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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-sub1.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-sub1.c')
-rw-r--r--lib/crypto/mpi/generic_mpih-sub1.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/lib/crypto/mpi/generic_mpih-sub1.c b/lib/crypto/mpi/generic_mpih-sub1.c
new file mode 100644
index 000000000000..eea4382aad5f
--- /dev/null
+++ b/lib/crypto/mpi/generic_mpih-sub1.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* mpihelp-add_2.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 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"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_ptr_t s2_ptr, mpi_size_t size)
+{
+ mpi_limb_t x, y, cy;
+ mpi_size_t j;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ the loop becomes faster. */
+ j = -size;
+
+ /* Offset the base pointers to compensate for the negative indices. */
+ s1_ptr -= j;
+ s2_ptr -= j;
+ res_ptr -= j;
+
+ cy = 0;
+ do {
+ y = s2_ptr[j];
+ x = s1_ptr[j];
+ y += cy; /* add previous carry to subtrahend */
+ cy = y < cy; /* get out carry from that addition */
+ y = x - y; /* main subtract */
+ cy += y > x; /* get out carry from the subtract, combine */
+ res_ptr[j] = y;
+ } while (++j);
+
+ return cy;
+}