1 files changed, 54 insertions, 0 deletions
diff --git a/include/crypto/internal/drbg.h b/include/crypto/internal/drbg.h
new file mode 100644
index 000000000000..371e52dcee6c
--- /dev/null
+++ b/include/crypto/internal/drbg.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * NIST SP800-90A DRBG derivation function
+ *
+ * Copyright (C) 2014, Stephan Mueller <smueller@chronox.de>
+ */
+
+#ifndef _INTERNAL_DRBG_H
+#define _INTERNAL_DRBG_H
+
+/*
+ * Convert an integer into a byte representation of this integer.
+ * The byte representation is big-endian
+ *
+ * @val value to be converted
+ * @buf buffer holding the converted integer -- caller must ensure that
+ *      buffer size is at least 32 bit
+ */
+static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf)
+{
+	struct s {
+		__be32 conv;
+	};
+	struct s *conversion = (struct s *)buf;
+
+	conversion->conv = cpu_to_be32(val);
+}
+
+/*
+ * Concatenation Helper and string operation helper
+ *
+ * SP800-90A requires the concatenation of different data. To avoid copying
+ * buffers around or allocate additional memory, the following data structure
+ * is used to point to the original memory with its size. In addition, it
+ * is used to build a linked list. The linked list defines the concatenation
+ * of individual buffers. The order of memory block referenced in that
+ * linked list determines the order of concatenation.
+ */
+struct drbg_string {
+	const unsigned char *buf;
+	size_t len;
+	struct list_head list;
+};
+
+static inline void drbg_string_fill(struct drbg_string *string,
+				    const unsigned char *buf, size_t len)
+{
+	string->buf = buf;
+	string->len = len;
+	INIT_LIST_HEAD(&string->list);
+}
+
+#endif //_INTERNAL_DRBG_H