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authorThomas Zimmermann <[email protected]>2023-10-11 09:50:59 +0200
committerThomas Zimmermann <[email protected]>2023-10-11 09:50:59 +0200
commit57390019b68b83f96eb98f490367b9df1f2d77cb (patch)
treee6d4b6c75efdd2d7fb7d37f980688c491be3ff6a /lib/crypto/mpi/mpih-cmp.c
parente5f9d543419c78ac58f3b3557bc5a76b20ff600b (diff)
parent389af786f92ecdff35883551d54bf4e507ffcccb (diff)
Merge drm/drm-next into drm-misc-next
Updating drm-misc-next to the state of Linux v6.6-rc2. Signed-off-by: Thomas Zimmermann <[email protected]>
Diffstat (limited to 'lib/crypto/mpi/mpih-cmp.c')
-rw-r--r--lib/crypto/mpi/mpih-cmp.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/lib/crypto/mpi/mpih-cmp.c b/lib/crypto/mpi/mpih-cmp.c
new file mode 100644
index 000000000000..f23709114a65
--- /dev/null
+++ b/lib/crypto/mpi/mpih-cmp.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* mpihelp-sub.c - MPI helper functions
+ * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
+ * Copyright (C) 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"
+
+/****************
+ * Compare OP1_PTR/OP1_SIZE with OP2_PTR/OP2_SIZE.
+ * There are no restrictions on the relative sizes of
+ * the two arguments.
+ * Return 1 if OP1 > OP2, 0 if they are equal, and -1 if OP1 < OP2.
+ */
+int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size)
+{
+ mpi_size_t i;
+ mpi_limb_t op1_word, op2_word;
+
+ for (i = size - 1; i >= 0; i--) {
+ op1_word = op1_ptr[i];
+ op2_word = op2_ptr[i];
+ if (op1_word != op2_word)
+ goto diff;
+ }
+ return 0;
+
+diff:
+ /* This can *not* be simplified to
+ * op2_word - op2_word
+ * since that expression might give signed overflow. */
+ return (op1_word > op2_word) ? 1 : -1;
+}