Update README

[linuxjm/LDP_man-pages.git] / original / man3 / memcmp.3

diff --git a/original/man3/memcmp.3 b/original/man3/memcmp.3
index 1955cca..9443da2 100644 (file)
--- a/original/man3/memcmp.3
+++ b/original/man3/memcmp.3
@@ -73,7 +73,12 @@ SVr4, 4.3BSD, C89, C99, POSIX.1-2001.
 Do not use
 .BR memcmp ()
 to compare security critical data, such as cryptographic secrets,
-because the required CPU time depends on the amount of equal bytes.
+because the required CPU time depends on the number of equal bytes.
+Instead, a function that performs comparisons in constant time is required.
+Some operating systems provide such a function (e.g., NetBSD's
+.BR consttime_memequal ()),
+but no such function is specified in POSIX.
+On Linux, it may be necessary to implement such a function oneself.
 .SH SEE ALSO
 .BR bcmp (3),
 .BR strcasecmp (3),
@@ -83,7 +88,7 @@ because the required CPU time depends on the amount of equal bytes.
 .BR strncmp (3),
 .BR wmemcmp (3)
 .SH COLOPHON
-This page is part of release 3.76 of the Linux
+This page is part of release 3.79 of the Linux
 .I man-pages
 project.
 A description of the project,