From 532c9a55210f11c1dc6f75cff4be21f2b334da78 Mon Sep 17 00:00:00 2001
From: James Prestwood <james.prestwood@linux.intel.com>
Date: Thu, 17 Jan 2019 12:25:34 -0800
Subject: [PATCH] eapol: Add OWE cases for different key lengths

In preparation for OWE supporting multiple groups eapol needed some
additional cases to handle the OWE AKM since OWE dictates the KEK,
KCK and MIC key lengths (depending on group).
---
 src/eapol.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 62 insertions(+), 6 deletions(-)

diff --git a/src/eapol.c b/src/eapol.c
index 080b89cf..d901193b 100644
--- a/src/eapol.c
+++ b/src/eapol.c
@@ -130,8 +130,28 @@ bool eapol_verify_mic(enum ie_rsn_akm_suite akm, const uint8_t *kck,
 			checksum = l_checksum_new_cmac_aes(kck, 16);
 			break;
 		case IE_RSN_AKM_SUITE_OWE:
-			checksum = l_checksum_new_hmac(L_CHECKSUM_SHA256,
-								kck, 16);
+			switch (mic_len) {
+			case 16:
+				checksum = l_checksum_new_hmac(
+							L_CHECKSUM_SHA256,
+							kck, 16);
+				break;
+			case 24:
+				checksum = l_checksum_new_hmac(
+							L_CHECKSUM_SHA384,
+							kck, 24);
+				break;
+			case 32:
+				checksum = l_checksum_new_hmac(
+							L_CHECKSUM_SHA512,
+							kck, 32);
+				break;
+			default:
+				l_error("Invalid MIC length of %zu for OWE",
+						mic_len);
+				return false;
+			}
+
 			break;
 		default:
 			return false;
@@ -158,12 +178,24 @@ bool eapol_verify_mic(enum ie_rsn_akm_suite akm, const uint8_t *kck,
 /*
  * IEEE 802.11 Table 12-8 -- Integrity and key-wrap algorithms
  */
-static size_t eapol_get_mic_length(enum ie_rsn_akm_suite akm)
+static size_t eapol_get_mic_length(enum ie_rsn_akm_suite akm, size_t pmk_len)
 {
 	switch (akm) {
 	case IE_RSN_AKM_SUITE_8021X_SUITE_B_SHA384:
 	case IE_RSN_AKM_SUITE_FT_OVER_8021X_SHA384:
 		return 24;
+	case IE_RSN_AKM_SUITE_OWE:
+		switch (pmk_len) {
+		case 32:
+			return 16;
+		case 48:
+			return 24;
+		case 64:
+			return 32;
+		default:
+			l_error("Invalid PMK length of %zu for OWE", pmk_len);
+			return 0;
+		}
 	default:
 		return 16;
 	}
@@ -177,6 +209,7 @@ uint8_t *eapol_decrypt_key_data(enum ie_rsn_akm_suite akm, const uint8_t *kek,
 	const uint8_t *key_data = EAPOL_KEY_DATA(frame, mic_len);
 	size_t expected_len;
 	uint8_t *buf;
+	size_t kek_len;
 
 	switch (frame->key_descriptor_version) {
 	case EAPOL_KEY_DESCRIPTOR_VERSION_HMAC_MD5_ARC4:
@@ -226,7 +259,28 @@ uint8_t *eapol_decrypt_key_data(enum ie_rsn_akm_suite akm, const uint8_t *kek,
 	case EAPOL_KEY_DESCRIPTOR_VERSION_HMAC_SHA1_AES:
 	case EAPOL_KEY_DESCRIPTOR_VERSION_AES_128_CMAC_AES:
 	case EAPOL_KEY_DESCRIPTOR_VERSION_AKM_DEFINED:
-		if (!aes_unwrap(kek, 16, key_data, key_data_len, buf))
+		switch (akm) {
+		case IE_RSN_AKM_SUITE_OWE:
+			switch (mic_len) {
+			case 16:
+				kek_len = 16;
+				break;
+			case 24:
+			case 32:
+				kek_len = 32;
+				break;
+			default:
+				l_error("Invalid MIC length of %zu for OWE",
+						mic_len);
+				goto error;
+			}
+
+			break;
+		default:
+			kek_len = 16;
+		}
+
+		if (!aes_unwrap(kek, kek_len, key_data, key_data_len, buf))
 			goto error;
 
 		break;
@@ -1912,7 +1966,8 @@ static void eapol_eap_results_cb(const uint8_t *msk_data, size_t msk_len,
 	if (msk_len > sizeof(sm->handshake->pmk))
 		msk_len = sizeof(sm->handshake->pmk);
 
-	sm->mic_len = eapol_get_mic_length(sm->handshake->akm_suite);
+	sm->mic_len = eapol_get_mic_length(sm->handshake->akm_suite,
+						sm->handshake->pmk_len);
 
 	switch (sm->handshake->akm_suite) {
 	case IE_RSN_AKM_SUITE_FT_OVER_8021X:
@@ -2172,7 +2227,8 @@ bool eapol_start(struct eapol_sm *sm)
 				l_timeout_create(1, send_eapol_start, sm, NULL);
 	}
 
-	sm->mic_len = eapol_get_mic_length(sm->handshake->akm_suite);
+	sm->mic_len = eapol_get_mic_length(sm->handshake->akm_suite,
+						sm->handshake->pmk_len);
 
 	/* Process any frames received early due to scheduling */
 	if (sm->early_frame) {