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Diffstat (limited to 'contrib/bind9/lib/isc/include/isc/lfsr.h')
| -rw-r--r-- | contrib/bind9/lib/isc/include/isc/lfsr.h | 130 |
1 files changed, 0 insertions, 130 deletions
diff --git a/contrib/bind9/lib/isc/include/isc/lfsr.h b/contrib/bind9/lib/isc/include/isc/lfsr.h deleted file mode 100644 index 0c2e845..0000000 --- a/contrib/bind9/lib/isc/include/isc/lfsr.h +++ /dev/null @@ -1,130 +0,0 @@ -/* - * Copyright (C) 2004, 2005 Internet Systems Consortium, Inc. ("ISC") - * Copyright (C) 1999-2001 Internet Software Consortium. - * - * 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 ISC DISCLAIMS ALL WARRANTIES WITH - * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY - * AND FITNESS. IN NO EVENT SHALL ISC 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. - */ - -/* $Id: lfsr.h,v 1.11.18.2 2005/04/29 00:16:56 marka Exp $ */ - -#ifndef ISC_LFSR_H -#define ISC_LFSR_H 1 - -/*! \file */ - -#include <isc/lang.h> -#include <isc/types.h> - -typedef struct isc_lfsr isc_lfsr_t; - -/*% - * This function is called when reseeding is needed. It is allowed to - * modify any state in the LFSR in any way it sees fit OTHER THAN "bits". - * - * It MUST set "count" to a new value or the lfsr will never reseed again. - * - * Also, a reseed will never occur in the middle of an extraction. This - * is purely an optimization, and is probably what one would want. - */ -typedef void (*isc_lfsrreseed_t)(isc_lfsr_t *, void *); - -/*% - * The members of this structure can be used by the application, but care - * needs to be taken to not change state once the lfsr is in operation. - */ -struct isc_lfsr { - isc_uint32_t state; /*%< previous state */ - unsigned int bits; /*%< length */ - isc_uint32_t tap; /*%< bit taps */ - unsigned int count; /*%< reseed count (in BITS!) */ - isc_lfsrreseed_t reseed; /*%< reseed function */ - void *arg; /*%< reseed function argument */ -}; - -ISC_LANG_BEGINDECLS - - -void -isc_lfsr_init(isc_lfsr_t *lfsr, isc_uint32_t state, unsigned int bits, - isc_uint32_t tap, unsigned int count, - isc_lfsrreseed_t reseed, void *arg); -/*%< - * Initialize an LFSR. - * - * Note: - * - *\li Putting untrusted values into this function will cause the LFSR to - * generate (perhaps) non-maximal length sequences. - * - * Requires: - * - *\li lfsr != NULL - * - *\li 8 <= bits <= 32 - * - *\li tap != 0 - */ - -void -isc_lfsr_generate(isc_lfsr_t *lfsr, void *data, unsigned int count); -/*%< - * Returns "count" bytes of data from the LFSR. - * - * Requires: - * - *\li lfsr be valid. - * - *\li data != NULL. - * - *\li count > 0. - */ - -void -isc_lfsr_skip(isc_lfsr_t *lfsr, unsigned int skip); -/*%< - * Skip "skip" states. - * - * Requires: - * - *\li lfsr be valid. - */ - -isc_uint32_t -isc_lfsr_generate32(isc_lfsr_t *lfsr1, isc_lfsr_t *lfsr2); -/*%< - * Given two LFSRs, use the current state from each to skip entries in the - * other. The next states are then xor'd together and returned. - * - * WARNING: - * - *\li This function is used only for very, very low security data, such - * as DNS message IDs where it is desired to have an unpredictable - * stream of bytes that are harder to predict than a simple flooding - * attack. - * - * Notes: - * - *\li Since the current state from each of the LFSRs is used to skip - * state in the other, it is important that no state be leaked - * from either LFSR. - * - * Requires: - * - *\li lfsr1 and lfsr2 be valid. - * - *\li 1 <= skipbits <= 31 - */ - -ISC_LANG_ENDDECLS - -#endif /* ISC_LFSR_H */ |
