func writeHC(b *bytes.Buffer, hc *HostConfig, p *sign.Node) error {
// Node{name, pubkey, x_hat, children}
if p == nil {
return errors.New("node does not exist")
}
prk, _ := p.PrivKey.MarshalBinary()
pbk, _ := p.PubKey.MarshalBinary()
fmt.Fprint(b, "{\"name\":", "\""+p.Name()+"\",")
fmt.Fprint(b, "\"prikey\":", "\""+string(hex.EncodeToString(prk))+"\",")
fmt.Fprint(b, "\"pubkey\":", "\""+string(hex.EncodeToString(pbk))+"\",")
// recursively format children
fmt.Fprint(b, "\"children\":[")
i := 0
for _, n := range p.Children(0) {
if i != 0 {
b.WriteString(", ")
}
c := hc.Hosts[n.Name()]
err := writeHC(b, hc, c)
if err != nil {
b.WriteString("\"" + n.Name() + "\"")
}
i++
}
fmt.Fprint(b, "]}")
return nil
}
// dijkstra is actually implemented as BFS right now because it is equivalent
// when edge weights are all 1.
func dijkstra(m map[string]*sign.Node, root *sign.Node) {
l := list.New()
visited := make(map[string]bool)
l.PushFront(root)
visited[root.Name()] = true
for e := l.Front(); e != nil; e = l.Front() {
l.Remove(e)
sn := e.Value.(*sign.Node)
// make all unvisited peers children
// and mark them as visited
for name, conn := range sn.Peers() {
// visited means it is already on the tree.
if visited[name] {
continue
}
visited[name] = true
// add the associated peer/connection as a child
sn.AddChildren(0, conn.Name())
cn, ok := m[name]
if !ok {
panic("error getting connection from map")
}
peers := cn.Peers()
pconn, ok := peers[sn.Name()]
if !ok {
panic("parent connection doesn't exist: not bi-directional")
}
cn.AddParent(0, pconn.Name())
l.PushFront(cn)
}
}
}
func traverseTree(p *sign.Node,
hc *HostConfig,
f func(*sign.Node, *HostConfig) error) error {
if err := f(p, hc); err != nil {
return err
}
for _, cn := range p.Children(0) {
c := hc.Hosts[cn.Name()]
err := traverseTree(c, hc, f)
if err != nil {
return err
}
}
return nil
}
// ConstructTree does a depth-first construction of the tree specified in the
// config file. ConstructTree must be called AFTER populating the HostConfig with
// ALL the possible hosts.
func ConstructTree(
n *Node,
hc *HostConfig,
parent string,
suite abstract.Suite,
rand cipher.Stream,
hosts map[string]coconet.Host,
nameToAddr map[string]string,
opts ConfigOptions) (int, error) {
// passes up its X_hat, and/or an error
// get the name associated with this address
name, ok := nameToAddr[n.Name]
if !ok {
fmt.Println("unknown name in address book:", n.Name)
return 0, errors.New("unknown name in address book")
}
// generate indicates whether we should generate the signing
// node for this hostname
generate := opts.Host == "" || opts.Host == name
// check to make sure the this hostname is in the tree
// it can be backed by a nil pointer
h, ok := hosts[name]
if !ok {
fmt.Println("unknown host in tree:", name)
return 0, errors.New("unknown host in tree")
}
var prikey abstract.Secret
var pubkey abstract.Point
var sn *sign.Node
// if the JSON holds the fields field is set load from there
if len(n.PubKey) != 0 {
// log.Println("decoding point")
encoded, err := hex.DecodeString(string(n.PubKey))
if err != nil {
log.Print("failed to decode hex from encoded")
return 0, err
}
pubkey = suite.Point()
err = pubkey.UnmarshalBinary(encoded)
if err != nil {
log.Print("failed to decode point from hex")
return 0, err
}
// log.Println("decoding point")
encoded, err = hex.DecodeString(string(n.PriKey))
if err != nil {
log.Print("failed to decode hex from encoded")
return 0, err
}
prikey = suite.Secret()
err = prikey.UnmarshalBinary(encoded)
if err != nil {
log.Print("failed to decode point from hex")
return 0, err
}
}
if generate {
if prikey != nil {
// if we have been given a private key load that
aux := sign.NewKeyedNode(h, suite, prikey)
aux.GenSetPool()
hc.SNodes = append(hc.SNodes, aux)
h.SetPubKey(pubkey)
} else {
// otherwise generate a random new one
sn := sign.NewNode(h, suite, rand)
sn.GenSetPool()
hc.SNodes = append(hc.SNodes, sn)
h.SetPubKey(sn.PubKey)
}
sn = hc.SNodes[len(hc.SNodes)-1]
hc.Hosts[name] = sn
if prikey == nil {
prikey = sn.PrivKey
pubkey = sn.PubKey
}
// log.Println("pubkey:", sn.PubKey)
// log.Println("given: ", pubkey)
}
// if the parent of this call is empty then this must be the root node
if parent != "" && generate {
h.AddParent(0, parent)
}
// log.Println("name: ", n.Name)
// log.Println("prikey: ", prikey)
// log.Println("pubkey: ", pubkey)
height := 0
for _, c := range n.Children {
// connect this node to its children
cname, ok := nameToAddr[c.Name]
if !ok {
fmt.Println("unknown name in address book:", n.Name)
return 0, errors.New("unknown name in address book")
}
if generate {
h.AddChildren(0, cname)
}
// recursively construct the children
// log.Print("ConstructTree:", h, suite, rand, hosts, nameToAddr, opts)
h, err := ConstructTree(c, hc, name, suite, rand, hosts, nameToAddr, opts)
if err != nil {
return 0, err
}
height = max(h+1, height)
// if generating all csn will be availible
}
if generate {
sn.Height = height
}
// log.Println("name: ", n.Name)
// log.Println("final x_hat: ", x_hat)
// log.Println("final pubkey: ", pubkey)
return height, nil
}