Generate keys for signing hidden Magisk Manager

app/src/main/java/com/topjohnwu/magisk/Config.kt

@@ -32,8 +32,9 @@ object Config : PreferenceModel, DBConfig {
         const val ROOT_ACCESS = "root_access"
         const val SU_MULTIUSER_MODE = "multiuser_mode"
         const val SU_MNT_NS = "mnt_ns"
-        const val SU_MANAGER = "requester"
         const val SU_FINGERPRINT = "su_fingerprint"
+        const val SU_MANAGER = "requester"
+        const val KEYSTORE = "keystore"
 
         // prefs
         const val SU_REQUEST_TIMEOUT = "su_request_timeout"
@@ -123,6 +124,7 @@ object Config : PreferenceModel, DBConfig {
     var suMultiuserMode by dbSettings(Key.SU_MULTIUSER_MODE, Value.MULTIUSER_MODE_OWNER_ONLY)
     var suFingerprint by dbSettings(Key.SU_FINGERPRINT, false)
     var suManager by dbStrings(Key.SU_MANAGER, "", true)
+    var keyStoreRaw by dbStrings(Key.KEYSTORE, "", true)
 
     // Always return a path in external storage where we can write
     val downloadDirectory get() =

app/src/main/java/com/topjohnwu/magisk/utils/Keygen.kt

@@ -0,0 +1,133 @@
+package com.topjohnwu.magisk.utils
+
+import android.content.pm.PackageManager
+import android.util.Base64
+import android.util.Base64OutputStream
+import com.topjohnwu.magisk.Config
+import com.topjohnwu.magisk.di.koinModules
+import com.topjohnwu.signing.CryptoUtils.readCertificate
+import com.topjohnwu.signing.CryptoUtils.readPrivateKey
+import com.topjohnwu.superuser.internal.InternalUtils
+import org.bouncycastle.asn1.x500.X500Name
+import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter
+import org.bouncycastle.cert.jcajce.JcaX509v3CertificateBuilder
+import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder
+import org.koin.core.context.GlobalContext
+import org.koin.core.context.startKoin
+import timber.log.Timber
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+import java.math.BigInteger
+import java.security.KeyPairGenerator
+import java.security.KeyStore
+import java.security.MessageDigest
+import java.security.PrivateKey
+import java.security.cert.X509Certificate
+import java.util.*
+import java.util.zip.GZIPInputStream
+import java.util.zip.GZIPOutputStream
+
+private interface CertKeyProvider {
+    val cert: X509Certificate
+    val key: PrivateKey
+}
+
+@Suppress("DEPRECATION")
+object Keygen: CertKeyProvider {
+    private const val ALIAS = "magisk"
+    private val PASSWORD = "magisk".toCharArray()
+    private const val TESTKEY_CERT = "61ed377e85d386a8dfee6b864bd85b0bfaa5af81"
+
+    private val start get() = Calendar.getInstance()
+    private val end get() = Calendar.getInstance().apply {
+        add(Calendar.YEAR, 20)
+    }
+
+    override val cert get() = provider.cert
+    override val key get() = provider.key
+
+    private val provider: CertKeyProvider
+
+    class KeyStoreProvider : CertKeyProvider {
+        private val ks by lazy { init() }
+        override val cert by lazy { ks.getCertificate(ALIAS) as X509Certificate }
+        override val key by lazy { ks.getKey(ALIAS, PASSWORD) as PrivateKey }
+    }
+
+    class TestProvider : CertKeyProvider {
+        override val cert by lazy {
+            readCertificate(javaClass.getResourceAsStream("/keys/testkey.x509.pem"))
+        }
+        override val key by lazy {
+            readPrivateKey(javaClass.getResourceAsStream("/keys/testkey.pk8"))
+        }
+    }
+
+    init {
+        // This object could possibly be accessed from an external app
+        // Get context from reflection into Android's framework
+        val context = InternalUtils.getContext()
+        val pm = context.packageManager
+        val info = pm.getPackageInfo(context.packageName, PackageManager.GET_SIGNATURES)
+        val sig = info.signatures[0]
+        val digest = MessageDigest.getInstance("SHA1")
+        val chksum = digest.digest(sig.toByteArray())
+
+        val sb = StringBuilder()
+        for (b in chksum) {
+            sb.append("%02x".format(0xFF and b.toInt()))
+        }
+
+        provider = if (sb.toString() == TESTKEY_CERT) {
+            // The app was signed by the test key, continue to use it (legacy mode)
+            TestProvider()
+        } else {
+            KeyStoreProvider()
+        }
+    }
+
+    private fun init(): KeyStore {
+        GlobalContext.getOrNull() ?: {
+            // Invoked externally, do some basic initialization
+            startKoin {
+                modules(koinModules)
+            }
+            Timber.plant(Timber.DebugTree())
+        }()
+
+        val raw = Config.keyStoreRaw
+        val ks = KeyStore.getInstance("PKCS12")
+        if (raw.isEmpty()) {
+            ks.load(null)
+        } else {
+            GZIPInputStream(ByteArrayInputStream(
+                    Base64.decode(raw, Base64.NO_PADDING or Base64.NO_WRAP)
+            )).use {
+                ks.load(it, PASSWORD)
+            }
+        }
+
+        // Keys already exist
+        if (ks.containsAlias(ALIAS))
+            return ks
+
+        // Generate new private key and certificate
+        val kp = KeyPairGenerator.getInstance("RSA").apply { initialize(2048) }.genKeyPair()
+        val dn = X500Name("CN=Magisk")
+        val builder = JcaX509v3CertificateBuilder(dn,
+                BigInteger.valueOf(start.timeInMillis), start.time, end.time, dn, kp.public)
+        val signer = JcaContentSignerBuilder("SHA256WithRSA").build(kp.private)
+        val cert = JcaX509CertificateConverter().getCertificate(builder.build(signer))
+
+        // Store them into keystore
+        ks.setKeyEntry(ALIAS, kp.private, PASSWORD, arrayOf(cert))
+        val bytes = ByteArrayOutputStream()
+        GZIPOutputStream(Base64OutputStream(bytes, Base64.NO_PADDING or Base64.NO_WRAP)).use {
+            ks.store(it, PASSWORD)
+        }
+        Config.keyStoreRaw = bytes.toString()
+
+        return ks
+    }
+
+}

app/src/main/java/com/topjohnwu/magisk/utils/PatchAPK.kt

@@ -107,7 +107,7 @@ object PatchAPK {
 
             // Write apk changes
             jar.getOutputStream(je).write(xml)
-            SignAPK.sign(jar, FileOutputStream(out).buffered())
+            SignAPK.sign(Keygen.cert, Keygen.key, jar, FileOutputStream(out).buffered())
         } catch (e: Exception) {
             Timber.e(e)
             return false

signing/src/main/java/com/topjohnwu/signing/CryptoUtils.java

@@ -24,7 +24,7 @@ import java.security.spec.PKCS8EncodedKeySpec;
 import java.util.HashMap;
 import java.util.Map;
 
-class CryptoUtils {
+public class CryptoUtils {
 
     static final Map<String, String> ID_TO_ALG;
     static final Map<String, String> ALG_TO_ID;
@@ -81,7 +81,7 @@ class CryptoUtils {
         return new AlgorithmIdentifier(new ASN1ObjectIdentifier(id));
     }
 
-    static X509Certificate readCertificate(InputStream input)
+    public static X509Certificate readCertificate(InputStream input)
             throws IOException, GeneralSecurityException {
         try {
             CertificateFactory cf = CertificateFactory.getInstance("X.509");
@@ -92,7 +92,7 @@ class CryptoUtils {
     }
 
     /** Read a PKCS#8 format private key. */
-    static PrivateKey readPrivateKey(InputStream input)
+    public static PrivateKey readPrivateKey(InputStream input)
             throws IOException, GeneralSecurityException {
         try {
             ByteArrayStream buf = new ByteArrayStream();

signing/src/main/java/com/topjohnwu/signing/SignAPK.java

@@ -30,7 +30,6 @@ import java.io.PrintStream;
 import java.io.RandomAccessFile;
 import java.security.DigestOutputStream;
 import java.security.GeneralSecurityException;
-import java.security.KeyStore;
 import java.security.MessageDigest;
 import java.security.PrivateKey;
 import java.security.cert.CertificateEncodingException;
@@ -61,28 +60,7 @@ public class SignAPK {
     private static final int USE_SHA1 = 1;
     private static final int USE_SHA256 = 2;
 
-    public static void sign(JarMap input, OutputStream output) throws Exception {
+    public static void signAndAdjust(X509Certificate cert, PrivateKey key,
-        sign(SignAPK.class.getResourceAsStream("/keys/testkey.x509.pem"),
-             SignAPK.class.getResourceAsStream("/keys/testkey.pk8"), input, output);
-    }
-
-    public static void sign(InputStream certIs, InputStream keyIs,
-                            JarMap input, OutputStream output) throws Exception {
-        X509Certificate cert = CryptoUtils.readCertificate(certIs);
-        PrivateKey key = CryptoUtils.readPrivateKey(keyIs);
-        sign(cert, key, input, output);
-    }
-
-    public static void sign(InputStream jks, String keyStorePass, String alias, String keyPass,
-                            JarMap input, OutputStream output) throws Exception {
-        KeyStore ks = KeyStore.getInstance("JKS");
-        ks.load(jks, keyStorePass.toCharArray());
-        X509Certificate cert = (X509Certificate) ks.getCertificate(alias);
-        PrivateKey key = (PrivateKey) ks.getKey(alias, keyPass.toCharArray());
-        sign(cert, key, input, output);
-    }
-
-    private static void sign(X509Certificate cert, PrivateKey key,
                                      JarMap input, OutputStream output) throws Exception {
         File temp1 = File.createTempFile("signAPK", null);
         File temp2 = File.createTempFile("signAPK", null);
@@ -103,6 +81,11 @@ public class SignAPK {
         }
     }
 
+    public static void sign(X509Certificate cert, PrivateKey key,
+                            JarMap input, OutputStream output) throws Exception {
+        sign(cert, key, input, output, false);
+    }
+
     private static void sign(X509Certificate cert, PrivateKey key,
                              JarMap input, OutputStream output, boolean minSign) throws Exception {
         int hashes = 0;
@@ -498,11 +481,11 @@ public class SignAPK {
         outputStream.close();
     }
     private static void signFile(Manifest manifest, JarMap inputJar,
-                                 X509Certificate publicKey, PrivateKey privateKey,
+                                 X509Certificate cert, PrivateKey privateKey,
                                  JarOutputStream outputJar)
             throws Exception {
         // Assume the certificate is valid for at least an hour.
-        long timestamp = publicKey.getNotBefore().getTime() + 3600L * 1000;
+        long timestamp = cert.getNotBefore().getTime() + 3600L * 1000;
         // MANIFEST.MF
         JarEntry je = new JarEntry(JarFile.MANIFEST_NAME);
         je.setTime(timestamp);
@@ -512,15 +495,15 @@ public class SignAPK {
         je.setTime(timestamp);
         outputJar.putNextEntry(je);
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        writeSignatureFile(manifest, baos, getDigestAlgorithm(publicKey));
+        writeSignatureFile(manifest, baos, getDigestAlgorithm(cert));
         byte[] signedData = baos.toByteArray();
         outputJar.write(signedData);
         // CERT.{EC,RSA} / CERT#.{EC,RSA}
-        final String keyType = publicKey.getPublicKey().getAlgorithm();
+        final String keyType = cert.getPublicKey().getAlgorithm();
         je = new JarEntry(String.format(CERT_SIG_NAME, keyType));
         je.setTime(timestamp);
         outputJar.putNextEntry(je);
         writeSignatureBlock(new CMSProcessableByteArray(signedData),
-                publicKey, privateKey, outputJar);
+                cert, privateKey, outputJar);
     }
 }

signing/src/main/java/com/topjohnwu/signing/ZipSigner.java

@@ -4,23 +4,61 @@ import org.bouncycastle.jce.provider.BouncyCastleProvider;
 
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
+import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import java.security.NoSuchAlgorithmException;
+import java.security.PrivateKey;
 import java.security.Security;
+import java.security.cert.CertificateException;
+import java.security.cert.X509Certificate;
 
 public class ZipSigner {
 
-    public static void usage() {
+    private static void usage() {
         System.err.println("ZipSigner usage:");
         System.err.println("  zipsigner.jar input.jar output.jar");
         System.err.println("    sign jar with AOSP test keys");
         System.err.println("  zipsigner.jar x509.pem pk8 input.jar output.jar");
         System.err.println("    sign jar with certificate / private key pair");
-        System.err.println("  zipsigner.jar jks keyStorePass keyAlias keyPass input.jar output.jar");
+        System.err.println("  zipsigner.jar keyStore keyStorePass alias keyPass input.jar output.jar");
         System.err.println("    sign jar with Java KeyStore");
         System.exit(2);
     }
 
+    private static void sign(JarMap input, OutputStream output) throws Exception {
+        sign(SignAPK.class.getResourceAsStream("/keys/testkey.x509.pem"),
+                SignAPK.class.getResourceAsStream("/keys/testkey.pk8"), input, output);
+    }
+
+    private static void sign(InputStream certIs, InputStream keyIs,
+                             JarMap input, OutputStream output) throws Exception {
+        X509Certificate cert = CryptoUtils.readCertificate(certIs);
+        PrivateKey key = CryptoUtils.readPrivateKey(keyIs);
+        SignAPK.signAndAdjust(cert, key, input, output);
+    }
+
+    private static void sign(String keyStore, String keyStorePass, String alias, String keyPass,
+                             JarMap in, OutputStream out) throws Exception {
+        KeyStore ks;
+        try {
+            ks = KeyStore.getInstance("JKS");
+            try (InputStream is = new FileInputStream(keyStore)) {
+                ks.load(is, keyStorePass.toCharArray());
+            }
+        } catch (KeyStoreException|IOException|CertificateException|NoSuchAlgorithmException e) {
+            ks = KeyStore.getInstance("PKCS12");
+            try (InputStream is = new FileInputStream(keyStore)) {
+                ks.load(is, keyStorePass.toCharArray());
+            }
+        }
+        X509Certificate cert = (X509Certificate) ks.getCertificate(alias);
+        PrivateKey key = (PrivateKey) ks.getKey(alias, keyPass.toCharArray());
+        SignAPK.signAndAdjust(cert, key, in, out);
+    }
+
     public static void main(String[] args) throws Exception {
         if (args.length != 2 && args.length != 4 && args.length != 6)
             usage();
@@ -30,16 +68,14 @@ public class ZipSigner {
         try (JarMap in = new JarMap(args[args.length - 2], false);
              OutputStream out = new FileOutputStream(args[args.length - 1])) {
             if (args.length == 2) {
-                SignAPK.sign(in, out);
+                sign(in, out);
             } else if (args.length == 4) {
                 try (InputStream cert = new FileInputStream(args[0]);
                      InputStream key = new FileInputStream(args[1])) {
-                    SignAPK.sign(cert, key, in, out);
+                    sign(cert, key, in, out);
                 }
             } else if (args.length == 6) {
-                try (InputStream jks = new FileInputStream(args[0])) {
+                sign(args[0], args[1], args[2], args[3], in, out);
-                    SignAPK.sign(jks, args[1], args[2], args[3], in, out);
-                }
             }
         }
     }