/* $OpenBSD: asn1pars.c,v 1.24 2014/06/12 15:49:27 deraadt 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.]
 */

/* A nice addition from Dr Stephen Henson <steve@openssl.org> to
 * add the -strparse option which parses nested binary structures
 */

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

#include "apps.h"

#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/x509.h>

/* -inform arg	- input format - default PEM (DER or PEM)
 * -in arg	- input file - default stdin
 * -i		- indent the details by depth
 * -offset	- where in the file to start
 * -length	- how many bytes to use
 * -oid file	- extra oid description file
 */

int asn1parse_main(int, char **);

static int do_generate(BIO * bio, char *genstr, char *genconf, BUF_MEM * buf);

int
asn1parse_main(int argc, char **argv)
{
	int i, badops = 0, offset = 0, ret = 1, j;
	unsigned int length = 0;
	long num, tmplen;
	BIO *in = NULL, *out = NULL, *b64 = NULL, *derout = NULL;
	int informat, indent = 0, noout = 0, dump = 0;
	char *infile = NULL, *str = NULL, *prog, *oidfile = NULL, *derfile = NULL;
	char *genstr = NULL, *genconf = NULL;
	const char *errstr = NULL;
	unsigned char *tmpbuf;
	const unsigned char *ctmpbuf;
	BUF_MEM *buf = NULL;
	STACK_OF(OPENSSL_STRING) * osk = NULL;
	ASN1_TYPE *at = NULL;

	informat = FORMAT_PEM;

	if (!load_config(bio_err, NULL))
		goto end;

	prog = argv[0];
	argc--;
	argv++;
	if ((osk = sk_OPENSSL_STRING_new_null()) == NULL) {
		BIO_printf(bio_err, "Memory allocation failure\n");
		goto end;
	}
	while (argc >= 1) {
		if (strcmp(*argv, "-inform") == 0) {
			if (--argc < 1)
				goto bad;
			informat = str2fmt(*(++argv));
		} else if (strcmp(*argv, "-in") == 0) {
			if (--argc < 1)
				goto bad;
			infile = *(++argv);
		} else if (strcmp(*argv, "-out") == 0) {
			if (--argc < 1)
				goto bad;
			derfile = *(++argv);
		} else if (strcmp(*argv, "-i") == 0) {
			indent = 1;
		} else if (strcmp(*argv, "-noout") == 0)
			noout = 1;
		else if (strcmp(*argv, "-oid") == 0) {
			if (--argc < 1)
				goto bad;
			oidfile = *(++argv);
		} else if (strcmp(*argv, "-offset") == 0) {
			if (--argc < 1)
				goto bad;
			offset = strtonum(*(++argv), 0, INT_MAX, &errstr);
			if (errstr)
				goto bad;
		} else if (strcmp(*argv, "-length") == 0) {
			if (--argc < 1)
				goto bad;
			length = strtonum(*(++argv), 1, UINT_MAX, &errstr);
			if (errstr)
				goto bad;
		} else if (strcmp(*argv, "-dump") == 0) {
			dump = -1;
		} else if (strcmp(*argv, "-dlimit") == 0) {
			if (--argc < 1)
				goto bad;
			dump = strtonum(*(++argv), 1, INT_MAX, &errstr);
			if (errstr)
				goto bad;
		} else if (strcmp(*argv, "-strparse") == 0) {
			if (--argc < 1)
				goto bad;
			sk_OPENSSL_STRING_push(osk, *(++argv));
		} else if (strcmp(*argv, "-genstr") == 0) {
			if (--argc < 1)
				goto bad;
			genstr = *(++argv);
		} else if (strcmp(*argv, "-genconf") == 0) {
			if (--argc < 1)
				goto bad;
			genconf = *(++argv);
		} else {
			BIO_printf(bio_err, "unknown option %s\n", *argv);
			badops = 1;
			break;
		}
		argc--;
		argv++;
	}

	if (badops) {
bad:
		BIO_printf(bio_err, "%s [options] <infile\n", prog);
		BIO_printf(bio_err, "where options are\n");
		BIO_printf(bio_err, " -inform arg   input format - one of DER PEM\n");
		BIO_printf(bio_err, " -in arg       input file\n");
		BIO_printf(bio_err, " -out arg      output file (output format is always DER\n");
		BIO_printf(bio_err, " -noout arg    don't produce any output\n");
		BIO_printf(bio_err, " -offset arg   offset into file\n");
		BIO_printf(bio_err, " -length arg   length of section in file\n");
		BIO_printf(bio_err, " -i            indent entries\n");
		BIO_printf(bio_err, " -dump         dump unknown data in hex form\n");
		BIO_printf(bio_err, " -dlimit arg   dump the first arg bytes of unknown data in hex form\n");
		BIO_printf(bio_err, " -oid file     file of extra oid definitions\n");
		BIO_printf(bio_err, " -strparse offset\n");
		BIO_printf(bio_err, "               a series of these can be used to 'dig' into multiple\n");
		BIO_printf(bio_err, "               ASN1 blob wrappings\n");
		BIO_printf(bio_err, " -genstr str   string to generate ASN1 structure from\n");
		BIO_printf(bio_err, " -genconf file file to generate ASN1 structure from\n");
		goto end;
	}
	ERR_load_crypto_strings();

	in = BIO_new(BIO_s_file());
	out = BIO_new(BIO_s_file());
	if ((in == NULL) || (out == NULL)) {
		ERR_print_errors(bio_err);
		goto end;
	}
	BIO_set_fp(out, stdout, BIO_NOCLOSE | BIO_FP_TEXT);

	if (oidfile != NULL) {
		if (BIO_read_filename(in, oidfile) <= 0) {
			BIO_printf(bio_err, "problems opening %s\n", oidfile);
			ERR_print_errors(bio_err);
			goto end;
		}
		OBJ_create_objects(in);
	}
	if (infile == NULL)
		BIO_set_fp(in, stdin, BIO_NOCLOSE);
	else {
		if (BIO_read_filename(in, infile) <= 0) {
			perror(infile);
			goto end;
		}
	}

	if (derfile) {
		if (!(derout = BIO_new_file(derfile, "wb"))) {
			BIO_printf(bio_err, "problems opening %s\n", derfile);
			ERR_print_errors(bio_err);
			goto end;
		}
	}
	if ((buf = BUF_MEM_new()) == NULL)
		goto end;
	if (!BUF_MEM_grow(buf, BUFSIZ * 8))
		goto end;	/* Pre-allocate :-) */

	if (genstr || genconf) {
		num = do_generate(bio_err, genstr, genconf, buf);
		if (num < 0) {
			ERR_print_errors(bio_err);
			goto end;
		}
	} else {

		if (informat == FORMAT_PEM) {
			BIO *tmp;

			if ((b64 = BIO_new(BIO_f_base64())) == NULL)
				goto end;
			BIO_push(b64, in);
			tmp = in;
			in = b64;
			b64 = tmp;
		}
		num = 0;
		for (;;) {
			if (!BUF_MEM_grow(buf, (int) num + BUFSIZ))
				goto end;
			i = BIO_read(in, &(buf->data[num]), BUFSIZ);
			if (i <= 0)
				break;
			num += i;
		}
	}
	str = buf->data;

	/* If any structs to parse go through in sequence */

	if (sk_OPENSSL_STRING_num(osk)) {
		tmpbuf = (unsigned char *) str;
		tmplen = num;
		for (i = 0; i < sk_OPENSSL_STRING_num(osk); i++) {
			ASN1_TYPE *atmp;
			int typ;
			j = strtonum(sk_OPENSSL_STRING_value(osk, i),
			    1, INT_MAX, &errstr);
			if (errstr) {
				BIO_printf(bio_err,
				    "'%s' is an invalid number: %s\n",
				    sk_OPENSSL_STRING_value(osk, i), errstr);
				continue;
			}
			tmpbuf += j;
			tmplen -= j;
			atmp = at;
			ctmpbuf = tmpbuf;
			at = d2i_ASN1_TYPE(NULL, &ctmpbuf, tmplen);
			ASN1_TYPE_free(atmp);
			if (!at) {
				BIO_printf(bio_err, "Error parsing structure\n");
				ERR_print_errors(bio_err);
				goto end;
			}
			typ = ASN1_TYPE_get(at);
			if ((typ == V_ASN1_OBJECT) ||
			    (typ == V_ASN1_NULL)) {
				BIO_printf(bio_err, "Can't parse %s type\n",
				    typ == V_ASN1_NULL ? "NULL" : "OBJECT");
				ERR_print_errors(bio_err);
				goto end;
			}
			/* hmm... this is a little evil but it works */
			tmpbuf = at->value.asn1_string->data;
			tmplen = at->value.asn1_string->length;
		}
		str = (char *) tmpbuf;
		num = tmplen;
	}
	if (offset >= num) {
		BIO_printf(bio_err, "Error: offset too large\n");
		goto end;
	}
	num -= offset;

	if ((length == 0) || ((long) length > num))
		length = (unsigned int) num;
	if (derout) {
		if (BIO_write(derout, str + offset, length) != (int) length) {
			BIO_printf(bio_err, "Error writing output\n");
			ERR_print_errors(bio_err);
			goto end;
		}
	}
	if (!noout &&
	    !ASN1_parse_dump(out, (unsigned char *) &(str[offset]), length,
		indent, dump)) {
		ERR_print_errors(bio_err);
		goto end;
	}
	ret = 0;
end:
	BIO_free(derout);
	if (in != NULL)
		BIO_free(in);
	if (out != NULL)
		BIO_free_all(out);
	if (b64 != NULL)
		BIO_free(b64);
	if (ret != 0)
		ERR_print_errors(bio_err);
	if (buf != NULL)
		BUF_MEM_free(buf);
	if (at != NULL)
		ASN1_TYPE_free(at);
	if (osk != NULL)
		sk_OPENSSL_STRING_free(osk);
	OBJ_cleanup();
	
	return (ret);
}

static int
do_generate(BIO * bio, char *genstr, char *genconf, BUF_MEM * buf)
{
	CONF *cnf = NULL;
	int len;
	long errline;
	unsigned char *p;
	ASN1_TYPE *atyp = NULL;

	if (genconf) {
		cnf = NCONF_new(NULL);
		if (!NCONF_load(cnf, genconf, &errline))
			goto conferr;
		if (!genstr)
			genstr = NCONF_get_string(cnf, "default", "asn1");
		if (!genstr) {
			BIO_printf(bio, "Can't find 'asn1' in '%s'\n", genconf);
			goto err;
		}
	}
	atyp = ASN1_generate_nconf(genstr, cnf);
	NCONF_free(cnf);
	cnf = NULL;

	if (!atyp)
		return -1;

	len = i2d_ASN1_TYPE(atyp, NULL);

	if (len <= 0)
		goto err;

	if (!BUF_MEM_grow(buf, len))
		goto err;

	p = (unsigned char *) buf->data;

	i2d_ASN1_TYPE(atyp, &p);

	ASN1_TYPE_free(atyp);
	return len;

conferr:

	if (errline > 0)
		BIO_printf(bio, "Error on line %ld of config file '%s'\n",
		    errline, genconf);
	else
		BIO_printf(bio, "Error loading config file '%s'\n", genconf);

err:
	NCONF_free(cnf);
	ASN1_TYPE_free(atyp);

	return -1;

}