finished the duckyscript parser

modules/hid/duckyparser.go

@@ -0,0 +1,187 @@
+package hid
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/evilsocket/islazy/fs"
+)
+
+type DuckyParser struct {
+	mod *HIDRecon
+}
+
+func (p DuckyParser) parseLiteral(what string, kmap KeyMap) (*Command, error) {
+	// get reference command from the layout
+	ref, found := kmap[what]
+	if found == false {
+		return nil, fmt.Errorf("can't find '%s' in current keymap", what)
+	}
+	return &Command{
+		HID:  ref.HID,
+		Mode: ref.Mode,
+	}, nil
+}
+
+func (p DuckyParser) parseModifier(line string, kmap KeyMap, modMask byte) (*Command, error) {
+	// get optional key after the modifier
+	ch := ""
+	if idx := strings.IndexRune(line, ' '); idx != -1 {
+		ch = line[idx+1:]
+	}
+	cmd, err := p.parseLiteral(ch, kmap)
+	if err != nil {
+		return nil, err
+	}
+	// apply modifier mask
+	cmd.Mode |= modMask
+	return cmd, nil
+}
+
+func (p DuckyParser) parseNumber(from string) (int, error) {
+	idx := strings.IndexRune(from, ' ')
+	if idx == -1 {
+		return 0, fmt.Errorf("can't parse number from '%s'", from)
+	}
+
+	num, err := strconv.Atoi(from[idx+1:])
+	if err != nil {
+		return 0, fmt.Errorf("can't parse number from '%s': %v", from, err)
+	}
+
+	return num, nil
+}
+
+func (p DuckyParser) parseString(from string) (string, error) {
+	idx := strings.IndexRune(from, ' ')
+	if idx == -1 {
+		return "", fmt.Errorf("can't parse string from '%s'", from)
+	}
+	return from[idx+1:], nil
+}
+
+func (p DuckyParser) lineIs(line string, tokens ...string) bool {
+	for _, tok := range tokens {
+		if strings.HasPrefix(line, tok) {
+			return true
+		}
+	}
+	return false
+}
+
+func (p DuckyParser) Parse(kmap KeyMap, path string) (cmds []*Command, err error) {
+	lines := []string{}
+	source := []string{}
+	reader := (chan string)(nil)
+
+	if reader, err = fs.LineReader(path); err != nil {
+		return
+	} else {
+		for line := range reader {
+			lines = append(lines, line)
+		}
+	}
+
+	// preprocessing
+	for lineno, line := range lines {
+		if p.lineIs(line, "REPEAT") {
+			if lineno == 0 {
+				err = fmt.Errorf("error on line %d: REPEAT instruction at the beginning of the script", lineno+1)
+				return
+			}
+			times := 1
+			times, err = p.parseNumber(line)
+			if err != nil {
+				return
+			}
+
+			for i := 0; i < times; i++ {
+				source = append(source, lines[lineno-1])
+			}
+		} else {
+			source = append(source, line)
+		}
+	}
+
+	cmds = make([]*Command, 0)
+	for lineno, line := range source {
+		cmd := &Command{}
+		if p.lineIs(line, "CTRL", "CONTROL") {
+			if cmd, err = p.parseModifier(line, kmap, 1); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "SHIFT") {
+			if cmd, err = p.parseModifier(line, kmap, 2); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "ALT") {
+			if cmd, err = p.parseModifier(line, kmap, 4); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "GUI", "WINDOWS", "COMMAND") {
+			if cmd, err = p.parseModifier(line, kmap, 8); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "CTRL-ALT", "CONTROL-ALT") {
+			if cmd, err = p.parseModifier(line, kmap, 4|1); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "CTRL-SHIFT", "CONTROL-SHIFT") {
+			if cmd, err = p.parseModifier(line, kmap, 1|2); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "ESC", "ESCAPE", "APP") {
+			if cmd, err = p.parseLiteral("ESCAPE", kmap); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "ENTER") {
+			if cmd, err = p.parseLiteral("ENTER", kmap); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "UP", "UPARROW") {
+			if cmd, err = p.parseLiteral("UP", kmap); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "DOWN", "DOWNARROW") {
+			if cmd, err = p.parseLiteral("DOWN", kmap); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "LEFT", "LEFTARROW") {
+			if cmd, err = p.parseLiteral("LEFT", kmap); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "RIGHT", "RIGHTARROW") {
+			if cmd, err = p.parseLiteral("RIGHT", kmap); err != nil {
+				return
+			}
+		} else if p.lineIs(line, "DELAY", "SLEEP") {
+			secs := 0
+			if secs, err = p.parseNumber(line); err != nil {
+				return
+			}
+			cmd = &Command{Sleep: secs}
+		} else if p.lineIs(line, "STRING", "STR") {
+			str := ""
+			if str, err = p.parseString(line); err != nil {
+				return
+			}
+
+			for _, c := range str {
+				if cmd, err = p.parseLiteral(string(c), kmap); err != nil {
+					return
+				}
+				cmds = append(cmds, cmd)
+			}
+
+			continue
+		} else {
+			err = fmt.Errorf("can't parse line %d ('%s') of %s", lineno+1, line, path)
+			return
+		}
+
+		cmds = append(cmds, cmd)
+	}
+
+	return
+}