diff --git a/src/modules/rlm_eap/types/rlm_eap_pwd/eap_pwd.c b/src/modules/rlm_eap/types/rlm_eap_pwd/eap_pwd.c index 7f91e4b230..848ca2055e 100644 --- a/src/modules/rlm_eap/types/rlm_eap_pwd/eap_pwd.c +++ b/src/modules/rlm_eap/types/rlm_eap_pwd/eap_pwd.c @@ -373,11 +373,26 @@ int process_peer_commit (pwd_session_t *session, uint8_t *in, size_t in_len, BN_ data_len = BN_num_bytes(session->order); BN_bin2bn(ptr, data_len, session->peer_scalar); + /* validate received scalar */ + if (BN_is_zero(session->peer_scalar) || + BN_is_one(session->peer_scalar) || + BN_cmp(session->peer_scalar, session->order) >= 0) { + ERROR("Peer's scalar is not within the allowed range"); + goto finish; + } + if (!EC_POINT_set_affine_coordinates_GFp(session->group, session->peer_element, x, y, bnctx)) { DEBUG2("pwd: unable to get coordinates of peer's element"); goto finish; } + /* validate received element */ + if (!EC_POINT_is_on_curve(session->group, session->peer_element, bnctx) || + EC_POINT_is_at_infinity(session->group, session->peer_element)) { + ERROR("Peer's element is not a point on the elliptic curve"); + goto finish; + } + /* check to ensure peer's element is not in a small sub-group */ if (BN_cmp(cofactor, BN_value_one())) { if (!EC_POINT_mul(session->group, point, NULL, session->peer_element, cofactor, NULL)) { @@ -391,6 +406,13 @@ int process_peer_commit (pwd_session_t *session, uint8_t *in, size_t in_len, BN_ } } + /* detect reflection attacks */ + if (BN_cmp(session->peer_scalar, session->my_scalar) == 0 || + EC_POINT_cmp(session->group, session->peer_element, session->my_element, bnctx) == 0) { + ERROR("Reflection attack detected"); + goto finish; + } + /* compute the shared key, k */ if ((!EC_POINT_mul(session->group, K, NULL, session->pwe, session->peer_scalar, bnctx)) || (!EC_POINT_add(session->group, K, K, session->peer_element, bnctx)) ||