add b85 (ascii85) hook

1 files changed, 57 insertions, 0 deletions

diff --git a/pkg/server/hook/b85.go b/pkg/server/hook/b85.go
new file mode 100644
index 0000000..9851ffc
--- /dev/null
+++ b/pkg/server/hook/b85.go
@@ -0,0 +1,57 @@
+package hook
+
+import (
+	"encoding/ascii85"
+	"errors"
+	"tunnel/pkg/netstring"
+	"tunnel/pkg/server/env"
+	"tunnel/pkg/server/opts"
+	"tunnel/pkg/server/queue"
+)
+
+type b85Hook struct{}
+
+func (b85Hook) Send(rq, wq queue.Q) error {
+	e := netstring.NewEncoder(wq.Writer())
+
+	for b := range rq {
+		out := make([]byte, ascii85.MaxEncodedLen(len(b)))
+		n := ascii85.Encode(out, b)
+		e.Encode(string(out[:n]))
+	}
+
+	return nil
+}
+
+func (b85Hook) Recv(rq, wq queue.Q) error {
+	d := netstring.NewDecoder(rq.Reader())
+
+	for {
+		s, err := d.Decode()
+		if err != nil {
+			return err
+		}
+
+		out := make([]byte, 4*len(s))
+
+		if n, m, err := ascii85.Decode(out, []byte(s), true); err != nil {
+			return err
+		} else if m != len(s) {
+			return errors.New("decode fail: partial consumption")
+		} else {
+			wq <- out[:n]
+		}
+	}
+}
+
+func (h b85Hook) Open(env.Env) (interface{}, error) {
+	return h, nil
+}
+
+func newB85Hook(opts.Opts, env.Env) (hook, error) {
+	return b85Hook{}, nil
+}
+
+func init() {
+	register("b85", newB85Hook)
+}