From 42b847ac1ed656383f13646db84568fb23cd45c4 Mon Sep 17 00:00:00 2001
From: Jouni Malinen <j@w1.fi>
Date: Sat, 17 Dec 2016 21:59:40 +0200
Subject: [PATCH] FILS: Fix hashed realm name derivation

P802.11ai/D7.0 changed from CRC32 to SHA256 as the hash algorithm for
the FILS realm name. Update the implementation to match that change.

Signed-off-by: Jouni Malinen <j@w1.fi>
---
 src/ap/ieee802_11_shared.c |  5 +----
 src/common/wpa_common.c    | 13 ++++++++-----
 src/common/wpa_common.h    |  2 +-
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/ap/ieee802_11_shared.c b/src/ap/ieee802_11_shared.c
index 97b1d67ee..d20ddc744 100644
--- a/src/ap/ieee802_11_shared.c
+++ b/src/ap/ieee802_11_shared.c
@@ -639,10 +639,7 @@ u8 * hostapd_eid_fils_indic(struct hostapd_data *hapd, u8 *eid, int hessid)
 		pos += ETH_ALEN;
 	}
 	if (hapd->conf->erp_domain) {
-		u16 hash;
-
-		hash = fils_domain_name_hash(hapd->conf->erp_domain);
-		WPA_PUT_LE16(pos, hash);
+		fils_domain_name_hash(hapd->conf->erp_domain, pos);
 		pos += 2;
 	}
 	*len = pos - len - 1;
diff --git a/src/common/wpa_common.c b/src/common/wpa_common.c
index a87210efb..efc8a45f8 100644
--- a/src/common/wpa_common.c
+++ b/src/common/wpa_common.c
@@ -9,7 +9,6 @@
 #include "includes.h"
 
 #include "common.h"
-#include "utils/crc32.h"
 #include "crypto/md5.h"
 #include "crypto/sha1.h"
 #include "crypto/sha256.h"
@@ -1908,12 +1907,13 @@ int wpa_select_ap_group_cipher(int wpa, int wpa_pairwise, int rsn_pairwise)
 
 
 #ifdef CONFIG_FILS
-u16 fils_domain_name_hash(const char *domain)
+int fils_domain_name_hash(const char *domain, u8 *hash)
 {
 	char buf[255], *wpos = buf;
 	const char *pos = domain;
 	size_t len;
-	u32 crc;
+	const u8 *addr[1];
+	u8 mac[SHA256_MAC_LEN];
 
 	for (len = 0; len < sizeof(buf) && *pos; len++) {
 		if (isalpha(*pos) && isupper(*pos))
@@ -1923,7 +1923,10 @@ u16 fils_domain_name_hash(const char *domain)
 		pos++;
 	}
 
-	crc = crc32((const u8 *) buf, len);
-	return crc & 0xffff;
+	addr[0] = (const u8 *) buf;
+	if (sha256_vector(1, addr, &len, mac) < 0)
+		return -1;
+	os_memcpy(hash, mac, 2);
+	return 0;
 }
 #endif /* CONFIG_FILS */
diff --git a/src/common/wpa_common.h b/src/common/wpa_common.h
index 6d28417e8..ce7479140 100644
--- a/src/common/wpa_common.h
+++ b/src/common/wpa_common.h
@@ -450,6 +450,6 @@ int wpa_parse_cipher(const char *value);
 int wpa_write_ciphers(char *start, char *end, int ciphers, const char *delim);
 int wpa_select_ap_group_cipher(int wpa, int wpa_pairwise, int rsn_pairwise);
 unsigned int wpa_mic_len(int akmp);
-u16 fils_domain_name_hash(const char *domain);
+int fils_domain_name_hash(const char *domain, u8 *hash);
 
 #endif /* WPA_COMMON_H */