Major documentation improvements (ntop#752)

Author: hamishcoleman

doc/Authentication.md

@@ -8,7 +8,7 @@ n2n implements two different authentication schemes the user can chose from.
 
 ### Identity Based Scheme
 
-A very basic authentication scheme based on a uniqe identification number is put in place. This ID is randomly generated during edge start-up and remains unchanged until the edge terminates. With every REGISTER_SUPER, it is tranmitted to the supernode which remembers it from the first REGISTER_SUPER and can compare it to all the following ones. It is a verfication based on "showing the ID". The supernode accepts REGISTER_SUPER (and thus changed MAC address or internet socket) and UNREGISTER type messages only if verification passes.
+A very basic authentication scheme based on a unique identification number is put in place. This ID is randomly generated during edge start-up and remains unchanged until the edge terminates. With every REGISTER_SUPER, it is transmitted to the supernode which remembers it from the first REGISTER_SUPER and can compare it to all the following ones. It is a verification based on "showing the ID". The supernode accepts REGISTER_SUPER (and thus changed MAC address or internet socket) and UNREGISTER type messages only if verification passes.
 
 This does not only prevent UNREGISTER attacks but also MAC spoofing even in case of several federated supernodes because each REGISTER_SUPER message is forwarded to all other supernodes. If a new edge (un)intentionally tries to claim a MAC address which already has been in use by another edge, this would be detected as unauthorized MAC change because the new edge presents a different authentication ID. The supernode which rejects it (based on a failed comparison) sends a REGISTER_SUPER_**NAK** type message to the new edge as well as the supernode through which the new edge tried to register. The REGISTER_SUPER_NAK will cause the edge to output an ERROR message, it does not stop the edge anymore to prevent de-auth attacks.
 
@@ -55,18 +55,18 @@ ntop[0-1][0-9]
 
 This example also lists another user `sister` (with the same secret password `007`). The users become part of the preceding community name, `netleo` in this case. The public keys are cryptographically tied only to the user name, not to the community name. That way, to switch a user from one community to another, her line can easily be copied from one community section to another. By the way, do not forget to provide the `community.list` file to the supernode through the `-c community.list` parameter.
 
-Current supernode behavior does not limit the simultanious usage of usernames, i.e. one username can be used from several edges at the same time. However, it is recommended to use a distinct username and password for each edge or computer. Your management port output will be much more meaningful then with the `HINT` column showing the related username. Also, the auto IP address feature, i.e. not using `-a <IP address>` at the edge, will more likely assign unique addresses as those depend on the username.
+Current supernode behavior does not limit the simultaneous usage of usernames, i.e. one username can be used from several edges at the same time. However, it is recommended to use a distinct username and password for each edge or computer. Your management port output will be much more meaningful then with the `HINT` column showing the related username. Also, the auto IP address feature, i.e. not using `-a <IP address>` at the edge, will more likely assign unique addresses as those depend on the username.
 
 If a user chooses a new password or needs to be excluded from accessing the community (stolen edge scenario), the corresponding line of the `community.list` file can be replaced with a newly generated one or be deleted respectively. Restarting the supernode or issuing the `reload_communities` command to the management port is required after performing changes to make the supernode(s) read in this data again.
 
 When using this feature federation-wide, i.e. across several supernodes, please make sure to keep all supernodes' `community.list` files in sync. So, if you delete or change a user one supernode (or add it), you need to do it at all supernodes. There is no built-in sync for the `community.list` files across the federation. External tools such as _Syncthing_ or your very own script-driven scp-based-file-distribution might be of assistance. Also, with every change, you need to restart the supernode or issue the `reload_communites` command to the management port as outlined above.
 
-With a view to the detailed explanations below, your supernode(s) should have a non-default federation name given by the `-F <federation name>` command line parameter, e.g. `-F secretFed`. It is used to derive a priavte key at the supernode side and is only to be shared among supernodes.
+With a view to the detailed explanations below, your supernode(s) should have a non-default federation name given by the `-F <federation name>` command line parameter, e.g. `-F secretFed`. It is used to derive a private key at the supernode side and is only to be shared among supernodes.
 
 
 #### Edge
 
-The edge takes the username with the already present, identifying command line paramater `-I <username>`. The password goes into `-J <password>`. Continuing the given example, the edge is invoked by
+The edge takes the username with the already present, identifying command line parameter `-I <username>`. The password goes into `-J <password>`. Continuing the given example, the edge is invoked by
 
 ```
 [user@host n2n]$ sudo ./edge -l <supernode:port> -c netleo -I logan -J 007 <your additional parameters>
@@ -87,19 +87,19 @@ Considering all this, our example expands to
 [user@host n2n]$ sudo ./edge -l <supernode:port> -c netleo -I logan -J 007 -A5 -k mySecretKey -P opIyaWhWjKLJSNOHNpKnGmelhHWRqkmY5pAx7lbDHp4
 ```
 
-You might want to consider the use of [`.conf` files](https://github.com/ntop/n2n/blob/dev/doc/ConfigurationFiles.md) to accomodate all the command line paramters more easily.
+You might want to consider the use of [`.conf` files](https://github.com/ntop/n2n/blob/dev/doc/ConfigurationFiles.md) to accomodate all the command line parameters more easily.
 
 
 #### How Does It Work?
 
-In order to make this authentication scheme work, the existing header encryption scheme is split into using two keys: a _static_ and a _dynamic_ one. The static key remains unchanged and is the [classic header encryption key](https://github.com/ntop/n2n/blob/dev/doc/Crypto.md#header) derived from the community name. It only is applied to the very basic registration traffic between edge and supernode (REGISTER_SUPER, REGISTER_SUPER_ACK, REGISTER_SUPER_NAK). The dynamic key is derived (among others) from the federation name – keep it secret! – and appplied to all the other packets, especially the data packets (PAKET) and peer-to-peer building packets (REGISTER), but also the ping and peer information (QUERY_PEER, PEER_INFO). An edge not provided with a valid dynamic key is not able to participate in the further communication.
+In order to make this authentication scheme work, the existing header encryption scheme is split into using two keys: a _static_ and a _dynamic_ one. The static key remains unchanged and is the [classic header encryption key](https://github.com/ntop/n2n/blob/dev/doc/Crypto.md#header) derived from the community name. It only is applied to the very basic registration traffic between edge and supernode (REGISTER_SUPER, REGISTER_SUPER_ACK, REGISTER_SUPER_NAK). The dynamic key is derived (among others) from the federation name – keep it secret! – and applied to all the other packets, especially the data packets (PACKET) and peer-to-peer building packets (REGISTER), but also the ping and peer information (QUERY_PEER, PEER_INFO). An edge not provided with a valid dynamic key is not able to participate in the further communication.
 
-In regular header encryption mode, static key and dynamic key are equal. With activated user-password scheme, the supernode generates and transmits a dynamic key with the REGISTER_SUPER for further use. This happens in a secure way based on public key cryptography. A non-autheticated edge, i.e. without corresponding entry at the supernode or valid credentials, will not receive a valid dynmic key for communication beyond registration.
+In regular header encryption mode, static key and dynamic key are equal. With activated user-password scheme, the supernode generates and transmits a dynamic key with the REGISTER_SUPER for further use. This happens in a secure way based on public key cryptography. A non-authenticated edge, i.e. without corresponding entry at the supernode or valid credentials, will not receive a valid dynmic key for communication beyond registration.
 
 In user-password scheme, the packets encrypted with the static key (REGISTER_SUPER, REGISTER_SUPER_ACK, useless for REGISTER_SUPER_NAK) are "signed" with an encrypted outer hash using the shared secret which is only known to the federated supernodes and that specific edge.
 
 #### Possible Extensions
 
 Tools for automizing [`.conf` file](https://github.com/ntop/n2n/blob/dev/doc/ConfigurationFiles.md) generation for deployment ot delivery to freshly registered and approved users could greatly enhance this ecosystem; a user would not have to mess around with command line parameters but just copy a `.conf` file into a specified directory.
 
-Let us know if you are intrerested in implementing or furthering these ideas.
+Let us know if you are interested in implementing or furthering these ideas.

doc/Communities.md

@@ -3,7 +3,7 @@
 
 ## Names
 
-As communities designate virtual networks, they must be distingushable from each other. Its their name that makes them distinguishable and which therefore should be unique per network. The community name is composed of 19 byte-sized characters and it internally always is terminated by an additional zero character totalling up to 20 characters. Hence, the zero character cannot be part of the regular community name. There are some other characters that cannot be used, namely `. * + ? [ ] \`.
+As communities designate virtual networks, they must be distinguishable from each other. Its their name that makes them distinguishable and which therefore should be unique per network. The community name is composed of 19 byte-sized characters and it internally always is terminated by an additional zero character totalling up to 20 characters. Hence, the zero character cannot be part of the regular community name. There are some other characters that cannot be used, namely `. * + ? [ ] \`.
 
 To make full use of character space, hex values could be used, e.g. from Linux bash applying the `edge … -c $(echo -en '\x3a\x3b\x4a\x6a\xfa') …` command line syntax. If used with a configuration file, the bytes must be directly filled as characters into a corresponding `-c :;Jjþ` line.
 
@@ -65,7 +65,7 @@ Also, as the `. * + ? [ ] \` characters indicate parts of regular expressions, w
 
 By default, the community name is transmitted in plain witch each packet. So, a fixed-name community might keep your younger siblings out of your community (as long as they do not know the community name) but sniffing attackers will find out the community name. Using this name, they will be able to access it by just connecting to the supernode then.
 
-[Header encryption](Crypto.md#header) can be enabled to prevent plain transmission. It is important to understand that header encryption, if enabled, only works on fixed-name communities. It will not work on communitiy names described by regular expressions.
+[Header encryption](Crypto.md#header) can be enabled to prevent plain transmission. It is important to understand that header encryption, if enabled, only works on fixed-name communities. It will not work on community names described by regular expressions.
 
 On the other hand, the provision of fixed-name communities blocks all other, non-listed communities. To allow a mixed operation of certain encrypted and hence fixed-name communities along with all other open communities, the following "trick" can be applied:
 

doc/ConfigurationFiles.md

@@ -70,4 +70,4 @@ Finally, the `.conf` file syntax also allows `=` between parameter and its optio
 -l=supernode.ntop.org:7777
 ```
 
-When used with `=`, there is no whitespace allowed between parameter, delimter (`=`), and option. So, do **not** put `-c = mynetwork` – it is required to be `-c=mynetwork`.
+When used with `=`, there is no whitespace allowed between parameter, delimiter (`=`), and option. So, do **not** put `-c = mynetwork` – it is required to be `-c=mynetwork`.