Simplify access to SecureRandom

This shouldn't matter at all, but it's more "correct," and shows
my age less.

src/org/thoughtcrime/securesms/conversation/ConversationActivity.java

@@ -879,10 +879,9 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
   }
 
   private void handleInviteLink() {
-    try {
     String inviteText;
 
-      boolean a = SecureRandom.getInstance("SHA1PRNG").nextBoolean();
+    boolean a = new SecureRandom().nextBoolean();
     if (a) inviteText = getString(R.string.ConversationActivity_lets_switch_to_signal, "https://sgnl.link/1LoIMUl");
     else   inviteText = getString(R.string.ConversationActivity_lets_use_this_to_chat, "https://sgnl.link/1MF56H1");
 
@@ -895,9 +894,6 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
       intent.putExtra(Intent.EXTRA_TEXT, inviteText);
       startActivity(intent);
     }
-    } catch (NoSuchAlgorithmException e) {
-      throw new AssertionError(e);
-    }
   }
 
   private void handleResetSecureSession() {

src/org/thoughtcrime/securesms/crypto/MasterSecretUtil.java

@@ -264,8 +264,8 @@ public class MasterSecretUtil {
     }
   }
 
-  private static byte[] generateSalt() throws NoSuchAlgorithmException {
+  private static byte[] generateSalt() {
-    SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
+    SecureRandom random = new SecureRandom();
     byte[] salt         = new byte[16];
     random.nextBytes(salt);
 

src/org/thoughtcrime/securesms/database/GroupDatabase.java

@@ -308,13 +308,9 @@ public class GroupDatabase extends Database {
 
 
   public byte[] allocateGroupId() {
-    try {
     byte[] groupId = new byte[16];
-      SecureRandom.getInstance("SHA1PRNG").nextBytes(groupId);
+    new SecureRandom().nextBytes(groupId);
     return groupId;
-    } catch (NoSuchAlgorithmException e) {
-      throw new AssertionError(e);
-    }
   }
 
   public static class Reader implements Closeable {

src/org/thoughtcrime/securesms/database/MmsDatabase.java

@@ -71,7 +71,6 @@ import org.whispersystems.libsignal.util.guava.Optional;
 
 import java.io.Closeable;
 import java.io.IOException;
-import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.util.Collections;
 import java.util.HashMap;
@@ -1279,13 +1278,9 @@ public class MmsDatabase extends MessagingDatabase {
     private final long                 threadId;
 
     public OutgoingMessageReader(OutgoingMediaMessage message, long threadId) {
-      try {
       this.message  = message;
-        this.id = SecureRandom.getInstance("SHA1PRNG").nextLong();
+      this.id       = new SecureRandom().nextLong();
       this.threadId = threadId;
-      } catch (NoSuchAlgorithmException e) {
-        throw new AssertionError(e);
-      }
     }
 
     public MessageRecord getCurrent() {

src/org/thoughtcrime/securesms/database/SmsDatabase.java

@@ -47,7 +47,6 @@ import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.whispersystems.libsignal.util.guava.Optional;
 
 import java.io.IOException;
-import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.util.LinkedList;
 import java.util.List;
@@ -818,13 +817,9 @@ public class SmsDatabase extends MessagingDatabase {
     private final long                threadId;
 
     public OutgoingMessageReader(OutgoingTextMessage message, long threadId) {
-      try {
       this.message  = message;
       this.threadId = threadId;
-        this.id       = SecureRandom.getInstance("SHA1PRNG").nextLong();
+      this.id       = new SecureRandom().nextLong();
-      } catch (NoSuchAlgorithmException e) {
-        throw new AssertionError(e);
-      }
     }
 
     public MessageRecord getCurrent() {

src/org/thoughtcrime/securesms/mms/Slide.java

@@ -144,9 +144,8 @@ public abstract class Slide {
                                                                    boolean voiceNote,
                                                                    boolean quote)
   {
-    try {
     String                 resolvedType    = Optional.fromNullable(MediaUtil.getMimeType(context, uri)).or(defaultMime);
-      String                 fastPreflightId = String.valueOf(SecureRandom.getInstance("SHA1PRNG").nextLong());
+    String                 fastPreflightId = String.valueOf(new SecureRandom().nextLong());
     return new UriAttachment(uri,
                              hasThumbnail ? uri : null,
                              resolvedType,
@@ -159,9 +158,6 @@ public abstract class Slide {
                              voiceNote,
                              quote,
                              caption);
-    } catch (NoSuchAlgorithmException e) {
-      throw new AssertionError(e);
-    }
   }
 
   @Override

src/org/thoughtcrime/securesms/service/WebRtcCallService.java

@@ -415,10 +415,9 @@ public class WebRtcCallService extends Service implements InjectableType,
 
     if (callState != CallState.STATE_IDLE) throw new IllegalStateException("Dialing from non-idle?");
 
-    try {
     this.callState                 = CallState.STATE_DIALING;
     this.recipient                 = getRemoteRecipient(intent);
-      this.callId                    = SecureRandom.getInstance("SHA1PRNG").nextLong();
+    this.callId                    = new SecureRandom().nextLong();
     this.pendingOutgoingIceUpdates = new LinkedList<>();
 
     initializeVideo();
@@ -478,9 +477,6 @@ public class WebRtcCallService extends Service implements InjectableType,
         }
       }
     });
-    } catch (NoSuchAlgorithmException e) {
-      throw new AssertionError(e);
-    }
   }
 
   private void handleResponseMessage(Intent intent) {

src/org/thoughtcrime/securesms/util/Util.java

@@ -456,11 +456,7 @@ public class Util {
   }
 
   public static <T> T getRandomElement(T[] elements) {
-    try {
+    return elements[new SecureRandom().nextInt(elements.length)];
-      return elements[SecureRandom.getInstance("SHA1PRNG").nextInt(elements.length)];
-    } catch (NoSuchAlgorithmException e) {
-      throw new AssertionError(e);
-    }
   }
 
   public static boolean equals(@Nullable Object a, @Nullable Object b) {