/* crypto/asn1/a_utctm.c */
/* 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 <stdio.h>
#include <time.h>
#include "cryptlib.h"
#include <openssl/asn1.h>
#include "asn1_locl.h"

#if 0
int i2d_ASN1_UTCTIME(ASN1_UTCTIME *a, unsigned char **pp)
	{
#ifndef CHARSET_EBCDIC
	return(i2d_ASN1_bytes((ASN1_STRING *)a,pp,
		V_ASN1_UTCTIME,V_ASN1_UNIVERSAL));
#else
	/* KLUDGE! We convert to ascii before writing DER */
	int len;
	char tmp[24];
	ASN1_STRING x = *(ASN1_STRING *)a;

	len = x.length;
	ebcdic2ascii(tmp, x.data, (len >= sizeof tmp) ? sizeof tmp : len);
	x.data = tmp;
	return i2d_ASN1_bytes(&x, pp, V_ASN1_UTCTIME,V_ASN1_UNIVERSAL);
#endif
	}


ASN1_UTCTIME *d2i_ASN1_UTCTIME(ASN1_UTCTIME **a, unsigned char **pp,
	     long length)
	{
	ASN1_UTCTIME *ret=NULL;

	ret=(ASN1_UTCTIME *)d2i_ASN1_bytes((ASN1_STRING **)a,pp,length,
		V_ASN1_UTCTIME,V_ASN1_UNIVERSAL);
	if (ret == NULL)
		{
		ASN1err(ASN1_F_D2I_ASN1_UTCTIME,ERR_R_NESTED_ASN1_ERROR);
		return(NULL);
		}
#ifdef CHARSET_EBCDIC
	ascii2ebcdic(ret->data, ret->data, ret->length);
#endif
	if (!ASN1_UTCTIME_check(ret))
		{
		ASN1err(ASN1_F_D2I_ASN1_UTCTIME,ASN1_R_INVALID_TIME_FORMAT);
		goto err;
		}

	return(ret);
err:
	if ((ret != NULL) && ((a == NULL) || (*a != ret)))
		M_ASN1_UTCTIME_free(ret);
	return(NULL);
	}

#endif

int asn1_utctime_to_tm(struct tm *tm, const ASN1_UTCTIME *d)
	{
	static const int min[8]={ 0, 1, 1, 0, 0, 0, 0, 0};
	static const int max[8]={99,12,31,23,59,59,12,59};
	char *a;
	int n,i,l,o;

	if (d->type != V_ASN1_UTCTIME) return(0);
	l=d->length;
	a=(char *)d->data;
	o=0;

	if (l < 11) goto err;
	for (i=0; i<6; i++)
		{
		if ((i == 5) && ((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 < 50 ? n + 100 : n;
				break;
			case 1:
				tm->tm_mon = n - 1;
				break;
			case 2:
				tm->tm_mday = n;
				break;
			case 3:
				tm->tm_hour = n;
				break;
			case 4:
				tm->tm_min = n;
				break;
			case 5:
				tm->tm_sec = n;
				break;
				}
			}
		}
	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=6; i<8; 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 == 6)
					offset = n * 3600;
				else if (i == 7)
					offset += n * 60;
				}
			o++;
			}
		if (offset && !OPENSSL_gmtime_adj(tm, 0, offset * offsign))
			return 0;
		}
	return o == l;
err:
	return 0;
	}

int ASN1_UTCTIME_check(const ASN1_UTCTIME *d)
	{
	return asn1_utctime_to_tm(NULL, d);
	}

int ASN1_UTCTIME_set_string(ASN1_UTCTIME *s, const char *str)
	{
	ASN1_UTCTIME t;

	t.type=V_ASN1_UTCTIME;
	t.length=strlen(str);
	t.data=(unsigned char *)str;
	if (ASN1_UTCTIME_check(&t))
		{
		if (s != NULL)
			{
			if (!ASN1_STRING_set((ASN1_STRING *)s,
				(unsigned char *)str,t.length))
				return 0;
			s->type = V_ASN1_UTCTIME;
			}
		return(1);
		}
	else
		return(0);
	}

ASN1_UTCTIME *ASN1_UTCTIME_set(ASN1_UTCTIME *s, time_t t)
	{
	return ASN1_UTCTIME_adj(s, t, 0, 0);
	}

ASN1_UTCTIME *ASN1_UTCTIME_adj(ASN1_UTCTIME *s, time_t t,
				int offset_day, long offset_sec)
	{
	char *p;
	struct tm *ts;
	struct tm data;
	size_t len = 20;
	int free_s = 0;

	if (s == NULL)
		{
		free_s = 1;
		s=M_ASN1_UTCTIME_new();
		}
	if (s == NULL)
		goto err;


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

	if (offset_day || offset_sec)
		{ 
		if (!OPENSSL_gmtime_adj(ts, offset_day, offset_sec))
			goto err;
		}

	if((ts->tm_year < 50) || (ts->tm_year >= 150))
		goto err;

	p=(char *)s->data;
	if ((p == NULL) || ((size_t)s->length < len))
		{
		p=OPENSSL_malloc(len);
		if (p == NULL)
			{
			ASN1err(ASN1_F_ASN1_UTCTIME_ADJ,ERR_R_MALLOC_FAILURE);
			goto err;
			}
		if (s->data != NULL)
			OPENSSL_free(s->data);
		s->data=(unsigned char *)p;
		}

	BIO_snprintf(p,len,"%02d%02d%02d%02d%02d%02dZ",ts->tm_year%100,
		     ts->tm_mon+1,ts->tm_mday,ts->tm_hour,ts->tm_min,ts->tm_sec);
	s->length=strlen(p);
	s->type=V_ASN1_UTCTIME;
#ifdef CHARSET_EBCDIC_not
	ebcdic2ascii(s->data, s->data, s->length);
#endif
	return(s);
	err:
	if (free_s && s)
		M_ASN1_UTCTIME_free(s);
	return NULL;
	}


int ASN1_UTCTIME_cmp_time_t(const ASN1_UTCTIME *s, time_t t)
	{
	struct tm stm, ttm;
	int day, sec;

	if (!asn1_utctime_to_tm(&stm, s))
		return -2;

	if (!OPENSSL_gmtime(&t, &ttm))
		return -2;

	if (!OPENSSL_gmtime_diff(&day, &sec, &stm, &ttm))
		return -2;

	if (day > 0)
		return 1;
	if (day < 0)
		return -1;
	if (sec > 0)
		return 1;
	if (sec < 0)
		return -1;
	return 0;
	}


#if 0
time_t ASN1_UTCTIME_get(const ASN1_UTCTIME *s)
	{
	struct tm tm;
	int offset;

	memset(&tm,'\0',sizeof tm);

#define g2(p) (((p)[0]-'0')*10+(p)[1]-'0')
	tm.tm_year=g2(s->data);
	if(tm.tm_year < 50)
		tm.tm_year+=100;
	tm.tm_mon=g2(s->data+2)-1;
	tm.tm_mday=g2(s->data+4);
	tm.tm_hour=g2(s->data+6);
	tm.tm_min=g2(s->data+8);
	tm.tm_sec=g2(s->data+10);
	if(s->data[12] == 'Z')
		offset=0;
	else
		{
		offset=g2(s->data+13)*60+g2(s->data+15);
		if(s->data[12] == '-')
			offset= -offset;
		}
#undef g2

	return mktime(&tm)-offset*60; /* FIXME: mktime assumes the current timezone
	                               * instead of UTC, and unless we rewrite OpenSSL
				       * in Lisp we cannot locally change the timezone
				       * without possibly interfering with other parts
	                               * of the program. timegm, which uses UTC, is
				       * non-standard.
	                               * Also time_t is inappropriate for general
	                               * UTC times because it may a 32 bit type. */
	}
#endif