security/nss/lib/freebl/mpi/utils/makeprime.c@b8a032363ba2 (annotated)
security/nss/lib/freebl/mpi/utils/makeprime.c
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| michael@0 | 1 | /* |
| michael@0 | 2 | * makeprime.c |
| michael@0 | 3 | * |
| michael@0 | 4 | * A simple prime generator function (and test driver). Prints out the |
| michael@0 | 5 | * first prime it finds greater than or equal to the starting value. |
| michael@0 | 6 | * |
| michael@0 | 7 | * Usage: makeprime <start> |
| michael@0 | 8 | * |
| michael@0 | 9 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 10 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 11 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 12 | |
| michael@0 | 13 | #include <stdio.h> |
| michael@0 | 14 | #include <stdlib.h> |
| michael@0 | 15 | #include <ctype.h> |
| michael@0 | 16 | |
| michael@0 | 17 | /* These two must be included for make_prime() to work */ |
| michael@0 | 18 | |
| michael@0 | 19 | #include "mpi.h" |
| michael@0 | 20 | #include "mpprime.h" |
| michael@0 | 21 | |
| michael@0 | 22 | /* |
| michael@0 | 23 | make_prime(p, nr) |
| michael@0 | 24 | |
| michael@0 | 25 | Find the smallest prime integer greater than or equal to p, where |
| michael@0 | 26 | primality is verified by 'nr' iterations of the Rabin-Miller |
| michael@0 | 27 | probabilistic primality test. The caller is responsible for |
| michael@0 | 28 | generating the initial value of p. |
| michael@0 | 29 | |
| michael@0 | 30 | Returns MP_OKAY if a prime has been generated, otherwise the error |
| michael@0 | 31 | code indicates some other problem. The value of p is clobbered; the |
| michael@0 | 32 | caller should keep a copy if the value is needed. |
| michael@0 | 33 | */ |
| michael@0 | 34 | mp_err make_prime(mp_int *p, int nr); |
| michael@0 | 35 | |
| michael@0 | 36 | /* The main() is not required -- it's just a test driver */ |
| michael@0 | 37 | int main(int argc, char *argv[]) |
| michael@0 | 38 | { |
| michael@0 | 39 | mp_int start; |
| michael@0 | 40 | mp_err res; |
| michael@0 | 41 | |
| michael@0 | 42 | if(argc < 2) { |
| michael@0 | 43 | fprintf(stderr, "Usage: %s <start-value>\n", argv[0]); |
| michael@0 | 44 | return 1; |
| michael@0 | 45 | } |
| michael@0 | 46 | |
| michael@0 | 47 | mp_init(&start); |
| michael@0 | 48 | if(argv[1][0] == '0' && tolower(argv[1][1]) == 'x') { |
| michael@0 | 49 | mp_read_radix(&start, argv[1] + 2, 16); |
| michael@0 | 50 | } else { |
| michael@0 | 51 | mp_read_radix(&start, argv[1], 10); |
| michael@0 | 52 | } |
| michael@0 | 53 | mp_abs(&start, &start); |
| michael@0 | 54 | |
| michael@0 | 55 | if((res = make_prime(&start, 5)) != MP_OKAY) { |
| michael@0 | 56 | fprintf(stderr, "%s: error: %s\n", argv[0], mp_strerror(res)); |
| michael@0 | 57 | mp_clear(&start); |
| michael@0 | 58 | |
| michael@0 | 59 | return 1; |
| michael@0 | 60 | |
| michael@0 | 61 | } else { |
| michael@0 | 62 | char *buf = malloc(mp_radix_size(&start, 10)); |
| michael@0 | 63 | |
| michael@0 | 64 | mp_todecimal(&start, buf); |
| michael@0 | 65 | printf("%s\n", buf); |
| michael@0 | 66 | free(buf); |
| michael@0 | 67 | |
| michael@0 | 68 | mp_clear(&start); |
| michael@0 | 69 | |
| michael@0 | 70 | return 0; |
| michael@0 | 71 | } |
| michael@0 | 72 | |
| michael@0 | 73 | } /* end main() */ |
| michael@0 | 74 | |
| michael@0 | 75 | /*------------------------------------------------------------------------*/ |
| michael@0 | 76 | |
| michael@0 | 77 | mp_err make_prime(mp_int *p, int nr) |
| michael@0 | 78 | { |
| michael@0 | 79 | mp_err res; |
| michael@0 | 80 | |
| michael@0 | 81 | if(mp_iseven(p)) { |
| michael@0 | 82 | mp_add_d(p, 1, p); |
| michael@0 | 83 | } |
| michael@0 | 84 | |
| michael@0 | 85 | do { |
| michael@0 | 86 | mp_digit which = prime_tab_size; |
| michael@0 | 87 | |
| michael@0 | 88 | /* First test for divisibility by a few small primes */ |
| michael@0 | 89 | if((res = mpp_divis_primes(p, &which)) == MP_YES) |
| michael@0 | 90 | continue; |
| michael@0 | 91 | else if(res != MP_NO) |
| michael@0 | 92 | goto CLEANUP; |
| michael@0 | 93 | |
| michael@0 | 94 | /* If that passes, try one iteration of Fermat's test */ |
| michael@0 | 95 | if((res = mpp_fermat(p, 2)) == MP_NO) |
| michael@0 | 96 | continue; |
| michael@0 | 97 | else if(res != MP_YES) |
| michael@0 | 98 | goto CLEANUP; |
| michael@0 | 99 | |
| michael@0 | 100 | /* If that passes, run Rabin-Miller as often as requested */ |
| michael@0 | 101 | if((res = mpp_pprime(p, nr)) == MP_YES) |
| michael@0 | 102 | break; |
| michael@0 | 103 | else if(res != MP_NO) |
| michael@0 | 104 | goto CLEANUP; |
| michael@0 | 105 | |
| michael@0 | 106 | } while((res = mp_add_d(p, 2, p)) == MP_OKAY); |
| michael@0 | 107 | |
| michael@0 | 108 | CLEANUP: |
| michael@0 | 109 | return res; |
| michael@0 | 110 | |
| michael@0 | 111 | } /* end make_prime() */ |
| michael@0 | 112 | |
| michael@0 | 113 | /*------------------------------------------------------------------------*/ |
| michael@0 | 114 | /* HERE THERE BE DRAGONS */ |
