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author | Mihai Moldovan <ionic@ionic.de> | 2017-03-07 22:34:09 +0100 |
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committer | Mihai Moldovan <ionic@ionic.de> | 2017-03-07 22:34:09 +0100 |
commit | c6f0e6b2c6164b7a0c160222f4af8f45e97153c1 (patch) | |
tree | 741bdcc3a30b7b2e23a57c377ca057db38803129 /nx-X11/programs/Xserver/os/timingsafe_memcmp.c | |
parent | 05aabb4e6f45bcb2c951ec04026f9d7bce7335b3 (diff) | |
parent | 22f542626cf9935fd55a899e21144111e481542c (diff) | |
download | nx-libs-c6f0e6b2c6164b7a0c160222f4af8f45e97153c1.tar.gz nx-libs-c6f0e6b2c6164b7a0c160222f4af8f45e97153c1.tar.bz2 nx-libs-c6f0e6b2c6164b7a0c160222f4af8f45e97153c1.zip |
Merge branch 'uli42-pr/cve-2017-2624' into 3.6.x
Attributes GH PR #380: https://github.com/ArcticaProject/nx-libs/pull/380
Fixes: ArcticaProject/nx-libs#365.
Diffstat (limited to 'nx-X11/programs/Xserver/os/timingsafe_memcmp.c')
-rw-r--r-- | nx-X11/programs/Xserver/os/timingsafe_memcmp.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/nx-X11/programs/Xserver/os/timingsafe_memcmp.c b/nx-X11/programs/Xserver/os/timingsafe_memcmp.c new file mode 100644 index 000000000..fe87de7bc --- /dev/null +++ b/nx-X11/programs/Xserver/os/timingsafe_memcmp.c @@ -0,0 +1,47 @@ +/* + * Copyright (c) 2014 Google Inc. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <limits.h> +#include <string.h> +#include <nx-X11/Xfuncproto.h> +#include "os.h" + +int +timingsafe_memcmp(const void *b1, const void *b2, size_t len) +{ + const unsigned char *p1 = b1, *p2 = b2; + size_t i; + int res = 0, done = 0; + + for (i = 0; i < len; i++) { + /* lt is -1 if p1[i] < p2[i]; else 0. */ + int lt = (p1[i] - p2[i]) >> CHAR_BIT; + + /* gt is -1 if p1[i] > p2[i]; else 0. */ + int gt = (p2[i] - p1[i]) >> CHAR_BIT; + + /* cmp is 1 if p1[i] > p2[i]; -1 if p1[i] < p2[i]; else 0. */ + int cmp = lt - gt; + + /* set res = cmp if !done. */ + res |= cmp & ~done; + + /* set done if p1[i] != p2[i]. */ + done |= lt | gt; + } + + return (res); +} |