1 /* $Id$ */ 2 /* 3 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) 4 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 */ 20 #ifndef __PJLIB_UTIL_CRC32_H__ 21 #define __PJLIB_UTIL_CRC32_H__ 22 23 /** 24 * @file crc32.h 25 * @brief CRC32 implementation 26 */ 27 28 #include <pjlib-util/types.h> 29 30 PJ_BEGIN_DECL 31 32 /** 33 * @defgroup PJLIB_UTIL_CRC32 CRC32 (Cyclic Redundancy Check) 34 * @ingroup PJLIB_UTIL_ENCRYPTION 35 * @{ 36 * This implements CRC32 algorithm. See ITU-T V.42 for the formal 37 * specification. 38 */ 39 40 /** CRC32 context. */ 41 typedef struct pj_crc32_context 42 { 43 pj_uint32_t crc_state; /**< Current state. */ 44 } pj_crc32_context; 45 46 47 /** 48 * Initialize CRC32 context. 49 * 50 * @param ctx CRC32 context. 51 */ 52 PJ_DECL(void) pj_crc32_init(pj_crc32_context *ctx); 53 54 /** 55 * Feed data incrementally to the CRC32 algorithm. 56 * 57 * @param ctx CRC32 context. 58 * @param data Input data. 59 * @param nbytes Length of the input data. 60 * 61 * @return The current CRC32 value. 62 */ 63 PJ_DECL(pj_uint32_t) pj_crc32_update(pj_crc32_context *ctx, 64 const pj_uint8_t *data, 65 pj_size_t nbytes); 66 67 /** 68 * Finalize CRC32 calculation and retrieve the CRC32 value. 69 * 70 * @param ctx CRC32 context. 71 * 72 * @return The current CRC value. 73 */ 74 PJ_DECL(pj_uint32_t) pj_crc32_final(pj_crc32_context *ctx); 75 76 /** 77 * Perform one-off CRC32 calculation to the specified data. 78 * 79 * @param data Input data. 80 * @param nbytes Length of input data. 81 * 82 * @return CRC value of the data. 83 */ 84 PJ_DECL(pj_uint32_t) pj_crc32_calc(const pj_uint8_t *data, 85 pj_size_t nbytes); 86 87 88 /** 89 * @} 90 */ 91 92 PJ_END_DECL 93 94 95 #endif /* __PJLIB_UTIL_CRC32_H__ */ 96 97