AESCRYPT(1) BSD General Commands Manual AESCRYPT(1)NAMEaescrypt — encrypt data using Rijndael, the Advanced Encryption Standard
winner
SYNOPSISaescrypt-k keyfile [-s keysize]
DESCRIPTION
The aescrypt utility encrypts data using the Rijndael algorithm, the win‐
ner of the Advanced Encryption Standard (AES) competition. The encryp‐
tion is done in Cipher Block Feedback (CFB-128) mode, with the salt ran‐
domly generated from data read from the /dev/urandom device. The plain‐
text data is read from standard input and the encrypted data is written
to standard output.
The encryption key may be read from standard input or from a file,
depending on the argument passed to the -k command-line option. If “-”
is used as a filename, the aescrypt utility reads as many hexadecimal
digits as needed from standard input and then one additional byte to
allow for a newline separating the key from the actual data to be
encrypted. If the filename is not “-”, the aescrypt utility opens the
specified file and reads text lines from it until a line starting with
the characters kk= is reached. Those characters should be immediately
followed by as many hexadecimal digits as needed; the rest of the line,
as well as the rest of the file, is ignored.
The encryption key may be 128, 192, or 256 bits long. By default, the
aescrypt utility uses (and expects to read) a 128-bit key, unless a dif‐
ferent size is supplied by the -s keysize command-line option.
The aescrypt utility reads 16 bytes (128 bits) from the /dev/urandom
device to initialize the salt for the CFB-128 encryption. The salt is
prepended to the encrypted data in the output.
EXAMPLES
Generate a random 128-bit value and store it into a keyfile suitable for
the aescrypt utility:
perl -e 'open(F, "<", "/dev/random") or die("$!\n"); read(F, $s,
32); print "kk=".unpack("H*", $s)."\n"'
Encrypt the contents of the /etc/hosts file with the generated (128-bit
by default) key:
aescrypt-k key.txt < /etc/hosts > hosts.aes
Encrypt a string with a 192-bit key supplied directly:
(echo '012345678901234567890123456789012345678901234567'; echo
'This is a test.') | ./aescrypt -s 192 -k - > test.aes
SEE ALSOaesget(1)
The SourceForge project page: http://sourceforge.net/projects/aescrypt/
HISTORY
The aescrypt utility was written by Eric Lee Green, and was modified to
use Rijndael rather than Twofish by Randy Kaelber. It uses the freely
available Rijndael implementation by Antoon Bosselaers and Vincent
Rijmen. This manual page was written by Peter Pentchev in 2008.
AUTHORS
The aescrypt utility - Eric Lee Green ⟨eric@badtux.org⟩, Randy Kaelber
⟨randyk@sourceforge.net⟩.
The manual page - Peter Pentchev ⟨roam@ringlet.net⟩.
BSD June 8, 2008 BSD
