Resolved a few MMS issues.

1) Fixed the "Unsupported Encoding!" problem.

2) Workaround for the Sprint issue, where the MMSC is adding a single
   extra byte to the end of each encrypted message.

3) Fixed the "large blob of base64 text" on encrypted MMS problem.

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

@@ -190,7 +190,21 @@ public class DecryptingQueue {
         synchronized (SessionCipher.CIPHER_LOCK) {
           Log.w("DecryptingQueue", "Decrypting: " + Hex.toString(ciphertextPduBytes));
           SessionCipher cipher = new SessionCipher(context, masterSecret, recipient, new TextTransport());
-          plaintextPduBytes    = cipher.decryptMessage(ciphertextPduBytes);
+          try {
+            plaintextPduBytes = cipher.decryptMessage(ciphertextPduBytes);
+          } catch (InvalidMessageException ime) {
+            // XXX - For some reason, Sprint seems to append a single character to the
+            // end of message text segments.  I don't know why, so here we just try
+            // truncating the message by one if the MAC fails.
+            if (ciphertextPduBytes.length > 2) {
+              Log.w("DecryptingQueue", "Attempting truncated decrypt...");
+              byte[] truncated = new byte[ciphertextPduBytes.length - 1];
+              System.arraycopy(ciphertextPduBytes, 0, truncated, 0, truncated.length);
+              plaintextPduBytes = cipher.decryptMessage(truncated);
+            } else {
+              throw ime;
+            }
+          }
         }
 
         MultimediaMessagePdu plaintextGenericPdu = (MultimediaMessagePdu)new PduParser(plaintextPduBytes).parse();

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

@@ -90,7 +90,8 @@ public class KeyExchangeMessage {
       this.serialized       = messageBody;
 			
       if (messageVersion > Message.SUPPORTED_VERSION)
-        throw new InvalidVersionException("Key exchange with version: " + messageVersion + " but we only support: " + Message.SUPPORTED_VERSION);
+        throw new InvalidVersionException("Key exchange with version: " + messageVersion +
+                                          " but we only support: " + Message.SUPPORTED_VERSION);
 				
       if (messageVersion >= 1)
         keyBytes = Base64.decodeWithoutPadding(messageBody);

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

@@ -23,16 +23,15 @@ import android.util.Log;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpResponse;
 import org.apache.http.StatusLine;
-import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.methods.HttpGet;
 
-import ws.com.google.android.mms.pdu.PduParser;
-import ws.com.google.android.mms.pdu.RetrieveConf;
-
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 
+import ws.com.google.android.mms.pdu.PduParser;
+import ws.com.google.android.mms.pdu.RetrieveConf;
+
 public class MmsDownloadHelper extends MmsCommunication {
 
   private static byte[] makeRequest(Context context, MmsConnectionParameters connectionParameters, String url)

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

@@ -30,13 +30,13 @@ import org.apache.http.entity.ByteArrayEntity;
 import org.thoughtcrime.securesms.service.MmscProcessor;
 import org.thoughtcrime.securesms.util.Util;
 
-import ws.com.google.android.mms.pdu.PduParser;
-import ws.com.google.android.mms.pdu.SendConf;
-
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 
+import ws.com.google.android.mms.pdu.PduParser;
+import ws.com.google.android.mms.pdu.SendConf;
+
 public class MmsSendHelper extends MmsCommunication {
 
   private static byte[] makePost(Context context, MmsConnectionParameters parameters, byte[] mms) throws ClientProtocolException, IOException {

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

@@ -19,8 +19,12 @@ public class PartParser {
         String partText;
 
         try {
-          partText = new String(body.getPart(i).getData(),
-                                CharacterSets.getMimeName(body.getPart(i).getCharset()));
+          String characterSet = CharacterSets.getMimeName(body.getPart(i).getCharset());
+
+          if (characterSet.equals(CharacterSets.MIMENAME_ANY_CHARSET))
+            characterSet = CharacterSets.MIMENAME_ISO_8859_1;
+
+          partText = new String(body.getPart(i).getData(), characterSet);
         } catch (UnsupportedEncodingException e) {
           Log.w("PartParser", e);
           partText = "Unsupported Encoding!";

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

@@ -209,20 +209,21 @@ public class MmsSender extends MmscProcessor {
     EncodedStringValue[] encodedRecipient = pdu.getTo();
     String recipient                      = encodedRecipient[0].getString();
     byte[] pduBytes                       = new PduComposer(context, pdu).make();
-    byte[] encryptedPdu                   = getEncryptedPdu(masterSecret, recipient, pduBytes);
-    Log.w("MmsSendeR", "Got encrypted bytes: " + encryptedPdu.length);
-    PduBody body                          = new PduBody();
-    PduPart part                          = new PduPart();
+    byte[] encryptedPduBytes              = getEncryptedPdu(masterSecret, recipient, pduBytes);
+
+    PduBody body         = new PduBody();
+    PduPart part         = new PduPart();
+    SendReq encryptedPdu = new SendReq(pdu.getPduHeaders(), body);
 
     part.setContentId((System.currentTimeMillis()+"").getBytes());
     part.setContentType(ContentType.TEXT_PLAIN.getBytes());
     part.setName((System.currentTimeMillis()+"").getBytes());
-    part.setData(encryptedPdu);
+    part.setData(encryptedPduBytes);
     body.addPart(part);
-    pdu.setSubject(new EncodedStringValue(WirePrefix.calculateEncryptedMmsSubject()));
-    pdu.setBody(body);
+    encryptedPdu.setSubject(new EncodedStringValue(WirePrefix.calculateEncryptedMmsSubject()));
+    encryptedPdu.setBody(body);
 
-    return pdu;
+    return encryptedPdu;
   }
 
   private void scheduleSendWithMmsRadioAndProxy(SendItem item) {