69 lines
1.8 KiB
C
69 lines
1.8 KiB
C
/* $OpenBSD: timingsafe.c,v 1.3 2014/06/21 22:57:15 tedu Exp $ */
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/*
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* Copyright (c) 2014 Google Inc.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <assert.h>
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#include <stdlib.h>
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#include <string.h>
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#define ASSERT_EQ(a, b) assert((a) == (b))
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enum {
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N = 8
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};
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static unsigned char bufone[N], buftwo[N];
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void
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check()
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{
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int cmp = memcmp(bufone, buftwo, N);
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/* Check for reflexivity. */
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ASSERT_EQ(0, timingsafe_bcmp(bufone, bufone, N));
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ASSERT_EQ(0, timingsafe_bcmp(buftwo, buftwo, N));
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ASSERT_EQ(0, timingsafe_memcmp(bufone, bufone, N));
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ASSERT_EQ(0, timingsafe_memcmp(buftwo, buftwo, N));
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/* Check that timingsafe_bcmp returns 0 iff memcmp returns 0. */
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ASSERT_EQ(cmp == 0, timingsafe_bcmp(bufone, buftwo, N) == 0);
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/* Check that timingsafe_memcmp returns cmp... */
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ASSERT_EQ(cmp < 0, timingsafe_memcmp(bufone, buftwo, N) < 0);
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/* ... or -cmp if the argument order is swapped. */
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ASSERT_EQ(-cmp < 0, timingsafe_memcmp(buftwo, bufone, N) < 0);
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}
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int
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main()
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{
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int i, j;
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for (i = 0; i < 10000; i++) {
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arc4random_buf(bufone, N);
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arc4random_buf(buftwo, N);
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check();
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for (j = 0; j < N; j++) {
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buftwo[j] = bufone[j];
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check();
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}
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}
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return (0);
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}
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