/* $OpenBSD: asn1_lib.c,v 1.38 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 <string.h>

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

static int asn1_get_length(const unsigned char **pp, int *inf, long *rl, int max);
static void asn1_put_length(unsigned char **pp, int length);

static int
_asn1_check_infinite_end(const unsigned char **p, long len)
{
	/* If there is 0 or 1 byte left, the length check should pick
	 * things up */
	if (len <= 0)
		return (1);
	else if ((len >= 2) && ((*p)[0] == 0) && ((*p)[1] == 0)) {
		(*p) += 2;
		return (1);
	}
	return (0);
}

int
ASN1_check_infinite_end(unsigned char **p, long len)
{
	return _asn1_check_infinite_end((const unsigned char **)p, len);
}

int
ASN1_const_check_infinite_end(const unsigned char **p, long len)
{
	return _asn1_check_infinite_end(p, len);
}

int
ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
    int *pclass, long omax)
{
	int i, ret;
	long l;
	const unsigned char *p= *pp;
	int tag, xclass, inf;
	long max = omax;

	if (!max)
		goto err;
	ret = (*p & V_ASN1_CONSTRUCTED);
	xclass = (*p & V_ASN1_PRIVATE);
	i= *p & V_ASN1_PRIMITIVE_TAG;
	if (i == V_ASN1_PRIMITIVE_TAG) {		/* high-tag */
		p++;
		if (--max == 0)
			goto err;
		l = 0;
		while (*p & 0x80) {
			l <<= 7L;
			l |= *(p++) & 0x7f;
			if (--max == 0)
				goto err;
			if (l > (INT_MAX >> 7L))
				goto err;
		}
		l <<= 7L;
		l |= *(p++) & 0x7f;
		tag = (int)l;
		if (--max == 0)
			goto err;
	} else {
		tag = i;
		p++;
		if (--max == 0)
			goto err;
	}
	*ptag = tag;
	*pclass = xclass;
	if (!asn1_get_length(&p, &inf, plength, (int)max))
		goto err;

	if (inf && !(ret & V_ASN1_CONSTRUCTED))
		goto err;

	if (*plength > (omax - (p - *pp))) {
		ASN1error(ASN1_R_TOO_LONG);
		/* Set this so that even if things are not long enough
		 * the values are set correctly */
		ret |= 0x80;
	}
	*pp = p;
	return (ret | inf);

err:
	ASN1error(ASN1_R_HEADER_TOO_LONG);
	return (0x80);
}

static int
asn1_get_length(const unsigned char **pp, int *inf, long *rl, int max)
{
	const unsigned char *p= *pp;
	unsigned long ret = 0;
	unsigned int i;

	if (max-- < 1)
		return (0);
	if (*p == 0x80) {
		*inf = 1;
		ret = 0;
		p++;
	} else {
		*inf = 0;
		i= *p & 0x7f;
		if (*(p++) & 0x80) {
			if (max < (int)i)
				return (0);
			/* skip leading zeroes */
			while (i && *p == 0) {
				p++;
				i--;
			}
			if (i > sizeof(long))
				return 0;
			while (i-- > 0) {
				ret <<= 8L;
				ret |= *(p++);
			}
		} else
			ret = i;
	}
	if (ret > LONG_MAX)
		return 0;
	*pp = p;
	*rl = (long)ret;
	return (1);
}

/* class 0 is constructed
 * constructed == 2 for indefinite length constructed */
void
ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
    int xclass)
{
	unsigned char *p= *pp;
	int i, ttag;

	i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
	i |= (xclass & V_ASN1_PRIVATE);
	if (tag < 31)
		*(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG);
	else {
		*(p++) = i | V_ASN1_PRIMITIVE_TAG;
		for(i = 0, ttag = tag; ttag > 0; i++)
			ttag >>= 7;
		ttag = i;
		while (i-- > 0) {
			p[i] = tag & 0x7f;
			if (i != (ttag - 1))
				p[i] |= 0x80;
			tag >>= 7;
		}
		p += ttag;
	}
	if (constructed == 2)
		*(p++) = 0x80;
	else
		asn1_put_length(&p, length);
	*pp = p;
}

int
ASN1_put_eoc(unsigned char **pp)
{
	unsigned char *p = *pp;

	*p++ = 0;
	*p++ = 0;
	*pp = p;
	return 2;
}

static void
asn1_put_length(unsigned char **pp, int length)
{
	unsigned char *p= *pp;

	int i, l;
	if (length <= 127)
		*(p++) = (unsigned char)length;
	else {
		l = length;
		for (i = 0; l > 0; i++)
			l >>= 8;
		*(p++) = i | 0x80;
		l = i;
		while (i-- > 0) {
			p[i] = length & 0xff;
			length >>= 8;
		}
		p += l;
	}
	*pp = p;
}

int
ASN1_object_size(int constructed, int length, int tag)
{
	int ret;

	ret = length;
	ret++;
	if (tag >= 31) {
		while (tag > 0) {
			tag >>= 7;
			ret++;
		}
	}
	if (constructed == 2)
		return ret + 3;
	ret++;
	if (length > 127) {
		while (length > 0) {
			length >>= 8;
			ret++;
		}
	}
	return (ret);
}

static int
_asn1_Finish(ASN1_const_CTX *c)
{
	if ((c->inf == (1|V_ASN1_CONSTRUCTED)) && (!c->eos)) {
		if (!ASN1_const_check_infinite_end(&c->p, c->slen)) {
			c->error = ERR_R_MISSING_ASN1_EOS;
			return (0);
		}
	}
	if (((c->slen != 0) && !(c->inf & 1)) ||
	    ((c->slen < 0) && (c->inf & 1))) {
		c->error = ERR_R_ASN1_LENGTH_MISMATCH;
		return (0);
	}
	return (1);
}

int
asn1_Finish(ASN1_CTX *c)
{
	return _asn1_Finish((ASN1_const_CTX *)c);
}

int
asn1_const_Finish(ASN1_const_CTX *c)
{
	return _asn1_Finish(c);
}

int
asn1_GetSequence(ASN1_const_CTX *c, long *length)
{
	const unsigned char *q;

	q = c->p;
	c->inf = ASN1_get_object(&(c->p), &(c->slen), &(c->tag), &(c->xclass),
	    *length);
	if (c->inf & 0x80) {
		c->error = ERR_R_BAD_GET_ASN1_OBJECT_CALL;
		return (0);
	}
	if (c->tag != V_ASN1_SEQUENCE) {
		c->error = ERR_R_EXPECTING_AN_ASN1_SEQUENCE;
		return (0);
	}
	(*length) -= (c->p - q);
	if (c->max && (*length < 0)) {
		c->error = ERR_R_ASN1_LENGTH_MISMATCH;
		return (0);
	}
	if (c->inf == (1|V_ASN1_CONSTRUCTED))
		c->slen= *length+ *(c->pp) - c->p;
	c->eos = 0;
	return (1);
}

int
ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str)
{
	if (str == NULL)
		return 0;
	dst->type = str->type;
	if (!ASN1_STRING_set(dst, str->data, str->length))
		return 0;
	dst->flags = str->flags;
	return 1;
}

ASN1_STRING *
ASN1_STRING_dup(const ASN1_STRING *str)
{
	ASN1_STRING *ret;

	if (!str)
		return NULL;
	ret = ASN1_STRING_new();
	if (!ret)
		return NULL;
	if (!ASN1_STRING_copy(ret, str)) {
		ASN1_STRING_free(ret);
		return NULL;
	}
	return ret;
}

int
ASN1_STRING_set(ASN1_STRING *str, const void *_data, int len)
{
	const char *data = _data;

	if (len < 0) {
		if (data == NULL)
			return (0);
		else
			len = strlen(data);
	}
	if ((str->length < len) || (str->data == NULL)) {
		unsigned char *tmp;
		tmp = realloc(str->data, len + 1);
		if (tmp == NULL) {
			ASN1error(ERR_R_MALLOC_FAILURE);
			return (0);
		}
		str->data = tmp;
	}
	str->length = len;
	if (data != NULL) {
		memmove(str->data, data, len);
	}
	str->data[str->length]='\0';
	return (1);
}

void
ASN1_STRING_set0(ASN1_STRING *str, void *data, int len)
{
	if (str->data != NULL)
		explicit_bzero(str->data, str->length);
	free(str->data);
	str->data = data;
	str->length = len;
}

ASN1_STRING *
ASN1_STRING_new(void)
{
	return (ASN1_STRING_type_new(V_ASN1_OCTET_STRING));
}

ASN1_STRING *
ASN1_STRING_type_new(int type)
{
	ASN1_STRING *ret;

	ret = malloc(sizeof(ASN1_STRING));
	if (ret == NULL) {
		ASN1error(ERR_R_MALLOC_FAILURE);
		return (NULL);
	}
	ret->length = 0;
	ret->type = type;
	ret->data = NULL;
	ret->flags = 0;
	return (ret);
}

void
ASN1_STRING_free(ASN1_STRING *a)
{
	if (a == NULL)
		return;
	if (a->data != NULL && !(a->flags & ASN1_STRING_FLAG_NDEF)) {
		explicit_bzero(a->data, a->length);
		free(a->data);
	}
	free(a);
}

int
ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b)
{
	int i;

	i = (a->length - b->length);
	if (i == 0) {
		i = memcmp(a->data, b->data, a->length);
		if (i == 0)
			return (a->type - b->type);
		else
			return (i);
	} else
		return (i);
}

void
asn1_add_error(const unsigned char *address, int offset)
{
	ERR_asprintf_error_data("offset=%d", offset);
}

int
ASN1_STRING_length(const ASN1_STRING *x)
{
	return (x->length);
}

void
ASN1_STRING_length_set(ASN1_STRING *x, int len)
{
	x->length = len;
}

int
ASN1_STRING_type(ASN1_STRING *x)
{
	return (x->type);
}

unsigned char *
ASN1_STRING_data(ASN1_STRING *x)
{
	return (x->data);
}
