Initial code.

src/lib/crypto/crypto_aesctr.h

+/*-
+ * Copyright 2009 Colin Percival
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file was originally written by Colin Percival as part of the Tarsnap
+ * online backup system.
+ */
+#ifndef _CRYPTO_AESCTR_H_
+#define _CRYPTO_AESCTR_H_
+
+#include <stdint.h>
+
+#include <openssl/aes.h>
+
+/**
+ * crypto_aesctr_init(key, nonce):
+ * Prepare to encrypt/decrypt data with AES in CTR mode, using the provided
+ * expanded key and nonce.  The key provided must remain valid for the
+ * lifetime of the stream.
+ */
+struct crypto_aesctr * crypto_aesctr_init(AES_KEY *, uint64_t);
+
+/**
+ * crypto_aesctr_stream(stream, inbuf, outbuf, buflen):
+ * Generate the next ${buflen} bytes of the AES-CTR stream and xor them with
+ * bytes from ${inbuf}, writing the result into ${outbuf}.  If the buffers
+ * ${inbuf} and ${outbuf} overlap, they must be identical.
+ */
+void crypto_aesctr_stream(struct crypto_aesctr *, const uint8_t *,
+    uint8_t *, size_t);
+
+/**
+ * crypto_aesctr_free(stream):
+ * Free the provided stream object.
+ */
+void crypto_aesctr_free(struct crypto_aesctr *);
+
+#endif /* !_CRYPTO_AESCTR_H_ */