Replace spongy with libsignal x509 generation for device transfer.

app/witness-verifications.gradle

@@ -378,18 +378,6 @@ dependencyVerification {
         ['com.klinkerapps:logger:1.0.3',
          '177e325259a8b111ad6745ec10db5861723c99f402222b80629f576f49408541'],
 
-        ['com.madgag.spongycastle:core:1.58.0.0',
-         '199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728'],
-
-        ['com.madgag.spongycastle:pg:1.54.0.0',
-         '3f1011ec280c51434dd94396ec25c8d7876d861c0fb1fa9ae70824eddcda2f8f'],
-
-        ['com.madgag.spongycastle:pkix:1.54.0.0',
-         '721a302f5ce18bf6fff89d514ef224c37b5dd9ca67a16b56fafaea4b24a51482'],
-
-        ['com.madgag.spongycastle:prov:1.58.0.0',
-         '092fd09e7006b0814980513b013d4c2b3ffd24a49a635ab4b2d204bb51af1727'],
-
         ['com.makeramen:roundedimageview:2.1.0',
          '1f5a1865796b308c6cdd114acc6e78408b110f0a62fc63553278fbeacd489cd1'],
 

device-transfer/lib/build.gradle

@@ -13,7 +13,6 @@ android {
     defaultConfig {
         minSdkVersion MINIMUM_SDK
         targetSdkVersion TARGET_SDK
-        consumerProguardFiles 'lib-proguard-rules.pro'
     }
 
     compileOptions {
@@ -29,16 +28,7 @@ dependencyVerification {
 dependencies {
     implementation 'androidx.appcompat:appcompat:1.2.0'
     implementation project(':core-util')
-    implementation 'com.madgag.spongycastle:core:1.58.0.0'
+    implementation 'org.whispersystems:signal-client-java:0.5.1'
-    implementation('com.madgag.spongycastle:prov:1.58.0.0') {
-        exclude group: 'junit'
-    }
-    implementation('com.madgag.spongycastle:pkix:1.54.0.0') {
-        exclude group: 'junit'
-    }
-    implementation('com.madgag.spongycastle:pg:1.54.0.0') {
-        exclude group: 'junit'
-    }
     api 'org.greenrobot:eventbus:3.0.0'
 
     testImplementation 'junit:junit:4.12'

device-transfer/lib/lib-proguard-rules.pro

@@ -1,8 +0,0 @@
--keep class org.spongycastle.jcajce.provider.digest.SHA256** {*;}
--keepclassmembers class org.spongycastle.jcajce.provider.digest.SHA256** {*;}
-
--keep class org.spongycastle.jcajce.provider.asymmetric.RSA**
--keepclassmembers class org.spongycastle.jcajce.provider.asymmetric.RSA** {*;}
-
--keep class org.spongycastle.jcajce.provider.asymmetric.rsa.DigestSignatureSpi** {*;}
--keepclassmembers class org.spongycastle.jcajce.provider.asymmetric.rsa.DigestSignatureSpi** {*;}

device-transfer/lib/src/main/java/org/signal/devicetransfer/SelfSignedIdentity.java

@@ -3,32 +3,22 @@ package org.signal.devicetransfer;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import org.spongycastle.asn1.x500.X500Name;
+import org.signal.libsignal.devicetransfer.DeviceTransferKey;
-import org.spongycastle.asn1.x500.X500NameBuilder;
-import org.spongycastle.asn1.x500.style.BCStyle;
-import org.spongycastle.asn1.x509.SubjectPublicKeyInfo;
-import org.spongycastle.cert.X509CertificateHolder;
-import org.spongycastle.cert.X509v3CertificateBuilder;
-import org.spongycastle.jce.provider.BouncyCastleProvider;
-import org.spongycastle.operator.ContentSigner;
-import org.spongycastle.operator.OperatorCreationException;
-import org.spongycastle.operator.jcajce.JcaContentSignerBuilder;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
-import java.math.BigInteger;
 import java.security.GeneralSecurityException;
-import java.security.KeyPair;
+import java.security.KeyFactory;
-import java.security.KeyPairGenerator;
 import java.security.KeyStore;
+import java.security.NoSuchAlgorithmException;
 import java.security.PrivateKey;
 import java.security.SecureRandom;
-import java.security.Security;
 import java.security.cert.Certificate;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
-import java.util.Date;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.PKCS8EncodedKeySpec;
 
 import javax.net.ssl.KeyManagerFactory;
 import javax.net.ssl.SSLContext;
@@ -43,24 +33,19 @@ import javax.net.ssl.X509TrustManager;
 final class SelfSignedIdentity {
 
   private static final String KEY_GENERATION_ALGORITHM = "RSA";
-  private static final int    KEY_SIZE                 = 4096;
   private static final String SSL_CONTEXT_PROTOCOL     = "TLS";
   private static final String CERTIFICATE_TYPE         = "X509";
   private static final String KEYSTORE_TYPE            = "BKS";
-  private static final String SIGNATURE_ALGORITHM      = "SHA256WithRSAEncryption";
 
   private SelfSignedIdentity() { }
 
   public static @NonNull SelfSignedKeys create() throws KeyGenerationFailedException {
     try {
-      KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_GENERATION_ALGORITHM);
+      DeviceTransferKey key = new DeviceTransferKey();
-      keyPairGenerator.initialize(KEY_SIZE);
+      byte[]     x509       = key.generateCertificate("SignalTransfer", 1);
-
+      PrivateKey privateKey = KeyFactory.getInstance(KEY_GENERATION_ALGORITHM).generatePrivate(new PKCS8EncodedKeySpec(key.keyMaterial()));
-      KeyPair               keyPair = keyPairGenerator.generateKeyPair();
+      return new SelfSignedKeys(x509, privateKey);
-      X509CertificateHolder x509    = createX509(keyPair);
+    } catch (InvalidKeySpecException | NoSuchAlgorithmException e) {
-
-      return new SelfSignedKeys(x509.getEncoded(), keyPair.getPrivate());
-    } catch (GeneralSecurityException | OperatorCreationException | IOException e) {
       throw new KeyGenerationFailedException(e);
     }
   }
@@ -73,7 +58,7 @@ final class SelfSignedIdentity {
 
     KeyStore keyStore = KeyStore.getInstance(KEYSTORE_TYPE);
     keyStore.load(null);
-    keyStore.setKeyEntry("client", keys.getPrivateKey(), null, new Certificate[]{certificate});
+    keyStore.setKeyEntry("client", keys.getPrivateKey(), null, new Certificate[] { certificate });
 
     KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
     keyManagerFactory.init(keyStore, null);
@@ -88,40 +73,10 @@ final class SelfSignedIdentity {
       throws GeneralSecurityException
   {
     SSLContext sslContext = SSLContext.getInstance(SSL_CONTEXT_PROTOCOL);
-    sslContext.init(null, new TrustManager[]{trustManager}, new SecureRandom());
+    sslContext.init(null, new TrustManager[] { trustManager }, new SecureRandom());
     return sslContext.getSocketFactory();
   }
 
-  private static @NonNull X509CertificateHolder createX509(@NonNull KeyPair keyPair) throws OperatorCreationException {
-    Date startDate = new Date(System.currentTimeMillis() - 24 * 60 * 60 * 1000);
-    Date endDate   = new Date(System.currentTimeMillis() + 24 * 60 * 60 * 1000);
-
-    X500NameBuilder nameBuilder = new X500NameBuilder(BCStyle.INSTANCE);
-    nameBuilder.addRDN(BCStyle.C, "United States");
-    nameBuilder.addRDN(BCStyle.ST, "California");
-    nameBuilder.addRDN(BCStyle.L, "San Francisco");
-    nameBuilder.addRDN(BCStyle.O, "Signal Foundation");
-    nameBuilder.addRDN(BCStyle.CN, "SignalTransfer");
-
-    X500Name             x500Name             = nameBuilder.build();
-    BigInteger           serialNumber         = BigInteger.valueOf(new SecureRandom().nextLong()).abs();
-    SubjectPublicKeyInfo subjectPublicKeyInfo = SubjectPublicKeyInfo.getInstance(keyPair.getPublic().getEncoded());
-
-    X509v3CertificateBuilder certificateBuilder = new X509v3CertificateBuilder(x500Name,
-                                                                               serialNumber,
-                                                                               startDate,
-                                                                               endDate,
-                                                                               x500Name,
-                                                                               subjectPublicKeyInfo);
-
-    Security.addProvider(new BouncyCastleProvider());
-    ContentSigner signer = new JcaContentSignerBuilder(SIGNATURE_ALGORITHM).setProvider(BouncyCastleProvider.PROVIDER_NAME)
-                                                                           .build(keyPair.getPrivate());
-    Security.removeProvider(BouncyCastleProvider.PROVIDER_NAME);
-
-    return certificateBuilder.build(signer);
-  }
-
   static final class SelfSignedKeys {
     private final byte[]     x509Encoded;
     private final PrivateKey privateKey;

device-transfer/lib/witness-verifications.gradle

@@ -78,19 +78,10 @@ dependencyVerification {
         ['com.google.protobuf:protobuf-javalite:3.10.0',
          '215a94dbe100130295906b531bb72a26965c7ac8fcd9a75bf8054a8ac2abf4b4'],
 
-        ['com.madgag.spongycastle:core:1.58.0.0',
-         '199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728'],
-
-        ['com.madgag.spongycastle:pg:1.54.0.0',
-         '3f1011ec280c51434dd94396ec25c8d7876d861c0fb1fa9ae70824eddcda2f8f'],
-
-        ['com.madgag.spongycastle:pkix:1.54.0.0',
-         '721a302f5ce18bf6fff89d514ef224c37b5dd9ca67a16b56fafaea4b24a51482'],
-
-        ['com.madgag.spongycastle:prov:1.58.0.0',
-         '092fd09e7006b0814980513b013d4c2b3ffd24a49a635ab4b2d204bb51af1727'],
-
         ['org.greenrobot:eventbus:3.0.0',
          '180d4212467df06f2fbc9c8d8a2984533ac79c87769ad883bc421612f0b4e17c'],
+
+        ['org.whispersystems:signal-client-java:0.5.1',
+         '682a8094d38a91c8759071b77177ed8196a7137314fdfbb17e819c9ca57a0397'],
     ]
 }