OLMOutboundGroupSession.m 7.69 KB
Newer Older
1
2
/*
 Copyright 2016 OpenMarket Ltd
manuroe's avatar
manuroe committed
3
 Copyright 2016 Vector Creations Ltd
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

 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.
 */

#import "OLMOutboundGroupSession.h"

#import "OLMUtility.h"
#include "olm/olm.h"

@interface OLMOutboundGroupSession ()
{
    OlmOutboundGroupSession *session;
}
@end

@implementation OLMOutboundGroupSession

- (void)dealloc {
    olm_clear_outbound_group_session(session);
    free(session);
}

- (instancetype)init {
    self = [super init];
    if (self)
    {
        session = malloc(olm_outbound_group_session_size());
        if (session) {
            session = olm_outbound_group_session(session);
        }

        if (!session) {
            return nil;
        }
    }
    return self;
}

- (instancetype)initOutboundGroupSession {
    self = [self init];
    if (self) {
        NSMutableData *random = [OLMUtility randomBytesOfLength:olm_init_outbound_group_session_random_length(session)];

        size_t result = olm_init_outbound_group_session(session, random.mutableBytes, random.length);
        if (result == olm_error())   {
            const char *error = olm_outbound_group_session_last_error(session);
60
            NSLog(@"olm_init_outbound_group_session error: %s", error);
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
            return nil;
        }
    }
    return self;
}

- (NSString *)sessionIdentifier {
    size_t length = olm_outbound_group_session_id_length(session);
    NSMutableData *idData = [NSMutableData dataWithLength:length];
    if (!idData) {
        return nil;
    }
    size_t result = olm_outbound_group_session_id(session, idData.mutableBytes, idData.length);
    if (result == olm_error()) {
        const char *error = olm_outbound_group_session_last_error(session);
76
        NSLog(@"olm_outbound_group_session_id error: %s", error);
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
        return nil;
    }
    NSString *idString = [[NSString alloc] initWithData:idData encoding:NSUTF8StringEncoding];
    return idString;
}

- (NSUInteger)messageIndex {
    return olm_outbound_group_session_message_index(session);
}

- (NSString *)sessionKey {
    size_t length = olm_outbound_group_session_key_length(session);
    NSMutableData *sessionKeyData = [NSMutableData dataWithLength:length];
    if (!sessionKeyData) {
        return nil;
    }
    size_t result = olm_outbound_group_session_key(session, sessionKeyData.mutableBytes, sessionKeyData.length);
    if (result == olm_error()) {
        const char *error = olm_outbound_group_session_last_error(session);
96
        NSLog(@"olm_outbound_group_session_key error: %s", error);
97
98
99
100
101
102
        return nil;
    }
    NSString *sessionKey = [[NSString alloc] initWithData:sessionKeyData encoding:NSUTF8StringEncoding];
    return sessionKey;
}

103
- (NSString *)encryptMessage:(NSString *)message error:(NSError**)error {
104
105
106
107
108
109
110
111
    NSData *plaintextData = [message dataUsingEncoding:NSUTF8StringEncoding];
    size_t ciphertextLength = olm_group_encrypt_message_length(session, plaintextData.length);
    NSMutableData *ciphertext = [NSMutableData dataWithLength:ciphertextLength];
    if (!ciphertext) {
        return nil;
    }
    size_t result = olm_group_encrypt(session, plaintextData.bytes, plaintextData.length, ciphertext.mutableBytes, ciphertext.length);
    if (result == olm_error()) {
112
113
114
115
116
117
118
119
120
        const char *olm_error = olm_outbound_group_session_last_error(session);

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

        if (error && olm_error && errorString) {
            *error = [NSError errorWithDomain:OLMErrorDomain
                                         code:0
                                     userInfo:@{
121
122
                                                NSLocalizedDescriptionKey: errorString,
                                                NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:@"olm_group_encrypt error: %@", errorString]
123
124
125
                                                }];
        }

126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
        return nil;
    }
    return [[NSString alloc] initWithData:ciphertext encoding:NSUTF8StringEncoding];
}

#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 *__autoreleasing *)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) {
143
            *error = [NSError errorWithDomain:OLMErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey: @"Bad length."}];
144
145
146
147
148
149
150
151
152
        }
        return nil;
    }
    NSMutableData *pickle = [serializedData dataUsingEncoding:NSUTF8StringEncoding].mutableCopy;
    size_t result = olm_unpickle_outbound_group_session(session, key.bytes, key.length, pickle.mutableBytes, pickle.length);
    if (result == olm_error()) {
        const char *olm_error = olm_outbound_group_session_last_error(session);
        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        if (error && errorString) {
153
            *error = [NSError errorWithDomain:OLMErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey: errorString}];
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
        }
        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_outbound_group_session_length(session);
    NSMutableData *pickled = [NSMutableData dataWithLength:length];
    size_t result = olm_pickle_outbound_group_session(session, key.bytes, key.length, pickled.mutableBytes, pickled.length);
    if (result == olm_error()) {
        const char *olm_error = olm_outbound_group_session_last_error(session);
        NSString *errorString = [NSString stringWithUTF8String:olm_error];
        if (error && errorString) {
170
            *error = [NSError errorWithDomain:OLMErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey: errorString}];
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
        }
        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"];
}

@end