallet). If wallet receives any of these signals after line 79, wallet will run the trapped command (deleting the decrypted wallet file) prior to exiting. This is an attempt to ensure that the decrypted file isn't left sitting around if wallet terminates unexpectedly.

Line 83 is like what we saw in read-only mode, with the addition of the -o option to gpg. This instructs gpg to write the decrypted file to $CLEARTEXT_WALLET_FILENAME.

If gpg's exit code was 0, wallet renames the encrypted wallet file with a .bak extension (thus preserving a copy, in case something goes wrong) and opens the decrypted file in the text editor $VISUAL. After the editor exits, wallet tells gpg to encrypt the edited plain-text file at $CLEARTEXT_WALLET_FILENAME and to write the encrypted wallet file back to $WALLET_FILENAME. A nonzero exit status from this gpg call means that something went wrong in re-encrypting the wallet file, so wallet makes a copy of the plain-text file in your home directory and prints an error message.

Conclusion

wallet is a bash script for managing a password wallet. It's written to be usable over a text-only interface. Hopefully, this description of the code has helped you add an item or two to your bag of scripting tricks.

Carl Welch is a Web developer and Linux system administrator. He enjoys science fiction, is ambivalent to dentists and dislikes standard light switches. He maintains the lamest blog on planet Earth at mbrisby.blogspot.com.

______________________

Comments

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Just use vi directly

Anonymous's picture

Besides the issue with echo $PASSWORD already mentioned, this also puts a cleartext version of your secrets on disk, in tmp files, etc. Although there is an attempt to clean it all up, it's still rather messy and overly complex.
If you use vi, you can edit the gpg files directly with no cleartext ever touching the disk. And it's much simpler.

http://www.antagonism.org/privacy/gpg-vi.shtml

... and even worse: echo

Anonymous's picture

... and even worse:

echo $PASSWORD | gpg --decrypt --passphrase-fd 0

$PASSWORD will be visible to every local user, in cleartext on process list (ps command)

well...

Milo's picture

well, it's nice idea to use shred instead of rm. with rm -f you are deleting link to the inode, but inode itself is left untouched. on BSD rm -P should be sufficient.

White Paper
Linux Management with Red Hat Satellite: Measuring Business Impact and ROI

Linux has become a key foundation for supporting today's rapidly growing IT environments. Linux is being used to deploy business applications and databases, trading on its reputation as a low-cost operating environment. For many IT organizations, Linux is a mainstay for deploying Web servers and has evolved from handling basic file, print, and utility workloads to running mission-critical applications and databases, physically, virtually, and in the cloud. As Linux grows in importance in terms of value to the business, managing Linux environments to high standards of service quality — availability, security, and performance — becomes an essential requirement for business success.

Learn More

Sponsored by Red Hat

White Paper
Private PaaS for the Agile Enterprise

If you already use virtualized infrastructure, you are well on your way to leveraging the power of the cloud. Virtualization offers the promise of limitless resources, but how do you manage that scalability when your DevOps team doesn’t scale? In today’s hypercompetitive markets, fast results can make a difference between leading the pack vs. obsolescence. Organizations need more benefits from cloud computing than just raw resources. They need agility, flexibility, convenience, ROI, and control.

Stackato private Platform-as-a-Service technology from ActiveState extends your private cloud infrastructure by creating a private PaaS to provide on-demand availability, flexibility, control, and ultimately, faster time-to-market for your enterprise.

Learn More

Sponsored by ActiveState