4.5-stable review patch. If anyone has any objections, please let me know.
------------------ From: David Howells <[email protected]> commit ac4cbedfdf55455b4c447f17f0fa027dbf02b2a6 upstream. There are still a couple of minor issues in the X.509 leap year handling: (1) To avoid doing a modulus-by-400 in addition to a modulus-by-100 when determining whether the year is a leap year or not, I divided the year by 100 after doing the modulus-by-100, thereby letting the compiler do one instruction for both, and then did a modulus-by-4. Unfortunately, I then passed the now-modified year value to mktime64() to construct a time value. Since this isn't a fast path and since mktime64() does a bunch of divisions, just condense down to "% 400". It's also easier to read. (2) The default month length for any February where the year doesn't divide by four exactly is obtained from the month_length[] array where the value is 29, not 28. This is fixed by altering the table. Reported-by: Rudolf Polzer <[email protected]> Signed-off-by: David Howells <[email protected]> Acked-by: David Woodhouse <[email protected]> Acked-by: Arnd Bergmann <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- crypto/asymmetric_keys/x509_cert_parser.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -494,7 +494,7 @@ int x509_decode_time(time64_t *_t, size unsigned char tag, const unsigned char *value, size_t vlen) { - static const unsigned char month_lengths[] = { 31, 29, 31, 30, 31, 30, + static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; const unsigned char *p = value; unsigned year, mon, day, hour, min, sec, mon_len; @@ -540,9 +540,9 @@ int x509_decode_time(time64_t *_t, size if (year % 4 == 0) { mon_len = 29; if (year % 100 == 0) { - year /= 100; - if (year % 4 != 0) - mon_len = 28; + mon_len = 28; + if (year % 400 == 0) + mon_len = 29; } } }
