feat: add tool aes

tool/aes.go

@@ -0,0 +1,95 @@
+package tool
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"io"
+)
+
+// AES加密（CBC模式，PKCS7填充）
+func AesEncrypt(data []byte, key []byte) (string, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return "", err
+	}
+
+	// 添加PKCS7填充
+	data = pkcs7Pad(data, block.BlockSize())
+
+	// 创建存储密文的buffer，前aes.BlockSize字节存储IV
+	ciphertext := make([]byte, aes.BlockSize+len(data))
+	iv := ciphertext[:aes.BlockSize]
+	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
+		return "", err
+	}
+
+	// CBC加密
+	mode := cipher.NewCBCEncrypter(block, iv)
+	mode.CryptBlocks(ciphertext[aes.BlockSize:], data)
+
+	return base64.StdEncoding.EncodeToString(ciphertext), nil
+}
+
+// AES解密（CBC模式，PKCS7填充）
+func AesDecrypt(encrypted string, key []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	ciphertext, err := base64.StdEncoding.DecodeString(encrypted)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(ciphertext) < aes.BlockSize {
+		return nil, errors.New("ciphertext too short")
+	}
+
+	iv := ciphertext[:aes.BlockSize]
+	ciphertext = ciphertext[aes.BlockSize:]
+
+	if len(ciphertext)%aes.BlockSize != 0 {
+		return nil, errors.New("ciphertext is not a multiple of the block size")
+	}
+
+	// CBC解密
+	mode := cipher.NewCBCDecrypter(block, iv)
+	mode.CryptBlocks(ciphertext, ciphertext)
+
+	// 去除PKCS7填充
+	return pkcs7Unpad(ciphertext)
+}
+
+// PKCS7填充
+func pkcs7Pad(data []byte, blockSize int) []byte {
+	padding := blockSize - (len(data) % blockSize)
+	padText := bytes.Repeat([]byte{byte(padding)}, padding)
+	return append(data, padText...)
+}
+
+// PKCS7去除填充
+func pkcs7Unpad(data []byte) ([]byte, error) {
+	length := len(data)
+	if length == 0 {
+		return nil, errors.New("empty input")
+	}
+
+	padding := int(data[length-1])
+	if padding > length || padding == 0 {
+		return nil, errors.New("invalid padding")
+	}
+
+	// 验证填充字节是否正确
+	for i := length - padding; i < length; i++ {
+		if int(data[i]) != padding {
+			return nil, errors.New("invalid padding")
+		}
+	}
+
+	return data[:length-padding], nil
+}

tool/aes_test.go

@@ -0,0 +1,25 @@
+package tool
+
+import (
+	"os"
+	"testing"
+)
+
+func TestAes(t *testing.T) {
+	key := os.Getenv("AES_KEY")
+
+	name := "admin"
+	res, err := AesEncrypt([]byte(name), []byte(key))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Logf("res = %s", string(res))
+
+	raw, err := AesDecrypt(res, []byte(key))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Logf("raw = %s", string(raw))
+}