diff options
author | Johannes Berg <johannes.berg@intel.com> | 2023-10-05 22:57:34 +0200 |
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committer | Kalle Valo <kvalo@kernel.org> | 2023-10-06 17:08:47 +0300 |
commit | 7d6904bf26b96ef087514cb7a8c50b62a4911c99 (patch) | |
tree | 2feaff8495d88c2102dc2e017b7afc5c58db02d6 /lib/crypto/mpi/generic_mpih-rshift.c | |
parent | 9418edf8ff01e7a4904aac1aca4864ecdea37593 (diff) | |
parent | 22061bfc57fe08c77141dc876b4af75603c4d61d (diff) |
Merge wireless into wireless-next
Resolve several conflicts, mostly between changes/fixes in
wireless and the locking rework in wireless-next. One of
the conflicts actually shows a bug in wireless that we'll
want to fix separately.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Diffstat (limited to 'lib/crypto/mpi/generic_mpih-rshift.c')
-rw-r--r-- | lib/crypto/mpi/generic_mpih-rshift.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/lib/crypto/mpi/generic_mpih-rshift.c b/lib/crypto/mpi/generic_mpih-rshift.c new file mode 100644 index 0000000000000..e07bc69aa8988 --- /dev/null +++ b/lib/crypto/mpi/generic_mpih-rshift.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* mpih-rshift.c - MPI helper functions + * Copyright (C) 1994, 1996, 1998, 1999, + * 2000, 2001 Free Software Foundation, Inc. + * + * This file is part of GNUPG + * + * Note: This code is heavily based on the GNU MP Library. + * Actually it's the same code with only minor changes in the + * way the data is stored; this is to support the abstraction + * of an optional secure memory allocation which may be used + * to avoid revealing of sensitive data due to paging etc. + * The GNU MP Library itself is published under the LGPL; + * however I decided to publish this code under the plain GPL. + */ + +#include "mpi-internal.h" + +/* Shift U (pointed to by UP and USIZE limbs long) CNT bits to the right + * and store the USIZE least significant limbs of the result at WP. + * The bits shifted out to the right are returned. + * + * Argument constraints: + * 1. 0 < CNT < BITS_PER_MP_LIMB + * 2. If the result is to be written over the input, WP must be <= UP. + */ + +mpi_limb_t +mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned cnt) +{ + mpi_limb_t high_limb, low_limb; + unsigned sh_1, sh_2; + mpi_size_t i; + mpi_limb_t retval; + + sh_1 = cnt; + wp -= 1; + sh_2 = BITS_PER_MPI_LIMB - sh_1; + high_limb = up[0]; + retval = high_limb << sh_2; + low_limb = high_limb; + for (i = 1; i < usize; i++) { + high_limb = up[i]; + wp[i] = (low_limb >> sh_1) | (high_limb << sh_2); + low_limb = high_limb; + } + wp[i] = low_limb >> sh_1; + + return retval; +} |