grub2-signing-extension/sbin/grub2-unsign

#!/bin/bash
# grub2-unsign
# Unsigns every file in /boot. Depends on grub2-verify
# Author: Bandie Kojote
# Licence: GNU-GPLv3

# Check if something is wrong
if ! grub2-verify; then
    printf '%s\n' "grub2-verify has detected a one or more bad signatures." "Please check for malicious software before you're unsigning everything!" >&2
    exit 1
fi

# Then remove the signatures.
find /boot -name '*.sig' -exec rm -- '{}' +

echo "GRUB2 unsigned. WARNING: If you want to deactivate GRUB2's signature feature, change the check_signatures variable in the headers file!"
exit 0
First commit and release. 2015-03-16 19:38:36 +00:00			`#!/bin/bash`
			`# grub2-unsign`
			`# Unsigns every file in /boot. Depends on grub2-verify`
			`# Author: Bandie Kojote`
			`# Licence: GNU-GPLv3`

Comments and words. 2015-03-17 06:23:23 +00:00			`# Check if something is wrong`
Follow best practices for bash - Use native bash math where doing so improves readability. - Avoid illegal exit status codes (666 in impossible scenario). - Avoid useless use of cat (`cat foo \| bar` vs the more efficient `bar <foo`). - Avoid needless echo pipelines (`echo foo \| bar` vs `bar <<<"$foo"`). - Never use a for loop to iterate over output from `find`; `for` loops depend on string-splitting, which is only available with globbing behavior. See http://mywiki.wooledge.org/DontReadLinesWithFor - Use `read -s` to silence feedback rather than playing around with `stty`. - Use `tput` to retrieve color codes correct for the current terminal rather than assuming a terminal compatible with ANSI color codes. - Use a expression compatible with BSD `tr` in "passphrase-shredding" code. (BTW, I very much doubt that this code actually does any good; it's not a reasonable expectation that a new string assigned to a variable will actually be placed at the same location in memory). - Implementations of `echo` which do anything other than print `-e` on output when `echo -e` is run are nonconformant with the POSIX spec for echo. Similarly, `echo -n` behavior is not defined by the standard. Avoid relying on either of these. (See http://pubs.opengroup.org/onlinepubs/009604599/utilities/echo.html, particularly the APPLICATION USAGE section). - Always quote expansions to prevent string-splitting and glob-expansion (`"$i"`, not `$i`). - Avoid `some_command; if [ $? -eq 0 ]; then` when `if some_command; then` can be used instead. 2015-12-30 21:32:46 +00:00			`if ! grub2-verify; then`
			`printf '%s\n' "grub2-verify has detected a one or more bad signatures." "Please check for malicious software before you're unsigning everything!" >&2`
First commit and release. 2015-03-16 19:38:36 +00:00			`exit 1`
			`fi`
Comments and words. 2015-03-17 06:23:23 +00:00
			`# Then remove the signatures.`
Make rm more safe. 2015-12-29 20:26:53 +00:00			`find /boot -name '*.sig' -exec rm -- '{}' +`

Comments and words. 2015-03-17 06:23:23 +00:00			`echo "GRUB2 unsigned. WARNING: If you want to deactivate GRUB2's signature feature, change the check_signatures variable in the headers file!"`
Additional exit codes added + better shredding 2015-03-17 06:54:03 +00:00			`exit 0`