aboutsummaryrefslogtreecommitdiff
path: root/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_session.cpp
blob: 93b0658bb203a9fc2433c02dda5b9b68288d8858 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
/*
 * Copyright 2016 OpenMarket Ltd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "olm_session.h"
#include "olm_utility.h"


/**
* Init memory allocation for session creation.
* @return valid memory allocation, NULL otherwise
**/
OlmSession* initializeSessionMemory()
{
    OlmSession* sessionPtr = NULL;
    size_t sessionSize = olm_session_size();

    if(NULL != (sessionPtr=(OlmSession*)malloc(sessionSize)))
    { // init session object
      sessionPtr = olm_session(sessionPtr);
      LOGD("## initializeSessionMemory(): success - OLM session size=%lu",sessionSize);
    }
    else
    {
      LOGE("## initializeSessionMemory(): failure - OOM");
    }

    return sessionPtr;
}

JNIEXPORT void JNICALL Java_org_matrix_olm_OlmSession_releaseSessionJni(JNIEnv *env, jobject thiz)
{
  OlmSession* sessionPtr = NULL;

  if(NULL == (sessionPtr = (OlmSession*)getSessionInstanceId(env,thiz)))
  {
      LOGE("## releaseSessionJni(): failure - invalid Session ptr=NULL");
  }
  else
  { // even if free(NULL) does not crash, a test is performed for debug purpose
    LOGD("## releaseSessionJni(): IN");
    free(sessionPtr);
    LOGD("## releaseSessionJni(): OUT");
  }
}

/**
* Initialize a new session and return it to JAVA side.<br>
* Since a C prt is returned as a jlong, special care will be taken
* to make the cast (OlmSession* => jlong) platform independent.
* @return the initialized OlmSession* instance if init succeed, NULL otherwise
**/
JNIEXPORT jlong JNICALL Java_org_matrix_olm_OlmSession_initNewSessionJni(JNIEnv *env, jobject thiz)
{
    OlmSession* sessionPtr = NULL;

    // init account memory allocation
    if(NULL == (sessionPtr = initializeSessionMemory()))
    {
        LOGE("## initNewSessionJni(): failure - init session OOM");
    }
    else
    {
       LOGD("## initNewSessionJni(): success - OLM session created");
    }

    return (jlong)(intptr_t)sessionPtr;
}

// *********************************************************************
// ********************** OUTBOUND SESSION *****************************
// *********************************************************************
/**
* Create a new in-bound session for sending/receiving messages from an
* incoming PRE_KEY message.<br> The recipient is defined as the entity
* with whom the session is established.
* @param aOlmAccountId account instance
* @param aTheirIdentityKey the identity key of the recipient
* @param aTheirOneTimeKey the one time key of the recipient
* @return ERROR_CODE_OK if operation succeed, ERROR_CODE_KO otherwise
**/
JNIEXPORT jint JNICALL Java_org_matrix_olm_OlmSession_initOutboundSessionJni(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jstring aTheirIdentityKey, jstring aTheirOneTimeKey)
{
    jint retCode = ERROR_CODE_KO;
    OlmSession* sessionPtr = NULL;
    OlmAccount* accountPtr = NULL;
    const char* theirIdentityKeyPtr = NULL;
    const char* theirOneTimeKeyPtr = NULL;
    uint8_t *randomBuffPtr = NULL;
    size_t sessionResult;

    if(NULL == (sessionPtr = (OlmSession*)getSessionInstanceId(env,thiz)))
    {
        LOGE("## initOutboundSessionJni(): failure - invalid Session ptr=NULL");
    }
    else if(NULL == (accountPtr = (OlmAccount*)aOlmAccountId))
    {
        LOGE("## initOutboundSessionJni(): failure - invalid Account ptr=NULL");
    }
    else if((0==aTheirIdentityKey) || (0==aTheirOneTimeKey))
    {
        LOGE("## initOutboundSessionJni(): failure - invalid keys");
    }
    else
    {   // allocate random buffer
        size_t randomSize = olm_create_outbound_session_random_length(sessionPtr);
        if(false == setRandomInBuffer(&randomBuffPtr, randomSize))
        {
            LOGE("## initOutboundSessionJni(): failure - random buffer init");
        }
        else
        {   // convert identity & one time keys to C strings
            if(NULL == (theirIdentityKeyPtr = env->GetStringUTFChars(aTheirIdentityKey, 0)))
            {
                LOGE("## initOutboundSessionJni(): failure - identityKey JNI allocation OOM");
            }
            else if(NULL == (theirOneTimeKeyPtr = env->GetStringUTFChars(aTheirOneTimeKey, 0)))
            {
                LOGE("## initOutboundSessionJni(): failure - one time Key JNI allocation OOM");
            }
            else
            {
                int theirIdentityKeyLength = env->GetStringUTFLength(aTheirIdentityKey);
                int theirOneTimeKeyLength  = env->GetStringUTFLength(aTheirOneTimeKey);
                LOGD("## initOutboundSessionJni(): identityKey=%s oneTimeKey=%s",theirIdentityKeyPtr,theirOneTimeKeyPtr);

                sessionResult = olm_create_outbound_session(sessionPtr,
                                                            accountPtr,
                                                            theirIdentityKeyPtr,
                                                            theirIdentityKeyLength,
                                                            theirOneTimeKeyPtr,
                                                            theirOneTimeKeyLength,
                                                            (void*)randomBuffPtr,
                                                            randomSize);
                if(sessionResult == olm_error()) {
                    const char *errorMsgPtr = olm_session_last_error(sessionPtr);
                    LOGE("## initOutboundSessionJni(): failure - session creation  Msg=%s",errorMsgPtr);
                }
                else
                {
                    retCode = ERROR_CODE_OK;
                    LOGD("## initOutboundSessionJni(): success - result=%ld", sessionResult);
                }
            }
        }
    }

     // **** free mem alloc ***
     if(NULL!= randomBuffPtr)
     {
         free(randomBuffPtr);
     }

     if(NULL!= theirIdentityKeyPtr)
     {
         env->ReleaseStringUTFChars(aTheirIdentityKey, theirIdentityKeyPtr);
     }

     if(NULL!= theirOneTimeKeyPtr)
     {
         env->ReleaseStringUTFChars(aTheirOneTimeKey, theirOneTimeKeyPtr);
     }

    return retCode;
}


// *********************************************************************
// *********************** INBOUND SESSION *****************************
// *********************************************************************
/**
 * Create a new in-bound session for sending/receiving messages from an
 * incoming PRE_KEY message.<br>
 * @param aOlmAccountId account instance
 * @param aOneTimeKeyMsg PRE_KEY message
 * @return ERROR_CODE_OK if operation succeed, ERROR_CODE_KO otherwise
 */
JNIEXPORT jint JNICALL Java_org_matrix_olm_OlmSession_initInboundSessionJni(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jstring aOneTimeKeyMsg)
{
    jint retCode = ERROR_CODE_KO;
    OlmSession *sessionPtr = NULL;
    OlmAccount *accountPtr = NULL;
    size_t sessionResult;

    if(NULL == (sessionPtr = (OlmSession*)getSessionInstanceId(env,thiz)))
    {
        LOGE("## initInboundSessionJni(): failure - invalid Session ptr=NULL");
    }
    else if(NULL == (accountPtr = (OlmAccount*)aOlmAccountId))
    {
        LOGE("## initInboundSessionJni(): failure - invalid Account ptr=NULL");
    }
    else if(0==aOneTimeKeyMsg)
    {
        LOGE("## initOutboundSessionJni(): failure - invalid message");
    }
    else
    {   // convert message to C strings
        const char *messagePtr = NULL;
        if(NULL == (messagePtr = env->GetStringUTFChars(aOneTimeKeyMsg, 0)))
        {
            LOGE("## initInboundSessionJni(): failure - message JNI allocation OOM");
        }
        else
        {
            int messageLength = env->GetStringUTFLength(aOneTimeKeyMsg);
            LOGD("## initInboundSessionJni(): message=%s messageLength=%d",messagePtr,messageLength);

            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);
            }
            else
            {
                retCode = ERROR_CODE_OK;
                LOGD("## initInboundSessionJni(): success - result=%ld", sessionResult);
            }

            // free local alloc
            env->ReleaseStringUTFChars(aOneTimeKeyMsg, messagePtr);
        }
    }
    return retCode;
}

/**
 * Create a new in-bound session for sending/receiving messages from an
 * incoming PRE_KEY message based on the recipient identity key.<br>
 * @param aOlmAccountId account instance
 * @param aTheirIdentityKey the identity key of the recipient
 * @param aOneTimeKeyMsg encrypted message
 * @return ERROR_CODE_OK if operation succeed, ERROR_CODE_KO otherwise
 */
JNIEXPORT jint JNICALL Java_org_matrix_olm_OlmSession_initInboundSessionFromIdKeyJni(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jstring aTheirIdentityKey, jstring aOneTimeKeyMsg)
{
    jint retCode = ERROR_CODE_KO;
    OlmSession *sessionPtr = NULL;
    OlmAccount *accountPtr = NULL;
    const char *messagePtr = NULL;
    const char *theirIdentityKeyPtr = NULL;
    size_t sessionResult;

    if(NULL == (sessionPtr = (OlmSession*)getSessionInstanceId(env,thiz)))
    {
        LOGE("## initInboundSessionFromIdKeyJni(): failure - invalid Session ptr=NULL");
    }
    else if(NULL == (accountPtr = (OlmAccount*)aOlmAccountId))
    {
        LOGE("## initInboundSessionFromIdKeyJni(): failure - invalid Account ptr=NULL");
    }
    else if(0 == aTheirIdentityKey)
    {
        LOGE("## initInboundSessionFromIdKeyJni(): failure - invalid theirIdentityKey");
    }
    else if(0==aOneTimeKeyMsg)
    {
        LOGE("## initOutboundSessionJni(): failure - invalid one time key message");
    }
    else if(NULL == (messagePtr = env->GetStringUTFChars(aOneTimeKeyMsg, 0)))
    {
        LOGE("## initInboundSessionFromIdKeyJni(): failure - message JNI allocation OOM");
    }
    else if(NULL == (theirIdentityKeyPtr = env->GetStringUTFChars(aTheirIdentityKey, 0)))
    {
        LOGE("## initInboundSessionFromIdKeyJni(): failure - theirIdentityKey JNI allocation OOM");
    }
    else
    {
        size_t messageLength = env->GetStringUTFLength(aOneTimeKeyMsg);
        size_t theirIdentityKeyLength = env->GetStringUTFLength(aTheirIdentityKey);

        LOGD("## initInboundSessionFromIdKeyJni(): message=%s messageLength=%lu",messagePtr,messageLength);

        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);
        }
        else
        {
            retCode = ERROR_CODE_OK;
            LOGD("## initInboundSessionFromIdKeyJni(): success - result=%ld", sessionResult);
        }
     }

     // free local alloc
     if(NULL!= messagePtr)
     {
         env->ReleaseStringUTFChars(aOneTimeKeyMsg, messagePtr);
     }
     if(NULL!= theirIdentityKeyPtr)
     {
         env->ReleaseStringUTFChars(aTheirIdentityKey, theirIdentityKeyPtr);
     }

    return retCode;
}

/**
 * Checks if the PRE_KEY message is for this in-bound session.<br>
 * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
 * @param aOneTimeKeyMsg PRE KEY message
 * @return ERROR_CODE_OK if match, ERROR_CODE_KO otherwise
 */
JNIEXPORT jint JNICALL Java_org_matrix_olm_OlmSession_matchesInboundSessionJni(JNIEnv *env, jobject thiz, jstring aOneTimeKeyMsg)
{
    jint retCode = ERROR_CODE_KO;
    OlmSession *sessionPtr = NULL;
    const char *messagePtr = NULL;

    if(NULL == (sessionPtr = (OlmSession*)getSessionInstanceId(env,thiz)))
    {
        LOGE("## matchesInboundSessionJni(): failure - invalid Session ptr=NULL");
    }
    else if(0==aOneTimeKeyMsg)
    {
        LOGE("## matchesInboundSessionJni(): failure - invalid one time key message");
    }
    else if(NULL == (messagePtr = env->GetStringUTFChars(aOneTimeKeyMsg, 0)))
    {
        LOGE("## matchesInboundSessionJni(): failure - one time key JNI allocation OOM");
    }
    else
    {
        size_t messageLength = env->GetStringUTFLength(aOneTimeKeyMsg);

        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);
        }
        else
        {
            retCode = ERROR_CODE_OK;
            LOGD("## matchesInboundSessionJni(): success - result=%ld", matchResult);
        }
    }

    // free local alloc
    if(NULL!= messagePtr)
    {
     env->ReleaseStringUTFChars(aOneTimeKeyMsg, messagePtr);
    }

    return retCode;
}


/**
 * Checks if the PRE_KEY message is for this in-bound session based on the sender identity key.<br>
 * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
 * @param aTheirIdentityKey the identity key of the sender
 * @param aOneTimeKeyMsg PRE KEY message
 * @return ERROR_CODE_OK if match, ERROR_CODE_KO otherwise
 */
JNIEXPORT jint JNICALL Java_org_matrix_olm_OlmSession_matchesInboundSessionFromIdKeyJni(JNIEnv *env, jobject thiz, jstring aTheirIdentityKey, jstring aOneTimeKeyMsg)
{
    jint retCode = ERROR_CODE_KO;
    OlmSession *sessionPtr = NULL;
    const char *messagePtr = NULL;
    const char *theirIdentityKeyPtr = NULL;

    if(NULL == (sessionPtr = (OlmSession*)getSessionInstanceId(env,thiz)))
    {
        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - invalid Session ptr=NULL");
    }
    else if(0 == aTheirIdentityKey)
    {
        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - invalid theirIdentityKey");
    }
    else if(NULL == (theirIdentityKeyPtr = env->GetStringUTFChars(aTheirIdentityKey, 0)))
    {
        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - theirIdentityKey JNI allocation OOM");
    }
    else if(0==aOneTimeKeyMsg)
    {
        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - invalid one time key message");
    }
    else if(NULL == (messagePtr = env->GetStringUTFChars(aOneTimeKeyMsg, 0)))
    {
        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - one time key JNI allocation OOM");
    }
    else
    {
        size_t identityKeyLength = env->GetStringUTFLength(aTheirIdentityKey);
        size_t messageLength = env->GetStringUTFLength(aOneTimeKeyMsg);

        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);
        }
        else
        {
            retCode = ERROR_CODE_OK;
            LOGD("## matchesInboundSessionFromIdKeyJni(): success - result=%lu", matchResult);
        }
    }

    // free local alloc
    if(NULL!= theirIdentityKeyPtr)
    {
     env->ReleaseStringUTFChars(aTheirIdentityKey, theirIdentityKeyPtr);
    }

    if(NULL!= messagePtr)
    {
     env->ReleaseStringUTFChars(aOneTimeKeyMsg, messagePtr);
    }

    return retCode;
}


/**
 * Encrypt a message using the session. to a base64 ciphertext.<br>
 * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
 * @param aTheirIdentityKey the identity key of the sender
 * @param aOneTimeKeyMsg PRE KEY message
 * @return ERROR_CODE_OK if match, ERROR_CODE_KO otherwise
 */
JNIEXPORT jint JNICALL Java_org_matrix_olm_OlmSession_encryptMessageJni(JNIEnv *env, jobject thiz, jstring aClearMsg, jobject aEncryptedMsg)
{
    jint retCode = ERROR_CODE_KO;
    OlmSession *sessionPtr = NULL;
    const char *clearMsgPtr = NULL;
    uint8_t *randomBuffPtr = NULL;
    void *encryptedMsgPtr = NULL;
    jclass encryptedMsgJClass;
    jfieldID encryptedMsgFieldId;
    jfieldID typeMsgFieldId;


    if(NULL == (sessionPtr = (OlmSession*)getSessionInstanceId(env,thiz)))
    {
        LOGE("## encryptMessageJni(): failure - invalid Session ptr=NULL");
    }
    else if(0 == aClearMsg)
    {
        LOGE("## encryptMessageJni(): failure - invalid clear message");
    }
    else if(0 == aEncryptedMsg)
    {
        LOGE("## encryptMessageJni(): failure - invalid clear message");
    }
    else if(NULL == (clearMsgPtr = env->GetStringUTFChars(aClearMsg, 0)))
    {
        LOGE("## encryptMessageJni(): failure - clear message JNI allocation OOM");
    }
    else if(0 == (encryptedMsgJClass = env->GetObjectClass(aEncryptedMsg)))
    {
        LOGE("## encryptMessageJni(): failure - unable to get crypted message class");
    }
    else if(0 == (encryptedMsgFieldId = env->GetFieldID(encryptedMsgJClass,"mCipherText","Ljava/lang/String;")))
    {
        LOGE("## encryptMessageJni(): failure - unable to get message field");
    }
    else if(0 == (typeMsgFieldId = env->GetFieldID(encryptedMsgJClass,"mType","I")))
    {
        LOGE("## encryptMessageJni(): failure - unable to get message type field");
    }
    else
    {
        // compute random buffer
        size_t randomLength = olm_encrypt_random_length(sessionPtr);
        if(false == setRandomInBuffer(&randomBuffPtr, randomLength))
        {
            LOGE("## encryptMessageJni(): failure - random buffer init");
        }
        else
        {
            // alloc buffer for encrypted message
            size_t clearMsgLength = env->GetStringUTFLength(aClearMsg);
            size_t encryptedMsgLength = olm_encrypt_message_length(sessionPtr, clearMsgLength);
            if(NULL == (encryptedMsgPtr = (void*)malloc(encryptedMsgLength*sizeof(void*))))
            {
                LOGE("## encryptMessageJni(): failure - random buffer OOM");
            }

            size_t result = olm_encrypt(sessionPtr,
                                        (void const *)clearMsgPtr,
                                        clearMsgLength,
                                        randomBuffPtr,
                                        randomLength,
                                        encryptedMsgPtr,
                                        encryptedMsgLength);
            if(result == olm_error())
            {
                const char *errorMsgPtr = olm_session_last_error(sessionPtr);
                LOGE("## encryptMessageJni(): failure - Msg=%s",errorMsgPtr);
            }
            else
            {
                // update type: PRE KEY message or normal message
                size_t messageType = olm_encrypt_message_type(sessionPtr);
                env->SetLongField(aEncryptedMsg, typeMsgFieldId, (jlong)messageType);

                // update message
                jstring encryptedStr = env->NewStringUTF((const char*)encryptedMsgPtr);
                env->SetObjectField(aEncryptedMsg, encryptedMsgFieldId, (jobject)encryptedStr);

                retCode = ERROR_CODE_OK;
                LOGD("## encryptMessageJni(): success - result=%lu Type=%lu encryptedMsg=%s", result, messageType, (const char*)encryptedMsgPtr);
            }
        }
    }

    // free alloc
    if(NULL != clearMsgPtr)
    {
     env->ReleaseStringUTFChars(aClearMsg, clearMsgPtr);
    }

    if(NULL != randomBuffPtr)
    {
        free(randomBuffPtr);
    }

    return retCode;
}

/**
* Get the session identifier for this session.
* @return the session identifier if operation succeed, null otherwise
*/
JNIEXPORT jstring JNICALL Java_org_matrix_olm_OlmSession_getSessionIdentifierJni(JNIEnv *env, jobject thiz)
{
    OlmSession *sessionPtr = NULL;
    void *sessionIdPtr = NULL;
    jstring returnValueStr=0;

    // get the size to alloc to contain the id
    size_t lengthSessId = olm_session_id_length(sessionPtr);

    if(NULL == (sessionPtr = (OlmSession*)getSessionInstanceId(env,thiz)))
    {
        LOGE("## getSessionIdentifierJni(): failure - invalid Session ptr=NULL");
    }
    else if(NULL == (sessionIdPtr = (void*)malloc(lengthSessId*sizeof(void*))))
    {
       LOGE("## getSessionIdentifierJni(): failure - identifier allocation OOM");
    }
    else
    {
        size_t result = olm_session_id(sessionPtr, sessionIdPtr, lengthSessId);
        if (result == olm_error())
        {
            const char *errorMsgPtr = olm_session_last_error(sessionPtr);
            LOGE("## getSessionIdentifierJni(): failure - get session identifier failure Msg=%s",errorMsgPtr);
        }
        else
        {
            returnValueStr = env->NewStringUTF((const char*)sessionIdPtr);
        }
        free(sessionIdPtr);
    }

    return returnValueStr;
}

/**
* Read the account instance ID of the calling object (aJavaObject) passed in parameter.
* @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=-1;
  jfieldID instanceIdField;
  jclass loaderClass;

  if(NULL!=aJniEnv)
  {
    if(0 != (loaderClass=aJniEnv->GetObjectClass(aJavaObject)))
    {
      if(0 != (instanceIdField=aJniEnv->GetFieldID(loaderClass, "mNativeOlmSessionId", "J")))
      {
        instanceId = aJniEnv->GetIntField(aJavaObject, instanceIdField);
        aJniEnv->DeleteLocalRef(loaderClass);
      }
      else
      {
        LOGD("## getSessionInstanceId() ERROR! GetFieldID=null");
      }
    }
    else
    {
      LOGD("## getSessionInstanceId() ERROR! GetObjectClass=null");
    }
  }
  else
  {
    LOGD("## getSessionInstanceId() ERROR! aJniEnv=NULL");
  }

  LOGD("## getSessionInstanceId() success - instanceId=%lld",instanceId);
  return instanceId;
}