Perbaikan SEP

2025-08-20 04:29:48 +07:00
parent bbecb299a5
commit 773b6589bc
8 changed files with 576 additions and 128 deletions
--- a/internal/helpers/bpjs/lz-string.go
+++ b/internal/helpers/bpjs/lz-string.go
@@ -1,111 +1,46 @@
 package helper

 import (
-	"errors"
-	"math"
-	"unicode/utf8"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/sha256"
+	"encoding/base64"
+	"log"
+
+	lzstring "github.com/daku10/go-lz-string"
 )

-//
-// Decompress uri encoded lz-string
-// http://pieroxy.net/blog/pages/lz-string/index.html
-// https://github.com/pieroxy/lz-string/
-//
+func StringDecrypt(key string, encryptedString string) (string, error) {
+	keyHash := sha256.Sum256([]byte(key))
+	keyHashBytes := keyHash[:]

-// map of "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-$"
-var keyStrUriSafe map[byte]int = map[byte]int{74: 9, 78: 13, 83: 18, 36: 64, 109: 38, 114: 43, 116: 45, 101: 30, 45: 63, 73: 8, 81: 16, 113: 42, 49: 53, 50: 54, 54: 58, 76: 11, 100: 29, 107: 36, 121: 50, 77: 12, 89: 24, 105: 34, 66: 1, 69: 4, 85: 20, 48: 52, 119: 48, 117: 46, 120: 49, 52: 56, 56: 60, 110: 39, 112: 41, 70: 5, 71: 6, 79: 14, 88: 23, 97: 26, 102: 31, 103: 32, 67: 2, 118: 47, 65: 0, 68: 3, 72: 7, 108: 37, 51: 55, 57: 61, 82: 17, 90: 25, 98: 27, 115: 44, 122: 51, 53: 57, 86: 21, 106: 35, 111: 40, 55: 59, 43: 62, 75: 10, 80: 15, 84: 19, 87: 22, 99: 28, 104: 33}
+	iv := keyHashBytes[:16]

-type dataStruct struct {
-	input      string
-	val        int
-	position   int
-	index      int
-	dictionary []string
-	enlargeIn  float64
-	numBits    int
+	encryptedBytes, err := base64.StdEncoding.DecodeString(encryptedString)
+	if err != nil {
+		return "", err
+	}
+
+	block, err := aes.NewCipher(keyHashBytes)
+	if err != nil {
+		return "", err
+	}
+
+	mode := cipher.NewCBCDecrypter(block, iv)
+
+	decrypted := make([]byte, len(encryptedBytes))
+	mode.CryptBlocks(decrypted, encryptedBytes)
+
+	decrypted = RemovePKCS7Padding(decrypted)
+
+	dataResp, err := lzstring.DecompressFromEncodedURIComponent(string(decrypted))
+	if err != nil {
+		log.Fatalf("Error decompress: %v", err)
+	}
+	return dataResp, nil
 }

-func getBaseValue(char byte) int {
-	return keyStrUriSafe[char]
+func RemovePKCS7Padding(data []byte) []byte {
+	paddingLength := int(data[len(data)-1])
+	return data[:len(data)-paddingLength]
 }
-
-// Input is composed of ASCII characters, so accessing it by array has no UTF-8 pb.
-func readBits(nb int, data *dataStruct) int {
-	result := 0
-	power := 1
-	for i := 0; i < nb; i++ {
-		respB := data.val & data.position
-		data.position = data.position / 2
-		if data.position == 0 {
-			data.position = 32
-			data.val = getBaseValue(data.input[data.index])
-			data.index += 1
-		}
-		if respB > 0 {
-			result |= power
-		}
-		power *= 2
-	}
-	return result
-}
-
-func appendValue(data *dataStruct, str string) {
-	data.dictionary = append(data.dictionary, str)
-	data.enlargeIn -= 1
-	if data.enlargeIn == 0 {
-		data.enlargeIn = math.Pow(2, float64(data.numBits))
-		data.numBits += 1
-	}
-}
-
-func getString(last string, data *dataStruct) (string, bool, error) {
-	c := readBits(data.numBits, data)
-	switch c {
-	case 0:
-		str := string(readBits(8, data))
-		appendValue(data, str)
-		return str, false, nil
-	case 1:
-		str := string(readBits(16, data))
-		appendValue(data, str)
-		return str, false, nil
-	case 2:
-		return "", true, nil
-	}
-	if c < len(data.dictionary) {
-		return data.dictionary[c], false, nil
-	}
-	if c == len(data.dictionary) {
-		return concatWithFirstRune(last, last), false, nil
-	}
-	return "", false, errors.New("Bad character encoding.")
-}
-
-// Need to handle UTF-8, so we need to use rune to concatenate
-func concatWithFirstRune(str string, getFirstRune string) string {
-	r, _ := utf8.DecodeRuneInString(getFirstRune)
-	return str + string(r)
-}
-
-func DecompressFromEncodedUriComponent(input string) (string, error) {
-	data := dataStruct{input, getBaseValue(input[0]), 32, 1, []string{"0", "1", "2"}, 5, 2}
-
-	result, isEnd, err := getString("", &data)
-	if err != nil || isEnd {
-		return result, err
-	}
-	last := result
-	data.numBits += 1
-	for {
-		str, isEnd, err := getString(last, &data)
-		if err != nil || isEnd {
-			return result, err
-		}
-
-		result = result + str
-		appendValue(&data, concatWithFirstRune(last, str))
-		last = str
-	}
-
-	return "", errors.New("Unexpected end of buffer reached.")
-}