EAP-FAST: Check T-PRF result in MSK/EMSK derivation

Pass the error return from sha1_t_prf() to callers.

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

diff --git a/src/eap_common/eap_fast_common.c b/src/eap_common/eap_fast_common.c
index 151cc7859c5da8cf8e9972930da992530d382707..e8587fdaac03a6039608d6629cbb2ee9a9d97906 100644 (file)
--- a/src/eap_common/eap_fast_common.c
+++ b/src/eap_common/eap_fast_common.c
@@ -111,22 +111,24 @@ u8 * eap_fast_derive_key(void *ssl_ctx, struct tls_connection *conn,
 }
 
 
-void eap_fast_derive_eap_msk(const u8 *simck, u8 *msk)
+int eap_fast_derive_eap_msk(const u8 *simck, u8 *msk)
 {
        /*
         * RFC 4851, Section 5.4: EAP Master Session Key Generation
         * MSK = T-PRF(S-IMCK[j], "Session Key Generating Function", 64)
         */
 
-       sha1_t_prf(simck, EAP_FAST_SIMCK_LEN,
-                  "Session Key Generating Function", (u8 *) "", 0,
-                  msk, EAP_FAST_KEY_LEN);
+       if (sha1_t_prf(simck, EAP_FAST_SIMCK_LEN,
+                      "Session Key Generating Function", (u8 *) "", 0,
+                      msk, EAP_FAST_KEY_LEN) < 0)
+               return -1;
        wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Derived key (MSK)",
                        msk, EAP_FAST_KEY_LEN);
+       return 0;
 }
 
 
-void eap_fast_derive_eap_emsk(const u8 *simck, u8 *emsk)
+int eap_fast_derive_eap_emsk(const u8 *simck, u8 *emsk)
 {
        /*
         * RFC 4851, Section 5.4: EAP Master Session Key Genreration
@@ -134,11 +136,13 @@ void eap_fast_derive_eap_emsk(const u8 *simck, u8 *emsk)
         *        "Extended Session Key Generating Function", 64)
         */
 
-       sha1_t_prf(simck, EAP_FAST_SIMCK_LEN,
-                  "Extended Session Key Generating Function", (u8 *) "", 0,
-                  emsk, EAP_EMSK_LEN);
+       if (sha1_t_prf(simck, EAP_FAST_SIMCK_LEN,
+                      "Extended Session Key Generating Function", (u8 *) "", 0,
+                      emsk, EAP_EMSK_LEN) < 0)
+               return -1;
        wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Derived key (EMSK)",
                        emsk, EAP_EMSK_LEN);
+       return 0;
 }
 
 

diff --git a/src/eap_common/eap_fast_common.h b/src/eap_common/eap_fast_common.h
index d59a8450ba8c7606c9aedab9d473f6234ae1b038..6756dd23fc8f4c042b8e83ba064331d8407a24fa 100644 (file)
--- a/src/eap_common/eap_fast_common.h
+++ b/src/eap_common/eap_fast_common.h
@@ -99,8 +99,8 @@ void eap_fast_derive_master_secret(const u8 *pac_key, const u8 *server_random,
                                   const u8 *client_random, u8 *master_secret);
 u8 * eap_fast_derive_key(void *ssl_ctx, struct tls_connection *conn,
                         const char *label, size_t len);
-void eap_fast_derive_eap_msk(const u8 *simck, u8 *msk);
-void eap_fast_derive_eap_emsk(const u8 *simck, u8 *emsk);
+int eap_fast_derive_eap_msk(const u8 *simck, u8 *msk);
+int eap_fast_derive_eap_emsk(const u8 *simck, u8 *emsk);
 int eap_fast_parse_tlv(struct eap_fast_tlv_parse *tlv,
                       int tlv_type, u8 *pos, size_t len);
 

diff --git a/src/eap_peer/eap_fast.c b/src/eap_peer/eap_fast.c
index 6e8b12fd651130fc2931c5009ba8417e70e41b78..8b6b7fd929a9a22b6f7130a7b36b5e1f47bcab18 100644 (file)
--- a/src/eap_peer/eap_fast.c
+++ b/src/eap_peer/eap_fast.c
@@ -260,8 +260,9 @@ static void eap_fast_deinit(struct eap_sm *sm, void *priv)
 
 static int eap_fast_derive_msk(struct eap_fast_data *data)
 {
-       eap_fast_derive_eap_msk(data->simck, data->key_data);
-       eap_fast_derive_eap_emsk(data->simck, data->emsk);
+       if (eap_fast_derive_eap_msk(data->simck, data->key_data) < 0 ||
+           eap_fast_derive_eap_emsk(data->simck, data->emsk) < 0)
+               return -1;
        data->success = 1;
        return 0;
 }

diff --git a/src/eap_server/eap_server_fast.c b/src/eap_server/eap_server_fast.c
index 47210e14889b5d2558f111b2794dc915b9c5e3ba..e348eb3e2559962e62fdf9e68bf397971e272fbd 100644 (file)
--- a/src/eap_server/eap_server_fast.c
+++ b/src/eap_server/eap_server_fast.c
@@ -1564,7 +1564,10 @@ static u8 * eap_fast_getKey(struct eap_sm *sm, void *priv, size_t *len)
        if (eapKeyData == NULL)
                return NULL;
 
-       eap_fast_derive_eap_msk(data->simck, eapKeyData);
+       if (eap_fast_derive_eap_msk(data->simck, eapKeyData) < 0) {
+               os_free(eapKeyData);
+               return NULL;
+       }
        *len = EAP_FAST_KEY_LEN;
 
        return eapKeyData;
@@ -1583,7 +1586,10 @@ static u8 * eap_fast_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
        if (eapKeyData == NULL)
                return NULL;
 
-       eap_fast_derive_eap_emsk(data->simck, eapKeyData);
+       if (eap_fast_derive_eap_emsk(data->simck, eapKeyData) < 0) {
+               os_free(eapKeyData);
+               return NULL;
+       }
        *len = EAP_EMSK_LEN;
 
        return eapKeyData;