GMSMHiAn

1fun hashAndSavePasswordHash(context: Context, clearPassword: String) {
2    val digest = MessageDigest.getInstance("SHA-1")
3    val result = digest.digest(clearPassword.toByteArray(Charsets.UTF_8))
4    val sb = StringBuilder()
5    for (b in result) {
6        sb.append(String.format("%02X", b))
7    }
8    val hashedPassword = sb.toString()
9    val sharedPref = PreferenceManager.getDefaultSharedPreferences(context)
10    val editor = sharedPref.edit()
11    editor.putString("password_hash", hashedPassword)
12    editor.apply()
13}
14
15fun getSavedPasswordHash(context: Context): String {
16    val sharedPref = PreferenceManager.getDefaultSharedPreferences(context)
17    return if (sharedPref.contains("password_hash"))
18        sharedPref.getString("password_hash", "")!!
19    else
20        ""
21}
22
23fun getHashForString(context: Context, stringToHash: String): String {
24    val digest = MessageDigest.getInstance("SHA-1")
25    val result = digest.digest(stringToHash.toByteArray(Charsets.UTF_8))
26    val sb = StringBuilder()
27    for (b in result) {
28        sb.append(String.format("%02X", b))
29    }
30    val hashedString = sb.toString()
31    return hashedString
32}
33
34fun encryptAndSavePassword(context:Context, strToEncrypt: String): ByteArray {
35    val plainText = strToEncrypt.toByteArray(Charsets.UTF_8)
36    val keygen = KeyGenerator.getInstance("AES")
37    keygen.init(256)
38    val key = keygen.generateKey()
39    saveSecretKey(context, key)
40    val cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING")
41    cipher.init(Cipher.ENCRYPT_MODE, key)
42    val cipherText = cipher.doFinal(plainText)
43    saveInitializationVector(context, cipher.iv)
44
45    val baos = ByteArrayOutputStream()
46    val oos = ObjectOutputStream(baos)
47    oos.writeObject(cipherText)
48    val strToSave = String(android.util.Base64.encode(baos.toByteArray(), android.util.Base64.DEFAULT))
49    val sharedPref = PreferenceManager.getDefaultSharedPreferences(context)
50    val editor = sharedPref.edit()
51    editor.putString("encrypted_password", strToSave)
52    editor.apply()
53
54    return cipherText
55}
56
57fun getDecryptedPassword(context: Context): String {
58    val sharedPref = PreferenceManager.getDefaultSharedPreferences(context)
59    val strEncryptedPassword = sharedPref.getString("encrypted_password", "")
60    val bytes = android.util.Base64.decode(strEncryptedPassword, android.util.Base64.DEFAULT)
61    val ois = ObjectInputStream(ByteArrayInputStream(bytes))
62    val passwordToDecryptByteArray = ois.readObject() as ByteArray
63    val decryptedPasswordByteArray = decrypt(context, passwordToDecryptByteArray)
64
65    val decryptedPassword = StringBuilder()
66    for (b in decryptedPasswordByteArray) {
67        decryptedPassword.append(b.toChar())
68    }
69
70    return decryptedPassword.toString()
71}
72
73private fun decrypt(context:Context, dataToDecrypt: ByteArray): ByteArray {
74    val cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING")
75    val ivSpec = IvParameterSpec(getSavedInitializationVector(context))
76    cipher.init(Cipher.DECRYPT_MODE, getSavedSecretKey(context), ivSpec)
77    val cipherText = cipher.doFinal(dataToDecrypt)
78
79    /*val sb = StringBuilder()
80    for (b in cipherText) {
81        sb.append(b.toChar())
82    }
83    Toast.makeText(context, "dbg decrypted = [" + sb.toString() + "]", Toast.LENGTH_LONG).show()*/
84
85    return cipherText
86}
87
88private fun saveSecretKey(context:Context, secretKey: SecretKey) {
89    val baos = ByteArrayOutputStream()
90    val oos = ObjectOutputStream(baos)
91    oos.writeObject(secretKey)
92    val strToSave = String(android.util.Base64.encode(baos.toByteArray(), android.util.Base64.DEFAULT))
93    val sharedPref = PreferenceManager.getDefaultSharedPreferences(context)
94    val editor = sharedPref.edit()
95    editor.putString("secret_key", strToSave)
96    editor.apply()
97}
98
99private fun getSavedSecretKey(context: Context): SecretKey {
100    val sharedPref = PreferenceManager.getDefaultSharedPreferences(context)
101    val strSecretKey = sharedPref.getString("secret_key", "")
102    val bytes = android.util.Base64.decode(strSecretKey, android.util.Base64.DEFAULT)
103    val ois = ObjectInputStream(ByteArrayInputStream(bytes))
104    val secretKey = ois.readObject() as SecretKey
105    return secretKey
106}
107
108private fun saveInitializationVector(context: Context, initializationVector: ByteArray) {
109    val baos = ByteArrayOutputStream()
110    val oos = ObjectOutputStream(baos)
111    oos.writeObject(initializationVector)
112    val strToSave = String(android.util.Base64.encode(baos.toByteArray(), android.util.Base64.DEFAULT))
113    val sharedPref = PreferenceManager.getDefaultSharedPreferences(context)
114    val editor = sharedPref.edit()
115    editor.putString("initialization_vector", strToSave)
116    editor.apply()
117}
118
119private fun getSavedInitializationVector(context: Context) : ByteArray {
120    val sharedPref = PreferenceManager.getDefaultSharedPreferences(context)
121    val strInitializationVector = sharedPref.getString("initialization_vector", "")
122    val bytes = android.util.Base64.decode(strInitializationVector, android.util.Base64.DEFAULT)
123    val ois = ObjectInputStream(ByteArrayInputStream(bytes))
124    val initializationVector = ois.readObject() as ByteArray
125    return initializationVector
126}