LIBFMSR  0.1
gf.h
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00001 
00007 /* ===================================================================
00008 Copyright (c) 2013, Henry C. H. Chen
00009 All rights reserved.
00010 
00011 Redistribution and use in source and binary forms, with or without
00012 modification, are permitted provided that the following conditions are
00013 met:
00014 
00015   - Redistributions of source code must retain the above copyright
00016     notice, this list of conditions and the following disclaimer.
00017 
00018   - Redistributions in binary form must reproduce the above copyright
00019     notice, this list of conditions and the following disclaimer in
00020     the documentation and/or other materials provided with the
00021     distribution.
00022 
00023   - Neither the name of the Chinese University of Hong Kong nor the
00024     names of its contributors may be used to endorse or promote
00025     products derived from this software without specific prior written
00026     permission.
00027 
00028 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00029 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00030 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
00031 A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
00032 HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00033 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00034 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00035 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00036 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00037 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00038 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00039 =================================================================== */
00040 
00041 
00042 #ifndef LIBFMSR_GF_H
00043 #define LIBFMSR_GF_H
00044 
00045 #include <stdlib.h>
00046 
00047 #ifndef LIBFMSR_GF
00048 #define LIBFMSR_GF
00049 typedef unsigned char gf;
00050 #endif
00051 
00052 /*  ------------------------------------------------------------------  */
00053 /* | initialize all lookup tables (call first before doing anything!) | */
00054 /*  ------------------------------------------------------------------  */
00055 void gf_init(void);
00056 
00057 
00058 /*  --------------------------------  */
00059 /* | single table lookup operations | */
00060 /*  --------------------------------  */
00061 gf gf_mul(gf a, gf b);  // a*b
00062 gf gf_div(gf a, gf b);  // a/b, undefined for a=0 or b=0
00063 gf gf_inv(gf a);        // a^{-1}, undefined for a=0
00064 gf gf_log(gf a);        // log(a), undefined for a=0
00065 gf gf_x(gf a);          // x^a
00066 
00067 
00068 /*  ---------------------------------------------------------  */
00069 /* | multi-byte operations (faster than per-byte operations) | */
00070 /*  ---------------------------------------------------------  */
00073 void gf_mul_bytes(gf *a, size_t len, gf b, gf *c);
00074 
00077 void gf_mulxor_bytes(gf *a, size_t len, gf b, gf *c);
00078 
00079 
00080 #endif  /* LIBFMSR_GF_H */
00081 
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