ChaCha20-Poly1305 support.
diff --git a/crypto/poly1305/poly1305.h b/crypto/poly1305/poly1305.h
new file mode 100644
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--- /dev/null
+++ b/crypto/poly1305/poly1305.h
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+/* Copyright (c) 2014, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#ifndef OPENSSL_HEADER_POLY1305_H
+#define OPENSSL_HEADER_POLY1305_H
+
+#include <openssl/base.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+typedef unsigned char poly1305_state[512];
+
+/* poly1305_init sets up |state| so that it can be used to calculate an
+ * authentication tag with the one-time key |key|. Note that |key| is a
+ * one-time key and therefore there is no `reset' method because that would
+ * enable several messages to be authenticated with the same key. */
+extern void CRYPTO_poly1305_init(poly1305_state* state, const uint8_t key[32]);
+
+/* poly1305_update processes |in_len| bytes from |in|. It can be called zero or
+ * more times after poly1305_init. */
+extern void CRYPTO_poly1305_update(poly1305_state* state, const uint8_t* in,
+ size_t in_len);
+
+/* poly1305_finish completes the poly1305 calculation and writes a 16 byte
+ * authentication tag to |mac|. */
+extern void CRYPTO_poly1305_finish(poly1305_state* state, uint8_t mac[16]);
+
+
+#if defined(__cplusplus)
+} /* extern C */
+#endif
+
+#endif /* OPENSSL_HEADER_POLY1305_H */
