minor fixups to get nrf52 building again

docs/README.md

@@ -1,7 +1,7 @@
 # What is Meshtastic?
 
 Meshtastic is a project that lets you use
-inexpensive (\$30 ish) GPS radios as an extensible, super long battery life mesh GPS communicator. These radios are great for hiking, skiing, paragliding - essentially any hobby where you don't have reliable internet access. Each member of your private mesh can always see the location and distance of all other members and any text messages sent to your group chat.
+inexpensive (\$30 ish) GPS radios as an extensible, long battery life, secure, mesh GPS communicator. These radios are great for hiking, skiing, paragliding - essentially any hobby where you don't have reliable internet access. Each member of your private mesh can always see the location and distance of all other members and any text messages sent to your group chat.
 
 The radios automatically create a mesh to forward packets as needed, so everyone in the group can receive messages from even the furthest member. The radios will optionally work with your phone, but no phone is required.
 

docs/software/crypto.md

@@ -4,8 +4,8 @@ Cryptography is tricky, so we've tried to 'simply' apply standard crypto solutio
 the project developers are not cryptography experts. Therefore we ask two things:
 
 - If you are a cryptography expert, please review these notes and our questions below. Can you help us by reviewing our
-  notes below and offering advice? We will happily give as much or as little credit as you wish as our thanks ;-).
-- Consider our existing solution 'alpha' and probably fairly secure against an not very aggressive adversary. But until
+  notes below and offering advice? We will happily give as much or as little credit as you wish ;-).
+- Consider our existing solution 'alpha' and probably fairly secure against a not particularly aggressive adversary. But until
   it is reviewed by someone smarter than us, assume it might have flaws.
 
 ## Notes on implementation
@@ -16,7 +16,7 @@ the project developers are not cryptography experts. Therefore we ask two things
 
 Parameters for our CTR implementation:
 
-- Our AES key is 256 bits, shared as part of the 'Channel' specification.
+- Our AES key is 128 or 256 bits, shared as part of the 'Channel' specification.
 - Each SubPacket will be sent as a series of 16 byte BLOCKS.
 - The node number concatenated with the packet number is used as the NONCE. This counter will be stored in flash in the device and should essentially never repeat. If the user makes a new 'Channel' (i.e. picking a new random 256 bit key), the packet number will start at zero. The packet number is sent
   in cleartext with each packet. The node number can be derived from the "from" field of each packet.
@@ -35,4 +35,6 @@ Note that for both stategies, sizes are measured in blocks and that an AES block
 ## Remaining todo
 
 - Make the packet numbers 32 bit
+- Confirm the packet #s are stored in flash across deep sleep (and otherwise in in RAM)
+- Have the app change the crypto key when the user generates a new channel
 - Implement for NRF52 [NRF52](https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.0.0/lib_crypto_aes.html#sub_aes_ctr)

src/mesh/FloodingRouter.cpp

@@ -116,7 +116,7 @@ bool FloodingRouter::wasSeenRecently(const MeshPacket *p)
     }
 
     uint32_t now = millis();
-    for (int i = 0; i < recentBroadcasts.size();) {
+    for (size_t i = 0; i < recentBroadcasts.size();) {
         BroadcastRecord &r = recentBroadcasts[i];
 
         if ((now - r.rxTimeMsec) >= FLOOD_EXPIRE_TIME) {

src/mesh/RadioLibInterface.cpp

@@ -197,6 +197,9 @@ void RadioLibInterface::loop()
 
 #ifndef NO_ESP32
 #define USE_HW_TIMER
+#else
+// Not needed on NRF52
+#define IRAM_ATTR
 #endif
 
 void IRAM_ATTR RadioLibInterface::timerCallback(void *p1, uint32_t p2)

src/mesh/StreamAPI.cpp

@@ -31,7 +31,7 @@ void StreamAPI::readStream()
             if (c != START2)
                 rxPtr = 0;                             // failed to find framing
         } else if (ptr >= HEADER_LEN) {                // we have at least read our 4 byte framing
-            uint16_t len = (rxBuf[2] << 8) + rxBuf[3]; // big endian 16 bit length follows framing
+            uint32_t len = (rxBuf[2] << 8) + rxBuf[3]; // big endian 16 bit length follows framing
 
             if (ptr == HEADER_LEN) {
                 // we _just_ finished our 4 byte header, validate length now (note: a length of zero is a valid

src/nrf52/NRF52CryptoEngine.cpp

@@ -0,0 +1,5 @@
+
+#include "CryptoEngine.h"
+
+// FIXME, do a NRF52 version
+CryptoEngine *crypto = new CryptoEngine();