Author: emaste Date: Mon Oct 3 13:12:44 2016 New Revision: 306636 URL: https://svnweb.freebsd.org/changeset/base/306636
Log: libc arc4_stir: use only kern.arandom sysctl The sysctl cannot fail. If it does fail on some FreeBSD derivative or after some future change, just abort() so that the problem will be found and fixed. It's preferable to provide an arc4random() function that cannot fail and cannot return poor quality random data. While abort() is not normally suitable for a library, it makes sense here. Reviewed by: ed, jonathan, markm MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D8077 Modified: head/lib/libc/gen/arc4random.c Modified: head/lib/libc/gen/arc4random.c ============================================================================== --- head/lib/libc/gen/arc4random.c Mon Oct 3 12:58:08 2016 (r306635) +++ head/lib/libc/gen/arc4random.c Mon Oct 3 13:12:44 2016 (r306636) @@ -137,35 +137,17 @@ arc4_sysctl(u_char *buf, size_t size) static void arc4_stir(void) { - int done, fd, i; - struct { - struct timeval tv; - pid_t pid; - u_char rnd[KEYSIZE]; - } rdat; + u_char rdat[KEYSIZE]; + int i; if (!rs_initialized) { arc4_init(); rs_initialized = 1; } - done = 0; - if (arc4_sysctl((u_char *)&rdat, KEYSIZE) == KEYSIZE) - done = 1; - if (!done) { - fd = _open(RANDOMDEV, O_RDONLY | O_CLOEXEC, 0); - if (fd >= 0) { - if (_read(fd, &rdat, KEYSIZE) == KEYSIZE) - done = 1; - (void)_close(fd); - } - } - if (!done) { - (void)gettimeofday(&rdat.tv, NULL); - rdat.pid = getpid(); - /* We'll just take whatever was on the stack too... */ - } + if (arc4_sysctl(rdat, KEYSIZE) != KEYSIZE) + abort(); /* Random sysctl cannot fail. */ - arc4_addrandom((u_char *)&rdat, KEYSIZE); + arc4_addrandom(rdat, KEYSIZE); /* * Discard early keystream, as per recommendations in: _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
