chore: checkpoint before Python removal

vendor/aws-lc-sys/aws-lc/include/openssl/chacha.h

@@ -0,0 +1,37 @@
+// Copyright (c) 2014, Google Inc.
+// SPDX-License-Identifier: ISC
+
+#ifndef OPENSSL_HEADER_CHACHA_H
+#define OPENSSL_HEADER_CHACHA_H
+
+#include <openssl/base.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+// ChaCha20.
+//
+// ChaCha20 is a stream cipher. See https://tools.ietf.org/html/rfc8439.
+
+
+// CRYPTO_chacha_20 encrypts |in_len| bytes from |in| with the given key and
+// nonce and writes the result to |out|. If |in| and |out| alias, they must be
+// equal. The initial block counter is specified by |counter|. |in| must be
+// aligned on a block boundary.
+//
+// This function implements a 32-bit block counter as in RFC 8439. On overflow,
+// the counter wraps. Reusing a key, nonce, and block counter combination is not
+// secure, so wrapping is usually a bug in the caller. While it is possible to
+// wrap without reuse with a large initial block counter, this is not
+// recommended and may not be portable to other ChaCha20 implementations.
+OPENSSL_EXPORT void CRYPTO_chacha_20(uint8_t *out, const uint8_t *in,
+                                     size_t in_len, const uint8_t key[32],
+                                     const uint8_t nonce[12], uint32_t counter);
+
+
+#if defined(__cplusplus)
+}  // extern C
+#endif
+
+#endif  // OPENSSL_HEADER_CHACHA_H