mesh: Handle invalid public keys

Check for invalid public keys received and send provision failed.

Change-Id: Ie1a62b525560b367729c8f96b95669ffb34b70b1
Signed-off-by: Anupam Roy <anupam.r@samsung.com>

diff --git a/mesh/prov-acceptor.c b/mesh/prov-acceptor.c
index 03972c2..d395bc5 100644 (file)
--- a/mesh/prov-acceptor.c
+++ b/mesh/prov-acceptor.c
@@ -180,7 +180,7 @@ static void swap_u256_bytes(uint8_t *u256)
        }
 }
 
-static void prov_calc_secret(const uint8_t *pub, const uint8_t *priv,
+static bool prov_calc_secret(const uint8_t *pub, const uint8_t *priv,
                                                        uint8_t *secret)
 {
        uint8_t tmp[64];
@@ -190,22 +190,27 @@ static void prov_calc_secret(const uint8_t *pub, const uint8_t *priv,
        swap_u256_bytes(tmp);
        swap_u256_bytes(tmp + 32);
 
-       ecdh_shared_secret(tmp, priv, secret);
+       if (!ecdh_shared_secret(tmp, priv, secret))
+               return false;
 
        /* Convert to Mesh byte order */
        swap_u256_bytes(secret);
+       return true;
 }
 
-static void acp_credentials(struct mesh_prov_acceptor *prov)
+static bool acp_credentials(struct mesh_prov_acceptor *prov)
 {
-       prov_calc_secret(prov->conf_inputs.prv_pub_key,
-                       prov->private_key, prov->secret);
+       if (!prov_calc_secret(prov->conf_inputs.prv_pub_key,
+                       prov->private_key, prov->secret))
+               return false;
 
-       mesh_crypto_s1(&prov->conf_inputs,
-                       sizeof(prov->conf_inputs), prov->salt);
+       if (!mesh_crypto_s1(&prov->conf_inputs,
+                       sizeof(prov->conf_inputs), prov->salt))
+               return false;
 
-       mesh_crypto_prov_conf_key(prov->secret, prov->salt,
-                       prov->calc_key);
+       if (!mesh_crypto_prov_conf_key(prov->secret, prov->salt,
+                       prov->calc_key))
+               return false;
 
        l_getrandom(prov->rand_auth_workspace, 16);
 
@@ -218,6 +223,7 @@ static void acp_credentials(struct mesh_prov_acceptor *prov)
        print_packet("LocalRandom", prov->rand_auth_workspace, 16);
        print_packet("ConfirmationSalt", prov->salt, 16);
        print_packet("ConfirmationKey", prov->calc_key, 16);
+       return true;
 }
 
 static uint32_t digit_mod(uint8_t power)
@@ -298,8 +304,13 @@ static void priv_key_cb(void *user_data, int err, uint8_t *key, uint32_t len)
        swap_u256_bytes(prov->conf_inputs.dev_pub_key + 32);
 
        prov->material |= MAT_LOCAL_PRIVATE;
-       if ((prov->material & MAT_SECRET) == MAT_SECRET)
-               acp_credentials(prov);
+       if ((prov->material & MAT_SECRET) == MAT_SECRET) {
+               if (!acp_credentials(prov)) {
+                       msg.opcode = PROV_FAILED;
+                       msg.reason = PROV_ERR_UNEXPECTED_ERR;
+                       prov->trans_tx(prov->trans_data, &msg, sizeof(msg));
+               }
+       }
 }
 
 static void send_caps(struct mesh_prov_acceptor *prov)
@@ -423,7 +434,10 @@ static void acp_prov_rx(void *user_data, const uint8_t *data, uint16_t len)
                if ((prov->material & MAT_SECRET) != MAT_SECRET)
                        return;
 
-               acp_credentials(prov);
+               if (!acp_credentials(prov)) {
+                       fail.reason = PROV_ERR_UNEXPECTED_ERR;
+                       goto failure;
+               }
 
                if (!prov->conf_inputs.start.pub_key)
                        send_pub_key(prov);