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Diffstat (limited to 'src/reducer/validation_IT_CF.c')
| -rw-r--r-- | src/reducer/validation_IT_CF.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/src/reducer/validation_IT_CF.c b/src/reducer/validation_IT_CF.c new file mode 100644 index 0000000..ecdad90 --- /dev/null +++ b/src/reducer/validation_IT_CF.c @@ -0,0 +1,198 @@ +/* + This file is part of Anastasis + Copyright (C) 2021 Taler Systems SA + + Anastasis is free software; you can redistribute it and/or modify it under the + terms of the GNU Lesser General Public License as published by the Free Software + Foundation; either version 3, or (at your option) any later version. + + Anastasis 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 + Anastasis; see the file COPYING.GPL. If not, see <http://www.gnu.org/licenses/> +*/ +/** + * @file redux/validation_IT_CF.c + * @brief validation of Italian Code Fiscales + * @author Christian Grothoff + */ +#include <string.h> +#include <stdbool.h> +#include <stdio.h> +#include <math.h> + +struct MapEntry +{ + char in; + unsigned int out; +}; + + +static const struct MapEntry odd[] = { + { '0', 1}, + { '9', 21}, + { 'I', 19 }, + { 'R', 8}, + { '1', 0}, + { 'A', 1}, + { 'J', 21}, + { 'S', 12}, + {'2', 5}, + {'B', 0}, + {'K', 2}, + {'T', 14}, + {'3', 7}, + {'C', 5}, + {'L', 4}, + {'U', 16}, + {'4', 9}, + {'D', 7}, + {'M', 18}, + {'V', 10}, + {'5', 13}, + {'E', 9}, + {'N', 20}, + {'W', 22}, + {'6', 15}, + {'F', 13}, + {'O', 11}, + {'X', 25}, + {'7', 17}, + {'G', 15}, + {'P', 3}, + {'Y', 24}, + {'8', 19}, + {'H', 17}, + {'Q', 6}, + {'Z', 23}, + {'\0', 0} +}; + + +static const struct MapEntry even[] = { + { '0', 0}, + { '1', 1}, + { '2', 2 }, + { '3', 3}, + { '4', 4}, + { '5', 5}, + { '6', 6 }, + { '7', 7 }, + {'8', 8}, + {'9', 9}, + {'A', 0}, + {'B', 1}, + {'C', 2}, + {'D', 3}, + {'E', 4}, + {'F', 5}, + {'G', 6}, + {'H', 7}, + {'I', 8}, + {'J', 9}, + {'K', 10}, + {'L', 11}, + {'M', 12}, + {'N', 13}, + {'O', 14}, + {'P', 15}, + {'Q', 16}, + {'R', 17}, + {'S', 18}, + {'T', 19}, + {'U', 20}, + {'V', 21}, + {'W', 22}, + {'X', 23}, + {'Y', 24}, + {'Z', 25}, + {'\0', 0} +}; + + +static const struct MapEntry rem[] = { + {'A', 0}, + {'B', 1}, + {'C', 2}, + {'D', 3}, + {'E', 4}, + {'F', 5}, + {'G', 6}, + {'H', 7}, + {'I', 8}, + {'J', 9}, + {'K', 10}, + {'L', 11}, + {'M', 12}, + {'N', 13}, + {'O', 14}, + {'P', 15}, + {'Q', 16}, + {'R', 17}, + {'S', 18}, + {'T', 19}, + {'U', 20}, + {'V', 21}, + {'W', 22}, + {'X', 23}, + {'Y', 24}, + {'Z', 25}, + {'\0', 0} +}; + + +/** + * Lookup @a in in @a map. Set @a fail to true if @a in is not found. + * + * @param map character map to search + * @param in character to search for + * @param[out] fail set to true on error + * @return map value, 0 on error + */ +static unsigned int +lookup (const struct MapEntry *map, + char in, + bool *fail) +{ + for (unsigned int i = 0; '\0' != map[i].in; i++) + if (in == map[i].in) + return map[i].out; + *fail = true; + return 0; +} + + +/** + * Function to validate an italian code fiscale number. + * See https://en.wikipedia.org/wiki/Italian_fiscal_code + * + * @param cf_number square number to validate (input) + * @return true if @a cf_number is a valid, else false + */ +bool +IT_CF_check (const char *cf_number) +{ + unsigned int sum = 0; + bool fail = false; + + if (strlen (cf_number) != 16) + return false; + for (unsigned int i = 0; i<15; i += 2) + sum += lookup (odd, + cf_number[i], + &fail); + for (unsigned int i = 1; i<15; i += 2) + sum += lookup (even, + cf_number[i], + &fail); + sum %= 26; + if (sum != lookup (rem, + cf_number[15], + &fail)) + return false; + if (fail) + return false; + return true; +} |