Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/lib/crypto/chacha.c b/lib/crypto/chacha.c
new file mode 100644
index 0000000..4ccbec4
--- /dev/null
+++ b/lib/crypto/chacha.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * The "hash function" used as the core of the ChaCha stream cipher (RFC7539)
+ *
+ * Copyright (C) 2015 Martin Willi
+ */
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/bitops.h>
+#include <linux/string.h>
+#include <asm/unaligned.h>
+#include <crypto/chacha.h>
+
+static void chacha_permute(u32 *x, int nrounds)
+{
+ int i;
+
+ /* whitelist the allowed round counts */
+ WARN_ON_ONCE(nrounds != 20 && nrounds != 12);
+
+ for (i = 0; i < nrounds; i += 2) {
+ x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 16);
+ x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 16);
+ x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 16);
+ x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 16);
+
+ x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 12);
+ x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 12);
+ x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 12);
+ x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 12);
+
+ x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 8);
+ x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 8);
+ x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 8);
+ x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 8);
+
+ x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 7);
+ x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 7);
+ x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 7);
+ x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 7);
+
+ x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 16);
+ x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 16);
+ x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 16);
+ x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 16);
+
+ x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 12);
+ x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 12);
+ x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 12);
+ x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 12);
+
+ x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 8);
+ x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 8);
+ x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 8);
+ x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 8);
+
+ x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 7);
+ x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 7);
+ x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 7);
+ x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 7);
+ }
+}
+
+/**
+ * chacha_block - generate one keystream block and increment block counter
+ * @state: input state matrix (16 32-bit words)
+ * @stream: output keystream block (64 bytes)
+ * @nrounds: number of rounds (20 or 12; 20 is recommended)
+ *
+ * This is the ChaCha core, a function from 64-byte strings to 64-byte strings.
+ * The caller has already converted the endianness of the input. This function
+ * also handles incrementing the block counter in the input matrix.
+ */
+void chacha_block_generic(u32 *state, u8 *stream, int nrounds)
+{
+ u32 x[16];
+ int i;
+
+ memcpy(x, state, 64);
+
+ chacha_permute(x, nrounds);
+
+ for (i = 0; i < ARRAY_SIZE(x); i++)
+ put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]);
+
+ state[12]++;
+}
+EXPORT_SYMBOL(chacha_block_generic);
+
+/**
+ * hchacha_block_generic - abbreviated ChaCha core, for XChaCha
+ * @state: input state matrix (16 32-bit words)
+ * @out: output (8 32-bit words)
+ * @nrounds: number of rounds (20 or 12; 20 is recommended)
+ *
+ * HChaCha is the ChaCha equivalent of HSalsa and is an intermediate step
+ * towards XChaCha (see https://cr.yp.to/snuffle/xsalsa-20081128.pdf). HChaCha
+ * skips the final addition of the initial state, and outputs only certain words
+ * of the state. It should not be used for streaming directly.
+ */
+void hchacha_block_generic(const u32 *state, u32 *stream, int nrounds)
+{
+ u32 x[16];
+
+ memcpy(x, state, 64);
+
+ chacha_permute(x, nrounds);
+
+ memcpy(&stream[0], &x[0], 16);
+ memcpy(&stream[4], &x[12], 16);
+}
+EXPORT_SYMBOL(hchacha_block_generic);