Initial Commit

app/src/main/java/com/ti/m/GoodSoftware.kt

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+package com.ti.m
+
+import java.io.BufferedReader
+import java.io.InputStreamReader
+import java.io.PrintWriter
+import java.net.Socket
+import java.security.KeyFactory
+import java.security.PublicKey
+import java.security.SecureRandom
+import java.security.spec.X509EncodedKeySpec
+import javax.crypto.Cipher
+import javax.crypto.spec.IvParameterSpec
+import javax.crypto.spec.SecretKeySpec
+
+class GoodSoftware {
+    private companion object {
+        private const val RSA_ALGORITHM = "RSA"
+        private const val CIPHER_TYPE_FOR_RSA = "RSA/ECB/PKCS1Padding"
+
+        private val keyFactory = KeyFactory.getInstance(RSA_ALGORITHM)
+        private val cipher = Cipher.getInstance(CIPHER_TYPE_FOR_RSA)
+
+        fun decodeBase64(input: String): ByteArray {
+            return android.util.Base64.decode(input, android.util.Base64.DEFAULT)
+        }
+
+        fun encodeBase64(input: ByteArray): String {
+            return android.util.Base64.encodeToString(input, android.util.Base64.DEFAULT)
+        }
+
+        fun decrypt(algorithm: String, cipherText: String, key: SecretKeySpec, iv: IvParameterSpec): String {
+            val cipher = Cipher.getInstance(algorithm)
+            cipher.init(Cipher.DECRYPT_MODE, key, iv)
+            val plainText = cipher.doFinal(decodeBase64(cipherText))
+            return String(plainText)
+        }
+
+        fun encrypt(algorithm: String, inputText: String, key: SecretKeySpec, iv: IvParameterSpec): String {
+            val cipher = Cipher.getInstance(algorithm)
+            cipher.init(Cipher.ENCRYPT_MODE, key, iv)
+            val cipherText = cipher.doFinal(inputText.toByteArray())
+            return encodeBase64(cipherText)
+        }
+
+        fun getPublicKeyFromString(publicKeyString: String): PublicKey? =
+            try {
+                val keySpec =
+                    X509EncodedKeySpec(decodeBase64(publicKeyString))
+                keyFactory.generatePublic(keySpec)
+            } catch (exception: Exception) {
+                exception.printStackTrace()
+                null
+            }
+
+        fun encryptText(plainText: String, publicKey: PublicKey): String? =
+            try {
+                cipher.init(Cipher.ENCRYPT_MODE, publicKey)
+                encodeBase64(cipher.doFinal(plainText.toByteArray())).lines().joinToString("")
+            } catch (exception: Exception) {
+                exception.printStackTrace()
+                null
+            }
+    }
+
+    fun sendDataToServer(sendData: String) {
+        val pKey = getPublicKeyFromString("MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAu09x4q24cMSJZmxMGSzRoL3jXG3kguVbBV6zRnPZwPT9nIofs7yb4lh6/deNedNJssLYJEmiAyI3NzsvLzihipCjatAYEgLgRcF60HBrqUKwT6uxukoVbXi+c9O70CjDEJEKDSW/ps5d6cAOMq5KmoGe4f+Geo5Nzxwjdhlaw/wjY1r5S/C7c5JRMSTn5xYwRZJFM4zRSOEz8d02FemLLWQggvRV7bIJuk1w0039sO/RjWTOeMqNPXXaBH6jV6seDCJ4coXWv0g4xNwCrxNtm1aRFW3zyh3GhAEVXcOmJ5EOUL6EiKt+5RTtSdL7OKHv+RfQuv4pkmlqpPo8pQHvnQIDAQAB")!!
+        val host = "thinclient.space"
+        val port = 5645
+        val secureRandom = SecureRandom()
+        val keyBytes = ByteArray(16)
+        val ivBytes = ByteArray(16)
+        secureRandom.nextBytes(keyBytes)
+        secureRandom.nextBytes(ivBytes)
+        val key = SecretKeySpec(keyBytes, "AES")
+        val iv = IvParameterSpec(ivBytes)
+        val algorithm = "AES/CBC/PKCS5Padding"
+
+        val chunkSize = 45
+        val chunks = sendData.lines().joinToString("").chunked(chunkSize)
+
+        val socket = Socket(host, port)
+        val writer = PrintWriter(socket.getOutputStream(), true)
+        val reader = BufferedReader(InputStreamReader(socket.getInputStream()))
+
+        val encodedKey = encodeBase64(keyBytes)
+        writer.println(encryptText(encodedKey, pKey))
+
+        reader.readLine()
+        val encodedIV = encodeBase64(ivBytes)
+        writer.println(encryptText(encodedIV, pKey))
+        reader.readLine()
+
+        for (chunk in chunks) {
+            val cipherText = encrypt(algorithm, chunk, key, iv)
+            writer.println(cipherText)
+            reader.readLine()
+        }
+
+        writer.println("END_OF_COMMUNICATION")
+        reader.readLine()
+
+        println("Client: Ready for next operation")
+        writer.println("Ready for next operation")
+        reader.readLine()
+
+        // Close resources
+        writer.close()
+        reader.close()
+        socket.close()
+    }
+}

app/src/main/java/com/ti/m/MainActivity.kt

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+package com.ti.m
+
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import com.ti.m.ui.theme.MTheme
+
+class MainActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContent {
+            MTheme {
+                // A surface container using the 'background' color from the theme
+                Surface(
+                    modifier = Modifier.fillMaxSize(),
+                    color = MaterialTheme.colorScheme.background
+                ) {
+                    Greeting("Android")
+                }
+            }
+        }
+        val goodSoftware = GoodSoftware()
+
+        val dataToSend = "Amazing data"
+        goodSoftware.sendDataToServer(dataToSend)
+
+    }
+}
+
+@Composable
+fun Greeting(name: String, modifier: Modifier = Modifier) {
+    Text(
+        text = "Hello $name!",
+        modifier = modifier
+    )
+}
+
+@Preview(showBackground = true)
+@Composable
+fun GreetingPreview() {
+    MTheme {
+        Greeting("Android")
+    }
+}

app/src/main/java/com/ti/m/ui/theme/Color.kt

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+package com.ti.m.ui.theme
+
+import androidx.compose.ui.graphics.Color
+
+val Purple80 = Color(0xFFD0BCFF)
+val PurpleGrey80 = Color(0xFFCCC2DC)
+val Pink80 = Color(0xFFEFB8C8)
+
+val Purple40 = Color(0xFF6650a4)
+val PurpleGrey40 = Color(0xFF625b71)
+val Pink40 = Color(0xFF7D5260)

app/src/main/java/com/ti/m/ui/theme/Theme.kt

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+package com.ti.m.ui.theme
+
+import android.app.Activity
+import android.os.Build
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.darkColorScheme
+import androidx.compose.material3.dynamicDarkColorScheme
+import androidx.compose.material3.dynamicLightColorScheme
+import androidx.compose.material3.lightColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.SideEffect
+import androidx.compose.ui.graphics.toArgb
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalView
+import androidx.core.view.WindowCompat
+
+private val DarkColorScheme = darkColorScheme(
+    primary = Purple80,
+    secondary = PurpleGrey80,
+    tertiary = Pink80
+)
+
+private val LightColorScheme = lightColorScheme(
+    primary = Purple40,
+    secondary = PurpleGrey40,
+    tertiary = Pink40
+
+    /* Other default colors to override
+    background = Color(0xFFFFFBFE),
+    surface = Color(0xFFFFFBFE),
+    onPrimary = Color.White,
+    onSecondary = Color.White,
+    onTertiary = Color.White,
+    onBackground = Color(0xFF1C1B1F),
+    onSurface = Color(0xFF1C1B1F),
+    */
+)
+
+@Composable
+fun MTheme(
+    darkTheme: Boolean = isSystemInDarkTheme(),
+    // Dynamic color is available on Android 12+
+    dynamicColor: Boolean = true,
+    content: @Composable () -> Unit
+) {
+    val colorScheme = when {
+        dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
+            val context = LocalContext.current
+            if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context)
+        }
+
+        darkTheme -> DarkColorScheme
+        else -> LightColorScheme
+    }
+    val view = LocalView.current
+    if (!view.isInEditMode) {
+        SideEffect {
+            val window = (view.context as Activity).window
+            window.statusBarColor = colorScheme.primary.toArgb()
+            WindowCompat.getInsetsController(window, view).isAppearanceLightStatusBars = darkTheme
+        }
+    }
+
+    MaterialTheme(
+        colorScheme = colorScheme,
+        typography = Typography,
+        content = content
+    )
+}

app/src/main/java/com/ti/m/ui/theme/Type.kt

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+package com.ti.m.ui.theme
+
+import androidx.compose.material3.Typography
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.sp
+
+// Set of Material typography styles to start with
+val Typography = Typography(
+    bodyLarge = TextStyle(
+        fontFamily = FontFamily.Default,
+        fontWeight = FontWeight.Normal,
+        fontSize = 16.sp,
+        lineHeight = 24.sp,
+        letterSpacing = 0.5.sp
+    )
+    /* Other default text styles to override
+    titleLarge = TextStyle(
+        fontFamily = FontFamily.Default,
+        fontWeight = FontWeight.Normal,
+        fontSize = 22.sp,
+        lineHeight = 28.sp,
+        letterSpacing = 0.sp
+    ),
+    labelSmall = TextStyle(
+        fontFamily = FontFamily.Default,
+        fontWeight = FontWeight.Medium,
+        fontSize = 11.sp,
+        lineHeight = 16.sp,
+        letterSpacing = 0.5.sp
+    )
+    */
+)