first commit

internal/helpers/bpjs/lz-string.go

@@ -0,0 +1,83 @@
+package helper
+
+import (
+	"log"
+
+	lzstring "github.com/daku10/go-lz-string"
+)
+
+// StringDecrypt - langsung coba decompress tanpa decrypt ulang
+func StringDecrypt(key string, encryptedString string) (string, error) {
+	log.Printf("StringDecrypt: Attempting decompression, data length: %d", len(encryptedString))
+
+	// Method 1: Try direct LZ-string decompression (data sudah didecrypt di response.go)
+	if result, err := lzstring.DecompressFromEncodedURIComponent(encryptedString); err == nil && len(result) > 0 {
+		log.Printf("StringDecrypt: Direct decompression successful")
+		return result, nil
+	}
+
+	// Method 2: Try other LZ-string methods
+	if result, err := lzstring.DecompressFromBase64(encryptedString); err == nil && len(result) > 0 {
+		log.Printf("StringDecrypt: Base64 decompression successful")
+		return result, nil
+	}
+
+	// Method 3: If all fail, return the original string
+	log.Printf("StringDecrypt: All decompression failed, returning original data")
+	return encryptedString, nil
+}
+
+func RemovePKCS7Padding(data []byte) []byte {
+	if len(data) == 0 {
+		return data
+	}
+
+	paddingLength := int(data[len(data)-1])
+
+	// Validasi padding length
+	if paddingLength > len(data) || paddingLength == 0 || paddingLength > 16 {
+		log.Printf("RemovePKCS7Padding: Invalid padding length: %d, data length: %d", paddingLength, len(data))
+		// Coba kembalikan data tanpa byte terakhir jika padding tampak salah
+		if len(data) > 1 {
+			return data[:len(data)-1]
+		}
+		return data
+	}
+
+	// Verify all padding bytes are correct
+	paddingStart := len(data) - paddingLength
+	for i := paddingStart; i < len(data); i++ {
+		if data[i] != byte(paddingLength) {
+			log.Printf("RemovePKCS7Padding: Invalid padding byte at position %d, expected %d, got %d", i, paddingLength, data[i])
+			// Jika padding tidak valid, coba cari padding yang benar
+			return findValidPadding(data)
+		}
+	}
+
+	result := data[:paddingStart]
+	log.Printf("RemovePKCS7Padding: Successfully removed %d padding bytes", paddingLength)
+	return result
+}
+
+// Fungsi baru untuk mencari padding yang valid
+func findValidPadding(data []byte) []byte {
+	dataLen := len(data)
+
+	// Coba berbagai kemungkinan padding length (1-16)
+	for padLen := 1; padLen <= 16 && padLen <= dataLen; padLen++ {
+		valid := true
+		for i := dataLen - padLen; i < dataLen; i++ {
+			if data[i] != byte(padLen) {
+				valid = false
+				break
+			}
+		}
+		if valid {
+			log.Printf("RemovePKCS7Padding: Found valid padding of length %d", padLen)
+			return data[:dataLen-padLen]
+		}
+	}
+
+	log.Printf("RemovePKCS7Padding: No valid padding found, returning original data")
+	return data
+}

internal/helpers/bpjs/pkcs7.go

@@ -0,0 +1,25 @@
+package helper
+
+import "errors"
+
+func Pad(buf []byte, size int) ([]byte, error) {
+	bufLen := len(buf)
+	padLen := size - bufLen%size
+	padded := make([]byte, bufLen+padLen)
+	copy(padded, buf)
+	for i := 0; i < padLen; i++ {
+		padded[bufLen+i] = byte(padLen)
+	}
+	return padded, nil
+}
+
+func Unpad(padded []byte, size int) ([]byte, error) {
+	if len(padded)%size != 0 {
+		return nil, errors.New("pkcs7: Padded value wasn't in correct size.")
+	}
+
+	bufLen := len(padded) - int(padded[len(padded)-1])
+	buf := make([]byte, bufLen)
+	copy(buf, padded[:bufLen])
+	return buf, nil
+}