1 files changed, 46 insertions, 0 deletions
diff --git a/internal/encoding/ssh/filexfer/extensions.go b/internal/encoding/ssh/filexfer/extensions.go
new file mode 100644
index 0000000..11c0b99
--- /dev/null
+++ b/internal/encoding/ssh/filexfer/extensions.go
@@ -0,0 +1,46 @@
+package filexfer
+
+// ExtensionPair defines the extension-pair type defined in draft-ietf-secsh-filexfer-13.
+// This type is backwards-compatible with how draft-ietf-secsh-filexfer-02 defines extensions.
+//
+// Defined in: https://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-4.2
+type ExtensionPair struct {
+	Name string
+	Data string
+}
+
+// Len returns the number of bytes e would marshal into.
+func (e *ExtensionPair) Len() int {
+	return 4 + len(e.Name) + 4 + len(e.Data)
+}
+
+// MarshalInto marshals e onto the end of the given Buffer.
+func (e *ExtensionPair) MarshalInto(buf *Buffer) {
+	buf.AppendString(e.Name)
+	buf.AppendString(e.Data)
+}
+
+// MarshalBinary returns e as the binary encoding of e.
+func (e *ExtensionPair) MarshalBinary() ([]byte, error) {
+	buf := NewBuffer(make([]byte, 0, e.Len()))
+	e.MarshalInto(buf)
+	return buf.Bytes(), nil
+}
+
+// UnmarshalFrom unmarshals an ExtensionPair from the given Buffer into e.
+func (e *ExtensionPair) UnmarshalFrom(buf *Buffer) (err error) {
+	if e.Name, err = buf.ConsumeString(); err != nil {
+		return err
+	}
+
+	if e.Data, err = buf.ConsumeString(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// UnmarshalBinary decodes the binary encoding of ExtensionPair into e.
+func (e *ExtensionPair) UnmarshalBinary(data []byte) error {
+	return e.UnmarshalFrom(NewBuffer(data))
+}