diff options
Diffstat (limited to 'nx-X11')
| -rw-r--r-- | nx-X11/programs/Xserver/include/os.h | 5 | ||||
| -rw-r--r-- | nx-X11/programs/Xserver/os/Imakefile | 4 | ||||
| -rw-r--r-- | nx-X11/programs/Xserver/os/mitauth.c | 2 | ||||
| -rw-r--r-- | nx-X11/programs/Xserver/os/timingsafe_memcmp.c | 47 |
4 files changed, 55 insertions, 3 deletions
diff --git a/nx-X11/programs/Xserver/include/os.h b/nx-X11/programs/Xserver/include/os.h index 59ace8fd2..0fd687d18 100644 --- a/nx-X11/programs/Xserver/include/os.h +++ b/nx-X11/programs/Xserver/include/os.h @@ -460,6 +460,11 @@ extern _X_EXPORT size_t strlcat(char *dst, const char *src, size_t siz); #endif +#ifndef HAVE_TIMINGSAFE_MEMCMP +extern _X_EXPORT int +timingsafe_memcmp(const void *b1, const void *b2, size_t len); +#endif + /* Logging. */ typedef enum _LogParameter { XLOG_FLUSH, diff --git a/nx-X11/programs/Xserver/os/Imakefile b/nx-X11/programs/Xserver/os/Imakefile index 2abc1aff9..787a9ef2c 100644 --- a/nx-X11/programs/Xserver/os/Imakefile +++ b/nx-X11/programs/Xserver/os/Imakefile @@ -120,12 +120,12 @@ BOOTSTRAPCFLAGS = osinit.c utils.c log.c auth.c mitauth.c secauth.c \ $(XDMAUTHSRCS) $(RPCSRCS) xdmcp.c OtherSources \ xstrans.c $(SNPRINTF_SRCS) $(STRLCAT_SRCS) \ - $(REALLOCARRAY_SRCS) xprintf.c + $(REALLOCARRAY_SRCS) xprintf.c timingsafe_memcmp.c OBJS = WaitFor.o access.o connection.o io.o $(COLOR_OBJS) \ osinit.o utils.o log.o auth.o mitauth.o secauth.o \ $(XDMAUTHOBJS) $(RPCOBJS) xdmcp.o OtherObjects \ xstrans.o $(SNPRINTF_OBJS) $(STRLCAT_OBJS) \ - $(REALLOCARRAY_OBJS) xprintf.o + $(REALLOCARRAY_OBJS) xprintf.o timingsafe_memcmp.o #if UseMemLeak MEM_DEFINES = -DMEMBUG diff --git a/nx-X11/programs/Xserver/os/mitauth.c b/nx-X11/programs/Xserver/os/mitauth.c index c42cbe30e..578f8ba42 100644 --- a/nx-X11/programs/Xserver/os/mitauth.c +++ b/nx-X11/programs/Xserver/os/mitauth.c @@ -82,7 +82,7 @@ MitCheckCookie ( for (auth = mit_auth; auth; auth=auth->next) { if (data_length == auth->len && - memcmp (data, auth->data, (int) data_length) == 0) + timingsafe_memcmp (data, auth->data, (int) data_length) == 0) return auth->id; } *reason = "Invalid MIT-MAGIC-COOKIE-1 key"; 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); +} |