diff options
Diffstat (limited to 'contrib/bind9/lib/isc/include/isc/lfsr.h')
| -rw-r--r-- | contrib/bind9/lib/isc/include/isc/lfsr.h | 59 |
1 files changed, 28 insertions, 31 deletions
diff --git a/contrib/bind9/lib/isc/include/isc/lfsr.h b/contrib/bind9/lib/isc/include/isc/lfsr.h index e562380..0c2e845 100644 --- a/contrib/bind9/lib/isc/include/isc/lfsr.h +++ b/contrib/bind9/lib/isc/include/isc/lfsr.h @@ -1,5 +1,5 @@ /* - * Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") + * 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 @@ -15,17 +15,19 @@ * PERFORMANCE OF THIS SOFTWARE. */ -/* $Id: lfsr.h,v 1.10.206.1 2004/03/06 08:14:43 marka Exp $ */ +/* $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". * @@ -36,96 +38,91 @@ typedef struct isc_lfsr isc_lfsr_t; */ 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_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 -/* - * In all these functions it is important that the caller only use as many - * bits as the LFSR has state. Also, it isn't guaranteed that an LFSR of - * bit length 32 will have 2^32 unique states before repeating. - */ 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: * - * Putting untrusted values into this function will cause the LFSR to + *\li Putting untrusted values into this function will cause the LFSR to * generate (perhaps) non-maximal length sequences. * * Requires: * - * lfsr != NULL + *\li lfsr != NULL * - * 8 <= bits <= 32 + *\li 8 <= bits <= 32 * - * tap != 0 + *\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: * - * lfsr be valid. + *\li lfsr be valid. * - * data != NULL. + *\li data != NULL. * - * count > 0. + *\li count > 0. */ void isc_lfsr_skip(isc_lfsr_t *lfsr, unsigned int skip); -/* +/*%< * Skip "skip" states. * * Requires: * - * lfsr be valid. + *\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: * - * This function is used only for very, very low security data, such + *\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: * - * Since the current state from each of the LFSRs is used to skip + *\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: * - * lfsr1 and lfsr2 be valid. + *\li lfsr1 and lfsr2 be valid. * - * 1 <= skipbits <= 31 + *\li 1 <= skipbits <= 31 */ ISC_LANG_ENDDECLS |
