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Diffstat (limited to 'README')
| -rw-r--r-- | README | 45 |
1 files changed, 35 insertions, 10 deletions
@@ -1,16 +1,14 @@ random-seed is a random seed management program. In contrast with other random seed implementations, random-seed will credit the random seed to the kernel entropy count. It attempts to prevent inadvertent random seed sharing by -checking that certain system identifiers, such as the machine ID and filesystem +checking that certain system identifiers such as the machine ID and filesystem ID have not changed between a save and load. If these identifiers do not match, random-seed will still load the random seed, but will not credit the entropy. -It is my understanding that other operating systems are either not commonly -imaged (e.g. BSDs) or have official tools for system image preparation (e.g. -sysprep for Windows). Therefore, random-seed is Linux specific. However, it -should be reasonably easy to port by simply adjusting the paths and changing -getrandom to /dev/random. +random-seed is intended for distribution use. For a system that is +administratively guaranteed not to be cloned, consider the random-seed-basic +project instead. random-seed requires the following to compile: @@ -18,8 +16,35 @@ random-seed requires the following to compile: - GNU make (BSD make is not fine) - Bourne-like sh (autoconf compatible, i.e. probably all of them) -If compiling from git, autoconf is also required. random-seed does not use -automake, gettext, or libtool. +random-seed also supports linking with libudev or libmount and libblkid. It is +highly recommended to enable libudev if your target platform includes udevd +(eudev is supported), as it allows detection of the hard drive ID. Otherwise, +it is highly recommended to enable libmount and libblkid, as these allow +reliable detection of the file system UUID. It is assumed that most GNU/Linux +systems will include the util-linux package that contains these libraries, so +that should cover almost everybody. Even so, if neither of these are compiled +in, random-seed will fall back on the statfs(2) system call and use the f_fsid +field to identify the file system, if the file system type is btrfs, ext2/3/4, +JFS, NTFS, reiserfs, or UBIFS. If the file system type is none of these, and +none of the above libraries have been compiled in, random-seed will only use +the machine ID for cloning detection. However, if you do not have libudev, you +probably also do not use systemd or dbus, so you will probably not have a +machine ID. In this case, random-seed will never credit the entropy, so you may +as well use a "dd if=random-seed of=/dev/urandom" script. -random-seed requires Linux 3.11 or higher supporting the getrandom(2) system -call. +When compiling from git, autoconf, aclocal, and autoconf-archive are required. +aclocal is provided by the automake package on most operating systems. [1] + +random-seed is Linux-specific, as it is my understanding that other operating +systems are either not commonly imaged (e.g. BSDs) or have official tools for +system image preparation (e.g. sysprep for Windows). However, it should be +reasonably easy to port by simply adjusting the paths and changing getrandom to +/dev/random. + +random-seed supports a daemonize mode. This is recommended on systems without +a centralized timer synchronization mechanism similar to Android or systemd. +random-seed uses under 100 KB of RAM and negligible CPU when daemonized. + +[1] Automake has a "Future of aclocal" section in its manual. This section has +contained the text "aclocal is expected to disappear" since its inception in +2003, more than 15 years ago as of writing. |