// Determines which algorithm to use. Note: f(a, b) = f(b, a)
func SelectBest(myPrefs, theirPrefs string) (string, error) {
// Person with greatest hash gets first choice.
myHash := u.Hash([]byte(myPrefs))
theirHash := u.Hash([]byte(theirPrefs))
cmp := bytes.Compare(myHash, theirHash)
var firstChoiceArr, secChoiceArr []string
if cmp == -1 {
firstChoiceArr = strings.Split(theirPrefs, ",")
secChoiceArr = strings.Split(myPrefs, ",")
} else if cmp == 1 {
firstChoiceArr = strings.Split(myPrefs, ",")
secChoiceArr = strings.Split(theirPrefs, ",")
} else { // Exact same preferences.
myPrefsArr := strings.Split(myPrefs, ",")
return myPrefsArr[0], nil
}
for _, secChoice := range secChoiceArr {
for _, firstChoice := range firstChoiceArr {
if firstChoice == secChoice {
return firstChoice, nil
}
}
}
return "", errors.New("No algorithms in common!")
}
// ID returns the ID of a given Conn.
func ID(c Conn) string {
l := fmt.Sprintf("%s/%s", c.LocalMultiaddr(), c.LocalPeer().ID())
r := fmt.Sprintf("%s/%s", c.RemoteMultiaddr(), c.RemotePeer().ID())
lh := u.Hash([]byte(l))
rh := u.Hash([]byte(r))
ch := u.XOR(lh, rh)
return u.Key(ch).Pretty()
}
// KeyHash hashes a key.
func KeyHash(k Key) ([]byte, error) {
kb, err := k.Bytes()
if err != nil {
return nil, err
}
return u.Hash(kb), nil
}
// IDFromPubKey retrieves a Public Key from the peer given by pk
func IDFromPubKey(pk ic.PubKey) (ID, error) {
b, err := pk.Bytes()
if err != nil {
return nil, err
}
hash := u.Hash(b)
return ID(hash), nil
}
// NewBlockWithHash creates a new block when the hash of the data
// is already known, this is used to save time in situations where
// we are able to be confident that the data is correct
func NewBlockWithHash(data []byte, h mh.Multihash) (*Block, error) {
if u.Debug {
chk := u.Hash(data)
if string(chk) != string(h) {
return nil, errors.New("Data did not match given hash!")
}
}
return &Block{Data: data, Multihash: h}, nil
}
// Encoded returns the encoded raw data version of a Node instance.
// It may use a cached encoded version, unless the force flag is given.
func (n *Node) Encoded(force bool) ([]byte, error) {
if n.encoded == nil || force {
var err error
n.encoded, err = n.Marshal()
if err != nil {
return []byte{}, err
}
n.cached = u.Hash(n.encoded)
}
return n.encoded, nil
}
// ValidatePublicKeyRecord implements ValidatorFunc and
// verifies that the passed in record value is the PublicKey
// that matches the passed in key.
func ValidatePublicKeyRecord(k u.Key, val []byte) error {
keyparts := bytes.Split([]byte(k), []byte("/"))
if len(keyparts) < 3 {
return errors.New("invalid key")
}
pkh := u.Hash(val)
if !bytes.Equal(keyparts[2], pkh) {
return errors.New("public key does not match storage key")
}
return nil
}
func TestRoutingResolve(t *testing.T) {
local := peer.WithIDString("testID")
lds := ds.NewMapDatastore()
d := mock.NewMockRouter(local, lds)
resolver := NewRoutingResolver(d)
publisher := NewRoutingPublisher(d)
privk, pubk, err := ci.GenerateKeyPair(ci.RSA, 512)
if err != nil {
t.Fatal(err)
}
err = publisher.Publish(privk, "Hello")
if err == nil {
t.Fatal("should have errored out when publishing a non-multihash val")
}
h := u.Key(u.Hash([]byte("Hello"))).Pretty()
err = publisher.Publish(privk, h)
if err != nil {
t.Fatal(err)
}
pubkb, err := pubk.Bytes()
if err != nil {
t.Fatal(err)
}
pkhash := u.Hash(pubkb)
res, err := resolver.Resolve(u.Key(pkhash).Pretty())
if err != nil {
t.Fatal(err)
}
if res != h {
t.Fatal("Got back incorrect value.")
}
}
// Publish implements Publisher. Accepts a keypair and a value,
// and publishes it out to the routing system
func (p *ipnsPublisher) Publish(k ci.PrivKey, value string) error {
log.Debugf("namesys: Publish %s", value)
// validate `value` is a ref (multihash)
_, err := mh.FromB58String(value)
if err != nil {
log.Errorf("hash cast failed: %s", value)
return fmt.Errorf("publish value must be str multihash. %v", err)
}
ctx := context.TODO()
data, err := createRoutingEntryData(k, value)
if err != nil {
log.Error("entry creation failed.")
return err
}
pubkey := k.GetPublic()
pkbytes, err := pubkey.Bytes()
if err != nil {
log.Error("pubkey getbytes failed.")
return err
}
nameb := u.Hash(pkbytes)
namekey := u.Key("/pk/" + string(nameb))
log.Debugf("Storing pubkey at: %s", namekey)
// Store associated public key
timectx, _ := context.WithDeadline(ctx, time.Now().Add(time.Second*4))
err = p.routing.PutValue(timectx, namekey, pkbytes)
if err != nil {
return err
}
ipnskey := u.Key("/ipns/" + string(nameb))
log.Debugf("Storing ipns entry at: %s", ipnskey)
// Store ipns entry at "/ipns/"+b58(h(pubkey))
timectx, _ = context.WithDeadline(ctx, time.Now().Add(time.Second*4))
err = p.routing.PutValue(timectx, ipnskey, data)
if err != nil {
return err
}
return nil
}
func TestBlocks(t *testing.T) {
d := ds.NewMapDatastore()
bs, err := NewBlockService(d, nil)
if err != nil {
t.Error("failed to construct block service", err)
return
}
b := blocks.NewBlock([]byte("beep boop"))
h := u.Hash([]byte("beep boop"))
if !bytes.Equal(b.Multihash, h) {
t.Error("Block Multihash and data multihash not equal")
}
if b.Key() != u.Key(h) {
t.Error("Block key and data multihash key not equal")
}
k, err := bs.AddBlock(b)
if err != nil {
t.Error("failed to add block to BlockService", err)
return
}
if k != b.Key() {
t.Error("returned key is not equal to block key", err)
}
ctx, _ := context.WithTimeout(context.TODO(), time.Second*5)
b2, err := bs.GetBlock(ctx, b.Key())
if err != nil {
t.Error("failed to retrieve block from BlockService", err)
return
}
if b.Key() != b2.Key() {
t.Error("Block keys not equal.")
}
if !bytes.Equal(b.Data, b2.Data) {
t.Error("Block data is not equal.")
}
}
func newPeerTime(t time.Time) peer.Peer {
s := fmt.Sprintf("hmmm time: %v", t)
h := u.Hash([]byte(s))
return peer.WithID(peer.ID(h))
}
func RandPeer() peer.Peer {
id := make([]byte, 16)
crand.Read(id)
mhid := u.Hash(id)
return peer.WithID(peer.ID(mhid))
}
// NewBlock creates a Block object from opaque data. It will hash the data.
func NewBlock(data []byte) *Block {
return &Block{Data: data, Multihash: u.Hash(data)}
}
