1f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* Makes safe primes of a DR nature */ 2f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#include <tommath.h> 3f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 4f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Projectint sizes[] = { 1+256/DIGIT_BIT, 1+512/DIGIT_BIT, 1+768/DIGIT_BIT, 1+1024/DIGIT_BIT, 1+2048/DIGIT_BIT, 1+4096/DIGIT_BIT }; 5f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Projectint main(void) 6f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project{ 7f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project int res, x, y; 8f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project char buf[4096]; 9f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project FILE *out; 10f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_int a, b; 11f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 12f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_init(&a); 13f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_init(&b); 14f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 15f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project out = fopen("drprimes.txt", "w"); 16f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project for (x = 0; x < (int)(sizeof(sizes)/sizeof(sizes[0])); x++) { 17f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project top: 18f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project printf("Seeking a %d-bit safe prime\n", sizes[x] * DIGIT_BIT); 19f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_grow(&a, sizes[x]); 20f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_zero(&a); 21f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project for (y = 1; y < sizes[x]; y++) { 22f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project a.dp[y] = MP_MASK; 23f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 24f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 25f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* make a DR modulus */ 26f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project a.dp[0] = -1; 27f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project a.used = sizes[x]; 28f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 29f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* now loop */ 30f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project res = 0; 31f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project for (;;) { 32f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project a.dp[0] += 4; 33f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (a.dp[0] >= MP_MASK) break; 34f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_prime_is_prime(&a, 1, &res); 35f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (res == 0) continue; 36f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project printf("."); fflush(stdout); 37f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_sub_d(&a, 1, &b); 38f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_div_2(&b, &b); 39f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_prime_is_prime(&b, 3, &res); 40f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (res == 0) continue; 41f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_prime_is_prime(&a, 3, &res); 42f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (res == 1) break; 43f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 44f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 45f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (res != 1) { 46f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project printf("Error not DR modulus\n"); sizes[x] += 1; goto top; 47f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } else { 48f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_toradix(&a, buf, 10); 49f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project printf("\n\np == %s\n\n", buf); 50f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project fprintf(out, "%d-bit prime:\np == %s\n\n", mp_count_bits(&a), buf); fflush(out); 51f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 52f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 53f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project fclose(out); 54f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 55f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_clear(&a); 56f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_clear(&b); 57f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 58f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return 0; 59f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project} 60f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 61f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 62f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Source: /cvs/libtom/libtommath/etc/drprime.c,v $ */ 63f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Revision: 1.2 $ */ 64f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Date: 2005/05/05 14:38:47 $ */ 65