/* 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 <openssl/asn1.h>

#include <string.h>
#include <time.h>

#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/time_support.h>


int asn1_generalizedtime_to_tm(struct tm *tm, const ASN1_GENERALIZEDTIME *d)
	{
	static const int min[9]={ 0, 0, 1, 1, 0, 0, 0, 0, 0};
	static const int max[9]={99, 99,12,31,23,59,59,12,59};
	char *a;
	int n,i,l,o;

	if (d->type != V_ASN1_GENERALIZEDTIME) return(0);
	l=d->length;
	a=(char *)d->data;
	o=0;
	/* GENERALIZEDTIME is similar to UTCTIME except the year is
         * represented as YYYY. This stuff treats everything as a two digit
         * field so make first two fields 00 to 99
         */
	if (l < 13) goto err;
	for (i=0; i<7; i++)
		{
		if ((i == 6) && ((a[o] == 'Z') ||
			(a[o] == '+') || (a[o] == '-')))
			{
			i++;
			if (tm)
				tm->tm_sec = 0;
			break;
			}
		if ((a[o] < '0') || (a[o] > '9')) goto err;
		n= a[o]-'0';
		if (++o > l) goto err;

		if ((a[o] < '0') || (a[o] > '9')) goto err;
		n=(n*10)+ a[o]-'0';
		if (++o > l) goto err;

		if ((n < min[i]) || (n > max[i])) goto err;
		if (tm)
			{
			switch(i)
				{
			case 0:
				tm->tm_year = n * 100 - 1900;
				break;
			case 1:
				tm->tm_year += n;
				break;
			case 2:
				tm->tm_mon = n - 1;
				break;
			case 3:
				tm->tm_mday = n;
				break;
			case 4:
				tm->tm_hour = n;
				break;
			case 5:
				tm->tm_min = n;
				break;
			case 6:
				tm->tm_sec = n;
				break;
				}
			}
		}
	/* Optional fractional seconds: decimal point followed by one
	 * or more digits.
	 */
	if (a[o] == '.')
		{
		if (++o > l) goto err;
		i = o;
		while ((a[o] >= '0') && (a[o] <= '9') && (o <= l))
			o++;
		/* Must have at least one digit after decimal point */
		if (i == o) goto err;
		}

	if (a[o] == 'Z')
		o++;
	else if ((a[o] == '+') || (a[o] == '-'))
		{
		int offsign = a[o] == '-' ? -1 : 1, offset = 0;
		o++;
		if (o+4 > l) goto err;
		for (i=7; i<9; i++)
			{
			if ((a[o] < '0') || (a[o] > '9')) goto err;
			n= a[o]-'0';
			o++;
			if ((a[o] < '0') || (a[o] > '9')) goto err;
			n=(n*10)+ a[o]-'0';
			if ((n < min[i]) || (n > max[i])) goto err;
			if (tm)
				{
				if (i == 7)
					offset = n * 3600;
				else if (i == 8)
					offset += n * 60;
				}
			o++;
			}
		if (offset && !OPENSSL_gmtime_adj(tm, 0, offset * offsign))
			return 0;
		}
	else if (a[o])
		{
		/* Missing time zone information. */
		goto err;
		}
	return(o == l);
err:
	return(0);
	}

int ASN1_GENERALIZEDTIME_check(const ASN1_GENERALIZEDTIME *d)
	{
	return asn1_generalizedtime_to_tm(NULL, d);
	}

int ASN1_GENERALIZEDTIME_set_string(ASN1_GENERALIZEDTIME *s, const char *str)
	{
	ASN1_GENERALIZEDTIME t;

	t.type=V_ASN1_GENERALIZEDTIME;
	t.length=strlen(str);
	t.data=(unsigned char *)str;
	if (ASN1_GENERALIZEDTIME_check(&t))
		{
		if (s != NULL)
			{
			if (!ASN1_STRING_set((ASN1_STRING *)s,
				(unsigned char *)str,t.length))
				return 0;
			s->type=V_ASN1_GENERALIZEDTIME;
			}
		return(1);
		}
	else
		return(0);
	}

ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_set(ASN1_GENERALIZEDTIME *s,
	     time_t t)
	{
		return ASN1_GENERALIZEDTIME_adj(s, t, 0, 0);
	}

ASN1_GENERALIZEDTIME *ASN1_GENERALIZEDTIME_adj(ASN1_GENERALIZEDTIME *s,
	     time_t t, int offset_day, long offset_sec)
	{
	char *p;
	struct tm *ts;
	struct tm data;
	size_t len = 20; 

	if (s == NULL)
		s=M_ASN1_GENERALIZEDTIME_new();
	if (s == NULL)
		return(NULL);

	ts=OPENSSL_gmtime(&t, &data);
	if (ts == NULL)
		return(NULL);

	if (offset_day || offset_sec)
		{ 
		if (!OPENSSL_gmtime_adj(ts, offset_day, offset_sec))
			return NULL;
		}

	p=(char *)s->data;
	if ((p == NULL) || ((size_t)s->length < len))
		{
		p=OPENSSL_malloc(len);
		if (p == NULL)
			{
			OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
			return(NULL);
			}
		if (s->data != NULL)
			OPENSSL_free(s->data);
		s->data=(unsigned char *)p;
		}

	BIO_snprintf(p,len,"%04d%02d%02d%02d%02d%02dZ",ts->tm_year + 1900,
		     ts->tm_mon+1,ts->tm_mday,ts->tm_hour,ts->tm_min,ts->tm_sec);
	s->length=strlen(p);
	s->type=V_ASN1_GENERALIZEDTIME;
	return(s);
	}