diff options
Diffstat (limited to 'srtp/crypto/math/gf2_8.c')
-rw-r--r-- | srtp/crypto/math/gf2_8.c | 83 |
1 files changed, 0 insertions, 83 deletions
diff --git a/srtp/crypto/math/gf2_8.c b/srtp/crypto/math/gf2_8.c deleted file mode 100644 index 8a112ba..0000000 --- a/srtp/crypto/math/gf2_8.c +++ /dev/null @@ -1,83 +0,0 @@ -/* - * gf2_8.c - * - * GF(256) finite field implementation, with the representation used - * in the AES cipher. - * - * David A. McGrew - * Cisco Systems, Inc. - */ - -/* - * - * Copyright (c) 2001-2006, Cisco Systems, Inc. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - * Redistributions in binary form must reproduce the above - * copyright notice, this list of conditions and the following - * disclaimer in the documentation and/or other materials provided - * with the distribution. - * - * Neither the name of the Cisco Systems, Inc. nor the names of its - * contributors may be used to endorse or promote products derived - * from this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, - * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES - * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR - * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, - * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED - * OF THE POSSIBILITY OF SUCH DAMAGE. - * - */ - - -#include "datatypes.h" -#include "gf2_8.h" - -/* gf2_8_shift() moved to gf2_8.h as an inline function */ - -inline gf2_8 -gf2_8_multiply(gf2_8 x, gf2_8 y) { - gf2_8 z = 0; - - if (y & 1) z ^= x; x = gf2_8_shift(x); - if (y & 2) z ^= x; x = gf2_8_shift(x); - if (y & 4) z ^= x; x = gf2_8_shift(x); - if (y & 8) z ^= x; x = gf2_8_shift(x); - if (y & 16) z ^= x; x = gf2_8_shift(x); - if (y & 32) z ^= x; x = gf2_8_shift(x); - if (y & 64) z ^= x; x = gf2_8_shift(x); - if (y & 128) z ^= x; - - return z; -} - - -/* this should use the euclidean algorithm */ - -gf2_8 -gf2_8_compute_inverse(gf2_8 x) { - unsigned int i; - - if (x == 0) return 0; /* zero is a special case */ - for (i=0; i < 256; i++) - if (gf2_8_multiply((gf2_8) i, x) == 1) - return (gf2_8) i; - - return 0; -} - |