Initial commit with base64 encoder

cmd/pencode/main.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/ffuf/pencode/pkg/pencode"
+)
+
+func main() {
+	chain := pencode.NewChain()
+	flag.Usage = func() {
+		fmt.Printf("pencode - complex payload encoder v%s\n\n", pencode.VERSION)
+		fmt.Printf("Usage: %s ENCODER1 ENCODER2 ENCODER3...\n\n", os.Args[0])
+		fmt.Printf("%s reads input from stdin, which is typically piped from another process.\n\n", os.Args[0])
+		fmt.Printf("Available encoders:\n")
+		chain.Usage()
+	}
+	flag.Parse()
+	if len(os.Args) < 2 {
+		flag.Usage()
+		os.Exit(1)
+	}
+	err := chain.Initialize(os.Args[1:])
+	if err != nil {
+		flag.Usage()
+		fmt.Printf("\n[!] %s", err)
+		os.Exit(1)
+	}
+
+	input := readInput()
+	output, err := chain.Encode([]byte(input))
+	if err != nil {
+		fmt.Printf("  [!] %s", err)
+	}
+	fmt.Print(string(output))
+}
+
+func readInput() string {
+	input := os.Stdin
+	defer input.Close()
+	reader := bufio.NewScanner(input)
+
+	data := ""
+	for reader.Scan() {
+		data = data + reader.Text()
+	}
+	return data
+}

go.mod

@@ -0,0 +1,3 @@
+module "github.com/ffuf/pencode"
+
+go 1.14

pkg/pencode/base64encode.go

@@ -0,0 +1,16 @@
+package pencode
+
+import (
+	"encoding/base64"
+)
+
+type Base64Encoder struct{}
+
+func (b Base64Encoder) Encode(input []byte) ([]byte, error) {
+	output := base64.StdEncoding.EncodeToString(input)
+	return []byte(output), nil
+}
+
+func (b Base64Encoder) HelpText() string {
+	return "Base64 encoder"
+}

pkg/pencode/constants.go

@@ -0,0 +1,3 @@
+package pencode
+
+const VERSION = "0.1"

pkg/pencode/encoders.go

@@ -0,0 +1,74 @@
+package pencode
+
+import (
+	"fmt"
+)
+
+var availableEncoders = map[string]Encoder{
+	"b64encode": Base64Encoder{},
+}
+
+type Chain struct {
+	Encoders    []Encoder
+	initialized bool
+	actions     []string
+}
+
+func NewChain() *Chain {
+	c := Chain{initialized: false}
+	return &c
+}
+
+//Initialize loops through requested names for encoders and sets up the encoder chain. If an unknown encoder is
+//requested, error will be returned.
+func (c *Chain) Initialize(actions []string) error {
+	c.actions = actions
+	c.Encoders = make([]Encoder, 0)
+	for _, a := range actions {
+		if c.HasEncoder(a) {
+			c.Encoders = append(c.Encoders, availableEncoders[a])
+		} else {
+			return fmt.Errorf("Encoder %s requested but not found.\n", a)
+		}
+	}
+	c.initialized = true
+	return nil
+}
+
+func (c *Chain) Encode(input []byte) ([]byte, error) {
+	var err error
+	if !c.initialized {
+		return []byte{}, fmt.Errorf("Encoder chain not initialized.\n")
+	}
+	for _, e := range c.Encoders {
+		input, err = e.Encode(input)
+		if err != nil {
+			return []byte{}, err
+		}
+	}
+	return input, nil
+}
+
+//HasEncoder returns true if encoder with a specified name is configured
+func (c *Chain) HasEncoder(name string) bool {
+	if _, ok := availableEncoders[name]; ok {
+		return true
+	}
+	return false
+}
+
+//Usage prints the help string for each  configured encoder
+func (c *Chain) Usage() {
+	// Calculate maximum keyword length for nice help formatting
+	max_length := 0
+	for k := range availableEncoders {
+		if len(k) > max_length {
+			max_length = len(k)
+		}
+	}
+	format := fmt.Sprintf("  %%-%ds- %%s\n", max_length+2)
+
+	for k, v := range availableEncoders {
+		fmt.Printf(format, k, v.HelpText())
+	}
+}

pkg/pencode/interfaces.go

@@ -0,0 +1,6 @@
+package pencode
+
+type Encoder interface {
+	Encode([]byte) ([]byte, error)
+	HelpText() string
+}