Merge tag '5.15-rc-cifs-part2' of git://git.samba.org/sfrench/cifs-2.6

[linux-2.6-microblaze.git] / fs / smbfs_common / cifs_arc4.c

diff --git a/fs/smbfs_common/cifs_arc4.c b/fs/smbfs_common/cifs_arc4.c
new file mode 100644 (file)
index 0000000..85ba15a
--- /dev/null
+++ b/fs/smbfs_common/cifs_arc4.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Cryptographic API
+ *
+ * ARC4 Cipher Algorithm
+ *
+ * Jon Oberheide <jon@oberheide.org>
+ */
+
+#include <linux/module.h>
+#include "arc4.h"
+
+MODULE_LICENSE("GPL");
+
+int cifs_arc4_setkey(struct arc4_ctx *ctx, const u8 *in_key, unsigned int key_len)
+{
+       int i, j = 0, k = 0;
+
+       ctx->x = 1;
+       ctx->y = 0;
+
+       for (i = 0; i < 256; i++)
+               ctx->S[i] = i;
+
+       for (i = 0; i < 256; i++) {
+               u32 a = ctx->S[i];
+
+               j = (j + in_key[k] + a) & 0xff;
+               ctx->S[i] = ctx->S[j];
+               ctx->S[j] = a;
+               if (++k >= key_len)
+                       k = 0;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(cifs_arc4_setkey);
+
+void cifs_arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in, unsigned int len)
+{
+       u32 *const S = ctx->S;
+       u32 x, y, a, b;
+       u32 ty, ta, tb;
+
+       if (len == 0)
+               return;
+
+       x = ctx->x;
+       y = ctx->y;
+
+       a = S[x];
+       y = (y + a) & 0xff;
+       b = S[y];
+
+       do {
+               S[y] = a;
+               a = (a + b) & 0xff;
+               S[x] = b;
+               x = (x + 1) & 0xff;
+               ta = S[x];
+               ty = (y + ta) & 0xff;
+               tb = S[ty];
+               *out++ = *in++ ^ S[a];
+               if (--len == 0)
+                       break;
+               y = ty;
+               a = ta;
+               b = tb;
+       } while (true);
+
+       ctx->x = x;
+       ctx->y = y;
+}
+EXPORT_SYMBOL_GPL(cifs_arc4_crypt);
+
+static int __init
+init_smbfs_common(void)
+{
+       return 0;
+}
+static void __init
+exit_smbfs_common(void)
+{
+}
+
+module_init(init_smbfs_common)
+module_exit(exit_smbfs_common)