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FIPS PRF: Avoid duplicate SHA1Init() functionality

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The initialization values used for the FIPS 186-2 PRF are identical to
the ones used in SHA1Init(), so use that internal function instead of
maintaining a duplicate set of values here. fips186_2_prf() was already
using an internal SHA1Transform() function so using another internal
function does not make this any worse.

Signed-off-by: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2022-05-26 23:40:09 +03:00
parent 5c87fcc154
commit cd92f7f98a
1 changed files with 4 additions and 7 deletions
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11
src/crypto/fips_prf_internal.c
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@ -17,10 +17,11 @@
int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen) int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
{ {
u8 xkey[64]; u8 xkey[64];
u32 t[5], _t[5]; u32 _t[5];
int i, j, m, k; int i, j, m, k;
u8 *xpos = x; u8 *xpos = x;
u32 carry; u32 carry;
struct SHA1Context ctx;
if (seed_len < sizeof(xkey)) if (seed_len < sizeof(xkey))
os_memset(xkey + seed_len, 0, sizeof(xkey) - seed_len); os_memset(xkey + seed_len, 0, sizeof(xkey) - seed_len);
@ -30,11 +31,7 @@ int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
/* FIPS 186-2 + change notice 1 */ /* FIPS 186-2 + change notice 1 */
os_memcpy(xkey, seed, seed_len); os_memcpy(xkey, seed, seed_len);
t[0] = 0x67452301; SHA1Init(&ctx);
t[1] = 0xEFCDAB89;
t[2] = 0x98BADCFE;
t[3] = 0x10325476;
t[4] = 0xC3D2E1F0;
m = xlen / 40; m = xlen / 40;
for (j = 0; j < m; j++) { for (j = 0; j < m; j++) {
@ -43,7 +40,7 @@ int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
/* XVAL = (XKEY + XSEED_j) mod 2^b */ /* XVAL = (XKEY + XSEED_j) mod 2^b */
/* w_i = G(t, XVAL) */ /* w_i = G(t, XVAL) */
os_memcpy(_t, t, 20); os_memcpy(_t, ctx.state, 20);
SHA1Transform(_t, xkey); SHA1Transform(_t, xkey);
_t[0] = host_to_be32(_t[0]); _t[0] = host_to_be32(_t[0]);
_t[1] = host_to_be32(_t[1]); _t[1] = host_to_be32(_t[1]);