key-bindings for the most common server commands and new key-bindings
can be added easily.
-### para_fade ###
+### para_mixer ###
An alarm clock and volume-fader for OSS and ALSA.
------------
### For the impatient ###
+ git clone git://git.tuebingen.mpg.de/lopsub
+ cd lopsub && make && sudo make install
git clone git://git.tuebingen.mpg.de/osl
cd osl && make && sudo make install && sudo ldconfig
- sudo apt-get install autoconf libssl-dev help2man gengetopt m4 \
+ sudo apt-get install autoconf libssl-dev m4 \
libmad0-dev libid3tag0-dev libasound2-dev libvorbis-dev \
libfaad-dev libspeex-dev libFLAC-dev libsamplerate-dev realpath \
libasound2-dev libao-dev libreadline-dev libncurses-dev \
git clone git://git.tuebingen.mpg.de/osl
+- [lopsub](http://people.tuebingen.mpg.de/maan/lopsub/). The long
+option parser for subcommands generates the command line and config
+file parsers for all paraslash executables. Clone the source code
+repository with
+
+ git clone git://git.tuebingen.mpg.de/lopsub
+
- [gcc](ftp://ftp.gnu.org/pub/gnu/gcc) or
[clang](http://clang.llvm.org). All gcc versions >= 4.2 are currently
supported. Clang version 1.1 or newer should work as well.
during compilation require the _Bourne again shell_. It is most
likely already installed.
-- [gengetopt](ftp://ftp.gnu.org/pub/gnu/gengetopt/) is needed to
-generate the C code for the command line parsers of all paraslash
-executables.
-
-- [help2man](ftp://ftp.gnu.org/pub/gnu/help2man) is used to create
-the man pages.
-
- [m4](ftp://ftp.gnu.org/pub/gnu/m4/). Some source files are generated
from templates by the m4 macro processor.
you need libogg, libvorbis, libvorbisfile. The corresponding Debian
packages are called `libogg-dev` and `libvorbis-dev`.
-- [libfaad](http://www.audiocoding.com/). For aac files (m4a) you
-need libfaad (`libfaad-dev`).
+- [libfaad and mp4ff](http://www.audiocoding.com/). For aac files
+(m4a) you need libfaad and libmp4ff (package: `libfaad-dev`). Note
+that for some distributions, e.g. Ubuntu, mp4ff is not part of the
+libfaad package. Install the faad library from sources (available
+through the above link) to get the mp4ff library and header files.
- [speex](http://www.speex.org/). In order to stream or decode speex
files, libspeex (`libspeex-dev`) is required.
para_server uses a challenge-response mechanism to authenticate
requests from incoming connections, similar to ssh's public key
authentication method. Authenticated connections are encrypted using
-a stream cipher, either RC4 or AES in integer counter mode.
+the AES stream cipher in integer counter mode.
-In this chapter we briefly describe RSA, RC4 and AES, and sketch the
+In this chapter we briefly describe RSA and AES, and sketch the
[authentication handshake](#Client-server.authentication)
between para_client and para_server. User management is discussed
in the section on [the user_list file](#The.user_list.file).
server. Connecting para_audiod is a different matter and is described
in a [separate section](#Connecting.para_audiod).
-RSA, RC4, AES
--------------
+RSA and AES
+-----------
-RSA is an asymmetric block cipher which is used in many applications,
-including ssh and gpg. An RSA key consists in fact of two keys,
+A block cipher is a transformation which operates on fixed-length
+blocks. For symmetric block ciphers the transformation is determined
+by a single key for both encryption and decryption. For asymmetric
+block ciphers, on the other hand, the key consists of two parts,
called the public key and the private key. A message can be encrypted
-with either key and only the counterpart of that key can decrypt
-the message. While RSA can be used for both signing and encrypting
-a message, paraslash uses RSA only for the latter purpose. The
-RSA public key encryption and signatures algorithms are defined in
-detail in RFC 2437.
-
-RC4 is a stream cipher, i.e. the input is XORed with a pseudo-random
-key stream to produce the output. Decryption uses the same function
-calls as encryption. While RC4 supports variable key lengths,
-paraslash uses a fixed length of 256 bits, which is considered a
-strong encryption by today's standards. Since the same key must never
-be used twice, a different, randomly-generated key is used for every
-new connection.
+with either key and only the counterpart of that key can decrypt the
+message. Asymmetric block ciphers can be used for both signing and
+encrypting a message.
+
+RSA is an asymmetric block cipher which is used in many applications,
+including ssh and gpg. The RSA public key encryption and signatures
+algorithms are defined in detail in RFC 2437. Paraslash relies on
+RSA for authentication.
+
+Stream ciphers XOR the input with a pseudo-random key stream to produce
+the output. Decryption uses the same function calls as encryption.
+Any block cipher can be turned into a stream cipher by generating the
+pseudo-random key stream by encrypting successive values of a counter
+(counter mode).
AES, the advanced encryption standard, is a well-known symmetric block
-cipher, i.e. a transformation operating on fixed-length blocks which
-is determined by a single key for both encryption and decryption. Any
-block cipher can be turned into a stream cipher by generating
-a pseudo-random key stream by encrypting successive values of a
-counter. The AES_CTR128 stream cipher used in paraslash is obtained
-in this way from the AES block cipher with a 128 bit block size.
+cipher. Paraslash employs AES in counter mode as described above to
+encrypt communications. Since a stream cipher key must not be used
+twice, a random key is generated for every new connection.
Client-server authentication
----------------------------
the session key known to both peers.
paraslash relies on the quality of the pseudo-random bytes provided
-by the crypto library (openssl or libgcrypt), on the security of the
-implementation of the RSA, RC4 and AES crypto routines and on the
+by the crypto library (openssl or libgcrypt), on the security of
+the implementation of the RSA and AES crypto routines and on the
infeasibility to invert the SHA1 function.
Neither para_server or para_client create RSA keys on their
para_client help
-contains in the third column the permissions needed to execute the
-command.
+contains the permissions needed to execute the command.
It is possible to make para_server reread the user_list file by
executing the paraslash "hup" command or by sending SIGHUP to the
projects / paraslash.git / blobdiff