OpenSourceEncryptionSoftware

dm-crypt

Description

Dm-crypt is part of the Linux Kernel. Some distributions might not include it in their kernel configurations, however. It is a lot like TrueCrypt: it allows you to mount encrypted files or partitions and decrypt/encrypt them on-the-fly.

Manual setup

Your distro probably comes with a tool to simplify using dm-crypt. However, here is how you would manually mount a file-hosted dm-crypt volume. The hashalot tool is used to prompt you for and process your password. This is used both to create the device and access it:

losetup /dev/loop0 ~/encrypted
HASH=`hashalot -s InsertSaltHere sha256 | hexdump -e '32/1 "%02x"'`
echo 0 `blockdev --getsize /dev/loop0` crypt aes-cbc-essiv:sha256 \
$HASH 0 /dev/loop0 0 | dmsetup create dmDevice
mount /dev/mapper/dmDevice /mnt/encrypted

• Losetup makes the container file (~/encrypted in this case) act like a device.
• The hashalot command prompts you for a password and then hashes it, adding the specified salt. The salt should be random, but it mustn't change.
• The hexdump command puts the binary hashalot output into the format required for dm-crypt
• Dm-crypt is set up on the /dev/loop0 device created by losetup. It uses the password hash created previously. The aes-cbc-essiv:sha256 encryption method is secure, though probably not as secure as Truecrypt's XTS method, which does not appear to be available in official kernel releases as far as I can tell. The dm-crypt device is created as /dev/mapper/dmDevice in this example.
• The device is mounted. Before you do this for the first time, you need to run mke2fs. If you ever enter the wrong password, the device will appear to contain random data and attempting to mount it will fail.

eCryptfs

Description

eCryptfs is a POSIX-compliant enterprise-class stacked cryptographic filesystem for Linux.

Download

Latest source link on right side of page.

All downloads.

Examples

Examples can be found in Damien Oh's article How To Encrypt Files in Linux with eCryptfs.

FAQ

FAQ

HomePage

eCryptfs - Enterprise Cryptographic Filesystem

License

GPL 2+

OpenSSL

Description

The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, full-featured, and Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library.

Donation

Donation page.

Download

Source

Examples

Based on Grondilu's post, to encrypt the wallet, from a terminal in the bitcoin parent directory, type:

openssl enc -aes256 -in ./.bitcoin/wallet.dat -out wallet.aes256

From Paul Heinlein's openssl command line how to, to decode, add the '-d' option, set the '-in' option to the output file name, to type:

openssl enc -d -aes256 -in wallet.aes256 -out wallet.dat

FAQ

FAQ

HomePage

OpenSSL Project

License

Dual licensed under two BSD style open source licenses.

True Crypt

Description

Free open-source disk encryption software for Windows 7/Vista/XP, Mac OS X, and Linux. True Crypt creates a virtual encrypted disk within a file and mounts it as a real disk.

Documentation

Documentation page.

Donation

Donation page.

Download

Binaries

Source

FAQ

FAQ

HomePage

TrueCrypt

License

True Crypt Open Source License.