diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-10 21:51:23 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-10 21:51:23 -0800 |
commit | e7691a1ce341c80ed9504244a36b31c025217391 (patch) | |
tree | e9941bb350f64a726130e299c411821da6f41a53 /lib/mpi/mpi-scan.c | |
parent | 5cd9599bba428762025db6027764f1c59d0b1e1b (diff) | |
parent | 8fcc99549522fc7a0bbaeb5755855ab0d9a59ce8 (diff) |
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-scan.c')
-rw-r--r-- | lib/mpi/mpi-scan.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/lib/mpi/mpi-scan.c b/lib/mpi/mpi-scan.c new file mode 100644 index 00000000000..b2da5ad9619 --- /dev/null +++ b/lib/mpi/mpi-scan.c @@ -0,0 +1,136 @@ +/* mpi-scan.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" +#include "longlong.h" + +/**************** + * Scan through an mpi and return byte for byte. a -1 is returned to indicate + * the end of the mpi. Scanning is done from the lsb to the msb, returned + * values are in the range of 0 .. 255. + * + * FIXME: This code is VERY ugly! + */ +int mpi_getbyte(const MPI a, unsigned idx) +{ + int i, j; + unsigned n; + mpi_ptr_t ap; + mpi_limb_t limb; + + ap = a->d; + for (n = 0, i = 0; i < a->nlimbs; i++) { + limb = ap[i]; + for (j = 0; j < BYTES_PER_MPI_LIMB; j++, n++) + if (n == idx) + return (limb >> j * 8) & 0xff; + } + return -1; +} + +/**************** + * Put a value at position IDX into A. idx counts from lsb to msb + */ +void mpi_putbyte(MPI a, unsigned idx, int xc) +{ + int i, j; + unsigned n; + mpi_ptr_t ap; + mpi_limb_t limb, c; + + c = xc & 0xff; + ap = a->d; + for (n = 0, i = 0; i < a->alloced; i++) { + limb = ap[i]; + for (j = 0; j < BYTES_PER_MPI_LIMB; j++, n++) + if (n == idx) { +#if BYTES_PER_MPI_LIMB == 4 + if (j == 0) + limb = (limb & 0xffffff00) | c; + else if (j == 1) + limb = (limb & 0xffff00ff) | (c << 8); + else if (j == 2) + limb = (limb & 0xff00ffff) | (c << 16); + else + limb = (limb & 0x00ffffff) | (c << 24); +#elif BYTES_PER_MPI_LIMB == 8 + if (j == 0) + limb = (limb & 0xffffffffffffff00) | c; + else if (j == 1) + limb = + (limb & 0xffffffffffff00ff) | (c << + 8); + else if (j == 2) + limb = + (limb & 0xffffffffff00ffff) | (c << + 16); + else if (j == 3) + limb = + (limb & 0xffffffff00ffffff) | (c << + 24); + else if (j == 4) + limb = + (limb & 0xffffff00ffffffff) | (c << + 32); + else if (j == 5) + limb = + (limb & 0xffff00ffffffffff) | (c << + 40); + else if (j == 6) + limb = + (limb & 0xff00ffffffffffff) | (c << + 48); + else + limb = + (limb & 0x00ffffffffffffff) | (c << + 56); +#else +#error please enhance this function, its ugly - i know. +#endif + if (a->nlimbs <= i) + a->nlimbs = i + 1; + ap[i] = limb; + return; + } + } + log_bug("index out of range\n"); +} + +/**************** + * Count the number of zerobits at the low end of A + */ +unsigned mpi_trailing_zeros(const MPI a) +{ + unsigned n, count = 0; + + for (n = 0; n < a->nlimbs; n++) { + if (a->d[n]) { + unsigned nn; + mpi_limb_t alimb = a->d[n]; + + count_trailing_zeros(nn, alimb); + count += nn; + break; + } + count += BITS_PER_MPI_LIMB; + } + return count; + +} |