Cjdnsctrl - tool for parsing/serializing CTRL messages

Cjdns contains a set of low level messages which are not encrypted. If you send a packet and it cannot be forwarded, the switch which knows it is not possible to forward will notify you with a CTRL message, these are not encrypted because obviously the switch doesn't know who you are and can't reasonably encrypt anything to you.

CTRL messages include

• PING: request that the content of the message be echo'd back to you
• PONG: response to a PING message
• KEYPING: Similar to a ping except that the message also sends a public key and requests one back. NOTE: When constructing a keyping, remember that the key you send is your key and the other person's key should be in the response.
• KEYPONG: Response to a KEYPING message, contains the responder's key.
• ERROR: Emitted by the switch in case a message cannot be forwarded.

Types of error messages

• MALFORMED_ADDRESS: The switch label was malformed
• FLOOD: Packet dropped because link is congested (never sent as of v18)
• LINK_LIMIT_EXCEEDED: Packet dropped because node has oversent its limit (never sent as of v18)
• OVERSIZE_MESSAGE: Message too big to send, caused by differing MTU along a path
• UNDERSIZE_MESSAGE: Message smaller than expected headers
• AUTHENTICATION: Authentication failed (CryptoAuth could not understand the packet)
• INVALID: Header is invalid or checksum failed
• UNDELIVERABLE: Message could not be sent to its destination through no fault of the sender
• LOOP_ROUTE: The route enters and leaves through the same interface in one switch
• RETURN_PATH_INVALID: The switch is unable to represent the return path, this basically means the label is so long that the inverse label is impossible to put in 64 bits.

How to use:

input:

const Cjdnsctrl = require('cjdnsctrl');
Cjdnsctrl.parse(new Buffer(
    "994b00050123456700000012a331ebbed8d92ac03b10efed3e389cd0c6ec7331" +
    "a72dbde198476c5eb4d14a1f02e29842b42aedb6bce2ead3", "hex"));

result:

{ type: 'KEYPING',
  version: 18,
  key: '3fdqgz2vtqb0wx02hhvx3wjmjqktyt567fcuvj3m72vw5u6ubu740k3m22fplqvqwpspy93.k',
  content: <Buffer > }

input:

const Cjdnsctrl = require('cjdnsctrl');
Cjdnsctrl.serialize({
    type: 'KEYPING',
    version: 18,
    key: '3fdqgz2vtqb0wx02hhvx3wjmjqktyt567fcuvj3m72vw5u6ubu740k3m22fplqvqwpspy93.k',
    content: new Buffer(0)
});

result:

<Buffer 99 4b 00 05 01 23 45 67 00 00 00 12 a3 31 eb be d8 d9 2a c0 3b 10 ef ed 3e 38 9c ... >