/*-
 * Copyright (c) 2009 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Alistair Crooks (agc@NetBSD.org)
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */
/*
 * Copyright (c) 2005-2008 Nominet UK (www.nic.uk)
 * All rights reserved.
 * Contributors: Ben Laurie, Rachel Willmer. The Contributors have asserted
 * their moral rights under the UK Copyright Design and Patents Act 1988 to
 * be recorded as the authors of this copyright work.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License.
 *
 * You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/** \file
 * Parser for OpenPGP packets - headers.
 */

#ifndef PACKET_PARSE_H_
#define PACKET_PARSE_H_

#include "types.h"
#include "packet.h"

/** pgp_region_t */
typedef struct pgp_region_t {
	struct pgp_region_t	*parent;
	unsigned		 length;
	unsigned		 readc;		/* length read */
	unsigned		 last_read;
		/* length of last read, only valid in deepest child */
	unsigned		 indeterminate:1;
} pgp_region_t;

void pgp_init_subregion(pgp_region_t *, pgp_region_t *);

/** pgp_cb_ret_t */
typedef enum {
	PGP_RELEASE_MEMORY,
	PGP_KEEP_MEMORY,
	PGP_FINISHED
} pgp_cb_ret_t;

typedef struct pgp_cbdata_t	 pgp_cbdata_t;

typedef pgp_cb_ret_t pgp_cbfunc_t(const pgp_packet_t *,
					pgp_cbdata_t *);

pgp_cb_ret_t
get_passphrase_cb(const pgp_packet_t *, pgp_cbdata_t *);

typedef struct pgp_stream_t	pgp_stream_t;
typedef struct pgp_reader_t		pgp_reader_t;
typedef struct pgp_cryptinfo_t	pgp_cryptinfo_t;

/*
   A reader MUST read at least one byte if it can, and should read up
   to the number asked for. Whether it reads more for efficiency is
   its own decision, but if it is a stacked reader it should never
   read more than the length of the region it operates in (which it
   would have to be given when it is stacked).

   If a read is short because of EOF, then it should return the short
   read (obviously this will be zero on the second attempt, if not the
   first). Because a reader is not obliged to do a full read, only a
   zero return can be taken as an indication of EOF.

   If there is an error, then the callback should be notified, the
   error stacked, and -1 should be returned.

   Note that although length is a size_t, a reader will never be asked
   to read more than INT_MAX in one go.

 */
typedef int pgp_reader_func_t(pgp_stream_t *, void *, size_t, pgp_error_t **,
				pgp_reader_t *, pgp_cbdata_t *);

typedef void pgp_reader_destroyer_t(pgp_reader_t *);

void pgp_stream_delete(pgp_stream_t *);
pgp_error_t *pgp_stream_get_errors(pgp_stream_t *);
pgp_crypt_t *pgp_get_decrypt(pgp_stream_t *);

void pgp_set_callback(pgp_stream_t *, pgp_cbfunc_t *, void *);
void pgp_callback_push(pgp_stream_t *, pgp_cbfunc_t *, void *);
void *pgp_callback_arg(pgp_cbdata_t *);
void *pgp_callback_errors(pgp_cbdata_t *);
void pgp_reader_set(pgp_stream_t *, pgp_reader_func_t *,
			pgp_reader_destroyer_t *, void *);
void pgp_reader_push(pgp_stream_t *, pgp_reader_func_t *,
			pgp_reader_destroyer_t *, void *);
void pgp_reader_pop(pgp_stream_t *);

void *pgp_reader_get_arg(pgp_reader_t *);

pgp_cb_ret_t pgp_callback(const pgp_packet_t *,
					pgp_cbdata_t *);
pgp_cb_ret_t pgp_stacked_callback(const pgp_packet_t *,
					pgp_cbdata_t *);
pgp_reader_t *pgp_readinfo(pgp_stream_t *);

int pgp_parse(pgp_stream_t *, const int);

/** Used to specify whether subpackets should be returned raw, parsed
* or ignored.  */
typedef enum {
	PGP_PARSE_RAW,		/* Callback Raw */
	PGP_PARSE_PARSED,	/* Callback Parsed */
	PGP_PARSE_IGNORE	/* Don't callback */
} pgp_parse_type_t;

void pgp_parse_options(pgp_stream_t *, pgp_content_enum,
			pgp_parse_type_t);

unsigned pgp_limited_read(pgp_stream_t *, uint8_t *, size_t, pgp_region_t *,
			pgp_error_t **, pgp_reader_t *,
			pgp_cbdata_t *);
unsigned pgp_stacked_limited_read(pgp_stream_t *, uint8_t *, unsigned,
			pgp_region_t *, pgp_error_t **,
			pgp_reader_t *, pgp_cbdata_t *);
void pgp_parse_hash_init(pgp_stream_t *, pgp_hash_alg_t,
			const uint8_t *);
void pgp_parse_hash_data(pgp_stream_t *, const void *, size_t);
void pgp_parse_hash_finish(pgp_stream_t *);
pgp_hash_t *pgp_parse_hash_find(pgp_stream_t *, const uint8_t *);

pgp_reader_func_t    pgp_stacked_read;

int pgp_decompress(pgp_region_t *, pgp_stream_t *,
			pgp_compression_type_t);
unsigned pgp_writez(pgp_output_t *, const uint8_t *,
			const unsigned);

#endif /* PACKET_PARSE_H_ */