diff --git a/README.md b/README.md new file mode 100644 index 0000000..2f6c4ce --- /dev/null +++ b/README.md @@ -0,0 +1,5 @@ +# go-dht + +Kademlia DHT Go implementation. + +Following the specification from https://pdos.csail.mit.edu/~petar/papers/maymounkov-kademlia-lncs.pdf and http://xlattice.sourceforge.net/components/protocol/kademlia/specs.html diff --git a/go.mod b/go.mod new file mode 100644 index 0000000..eebb211 --- /dev/null +++ b/go.mod @@ -0,0 +1,5 @@ +module go-dht + +go 1.12 + +require github.com/stretchr/testify v1.4.0 diff --git a/go.sum b/go.sum new file mode 100644 index 0000000..e863f51 --- /dev/null +++ b/go.sum @@ -0,0 +1,10 @@ +github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8= +github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM= +github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4= +github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME= +github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk= +github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4= +gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0= +gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw= +gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI= diff --git a/id.go b/id.go new file mode 100644 index 0000000..09d14f7 --- /dev/null +++ b/id.go @@ -0,0 +1,51 @@ +package main + +import ( + "crypto/rand" + "encoding/hex" +) + +type ID [B]byte + +func NewID() (ID, error) { + b := make([]byte, 32) + _, err := rand.Read(b) + if err != nil { + return ID{}, err + } + var id ID + copy(id[:], b[:B]) + return id, nil +} + +func (id ID) String() string { + return hex.EncodeToString(id[:]) +} + +func IDFromString(s string) (ID, error) { + b, err := hex.DecodeString(s) + if err != nil { + return ID{}, err + } + var id ID + copy(id[:], b[:B]) + return id, nil +} + +// Cmp returns true if idA > idB +func (idA ID) Cmp(idB ID) bool { + for i := 0; i < len(idA); i++ { + if idA[i] != idB[i] { + return idA[i] > idB[i] + } + } + return false +} + +func (idA ID) Distance(idB ID) ID { + var d ID + for i := 0; i < B; i++ { + d[i] = idA[i] ^ idB[i] + } + return d +} diff --git a/id_test.go b/id_test.go new file mode 100644 index 0000000..8993272 --- /dev/null +++ b/id_test.go @@ -0,0 +1,32 @@ +package main + +import ( + "testing" + + "github.com/stretchr/testify/assert" +) + +func TestNewID(t *testing.T) { + _, err := NewID() + assert.Nil(t, err) + + idA, err := IDFromString("0fd85ddddf15aeec2d5d8b01b013dbca030a18d7") + assert.Nil(t, err) + assert.Equal(t, "0fd85ddddf15aeec2d5d8b01b013dbca030a18d7", idA.String()) +} + +func TestIDCmp(t *testing.T) { + idA, err := IDFromString("0fd85ddddf15aeec2d5d8b01b013dbca030a18d7") + assert.Nil(t, err) + idB, err := IDFromString("c48d8b53dbefb609ed4e94d386dd5b22efcb2c5b") + assert.Nil(t, err) + assert.True(t, !idA.Cmp(idB)) +} + +func TestIDDistance(t *testing.T) { + idA, err := IDFromString("0fd85ddddf15aeec2d5d8b01b013dbca030a18d7") + assert.Nil(t, err) + idB, err := IDFromString("c48d8b53dbefb609ed4e94d386dd5b22efcb2c5b") + assert.Nil(t, err) + assert.Equal(t, "cb55d68e04fa18e5c0131fd236ce80e8ecc1348c", idA.Distance(idB).String()) +}