openssl/crypto/asn1/a_gentm.c
Pauli 60eba30f60 Memory bounds checking in asn1 code.
Check that sprint, strcpy don't overflow.

Avoid some strlen operations when the previous sprintf return value can be used.

Also fix the undefined behaviour `*(long *)x = y` when x isn't a long or character pointer.
ISO/IEC 9899:1999 6.5/7 for the details.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3869)
2017-07-06 12:59:51 +10:00

310 lines
8.5 KiB
C

/*
* Copyright 1995-2017 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
*/
/*
* GENERALIZEDTIME implementation. Based on UTCTIME
*/
#include <stdio.h>
#include <time.h>
#include "internal/cryptlib.h"
#include <openssl/asn1.h>
#include "asn1_locl.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, min_l = 13, strict = 0;
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
*/
/*
* 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
* 4. fractional seconds are not allowed in GeneralizedTime
*/
if (d->flags & ASN1_STRING_FLAG_X509_TIME) {
min_l = 15;
strict = 1;
}
if (l < min_l)
goto err;
for (i = 0; i < 7; i++) {
if (!strict && (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';
/* incomplete 2-digital number */
if (++o == l)
goto err;
if ((a[o] < '0') || (a[o] > '9'))
goto err;
n = (n * 10) + a[o] - '0';
/* no more bytes to read, but we haven't seen time-zone yet */
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 (strict)
/* RFC 5280 forbids fractional seconds */
goto err;
if (++o == l)
goto err;
i = o;
while ((o < l) && (a[o] >= '0') && (a[o] <= '9'))
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 th '\0' is either the subsequent if or the first
* else if is true.
*/
if (a[o] == 'Z') {
o++;
} else if (!strict && ((a[o] == '+') || (a[o] == '-'))) {
int offsign = a[o] == '-' ? 1 : -1, 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 = 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;
t.flags = 0;
if (ASN1_GENERALIZEDTIME_check(&t)) {
if (s != NULL) {
if (!ASN1_STRING_set((ASN1_STRING *)s, 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;
const size_t len = 20;
ASN1_GENERALIZEDTIME *tmps = NULL;
if (s == NULL)
tmps = ASN1_GENERALIZEDTIME_new();
else
tmps = s;
if (tmps == NULL)
return NULL;
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;
}
p = (char *)tmps->data;
if ((p == NULL) || ((size_t)tmps->length < len)) {
p = OPENSSL_malloc(len);
if (p == NULL) {
ASN1err(ASN1_F_ASN1_GENERALIZEDTIME_ADJ, ERR_R_MALLOC_FAILURE);
goto err;
}
OPENSSL_free(tmps->data);
tmps->data = (unsigned char *)p;
}
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);
tmps->type = V_ASN1_GENERALIZEDTIME;
#ifdef CHARSET_EBCDIC_not
ebcdic2ascii(tmps->data, tmps->data, tmps->length);
#endif
return tmps;
err:
if (s == NULL)
ASN1_GENERALIZEDTIME_free(tmps);
return NULL;
}
const char *_asn1_mon[12] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
int ASN1_GENERALIZEDTIME_print(BIO *bp, const ASN1_GENERALIZEDTIME *tm)
{
char *v;
int gmt = 0;
int i;
int y = 0, M = 0, d = 0, h = 0, m = 0, s = 0;
char *f = NULL;
int f_len = 0;
i = tm->length;
v = (char *)tm->data;
if (i < 12)
goto err;
if (v[i - 1] == 'Z')
gmt = 1;
for (i = 0; i < 12; i++)
if ((v[i] > '9') || (v[i] < '0'))
goto err;
y = (v[0] - '0') * 1000 + (v[1] - '0') * 100
+ (v[2] - '0') * 10 + (v[3] - '0');
M = (v[4] - '0') * 10 + (v[5] - '0');
if ((M > 12) || (M < 1))
goto err;
d = (v[6] - '0') * 10 + (v[7] - '0');
h = (v[8] - '0') * 10 + (v[9] - '0');
m = (v[10] - '0') * 10 + (v[11] - '0');
if (tm->length >= 14 &&
(v[12] >= '0') && (v[12] <= '9') &&
(v[13] >= '0') && (v[13] <= '9')) {
s = (v[12] - '0') * 10 + (v[13] - '0');
/* Check for fractions of seconds. */
if (tm->length >= 15 && v[14] == '.') {
int l = tm->length;
f = &v[14]; /* The decimal point. */
f_len = 1;
while (14 + f_len < l && f[f_len] >= '0' && f[f_len] <= '9')
++f_len;
}
}
if (BIO_printf(bp, "%s %2d %02d:%02d:%02d%.*s %d%s",
_asn1_mon[M - 1], d, h, m, s, f_len, f, y,
(gmt) ? " GMT" : "") <= 0)
return (0);
else
return (1);
err:
BIO_write(bp, "Bad time value", 14);
return (0);
}