chapoly: Provide a generic ChaCha20/Poly1305 AEAD supporting driver backends

2015-06-29 17:32:14 +02:00
parent 82f7f5882f
commit 370fb3feb0
9 changed files with 683 additions and 0 deletions
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2015 Martin Willi
+ * Copyright (C) 2015 revosec AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup chapoly_drv chapoly_drv
+ * @{ @ingroup chapoly
+ */
+
+#ifndef CHAPOLY_DRV_H_
+#define CHAPOLY_DRV_H_
+
+#include <library.h>
+
+#define CHACHA_BLOCK_SIZE 64
+#define CHACHA_IV_SIZE 8
+#define CHACHA_SALT_SIZE 4
+#define CHACHA_KEY_SIZE 32
+#define POLY_BLOCK_SIZE 16
+#define POLY_ICV_SIZE 16
+
+typedef struct chapoly_drv_t chapoly_drv_t;
+
+/**
+ * ChaCha20/Poly1305 backend implementation.
+ */
+struct chapoly_drv_t {
+
+	/**
+	 * Set the ChaCha20 encryption key.
+	 *
+	 * @param constant		16 byte key constant to use
+	 * @param key			32 byte encryption key
+	 * @param salt			4 byte nonce salt
+	 * @return				TRUE if key set
+	 */
+	bool (*set_key)(chapoly_drv_t *this, u_char *constant, u_char *key,
+					u_char *salt);
+
+	/**
+	 * Start an AEAD en/decryption session, reset state.
+	 *
+	 * @param iv			8 byte initialization vector for nonce
+	 * @return				TRUE if initialized
+	 */
+	bool (*init)(chapoly_drv_t *this, u_char *iv);
+
+	/**
+	 * Poly1305 update multiple blocks.
+	 *
+	 * @param data			data to update Poly1305 for
+	 * @param blocks		number of 16-byte blocks to process
+	 * @return				TRUE if updated
+	 */
+	bool (*poly)(chapoly_drv_t *this, u_char *data, u_int blocks);
+
+	/**
+	 * Create a single ChaCha20 keystream block.
+	 *
+	 * @param stream		64-byte block to write key stream data to
+	 * @return				TRUE if keystream returned
+	 */
+	bool (*chacha)(chapoly_drv_t *this, u_char *stream);
+
+	/**
+	 * Encrypt multiple blocks of data inline, update Poly1305.
+	 *
+	 * @param data			data to process
+	 * @param blocks		number of 64-byte blocks to process
+	 * @return				TRUE if encrypted
+	 */
+	bool (*encrypt)(chapoly_drv_t *this, u_char *data, u_int blocks);
+
+	/**
+	 * Decrypt multiple blocks of data inline, update Poly1305.
+	 *
+	 * @param data			data to process
+	 * @param blocks		number of 64-byte blocks to process
+	 * @return				TRUE if decrypted
+	 */
+	bool (*decrypt)(chapoly_drv_t *this, u_char *data, u_int blocks);
+
+	/**
+	 * End a AEAD encryption session, return MAC.
+	 *
+	 * @param mac			16-byte block to write MAC to
+	 * @return				TRUE if MAC returned
+	 */
+	bool (*finish)(chapoly_drv_t *this, u_char *mac);
+
+	/**
+	 * Destroy a chapoly_drv_t.
+	 */
+	void (*destroy)(chapoly_drv_t *this);
+};
+
+/**
+ * Create a chapoly_drv instance.
+ */
+chapoly_drv_t *chapoly_drv_probe();
+
+#endif /** CHAPOLY_DRV_H_ @}*/