mcookie - generate magic cookies for xauth
generates a 128-bit random hexadecimal number for use with the X
authority system. Typical usage:
xauth add :0 . `mcookie`
The "random" number generated is actually the output of the MD5
message digest fed with various pieces of random information: the current
time, the process id, the parent process id, and optionally the contents of an
input file. and several bytes of information from the first of the following
devices which is present: /dev/random
, files in
- -f, --file=FILE
- Use file as a macig cookie seed. When file is defined as `-' character
input is read from stdin.
- -v, --verbose
- Explain what is being done.
- -V, --version
- Output version information and exit.
- -h, --help
- Display this help and exit.
The entropy in the generated 128-bit is probably quite small (and, therefore,
vulnerable to attack) unless a non-pseudorandom number generator is used
It is assumed that none of the devices opened will block.
The mcookie command is part of the util-linux package and is available from