obfsvpn: initial draft library API

Signed-off-by: Sam Whited <sam@samwhited.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/dialer.go b/dialer.go
new file mode 100644
index 0000000..0c3f8c3
--- /dev/null
+++ b/dialer.go
@@ -0,0 +1,57 @@
+package obfsvpn
+
+import (
+	"context"
+	"net"
+	"strconv"
+
+	pt "git.torproject.org/pluggable-transports/goptlib.git"
+	"gitlab.com/yawning/obfs4.git/common/ntor"
+	"gitlab.com/yawning/obfs4.git/transports/base"
+	"gitlab.com/yawning/obfs4.git/transports/obfs4"
+)
+
+// IATMode determines the amount of time sent between packets.
+type IATMode int
+
+// Valid IAT modes.
+const (
+	IATNone IATMode = iota
+	IATEnabled
+	IATParanoid
+)
+
+// Dialer contains options for connecting to an address and obfuscating traffic
+// with the obfs4 protocol.
+// It performs the ntor handshake on all dialed connections.
+type Dialer struct {
+	Dialer net.Dialer
+
+	NodeID    *ntor.NodeID
+	PublicKey *ntor.PublicKey
+	IATMode   IATMode
+
+	cf base.ClientFactory
+}
+
+// Dial creates an outbound net.Conn and performs the ntor handshake.
+func (d *Dialer) Dial(ctx context.Context, network, address string) (net.Conn, error) {
+	if d.cf == nil {
+		cf, err := (&obfs4.Transport{}).ClientFactory("")
+		if err != nil {
+			return nil, err
+		}
+		d.cf = cf
+	}
+	ptArgs := make(pt.Args)
+	ptArgs.Add("node-id", d.NodeID.Hex())
+	ptArgs.Add("public-key", d.PublicKey.Hex())
+	ptArgs.Add("iat-mode", strconv.Itoa(int(d.IATMode)))
+	args, err := d.cf.ParseArgs(&ptArgs)
+	if err != nil {
+		return nil, err
+	}
+	return d.cf.Dial(network, address, func(network, address string) (net.Conn, error) {
+		return d.Dialer.DialContext(ctx, network, address)
+	}, args)
+}