1 files changed, 70 insertions, 0 deletions
diff --git a/src/crypto/include/zinc/chacha20.h b/src/crypto/include/zinc/chacha20.h
new file mode 100644
index 0000000..1b0083d
--- /dev/null
+++ b/src/crypto/include/zinc/chacha20.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#ifndef _ZINC_CHACHA20_H
+#define _ZINC_CHACHA20_H
+
+#include <asm/unaligned.h>
+#include <linux/simd.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+enum chacha20_lengths {
+	CHACHA20_NONCE_SIZE = 16,
+	CHACHA20_KEY_SIZE = 32,
+	CHACHA20_KEY_WORDS = CHACHA20_KEY_SIZE / sizeof(u32),
+	CHACHA20_BLOCK_SIZE = 64,
+	CHACHA20_BLOCK_WORDS = CHACHA20_BLOCK_SIZE / sizeof(u32),
+	HCHACHA20_NONCE_SIZE = CHACHA20_NONCE_SIZE,
+	HCHACHA20_KEY_SIZE = CHACHA20_KEY_SIZE
+};
+
+enum chacha20_constants { /* expand 32-byte k */
+	CHACHA20_CONSTANT_EXPA = 0x61707865U,
+	CHACHA20_CONSTANT_ND_3 = 0x3320646eU,
+	CHACHA20_CONSTANT_2_BY = 0x79622d32U,
+	CHACHA20_CONSTANT_TE_K = 0x6b206574U
+};
+
+struct chacha20_ctx {
+	union {
+		u32 state[16];
+		struct {
+			u32 constant[4];
+			u32 key[8];
+			u32 counter[4];
+		};
+	};
+};
+
+static inline void chacha20_init(struct chacha20_ctx *ctx,
+				 const u8 key[CHACHA20_KEY_SIZE],
+				 const u64 nonce)
+{
+	ctx->constant[0] = CHACHA20_CONSTANT_EXPA;
+	ctx->constant[1] = CHACHA20_CONSTANT_ND_3;
+	ctx->constant[2] = CHACHA20_CONSTANT_2_BY;
+	ctx->constant[3] = CHACHA20_CONSTANT_TE_K;
+	ctx->key[0] = get_unaligned_le32(key + 0);
+	ctx->key[1] = get_unaligned_le32(key + 4);
+	ctx->key[2] = get_unaligned_le32(key + 8);
+	ctx->key[3] = get_unaligned_le32(key + 12);
+	ctx->key[4] = get_unaligned_le32(key + 16);
+	ctx->key[5] = get_unaligned_le32(key + 20);
+	ctx->key[6] = get_unaligned_le32(key + 24);
+	ctx->key[7] = get_unaligned_le32(key + 28);
+	ctx->counter[0] = 0;
+	ctx->counter[1] = 0;
+	ctx->counter[2] = nonce & U32_MAX;
+	ctx->counter[3] = nonce >> 32;
+}
+void chacha20(struct chacha20_ctx *ctx, u8 *dst, const u8 *src, u32 len,
+	      simd_context_t *simd_context);
+
+void hchacha20(u32 derived_key[CHACHA20_KEY_WORDS],
+	       const u8 nonce[HCHACHA20_NONCE_SIZE],
+	       const u8 key[HCHACHA20_KEY_SIZE], simd_context_t *simd_context);
+
+#endif /* _ZINC_CHACHA20_H */