clear out plaintext buffers in Android SDK where possible

This commit is contained in:
Hubert Chathi 2018-10-10 15:06:58 -04:00
parent b1130fb77f
commit af86a9a8b8
8 changed files with 52 additions and 10 deletions

View file

@ -25,6 +25,8 @@ import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Arrays;
/**
* Class used to create an inbound <a href="http://matrix.org/docs/guides/e2e_implementation.html#handling-an-m-room-key-event">Megolm session</a>.<br>
* Counter part of the outbound group session {@link OlmOutboundGroupSession}, this class decrypts the messages sent by the outbound side.
@ -236,7 +238,7 @@ public class OlmInboundGroupSession extends CommonSerializeUtils implements Seri
* In case of error, null is returned and an error message description is provided in aErrorMsg.
* @param aEncryptedMsg the message to be decrypted
* @return the decrypted message information
* @exception OlmException teh failure reason
* @exception OlmException the failure reason
*/
public DecryptMessageResult decryptMessage(String aEncryptedMsg) throws OlmException {
DecryptMessageResult result = new DecryptMessageResult();
@ -246,6 +248,7 @@ public class OlmInboundGroupSession extends CommonSerializeUtils implements Seri
if (null != decryptedMessageBuffer) {
result.mDecryptedMessage = new String(decryptedMessageBuffer, "UTF-8");
Arrays.fill(decryptedMessageBuffer, (byte) 0);
}
} catch (Exception e) {
Log.e(LOG_TAG, "## decryptMessage() failed " + e.getMessage());

View file

@ -26,6 +26,8 @@ import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Arrays;
/**
* Class used to create an outbound a <a href="http://matrix.org/docs/guides/e2e_implementation.html#starting-a-megolm-session">Megolm session</a>.<br>
* To send a first message in an encrypted room, the client should start a new outbound Megolm session.
@ -166,7 +168,9 @@ public class OlmOutboundGroupSession extends CommonSerializeUtils implements Ser
if (!TextUtils.isEmpty(aClearMsg)) {
try {
byte[] encryptedBuffer = encryptMessageJni(aClearMsg.getBytes("UTF-8"));
byte[] clearMsgBuffer = aClearMsg.getBytes("UTF-8");
byte[] encryptedBuffer = encryptMessageJni(clearMsgBuffer);
Arrays.fill(clearMsgBuffer, (byte) 0);
if (null != encryptedBuffer) {
retValue = new String(encryptedBuffer , "UTF-8");

View file

@ -18,6 +18,8 @@ package org.matrix.olm;
import android.util.Log;
import java.util.Arrays;
public class OlmPkDecryption {
private static final String LOG_TAG = "OlmPkDecryption";
@ -67,7 +69,10 @@ public class OlmPkDecryption {
}
try {
return new String(decryptJni(aMessage), "UTF-8");
byte[] plaintextBuffer = decryptJni(aMessage);
String plaintext = new String(plaintextBuffer, "UTF-8");
Arrays.fill(plaintextBuffer, (byte) 0);
return plaintext;
} catch (Exception e) {
Log.e(LOG_TAG, "## pkDecrypt(): failed " + e.getMessage());
throw new OlmException(OlmException.EXCEPTION_CODE_PK_DECRYPTION_DECRYPT, e.getMessage());

View file

@ -18,6 +18,8 @@ package org.matrix.olm;
import android.util.Log;
import java.util.Arrays;
public class OlmPkEncryption {
private static final String LOG_TAG = "OlmPkEncryption";
@ -72,7 +74,9 @@ public class OlmPkEncryption {
OlmPkMessage encryptedMsgRetValue = new OlmPkMessage();
try {
byte[] ciphertextBuffer = encryptJni(aPlaintext.getBytes("UTF-8"), encryptedMsgRetValue);
byte[] plaintextBuffer = aPlaintext.getBytes("UTF-8");
byte[] ciphertextBuffer = encryptJni(plaintextBuffer, encryptedMsgRetValue);
Arrays.fill(plaintextBuffer, (byte) 0);
if (null != ciphertextBuffer) {
encryptedMsgRetValue.mCipherText = new String(ciphertextBuffer, "UTF-8");

View file

@ -25,6 +25,8 @@ import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Arrays;
/**
* Session class used to create Olm sessions in conjunction with {@link OlmAccount} class.<br>
* Olm session is used to encrypt data between devices, especially to create Olm group sessions (see {@link OlmOutboundGroupSession} and {@link OlmInboundGroupSession}).<br>
@ -295,7 +297,9 @@ public class OlmSession extends CommonSerializeUtils implements Serializable {
OlmMessage encryptedMsgRetValue = new OlmMessage();
try {
byte[] encryptedMessageBuffer = encryptMessageJni(aClearMsg.getBytes("UTF-8"), encryptedMsgRetValue);
byte[] clearMsgBuffer = aClearMsg.getBytes("UTF-8");
byte[] encryptedMessageBuffer = encryptMessageJni(clearMsgBuffer, encryptedMsgRetValue);
Arrays.fill(clearMsgBuffer, (byte) 0);
if (null != encryptedMessageBuffer) {
encryptedMsgRetValue.mCipherText = new String(encryptedMessageBuffer, "UTF-8");
@ -330,7 +334,10 @@ public class OlmSession extends CommonSerializeUtils implements Serializable {
}
try {
return new String(decryptMessageJni(aEncryptedMsg), "UTF-8");
byte[] plaintextBuffer = decryptMessageJni(aEncryptedMsg);
String plaintext = new String(plaintextBuffer, "UTF-8");
Arrays.fill(plaintextBuffer, (byte) 0);
return plaintext;
} catch (Exception e) {
Log.e(LOG_TAG, "## decryptMessage(): failed " + e.getMessage());
throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_DECRYPT_MESSAGE, e.getMessage());

View file

@ -297,6 +297,7 @@ JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(encryptMessageJni)(JNIE
OlmOutboundGroupSession *sessionPtr = NULL;
jbyte* clearMsgPtr = NULL;
jboolean clearMsgIsCopied = JNI_FALSE;
if (!(sessionPtr = (OlmOutboundGroupSession*)getOutboundGroupSessionInstanceId(env,thiz)))
{
@ -308,7 +309,7 @@ JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(encryptMessageJni)(JNIE
LOGE(" ## encryptMessageJni(): failure - invalid clear message");
errorMessage = "invalid clear message";
}
else if (!(clearMsgPtr = env->GetByteArrayElements(aClearMsgBuffer, NULL)))
else if (!(clearMsgPtr = env->GetByteArrayElements(aClearMsgBuffer, &clearMsgIsCopied)))
{
LOGE(" ## encryptMessageJni(): failure - clear message JNI allocation OOM");
errorMessage = "clear message JNI allocation OOM";
@ -359,6 +360,10 @@ JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(encryptMessageJni)(JNIE
// free alloc
if (clearMsgPtr)
{
if (clearMsgIsCopied)
{
memset(clearMsgPtr, 0, (size_t)env->GetArrayLength(aClearMsgBuffer));
}
env->ReleaseByteArrayElements(aClearMsgBuffer, clearMsgPtr, JNI_ABORT);
}

View file

@ -150,6 +150,7 @@ JNIEXPORT jbyteArray OLM_PK_ENCRYPTION_FUNC_DEF(encryptJni)(
jbyteArray encryptedMsgRet = 0;
const char* errorMessage = NULL;
jbyte *plaintextPtr = NULL;
jboolean plaintextIsCopied = JNI_FALSE;
OlmPkEncryption *encryptionPtr = getPkEncryptionInstanceId(env, thiz);
jclass encryptedMsgJClass = 0;
@ -165,7 +166,7 @@ JNIEXPORT jbyteArray OLM_PK_ENCRYPTION_FUNC_DEF(encryptJni)(
LOGE(" ## pkEncryptJni(): failure - invalid clear message");
errorMessage = "invalid clear message";
}
else if (!(plaintextPtr = env->GetByteArrayElements(aPlaintextBuffer, 0)))
else if (!(plaintextPtr = env->GetByteArrayElements(aPlaintextBuffer, &plaintextIsCopied)))
{
LOGE(" ## pkEncryptJni(): failure - plaintext JNI allocation OOM");
errorMessage = "plaintext JNI allocation OOM";
@ -269,6 +270,10 @@ JNIEXPORT jbyteArray OLM_PK_ENCRYPTION_FUNC_DEF(encryptJni)(
if (plaintextPtr)
{
if (plaintextIsCopied)
{
memset(plaintextPtr, 0, (size_t)env->GetArrayLength(aPlaintextBuffer));
}
env->ReleaseByteArrayElements(aPlaintextBuffer, plaintextPtr, JNI_ABORT);
}
@ -561,6 +566,7 @@ JNIEXPORT jbyteArray OLM_PK_DECRYPTION_FUNC_DEF(decryptJni)(
}
if (plaintextPtr)
{
memset(plaintextPtr, 0, maxPlaintextLength);
free(plaintextPtr);
}
}

View file

@ -472,6 +472,7 @@ JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobjec
OlmSession *sessionPtr = getSessionInstanceId(env, thiz);
jbyte *clearMsgPtr = NULL;
jboolean clearMsgIsCopied = JNI_FALSE;
jclass encryptedMsgJClass = 0;
jfieldID typeMsgFieldId;
@ -490,8 +491,9 @@ JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobjec
else if (!aEncryptedMsg)
{
LOGE("## encryptMessageJni(): failure - invalid encrypted message");
errorMessage = "invalid encrypted message";
}
else if (!(clearMsgPtr = env->GetByteArrayElements(aClearMsgBuffer, 0)))
else if (!(clearMsgPtr = env->GetByteArrayElements(aClearMsgBuffer, &clearMsgIsCopied)))
{
LOGE("## encryptMessageJni(): failure - clear message JNI allocation OOM");
errorMessage = "clear message JNI allocation OOM";
@ -580,6 +582,10 @@ JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobjec
// free alloc
if (clearMsgPtr)
{
if (clearMsgIsCopied)
{
memset(clearMsgPtr, 0, (size_t)env->GetArrayLength(aClearMsgBuffer));
}
env->ReleaseByteArrayElements(aClearMsgBuffer, clearMsgPtr, JNI_ABORT);
}
@ -702,6 +708,8 @@ JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobjec
LOGD(" ## decryptMessageJni(): UTF-8 Conversion - decrypted returnedLg=%lu OK",static_cast<long unsigned int>(plaintextLength));
}
memset(plainTextMsgPtr, 0, maxPlainTextLength);
}
}