Initial import

protocol/detect_ssh.go

@@ -0,0 +1,51 @@
+package protocol
+
+import (
+	"bytes"
+)
+
+// The required prefix for the SSH protocol identification line.
+const (
+	ssh199Prefix = "SSH-1.99-"
+	ssh20Prefix  = "SSH-2.0-"
+)
+
+func init() {
+	Register(Both, "", detectSSH)
+}
+
+func detectSSH(dir Direction, data []byte) *Protocol {
+	// The data must be at least as long as the prefix itself.
+	if len(data) < len(ssh20Prefix) {
+		return nil
+	}
+
+	// The protocol allows for pre-banner text, so we have to check all lines.
+	for _, line := range bytes.Split(data, []byte{'\n'}) {
+		line = bytes.TrimSuffix(line, []byte{'\r'})
+		if bytes.HasPrefix(line, []byte(ssh20Prefix)) {
+			return &Protocol{
+				Name: ProtocolSSH,
+				Version: Version{
+					Major: 2,
+					Minor: 0,
+					Patch: -1,
+					Extra: string(line[len(ssh20Prefix):]),
+				},
+			}
+		}
+		if bytes.HasPrefix(line, []byte(ssh199Prefix)) {
+			return &Protocol{
+				Name: ProtocolSSH,
+				Version: Version{
+					Major: 1,
+					Minor: 99,
+					Patch: -1,
+					Extra: string(line[len(ssh20Prefix):]),
+				},
+			}
+		}
+	}
+
+	return nil
+}