[🚀] add crypto pkg

pkg/crypto/compress.go

@@ -0,0 +1,71 @@
+package crypto
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io"
+)
+
+// CompressEncryptor 压缩加密器
+type CompressEncryptor struct {
+	baseEncryptor Encryptor
+}
+
+func NewCompressEncryptor(encryptor Encryptor) *CompressEncryptor {
+	return &CompressEncryptor{baseEncryptor: encryptor}
+}
+
+// Encrypt 先压缩后加密
+func (c *CompressEncryptor) Encrypt(plaintext []byte) ([]byte, error) {
+	// 1. 压缩
+	compressed, err := c.compress(plaintext)
+	if err != nil {
+		return nil, err
+	}
+
+	// 2. 加密
+	return c.baseEncryptor.Encrypt(compressed)
+}
+
+// Decrypt 先解密后解压
+func (c *CompressEncryptor) Decrypt(ciphertext []byte) ([]byte, error) {
+	// 1. 解密
+	compressed, err := c.baseEncryptor.Decrypt(ciphertext)
+	if err != nil {
+		return nil, err
+	}
+
+	// 2. 解压
+	return c.decompress(compressed)
+}
+
+func (c *CompressEncryptor) Name() string {
+	return "GZIP-" + c.baseEncryptor.Name()
+}
+
+// compress 使用gzip压缩
+func (c *CompressEncryptor) compress(data []byte) ([]byte, error) {
+	var buf bytes.Buffer
+	writer := gzip.NewWriter(&buf)
+
+	if _, err := writer.Write(data); err != nil {
+		return nil, err
+	}
+
+	if err := writer.Close(); err != nil {
+		return nil, err
+	}
+
+	return buf.Bytes(), nil
+}
+
+// decompress 使用gzip解压
+func (c *CompressEncryptor) decompress(data []byte) ([]byte, error) {
+	reader, err := gzip.NewReader(bytes.NewReader(data))
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = reader.Close() }()
+
+	return io.ReadAll(reader)
+}