feat: encryption cmds (#4)

Author: thewhitewizard

cmd/encryption/encryption.go

@@ -0,0 +1,252 @@
+package encryption
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+const (
+	AESKeySize256 = 256
+
+	secretDirPerm   = 0700
+	keyFilePerm     = 0600
+	bitsToByteRatio = 8
+)
+
+var EncryptionCmd = &cobra.Command{
+	Use:   "encryption",
+	Short: "🔐 Manage data encryption and decryption",
+}
+
+func init() {
+	EncryptionCmd.AddCommand(aesEncryptCommand())
+	EncryptionCmd.AddCommand(aesDecryptCommand())
+	EncryptionCmd.AddCommand(aesGenerateKeyCommand())
+}
+
+func aesEncryptCommand() *cobra.Command {
+	var inputPath, outputPath, keyPath string
+
+	cmd := &cobra.Command{
+		Use:   "encrypt",
+		Short: "🔒 Encrypt a file using AES (key is base64-encoded in a file)",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			fmt.Println("🔐 Starting AES encryption...")
+
+			keyB64, err := os.ReadFile(keyPath)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to read key file: %w", err)
+			}
+			key, err := base64.StdEncoding.DecodeString(string(keyB64))
+			if err != nil {
+				return fmt.Errorf("❌ Failed to decode base64 key: %w", err)
+			}
+			if len(key) != (AESKeySize256 / bitsToByteRatio) {
+				return fmt.Errorf("❌ Invalid AES key length: %d bytes", len(key))
+			}
+
+			plaintext, err := os.ReadFile(inputPath)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to read input file: %w", err)
+			}
+
+			plaintext = pkcs7Pad(plaintext, aes.BlockSize)
+
+			block, err := aes.NewCipher(key)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to create cipher: %w", err)
+			}
+
+			iv := make([]byte, aes.BlockSize)
+			if _, errGenIV := rand.Read(iv); errGenIV != nil {
+				return fmt.Errorf("❌ Failed to generate IV: %w", errGenIV)
+			}
+
+			ciphertext := make([]byte, len(plaintext))
+			mode := cipher.NewCBCEncrypter(block, iv)
+			mode.CryptBlocks(ciphertext, plaintext)
+
+			outFile, err := os.Create(outputPath)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to create output file: %w", err)
+			}
+			defer outFile.Close()
+
+			if _, err := outFile.Write(iv); err != nil {
+				return fmt.Errorf("❌ Failed to write IV: %w", err)
+			}
+			if _, err := outFile.Write(ciphertext); err != nil {
+				return fmt.Errorf("❌ Failed to write ciphertext: %w", err)
+			}
+
+			fmt.Println("✅ File encrypted! 📁 Saved to:", outputPath)
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVarP(&inputPath, "in", "i", "", "Plaintext input file path")
+	cmd.Flags().StringVarP(&outputPath, "out", "o", "", "Encrypted output file path")
+	cmd.Flags().StringVarP(&keyPath, "key", "k", "", "Base64-encoded AES key file")
+
+	if err := cmd.MarkFlagRequired("in"); err != nil {
+		log.Fatalf("❌ Failed to mark 'in' flag as required: %v", err)
+	}
+
+	if err := cmd.MarkFlagRequired("out"); err != nil {
+		log.Fatalf("❌ Failed to mark 'out' flag as required: %v", err)
+	}
+
+	if err := cmd.MarkFlagRequired("key"); err != nil {
+		log.Fatalf("❌ Failed to mark 'key' flag as required: %v", err)
+	}
+
+	return cmd
+}
+
+func aesDecryptCommand() *cobra.Command {
+	var inputPath, outputPath, keyPath string
+
+	cmd := &cobra.Command{
+		Use:   "decrypt",
+		Short: "🔓 Decrypt a file using AES (key is base64-encoded in a file)",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			fmt.Println("🔓 Starting AES decryption...")
+
+			keyB64, err := os.ReadFile(keyPath)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to read key file: %w", err)
+			}
+			key, err := base64.StdEncoding.DecodeString(string(keyB64))
+			if err != nil {
+				return fmt.Errorf("❌ Failed to decode base64 key: %w", err)
+			}
+			if len(key) != (AESKeySize256 / bitsToByteRatio) {
+				return fmt.Errorf("❌ Invalid AES key length: %d bytes", len(key))
+			}
+
+			inFile, err := os.Open(inputPath)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to open input file: %w", err)
+			}
+			defer inFile.Close()
+
+			iv := make([]byte, aes.BlockSize)
+			if _, errReadIV := io.ReadFull(inFile, iv); errReadIV != nil {
+				return fmt.Errorf("❌ Failed to read IV: %w", errReadIV)
+			}
+
+			ciphertext, err := io.ReadAll(inFile)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to read ciphertext: %w", err)
+			}
+			if len(ciphertext)%aes.BlockSize != 0 {
+				return errors.New("❌ Ciphertext is not a multiple of the block size")
+			}
+
+			block, err := aes.NewCipher(key)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to create cipher: %w", err)
+			}
+
+			mode := cipher.NewCBCDecrypter(block, iv)
+			plaintext := make([]byte, len(ciphertext))
+			mode.CryptBlocks(plaintext, ciphertext)
+
+			plaintext, err = pkcs7Unpad(plaintext)
+			if err != nil {
+				return fmt.Errorf("❌ Failed to unpad plaintext: %w", err)
+			}
+
+			if err := os.WriteFile(outputPath, plaintext, keyFilePerm); err != nil {
+				return fmt.Errorf("❌ Failed to write output file: %w", err)
+			}
+
+			fmt.Println("✅ File decrypted! 📁 Saved to:", outputPath)
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVarP(&inputPath, "in", "i", "", "Encrypted input file path")
+	cmd.Flags().StringVarP(&outputPath, "out", "o", "", "Decrypted output file path")
+	cmd.Flags().StringVarP(&keyPath, "key", "k", "", "Base64-encoded AES key file")
+
+	if err := cmd.MarkFlagRequired("in"); err != nil {
+		log.Fatalf("❌ Failed to mark 'in' flag as required: %v", err)
+	}
+
+	if err := cmd.MarkFlagRequired("out"); err != nil {
+		log.Fatalf("❌ Failed to mark 'out' flag as required: %v", err)
+	}
+
+	if err := cmd.MarkFlagRequired("key"); err != nil {
+		log.Fatalf("❌ Failed to mark 'key' flag as required: %v", err)
+	}
+
+	return cmd
+}
+
+func aesGenerateKeyCommand() *cobra.Command {
+	var output string
+
+	cmd := &cobra.Command{
+		Use:   "genkey",
+		Short: "🔑 Generate a random AES key and store it in base64 in .secrets/",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			keyLen := AESKeySize256 / bitsToByteRatio
+			key := make([]byte, keyLen)
+			if _, err := rand.Read(key); err != nil {
+				return fmt.Errorf("❌ Failed to generate key: %w", err)
+			}
+
+			b64Key := base64.StdEncoding.EncodeToString(key)
+
+			if output == "" {
+				if err := os.MkdirAll(".secrets", secretDirPerm); err != nil {
+					return fmt.Errorf("❌ Failed to create secrets directory: %w", err)
+				}
+				output = fmt.Sprintf(".secrets/aes-key-%d.b64", AESKeySize256)
+			}
+
+			if err := os.WriteFile(output, []byte(b64Key), keyFilePerm); err != nil {
+				return fmt.Errorf("❌ Failed to write key file: %w", err)
+			}
+
+			fmt.Printf("✅ AES-%d key generated and saved to %s\n", AESKeySize256, output)
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVarP(&output, "out", "o", "", "Output file path (default: .secrets/aes-key-<size>.b64)")
+
+	return cmd
+}
+
+func pkcs7Pad(data []byte, blockSize int) []byte {
+	padding := blockSize - len(data)%blockSize
+	padText := bytes.Repeat([]byte{byte(padding)}, padding)
+
+	return append(data, padText...)
+}
+
+func pkcs7Unpad(data []byte) ([]byte, error) {
+	if len(data) == 0 {
+		return nil, errors.New("invalid padding size")
+	}
+	paddingLen := int(data[len(data)-1])
+
+	if paddingLen == 0 || paddingLen > len(data) {
+		return nil, errors.New("invalid padding")
+	}
+
+	return data[:len(data)-paddingLen], nil
+}

cmd/root.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"github.com/thewhitewizard/web3data-cli/cmd/encryption"
 	"github.com/thewhitewizard/web3data-cli/cmd/ipfs"
 	"github.com/thewhitewizard/web3data-cli/cmd/version"
 
@@ -17,6 +18,7 @@ func Execute() {
 }
 
 func init() {
+	rootCmd.AddCommand(encryption.EncryptionCmd)
 	rootCmd.AddCommand(ipfs.IPFSCmd)
 	rootCmd.AddCommand(version.VersionCmd)
 }