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authorJohannes Berg <johannes.berg@intel.com>2023-10-05 22:57:34 +0200
committerKalle Valo <kvalo@kernel.org>2023-10-06 17:08:47 +0300
commit7d6904bf26b96ef087514cb7a8c50b62a4911c99 (patch)
tree2feaff8495d88c2102dc2e017b7afc5c58db02d6 /lib/crypto/mpi/generic_mpih-rshift.c
parent9418edf8ff01e7a4904aac1aca4864ecdea37593 (diff)
parent22061bfc57fe08c77141dc876b4af75603c4d61d (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.c50
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
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index 0000000000000..e07bc69aa8988
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+++ b/lib/crypto/mpi/generic_mpih-rshift.c
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+// 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;
+}