Go_I2p/lib/common/lease.go

package common

/*
I2P Lease
https://geti2p.net/spec/common-structures#lease
Accurate for version 0.9.24

+----+----+----+----+----+----+----+----+
| tunnel_gw                             |
+                                       +
|                                       |
+                                       +
|                                       |
+                                       +
|                                       |
+----+----+----+----+----+----+----+----+
|     tunnel_id     |      end_date
+----+----+----+----+----+----+----+----+
                    |
+----+----+----+----+

tunnel_gw :: Hash of the RouterIdentity of the tunnel gateway
             length -> 32 bytes

tunnel_id :: TunnelId
             length -> 4 bytes

end_date :: Date
            length -> 8 bytes
*/

// Sizes or various components of a Lease
const (
	LEASE_SIZE             = 44
	LEASE_HASH_SIZE        = 32
	LEASE_TUNNEL_ID_SIZE   = 4
	LEASE_TUNNEL_DATE_SIZE = 8
)

type Lease struct {
	LeaseHash   [LEASE_HASH_SIZE]byte
	TunnelIdent [LEASE_TUNNEL_ID_SIZE]byte
	TunnelDate  [LEASE_TUNNEL_DATE_SIZE]byte
}

//[LEASE_SIZE]byte

//
// Return the first 32 bytes of the Lease as a Hash.
//
func (lease Lease) TunnelGateway() (hash Hash) {
	copy(hash[:], lease.LeaseHash[:])
	return
}

//
// Parse the TunnelID Integer in the Lease.
//
func (lease Lease) TunnelID() uint32 {
	return uint32(Integer(lease.TunnelIdent[:]))
}

//
// Return the Date inside the Lease.
//
func (lease Lease) Date() (date Date) {
	copy(date[:], lease.TunnelDate[:])
	return
}

//
// Possibly temporary? Just to make it compile for now
//
func (lease Lease) Bytes() (bytes []byte) {
	var r []byte
	r = append(r, lease.LeaseHash[:]...)
	r = append(r, lease.TunnelIdent[:]...)
	r = append(r, lease.TunnelDate[:]...)
	return r
}