Fix CDMA decoding of multipart UTF-16 SMS messages.

Recent changes to support CMAS over CDMA introduced a bug causing
an exception to be thrown when decoding multipart UTF-16 encoded
messages. This change fixes the exception by correctly subtracting
the header size from the number of bytes to decode. It also adds
more robust error handling to try to decode the maximum length
possible instead of throwing an exception if the length is still
larger than the user data length after subtracting the header.

This also fixes a bug in the encoder, which was padding the
UTF-16 user data to 16-bit alignment, which is incorrect (should
be padded to an 8-bit boundary). The code happened to work because
we always generated a UDH that was an even number of bytes
(including length) so the padding was a no-op. The decoder works
correctly.

Bug: 6939151
Change-Id: I4000fa2f4703b39e5ed7e5bd8490828303ef8979

1 files changed, 69 insertions, 20 deletions

diff --git a/tests/telephonytests/src/com/android/internal/telephony/cdma/sms/CdmaSmsTest.java b/tests/telephonytests/src/com/android/internal/telephony/cdma/sms/CdmaSmsTest.java
index bb37b65..850babe 100644
--- a/tests/telephonytests/src/com/android/internal/telephony/cdma/sms/CdmaSmsTest.java
+++ b/tests/telephonytests/src/com/android/internal/telephony/cdma/sms/CdmaSmsTest.java
@@ -17,27 +17,28 @@
 package com.android.internal.telephony.cdma.sms;
 
 import android.telephony.TelephonyManager;
+import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
 
-import com.android.internal.telephony.GsmAlphabet;
+import com.android.internal.telephony.GsmAlphabet.TextEncodingDetails;
 import com.android.internal.telephony.SmsHeader;
 import com.android.internal.telephony.cdma.SmsMessage;
-import com.android.internal.telephony.cdma.sms.BearerData;
-import com.android.internal.telephony.cdma.sms.UserData;
-import com.android.internal.telephony.cdma.sms.CdmaSmsAddress;
-import com.android.internal.telephony.GsmAlphabet.TextEncodingDetails;
-import com.android.internal.util.BitwiseInputStream;
-import com.android.internal.util.BitwiseOutputStream;
 import com.android.internal.util.HexDump;
 
-import android.test.AndroidTestCase;
-import android.test.suitebuilder.annotation.SmallTest;
-
-import android.util.Log;
-
 import java.util.ArrayList;
+import java.util.Arrays;
 
 public class CdmaSmsTest extends AndroidTestCase {
-    private final static String LOG_TAG = "XXX CdmaSmsTest XXX";
+
+    // CJK ideographs, Hiragana, Katakana, full width letters, Cyrillic, etc.
+    private static final String sUnicodeChars = "\u4e00\u4e01\u4e02\u4e03" +
+            "\u4e04\u4e05\u4e06\u4e07\u4e08\u4e09\u4e0a\u4e0b\u4e0c\u4e0d" +
+            "\u4e0e\u4e0f\u3041\u3042\u3043\u3044\u3045\u3046\u3047\u3048" +
+            "\u30a1\u30a2\u30a3\u30a4\u30a5\u30a6\u30a7\u30a8" +
+            "\uff10\uff11\uff12\uff13\uff14\uff15\uff16\uff17\uff18" +
+            "\uff70\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78" +
+            "\u0400\u0401\u0402\u0403\u0404\u0405\u0406\u0407\u0408" +
+            "\u00a2\u00a9\u00ae\u2122";
 
     @SmallTest
     public void testCdmaSmsAddrParsing() throws Exception {
@@ -811,23 +812,51 @@ public class CdmaSmsTest extends AndroidTestCase {
 
     @SmallTest
     public void testUserDataHeaderWithEightCharMsg() throws Exception {
+        encodeDecodeAssertEquals("01234567", 2, 2, false);
+    }
+
+    private void encodeDecodeAssertEquals(String payload, int index, int total,
+            boolean oddLengthHeader) throws Exception {
         BearerData bearerData = new BearerData();
         bearerData.messageType = BearerData.MESSAGE_TYPE_DELIVER;
         bearerData.messageId = 55;
-        SmsHeader.ConcatRef concatRef = new SmsHeader.ConcatRef();
-        concatRef.refNumber = 0xEE;
-        concatRef.msgCount = 2;
-        concatRef.seqNumber = 2;
-        concatRef.isEightBits = true;
         SmsHeader smsHeader = new SmsHeader();
-        smsHeader.concatRef = concatRef;
+        if (oddLengthHeader) {
+            // Odd length header to verify correct UTF-16 header padding
+            SmsHeader.MiscElt miscElt = new SmsHeader.MiscElt();
+            miscElt.id = 0x27;  // reserved for future use; ignored on decode
+            miscElt.data = new byte[]{0x12, 0x34};
+            smsHeader.miscEltList.add(miscElt);
+        } else {
+            // Even length header normally generated for concatenated SMS.
+            SmsHeader.ConcatRef concatRef = new SmsHeader.ConcatRef();
+            concatRef.refNumber = 0xEE;
+            concatRef.msgCount = total;
+            concatRef.seqNumber = index;
+            concatRef.isEightBits = true;
+            smsHeader.concatRef = concatRef;
+        }
+        byte[] encodeHeader = SmsHeader.toByteArray(smsHeader);
+        if (oddLengthHeader) {
+            assertEquals(4, encodeHeader.length);     // 5 bytes with UDH length
+        } else {
+            assertEquals(5, encodeHeader.length);     // 6 bytes with UDH length
+        }
         UserData userData = new UserData();
-        userData.payloadStr = "01234567";
+        userData.payloadStr = payload;
         userData.userDataHeader = smsHeader;
         bearerData.userData = userData;
         byte[] encodedSms = BearerData.encode(bearerData);
         BearerData revBearerData = BearerData.decode(encodedSms);
         assertEquals(userData.payloadStr, revBearerData.userData.payloadStr);
+        assertTrue(revBearerData.hasUserDataHeader);
+        byte[] header = SmsHeader.toByteArray(revBearerData.userData.userDataHeader);
+        if (oddLengthHeader) {
+            assertEquals(4, header.length);     // 5 bytes with UDH length
+        } else {
+            assertEquals(5, header.length);     // 6 bytes with UDH length
+        }
+        assertTrue(Arrays.equals(encodeHeader, header));
     }
 
     @SmallTest
@@ -881,7 +910,27 @@ public class CdmaSmsTest extends AndroidTestCase {
         if (isCdmaPhone) {
             ArrayList<String> fragments = android.telephony.SmsMessage.fragmentText(text2);
             assertEquals(3, fragments.size());
+
+            for (int i = 0; i < 3; i++) {
+                encodeDecodeAssertEquals(fragments.get(i), i + 1, 3, false);
+                encodeDecodeAssertEquals(fragments.get(i), i + 1, 3, true);
+            }
         }
 
+        // Test case for multi-part UTF-16 message.
+        String text3 = sUnicodeChars + sUnicodeChars + sUnicodeChars;
+        ted = SmsMessage.calculateLength(text3, false);
+        assertEquals(3, ted.msgCount);
+        assertEquals(189, ted.codeUnitCount);
+        assertEquals(3, ted.codeUnitSize);
+        if (isCdmaPhone) {
+            ArrayList<String> fragments = android.telephony.SmsMessage.fragmentText(text3);
+            assertEquals(3, fragments.size());
+
+            for (int i = 0; i < 3; i++) {
+                encodeDecodeAssertEquals(fragments.get(i), i + 1, 3, false);
+                encodeDecodeAssertEquals(fragments.get(i), i + 1, 3, true);
+            }
+        }
     }
 }