Manpage of ppddcsum
Section: User Commands (1)
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ppddcsum - generates or checks a ppdd checksum
This program allows you to use checksums to protect the data on a ppdd
device from tampering. It can generate checksums on existing data and can
check an existing checksum.
The program works by reading all the data and generating an md5 hash and
then comparing this with an already existing md5 hash in the first 1024
bytes of the file (where it is protected by the key derived from the pass
phrase). The user can choose to check both the cipher and plain text hashes.
Normally the ciphertext hash is adequate and is much quicker.
The program normally operates on the file (or device) while it is not in
use by ppdd (i.e. before a ppddsetup -s or after a ppddsetup -d). However
in the case of root filesystem encryption it has to operate on the ppdd
device even while the filesystem is mounted. This special feature is
invoked by a -r switch and it should not be used for any other purpose.
If any invalid combination of switches and arguments is used the program
displays a primitive help message. The number of arguments depends on the
ppddcsum -g file_or_device
ppddcsum -gp file_or_device
ppddcsum -p file_or_device
Generating root filesystem checksum
ppddcsum -gr ppdd_device
Checking root filesystem checksum
ppddcsum -r ppdd_device
-g means generate
-p means plaintext checksum
-r means root filesystem
The program returns 0 if everything worked as expected.
The program returns 1 if anything has gone wrong.
All ppdd utilities display fairly meaningful errors (mostly on stderr).
In all cases the errors have a unique error number to help locate the
problem in the source code. If an error message is not clear then best
source of explanation at this stage is the source itself.
The program does not use any environment variables.
Files (and devices) are specified as arguments.
(c) 1999 Allan Latham - version 0.9
- Generating checksums
- Checking checksums
- Generating root filesystem checksum
- Checking root filesystem checksum
- RETURN VALUE
- SEE ALSO
This document was created by
using the manual pages.
Time: 16:35:26 GMT, September 14, 1999