/* crypto/asn1/a_time.c */
/* ====================================================================
 * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
 *
 * 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.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */


/*-
 * This is an implementation of the ASN1 Time structure which is:
 *    Time ::= CHOICE {
 *      utcTime        UTCTime,
 *      generalTime    GeneralizedTime }
 * written by Steve Henson.
 */

#include <stdio.h>
#include <time.h>
#include "cryptlib.h"
#include <openssl/asn1t.h>
#include "asn1_locl.h"

IMPLEMENT_ASN1_MSTRING(ASN1_TIME, B_ASN1_TIME)

IMPLEMENT_ASN1_FUNCTIONS(ASN1_TIME)

#if 0
int i2d_ASN1_TIME(ASN1_TIME *a, unsigned char **pp)
	{
#ifdef CHARSET_EBCDIC
	/* KLUDGE! We convert to ascii before writing DER */
	char tmp[24];
	ASN1_STRING tmpstr;

	if(a->type == V_ASN1_UTCTIME || a->type == V_ASN1_GENERALIZEDTIME) {
	    int len;

	    tmpstr = *(ASN1_STRING *)a;
	    len = tmpstr.length;
	    ebcdic2ascii(tmp, tmpstr.data, (len >= sizeof tmp) ? sizeof tmp : len);
	    tmpstr.data = tmp;
	    a = (ASN1_GENERALIZEDTIME *) &tmpstr;
	}
#endif
	if(a->type == V_ASN1_UTCTIME || a->type == V_ASN1_GENERALIZEDTIME)
				return(i2d_ASN1_bytes((ASN1_STRING *)a,pp,
				     a->type ,V_ASN1_UNIVERSAL));
	ASN1err(ASN1_F_I2D_ASN1_TIME,ASN1_R_EXPECTING_A_TIME);
	return -1;
	}
#endif


ASN1_TIME *ASN1_TIME_set(ASN1_TIME *s, time_t t)
	{
	return ASN1_TIME_adj(s, t, 0, 0);
	}

ASN1_TIME *ASN1_TIME_adj(ASN1_TIME *s, time_t t,
				int offset_day, long offset_sec)
	{
	struct tm *ts;
	struct tm data;

	ts=OPENSSL_gmtime(&t,&data);
	if (ts == NULL)
		{
		ASN1err(ASN1_F_ASN1_TIME_ADJ, ASN1_R_ERROR_GETTING_TIME);
		return NULL;
		}
	if (offset_day || offset_sec)
		{ 
		if (!OPENSSL_gmtime_adj(ts, offset_day, offset_sec))
			return NULL;
		}
	if((ts->tm_year >= 50) && (ts->tm_year < 150))
			return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec);
	return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec);
	}

int ASN1_TIME_check(const ASN1_TIME *t)
	{
	if (t->type == V_ASN1_GENERALIZEDTIME)
		return ASN1_GENERALIZEDTIME_check(t);
	else if (t->type == V_ASN1_UTCTIME)
		return ASN1_UTCTIME_check(t);
	return 0;
	}

/* Convert an ASN1_TIME structure to GeneralizedTime */
ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(ASN1_TIME *t, ASN1_GENERALIZEDTIME **out)
	{
	ASN1_GENERALIZEDTIME *ret;
	char *str;
	int newlen;

	if (!ASN1_TIME_check(t)) return NULL;

	if (!out || !*out)
		{
		if (!(ret = ASN1_GENERALIZEDTIME_new ()))
			return NULL;
		if (out) *out = ret;
		}
	else ret = *out;

	/* If already GeneralizedTime just copy across */
	if (t->type == V_ASN1_GENERALIZEDTIME)
		{
		if(!ASN1_STRING_set(ret, t->data, t->length))
			return NULL;
		return ret;
		}

	/* grow the string */
	if (!ASN1_STRING_set(ret, NULL, t->length + 2))
		return NULL;
	/* ASN1_STRING_set() allocated 'len + 1' bytes. */
	newlen = t->length + 2 + 1;
	str = (char *)ret->data;
	/* Work out the century and prepend */
	if (t->data[0] >= '5') BUF_strlcpy(str, "19", newlen);
	else BUF_strlcpy(str, "20", newlen);

	BUF_strlcat(str, (char *)t->data, newlen);

	return ret;
	}

int ASN1_TIME_set_string(ASN1_TIME *s, const char *str)
	{
	ASN1_TIME t;

	t.length = strlen(str);
	t.data = (unsigned char *)str;
	t.flags = 0;
	
	t.type = V_ASN1_UTCTIME;

	if (!ASN1_TIME_check(&t))
		{
		t.type = V_ASN1_GENERALIZEDTIME;
		if (!ASN1_TIME_check(&t))
			return 0;
		}
	
	if (s && !ASN1_STRING_copy((ASN1_STRING *)s, (ASN1_STRING *)&t))
			return 0;

	return 1;
	}

static int asn1_time_to_tm(struct tm *tm, const ASN1_TIME *t)
	{
	if (t == NULL)
		{
		time_t now_t;
		time(&now_t);
		if (OPENSSL_gmtime(&now_t, tm))
			return 1;
		return 0;
		}
		
	if (t->type == V_ASN1_UTCTIME)
		return asn1_utctime_to_tm(tm, t);
	else if (t->type == V_ASN1_GENERALIZEDTIME)
		return asn1_generalizedtime_to_tm(tm, t);

	return 0;
	}

int ASN1_TIME_diff(int *pday, int *psec,
			const ASN1_TIME *from, const ASN1_TIME *to)
	{
	struct tm tm_from, tm_to;
	if (!asn1_time_to_tm(&tm_from, from))
		return 0;
	if (!asn1_time_to_tm(&tm_to, to))
		return 0;
	return OPENSSL_gmtime_diff(pday, psec, &tm_from, &tm_to);
	}	
