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authorLinus Torvalds <torvalds@linux-foundation.org>2023-08-29 11:23:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-29 11:23:29 -0700
commit68cf01760bc0891074e813b9bb06d2696cac1c01 (patch)
tree0bfbd6a995c19df689476782450a7df8bd51b213 /lib/crypto/mpi/mpi-sub-ui.c
parentf97e18a3f2fb78a4ed0d25e427535d9f853b9e9e (diff)
parent85b9bf9a514d991fcecb118d0a8a35e754ff9265 (diff)
Merge tag 'v6.6-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu: "API: - Move crypto engine callback from tfm ctx into algorithm object - Fix atomic sleep bug in crypto_destroy_instance - Move lib/mpi into lib/crypto Algorithms: - Add chacha20 and poly1305 implementation for powerpc p10 Drivers: - Add AES skcipher and aead support to starfive - Add Dynamic Boost Control support to ccp - Add support for STM32P13 platform to stm32" * tag 'v6.6-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (149 commits) Revert "dt-bindings: crypto: qcom,prng: Add SM8450" crypto: chelsio - Remove unused declarations X.509: if signature is unsupported skip validation crypto: qat - fix crypto capability detection for 4xxx crypto: drivers - Explicitly include correct DT includes crypto: engine - Remove crypto_engine_ctx crypto: zynqmp - Use new crypto_engine_op interface crypto: virtio - Use new crypto_engine_op interface crypto: stm32 - Use new crypto_engine_op interface crypto: jh7110 - Use new crypto_engine_op interface crypto: rk3288 - Use new crypto_engine_op interface crypto: omap - Use new crypto_engine_op interface crypto: keembay - Use new crypto_engine_op interface crypto: sl3516 - Use new crypto_engine_op interface crypto: caam - Use new crypto_engine_op interface crypto: aspeed - Remove non-standard sha512 algorithms crypto: aspeed - Use new crypto_engine_op interface crypto: amlogic - Use new crypto_engine_op interface crypto: sun8i-ss - Use new crypto_engine_op interface crypto: sun8i-ce - Use new crypto_engine_op interface ...
Diffstat (limited to 'lib/crypto/mpi/mpi-sub-ui.c')
-rw-r--r--lib/crypto/mpi/mpi-sub-ui.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/lib/crypto/mpi/mpi-sub-ui.c b/lib/crypto/mpi/mpi-sub-ui.c
new file mode 100644
index 000000000000..b41b082b5f3e
--- /dev/null
+++ b/lib/crypto/mpi/mpi-sub-ui.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* mpi-sub-ui.c - Subtract an unsigned integer from an MPI.
+ *
+ * Copyright 1991, 1993, 1994, 1996, 1999-2002, 2004, 2012, 2013, 2015
+ * Free Software Foundation, Inc.
+ *
+ * This file was based on the GNU MP Library source file:
+ * https://gmplib.org/repo/gmp-6.2/file/510b83519d1c/mpz/aors_ui.h
+ *
+ * The GNU MP Library is free software; you can redistribute it and/or modify
+ * it under the terms of either:
+ *
+ * * the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * or
+ *
+ * * 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.
+ *
+ * or both in parallel, as here.
+ *
+ * The GNU MP Library 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 copies of the GNU General Public License and the
+ * GNU Lesser General Public License along with the GNU MP Library. If not,
+ * see https://www.gnu.org/licenses/.
+ */
+
+#include "mpi-internal.h"
+
+int mpi_sub_ui(MPI w, MPI u, unsigned long vval)
+{
+ if (u->nlimbs == 0) {
+ if (mpi_resize(w, 1) < 0)
+ return -ENOMEM;
+ w->d[0] = vval;
+ w->nlimbs = (vval != 0);
+ w->sign = (vval != 0);
+ return 0;
+ }
+
+ /* If not space for W (and possible carry), increase space. */
+ if (mpi_resize(w, u->nlimbs + 1))
+ return -ENOMEM;
+
+ if (u->sign) {
+ mpi_limb_t cy;
+
+ cy = mpihelp_add_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval);
+ w->d[u->nlimbs] = cy;
+ w->nlimbs = u->nlimbs + cy;
+ w->sign = 1;
+ } else {
+ /* The signs are different. Need exact comparison to determine
+ * which operand to subtract from which.
+ */
+ if (u->nlimbs == 1 && u->d[0] < vval) {
+ w->d[0] = vval - u->d[0];
+ w->nlimbs = 1;
+ w->sign = 1;
+ } else {
+ mpihelp_sub_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval);
+ /* Size can decrease with at most one limb. */
+ w->nlimbs = (u->nlimbs - (w->d[u->nlimbs - 1] == 0));
+ w->sign = 0;
+ }
+ }
+
+ mpi_normalize(w);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mpi_sub_ui);