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
|
/* 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.
*/
#ifndef OLM_INBOUND_GROUP_SESSION_H_
#define OLM_INBOUND_GROUP_SESSION_H_
#include <stddef.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef struct OlmInboundGroupSession OlmInboundGroupSession;
/** get the size of an inbound group session, in bytes. */
size_t olm_inbound_group_session_size();
/**
* Initialise an inbound group session object using the supplied memory
* The supplied memory should be at least olm_inbound_group_session_size()
* bytes.
*/
OlmInboundGroupSession * olm_inbound_group_session(
void *memory
);
/**
* A null terminated string describing the most recent error to happen to a
* group session */
const char *olm_inbound_group_session_last_error(
const OlmInboundGroupSession *session
);
/** Clears the memory used to back this group session */
size_t olm_clear_inbound_group_session(
OlmInboundGroupSession *session
);
/** Returns the number of bytes needed to store an inbound group session */
size_t olm_pickle_inbound_group_session_length(
const OlmInboundGroupSession *session
);
/**
* Stores a group session as a base64 string. Encrypts the session using the
* supplied key. Returns the length of the session on success.
*
* Returns olm_error() on failure. If the pickle output buffer
* is smaller than olm_pickle_inbound_group_session_length() then
* olm_inbound_group_session_last_error() will be "OUTPUT_BUFFER_TOO_SMALL"
*/
size_t olm_pickle_inbound_group_session(
OlmInboundGroupSession *session,
void const * key, size_t key_length,
void * pickled, size_t pickled_length
);
/**
* Loads a group session from a pickled base64 string. Decrypts the session
* using the supplied key.
*
* Returns olm_error() on failure. If the key doesn't match the one used to
* encrypt the account then olm_inbound_group_session_last_error() will be
* "BAD_ACCOUNT_KEY". If the base64 couldn't be decoded then
* olm_inbound_group_session_last_error() will be "INVALID_BASE64". The input
* pickled buffer is destroyed
*/
size_t olm_unpickle_inbound_group_session(
OlmInboundGroupSession *session,
void const * key, size_t key_length,
void * pickled, size_t pickled_length
);
/**
* Start a new inbound group session, from a key exported from
* olm_outbound_group_session_key
*
* Returns olm_error() on failure. On failure last_error will be set with an
* error code. The last_error will be:
*
* * OLM_INVALID_BASE64 if the session_key is not valid base64
* * OLM_BAD_SESSION_KEY if the session_key is invalid
*/
size_t olm_init_inbound_group_session(
OlmInboundGroupSession *session,
/* base64-encoded keys */
uint8_t const * session_key, size_t session_key_length
);
/**
* Import an inbound group session, from a previous export.
*
* Returns olm_error() on failure. On failure last_error will be set with an
* error code. The last_error will be:
*
* * OLM_INVALID_BASE64 if the session_key is not valid base64
* * OLM_BAD_SESSION_KEY if the session_key is invalid
*/
size_t olm_import_inbound_group_session(
OlmInboundGroupSession *session,
/* base64-encoded keys; note that it will be overwritten with the base64-decoded
data. */
uint8_t const * session_key, size_t session_key_length
);
/**
* Get an upper bound on the number of bytes of plain-text the decrypt method
* will write for a given input message length. The actual size could be
* different due to padding.
*
* The input message buffer is destroyed.
*
* Returns olm_error() on failure.
*/
size_t olm_group_decrypt_max_plaintext_length(
OlmInboundGroupSession *session,
uint8_t * message, size_t message_length
);
/**
* Decrypt a message.
*
* The input message buffer is destroyed.
*
* Returns the length of the decrypted plain-text, or olm_error() on failure.
*
* On failure last_error will be set with an error code. The last_error will
* be:
* * OLM_OUTPUT_BUFFER_TOO_SMALL if the plain-text buffer is too small
* * OLM_INVALID_BASE64 if the message is not valid base-64
* * OLM_BAD_MESSAGE_VERSION if the message was encrypted with an unsupported
* version of the protocol
* * OLM_BAD_MESSAGE_FORMAT if the message headers could not be decoded
* * OLM_BAD_MESSAGE_MAC if the message could not be verified
* * OLM_UNKNOWN_MESSAGE_INDEX if we do not have a session key corresponding to the
* message's index (ie, it was sent before the session key was shared with
* us)
*/
size_t olm_group_decrypt(
OlmInboundGroupSession *session,
/* input; note that it will be overwritten with the base64-decoded
message. */
uint8_t * message, size_t message_length,
/* output */
uint8_t * plaintext, size_t max_plaintext_length,
uint32_t * message_index
);
/**
* Get the number of bytes returned by olm_inbound_group_session_id()
*/
size_t olm_inbound_group_session_id_length(
const OlmInboundGroupSession *session
);
/**
* Get a base64-encoded identifier for this session.
*
* Returns the length of the session id on success or olm_error() on
* failure. On failure last_error will be set with an error code. The
* last_error will be OUTPUT_BUFFER_TOO_SMALL if the id buffer was too
* small.
*/
size_t olm_inbound_group_session_id(
OlmInboundGroupSession *session,
uint8_t * id, size_t id_length
);
/**
* Get the first message index we know how to decrypt.
*/
uint32_t olm_inbound_group_session_first_known_index(
const OlmInboundGroupSession *session
);
/**
* Get the number of bytes returned by olm_export_inbound_group_session()
*/
size_t olm_export_inbound_group_session_length(
const OlmInboundGroupSession *session
);
/**
* Export the base64-encoded ratchet key for this session, at the given index,
* in a format which can be used by olm_import_inbound_group_session
*
* Returns the length of the ratchet key on success or olm_error() on
* failure. On failure last_error will be set with an error code. The
* last_error will be:
* * OUTPUT_BUFFER_TOO_SMALL if the buffer was too small
* * OLM_UNKNOWN_MESSAGE_INDEX if we do not have a session key corresponding to the
* given index (ie, it was sent before the session key was shared with
* us)
*/
size_t olm_export_inbound_group_session(
OlmInboundGroupSession *session,
uint8_t * key, size_t key_length, uint32_t message_index
);
#ifdef __cplusplus
} // extern "C"
#endif
#endif /* OLM_INBOUND_GROUP_SESSION_H_ */
|
