From: Matt Joiner <anacrolix@gmail.com>
Date: Tue, 4 Aug 2015 16:37:43 +0000 (+1000)
Subject: dht: Expose SecureNodeId and NodeIdSecure
X-Git-Tag: v1.0.0~1081
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=a0cdda16a4017cae4b267bd1367461319cd6674d;p=btrtrc.git

dht: Expose SecureNodeId and NodeIdSecure
---

diff --git a/dht/dht.go b/dht/dht.go
index 17ead0b4..6585a6ce 100644
--- a/dht/dht.go
+++ b/dht/dht.go
@@ -221,7 +221,7 @@ func (n *node) IsSecure() bool {
 	if n.id.IsUnset() {
 		return false
 	}
-	return nodeIdSecure(n.id.ByteString(), n.addr.IP())
+	return NodeIdSecure(n.id.ByteString(), n.addr.IP())
 }
 
 func (n *node) idString() string {
@@ -521,16 +521,18 @@ func crcIP(ip net.IP, rand uint8) uint32 {
 	return crc32.Checksum(ip[:len(mask)], crc32.MakeTable(crc32.Castagnoli))
 }
 
-// Makes a node ID valid, in-place.
-func secureNodeId(id []byte, ip net.IP) {
+// Makes a node ID secure, in-place. The ID is 20 raw bytes.
+// http://www.libtorrent.org/dht_sec.html
+func SecureNodeId(id []byte, ip net.IP) {
 	crc := crcIP(ip, id[19])
 	id[0] = byte(crc >> 24 & 0xff)
 	id[1] = byte(crc >> 16 & 0xff)
 	id[2] = byte(crc>>8&0xf8) | id[2]&7
 }
 
-// http://www.libtorrent.org/dht_sec.html
-func nodeIdSecure(id string, ip net.IP) bool {
+// Returns whether the node ID is considered secure. The id is the 20 raw
+// bytes. http://www.libtorrent.org/dht_sec.html
+func NodeIdSecure(id string, ip net.IP) bool {
 	if len(id) != 20 {
 		panic(fmt.Sprintf("%q", id))
 	}
@@ -573,7 +575,7 @@ func (s *Server) setDefaults() (err error) {
 				return missinggo.AddrIP(s.socket.LocalAddr())
 			}
 		}()
-		secureNodeId(id[:], publicIP)
+		SecureNodeId(id[:], publicIP)
 		s.id = string(id[:])
 	}
 	s.nodes = make(map[string]*node, maxNodes)
diff --git a/dht/dht_test.go b/dht/dht_test.go
index a797a606..e1583460 100644
--- a/dht/dht_test.go
+++ b/dht/dht_test.go
@@ -188,13 +188,13 @@ func TestDHTSec(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		secure := nodeIdSecure(string(id), ip)
+		secure := NodeIdSecure(string(id), ip)
 		if secure != case_.valid {
 			t.Fatalf("case failed: %v", case_)
 		}
 		if !secure {
-			secureNodeId(id, ip)
-			if !nodeIdSecure(string(id), ip) {
+			SecureNodeId(id, ip)
+			if !NodeIdSecure(string(id), ip) {
 				t.Fatal("failed to secure node id")
 			}
 		}
@@ -207,7 +207,7 @@ func TestServerDefaultNodeIdSecure(t *testing.T) {
 		t.Fatal(err)
 	}
 	defer s.Close()
-	if !nodeIdSecure(s.ID(), missinggo.AddrIP(s.Addr())) {
+	if !NodeIdSecure(s.ID(), missinggo.AddrIP(s.Addr())) {
 		t.Fatal("not secure")
 	}
 }