Merge pull request ARMmbed#25 from paul-szczepanek-arm/oob-gen

generate oob at will and without passing in connection handle

features/FEATURE_BLE/ble/BLETypes.h

@@ -261,6 +261,27 @@ class PasskeyAscii {
     uint8_t ascii[PASSKEY_LEN];
 };
 
+/**
+ * Returns true if every byte is equal to zero
+ */
+template <class byte_array_class>
+bool is_all_zeros(byte_array_class &byte_array) {
+    for (size_t i = 0; i < byte_array.size(); i++) {
+        if (byte_array[i] != 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
+/**
+ * Zero out all bytes
+ */
+template <class byte_array_class>
+void set_all_zeros(byte_array_class &byte_array) {
+    memset(&byte_array[0], 0x00, byte_array.size());
+}
+
 template <size_t array_size>
 struct byte_array_t {
     /**

features/FEATURE_BLE/ble/SecurityManager.h

@@ -735,15 +735,48 @@ class SecurityManager {
     // MITM
     //
 
+    /**
+     * Generate OOB data with the given address. If Secure Connections is supported this will
+     * also generate Secure Connections OOB data on top of legacy pairing OOB data. This can be used
+     * to generate such data before the connection takes place.
+     *
+     * In this model the OOB exchange takes place before the devices connect. Devices should establish
+     * communication over another channel and exchange the OOB data. The address provided will be used
+     * by the peer to associate the received data with the address of the device it will then connect
+     * to over BLE.
+     *
+     * @param[in] address The local address you will use in the connection using this OOB data. This
+     *                    address will be returned along with the rest of the OOB data when generation
+     *                    is complete. Using an invalid address is illegal.
+     * @return BLE_ERROR_NONE or appropriate error code indicating the failure reason.
+     */
+    virtual ble_error_t generateOOB(const ble::address_t *address) {
+        /* Avoid compiler warnings about unused variables */
+        (void) address;
+        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if security is supported. */
+    }
+
     /**
      * Enable OOB data usage during paring. If Secure Connections is supported enabling useOOB will
-     * generate Secure Connections OOB data through oobGenerated().
+     * generate Secure Connections OOB data through oobGenerated() on top of legacy pairing OOB data.
+     *
+     * You do not have to call this function to return received OOB data. Use legacyPairingOobReceived
+     * or oobReceived to hand it in. This will allow the stack to use it if possible. You only need to
+     * call this function to attempt legacy OOB data exchange after pairing start and to inform
+     * the stack OOB data does not provide MITM protection (by default it is set to provide this).
+     *
+     * In this model the OOB exchange takes places after the devices have connected but possibly
+     * prior to pairing. For secure connections pairing must not be started until after the OOB
+     * data has been sent and/or received. The address in the OOB data generated will match
+     * the original address used to establish the connection and will be used by the peer to
+     * identify which connection the OOB data belongs to.
      *
      * @param[in] connectionHandle Handle to identify the connection.
      * @param[in] useOOB If set to true, authenticate using OOB data.
      * @param[in] OOBProvidesMITM If set to true keys exchanged during pairing using OOB data
-     *                            will provide MITM protection. This indicates that the form
-     *                            of exchange used by the OOB data itself provides MITM protection.
+     *                            will provide Man-in-the-Middle protection. This indicates that
+     *                            the form of exchange used by the OOB data itself provides MITM
+     *                            protection.
      * @return BLE_ERROR_NONE or appropriate error code indicating the failure reason.
      */
     virtual ble_error_t setOOBDataUsage(ble::connection_handle_t connectionHandle, bool useOOB, bool OOBProvidesMITM = true) {

features/FEATURE_BLE/ble/generic/GenericSecurityManager.h

@@ -192,6 +192,10 @@ class GenericSecurityManager : public SecurityManager,
     // MITM
     //
 
+    virtual ble_error_t generateOOB(
+        const address_t *address
+    );
+
     virtual ble_error_t setOOBDataUsage(
         connection_handle_t connection,
         bool useOOB,
@@ -240,6 +244,11 @@ class GenericSecurityManager : public SecurityManager,
         _legacy_pairing_allowed(true),
         _master_sends_keys(false) {
         _pal.set_event_handler(this);
+
+        /* We create a fake value for oob to allow creation of the next oob which needs
+         * the last process to finish first before restarting (this is to simplify checking).
+         * This fake value will not be used as the oob address is currently invalid */
+        _oob_local_random[0] = 1;
     }
 
     ////////////////////////////////////////////////////////////////////////////
@@ -441,6 +450,7 @@ class GenericSecurityManager : public SecurityManager,
     pal::ConnectionEventMonitor &_connection_monitor;
 
     /* OOB data */
+    address_t _oob_local_address;
     address_t _oob_peer_address;
     oob_lesc_value_t _oob_peer_random;
     oob_confirm_t _oob_peer_confirm;
@@ -572,7 +582,6 @@ class GenericSecurityManager : public SecurityManager,
     /** @copydoc ble::pal::SecurityManager::on_secure_connections_oob_generated
      */
     virtual void on_secure_connections_oob_generated(
-        connection_handle_t connection,
         const oob_lesc_value_t &random,
         const oob_confirm_t &confirm
     );