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Diffstat (limited to 'contrib/bind9/lib/isc/include/isc/hash.h')
| -rw-r--r-- | contrib/bind9/lib/isc/include/isc/hash.h | 175 |
1 files changed, 0 insertions, 175 deletions
diff --git a/contrib/bind9/lib/isc/include/isc/hash.h b/contrib/bind9/lib/isc/include/isc/hash.h deleted file mode 100644 index b94142b48e20..000000000000 --- a/contrib/bind9/lib/isc/include/isc/hash.h +++ /dev/null @@ -1,175 +0,0 @@ -/* - * Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") - * Copyright (C) 2003 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: hash.h,v 1.2.2.1.2.2 2004/03/06 08:14:41 marka Exp $ */ - -#ifndef ISC_HASH_H -#define ISC_HASH_H 1 - -/***** - ***** Module Info - *****/ - -/* - * Hash - * - * The hash API - * - * Provides an unpredictable hash value for variable length data. - * A hash object contains a random vector (which is hidden from clients - * of this API) to make the actual hash value unpredictable. - * - * The algorithm used in the API guarantees the probability of hash - * collision; in the current implementation, as long as the values stored - * in the random vector are unpredictable, the probability of hash - * collision between arbitrary two different values is at most 1/2^16. - * - * Altough the API is generic about the hash keys, it mainly expects - * DNS names (and sometimes IPv4/v6 addresses) as inputs. It has an - * upper limit of the input length, and may run slow to calculate the - * hash values for large inputs. - * - * This API is designed to be general so that it can provide multiple - * different hash contexts that have different random vectors. However, - * it should be typical to have a single context for an entire system. - * To support such cases, the API also provides a single-context mode. - * - * MP: - * The hash object is almost read-only. Once the internal random vector - * is initialized, no write operation will occur, and there will be no - * need to lock the object to calculate actual hash values. - * - * Reliability: - * In some cases this module uses low-level data copy to initialize the - * random vector. Errors in this part are likely to crash the server or - * corrupt memory. - * - * Resources: - * A buffer, used as a random vector for calculating hash values. - * - * Security: - * This module intends to provide unpredictable hash values in - * adversarial environments in order to avoid denial of service attacks - * to hash buckets. - * Its unpredictability relies on the quality of entropy to build the - * random vector. - * - * Standards: - * None. - */ - -/*** - *** Imports - ***/ - -#include <isc/types.h> - -/*** - *** Functions - ***/ -ISC_LANG_BEGINDECLS - -isc_result_t -isc_hash_ctxcreate(isc_mem_t *mctx, isc_entropy_t *entropy, unsigned int limit, - isc_hash_t **hctx); -isc_result_t -isc_hash_create(isc_mem_t *mctx, isc_entropy_t *entropy, size_t limit); -/* - * Create a new hash object. - * - * isc_hash_ctxcreate() creates a different object. - * isc_hash_create() creates a module-internal object to support the - * single-context mode. It should be called only once. - * - * 'entropy' must be NULL or a valid entropy object. If 'entropy' is NULL, - * pseudo random values will be used to build the random vector, which may - * weaken security. - * - * 'limit' specifies the maximum number of hash keys. If it is too large, - * these functions may fail. - */ - -void -isc_hash_ctxattach(isc_hash_t *hctx, isc_hash_t **hctxp); -/* - * Attach to a hash object. - * This function is only necessary for the multiple-context mode. - */ - -void -isc_hash_ctxdetach(isc_hash_t **hctxp); -/* - * Detach from a hash object. - * - * This function is for the multiple-context mode, and takes a valid - * hash object as an argument. - */ - -void -isc_hash_destroy(void); -/* - * This function is for the single-context mode, and is expected to be used - * as a counterpart of isc_hash_create(). - * A valid module-internal hash object must have been created, and this - * function should be called only once. - */ - -void -isc_hash_ctxinit(isc_hash_t *hctx); -void -isc_hash_init(void); -/* - * Initialize a hash object. It fills in the random vector with a proper - * source of entropy, which is typically from the entropy object specified - * at the creation. Thus, it is desirable to call these functions after - * initializing the entropy object with some good entropy sources. - * - * These functions should be called before the first hash calculation. - * - * isc_hash_ctxinit() is for the multiple-context mode, and takes a valid hash - * object as an argument. - * isc_hash_init() is for the single-context mode. A valid module-internal - * hash object must have been created, and this function should be called only - * once. - */ - -unsigned int -isc_hash_ctxcalc(isc_hash_t *hctx, const unsigned char *key, - unsigned int keylen, isc_boolean_t case_sensitive); -unsigned int -isc_hash_calc(const unsigned char *key, unsigned int keylen, - isc_boolean_t case_sensitive); -/* - * Calculate a hash value. - * - * isc_hash_ctxinit() is for the multiple-context mode, and takes a valid hash - * object as an argument. - * isc_hash_init() is for the single-context mode. A valid module-internal - * hash object must have been created. - * - * 'key' is the hash key, which is a variable length buffer. - * 'keylen' specifies the key length, which must not be larger than the limit - * specified for the corresponding hash object. - * - * 'case_sensitive' specifies whether the hash key should be treated as - * case_sensitive values. It should typically be ISC_FALSE if the hash key - * is a DNS name. - */ - -ISC_LANG_ENDDECLS - -#endif /* ISC_HASH_H */ |