From c36358cc7cbdb0dea516e646414f919303430a7a Mon Sep 17 00:00:00 2001 From: Denis Kenzior Date: Fri, 22 Nov 2024 07:15:45 -0800 Subject: [PATCH] handshake: Add pmksa setter & stealer The majority of this patch was authored by Denis Kenzior, but I have appended setting the PMK inside handshake_state_set_pmksa as well as checking if the pmkid exists in handshake_state_steal_pmkid. Authored-by: Denis Kenzior Authored-by: James Prestwood --- Makefile.am | 4 +++ src/handshake.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++ src/handshake.h | 9 ++++++ 3 files changed, 90 insertions(+) diff --git a/Makefile.am b/Makefile.am index 598b8f90..89198289 100644 --- a/Makefile.am +++ b/Makefile.am @@ -458,6 +458,7 @@ unit_test_eap_sim_SOURCES = unit/test-eap-sim.c \ src/eapol.h src/eapol.c \ src/eapolutil.h src/eapolutil.c \ src/handshake.h src/handshake.c \ + src/pmksa.h src/pmksa.c \ src/eap.h src/eap.c src/eap-private.h \ src/util.h src/util.c \ src/simauth.h src/simauth.c \ @@ -517,6 +518,7 @@ unit_test_eapol_SOURCES = unit/test-eapol.c \ src/eapol.h src/eapol.c \ src/eapolutil.h src/eapolutil.c \ src/handshake.h src/handshake.c \ + src/pmksa.h src/pmksa.c \ src/eap.h src/eap.c src/eap-private.h \ src/eap-tls.c src/eap-ttls.c \ src/eap-md5.c src/util.c \ @@ -547,6 +549,7 @@ unit_test_wsc_SOURCES = unit/test-wsc.c src/wscutil.h src/wscutil.c \ src/eapol.h src/eapol.c \ src/eapolutil.h src/eapolutil.c \ src/handshake.h src/handshake.c \ + src/pmksa.h src/pmksa.c \ src/eap.h src/eap.c src/eap-private.h \ src/util.h src/util.c \ src/erp.h src/erp.c \ @@ -565,6 +568,7 @@ unit_test_sae_SOURCES = unit/test-sae.c \ src/crypto.h src/crypto.c \ src/ie.h src/ie.c \ src/handshake.h src/handshake.c \ + src/pmksa.h src/pmksa.c \ src/erp.h src/erp.c \ src/band.h src/band.c \ src/util.h src/util.c \ diff --git a/src/handshake.c b/src/handshake.c index 7fb75dc4..a93143d1 100644 --- a/src/handshake.c +++ b/src/handshake.c @@ -43,6 +43,7 @@ #include "src/handshake.h" #include "src/erp.h" #include "src/band.h" +#include "src/pmksa.h" static inline unsigned int n_ecc_groups(void) { @@ -138,6 +139,9 @@ void handshake_state_unref(struct handshake_state *s) l_free(s->fils_ip_resp_ie); l_free(s->vendor_ies); + if (s->have_pmksa) + l_free(s->pmksa); + if (s->erp_cache) erp_cache_put(s->erp_cache); @@ -701,6 +705,11 @@ void handshake_state_install_ptk(struct handshake_state *s) { s->ptk_complete = true; + if (!s->have_pmksa && IE_AKM_IS_SAE(s->akm_suite)) { + l_debug("Adding PMKSA expiration"); + s->expiration = l_time_now() + pmksa_lifetime(); + } + if (install_tk) { uint32_t cipher = ie_rsn_cipher_suite_to_cipher( s->pairwise_cipher); @@ -1203,3 +1212,71 @@ done: return r; } + +bool handshake_state_set_pmksa(struct handshake_state *s, + struct pmksa *pmksa) +{ + /* checks for both expiration || pmksa being set */ + if (s->expiration) + return false; + + s->pmksa = pmksa; + s->have_pmksa = true; + + handshake_state_set_pmkid(s, pmksa->pmkid); + handshake_state_set_pmk(s, pmksa->pmk, pmksa->pmk_len); + + return true; +} + +static struct pmksa *handshake_state_steal_pmksa(struct handshake_state *s) +{ + struct pmksa *pmksa; + uint64_t now = l_time_now(); + + if (s->have_pmksa) { + pmksa = l_steal_ptr(s->pmksa); + s->have_pmksa = false; + + if (l_time_after(now, pmksa->expiration)) { + l_free(pmksa); + pmksa = NULL; + } + + return pmksa; + } + + if (s->expiration && l_time_after(now, s->expiration)) { + s->expiration = 0; + return NULL; + } + + if (!s->have_pmkid) + return NULL; + + pmksa = l_new(struct pmksa, 1); + pmksa->expiration = s->expiration; + memcpy(pmksa->spa, s->spa, sizeof(s->spa)); + memcpy(pmksa->aa, s->aa, sizeof(s->aa)); + memcpy(pmksa->ssid, s->ssid, s->ssid_len); + pmksa->ssid_len = s->ssid_len; + pmksa->akm = s->akm_suite; + memcpy(pmksa->pmkid, s->pmkid, sizeof(s->pmkid)); + pmksa->pmk_len = s->pmk_len; + memcpy(pmksa->pmk, s->pmk, s->pmk_len); + + return pmksa; +} + +void handshake_state_cache_pmksa(struct handshake_state *s) +{ + struct pmksa *pmksa = handshake_state_steal_pmksa(s); + + l_debug("%p", pmksa); + + if (!pmksa) + return; + + if (L_WARN_ON(pmksa_cache_put(pmksa) < 0)) + l_free(pmksa); +} diff --git a/src/handshake.h b/src/handshake.h index 6c0946d4..c79fc061 100644 --- a/src/handshake.h +++ b/src/handshake.h @@ -29,6 +29,7 @@ struct handshake_state; enum crypto_cipher; struct eapol_frame; +struct pmksa; enum handshake_kde { /* 802.11-2020 Table 12-9 in section 12.7.2 */ @@ -141,6 +142,11 @@ struct handshake_state { bool supplicant_ocvc : 1; bool ext_key_id_capable : 1; bool force_default_ecc_group : 1; + bool have_pmksa : 1; + union { + struct pmksa *pmksa; + uint64_t expiration; + }; uint8_t ssid[SSID_MAX_SIZE]; size_t ssid_len; char *passphrase; @@ -302,6 +308,9 @@ void handshake_state_set_chandef(struct handshake_state *s, int handshake_state_verify_oci(struct handshake_state *s, const uint8_t *oci, size_t oci_len); +bool handshake_state_set_pmksa(struct handshake_state *s, struct pmksa *pmksa); +void handshake_state_cache_pmksa(struct handshake_state *s); + bool handshake_util_ap_ie_matches(const struct ie_rsn_info *msg_info, const uint8_t *scan_ie, bool is_wpa);