Make fips186_2_prf() easier for static analyzers

Explicitly validate seed_len to skip memset call with zero length
of copied data at the end of the buffer. This is not really needed,
but it makes the code a bit easier for static analyzers.

Signed-hostap: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2011-11-13 22:59:33 +02:00
parent 7adc3c1296
commit a9ea17491a

View file

@ -28,13 +28,14 @@ int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
u8 *xpos = x; u8 *xpos = x;
u32 carry; u32 carry;
if (seed_len > sizeof(xkey)) if (seed_len < sizeof(xkey))
os_memset(xkey + seed_len, 0, sizeof(xkey) - seed_len);
else
seed_len = sizeof(xkey); seed_len = sizeof(xkey);
/* FIPS 186-2 + change notice 1 */ /* FIPS 186-2 + change notice 1 */
os_memcpy(xkey, seed, seed_len); os_memcpy(xkey, seed, seed_len);
os_memset(xkey + seed_len, 0, 64 - seed_len);
t[0] = 0x67452301; t[0] = 0x67452301;
t[1] = 0xEFCDAB89; t[1] = 0xEFCDAB89;
t[2] = 0x98BADCFE; t[2] = 0x98BADCFE;