1 | /* Copyright 2016 OpenMarket Ltd |
2 | * |
3 | * Licensed under the Apache License, Version 2.0 (the "License"); |
4 | * you may not use this file except in compliance with the License. |
5 | * You may obtain a copy of the License at |
6 | * |
7 | * http://www.apache.org/licenses/LICENSE-2.0 |
8 | * |
9 | * Unless required by applicable law or agreed to in writing, software |
10 | * distributed under the License is distributed on an "AS IS" BASIS, |
11 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | * See the License for the specific language governing permissions and |
13 | * limitations under the License. |
14 | */ |
15 | #ifndef OLM_OUTBOUND_GROUP_SESSION_H_ |
16 | #define OLM_OUTBOUND_GROUP_SESSION_H_ |
17 | |
18 | #include <stddef.h> |
19 | #include <stdint.h> |
20 | |
21 | #include "olm/error.h" |
22 | |
23 | #include "olm/olm_export.h" |
24 | |
25 | #ifdef __cplusplus |
26 | extern "C" { |
27 | #endif |
28 | |
29 | typedef struct OlmOutboundGroupSession OlmOutboundGroupSession; |
30 | |
31 | /** get the size of an outbound group session, in bytes. */ |
32 | OLM_EXPORT size_t olm_outbound_group_session_size(void); |
33 | |
34 | /** |
35 | * Initialise an outbound group session object using the supplied memory |
36 | * The supplied memory should be at least olm_outbound_group_session_size() |
37 | * bytes. |
38 | */ |
39 | OLM_EXPORT OlmOutboundGroupSession * olm_outbound_group_session( |
40 | void *memory |
41 | ); |
42 | |
43 | /** |
44 | * A null terminated string describing the most recent error to happen to a |
45 | * group session */ |
46 | OLM_EXPORT const char *olm_outbound_group_session_last_error( |
47 | const OlmOutboundGroupSession *session |
48 | ); |
49 | |
50 | /** |
51 | * An error code describing the most recent error to happen to a group |
52 | * session */ |
53 | OLM_EXPORT enum OlmErrorCode olm_outbound_group_session_last_error_code( |
54 | const OlmOutboundGroupSession *session |
55 | ); |
56 | |
57 | /** Clears the memory used to back this group session */ |
58 | OLM_EXPORT size_t olm_clear_outbound_group_session( |
59 | OlmOutboundGroupSession *session |
60 | ); |
61 | |
62 | /** Returns the number of bytes needed to store an outbound group session */ |
63 | OLM_EXPORT size_t olm_pickle_outbound_group_session_length( |
64 | const OlmOutboundGroupSession *session |
65 | ); |
66 | |
67 | /** |
68 | * Stores a group session as a base64 string. Encrypts the session using the |
69 | * supplied key. Returns the length of the session on success. |
70 | * |
71 | * Returns olm_error() on failure. If the pickle output buffer |
72 | * is smaller than olm_pickle_outbound_group_session_length() then |
73 | * olm_outbound_group_session_last_error() will be "OUTPUT_BUFFER_TOO_SMALL" |
74 | */ |
75 | OLM_EXPORT size_t olm_pickle_outbound_group_session( |
76 | OlmOutboundGroupSession *session, |
77 | void const * key, size_t key_length, |
78 | void * pickled, size_t pickled_length |
79 | ); |
80 | |
81 | /** |
82 | * Loads a group session from a pickled base64 string. Decrypts the session |
83 | * using the supplied key. |
84 | * |
85 | * Returns olm_error() on failure. If the key doesn't match the one used to |
86 | * encrypt the account then olm_outbound_group_session_last_error() will be |
87 | * "BAD_ACCOUNT_KEY". If the base64 couldn't be decoded then |
88 | * olm_outbound_group_session_last_error() will be "INVALID_BASE64". The input |
89 | * pickled buffer is destroyed |
90 | */ |
91 | OLM_EXPORT size_t olm_unpickle_outbound_group_session( |
92 | OlmOutboundGroupSession *session, |
93 | void const * key, size_t key_length, |
94 | void * pickled, size_t pickled_length |
95 | ); |
96 | |
97 | |
98 | /** The number of random bytes needed to create an outbound group session */ |
99 | OLM_EXPORT size_t olm_init_outbound_group_session_random_length( |
100 | const OlmOutboundGroupSession *session |
101 | ); |
102 | |
103 | /** |
104 | * Start a new outbound group session. Returns olm_error() on failure. On |
105 | * failure last_error will be set with an error code. The last_error will be |
106 | * NOT_ENOUGH_RANDOM if the number of random bytes was too small. |
107 | */ |
108 | OLM_EXPORT size_t olm_init_outbound_group_session( |
109 | OlmOutboundGroupSession *session, |
110 | uint8_t *random, size_t random_length |
111 | ); |
112 | |
113 | /** |
114 | * The number of bytes that will be created by encrypting a message |
115 | */ |
116 | OLM_EXPORT size_t olm_group_encrypt_message_length( |
117 | OlmOutboundGroupSession *session, |
118 | size_t plaintext_length |
119 | ); |
120 | |
121 | /** |
122 | * Encrypt some plain-text. Returns the length of the encrypted message or |
123 | * olm_error() on failure. On failure last_error will be set with an |
124 | * error code. The last_error will be OUTPUT_BUFFER_TOO_SMALL if the output |
125 | * buffer is too small. |
126 | */ |
127 | OLM_EXPORT size_t olm_group_encrypt( |
128 | OlmOutboundGroupSession *session, |
129 | uint8_t const * plaintext, size_t plaintext_length, |
130 | uint8_t * message, size_t message_length |
131 | ); |
132 | |
133 | |
134 | /** |
135 | * Get the number of bytes returned by olm_outbound_group_session_id() |
136 | */ |
137 | OLM_EXPORT size_t olm_outbound_group_session_id_length( |
138 | const OlmOutboundGroupSession *session |
139 | ); |
140 | |
141 | /** |
142 | * Get a base64-encoded identifier for this session. |
143 | * |
144 | * Returns the length of the session id on success or olm_error() on |
145 | * failure. On failure last_error will be set with an error code. The |
146 | * last_error will be OUTPUT_BUFFER_TOO_SMALL if the id buffer was too |
147 | * small. |
148 | */ |
149 | OLM_EXPORT size_t olm_outbound_group_session_id( |
150 | OlmOutboundGroupSession *session, |
151 | uint8_t * id, size_t id_length |
152 | ); |
153 | |
154 | /** |
155 | * Get the current message index for this session. |
156 | * |
157 | * Each message is sent with an increasing index; this returns the index for |
158 | * the next message. |
159 | */ |
160 | OLM_EXPORT uint32_t olm_outbound_group_session_message_index( |
161 | OlmOutboundGroupSession *session |
162 | ); |
163 | |
164 | /** |
165 | * Get the number of bytes returned by olm_outbound_group_session_key() |
166 | */ |
167 | OLM_EXPORT size_t olm_outbound_group_session_key_length( |
168 | const OlmOutboundGroupSession *session |
169 | ); |
170 | |
171 | /** |
172 | * Get the base64-encoded current ratchet key for this session. |
173 | * |
174 | * Each message is sent with a different ratchet key. This function returns the |
175 | * ratchet key that will be used for the next message. |
176 | * |
177 | * Returns the length of the ratchet key on success or olm_error() on |
178 | * failure. On failure last_error will be set with an error code. The |
179 | * last_error will be OUTPUT_BUFFER_TOO_SMALL if the buffer was too small. |
180 | */ |
181 | OLM_EXPORT size_t olm_outbound_group_session_key( |
182 | OlmOutboundGroupSession *session, |
183 | uint8_t * key, size_t key_length |
184 | ); |
185 | |
186 | |
187 | |
188 | #ifdef __cplusplus |
189 | } // extern "C" |
190 | #endif |
191 | |
192 | #endif /* OLM_OUTBOUND_GROUP_SESSION_H_ */ |
193 | |