From b3daeff2bc9d451afc9c311034a122c6495cc1ab Mon Sep 17 00:00:00 2001 From: bg Date: Tue, 13 Jan 2009 20:23:50 +0000 Subject: [PATCH] little helper for generating multiplication tables for multiplication in GF(2**8) --- host/gf256_table_gen.c | 153 +++++++++++++++++++++++++++++++++++++++++ host/gf256mul.c | 42 +++++++++++ host/gf256mul.h | 29 ++++++++ 3 files changed, 224 insertions(+) create mode 100644 host/gf256_table_gen.c create mode 100644 host/gf256mul.c create mode 100644 host/gf256mul.h diff --git a/host/gf256_table_gen.c b/host/gf256_table_gen.c new file mode 100644 index 0000000..87887d6 --- /dev/null +++ b/host/gf256_table_gen.c @@ -0,0 +1,153 @@ +/* gf256_table_gen.c */ +/* + This file is part of the Crypto-avr-lib/microcrypt-lib. + Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +*/ +/** + * \file gf256_table_gen.c + * \email daniel.otte@rub.de + * \author Daniel Otte + * \date 2009-01-13 + * \license GPLv3 or later + * + */ +#include +#include +#include +#include +#include "gf256mul.h" + +int print_header = 1, + print_braces = 1, + print_base = 1, + print_align = 1, + print_prefix = 1; + +char* fmt_strings[]={"%d", "%3d", + "%X", "%2.2X", + "%o", "%3o", + "%d", "%3d", + "0x%X", "0x%2.2X", + "0%o", "0%3o"}; + +int main(int argc, char** argv){ + int i,j; + int c; + int option_index=0; + char* fmt=NULL; + static struct option long_options[] = + { + /* These options set a flag. */ + {"print-header", no_argument, &print_header, 1}, + {"no-print-header", no_argument, &print_header, 0}, + {"print-braces", no_argument, &print_braces, 1}, + {"no-print-braces", no_argument, &print_braces, 0}, + {"print-dec", no_argument, &print_base, 0}, + {"print-hex", no_argument, &print_base, 1}, + {"print-octal", no_argument, &print_base, 2}, + {"align", no_argument, &print_align, 1}, + {"no-align", no_argument, &print_align, 0}, + {"print-prefix", no_argument, &print_prefix, 1}, + {"no-print-prefix", no_argument, &print_prefix, 0}, + + /* These options don't set a flag. + We distinguish them by their indices. */ + {"reducer", required_argument, 0, 'r'}, + {"min", required_argument, 0, 'l'}, + {"max", required_argument, 0, 'u'}, + {"format", required_argument, 0, 'f'}, + {0, 0, 0, 0} + }; + + + + unsigned long ul_a; + int columns=8; + unsigned long ul_reducer=0x1b, max=0xff, min=0x00; + uint8_t reducer, a; + char** eptr; + FILE* of = stdout; + while(c!=-1){ + c = getopt_long(argc, argv,"cCbBdhoaApPr:l:u:f:", + long_options, &option_index); + switch(c){ + case 'c': print_header=1; break; + case 'C': print_header=0; break; + case 'b': print_braces=1; break; + case 'B': print_braces=0; break; + case 'h': print_base = 1; break; + case 'd': print_base = 0; break; + case 'o': print_base = 2; break; + case 'a': print_align =1; break; + case 'A': print_align =0; break; + case 'p': print_prefix=1; break; + case 'P': print_prefix=0; break; + case 'r': ul_reducer = strtoul(optarg, eptr, 0); + if((**eptr)!='\0'){ + fprintf(stderr, "Error, invalid reducer value \"%s\"!\n", + optarg); + return -1; + } + break; + case 'l': min = strtoul(optarg, eptr, 0); + if(((**eptr)!='\0')||min>0xff){ + fprintf(stderr, "Error, invalid minimum value \"%s\"!\n", + optarg); + return -1; + } + break; + case 'u': max = strtoul(optarg, eptr, 0); + if(((**eptr)!='\0')||max>0xff){ + fprintf(stderr, "Error, invalid maximum value \"%s\"!\n", + optarg); + return -1; + } + break; + case 'f': fmt = optarg; break; + default: break; + } + } + reducer = ul_reducer&0xff; + if(!fmt) + fmt = fmt_strings[print_prefix*6+print_base*2+print_align]; + + for(i=optind; i0xff){ + fprintf(stderr, "Error, invalid number \"%s\"!\n", argv[i]); + return -1; + } + a = ul_a; + if(print_header) + fprintf(of,"\nuint8_t lut_gfmul_%s_%2.2x",argv[i],reducer); + if(print_braces) + fprintf(of," = {\n\t"); + + for(j=min; j<=max-1; ++j){ + fprintf(of,fmt,gf256mul(a, j, reducer)); + if(j%columns==columns-1){ + fprintf(of, ",\n\t"); + }else{ + fprintf(of, ", "); + } + } + fprintf(of, fmt, gf256mul(a,max, reducer)); + if(print_braces) + fprintf(of, " }"); + fprintf(of, "\n\n"); + } + return 0; +} diff --git a/host/gf256mul.c b/host/gf256mul.c new file mode 100644 index 0000000..3da67cb --- /dev/null +++ b/host/gf256mul.c @@ -0,0 +1,42 @@ +/* gf256mul.c */ +/* + This file is part of the Crypto-avr-lib/microcrypt-lib. + Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +*/ +/** + * \file gf256mul.c + * \email daniel.otte@rub.de + * \author Daniel Otte + * \date 2009-01-13 + * \license GPLv3 or later + * + */ +#include +#include "gf256mul.h" + +uint8_t gf256mul(uint8_t a, uint8_t b, uint8_t reducer){ + uint8_t t,ret=0; + while(a){ + if(a&1) + ret ^= b; + t=a&0x80; + b<<=1; + if(t) + b^=reducer; + a>>=1; + } + return ret; +} diff --git a/host/gf256mul.h b/host/gf256mul.h new file mode 100644 index 0000000..f1a61bb --- /dev/null +++ b/host/gf256mul.h @@ -0,0 +1,29 @@ +/* gf256mul.h */ +/* + This file is part of the Crypto-avr-lib/microcrypt-lib. + Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +*/ +/** + * \file gf256mul.h + * \email daniel.otte@rub.de + * \author Daniel Otte + * \date 2009-01-13 + * \license GPLv3 or later + * + */ +#include + +uint8_t gf256mul(uint8_t a, uint8_t b, uint8_t reducer); -- 2.39.2