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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-11 09:51:23 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-11 09:51:23 +0400 |
commit | e7691a1ce341c80ed9504244a36b31c025217391 (patch) | |
tree | e9941bb350f64a726130e299c411821da6f41a53 /lib/mpi/mpi-gcd.c | |
parent | 5cd9599bba428762025db6027764f1c59d0b1e1b (diff) | |
parent | 8fcc99549522fc7a0bbaeb5755855ab0d9a59ce8 (diff) | |
download | linux-e7691a1ce341c80ed9504244a36b31c025217391.tar.xz |
Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security
* 'for-linus' of git://selinuxproject.org/~jmorris/linux-security: (32 commits)
ima: fix invalid memory reference
ima: free duplicate measurement memory
security: update security_file_mmap() docs
selinux: Casting (void *) value returned by kmalloc is useless
apparmor: fix module parameter handling
Security: tomoyo: add .gitignore file
tomoyo: add missing rcu_dereference()
apparmor: add missing rcu_dereference()
evm: prevent racing during tfm allocation
evm: key must be set once during initialization
mpi/mpi-mpow: NULL dereference on allocation failure
digsig: build dependency fix
KEYS: Give key types their own lockdep class for key->sem
TPM: fix transmit_cmd error logic
TPM: NSC and TIS drivers X86 dependency fix
TPM: Export wait_for_stat for other vendor specific drivers
TPM: Use vendor specific function for status probe
tpm_tis: add delay after aborting command
tpm_tis: Check return code from getting timeouts/durations
tpm: Introduce function to poll for result of self test
...
Fix up trivial conflict in lib/Makefile due to addition of CONFIG_MPI
and SIGSIG next to CONFIG_DQL addition.
Diffstat (limited to 'lib/mpi/mpi-gcd.c')
-rw-r--r-- | lib/mpi/mpi-gcd.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/lib/mpi/mpi-gcd.c b/lib/mpi/mpi-gcd.c new file mode 100644 index 000000000000..13c48aef9c4e --- /dev/null +++ b/lib/mpi/mpi-gcd.c @@ -0,0 +1,59 @@ +/* mpi-gcd.c - MPI functions + * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG 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 2 of the License, or + * (at your option) any later version. + * + * GnuPG 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, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include "mpi-internal.h" + +/**************** + * Find the greatest common divisor G of A and B. + * Return: true if this 1, false in all other cases + */ +int mpi_gcd(MPI g, const MPI xa, const MPI xb) +{ + MPI a = NULL, b = NULL; + + if (mpi_copy(&a, xa) < 0) + goto nomem; + + if (mpi_copy(&b, xb) < 0) + goto nomem; + + /* TAOCP Vol II, 4.5.2, Algorithm A */ + a->sign = 0; + b->sign = 0; + while (mpi_cmp_ui(b, 0)) { + if (mpi_fdiv_r(g, a, b) < 0) /* g used as temorary variable */ + goto nomem; + if (mpi_set(a, b) < 0) + goto nomem; + if (mpi_set(b, g) < 0) + goto nomem; + } + if (mpi_set(g, a) < 0) + goto nomem; + + mpi_free(a); + mpi_free(b); + return !mpi_cmp_ui(g, 1); + +nomem: + mpi_free(a); + mpi_free(b); + return -ENOMEM; +} |