Added Pymesh Security content

config.toml

@@ -1252,8 +1252,8 @@ theme = "doc-theme"
 
 [[menu.main]]
     name = "Advanced Security Example"
-    url = "/pymesh/security-advanced"
-    identifier = "pymesh@security-advanced"
+    url = "/pymesh/security"
+    identifier = "pymesh@security"
     parent = "pymesh"
     weight = 50
 

content/pymesh/_index.md

@@ -29,4 +29,4 @@ Pymesh solution works on all of our LoRa supporting development boards, the LoPy
 * [Pymesh Micropython API](/firmwareapi/pycom/network/lora/pymesh)
 * [Simple Example](/pymesh/lora-mesh)
 * [Border Router Example](/pymesh/pymesh-br)
-* ​[Advanced Security Example](/pymesh/security-advanced)​
+* ​[Advanced Security Example](/pymesh/security)​

content/pymesh/library.md

@@ -8,15 +8,19 @@ aliases:
 
 Pymesh micropython library is a set of scripts included (as frozen) in the Pymesh firmware binary release (Not yet released).
 
+[Open-source on github](https://github.com/pycom/pycom-libraries/tree/master/lib/pymesh)
+
 It allows users to use Pymesh in a few lines of code, as shown in the following code snippet.
 
 ```python
+
 import pycom
 import time
 
 from _pymesh_config import PymeshConfig
 from _pymesh import Pymesh
 
+# stop LED heartbeat, because it will be used to indicate current Node role 
 pycom.heartbeat(False)
 
 # read config file, or set default values
@@ -42,4 +46,27 @@ def new_message_cb(rcv_ip, rcv_port, rcv_data):
     # ...
     return
 
+######################################################################################
+# Adding current node as Border Router, with a normal priority and a message handler callback
+pymesh.br_set(PymeshConfig.BR_PRIORITY_NORM, new_br_message_cb)
+
+# remove Border Router function from current node
+#pymesh.br_remove()
+
+# send data for Mesh-external, basically to the BR
+ip = "1:2:3::4"
+port = 5555
+pymesh.send_mess_external(ip, port, "Hello World")
+
+def new_br_message_cb(rcv_ip, rcv_port, rcv_data, dest_ip, dest_port):
+    ''' callback triggered when a new packet arrived for the current Border Router,
+    having destination an IP which is external from Mesh '''
+    print('Incoming %d bytes from %s (port %d), to external IPv6 %s (port %d)' %
+            (len(rcv_data), rcv_ip, rcv_port, dest_ip, dest_port))
+    print(rcv_data)
+
+    # user code to be inserted, to send packet to the designated Mesh-external interface
+    # ...
+    return
+
 ```

content/pymesh/security.md

@@ -0,0 +1,39 @@
+---
+title: "Pymesh Security"
+aliases:
+  - pymesh/security
+---
+
+Pymesh supports several levels of encryption.
+
+## Mesh Masterkey
+
+Each node (Lopy/Fipy) initializes Pymesh with a 128 bits Masterkey. This is used in:
+
+* authentication
+ * a Node which does not have the Masterkey of the peer, can't connect to peer's Pymesh;
+ * further, it will create its own Pymesh, using its Masterkey, so it will become the Leader of a new Mesh network.
+* encryption
+ * all traffic inside Pymesh is encrypted with Masterkey
+  * encryption is AES-128bits.
+
+## End to end encryption
+End to end encryption is used when Node A wants to communicate securely/secretly with Node B. The data packets will be routed by other nodes, but the actual message can't be decrypted by any middle Node.
+
+This encryption can be used even for communicating between Nodes that are not in the same mesh, as message is encrypted until destination. For example, in the next picture, Node A can communicate encrypted with Node C.
+
+The challenge is in distributing the keys used for encryption(decryption), this is
+
+![](../../.gitbook/assets/pymesh_security.png)
+
+### Symmetric encryption
+
+Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both encryption of plaintext and decryption of ciphertext. More info could be checked on [Symmetric-key algorithm](https://en.wikipedia.org/wiki/Symmetric-key_algorithm).
+
+A micropython example script can be seen [here](../../firmwareapi/pycom/aes.md) using AES 128, 192 or 256 bits keys (`crypto.AES` class).
+
+### Asymmetric encryption
+
+Public-key cryptography, or asymmetric cryptography, is a cryptographic system that uses pairs of keys: public keys which may be disseminated widely, and private keys which are known only to the owner. More info could be checked on [Public-key cryptography](https://en.wikipedia.org/wiki/Public-key_cryptography).
+
+A micropython example script can be seen [here](../../firmwareapi/micropython/ucrypto.md) using RSA 2048 bits keys (`crypto.rsa_encrypt()` method).