Downloading extensions from Github Repo. (#1101)

Downloading extensions from Github Repo.

app/src/main/java/eu/kanade/tachiyomi/util/DiskUtil.kt

@@ -10,8 +10,6 @@ import android.support.v4.os.EnvironmentCompat
 import java.io.File
 import java.io.InputStream
 import java.net.URLConnection
-import java.security.MessageDigest
-import java.security.NoSuchAlgorithmException
 
 object DiskUtil {
 
@@ -52,16 +50,7 @@ object DiskUtil {
     }
 
     fun hashKeyForDisk(key: String): String {
-        return try {
-            val bytes = MessageDigest.getInstance("MD5").digest(key.toByteArray())
-            val sb = StringBuilder()
-            bytes.forEach { byte ->
-                sb.append(Integer.toHexString(byte.toInt() and 0xFF or 0x100).substring(1, 3))
-            }
-            sb.toString()
-        } catch (e: NoSuchAlgorithmException) {
-            key.hashCode().toString()
-        }
+        return Hash.md5(key)
     }
 
     fun getDirectorySize(f: File): Long {

app/src/main/java/eu/kanade/tachiyomi/util/Hash.kt

@@ -0,0 +1,42 @@
+package eu.kanade.tachiyomi.util
+
+import java.security.MessageDigest
+
+object Hash {
+
+    private val chars = charArrayOf('0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+            'a', 'b', 'c', 'd', 'e', 'f')
+
+    private val MD5 get() = MessageDigest.getInstance("MD5")
+
+    private val SHA256 get() = MessageDigest.getInstance("SHA-256")
+
+    fun sha256(bytes: ByteArray): String {
+        return encodeHex(SHA256.digest(bytes))
+    }
+
+    fun sha256(string: String): String {
+        return sha256(string.toByteArray())
+    }
+
+    fun md5(bytes: ByteArray): String {
+        return encodeHex(MD5.digest(bytes))
+    }
+
+    fun md5(string: String): String {
+        return md5(string.toByteArray())
+    }
+
+    private fun encodeHex(data: ByteArray): String {
+        val l = data.size
+        val out = CharArray(l shl 1)
+        var i = 0
+        var j = 0
+        while (i < l) {
+            out[j++] = chars[(240 and data[i].toInt()).ushr(4)]
+            out[j++] = chars[15 and data[i].toInt()]
+            i++
+        }
+        return String(out)
+    }
+}