Diffstat (limited to 'pwmanager/libcrypt/mpi/mpi-gcd.c') (more/less context) (ignore whitespace changes)
-rw-r--r-- | pwmanager/libcrypt/mpi/mpi-gcd.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/pwmanager/libcrypt/mpi/mpi-gcd.c b/pwmanager/libcrypt/mpi/mpi-gcd.c new file mode 100644 index 0000000..51841e7 --- a/dev/null +++ b/pwmanager/libcrypt/mpi/mpi-gcd.c | |||
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1 | /* mpi-gcd.c - MPI functions | ||
2 | *Copyright (C) 1998, 2001, 2002, 2003 Free Software Foundation, Inc. | ||
3 | * | ||
4 | * This file is part of Libgcrypt. | ||
5 | * | ||
6 | * Libgcrypt is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU Lesser General Public License as | ||
8 | * published by the Free Software Foundation; either version 2.1 of | ||
9 | * the License, or (at your option) any later version. | ||
10 | * | ||
11 | * Libgcrypt is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU Lesser General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU Lesser General Public | ||
17 | * License along with this program; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA | ||
19 | */ | ||
20 | |||
21 | #include <config.h> | ||
22 | #include <stdio.h> | ||
23 | #include <stdlib.h> | ||
24 | #include "mpi-internal.h" | ||
25 | |||
26 | /**************** | ||
27 | * Find the greatest common divisor G of A and B. | ||
28 | * Return: true if this 1, false in all other cases | ||
29 | */ | ||
30 | int | ||
31 | gcry_mpi_gcd( gcry_mpi_t g, gcry_mpi_t xa, gcry_mpi_t xb ) | ||
32 | { | ||
33 | gcry_mpi_t a, b; | ||
34 | |||
35 | a = mpi_copy(xa); | ||
36 | b = mpi_copy(xb); | ||
37 | |||
38 | /* TAOCP Vol II, 4.5.2, Algorithm A */ | ||
39 | a->sign = 0; | ||
40 | b->sign = 0; | ||
41 | while( gcry_mpi_cmp_ui( b, 0 ) ) { | ||
42 | _gcry_mpi_fdiv_r( g, a, b ); /* g used as temorary variable */ | ||
43 | mpi_set(a,b); | ||
44 | mpi_set(b,g); | ||
45 | } | ||
46 | mpi_set(g, a); | ||
47 | |||
48 | mpi_free(a); | ||
49 | mpi_free(b); | ||
50 | return !gcry_mpi_cmp_ui( g, 1); | ||
51 | } | ||
52 | |||
53 | |||
54 | |||