OLMSession.m 14.5 KB
Newer Older
manuroe's avatar
manuroe committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
/*
 Copyright 2016 Chris Ballinger
 Copyright 2016 OpenMarket Ltd
 Copyright 2016 Vector Creations 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.
 */
Chris Ballinger's avatar
Chris Ballinger committed
18
19

#import "OLMSession.h"
Chris Ballinger's avatar
Chris Ballinger committed
20
21
#import "OLMUtility.h"
#import "OLMAccount_Private.h"
22
#import "OLMSession_Private.h"
manuroe's avatar
manuroe committed
23
#include "olm/olm.h"
Chris Ballinger's avatar
Chris Ballinger committed
24
25
26

@implementation OLMSession

Chris Ballinger's avatar
Chris Ballinger committed
27
28
29
- (void) dealloc {
    olm_clear_session(_session);
    free(_session);
Chris Ballinger's avatar
Chris Ballinger committed
30
31
}

Chris Ballinger's avatar
Chris Ballinger committed
32
33
34
35
36
37
38
39
40
41
42
43
44
- (BOOL) initializeSessionMemory {
    size_t size = olm_session_size();
    _session = malloc(size);
    NSParameterAssert(_session != nil);
    if (!_session) {
        return NO;
    }
    _session = olm_session(_session);
    NSParameterAssert(_session != nil);
    if (!_session) {
        return NO;
    }
    return YES;
Chris Ballinger's avatar
Chris Ballinger committed
45
46
}

47
- (instancetype) init {
Chris Ballinger's avatar
Chris Ballinger committed
48
49
50
51
52
53
54
55
    self = [super init];
    if (!self) {
        return nil;
    }
    BOOL success = [self initializeSessionMemory];
    if (!success) {
        return nil;
    }
56
57
58
59
60
61
62
63
64
65
66
67
    return self;
}

- (instancetype) initWithAccount:(OLMAccount*)account {
    self = [self init];
    if (!self) {
        return nil;
    }
    NSParameterAssert(account != nil &&  account.account != NULL);
    if (account == nil || account.account == NULL) {
        return nil;
    }
Chris Ballinger's avatar
Chris Ballinger committed
68
69
70
71
    _account = account;
    return self;
}

72
- (instancetype) initOutboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey theirOneTimeKey:(NSString*)theirOneTimeKey  error:(NSError**)error {
Chris Ballinger's avatar
Chris Ballinger committed
73
74
75
76
77
78
79
80
81
    self = [self initWithAccount:account];
    if (!self) {
        return nil;
    }
    NSMutableData *random = [OLMUtility randomBytesOfLength:olm_create_outbound_session_random_length(_session)];
    NSData *idKey = [theirIdentityKey dataUsingEncoding:NSUTF8StringEncoding];
    NSData *otKey = [theirOneTimeKey dataUsingEncoding:NSUTF8StringEncoding];
    size_t result = olm_create_outbound_session(_session, account.account, idKey.bytes, idKey.length, otKey.bytes, otKey.length, random.mutableBytes, random.length);
    if (result == olm_error()) {
82
83
84
85
86
87
88
89
90
91
92
93
94
        const char *olm_error = olm_session_last_error(_session);

        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        NSLog(@"olm_create_outbound_session error: %@", errorString);

        if (error && olm_error && errorString) {
            *error = [NSError errorWithDomain:OLMErrorDomain
                                         code:0
                                     userInfo:@{
                                                NSLocalizedDescriptionKey: [NSString stringWithFormat:@"olm_create_outbound_session error: %@", errorString]
                                                }];
        }

Chris Ballinger's avatar
Chris Ballinger committed
95
96
97
98
99
        return nil;
    }
    return self;
}

100
- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account oneTimeKeyMessage:(NSString*)oneTimeKeyMessage error:(NSError**)error {
Chris Ballinger's avatar
Chris Ballinger committed
101
102
103
104
105
106
107
    self = [self initWithAccount:account];
    if (!self) {
        return nil;
    }
    NSMutableData *otk = [NSMutableData dataWithData:[oneTimeKeyMessage dataUsingEncoding:NSUTF8StringEncoding]];
    size_t result = olm_create_inbound_session(_session, account.account, otk.mutableBytes, oneTimeKeyMessage.length);
    if (result == olm_error()) {
108
109
110
111
112
113
114
115
116
117
118
119
120
        const char *olm_error = olm_session_last_error(_session);

        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        NSLog(@"olm_create_inbound_session error: %@", errorString);

        if (error && olm_error && errorString) {
            *error = [NSError errorWithDomain:OLMErrorDomain
                                         code:0
                                     userInfo:@{
                                                NSLocalizedDescriptionKey: [NSString stringWithFormat:@"olm_create_inbound_session error: %@", errorString]
                                                }];
        }

Chris Ballinger's avatar
Chris Ballinger committed
121
122
123
124
125
        return nil;
    }
    return self;
}

126
- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey oneTimeKeyMessage:(NSString*)oneTimeKeyMessage error:(NSError**)error {
Chris Ballinger's avatar
Chris Ballinger committed
127
128
129
130
131
132
133
134
    self = [self initWithAccount:account];
    if (!self) {
        return nil;
    }
    NSData *idKey = [theirIdentityKey dataUsingEncoding:NSUTF8StringEncoding];
    NSMutableData *otk = [NSMutableData dataWithData:[oneTimeKeyMessage dataUsingEncoding:NSUTF8StringEncoding]];
    size_t result = olm_create_inbound_session_from(_session, account.account, idKey.bytes, idKey.length, otk.mutableBytes, otk.length);
    if (result == olm_error()) {
135
136
137
138
139
140
141
142
143
144
145
146
147
        const char *olm_error = olm_session_last_error(_session);

        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        NSLog(@"olm_create_inbound_session_from error: %@", errorString);

        if (error && olm_error && errorString) {
            *error = [NSError errorWithDomain:OLMErrorDomain
                                         code:0
                                     userInfo:@{
                                                NSLocalizedDescriptionKey: [NSString stringWithFormat:@"olm_create_inbound_session_from error: %@", errorString]
                                                }];
        }

Chris Ballinger's avatar
Chris Ballinger committed
148
149
150
151
152
153
154
155
156
157
158
159
160
161
        return nil;
    }
    return self;
}

- (NSString*) sessionIdentifier {
    size_t length = olm_session_id_length(_session);
    NSMutableData *idData = [NSMutableData dataWithLength:length];
    if (!idData) {
        return nil;
    }
    size_t result = olm_session_id(_session, idData.mutableBytes, idData.length);
    if (result == olm_error()) {
        const char *error = olm_session_last_error(_session);
162
        NSLog(@"olm_session_id error: %s", error);
Chris Ballinger's avatar
Chris Ballinger committed
163
164
165
166
167
168
        return nil;
    }
    NSString *idString = [[NSString alloc] initWithData:idData encoding:NSUTF8StringEncoding];
    return idString;
}

169
- (BOOL)matchesInboundSession:(NSString *)oneTimeKeyMessage {
170
    NSMutableData *otk = [NSMutableData dataWithData:[oneTimeKeyMessage dataUsingEncoding:NSUTF8StringEncoding]];
171

172
    size_t result = olm_matches_inbound_session(_session, otk.mutableBytes, otk.length);
173
174
175
176
177
178
179
180
181
182
183
184
185
186
    if (result == 1) {
        return YES;
    }
    else {
        if (result == olm_error()) {
            const char *error = olm_session_last_error(_session);
            NSLog(@"olm_matches_inbound_session error: %s", error);
        }
        return NO;
    }
}

- (BOOL)matchesInboundSessionFrom:(NSString *)theirIdentityKey oneTimeKeyMessage:(NSString *)oneTimeKeyMessage {
    NSData *idKey = [theirIdentityKey dataUsingEncoding:NSUTF8StringEncoding];
187
    NSMutableData *otk = [NSMutableData dataWithData:[oneTimeKeyMessage dataUsingEncoding:NSUTF8StringEncoding]];
188
189
190

    size_t result = olm_matches_inbound_session_from(_session,
                                                     idKey.bytes, idKey.length,
191
                                                     otk.mutableBytes, otk.length);
192
193
194
195
196
197
198
199
200
201
202
203
    if (result == 1) {
        return YES;
    }
    else {
        if (result == olm_error()) {
            const char *error = olm_session_last_error(_session);
            NSLog(@"olm_matches_inbound_session error: %s", error);
        }
        return NO;
    }
}

204
- (OLMMessage*) encryptMessage:(NSString*)message error:(NSError**)error {
Chris Ballinger's avatar
Chris Ballinger committed
205
206
207
208
209
210
211
212
213
214
215
    size_t messageType = olm_encrypt_message_type(_session);
    size_t randomLength = olm_encrypt_random_length(_session);
    NSMutableData *random = [OLMUtility randomBytesOfLength:randomLength];
    NSData *plaintextData = [message dataUsingEncoding:NSUTF8StringEncoding];
    size_t ciphertextLength = olm_encrypt_message_length(_session, plaintextData.length);
    NSMutableData *ciphertext = [NSMutableData dataWithLength:ciphertextLength];
    if (!ciphertext) {
        return nil;
    }
    size_t result = olm_encrypt(_session, plaintextData.bytes, plaintextData.length, random.mutableBytes, random.length, ciphertext.mutableBytes, ciphertext.length);
    if (result == olm_error()) {
216
217
218
219
220
221
222
223
224
225
226
227
228
        const char *olm_error = olm_session_last_error(_session);

        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        NSLog(@"olm_encrypt error: %@", errorString);

        if (error && olm_error && errorString) {
            *error = [NSError errorWithDomain:OLMErrorDomain
                                         code:0
                                     userInfo:@{
                                                NSLocalizedDescriptionKey: [NSString stringWithFormat:@"olm_encrypt error: %@", errorString]
                                                }];
        }

Chris Ballinger's avatar
Chris Ballinger committed
229
230
231
232
233
234
235
        return nil;
    }
    NSString *ciphertextString = [[NSString alloc] initWithData:ciphertext encoding:NSUTF8StringEncoding];
    OLMMessage *encryptedMessage = [[OLMMessage alloc] initWithCiphertext:ciphertextString type:messageType];
    return encryptedMessage;
}

236
- (NSString*) decryptMessage:(OLMMessage*)message error:(NSError**)error {
Chris Ballinger's avatar
Chris Ballinger committed
237
238
239
240
241
242
243
244
    NSParameterAssert(message != nil);
    NSData *messageData = [message.ciphertext dataUsingEncoding:NSUTF8StringEncoding];
    if (!messageData) {
        return nil;
    }
    NSMutableData *mutMessage = messageData.mutableCopy;
    size_t maxPlaintextLength = olm_decrypt_max_plaintext_length(_session, message.type, mutMessage.mutableBytes, mutMessage.length);
    if (maxPlaintextLength == olm_error()) {
245
246
247
248
249
250
251
252
253
254
255
256
257
        const char *olm_error = olm_session_last_error(_session);

        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        NSLog(@"olm_decrypt_max_plaintext_length error: %@", errorString);

        if (error && olm_error && errorString) {
            *error = [NSError errorWithDomain:OLMErrorDomain
                                         code:0
                                     userInfo:@{
                                                NSLocalizedDescriptionKey: [NSString stringWithFormat:@"olm_decrypt_max_plaintext_length error: %@", errorString]
                                                }];
        }

Chris Ballinger's avatar
Chris Ballinger committed
258
259
260
261
262
263
264
        return nil;
    }
    // message buffer is destroyed by olm_decrypt_max_plaintext_length
    mutMessage = messageData.mutableCopy;
    NSMutableData *plaintextData = [NSMutableData dataWithLength:maxPlaintextLength];
    size_t plaintextLength = olm_decrypt(_session, message.type, mutMessage.mutableBytes, mutMessage.length, plaintextData.mutableBytes, plaintextData.length);
    if (plaintextLength == olm_error()) {
265
266
267
268
269
270
271
272
273
274
275
276
277
        const char *olm_error = olm_session_last_error(_session);

        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        NSLog(@"olm_decrypt error: %@", errorString);

        if (error && olm_error && errorString) {
            *error = [NSError errorWithDomain:OLMErrorDomain
                                         code:0
                                     userInfo:@{
                                                NSLocalizedDescriptionKey: [NSString stringWithFormat:@"olm_decrypt error: %@", errorString]
                                                }];
        }

Chris Ballinger's avatar
Chris Ballinger committed
278
279
280
281
282
        return nil;
    }
    plaintextData.length = plaintextLength;
    NSString *plaintext = [[NSString alloc] initWithData:plaintextData encoding:NSUTF8StringEncoding];
    return plaintext;
Chris Ballinger's avatar
Chris Ballinger committed
283
284
}

285
286
287
288
289
290
291
292
293
294
295
296
#pragma mark OLMSerializable

/** Initializes from encrypted serialized data. Will throw error if invalid key or invalid base64. */
- (instancetype) initWithSerializedData:(NSString*)serializedData key:(NSData*)key error:(NSError**)error {
    self = [self init];
    if (!self) {
        return nil;
    }
    NSParameterAssert(key.length > 0);
    NSParameterAssert(serializedData.length > 0);
    if (key.length == 0 || serializedData.length == 0) {
        if (error) {
297
            *error = [NSError errorWithDomain:OLMErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey: @"Bad length."}];
298
299
300
301
302
303
304
305
306
        }
        return nil;
    }
    NSMutableData *pickle = [serializedData dataUsingEncoding:NSUTF8StringEncoding].mutableCopy;
    size_t result = olm_unpickle_session(_session, key.bytes, key.length, pickle.mutableBytes, pickle.length);
    if (result == olm_error()) {
        const char *olm_error = olm_session_last_error(_session);
        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        if (error && errorString) {
307
            *error = [NSError errorWithDomain:OLMErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey: errorString}];
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
        }
        return nil;
    }
    return self;
}

/** Serializes and encrypts object data, outputs base64 blob */
- (NSString*) serializeDataWithKey:(NSData*)key error:(NSError**)error {
    NSParameterAssert(key.length > 0);
    size_t length = olm_pickle_session_length(_session);
    NSMutableData *pickled = [NSMutableData dataWithLength:length];
    size_t result = olm_pickle_session(_session, key.bytes, key.length, pickled.mutableBytes, pickled.length);
    if (result == olm_error()) {
        const char *olm_error = olm_session_last_error(_session);
        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        if (error && errorString) {
324
            *error = [NSError errorWithDomain:OLMErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey: errorString}];
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
        }
        return nil;
    }
    NSString *pickleString = [[NSString alloc] initWithData:pickled encoding:NSUTF8StringEncoding];
    return pickleString;
}

#pragma mark NSSecureCoding

+ (BOOL) supportsSecureCoding {
    return YES;
}

#pragma mark NSCoding

- (id)initWithCoder:(NSCoder *)decoder {
    NSString *version = [decoder decodeObjectOfClass:[NSString class] forKey:@"version"];
    
    NSError *error = nil;
    
    if ([version isEqualToString:@"1"]) {
        NSString *pickle = [decoder decodeObjectOfClass:[NSString class] forKey:@"pickle"];
        NSData *key = [decoder decodeObjectOfClass:[NSData class] forKey:@"key"];
        
        self = [self initWithSerializedData:pickle key:key error:&error];
    }
    
    NSParameterAssert(error == nil);
    NSParameterAssert(self != nil);
    if (!self) {
        return nil;
    }
    
    return self;
}

- (void)encodeWithCoder:(NSCoder *)encoder {
    NSData *key = [OLMUtility randomBytesOfLength:32];
    NSError *error = nil;
    NSString *pickle = [self serializeDataWithKey:key error:&error];
    NSParameterAssert(pickle.length > 0 && error == nil);
    
    [encoder encodeObject:pickle forKey:@"pickle"];
    [encoder encodeObject:key forKey:@"key"];
    [encoder encodeObject:@"1" forKey:@"version"];
}

Chris Ballinger's avatar
Chris Ballinger committed
372
@end