62 lines
2.1 KiB
Go
62 lines
2.1 KiB
Go
package shared
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import "encoding/binary"
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const PROTO_VERSION uint16 = 1
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// pubKey - public key generated by the client
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// privKey - private key generated by the client
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// sessionKey - key established between two peers
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// multicastKey - key shared between everyone for encrypting multicast pkts
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// authSecret - secret given during registration for authenticating subsequent requests
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const (
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_ uint16 = iota
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// (client -> server) requests a challenge to prove the ownership of the privKey
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// [ pubKey - 1216 bytes ]
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REQ_GET_CHALLENGE
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// (server -> client) provides a pubKey-encrypted authSecret
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// [ ciphertext - 1168 bytes ]
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RESP_GET_CHALLENGE
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// (client -> server) requests an IP
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// [ HMAC(authSecret, pubKey) - 32 bytes ] [ pubKey - 1216 bytes ]
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REQ_REGISTER
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// (server -> client) returns the assigned IP and pubKey-encrypted multicastKey
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// [ ip - 16 bytes ] [ ciphertext - 1168 bytes ]
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RESP_REGISTER
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// (client -> server -> client2) relays an encrypted packet to a specified peer
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// [ HMAC(authSecret, rest) - 32 bytes ] [ destIP - 16 bytes ] [ srcIP - 16 bytes ] [ encryptedPkt ]
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ENC_PKT
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// (client -> server -> *) broadcasts an encrypted packet
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// [ HMAC(authSecret, rest) - 32 bytes ] [ encryptedPkt ]
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BROADCAST_PKT
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// (client -> server) requests peer's pubKey from the server for encapsulation
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// [ ip - 16 bytes ]
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REQ_GET_PUBKEY
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// (server -> client) provides requested pubKey
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// [ ip - 16 bytes ] [ pubKey - 1216 bytes ]
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RESP_GET_PUBKEY
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// (client -> server -> client2) establishes a sessionKey with another peer
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// [ HMAC(authSecret, rest) - 32 bytes ] [ destIP - 16 bytes ] [ srcIP - 16 bytes ] [ ciphertext - 1120 bytes ]
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REQ_ESTABLISH
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// (client2 -> server -> client) acknowledges the sessionKey was established
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// [ HMAC(authSecret, rest) - 32 bytes ] [ destIP - 16 bytes ] [ srcIP - 16 bytes ]
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RESP_ESTABLISH
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)
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func BuildPkt(pktType uint16, parts ...[]byte) []byte {
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var total int
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for _, p := range parts {
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total += len(p)
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}
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out := make([]byte, 4, 4+total)
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binary.LittleEndian.PutUint16(out[0:], PROTO_VERSION)
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binary.LittleEndian.PutUint16(out[2:], pktType)
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for _, p := range parts {
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out = append(out, p...)
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}
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return out
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}
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