mka: Extend CAK/CKN-from-EAP-MSK API to pass in MSK length

This can be used to allow 256-bit key hierarchy to be derived from
EAP-based authentication. For now, the MSK length is hardcoded to 128
bits, so the previous behavior is maintained.

Signed-off-by: Jouni Malinen <j@w1.fi>

diff --git a/src/pae/ieee802_1x_kay.c b/src/pae/ieee802_1x_kay.c
index 3127bf63cf8d13efc76185e28a7958a64db464a5..a8b3fc2ae23d42e896d8b6996916ad0124342598 100644 (file)
--- a/src/pae/ieee802_1x_kay.c
+++ b/src/pae/ieee802_1x_kay.c
@@ -66,8 +66,8 @@ static struct mka_alg mka_alg_tbl[] = {
 
                .icv_len = DEFAULT_ICV_LEN,
 
-               .cak_trfm = ieee802_1x_cak_128bits_aes_cmac,
-               .ckn_trfm = ieee802_1x_ckn_128bits_aes_cmac,
+               .cak_trfm = ieee802_1x_cak_aes_cmac,
+               .ckn_trfm = ieee802_1x_ckn_aes_cmac,
                .kek_trfm = ieee802_1x_kek_aes_cmac,
                .ick_trfm = ieee802_1x_ick_aes_cmac,
                .icv_hash = ieee802_1x_icv_aes_cmac,

diff --git a/src/pae/ieee802_1x_kay_i.h b/src/pae/ieee802_1x_kay_i.h
index 9799f6251d1eaa2c5abd09e58785849cbce1eb56..06eaacfa60d6324730ffe991430fb41a107f57da 100644 (file)
--- a/src/pae/ieee802_1x_kay_i.h
+++ b/src/pae/ieee802_1x_kay_i.h
@@ -68,9 +68,10 @@ struct mka_alg {
        u8 parameter[4];
        size_t icv_len;
 
-       int (*cak_trfm)(const u8 *msk, const u8 *mac1, const u8 *mac2, u8 *cak);
-       int (*ckn_trfm)(const u8 *msk, const u8 *mac1, const u8 *mac2,
-                       const u8 *sid, size_t sid_len, u8 *ckn);
+       int (*cak_trfm)(const u8 *msk, size_t msk_bytes, const u8 *mac1,
+                       const u8 *mac2, u8 *cak, size_t cak_bytes);
+       int (*ckn_trfm)(const u8 *msk, size_t msk_bytes, const u8 *mac1,
+                       const u8 *mac2, const u8 *sid, size_t sid_len, u8 *ckn);
        int (*kek_trfm)(const u8 *cak, size_t cak_bytes,
                        const u8 *ckn, size_t ckn_len,
                        u8 *kek, size_t kek_bytes);

diff --git a/src/pae/ieee802_1x_key.c b/src/pae/ieee802_1x_key.c
index 4fafba83a23a4a649196fb50d00f46e89236861d..d63ca7f7038acded1ba1697e647a2cb8a4249456 100644 (file)
--- a/src/pae/ieee802_1x_key.c
+++ b/src/pae/ieee802_1x_key.c
@@ -82,33 +82,32 @@ static int aes_kdf(const u8 *kdk, size_t kdk_bits,
 }
 
 
-/********** AES-CMAC-128 **********/
 /**
- * ieee802_1x_cak_128bits_aes_cmac
+ * ieee802_1x_cak_aes_cmac
  *
  * IEEE Std 802.1X-2010, 6.2.2
  * CAK = KDF(Key, Label, mac1 | mac2, CAKlength)
  */
-int ieee802_1x_cak_128bits_aes_cmac(const u8 *msk, const u8 *mac1,
-                                   const u8 *mac2, u8 *cak)
+int ieee802_1x_cak_aes_cmac(const u8 *msk, size_t msk_bytes, const u8 *mac1,
+                           const u8 *mac2, u8 *cak, size_t cak_bytes)
 {
        u8 context[2 * ETH_ALEN];
 
        joint_two_mac(mac1, mac2, context);
-       return aes_kdf(msk, 128, "IEEE8021 EAP CAK",
-                      context, sizeof(context) * 8, 128, cak);
+       return aes_kdf(msk, 8 * msk_bytes, "IEEE8021 EAP CAK",
+                      context, sizeof(context) * 8, 8 * cak_bytes, cak);
 }
 
 
 /**
- * ieee802_1x_ckn_128bits_aes_cmac
+ * ieee802_1x_ckn_aes_cmac
  *
  * IEEE Std 802.1X-2010, 6.2.2
  * CKN = KDF(Key, Label, ID | mac1 | mac2, CKNlength)
  */
-int ieee802_1x_ckn_128bits_aes_cmac(const u8 *msk, const u8 *mac1,
-                                   const u8 *mac2, const u8 *sid,
-                                   size_t sid_bytes, u8 *ckn)
+int ieee802_1x_ckn_aes_cmac(const u8 *msk, size_t msk_bytes, const u8 *mac1,
+                           const u8 *mac2, const u8 *sid,
+                           size_t sid_bytes, u8 *ckn)
 {
        int res;
        u8 *context;
@@ -122,8 +121,8 @@ int ieee802_1x_ckn_128bits_aes_cmac(const u8 *msk, const u8 *mac1,
        os_memcpy(context, sid, sid_bytes);
        joint_two_mac(mac1, mac2, context + sid_bytes);
 
-       res = aes_kdf(msk, 128, "IEEE8021 EAP CKN", context, ctx_len * 8,
-                     128, ckn);
+       res = aes_kdf(msk, 8 * msk_bytes, "IEEE8021 EAP CKN",
+                     context, ctx_len * 8, 128, ckn);
        os_free(context);
        return res;
 }

diff --git a/src/pae/ieee802_1x_key.h b/src/pae/ieee802_1x_key.h
index dc6603a17e30afbb6955ace3ea5a8f242b7f39e7..1f9058de5cccfe9b899b207f1643c07f0626413d 100644 (file)
--- a/src/pae/ieee802_1x_key.h
+++ b/src/pae/ieee802_1x_key.h
@@ -9,11 +9,11 @@
 #ifndef IEEE802_1X_KEY_H
 #define IEEE802_1X_KEY_H
 
-int ieee802_1x_cak_128bits_aes_cmac(const u8 *msk, const u8 *mac1,
-                                   const u8 *mac2, u8 *cak);
-int ieee802_1x_ckn_128bits_aes_cmac(const u8 *msk, const u8 *mac1,
-                                   const u8 *mac2, const u8 *sid,
-                                   size_t sid_bytes, u8 *ckn);
+int ieee802_1x_cak_aes_cmac(const u8 *msk, size_t msk_bytes, const u8 *mac1,
+                           const u8 *mac2, u8 *cak, size_t cak_bytes);
+int ieee802_1x_ckn_aes_cmac(const u8 *msk, size_t msk_bytes, const u8 *mac1,
+                           const u8 *mac2, const u8 *sid,
+                           size_t sid_bytes, u8 *ckn);
 int ieee802_1x_kek_aes_cmac(const u8 *cak, size_t cak_bytes, const u8 *ckn,
                            size_t ckn_bytes, u8 *kek, size_t kek_bytes);
 int ieee802_1x_ick_aes_cmac(const u8 *cak, size_t cak_bytes, const u8 *ckn,

diff --git a/wpa_supplicant/wpas_kay.c b/wpa_supplicant/wpas_kay.c
index 707e5bb6d6a4022bd211995375cf199d16717124..41477d514d3f09e905273226d0f2b98d2a98a847 100644 (file)
--- a/wpa_supplicant/wpas_kay.c
+++ b/wpa_supplicant/wpas_kay.c
@@ -357,8 +357,8 @@ void * ieee802_1x_notify_create_actor(struct wpa_supplicant *wpa_s,
 
        /* Derive CAK from MSK */
        cak->len = DEFAULT_KEY_LEN;
-       if (ieee802_1x_cak_128bits_aes_cmac(msk->key, wpa_s->own_addr,
-                                           peer_addr, cak->key)) {
+       if (ieee802_1x_cak_aes_cmac(msk->key, msk->len, wpa_s->own_addr,
+                                   peer_addr, cak->key, cak->len)) {
                wpa_printf(MSG_ERROR,
                           "IEEE 802.1X: Deriving CAK failed");
                goto fail;
@@ -367,9 +367,8 @@ void * ieee802_1x_notify_create_actor(struct wpa_supplicant *wpa_s,
 
        /* Derive CKN from MSK */
        ckn->len = DEFAULT_CKN_LEN;
-       if (ieee802_1x_ckn_128bits_aes_cmac(msk->key, wpa_s->own_addr,
-                                           peer_addr, sid, sid_len,
-                                           ckn->name)) {
+       if (ieee802_1x_ckn_aes_cmac(msk->key, msk->len, wpa_s->own_addr,
+                                   peer_addr, sid, sid_len, ckn->name)) {
                wpa_printf(MSG_ERROR,
                           "IEEE 802.1X: Deriving CKN failed");
                goto fail;