1 files changed, 42 insertions, 0 deletions
diff --git a/include/crypto/chacha20.h b/include/crypto/chacha20.h
new file mode 100644
index 000000000..3dd5ab189
--- /dev/null
+++ b/include/crypto/chacha20.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common values for the ChaCha20 algorithm
+ */
+
+#ifndef _CRYPTO_CHACHA20_H
+#define _CRYPTO_CHACHA20_H
+
+#include <crypto/skcipher.h>
+#include <linux/types.h>
+#include <linux/crypto.h>
+
+#define CHACHA20_IV_SIZE	16
+#define CHACHA20_KEY_SIZE	32
+#define CHACHA20_BLOCK_SIZE	64
+
+struct chacha20_ctx {
+	u32 key[8];
+};
+
+void chacha20_block(u32 *state, u8 *stream);
+void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv);
+int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
+			   unsigned int keysize);
+int crypto_chacha20_crypt(struct skcipher_request *req);
+
+enum chacha_constants { /* expand 32-byte k */
+	CHACHA_CONSTANT_EXPA = 0x61707865U,
+	CHACHA_CONSTANT_ND_3 = 0x3320646eU,
+	CHACHA_CONSTANT_2_BY = 0x79622d32U,
+	CHACHA_CONSTANT_TE_K = 0x6b206574U
+};
+
+static inline void chacha_init_consts(u32 *state)
+{
+	state[0]  = CHACHA_CONSTANT_EXPA;
+	state[1]  = CHACHA_CONSTANT_ND_3;
+	state[2]  = CHACHA_CONSTANT_2_BY;
+	state[3]  = CHACHA_CONSTANT_TE_K;
+}
+
+#endif