Date: Fri, 26 Apr 2013 01:56:58 +0000 (UTC) From: "Andrey A. Chernov" <ache@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org Subject: svn commit: r249915 - in stable/9/sys: dev/random libkern sys Message-ID: <201304260156.r3Q1uwKv035510@svn.freebsd.org>
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Author: ache Date: Fri Apr 26 01:56:58 2013 New Revision: 249915 URL: http://svnweb.freebsd.org/changeset/base/249915 Log: MFC r249631 Attempt to mitigate poor initialization of arc4 by one-shot reinitialization from yarrow right after good entropy is harvested. Approved by: secteam (delphij) Modified: stable/9/sys/dev/random/randomdev_soft.c stable/9/sys/libkern/arc4random.c stable/9/sys/sys/libkern.h Directory Properties: stable/9/sys/ (props changed) stable/9/sys/dev/ (props changed) stable/9/sys/sys/ (props changed) Modified: stable/9/sys/dev/random/randomdev_soft.c ============================================================================== --- stable/9/sys/dev/random/randomdev_soft.c Fri Apr 26 00:53:34 2013 (r249914) +++ stable/9/sys/dev/random/randomdev_soft.c Fri Apr 26 01:56:58 2013 (r249915) @@ -366,6 +366,8 @@ random_yarrow_unblock(void) selwakeuppri(&random_systat.rsel, PUSER); wakeup(&random_systat); } + (void)atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_NONE, + ARC4_ENTR_HAVE); } static int Modified: stable/9/sys/libkern/arc4random.c ============================================================================== --- stable/9/sys/libkern/arc4random.c Fri Apr 26 00:53:34 2013 (r249914) +++ stable/9/sys/libkern/arc4random.c Fri Apr 26 01:56:58 2013 (r249915) @@ -24,6 +24,8 @@ __FBSDID("$FreeBSD$"); #define ARC4_RESEED_SECONDS 300 #define ARC4_KEYBYTES (256 / 8) +int arc4rand_iniseed_state = ARC4_ENTR_NONE; + static u_int8_t arc4_i, arc4_j; static int arc4_numruns = 0; static u_int8_t arc4_sbox[256]; @@ -130,7 +132,8 @@ arc4rand(void *ptr, u_int len, int resee struct timeval tv; getmicrouptime(&tv); - if (reseed || + if (atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_HAVE, + ARC4_ENTR_SEED) || reseed || (arc4_numruns > ARC4_RESEED_BYTES) || (tv.tv_sec > arc4_t_reseed)) arc4_randomstir(); Modified: stable/9/sys/sys/libkern.h ============================================================================== --- stable/9/sys/sys/libkern.h Fri Apr 26 00:53:34 2013 (r249914) +++ stable/9/sys/sys/libkern.h Fri Apr 26 01:56:58 2013 (r249915) @@ -70,6 +70,11 @@ static __inline int abs(int a) { return static __inline long labs(long a) { return (a < 0 ? -a : a); } static __inline quad_t qabs(quad_t a) { return (a < 0 ? -a : a); } +#define ARC4_ENTR_NONE 0 /* Don't have entropy yet. */ +#define ARC4_ENTR_HAVE 1 /* Have entropy. */ +#define ARC4_ENTR_SEED 2 /* Reseeding. */ +extern int arc4rand_iniseed_state; + /* Prototypes for non-quad routines. */ struct malloc_type; uint32_t arc4random(void);
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