/*
* Copyright 1999-2019 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*-
* This is an implementation of the ASN1 Time structure which is:
* Time ::= CHOICE {
* utcTime UTCTime,
* generalTime GeneralizedTime }
*/
#include <stdio.h>
#include <time.h>
#include "crypto/ctype.h"
#include "internal/cryptlib.h"
#include <openssl/asn1t.h>
#include "asn1_local.h"
IMPLEMENT_ASN1_MSTRING(ASN1_TIME, B_ASN1_TIME)
IMPLEMENT_ASN1_FUNCTIONS(ASN1_TIME)
static int is_utc(const int year)
{
if (50 <= year && year <= 149)
return 1;
return 0;
}
static int leap_year(const int year)
{
if (year % 400 == 0 || (year % 100 != 0 && year % 4 == 0))
return 1;
return 0;
}
/*
* Compute the day of the week and the day of the year from the year, month
* and day. The day of the year is straightforward, the day of the week uses
* a form of Zeller's congruence. For this months start with March and are
* numbered 4 through 15.
*/
static void determine_days(struct tm *tm)
{
static const int ydays[12] = {
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
};
int y = tm->tm_year + 1900;
int m = tm->tm_mon;
int d = tm->tm_mday;
int c;
tm->tm_yday = ydays[m] + d - 1;
if (m >= 2) {
/* March and onwards can be one day further into the year */
tm->tm_yday += leap_year(y);
m += 2;
} else {
/* Treat January and February as part of the previous year */
m += 14;
y--;
}
c = y / 100;
y %= 100;
/* Zeller's congruence */
tm->tm_wday = (d + (13 * m) / 5 + y + y / 4 + c / 4 + 5 * c + 6) % 7;
}
int asn1_time_to_tm(struct tm *tm, const ASN1_TIME *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 };
static const int mdays[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
char *a;
int n, i, i2, l, o, min_l = 11, strict = 0, end = 6, btz = 5, md;
struct tm tmp;
#if defined(CHARSET_EBCDIC)
const char upper_z = 0x5A, num_zero = 0x30, period = 0x2E, minus = 0x2D, plus = 0x2B;
#else
const char upper_z = 'Z', num_zero = '0', period = '.', minus = '-', plus = '+';
#endif
/*
* ASN1_STRING_FLAG_X509_TIME is used to enforce RFC 5280
* time string format, in which:
*
* 1. "seconds" is a 'MUST'
* 2. "Zulu" timezone is a 'MUST'
* 3. "+|-" is not allowed to indicate a time zone
*/
if (d->type == V_ASN1_UTCTIME) {
if (d->flags & ASN1_STRING_FLAG_X509_TIME) {
min_l = 13;
strict = 1;
}
} else if (d->type == V_ASN1_GENERALIZEDTIME) {
end = 7;
btz = 6;
if (d->flags & ASN1_STRING_FLAG_X509_TIME) {
min_l = 15;
strict = 1;
} else {
min_l = 13;
}
} else {
return 0;
}
l = d->length;
a = (char *)d->data;
o = 0;
memset(&tmp, 0, sizeof(tmp));
/*
* 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 < min_l)
goto err;
for (i = 0; i < end; i++) {
if (!strict && (i == btz) && ((a[o] == upper_z) || (a[o] == plus) || (a[o] == minus))) {
i++;
break;
}
if (!ascii_isdigit(a[o]))
goto err;
n = a[o] - num_zero;
/* incomplete 2-digital number */
if (++o == l)
goto err;
if (!ascii_isdigit(a[o]))
goto err;
n = (n * 10) + a[o] - num_zero;
/* no more bytes to read, but we haven't seen time-zone yet */
if (++o == l)
goto err;
i2 = (d->type == V_ASN1_UTCTIME) ? i + 1 : i;
if ((n < min[i2]) || (n > max[i2]))
goto err;
switch (i2) {
case 0:
/* UTC will never be here */
tmp.tm_year = n * 100 - 1900;
break;
case 1:
if (d->type == V_ASN1_UTCTIME)
tmp.tm_year = n < 50 ? n + 100 : n;
else
tmp.tm_year += n;
break;
case 2:
tmp.tm_mon = n - 1;
break;
case 3:
/* check if tm_mday is valid in tm_mon */
if (tmp.tm_mon == 1) {
/* it's February */
md = mdays[1] + leap_year(tmp.tm_year + 1900);
} else {
md = mdays[tmp.tm_mon];
}
if (n > md)
goto err;
tmp.tm_mday = n;
determine_days(&tmp);
break;
case 4:
tmp.tm_hour = n;
break;
case 5:
tmp.tm_min = n;
break;
case 6:
tmp.tm_sec = n;
break;
}
}
/*
* Optional fractional seconds: decimal point followed by one or more
* digits.
*/
if (d->type == V_ASN1_GENERALIZEDTIME && a[o] == period) {
if (strict)
/* RFC 5280 forbids fractional seconds */
goto err;
if (++o == l)
goto err;
i = o;
while ((o < l) && ascii_isdigit(a[o]))
o++;
/* Must have at least one digit after decimal point */
if (i == o)
goto err;
/* no more bytes to read, but we haven't seen time-zone yet */
if (o == l)
goto err;
}
/*
* 'o' will never point to '\0' at this point, the only chance
* 'o' can point to '\0' is either the subsequent if or the first
* else if is true.
*/
if (a[o] == upper_z) {
o++;
} else if (!strict && ((a[o] == plus) || (a[o] == minus))) {
int offsign = a[o] == minus ? 1 : -1;
int offset = 0;
o++;
/*
* if not equal, no need to do subsequent checks
* since the following for-loop will add 'o' by 4
* and the final return statement will check if 'l'
* and 'o' are equal.
*/
if (o + 4 != l)
goto err;
for (i = end; i < end + 2; i++) {
if (!ascii_isdigit(a[o]))
goto err;
n = a[o] - num_zero;
o++;
if (!ascii_isdigit(a[o]))
goto err;
n = (n * 10) + a[o] - num_zero;
i2 = (d->type == V_ASN1_UTCTIME) ? i + 1 : i;
if ((n < min[i2]) || (n > max[i2]))
goto err;
/* if tm is NULL, no need to adjust */
if (tm != NULL) {
if (i == end)
offset = n * 3600;
else if (i == end + 1)
offset += n * 60;
}
o++;
}
if (offset && !OPENSSL_gmtime_adj(&tmp, 0, offset * offsign))
goto err;
} else {
/* not Z, or not +/- in non-strict mode */
goto err;
}
if (o == l) {
/* success, check if tm should be filled */
if (tm != NULL)
*tm = tmp;
return 1;
}
err:
return 0;
}
ASN1_TIME *asn1_time_from_tm(ASN1_TIME *s, struct tm *ts, int type)
{
char* p;
ASN1_TIME *tmps = NULL;
const size_t len = 20;
if (type == V_ASN1_UNDEF) {
if (is_utc(ts->tm_year))
type = V_ASN1_UTCTIME;
else
type = V_ASN1_GENERALIZEDTIME;
} else if (type == V_ASN1_UTCTIME) {
if (!is_utc(ts->tm_year))
goto err;
} else if (type != V_ASN1_GENERALIZEDTIME) {
goto err;
}
if (s == NULL)
tmps = ASN1_STRING_new();
else
tmps = s;
if (tmps == NULL)
return NULL;
if (!ASN1_STRING_set(tmps, NULL, len))
goto err;
tmps->type = type;
p = (char*)tmps->data;
if (type == V_ASN1_GENERALIZEDTIME)
tmps->length = 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);
else
tmps->length = 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);
#ifdef CHARSET_EBCDIC
ebcdic2ascii(tmps->data, tmps->data, tmps->length);
#endif
return tmps;
err:
if (tmps != s)
ASN1_STRING_free(tmps);
return NULL;
}
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;
}
return asn1_time_from_tm(s, ts, V_ASN1_UNDEF);
}
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(const ASN1_TIME *t,
ASN1_GENERALIZEDTIME **out)
{
ASN1_GENERALIZEDTIME *ret = NULL;
struct tm tm;
if (!ASN1_TIME_to_tm(t, &tm))
return NULL;
if (out != NULL)
ret = *out;
ret = asn1_time_from_tm(ret, &tm, V_ASN1_GENERALIZEDTIME);
if (out != NULL && ret != NULL)
*out = ret;
return ret;
}
int ASN1_TIME_set_string(ASN1_TIME *s, const char *str)
{
/* Try UTC, if that fails, try GENERALIZED */
if (ASN1_UTCTIME_set_string(s, str))
return 1;
return ASN1_GENERALIZEDTIME_set_string(s, str);
}
int ASN1_TIME_set_string_X509(ASN1_TIME *s, const char *str)
{
ASN1_TIME t;
struct tm tm;
int rv = 0;
t.length = strlen(str);
t.data = (unsigned char *)str;
t.flags = ASN1_STRING_FLAG_X509_TIME;
t.type = V_ASN1_UTCTIME;
if (!ASN1_TIME_check(&t)) {
t.type = V_ASN1_GENERALIZEDTIME;
if (!ASN1_TIME_check(&t))
goto out;
}
/*
* Per RFC 5280 (section 4.1.2.5.), the valid input time
* strings should be encoded with the following rules:
*
* 1. UTC: YYMMDDHHMMSSZ, if YY < 50 (20YY) --> UTC: YYMMDDHHMMSSZ
* 2. UTC: YYMMDDHHMMSSZ, if YY >= 50 (19YY) --> UTC: YYMMDDHHMMSSZ
* 3. G'd: YYYYMMDDHHMMSSZ, if YYYY >= 2050 --> G'd: YYYYMMDDHHMMSSZ
* 4. G'd: YYYYMMDDHHMMSSZ, if YYYY < 2050 --> UTC: YYMMDDHHMMSSZ
*
* Only strings of the 4th rule should be reformatted, but since a
* UTC can only present [1950, 2050), so if the given time string
* is less than 1950 (e.g. 19230419000000Z), we do nothing...
*/
if (s != NULL && t.type == V_ASN1_GENERALIZEDTIME) {
if (!asn1_time_to_tm(&tm, &t))
goto out;
if (is_utc(tm.tm_year)) {
t.length -= 2;
/*
* it's OK to let original t.data go since that's assigned
* to a piece of memory allocated outside of this function.
* new t.data would be freed after ASN1_STRING_copy is done.
*/
t.data = OPENSSL_zalloc(t.length + 1);
if (t.data == NULL)
goto out;
memcpy(t.data, str + 2, t.length);
t.type = V_ASN1_UTCTIME;
}
}
if (s == NULL || ASN1_STRING_copy((ASN1_STRING *)s, (ASN1_STRING *)&t))
rv = 1;
if (t.data != (unsigned char *)str)
OPENSSL_free(t.data);
out:
return rv;
}
int ASN1_TIME_to_tm(const ASN1_TIME *s, struct tm *tm)
{
if (s == NULL) {
time_t now_t;
time(&now_t);
memset(tm, 0, sizeof(*tm));
if (OPENSSL_gmtime(&now_t, tm) != NULL)
return 1;
return 0;
}
return asn1_time_to_tm(tm, s);
}
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(from, &tm_from))
return 0;
if (!ASN1_TIME_to_tm(to, &tm_to))
return 0;
return OPENSSL_gmtime_diff(pday, psec, &tm_from, &tm_to);
}
static const char _asn1_mon[12][4] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
int ASN1_TIME_print(BIO *bp, const ASN1_TIME *tm)
{
char *v;
int gmt = 0, l;
struct tm stm;
const char upper_z = 0x5A, period = 0x2E;
if (!asn1_time_to_tm(&stm, tm)) {
/* asn1_time_to_tm will check the time type */
goto err;
}
l = tm->length;
v = (char *)tm->data;
if (v[l - 1] == upper_z)
gmt = 1;
if (tm->type == V_ASN1_GENERALIZEDTIME) {
char *f = NULL;
int f_len = 0;
/*
* Try to parse fractional seconds. '14' is the place of
* 'fraction point' in a GeneralizedTime string.
*/
if (tm->length > 15 && v[14] == period) {
f = &v[14];
f_len = 1;
while (14 + f_len < l && ascii_isdigit(f[f_len]))
++f_len;
}
return BIO_printf(bp, "%s %2d %02d:%02d:%02d%.*s %d%s",
_asn1_mon[stm.tm_mon], stm.tm_mday, stm.tm_hour,
stm.tm_min, stm.tm_sec, f_len, f, stm.tm_year + 1900,
(gmt ? " GMT" : "")) > 0;
} else {
return BIO_printf(bp, "%s %2d %02d:%02d:%02d %d%s",
_asn1_mon[stm.tm_mon], stm.tm_mday, stm.tm_hour,
stm.tm_min, stm.tm_sec, stm.tm_year + 1900,
(gmt ? " GMT" : "")) > 0;
}
err:
BIO_write(bp, "Bad time value", 14);
return 0;
}
int ASN1_TIME_cmp_time_t(const ASN1_TIME *s, time_t t)
{
struct tm stm, ttm;
int day, sec;
if (!ASN1_TIME_to_tm(s, &stm))
return -2;
if (!OPENSSL_gmtime(&t, &ttm))
return -2;
if (!OPENSSL_gmtime_diff(&day, &sec, &ttm, &stm))
return -2;
if (day > 0 || sec > 0)
return 1;
if (day < 0 || sec < 0)
return -1;
return 0;
}
int ASN1_TIME_normalize(ASN1_TIME *t)
{
struct tm tm;
if (!ASN1_TIME_to_tm(t, &tm))
return 0;
return asn1_time_from_tm(t, &tm, V_ASN1_UNDEF) != NULL;
}
int ASN1_TIME_compare(const ASN1_TIME *a, const ASN1_TIME *b)
{
int day, sec;
if (!ASN1_TIME_diff(&day, &sec, b, a))
return -2;
if (day > 0 || sec > 0)
return 1;
if (day < 0 || sec < 0)
return -1;
return 0;
}