Add serialization for inbound group session

- remove compiler warnings when logs are not enabled
- new getInstanceId() function to refactor code

9 files changed, 242 insertions, 219 deletions

diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_account.cpp b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_account.cpp
index 1a1b360..baa7939 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_account.cpp
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_account.cpp
@@ -119,8 +119,7 @@ JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(initNewAccountJni)(JNIEnv *env, jobject thi
             // create account
             accountRetCode = olm_create_account(accountPtr, (void*)randomBuffPtr, randomSize);
             if(accountRetCode == olm_error()) {
-                const char *errorMsgPtr = olm_account_last_error(accountPtr);
-                LOGE("## initNewAccount(): failure - account creation failed Msg=%s", errorMsgPtr);
+                LOGE("## initNewAccount(): failure - account creation failed Msg=%s", (const char *)olm_account_last_error(accountPtr));
              }
 
             LOGD("## initNewAccount(): success - OLM account created");
@@ -171,8 +170,7 @@ JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(identityKeysJni)(JNIEnv *env, jobject
         {   // retrieve key pairs in identityKeysBytesPtr
             keysResult = olm_account_identity_keys(accountPtr, identityKeysBytesPtr, identityKeysLength);
             if(keysResult == olm_error()) {
-                const char *errorMsgPtr = olm_account_last_error(accountPtr);
-                LOGE("## identityKeys(): failure - error getting identity keys Msg=%s",errorMsgPtr);
+                LOGE("## identityKeys(): failure - error getting identity keys Msg=%s",(const char *)olm_account_last_error(accountPtr));
             }
             else
             {   // allocate the byte array to be returned to java
@@ -253,8 +251,7 @@ JNIEXPORT jint OLM_ACCOUNT_FUNC_DEF(generateOneTimeKeys)(JNIEnv *env, jobject th
             // retrieve key pairs in keysBytesPtr
             result = olm_account_generate_one_time_keys(accountPtr, (size_t)aNumberOfKeys, (void*)randomBufferPtr, randomLength);
             if(result == olm_error()) {
-                const char *errorMsgPtr = olm_account_last_error(accountPtr);
-                LOGE("## generateOneTimeKeys(): failure - error generating one time keys Msg=%s",errorMsgPtr);
+                LOGE("## generateOneTimeKeys(): failure - error generating one time keys Msg=%s",(const char *)olm_account_last_error(accountPtr));
             }
             else
             {
@@ -302,8 +299,7 @@ JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(oneTimeKeysJni)(JNIEnv *env, jobject t
         {   // retrieve key pairs in keysBytesPtr
             keysResult = olm_account_one_time_keys(accountPtr, keysBytesPtr, keysLength);
             if(keysResult == olm_error()) {
-                const char *errorMsgPtr = olm_account_last_error(accountPtr);
-                LOGE("## oneTimeKeysJni(): failure - error getting one time keys Msg=%s",errorMsgPtr);
+                LOGE("## oneTimeKeysJni(): failure - error getting one time keys Msg=%s",(const char *)olm_account_last_error(accountPtr));
             }
             else
             {   // allocate the byte array to be returned to java
@@ -351,8 +347,7 @@ JNIEXPORT jint OLM_ACCOUNT_FUNC_DEF(removeOneTimeKeysForSessionJni)(JNIEnv *env,
         result = olm_remove_one_time_keys(accountPtr, sessionPtr);
         if(result == olm_error())
         {   // the account doesn't have any matching "one time keys"..
-            const char *errorMsgPtr = olm_account_last_error(accountPtr);
-            LOGW("## removeOneTimeKeysForSessionJni(): failure - removing one time keys Msg=%s",errorMsgPtr);
+            LOGW("## removeOneTimeKeysForSessionJni(): failure - removing one time keys Msg=%s",(const char *)olm_account_last_error(accountPtr));
 
             retCode = ERROR_CODE_NO_MATCHING_ONE_TIME_KEYS;
         }
@@ -386,8 +381,7 @@ JNIEXPORT jint OLM_ACCOUNT_FUNC_DEF(markOneTimeKeysAsPublishedJni)(JNIEnv *env,
         result = olm_account_mark_keys_as_published(accountPtr);
         if(result == olm_error())
         {
-            const char *errorMsgPtr = olm_account_last_error(accountPtr);
-            LOGW("## markOneTimeKeysAsPublishedJni(): failure - Msg=%s",errorMsgPtr);
+            LOGW("## markOneTimeKeysAsPublishedJni(): failure - Msg=%s",(const char *)olm_account_last_error(accountPtr));
             retCode = ERROR_CODE_KO;
         }
         else
@@ -448,8 +442,7 @@ JNIEXPORT jstring OLM_ACCOUNT_FUNC_DEF(signMessageJni)(JNIEnv *env, jobject thiz
                                              signatureLength);
                 if(resultSign == olm_error())
                 {
-                    const char *errorMsgPtr = olm_account_last_error(accountPtr);
-                    LOGE("## signMessageJni(): failure - error signing message Msg=%s",errorMsgPtr);
+                    LOGE("## signMessageJni(): failure - error signing message Msg=%s",(const char *)olm_account_last_error(accountPtr));
                 }
                 else
                 {
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.cpp b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.cpp
index d10a05b..810d62c 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.cpp
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.cpp
@@ -38,7 +38,7 @@ JNIEXPORT void OLM_INBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env
     LOGD(" ## releaseSessionJni(): sessionPtr=%p",sessionPtr);
 
     size_t retCode = olm_clear_inbound_group_session(sessionPtr);
-    LOGD(" ## releaseSessionJni(): clear_inbound_group_session=%lu",retCode);
+    LOGI(" ## releaseSessionJni(): clear_inbound_group_session=%lu",retCode);
 
     LOGD(" ## releaseSessionJni(): free IN");
     free(sessionPtr);
@@ -52,26 +52,26 @@ JNIEXPORT void OLM_INBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env
 * to make the cast (OlmInboundGroupSession* => jlong) platform independent.
 * @return the initialized OlmInboundGroupSession* instance if init succeed, NULL otherwise
 **/
-JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(initNewSessionJni)(JNIEnv *env, jobject thiz)
+JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz)
 {
     OlmInboundGroupSession* sessionPtr = NULL;
     size_t sessionSize = 0;
 
-    LOGD("## initNewSessionJni(): inbound group session IN");
+    LOGD("## createNewSessionJni(): inbound group session IN");
     sessionSize = olm_inbound_group_session_size();
 
     if(0 == sessionSize)
     {
-        LOGE(" ## initNewSessionJni(): failure - inbound group session size = 0");
+        LOGE(" ## createNewSessionJni(): failure - inbound group session size = 0");
     }
     else if(NULL != (sessionPtr=(OlmInboundGroupSession*)malloc(sessionSize)))
     {
       sessionPtr = olm_inbound_group_session(sessionPtr);
-      LOGD(" ## initNewSessionJni(): success - inbound group session size=%lu",sessionSize);
+      LOGD(" ## createNewSessionJni(): success - inbound group session size=%lu",sessionSize);
     }
     else
     {
-      LOGE(" ## initNewSessionJni(): failure - inbound group session OOM");
+      LOGE(" ## createNewSessionJni(): failure - inbound group session OOM");
     }
 
     return (jlong)(intptr_t)sessionPtr;
@@ -160,8 +160,7 @@ JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIEn
             size_t result = olm_inbound_group_session_id(sessionPtr, sessionIdPtr, lengthSessionId);
             if (result == olm_error())
             {
-                const char *errorMsgPtr = olm_inbound_group_session_last_error(sessionPtr);
-                LOGE(" ## sessionIdentifierJni(): failure - get inbound group session identifier failure Msg=%s",errorMsgPtr);
+                LOGE(" ## sessionIdentifierJni(): failure - get inbound group session identifier failure Msg=%s",(const char *)olm_inbound_group_session_last_error(sessionPtr));
             }
             else
             {
@@ -221,8 +220,7 @@ JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *
                                                                                encryptedMsgLength);
             if(maxPlainTextLength == olm_error())
             {
-                const char *errorMsgPtr = olm_inbound_group_session_last_error(sessionPtr);
-                LOGE(" ## decryptMessageJni(): failure - olm_group_decrypt_max_plaintext_length Msg=%s",errorMsgPtr);
+                LOGE(" ## decryptMessageJni(): failure - olm_group_decrypt_max_plaintext_length Msg=%s",(const char *)olm_inbound_group_session_last_error(sessionPtr));
             }
             else
             {
@@ -240,8 +238,7 @@ JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *
                                                            maxPlainTextLength);
                 if(plaintextLength == olm_error())
                 {
-                    const char *errorMsgPtr = olm_inbound_group_session_last_error(sessionPtr);
-                    LOGE(" ## decryptMessageJni(): failure - olm_group_decrypt Msg=%s",errorMsgPtr);
+                    LOGE(" ## decryptMessageJni(): failure - olm_group_decrypt Msg=%s",(const char *)olm_inbound_group_session_last_error(sessionPtr));
                 }
                 else
                 {
@@ -275,4 +272,165 @@ JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *
 }
 
 
+/**
+* Serialize and encrypt session instance into a base64 string.<br>
+* @param aKey key used to encrypt the serialized session data
+* @param[out] aErrorMsg error message set if operation failed
+* @return a base64 string if operation succeed, null otherwise
+**/
+JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(serializeDataWithKeyJni)(JNIEnv *env, jobject thiz, jstring aKey, jobject aErrorMsg)
+{
+    jstring pickledDataRetValue = 0;
+    jclass errorMsgJClass = 0;
+    jmethodID errorMsgMethodId = 0;
+    jstring errorJstring = 0;
+    const char *keyPtr = NULL;
+    void *pickledPtr = NULL;
+    OlmInboundGroupSession* sessionPtr = NULL;
+
+    LOGD("## inbound group session serializeDataWithKeyJni(): IN");
+
+    if(NULL == (sessionPtr = (OlmInboundGroupSession*)getInboundGroupSessionInstanceId(env,thiz)))
+    {
+        LOGE(" ## serializeDataWithKeyJni(): failure - invalid session ptr");
+    }
+    else if(0 == aKey)
+    {
+        LOGE(" ## serializeDataWithKeyJni(): failure - invalid key");
+    }
+    else if(0 == aErrorMsg)
+    {
+        LOGE(" ## serializeDataWithKeyJni(): failure - invalid error object");
+    }
+    else if(0 == (errorMsgJClass = env->GetObjectClass(aErrorMsg)))
+    {
+        LOGE(" ## serializeDataWithKeyJni(): failure - unable to get error class");
+    }
+    else if(0 == (errorMsgMethodId = env->GetMethodID(errorMsgJClass, "append", "(Ljava/lang/String;)Ljava/lang/StringBuffer;")))
+    {
+        LOGE(" ## serializeDataWithKeyJni(): failure - unable to get error method ID");
+    }
+    else if(NULL == (keyPtr = env->GetStringUTFChars(aKey, 0)))
+    {
+        LOGE(" ## serializeDataWithKeyJni(): failure - keyPtr JNI allocation OOM");
+    }
+    else
+    {
+        size_t pickledLength = olm_pickle_inbound_group_session_length(sessionPtr);
+        size_t keyLength = (size_t)env->GetStringUTFLength(aKey);
+        LOGD(" ## serializeDataWithKeyJni(): pickledLength=%lu keyLength=%lu",pickledLength, keyLength);
+        LOGD(" ## serializeDataWithKeyJni(): key=%s",(char const *)keyPtr);
+
+        if(NULL == (pickledPtr = (void*)malloc((pickledLength+1)*sizeof(uint8_t))))
+        {
+            LOGE(" ## serializeDataWithKeyJni(): failure - pickledPtr buffer OOM");
+        }
+        else
+        {
+            size_t result = olm_pickle_inbound_group_session(sessionPtr,
+                                                             (void const *)keyPtr,
+                                                              keyLength,
+                                                              (void*)pickledPtr,
+                                                              pickledLength);
+            if(result == olm_error())
+            {
+                const char *errorMsgPtr = olm_inbound_group_session_last_error(sessionPtr);
+                LOGE(" ## serializeDataWithKeyJni(): failure - olm_pickle_outbound_group_session() Msg=%s",errorMsgPtr);
+
+                if(0 != (errorJstring = env->NewStringUTF(errorMsgPtr)))
+                {
+                    env->CallObjectMethod(aErrorMsg, errorMsgMethodId, errorJstring);
+                }
+            }
+            else
+            {
+                // build success output
+                (static_cast<char*>(pickledPtr))[pickledLength] = static_cast<char>('\0');
+                pickledDataRetValue = env->NewStringUTF((const char*)pickledPtr);
+                LOGD(" ## serializeDataWithKeyJni(): success - result=%lu pickled=%s", result, static_cast<char*>(pickledPtr));
+            }
+        }
+    }
+
+    // free alloc
+    if(NULL != keyPtr)
+    {
+     env->ReleaseStringUTFChars(aKey, keyPtr);
+    }
+
+    if(NULL != pickledPtr)
+    {
+        free(pickledPtr);
+    }
+
+    return pickledDataRetValue;
+}
+
+
+JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(initWithSerializedDataJni)(JNIEnv *env, jobject thiz, jstring aSerializedData, jstring aKey)
+{
+    OlmInboundGroupSession* sessionPtr = NULL;
+    jstring errorMessageRetValue = 0;
+    const char *keyPtr = NULL;
+    const char *pickledPtr = NULL;
 
+    LOGD("## initWithSerializedDataJni(): IN");
+
+    if(NULL == (sessionPtr = (OlmInboundGroupSession*)getInboundGroupSessionInstanceId(env,thiz)))
+    {
+        LOGE(" ## initWithSerializedDataJni(): failure - session failure OOM");
+    }
+    else if(0 == aKey)
+    {
+        LOGE(" ## initWithSerializedDataJni(): failure - invalid key");
+    }
+    else if(0 == aSerializedData)
+    {
+        LOGE(" ## initWithSerializedDataJni(): failure - serialized data");
+    }
+    else if(NULL == (keyPtr = env->GetStringUTFChars(aKey, 0)))
+    {
+        LOGE(" ## initWithSerializedDataJni(): failure - keyPtr JNI allocation OOM");
+    }
+    else if(NULL == (pickledPtr = env->GetStringUTFChars(aSerializedData, 0)))
+    {
+        LOGE(" ## initWithSerializedDataJni(): failure - pickledPtr JNI allocation OOM");
+    }
+    else
+    {
+        size_t pickledLength = (size_t)env->GetStringUTFLength(aSerializedData);
+        size_t keyLength = (size_t)env->GetStringUTFLength(aKey);
+        LOGD(" ## initWithSerializedDataJni(): pickledLength=%lu keyLength=%lu",pickledLength, keyLength);
+        LOGD(" ## initWithSerializedDataJni(): key=%s",(char const *)keyPtr);
+        LOGD(" ## initWithSerializedDataJni(): pickled=%s",(char const *)pickledPtr);
+
+        size_t result = olm_unpickle_inbound_group_session(sessionPtr,
+                                                           (void const *)keyPtr,
+                                                           keyLength,
+                                                           (void*)pickledPtr,
+                                                           pickledLength);
+        if(result == olm_error())
+        {
+            const char *errorMsgPtr = olm_inbound_group_session_last_error(sessionPtr);
+            LOGE(" ## initWithSerializedDataJni(): failure - olm_unpickle_inbound_group_session() Msg=%s",errorMsgPtr);
+            errorMessageRetValue = env->NewStringUTF(errorMsgPtr);
+        }
+        else
+        {
+            LOGD(" ## initWithSerializedDataJni(): success - result=%lu ", result);
+        }
+    }
+
+    // free alloc
+    if(NULL != keyPtr)
+    {
+        env->ReleaseStringUTFChars(aKey, keyPtr);
+    }
+
+    if(NULL != pickledPtr)
+    {
+        env->ReleaseStringUTFChars(aSerializedData, pickledPtr);
+    }
+
+    return errorMessageRetValue;
+}
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.h b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.h
index 1eb8238..897ef46 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.h
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.h
@@ -29,12 +29,16 @@ extern "C" {
 
 // session creation/destruction
 JNIEXPORT void OLM_INBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz);
-JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(initNewSessionJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz);
 
 JNIEXPORT jint OLM_INBOUND_GROUP_SESSION_FUNC_DEF(initInboundGroupSessionWithSessionKeyJni)(JNIEnv *env, jobject thiz, jstring aSessionKey);
 JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIEnv *env, jobject thiz);
 JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobject thiz, jstring aEncryptedMsg);
 
+// serialization
+JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(serializeDataWithKeyJni)(JNIEnv *env, jobject thiz, jstring aKey, jobject aErrorMsg);
+JNIEXPORT jstring OLM_INBOUND_GROUP_SESSION_FUNC_DEF(initWithSerializedDataJni)(JNIEnv *env, jobject thiz, jstring aSerializedData, jstring aKey);
+
 
 #ifdef __cplusplus
 }
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_jni.h b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_jni.h
index 2e31bff..bb718b6 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_jni.h
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_jni.h
@@ -30,16 +30,15 @@
 /* logging macros */
 #define ENABLE_LOGS
 
+#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, TAG, __VA_ARGS__)
+#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, TAG, __VA_ARGS__)
+
 #ifdef ENABLE_LOGS
-    #define LOGV(...) __android_log_print(ANDROID_LOG_VERBOSE, TAG, __VA_ARGS__)
     #define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, TAG, __VA_ARGS__)
     #define LOGW(...) __android_log_print(ANDROID_LOG_WARN, TAG, __VA_ARGS__)
-    #define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, TAG, __VA_ARGS__)
 #else
-    #define LOGV(...)
     #define LOGD(...)
     #define LOGW(...)
-    #define LOGE(...)
 #endif
 
 #define FUNC_DEF(class_name,func_name) JNICALL Java_org_matrix_olm_##class_name##_##func_name
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_jni_helper.cpp b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_jni_helper.cpp
index 174739c..1f0c0df 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_jni_helper.cpp
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_jni_helper.cpp
@@ -63,12 +63,13 @@ bool setRandomInBuffer(uint8_t **aBuffer2Ptr, size_t aRandomSize)
 
 
 /**
-* Read the account instance ID of the calling object.
+* Read the instance ID of the calling object.
 * @param aJniEnv pointer pointing on the JNI function table
 * @param aJavaObject reference to the object on which the method is invoked
+* @param aCallingClass java calling clas name
 * @return the instance ID if operation succeed, -1 if instance ID was not found.
 **/
-jlong getAccountInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
+jlong getInstanceId(JNIEnv* aJniEnv, jobject aJavaObject, const char *aCallingClass)
 {
   jlong instanceId = 0;
   jfieldID instanceIdField;
@@ -77,7 +78,7 @@ jlong getAccountInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
 
   if(NULL!=aJniEnv)
   {
-    requiredClass = aJniEnv->FindClass(CLASS_OLM_ACCOUNT);
+    requiredClass = aJniEnv->FindClass(aCallingClass);
 
     if((0 != requiredClass) && (JNI_TRUE != aJniEnv->IsInstanceOf(aJavaObject, requiredClass)))
     {
@@ -85,78 +86,56 @@ jlong getAccountInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
     }
     else if(0 != (loaderClass=aJniEnv->GetObjectClass(aJavaObject)))
     {
-      if(0 != (instanceIdField=aJniEnv->GetFieldID(loaderClass, "mNativeOlmAccountId", "J")))
+      if(0 != (instanceIdField=aJniEnv->GetFieldID(loaderClass, "mNativeId", "J")))
       {
         instanceId = aJniEnv->GetLongField(aJavaObject, instanceIdField);
         aJniEnv->DeleteLocalRef(loaderClass);
-        LOGD("## getAccountInstanceId(): read from java instanceId=%lld",instanceId);
+        LOGD("## getInstanceId(): read from java instanceId=%lld",instanceId);
       }
       else
       {
-        LOGE("## getAccountInstanceId() ERROR! GetFieldID=null");
+        LOGE("## getInstanceId() ERROR! GetFieldID=null");
       }
     }
     else
     {
-      LOGE("## getAccountInstanceId() ERROR! GetObjectClass=null");
+      LOGE("## getInstanceId() ERROR! GetObjectClass=null");
     }
   }
   else
   {
-    LOGE("## getAccountInstanceId() ERROR! aJniEnv=NULL");
+    LOGE("## getInstanceId() ERROR! aJniEnv=NULL");
   }
-  LOGD("## getAccountInstanceId() success - instanceId=%p (jlong)(intptr_t)instanceId=%lld",(void*)instanceId, (jlong)(intptr_t)instanceId);
+  LOGD("## getInstanceId() success - instanceId=%p (jlong)(intptr_t)instanceId=%lld",(void*)instanceId, (jlong)(intptr_t)instanceId);
   return instanceId;
 }
 
 /**
-* Read the session instance ID of the calling object (aJavaObject).<br>
+* Read the account instance ID of the calling object.
 * @param aJniEnv pointer pointing on the JNI function table
 * @param aJavaObject reference to the object on which the method is invoked
-* @return the instance ID if read succeed, -1 otherwise.
+* @return the instance ID if operation succeed, -1 if instance ID was not found.
 **/
-jlong getSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
+jlong getAccountInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
 {
-  jlong instanceId = 0;
-  jfieldID instanceIdField;
-  jclass loaderClass;
-  jclass requiredClass = 0;
+  jlong instanceId = getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_ACCOUNT);
+  return instanceId;
+}
 
-  if(NULL!=aJniEnv)
-  {
-    requiredClass = aJniEnv->FindClass(CLASS_OLM_SESSION);
 
-    if((0 != requiredClass) && (JNI_TRUE != aJniEnv->IsInstanceOf(aJavaObject, requiredClass)))
-    {
-        LOGE("## getSessionInstanceId() failure - invalid instance of");
-    }
-    else if(0 != (loaderClass=aJniEnv->GetObjectClass(aJavaObject)))
-    {
-      if(0 != (instanceIdField=aJniEnv->GetFieldID(loaderClass, "mNativeOlmSessionId", "J")))
-      {
-        instanceId = aJniEnv->GetLongField(aJavaObject, instanceIdField);
-        aJniEnv->DeleteLocalRef(loaderClass);
-      }
-      else
-      {
-        LOGE("## getSessionInstanceId() ERROR! GetFieldID=null");
-      }
-    }
-    else
-    {
-      LOGE("## getSessionInstanceId() ERROR! GetObjectClass=null");
-    }
-  }
-  else
-  {
-    LOGE("## getSessionInstanceId() ERROR! aJniEnv=NULL");
-  }
 
-  //LOGD("## getSessionInstanceId() success - instanceId=%lld",instanceId);
+/**
+* Read the session instance ID of the calling object (aJavaObject).<br>
+* @param aJniEnv pointer pointing on the JNI function table
+* @param aJavaObject reference to the object on which the method is invoked
+* @return the instance ID if read succeed, -1 otherwise.
+**/
+jlong getSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
+{
+  jlong instanceId = getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_SESSION);
   return instanceId;
 }
 
-
 /**
 * Read the inbound group session instance ID of the calling object (aJavaObject).<br>
 * @param aJniEnv pointer pointing on the JNI function table
@@ -165,41 +144,7 @@ jlong getSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
 **/
 jlong getInboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
 {
-  jlong instanceId = 0;
-  jfieldID instanceIdField;
-  jclass loaderClass;
-  jclass requiredClass = 0;
-
-  if(NULL!=aJniEnv)
-  {
-    requiredClass = aJniEnv->FindClass(CLASS_OLM_INBOUND_GROUP_SESSION);
-
-    if((0 != requiredClass) && (JNI_TRUE != aJniEnv->IsInstanceOf(aJavaObject, requiredClass)))
-    {
-      LOGE("## getInboundGroupSessionInstanceId() failure - invalid instance of");
-    }
-    else if(0 != (loaderClass=aJniEnv->GetObjectClass(aJavaObject)))
-    {
-      if(0 != (instanceIdField=aJniEnv->GetFieldID(loaderClass, "mNativeOlmInboundGroupSessionId", "J")))
-      {
-        instanceId = aJniEnv->GetLongField(aJavaObject, instanceIdField);
-        aJniEnv->DeleteLocalRef(loaderClass);
-      }
-      else
-      {
-        LOGE("## getInboundGroupSessionInstanceId() ERROR! GetFieldID=null");
-      }
-    }
-    else
-    {
-      LOGE("## getInboundGroupSessionInstanceId() ERROR! GetObjectClass=null");
-    }
-  }
-  else
-  {
-    LOGE("## getInboundGroupSessionInstanceId() ERROR! aJniEnv=NULL");
-  }
-
+  jlong instanceId = getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_INBOUND_GROUP_SESSION);
   return instanceId;
 }
 
@@ -212,84 +157,23 @@ jlong getInboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
 **/
 jlong getOutboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
 {
-  jlong instanceId = 0;
-  jfieldID instanceIdField;
-  jclass loaderClass;
-  jclass requiredClass = 0;
-
-  if(NULL!=aJniEnv)
-  {
-    requiredClass = aJniEnv->FindClass(CLASS_OLM_OUTBOUND_GROUP_SESSION);
-
-    if((0 != requiredClass) && (JNI_TRUE != aJniEnv->IsInstanceOf(aJavaObject, requiredClass)))
-    {
-        LOGE("## getOutboundGroupSessionInstanceId() failure - invalid instance of");
-    }
-    else if(0 != (loaderClass=aJniEnv->GetObjectClass(aJavaObject)))
-    {
-      if(0 != (instanceIdField=aJniEnv->GetFieldID(loaderClass, "mNativeOlmOutboundGroupSessionId", "J")))
-      {
-        instanceId = aJniEnv->GetLongField(aJavaObject, instanceIdField);
-        aJniEnv->DeleteLocalRef(loaderClass);
-      }
-      else
-      {
-        LOGE("## getOutboundGroupSessionInstanceId() ERROR! GetFieldID=null");
-      }
-    }
-    else
-    {
-      LOGE("## getOutboundGroupSessionInstanceId() ERROR! GetObjectClass=null");
-    }
-  }
-  else
-  {
-    LOGE("## getOutboundGroupSessionInstanceId() ERROR! aJniEnv=NULL");
-  }
-
+  jlong instanceId = getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_OUTBOUND_GROUP_SESSION);
   return instanceId;
 }
 
+/**
+* Read the utility instance ID of the calling object (aJavaObject).<br>
+* @param aJniEnv pointer pointing on the JNI function table
+* @param aJavaObject reference to the object on which the method is invoked
+* @return the instance ID if read succeed, -1 otherwise.
+**/
 jlong getUtilityInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
 {
-  jlong instanceId = 0;
-  jfieldID instanceIdField;
-  jclass loaderClass;
-  jclass requiredClass = 0;
-
-  if(NULL!=aJniEnv)
-  {
-    requiredClass = aJniEnv->FindClass(CLASS_OLM_UTILITY);
-
-    if((0 != requiredClass) && (JNI_TRUE != aJniEnv->IsInstanceOf(aJavaObject, requiredClass)))
-    {
-        LOGE("## getUtilityInstanceId() failure - invalid instance of");
-    }
-    else if(0 != (loaderClass=aJniEnv->GetObjectClass(aJavaObject)))
-    {
-      if(0 != (instanceIdField=aJniEnv->GetFieldID(loaderClass, "mNativeOlmUtilityId", "J")))
-      {
-        instanceId = aJniEnv->GetLongField(aJavaObject, instanceIdField);
-        aJniEnv->DeleteLocalRef(loaderClass);
-      }
-      else
-      {
-        LOGE("## getUtilityInstanceId() ERROR! GetFieldID=null");
-      }
-    }
-    else
-    {
-      LOGE("## getUtilityInstanceId() ERROR! GetObjectClass=null");
-    }
-  }
-  else
-  {
-    LOGE("## getUtilityInstanceId() ERROR! aJniEnv=NULL");
-  }
-
+  jlong instanceId = getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_UTILITY);
   return instanceId;
 }
 
+
 template <typename T>
 jstring serializeDataWithKey(JNIEnv *env, jobject thiz,
                                 jstring aKey,
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.cpp b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.cpp
index 67bf8bd..8ccd78e 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.cpp
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.cpp
@@ -38,7 +38,7 @@ JNIEXPORT void OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *en
     LOGD(" ## releaseSessionJni(): sessionPtr=%p",sessionPtr);
 
     size_t retCode = olm_clear_outbound_group_session(sessionPtr);
-    LOGD(" ## releaseSessionJni(): clear_outbound_group_session=%lu",retCode);
+    LOGI(" ## releaseSessionJni(): clear_outbound_group_session=%lu",retCode);
 
     LOGD(" ## releaseSessionJni(): free IN");
     free(sessionPtr);
@@ -52,26 +52,26 @@ JNIEXPORT void OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *en
 * to make the cast (OlmOutboundGroupSession* => jlong) platform independent.
 * @return the initialized OlmOutboundGroupSession* instance if init succeed, NULL otherwise
 **/
-JNIEXPORT jlong OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(initNewSessionJni)(JNIEnv *env, jobject thiz)
+JNIEXPORT jlong OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz)
 {
     OlmOutboundGroupSession* sessionPtr = NULL;
     size_t sessionSize = 0;
 
-    LOGD("## initNewSessionJni(): outbound group session IN");
+    LOGD("## createNewSessionJni(): outbound group session IN");
     sessionSize = olm_outbound_group_session_size();
 
     if(0 == sessionSize)
     {
-        LOGE(" ## initNewSessionJni(): failure - outbound group session size = 0");
+        LOGE(" ## createNewSessionJni(): failure - outbound group session size = 0");
     }
     else if(NULL != (sessionPtr=(OlmOutboundGroupSession*)malloc(sessionSize)))
     {
       sessionPtr = olm_outbound_group_session(sessionPtr);
-      LOGD(" ## initNewSessionJni(): success - outbound group session size=%lu",sessionSize);
+      LOGD(" ## createNewSessionJni(): success - outbound group session size=%lu",sessionSize);
     }
     else
     {
-      LOGE(" ## initNewSessionJni(): failure - outbound group session OOM");
+      LOGE(" ## createNewSessionJni(): failure - outbound group session OOM");
     }
 
     return (jlong)(intptr_t)sessionPtr;
@@ -111,8 +111,7 @@ JNIEXPORT jint OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(initOutboundGroupSessionJni)(
 
             size_t sessionResult = olm_init_outbound_group_session(sessionPtr, randomBuffPtr, randomLength);
             if(sessionResult == olm_error()) {
-                const char *errorMsgPtr = olm_outbound_group_session_last_error(sessionPtr);
-                LOGE(" ## initOutboundGroupSessionJni(): failure - init outbound session creation  Msg=%s",errorMsgPtr);
+                LOGE(" ## initOutboundGroupSessionJni(): failure - init outbound session creation  Msg=%s",(const char *)olm_outbound_group_session_last_error(sessionPtr));
             }
             else
             {
@@ -160,8 +159,7 @@ JNIEXPORT jstring OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIE
             size_t result = olm_outbound_group_session_id(sessionPtr, sessionIdPtr, lengthSessionId);
             if (result == olm_error())
             {
-                const char *errorMsgPtr = olm_outbound_group_session_last_error(sessionPtr);
-                LOGE(" ## sessionIdentifierJni(): failure - outbound group session identifier failure Msg=%s",errorMsgPtr);
+                LOGE(" ## sessionIdentifierJni(): failure - outbound group session identifier failure Msg=%s",(const char *)olm_outbound_group_session_last_error(sessionPtr));
             }
             else
             {
@@ -237,8 +235,7 @@ JNIEXPORT jstring OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(sessionKeyJni)(JNIEnv *env
             size_t result = olm_outbound_group_session_key(sessionPtr, sessionKeyPtr, sessionKeyLength);
             if (result == olm_error())
             {
-                const char *errorMsgPtr = olm_outbound_group_session_last_error(sessionPtr);
-                LOGE(" ## sessionKeyJni(): failure - session key failure Msg=%s",errorMsgPtr);
+                LOGE(" ## sessionKeyJni(): failure - session key failure Msg=%s",(const char *)olm_outbound_group_session_last_error(sessionPtr));
             }
             else
             {
@@ -301,8 +298,7 @@ JNIEXPORT jstring OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv
                                                        encryptedMsgLength);
             if(encryptedLength == olm_error())
             {
-                const char *errorMsgPtr = olm_outbound_group_session_last_error(sessionPtr);
-                LOGE(" ## encryptMessageJni(): failure - olm_group_encrypt Msg=%s",errorMsgPtr);
+                LOGE(" ## encryptMessageJni(): failure - olm_group_encrypt Msg=%s",(const char *)olm_outbound_group_session_last_error(sessionPtr));
             }
             else
             {
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.h b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.h
index 22c32a7..4b59b93 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.h
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.h
@@ -29,7 +29,7 @@ extern "C" {
 
 // session creation/destruction
 JNIEXPORT void OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz);
-JNIEXPORT jlong OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(initNewSessionJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz);
 
 JNIEXPORT jint OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(initOutboundGroupSessionJni)(JNIEnv *env, jobject thiz);
 JNIEXPORT jstring OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIEnv *env, jobject thiz);
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_session.cpp b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_session.cpp
index 9f64d2e..cfa132c 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_session.cpp
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_session.cpp
@@ -161,8 +161,7 @@ JNIEXPORT jint OLM_SESSION_FUNC_DEF(initOutboundSessionJni)(JNIEnv *env, jobject
                                                             (void*)randomBuffPtr,
                                                             randomSize);
                 if(sessionResult == olm_error()) {
-                    const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-                    LOGE("## initOutboundSessionJni(): failure - session creation  Msg=%s",errorMsgPtr);
+                    LOGE("## initOutboundSessionJni(): failure - session creation  Msg=%s",(const char *)olm_session_last_error(sessionPtr));
                 }
                 else
                 {
@@ -236,8 +235,7 @@ JNIEXPORT jint OLM_SESSION_FUNC_DEF(initInboundSessionJni)(JNIEnv *env, jobject
 
             sessionResult = olm_create_inbound_session(sessionPtr, accountPtr, (void*)messagePtr , messageLength);
             if(sessionResult == olm_error()) {
-                const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-                LOGE("## initInboundSessionJni(): failure - init inbound session creation  Msg=%s",errorMsgPtr);
+                LOGE("## initInboundSessionJni(): failure - init inbound session creation  Msg=%s",(const char *)olm_session_last_error(sessionPtr));
             }
             else
             {
@@ -302,8 +300,7 @@ JNIEXPORT jint OLM_SESSION_FUNC_DEF(initInboundSessionFromIdKeyJni)(JNIEnv *env,
 
         sessionResult = olm_create_inbound_session_from(sessionPtr, accountPtr, theirIdentityKeyPtr, theirIdentityKeyLength, (void*)messagePtr , messageLength);
         if(sessionResult == olm_error()) {
-            const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-            LOGE("## initInboundSessionFromIdKeyJni(): failure - init inbound session creation  Msg=%s",errorMsgPtr);
+            LOGE("## initInboundSessionFromIdKeyJni(): failure - init inbound session creation  Msg=%s",(const char *)olm_session_last_error(sessionPtr));
         }
         else
         {
@@ -355,8 +352,7 @@ JNIEXPORT jint OLM_SESSION_FUNC_DEF(matchesInboundSessionJni)(JNIEnv *env, jobje
 
         size_t matchResult = olm_matches_inbound_session(sessionPtr, (void*)messagePtr , messageLength);
         if(matchResult == olm_error()) {
-            const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-            LOGE("## matchesInboundSessionJni(): failure - no match  Msg=%s",errorMsgPtr);
+            LOGE("## matchesInboundSessionJni(): failure - no match  Msg=%s",(const char *)olm_session_last_error(sessionPtr));
         }
         else
         {
@@ -416,8 +412,7 @@ JNIEXPORT jint JNICALL OLM_SESSION_FUNC_DEF(matchesInboundSessionFromIdKeyJni)(J
 
         size_t matchResult = olm_matches_inbound_session_from(sessionPtr, (void const *)theirIdentityKeyPtr, identityKeyLength, (void*)messagePtr , messageLength);
         if(matchResult == olm_error()) {
-            const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-            LOGE("## matchesInboundSessionFromIdKeyJni(): failure - no match  Msg=%s",errorMsgPtr);
+            LOGE("## matchesInboundSessionFromIdKeyJni(): failure - no match  Msg=%s",(const char *)olm_session_last_error(sessionPtr));
         }
         else
         {
@@ -529,8 +524,7 @@ JNIEXPORT jint OLM_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobject thiz
                                             encryptedMsgLength);
                 if(result == olm_error())
                 {
-                    const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-                    LOGE("## encryptMessageJni(): failure - Msg=%s",errorMsgPtr);
+                    LOGE("## encryptMessageJni(): failure - Msg=%s",(const char *)olm_session_last_error(sessionPtr));
                 }
                 else
                 {
@@ -542,11 +536,10 @@ JNIEXPORT jint OLM_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobject thiz
 
                     // update message: encryptedMsgPtr => encryptedJstring
                     jstring encryptedJstring = env->NewStringUTF((const char*)encryptedMsgPtr);
-                    size_t encryptedUtfMsgLength = (size_t)env->GetStringUTFLength(encryptedJstring);
                     env->SetObjectField(aEncryptedMsg, encryptedMsgFieldId, (jobject)encryptedJstring);
 
                     retCode = ERROR_CODE_OK;
-                    LOGD("## encryptMessageJni(): success - result=%lu Type=%lu utfLength=%lu encryptedMsg=%s", result, messageType, encryptedUtfMsgLength, (const char*)encryptedMsgPtr);
+                    LOGD("## encryptMessageJni(): success - result=%lu Type=%lu utfLength=%lu encryptedMsg=%s", result, messageType, (size_t)env->GetStringUTFLength(encryptedJstring), (const char*)encryptedMsgPtr);
                 }
             }
         }
@@ -642,8 +635,7 @@ JNIEXPORT jstring OLM_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobject t
 
         if(maxPlainTextLength == olm_error())
         {
-            const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-            LOGE("## decryptMessageJni(): failure - olm_decrypt_max_plaintext_length Msg=%s",errorMsgPtr);
+            LOGE("## decryptMessageJni(): failure - olm_decrypt_max_plaintext_length Msg=%s",(const char *)olm_session_last_error(sessionPtr));
         }
         else
         {
@@ -662,8 +654,7 @@ JNIEXPORT jstring OLM_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobject t
                                                  maxPlainTextLength);
             if(plaintextLength == olm_error())
             {
-                const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-                LOGE("## decryptMessageJni(): failure - olm_decrypt Msg=%s",errorMsgPtr);
+                LOGE("## decryptMessageJni(): failure - olm_decrypt Msg=%s",(const char *)olm_session_last_error(sessionPtr));
             }
             else
             {
@@ -728,8 +719,7 @@ JNIEXPORT jstring OLM_SESSION_FUNC_DEF(getSessionIdentifierJni)(JNIEnv *env, job
 
             if (result == olm_error())
             {
-                const char *errorMsgPtr = olm_session_last_error(sessionPtr);
-                LOGE("## getSessionIdentifierJni(): failure - get session identifier failure Msg=%s",errorMsgPtr);
+                LOGE("## getSessionIdentifierJni(): failure - get session identifier failure Msg=%s",(const char *)olm_session_last_error(sessionPtr));
             }
             else
             {
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_utility.cpp b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_utility.cpp
index 6248d34..e11f7eb 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_utility.cpp
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_utility.cpp
@@ -203,8 +203,7 @@ JNIEXPORT jstring OLM_UTILITY_FUNC_DEF(sha256Jni)(JNIEnv *env, jobject thiz, jst
                                        hashLength);
             if(result == olm_error())
             {
-                const char *errorMsgPtr = olm_utility_last_error(utilityPtr);
-                LOGE("## sha256Jni(): failure - hash creation Msg=%s",errorMsgPtr);
+                LOGE("## sha256Jni(): failure - hash creation Msg=%s",(const char *)olm_utility_last_error(utilityPtr));
             }
             else
             {