# sencrypt-0.2  2005.08.19
http://scdbackup.webframe.org         scdbackup@gmx.net        Thomas Schmitt
http://scdbackup.sourceforge.net

-----------------------------------------------------------------------------

This is a blowfish based encryption/decryption filter extracted from 
  http://stic.webframe.org/stic-0.8.tar.gz
and provided as add-on for scdbackup at
  http://scdbackup.webframe.org/sencrypt-0.2.tar.gz

-----------------------------------------------------------------------------

Installation :

Unpack the tarball in a directory where you may create a new directory
sencrypt-0.2 :

  cd ~/test
  tar xzf .../sencrypt-0.2.tar.gz

Enter the newly created subdirectory sencrypt-0.2/src/sencrypt_build 
and run make :

  cd sencrypt-0.2/src/sencrypt_build
  make

Run a test :
  ../../sencrypt -e -k "Test key phrase" <../misc/sencrypt.c | \
  ../../sencrypt -d -k "Test key phrase" | \
  diff - ../misc/sencrypt.c && echo OK
should print "OK".

Try the same with non-identical -k key phrases :
  ../../sencrypt -e -k "Test key phrase" <../misc/sencrypt.c | \
  ../../sencrypt -d -k "Other key phrase" | \
  diff - ../misc/sencrypt.c && echo OK
should print "Binary files - and ../misc/sencrypt.c differ".

Copy the resulting binary to a directory from the list in your $PATH variable :

  su
  password:
  cp ../../sencrypt /usr/local/bin   
  exit

-----------------------------------------------------------------------------

Finally, read the help text of the program which it shows you
if called with no arguments or with any unknown argument :

  sencrypt 0.2
  usage : sencrypt -e|-d
             [-k key_phrase | -f file_address |
              -t tty_address] [-g] [-s number]
  256 bit Blowfish encryption filter with key phrases
  of up to 1000 characters.
  -e  causes encryption of stdin to stdout
  -d  causes decryption of stdin to stdout
  -f  sets the encryption key by reading a file
  -g  pre-compress by gzip / post-uncompress by gunzip
  -k  sets the encryption key (and is a security risk)
  -p  picky: decrypt and complain about faulty final byte
  -s  sets the number of bytes to be passed unaltered
  -t  sets the tty file address for eventual prompting
  If neither -k nor -u is given, then the key phrase is
  prompted at /dev/tty resp. the address set by -t.
  -g implies -s 10 to avoid known-cleartext attacks.
  Encrypted data are 1 to 8 bytes larger than clear text.
  Decryption produces clear text of original length.