NAME
imagesign - digitally sign an image
SYNOPSIS
imagesign [-v] [-u USER] [FILE]...
DESCRIPTION
imagesign is a utility for digitally signing images in-place, such that the images may continue to be viewed with a normal viewer.
If you or your organisation regularly produce images and you need to be able to tell later on whether an image has been modified from the original, or you need to be able to pass the images on to other people and they need to be able to check whether it really is you who sent them the image, then this utility may be useful to you.
It works by signing the image itself (not including any comment blocks) using gpg(1), and then embeds that signature in the image within a comment block. This comment block does not affect the image in any way.
Once the image has had a signature embedded in it, you can send it, store it, or whatever, treating it as you normally would. However, as soon as the image is modified in any way (even if it is just loaded and saved again), the signature will no longer be valid and imagesign --verify will tell you that the image is not the original that you signed.
OPTIONS
Options are read in order, from left to right, so you can sign some images and verify some others in the same command line if you particularly want to.
- -v, --verify
- Verify the signatures of the given images. An exit code of 1 (failure) means that one or more of the images failed the signature check.
- -u USER, --local-user USER
- When signing, sign as USER instead of the default user. This option is basically passed directly on to gpg(1) as-is, and applies to all files specified on the command line from this option onwards.
- -h, --help
- Print a usage message on standard output and exit successfully.
- -V, --version
- Print version information on standard output and exit successfully.
AUTHOR
Andrew Wood
http://www.ivarch.com/
BUGS
If you find any bugs, please contact the author, either by email or by using the contact form on the web site.
SEE ALSO
gpg(1), rdjpgcom(1), wrjpgcom(1)
LICENSE
This is free software, distributed under the ARTISTIC license.
Index
- NAME
- SYNOPSIS
- DESCRIPTION
- OPTIONS
- AUTHOR
- BUGS
- SEE ALSO
- LICENSE
This document was created by man2html, using the manual pages.
Time: 17:07:54 GMT, November 09, 2002