git: 3bca93e04275 - main - rc.d/random: add support for zero harvest_mask

[Eugene Grosbein]

The branch main has been updated by eugen:

URL: https://cgit.FreeBSD.org/src/commit/?id=3bca93e04275045c3d868d09a57f9201999908f0

commit 3bca93e04275045c3d868d09a57f9201999908f0
Author:     Eugene Grosbein <eugen at FreeBSD.org>
AuthorDate: 2021-05-26 11:30:24 +0000
Commit:     Eugene Grosbein <eugen at FreeBSD.org>
CommitDate: 2021-05-26 11:30:24 +0000

    rc.d/random: add support for zero harvest_mask
    
    Replace the check for zero harvest_mask with new check for empty string.
    This allows one to specify harvest_mask="0" that disables harversting
    entropy from all but "pure" sources. Exact bit values for "pure" sources
    differ for stable/12 and later branches, so it is handy to use zero.
    The check for zero pre-dates introduction of "pure" non-maskable sources
    Use empty string to disable altering sysctl kern.random.harvest.mask.
    
    Note that notion of "pure" random sources is not documented in user level
    manual pages yet. Still, it helps to extend battery life for hardware
    with embedded "Intel Secure Key RNG" by disabling all other sources.
    
    Note that no defaults changed and default behaviour is not affected.
    
    Reported by:    Dmitry Luhtionov
---
 libexec/rc/rc.d/random | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libexec/rc/rc.d/random b/libexec/rc/rc.d/random
index d275284e13d6..fda3c8a71fae 100755
--- a/libexec/rc/rc.d/random
+++ b/libexec/rc/rc.d/random
@@ -47,7 +47,7 @@ feed_dev_random()
 random_start()
 {
 
-	if [ ${harvest_mask} -gt 0 ]; then
+	if [ -n "${harvest_mask}" ]; then
 		echo -n 'Setting up harvesting: '
 		${SYSCTL} kern.random.harvest.mask=${harvest_mask} > /dev/null
 		${SYSCTL_N} kern.random.harvest.mask_symbolic