forked from Green-Sky/tomato
Green Sky
227425b90e
git-subtree-dir: external/toxcore/c-toxcore git-subtree-split: 67badf69416a74e74f6d7eb51dd96f37282b8455
55 lines
2.3 KiB
Markdown
55 lines
2.3 KiB
Markdown
Encryption library used: http://nacl.cr.yp.to/
|
|
|
|
|
|
When running the program for the first time the crypto_box_keypair() function is used to
|
|
generate the users public-private key pair. (32 bytes each)
|
|
|
|
The generated public key is set as the client_id of the peer.
|
|
|
|
Adding a friend
|
|
---------------
|
|
|
|
Alice adds Bob to her friend list by adding his 32 byte public key (client_id) to her friend list.
|
|
2 cases:
|
|
case 1: Alice adds the public key of Bob, then Bob waits for Alice to attempt to connect to him.
|
|
case 2: Bob and Alice add their respective public keys to their friend lists at the same time.
|
|
|
|
case 1:
|
|
Alice sends an onion data (see: Prevent_tracking.txt) packet to Bob with the encrypted part containing the friend request like so:
|
|
```
|
|
[char with a value of 32][nospam number (4 bytes)][Message]
|
|
```
|
|
|
|
Ex message: hello Bob it's me Alice -_- add me pl0x.
|
|
|
|
For more info on the nospam see: Spam_Prevention.txt
|
|
|
|
Bob receives the request and decrypts the message using the function crypto_box_open()
|
|
|
|
If the message decrypts successfully:
|
|
If Alice is already in Bob's friend list: case 2
|
|
If Alice is not in Bob's friend list and the nospam is good: Bob is prompt to add Alice and is shown the message from her.
|
|
If Bob accepts Alice friend request he adds her public key to his friend list.
|
|
|
|
case 2:
|
|
Bob and Alice both have the others public key in their friend list, they are ready for the next step: Connecting to an already added friend
|
|
|
|
In the next step only crypto_box() is used for encryption and only crypto_box_open() for decryption (just like in the last step.)
|
|
|
|
|
|
Connecting to an already added friend
|
|
-------------------------------------
|
|
|
|
see: Tox_middle_level_network_protocol.txt
|
|
|
|
Crypto request packets
|
|
--------------------------------------
|
|
|
|
```
|
|
[char with a value of 32][Bob (The receiver's) Public key (client_id) (32 bytes))][Alice's (The sender's) Public key (client_id) (32 bytes)][Random nonce (24 bytes)][Encrypted message]
|
|
```
|
|
|
|
The encrypted message is encrypted with crypto_box() (using Bob's public key, Alice's private key and the nonce (randomly generated 24 bytes)) and is a message from Alice in which she tells Bob who she is.
|
|
|
|
Each node can route the request to the receiver if they are connected to him. This is to bypass bad NATs.
|