maintain general response format for all handlers

.gitignore

@@ -24,3 +24,4 @@ go.work.sum
 # env file
 .env
 wallet.db
+uploads/

aesutils/aes.go

@@ -0,0 +1,72 @@
+package aesutils
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+)
+
+// Encrypt the private key using AES-GCM
+func EncryptPrivateKey(privateKey, secretKey string) (string, error) {
+	// Create an AES cipher
+	block, err := aes.NewCipher([]byte(secretKey)[:32])
+	if err != nil {
+		fmt.Println("failed to create an aes cipher")
+		return "", err
+	}
+
+	// Use AES-GCM for encryption
+	aesGCM, err := cipher.NewGCM(block)
+	if err != nil {
+		fmt.Println("failed to create aes gcm")
+		return "", err
+	}
+
+	// Generate a random nonce
+	nonce := make([]byte, aesGCM.NonceSize())
+	if _, err := rand.Read(nonce); err != nil {
+		fmt.Println("failed to create a random nonce")
+		return "", err
+	}
+
+	// Encrypt the private key
+	ciphertext := aesGCM.Seal(nonce, nonce, []byte(privateKey), nil)
+
+	// Return encrypted data as base64
+	return hex.EncodeToString(ciphertext), nil
+}
+
+// Decrypt the private key
+func DecryptPrivateKey(encryptedKey, secretKey string) (string, error) {
+	ciphertext, err := hex.DecodeString(encryptedKey)
+	if err != nil {
+		return "", nil
+	}
+
+	// Create an AES cipher
+	block, err := aes.NewCipher([]byte(secretKey)[:32])
+	if err != nil {
+		return "", err
+	}
+
+	// Use AES-GCM for decryption
+	aesGCM, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+
+	// Since we know the ciphertext is actually nonce+ciphertext
+	// And len(nonce) == NonceSize(). We can separate the two.
+	nonceSize := aesGCM.NonceSize()
+	nonce, ciphertext := ciphertext[:nonceSize], ciphertext[nonceSize:]
+
+	// Decrypt the private key
+	plaintext, err := aesGCM.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return "", err
+	}
+
+	return string(plaintext), nil
+}

aesutils/aes_test.go

@@ -0,0 +1,33 @@
+package aesutils
+
+import (
+	"testing"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+func AESTest(t *testing.T, privateKey string, secretKey string) {
+	hashedSecretKey, err := bcrypt.GenerateFromPassword([]byte(secretKey), bcrypt.DefaultCost)
+	if err != nil {
+		t.Fatal("could not hash secret key, err", err)
+	}
+
+	key := string(hashedSecretKey[:32])
+
+	encryptedPrivateKey, err := EncryptPrivateKey(privateKey, key)
+	if err != nil {
+		t.Fatal("failed to encrypt private key, err:", err)
+	}
+	decryptedPrivateKey, err := DecryptPrivateKey(encryptedPrivateKey, key)
+	if err != nil {
+		t.Fatal("failed to decrypt private key, err:", err)
+	}
+	if decryptedPrivateKey != privateKey {
+		t.Fatal("mismatched decrypted private key")
+	}
+}
+
+func TestAES(t *testing.T) {
+	AESTest(t, "04b82f061b69471dc877ffc828687970da99fd2d65c6da7f08b9d9a793bf7262", "N1PCdw3M2B1TfJhoaY2mL736p2vCUc47")
+	AESTest(t, "randomstring", "abc123")
+}