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Diffstat (limited to 'src/crypto/isa-l/isa-l_crypto/include/rolling_hashx.h')
| -rw-r--r-- | src/crypto/isa-l/isa-l_crypto/include/rolling_hashx.h | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/src/crypto/isa-l/isa-l_crypto/include/rolling_hashx.h b/src/crypto/isa-l/isa-l_crypto/include/rolling_hashx.h new file mode 100644 index 000000000..035cf1701 --- /dev/null +++ b/src/crypto/isa-l/isa-l_crypto/include/rolling_hashx.h @@ -0,0 +1,114 @@ +/********************************************************************** + Copyright(c) 2011-2017 Intel Corporation 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 Intel Corporation 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 + OWNER 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. +**********************************************************************/ + +/** + * @file rolling_hashx.h + * @brief Fingerprint functions based on rolling hash + * + * rolling_hash2 - checks hash in a sliding window based on random 64-bit hash. + */ + +#ifndef _ROLLING_HASHX_H_ +#define _ROLLING_HASHX_H_ + +#ifdef __cplusplus +extern "C" { +#endif + +#include <stdint.h> + +/** + *@brief rolling hash return values + */ +enum { + FINGERPRINT_RET_HIT = 0, //!< Fingerprint trigger hit + FINGERPRINT_RET_MAX, //!< Fingerprint max length reached before hit + FINGERPRINT_RET_OTHER //!< Fingerprint function error returned +}; + +#define FINGERPRINT_MAX_WINDOW 48 + +/** + * @brief Context for rolling_hash2 functions + */ +struct rh_state2 { + uint8_t history[FINGERPRINT_MAX_WINDOW]; + uint64_t table1[256]; + uint64_t table2[256]; + uint64_t hash; + uint32_t w; +}; + +/** + * @brief Initialize state object for rolling hash2 + * + * @param state Structure holding state info on current rolling hash + * @param w Window width (1 <= w <= 32) + * @returns 0 - success, -1 - failure + */ +int rolling_hash2_init(struct rh_state2 *state, uint32_t w); + +/** + * @brief Reset the hash state history + * + * @param state Structure holding state info on current rolling hash + * @param init_bytes Optional window size buffer to pre-init hash + * @returns none + */ +void rolling_hash2_reset(struct rh_state2 *state, uint8_t * init_bytes); + +/** + * @brief Run rolling hash function until trigger met or max length reached + * + * Checks for trigger based on a random hash in a sliding window. + * @param state Structure holding state info on current rolling hash + * @param buffer Pointer to input buffer to run windowed hash on + * @param max_len Max length to run over input + * @param mask Mask bits ORed with hash before test with trigger + * @param trigger Match value to compare with windowed hash at each input byte + * @param offset Offset from buffer to match, set if match found + * @returns FINGERPRINT_RET_HIT - match found, FINGERPRINT_RET_MAX - exceeded max length + */ +int rolling_hash2_run(struct rh_state2 *state, uint8_t * buffer, uint32_t max_len, + uint32_t mask, uint32_t trigger, uint32_t * offset); + +/** + * @brief Generate an appropriate mask to target mean hit rate + * + * @param mean Target chunk size in bytes + * @param shift Bits to rotate result to get independent masks + * @returns 32-bit mask value + */ +uint32_t rolling_hashx_mask_gen(long mean, int shift); + +#ifdef __cplusplus +} +#endif + +#endif // _ROLLING_HASHX_H_ |