1 files changed, 83 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/module/icp/algs/modes/gcm_generic.c b/sys/contrib/openzfs/module/icp/algs/modes/gcm_generic.c
new file mode 100644
index 000000000000..16b57998a92f
--- /dev/null
+++ b/sys/contrib/openzfs/module/icp/algs/modes/gcm_generic.c
@@ -0,0 +1,83 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#include <modes/gcm_impl.h>
+
+struct aes_block {
+	uint64_t a;
+	uint64_t b;
+};
+
+/*
+ * Perform a carry-less multiplication (that is, use XOR instead of the
+ * multiply operator) on *x_in and *y and place the result in *res.
+ *
+ * Byte swap the input (*x_in and *y) and the output (*res).
+ *
+ * Note: x_in, y, and res all point to 16-byte numbers (an array of two
+ * 64-bit integers).
+ */
+static void
+gcm_generic_mul(uint64_t *x_in, uint64_t *y, uint64_t *res)
+{
+	static const uint64_t R = 0xe100000000000000ULL;
+	struct aes_block z = {0, 0};
+	struct aes_block v;
+	uint64_t x;
+	int i, j;
+
+	v.a = ntohll(y[0]);
+	v.b = ntohll(y[1]);
+
+	for (j = 0; j < 2; j++) {
+		x = ntohll(x_in[j]);
+		for (i = 0; i < 64; i++, x <<= 1) {
+			if (x & 0x8000000000000000ULL) {
+				z.a ^= v.a;
+				z.b ^= v.b;
+			}
+			if (v.b & 1ULL) {
+				v.b = (v.a << 63)|(v.b >> 1);
+				v.a = (v.a >> 1) ^ R;
+			} else {
+				v.b = (v.a << 63)|(v.b >> 1);
+				v.a = v.a >> 1;
+			}
+		}
+	}
+	res[0] = htonll(z.a);
+	res[1] = htonll(z.b);
+}
+
+static boolean_t
+gcm_generic_will_work(void)
+{
+	return (B_TRUE);
+}
+
+const gcm_impl_ops_t gcm_generic_impl = {
+	.mul = &gcm_generic_mul,
+	.is_supported = &gcm_generic_will_work,
+	.name = "generic"
+};