up/client/main.go

package main

import (
	"context"
	"encoding/base64"
	"errors"
	"fmt"
	"log"
	"os"
	"strings"

	"github.com/urfave/cli/v3"
)

var Version = "dev"

func main() {
	app := &cli.Command{
		Name:    "up",
		Usage:   "UP client",
		Version: Version,
		Flags: []cli.Flag{
			&cli.StringFlag{
				Name:    "key",
				Aliases: []string{"k"},
				Usage:   "private key file for authentication",
			},
			&cli.StringFlag{
				Name:    "file",
				Aliases: []string{"f"},
				Usage:   "file to upload",
			},
			&cli.StringFlag{
				Name:    "target",
				Aliases: []string{"t"},
				Usage:   "target to upload to",
			},
		},
		Action:                 run,
		EnableShellCompletion:  true,
		UseShortOptionHandling: true,
		Suggest:                true,
	}

	if err := app.Run(context.Background(), os.Args); err != nil {
		fmt.Printf("fatal: %v\n", err)

		os.Exit(1)
	}
}

func run(_ context.Context, cmd *cli.Command) error {
	kPath := cmd.String("key")
	if kPath == "" {
		return errors.New("missing private key")
	}

	fPath := cmd.String("file")
	if fPath == "" {
		return errors.New("missing file")
	}

	file, err := os.OpenFile(fPath, os.O_RDONLY, 0)
	if err != nil {
		return fmt.Errorf("failed to open file: %v", err)
	}

	defer file.Close()

	target := cmd.String("target")
	if target == "" {
		return errors.New("missing target")
	}

	if colon := strings.Index(target, ":"); colon != -1 {
		target = fmt.Sprintf("http://%s", target)
	} else {
		target = fmt.Sprintf("https://%s", target)
	}

	private, err := LoadPrivateKey(kPath)
	if err != nil {
		return fmt.Errorf("failed to load key: %v", err)
	}

	public := base64.StdEncoding.EncodeToString(private.PublicKey().Marshal())

	log.Println("Requesting challenge...")

	challenge, err := RequestChallenge(target, public)
	if err != nil {
		return err
	}

	log.Println("Completing challenge...")

	response, err := CompleteChallenge(target, public, private, challenge)
	if err != nil {
		return err
	}

	return SendFile(target, response.Token, file)
}