Update the built-in Chacha20-Poly1305 code to an RFC 7539 complaint version.

[tinc] / src / chacha-poly1305 / chachapoly.h

diff --git a/src/chacha-poly1305/chachapoly.h b/src/chacha-poly1305/chachapoly.h
new file mode 100644 (file)
index 0000000..ffc9576
--- /dev/null
+++ b/src/chacha-poly1305/chachapoly.h
@@ -0,0 +1,82 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Grigori Goronzy <goronzy@kinoho.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef CHACHAPOLY_H
+#define CHACHAPOLY_H
+
+#include "chacha.h"
+#include "poly1305.h"
+
+#define CHACHAPOLY_OK           0
+#define CHACHAPOLY_INVALID_MAC  -1
+
+struct chachapoly_ctx {
+       struct chacha_ctx cha_ctx;
+};
+
+/**
+ * Initialize ChaCha20-Poly1305 AEAD.
+ * For RFC 7539 conformant AEAD, 256 bit keys must be used.
+ *
+ * \param ctx context data
+ * \param key 16 or 32 bytes of key material
+ * \param key_len key length, 256 or 512 bits
+ * \return success if 0
+ */
+int chachapoly_init(struct chachapoly_ctx *ctx, const void *key, int key_len);
+
+/**
+ * Encrypt or decrypt with ChaCha20-Poly1305. The AEAD construction conforms
+ * to RFC 7539.
+ *
+ * \param ctx context data
+ * \param nonce nonce (12 bytes)
+ * \param ad associated data
+ * \param ad_len associated data length in bytes
+ * \param input plaintext/ciphertext input
+ * \param input_len input length in bytes;
+ * \param output plaintext/ciphertext output
+ * \param tag tag output
+ * \param tag_len tag length in bytes (0-16);
+          if 0, authentification is skipped
+ * \param encrypt decrypt if 0, else encrypt
+ * \return CHACHAPOLY_OK if no error, CHACHAPOLY_INVALID_MAC if auth
+ *         failed when decrypting
+ */
+int chachapoly_crypt(struct chachapoly_ctx *ctx, const void *nonce,
+                     const void *ad, int ad_len, void *input, int input_len,
+                     void *output, void *tag, int tag_len, int encrypt);
+
+/**
+ * Encrypt or decrypt with Chacha20-Poly1305 for short messages.
+ * The AEAD construction is different from chachapoly_crypt, but more
+ * efficient for small messages. Up to 32 bytes can be encrypted. The size
+ * of associated data is not restricted. The interface is similar to
+ * chachapoly_crypt.
+ */
+int chachapoly_crypt_short(struct chachapoly_ctx *ctx, const void *nonce,
+                           const void *ad, int ad_len, void *input, int input_len,
+                           void *output, void *tag, int tag_len, int encrypt);
+
+#endif