/* $OpenBSD: a_d2i_fp.c,v 1.16 2017/01/29 17:49:22 beck Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <limits.h>
#include <stdio.h>

#include <openssl/asn1.h>
#include <openssl/buffer.h>
#include <openssl/err.h>

static int asn1_d2i_read_bio(BIO *in, BUF_MEM **pb);

#ifndef NO_OLD_ASN1

void *
ASN1_d2i_fp(void *(*xnew)(void), d2i_of_void *d2i, FILE *in, void **x)
{
	BIO *b;
	void *ret;

	if ((b = BIO_new(BIO_s_file())) == NULL) {
		ASN1error(ERR_R_BUF_LIB);
		return (NULL);
	}
	BIO_set_fp(b, in, BIO_NOCLOSE);
	ret = ASN1_d2i_bio(xnew, d2i, b, x);
	BIO_free(b);
	return (ret);
}

void *
ASN1_d2i_bio(void *(*xnew)(void), d2i_of_void *d2i, BIO *in, void **x)
{
	BUF_MEM *b = NULL;
	const unsigned char *p;
	void *ret = NULL;
	int len;

	len = asn1_d2i_read_bio(in, &b);
	if (len < 0)
		goto err;

	p = (unsigned char *)b->data;
	ret = d2i(x, &p, len);

err:
	if (b != NULL)
		BUF_MEM_free(b);
	return (ret);
}

#endif

void *
ASN1_item_d2i_bio(const ASN1_ITEM *it, BIO *in, void *x)
{
	BUF_MEM *b = NULL;
	const unsigned char *p;
	void *ret = NULL;
	int len;

	len = asn1_d2i_read_bio(in, &b);
	if (len < 0)
		goto err;

	p = (const unsigned char *)b->data;
	ret = ASN1_item_d2i(x, &p, len, it);

err:
	if (b != NULL)
		BUF_MEM_free(b);
	return (ret);
}

void *
ASN1_item_d2i_fp(const ASN1_ITEM *it, FILE *in, void *x)
{
	BIO *b;
	char *ret;

	if ((b = BIO_new(BIO_s_file())) == NULL) {
		ASN1error(ERR_R_BUF_LIB);
		return (NULL);
	}
	BIO_set_fp(b, in, BIO_NOCLOSE);
	ret = ASN1_item_d2i_bio(it, b, x);
	BIO_free(b);
	return (ret);
}

#define HEADER_SIZE   8
#define ASN1_CHUNK_INITIAL_SIZE (16 * 1024)
static int
asn1_d2i_read_bio(BIO *in, BUF_MEM **pb)
{
	BUF_MEM *b;
	unsigned char *p;
	int i;
	ASN1_const_CTX c;
	size_t want = HEADER_SIZE;
	int eos = 0;
	size_t off = 0;
	size_t len = 0;

	b = BUF_MEM_new();
	if (b == NULL) {
		ASN1error(ERR_R_MALLOC_FAILURE);
		return -1;
	}

	ERR_clear_error();
	for (;;) {
		if (want >= (len - off)) {
			want -= (len - off);

			if (len + want < len ||
			    !BUF_MEM_grow_clean(b, len + want)) {
				ASN1error(ERR_R_MALLOC_FAILURE);
				goto err;
			}
			i = BIO_read(in, &(b->data[len]), want);
			if ((i < 0) && ((len - off) == 0)) {
				ASN1error(ASN1_R_NOT_ENOUGH_DATA);
				goto err;
			}
			if (i > 0) {
				if (len + i < len) {
					ASN1error(ASN1_R_TOO_LONG);
					goto err;
				}
				len += i;
			}
		}
		/* else data already loaded */

		p = (unsigned char *) & (b->data[off]);
		c.p = p;
		c.inf = ASN1_get_object(&(c.p), &(c.slen), &(c.tag),
		    &(c.xclass), len - off);
		if (c.inf & 0x80) {
			unsigned long e;

			e = ERR_GET_REASON(ERR_peek_error());
			if (e != ASN1_R_TOO_LONG)
				goto err;
			else
				ERR_clear_error(); /* clear error */
		}
		i = c.p - p;	/* header length */
		off += i;	/* end of data */

		if (c.inf & 1) {
			/* no data body so go round again */
			eos++;
			if (eos < 0) {
				ASN1error(ASN1_R_HEADER_TOO_LONG);
				goto err;
			}
			want = HEADER_SIZE;
		} else if (eos && (c.slen == 0) && (c.tag == V_ASN1_EOC)) {
			/* eos value, so go back and read another header */
			eos--;
			if (eos <= 0)
				break;
			else
				want = HEADER_SIZE;
		} else {
			/* suck in c.slen bytes of data */
			want = c.slen;
			if (want > (len - off)) {
				size_t chunk_max = ASN1_CHUNK_INITIAL_SIZE;

				want -= (len - off);
				if (want > INT_MAX /* BIO_read takes an int length */ ||
				    len+want < len) {
					ASN1error(ASN1_R_TOO_LONG);
					goto err;
				}
				while (want > 0) {
					/*
					 * Read content in chunks of increasing size
					 * so we can return an error for EOF without
					 * having to allocate the entire content length
					 * in one go.
					 */
					size_t chunk = want > chunk_max ? chunk_max : want;

					if (!BUF_MEM_grow_clean(b, len + chunk)) {
						ASN1error(ERR_R_MALLOC_FAILURE);
						goto err;
					}
					want -= chunk;
					while (chunk > 0) {
						i = BIO_read(in, &(b->data[len]), chunk);
						if (i <= 0) {
							ASN1error(ASN1_R_NOT_ENOUGH_DATA);
							goto err;
						}
						/*
						 * This can't overflow because |len+want|
						 * didn't overflow.
						 */
						len += i;
						chunk -= i;
					}
					if (chunk_max < INT_MAX/2)
						chunk_max *= 2;
				}
			}
			if (off + c.slen < off) {
				ASN1error(ASN1_R_TOO_LONG);
				goto err;
			}
			off += c.slen;
			if (eos <= 0) {
				break;
			} else
				want = HEADER_SIZE;
		}
	}

	if (off > INT_MAX) {
		ASN1error(ASN1_R_TOO_LONG);
		goto err;
	}

	*pb = b;
	return off;

err:
	if (b != NULL)
		BUF_MEM_free(b);
	return -1;
}
