diff options
Diffstat (limited to 'package/network/services/hostapd/patches/066-0005-EAP-pwd-Run-through-prf-result-processing-even-if-it.patch')
| -rw-r--r-- | package/network/services/hostapd/patches/066-0005-EAP-pwd-Run-through-prf-result-processing-even-if-it.patch | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/package/network/services/hostapd/patches/066-0005-EAP-pwd-Run-through-prf-result-processing-even-if-it.patch b/package/network/services/hostapd/patches/066-0005-EAP-pwd-Run-through-prf-result-processing-even-if-it.patch new file mode 100644 index 0000000000..9ad474757d --- /dev/null +++ b/package/network/services/hostapd/patches/066-0005-EAP-pwd-Run-through-prf-result-processing-even-if-it.patch @@ -0,0 +1,52 @@ +From 00a6cc73da61b03c146b6c341d0d1e572bcef432 Mon Sep 17 00:00:00 2001 +From: Jouni Malinen <j@w1.fi> +Date: Mon, 24 Jun 2019 23:02:51 +0300 +Subject: [PATCH 5/6] EAP-pwd: Run through prf result processing even if it >= + prime + +This reduces differences in timing and memory access within the +hunting-and-pecking loop for ECC groups that have a prime that is not +close to a power of two (e.g., Brainpool curves). + +Signed-off-by: Jouni Malinen <j@w1.fi> +(cherry picked from commit cd803299ca485eb857e37c88f973fccfbb8600e5) +--- + src/eap_common/eap_pwd_common.c | 13 ++++++++++--- + 1 file changed, 10 insertions(+), 3 deletions(-) + +--- a/src/eap_common/eap_pwd_common.c ++++ b/src/eap_common/eap_pwd_common.c +@@ -155,6 +155,8 @@ int compute_password_element(EAP_PWD_gro + struct crypto_bignum *x_candidate = NULL, *cofactor = NULL; + const struct crypto_bignum *prime; + u8 mask, found_ctr = 0, is_odd = 0; ++ int cmp_prime; ++ unsigned int in_range; + + if (grp->pwe) + return -1; +@@ -247,8 +249,13 @@ int compute_password_element(EAP_PWD_gro + if (primebitlen % 8) + buf_shift_right(prfbuf, primebytelen, + 8 - primebitlen % 8); +- if (const_time_memcmp(prfbuf, prime_bin, primebytelen) >= 0) +- continue; ++ cmp_prime = const_time_memcmp(prfbuf, prime_bin, primebytelen); ++ /* Create a const_time mask for selection based on prf result ++ * being smaller than prime. */ ++ in_range = const_time_fill_msb((unsigned int) cmp_prime); ++ /* The algorithm description would skip the next steps if ++ * cmp_prime >= 0, but go through them regardless to minimize ++ * externally observable differences in behavior. */ + + crypto_bignum_deinit(x_candidate, 1); + x_candidate = crypto_bignum_init_set(prfbuf, primebytelen); +@@ -311,7 +318,7 @@ int compute_password_element(EAP_PWD_gro + goto fail; + mask = const_time_eq(res, check); + found_ctr = const_time_select_u8(found, found_ctr, ctr); +- found |= mask; ++ found |= mask & in_range; + } + if (found == 0) { + wpa_printf(MSG_INFO, |