Revamp the simple password flag and rPi fixes (#1056)

MY_SIGNING_SIMPLE_PASSWD is now
called MY_SECURITY_SIMPLE_PASSWD.
MY_SIGNING_SIMPLE_PASSWD only affects signing,
and a new flag, MY_ENCRYPTION_SIMPLE_PASSWD
only affects encryption.
MY_SECURITY_SIMPLE_PASSWD enable both these flags.

The rPi port has been improved to support more
security settings and it is now also possible to
enable encryption for RFM69 transport.

Documentation has been improved to provide a
"Security" section under "Library customisation"
which has a table that summarize all security
related configuration flags, and the corresponding
rPi configuration flags.

The signing personalization documentation has been
updated to include the procedure for rPi.

Fixes #1055

configure

@@ -72,7 +72,7 @@ MySensors options:
     --my-rf24-encryption-enabled
                                 Enables RF24 encryption.
                                 All nodes and gateway must have this enabled, and all must be
-                                personalized with the same AES key
+                                personalized with the same AES key.
     --my-rx-message-buffer-size=<SIZE>
                                 Buffer size for incoming messages when using rf24 interrupts. [20]
     --my-rfm69-frequency=[315|433|868|915]
@@ -80,6 +80,10 @@ MySensors options:
     --my-is-rfm69hw             Enable high-powered rfm69hw.
     --my-rfm69-irq-pin=<PIN>    Pin number connected to RFM69 IRQ pin.
     --my-rfm69-cs-pin=<PIN>     Pin number to use for RFM69 Chip-Select.
+    --my-rfm69-encryption-enabled
+                                Enables RFM69 encryption.
+                                All nodes and gateway must have this enabled, and all must be
+                                personalized with the same AES key.
     --my-rs485-serial-port=<PORT>
                                 RS485 serial port. You must provide a port.
     --my-rs485-baudrate=<BAUD>  RS485 baudrate. [9600]
@@ -98,8 +102,13 @@ MySensors options:
                                 gateway signature.
     --my-signing-weak_security  Enable this to permit downgrade of security preferences and
                                 relaxed gateway signing requirements.
-    --my-signing-password=<PASSWORD>
-                                If you are using password as the signature type, set your password here.
+    --my-signing-whitelist=<WHITELIST>
+                                If you want to use a whitelist, provide it here, make sure to avoid
+                                spaces in the <whitelist> expression.
+    --my-signing-verification-timeout-ms=<TIMEOUT>
+                                Signing timeout. [5000]
+    --my-security-password=<PASSWORD>
+                                If you are using password for signing/encryption, set your password here.
 EOF
 }
 
@@ -258,6 +267,7 @@ gateway_type=ethernet
 transport_type=nrf24
 signing=none
 signing_request_signatures=false
+encryption=false
 
 params="SOC CFLAGS CXXFLAGS CPPFLAGS LDFLAGS PREFIX CC CXX ARDUINO_LIB_DIR BUILDDIR BINDIR GATEWAY_DIR INIT_SYSTEM SPI_DRIVER"
 
@@ -398,6 +408,7 @@ for opt do
         CPPFLAGS="-DMY_RX_MESSAGE_BUFFER_FEATURE -DMY_RF24_IRQ_PIN=${optarg} $CPPFLAGS"
         ;;
     --my-rf24-encryption-enabled*)
+        encryption=true
         CPPFLAGS="-DMY_RF24_ENABLE_ENCRYPTION $CPPFLAGS"
         ;;
     --my-rx-message-buffer-size=*)
@@ -425,6 +436,10 @@ for opt do
     --my-rfm69-cs-pin=*)
         CPPFLAGS="-DMY_RFM69_CS_PIN=${optarg} $CPPFLAGS"
         ;;
+    --my-rfm69-encryption-enabled*)
+        encryption=true
+        CPPFLAGS="-DMY_RFM69_ENABLE_ENCRYPTION $CPPFLAGS"
+        ;;
     --my-rs485-serial-port=*)
         CPPFLAGS="-DMY_RS485_HWSERIAL=\\\"${optarg}\\\" $CPPFLAGS"
         ;;
@@ -461,8 +476,14 @@ for opt do
     --my-signing-weak_security*)
         CPPFLAGS="-DMY_SIGNING_WEAK_SECURITY $CPPFLAGS"
         ;;
-    --my-signing-password=*)
-        signing_password=${optarg}
+    --my-signing-whitelist*)
+        CPPFLAGS="-DMY_SIGNING_NODE_WHITELISTING=${optarg} $CPPFLAGS"
+        ;;
+    --my-signing-verification-timeout-ms*)
+        CPPFLAGS="-DMY_VERIFICATION_TIMEOUT_MS=${optarg} $CPPFLAGS"
+        ;;
+    --my-security-password=*)
+        security_password=${optarg}
         ;;
     *)
         echo "[WARNING] Unknown option detected:$opt, ignored"
@@ -573,15 +594,25 @@ elif [[ ${signing} == "software" ]]; then
         CPPFLAGS="-DMY_SIGNING_REQUEST_SIGNATURES $CPPFLAGS"
     fi
 elif [[ ${signing} == "password" ]]; then
-    if [ -z "${signing_password}" ]; then
-        die "You need to set the password for signing with --my-signing-password= option" 6
+    if [ -z "${security_password}" ]; then
+        die "You need to set the password for signing with --my-security-password= option" 6
     fi
     echo "Simplified signing using password"
-    CPPFLAGS="-DMY_SIGNING_SIMPLE_PASSWD=\\\"${signing_password}\\\" $CPPFLAGS"
+    CPPFLAGS="-DMY_SIGNING_SIMPLE_PASSWD=\\\"${security_password}\\\" $CPPFLAGS"
 else
     die "Invalid signing type." 7
 fi
 
+if [[ ${encryption} == true ]]; then
+    # Encryption enabled on some transport
+    if [ -z "${security_password}" ]; then
+        echo "Encryption key from configuration"
+    else
+        echo "Simplified encryption using password"
+        CPPFLAGS="-DMY_ENCRYPTION_SIMPLE_PASSWD=\\\"${security_password}\\\" $CPPFLAGS"
+    fi
+fi
+
 LDFLAGS="-pthread $LDFLAGS"
 CPPFLAGS="$CPUFLAGS $CPPFLAGS"