func serverStateFromJSONServerState(stateDir string, js *jsonServerState) (*obfs4ServerState, error) {
var err error
st := new(obfs4ServerState)
if st.nodeID, err = ntor.NodeIDFromHex(js.NodeID); err != nil {
return nil, err
}
if st.identityKey, err = ntor.KeypairFromHex(js.PrivateKey); err != nil {
return nil, err
}
if st.drbgSeed, err = drbg.SeedFromHex(js.DrbgSeed); err != nil {
return nil, err
}
if js.IATMode < iatNone || js.IATMode > iatParanoid {
return nil, fmt.Errorf("invalid iat-mode '%d'", js.IATMode)
}
st.iatMode = js.IATMode
st.cert = serverCertFromState(st)
// Generate a human readable summary of the configured endpoint.
if err = newBridgeFile(stateDir, st); err != nil {
return nil, err
}
return st, nil
}
func (cf *obfs4ClientFactory) ParseArgs(args *pt.Args) (interface{}, error) {
var nodeID *ntor.NodeID
var publicKey *ntor.PublicKey
// The "new" (version >= 0.0.3) bridge lines use a unified "cert" argument
// for the Node ID and Public Key.
certStr, ok := args.Get(certArg)
if ok {
cert, err := serverCertFromString(certStr)
if err != nil {
return nil, err
}
nodeID, publicKey = cert.unpack()
} else {
// The "old" style (version <= 0.0.2) bridge lines use separate Node ID
// and Public Key arguments in Base16 encoding and are a UX disaster.
nodeIDStr, ok := args.Get(nodeIDArg)
if !ok {
return nil, fmt.Errorf("missing argument '%s'", nodeIDArg)
}
var err error
if nodeID, err = ntor.NodeIDFromHex(nodeIDStr); err != nil {
return nil, err
}
publicKeyStr, ok := args.Get(publicKeyArg)
if !ok {
return nil, fmt.Errorf("missing argument '%s'", publicKeyArg)
}
if publicKey, err = ntor.PublicKeyFromHex(publicKeyStr); err != nil {
return nil, err
}
}
// IAT config is common across the two bridge line formats.
iatStr, ok := args.Get(iatArg)
if !ok {
return nil, fmt.Errorf("missing argument '%s'", iatArg)
}
iatMode, err := strconv.Atoi(iatStr)
if err != nil || iatMode < iatNone || iatMode > iatParanoid {
return nil, fmt.Errorf("invalid iat-mode '%d'", iatMode)
}
// Generate the session key pair before connectiong to hide the Elligator2
// rejection sampling from network observers.
sessionKey, err := ntor.NewKeypair(true)
if err != nil {
return nil, err
}
return &obfs4ClientArgs{nodeID, publicKey, sessionKey, iatMode}, nil
}