libSRTP
srtp.h
1/*
2 * srtp.h
3 *
4 * interface to libsrtp
5 *
6 * David A. McGrew
7 * Cisco Systems, Inc.
8 */
9/*
10 *
11 * Copyright (c) 2001-2017, Cisco Systems, Inc.
12 * All rights reserved.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 *
18 * Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 *
21 * Redistributions in binary form must reproduce the above
22 * copyright notice, this list of conditions and the following
23 * disclaimer in the documentation and/or other materials provided
24 * with the distribution.
25 *
26 * Neither the name of the Cisco Systems, Inc. nor the names of its
27 * contributors may be used to endorse or promote products derived
28 * from this software without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
33 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
34 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
35 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
36 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
37 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
41 * OF THE POSSIBILITY OF SUCH DAMAGE.
42 *
43 */
44
45#ifndef SRTP_SRTP_H
46#define SRTP_SRTP_H
47
48#include <stdint.h>
49
50#ifdef __cplusplus
51extern "C" {
52#endif
53
63/*
64 * SRTP_MASTER_KEY_LEN is the nominal master key length supported by libSRTP
65 */
66
67#define SRTP_MASTER_KEY_LEN 30
68
69/*
70 * SRTP_MAX_KEY_LEN is the maximum key length supported by libSRTP
71 */
72#define SRTP_MAX_KEY_LEN 64
73
74/*
75 * SRTP_MAX_TAG_LEN is the maximum tag length supported by libSRTP
76 */
77
78#define SRTP_MAX_TAG_LEN 16
79
84#define SRTP_MAX_MKI_LEN 128
85
94#define SRTP_MAX_TRAILER_LEN (SRTP_MAX_TAG_LEN + SRTP_MAX_MKI_LEN)
95
101#define SRTP_MAX_NUM_MASTER_KEYS 16
102
103#define SRTP_SALT_LEN 14
104
105/*
106 * SRTP_AEAD_SALT_LEN is the length of the SALT values used with
107 * GCM mode. GCM mode requires an IV. The SALT value is used
108 * as part of the IV formation logic applied to each RTP packet.
109 */
110#define SRTP_AEAD_SALT_LEN 12
111
112#define SRTP_AES_128_KEY_LEN 16
113#define SRTP_AES_192_KEY_LEN 24
114#define SRTP_AES_256_KEY_LEN 32
115
116#define SRTP_AES_ICM_128_KEY_LEN_WSALT (SRTP_SALT_LEN + SRTP_AES_128_KEY_LEN)
117#define SRTP_AES_ICM_192_KEY_LEN_WSALT (SRTP_SALT_LEN + SRTP_AES_192_KEY_LEN)
118#define SRTP_AES_ICM_256_KEY_LEN_WSALT (SRTP_SALT_LEN + SRTP_AES_256_KEY_LEN)
119
120#define SRTP_AES_GCM_128_KEY_LEN_WSALT \
121 (SRTP_AEAD_SALT_LEN + SRTP_AES_128_KEY_LEN)
122#define SRTP_AES_GCM_192_KEY_LEN_WSALT \
123 (SRTP_AEAD_SALT_LEN + SRTP_AES_192_KEY_LEN)
124#define SRTP_AES_GCM_256_KEY_LEN_WSALT \
125 (SRTP_AEAD_SALT_LEN + SRTP_AES_256_KEY_LEN)
126
139typedef uint32_t srtp_cipher_type_id_t;
140
154typedef uint32_t srtp_auth_type_id_t;
155
164typedef enum {
200
201typedef struct srtp_ctx_t_ srtp_ctx_t;
202
210typedef enum {
216
226typedef struct srtp_crypto_policy_t {
240
247typedef enum {
250 ssrc_any_inbound = 2,
257
267typedef struct {
269 unsigned int value;
272
279typedef struct srtp_master_key_t {
280 unsigned char *key;
281 unsigned char *mki_id;
282 unsigned int mki_size;
284
311typedef struct srtp_policy_t {
318 unsigned char *key;
320 srtp_master_key_t **keys;
321 unsigned long num_master_keys;
324 unsigned long window_size;
338
351typedef srtp_ctx_t *srtp_t;
352
360
367
408srtp_err_status_t srtp_protect(srtp_t ctx, void *rtp_hdr, int *len_ptr);
409
459 void *rtp_hdr,
460 int *pkt_octet_len,
461 unsigned int use_mki,
462 unsigned int mki_index);
463
504srtp_err_status_t srtp_unprotect(srtp_t ctx, void *srtp_hdr, int *len_ptr);
505
553 void *srtp_hdr,
554 int *len_ptr,
555 unsigned int use_mki);
556
579
595
618
644
667 const srtp_policy_t *policy);
668
688
708
723#define srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(p) \
724 srtp_crypto_policy_set_rtp_default(p)
725
757
784
810
835
859
891
918
942
974
1001
1024
1047
1070
1093
1116
1139
1156
1157/*
1158 * @brief identifies a particular SRTP profile
1159 *
1160 * An srtp_profile_t enumeration is used to identify a particular SRTP
1161 * profile (that is, a set of algorithms and parameters).
1162 */
1163typedef enum {
1164 srtp_profile_reserved = 0,
1165 srtp_profile_aes128_cm_sha1_80 = 1,
1166 srtp_profile_aes128_cm_sha1_32 = 2,
1167 srtp_profile_null_sha1_80 = 5,
1168 srtp_profile_null_sha1_32 = 6,
1169 srtp_profile_aead_aes_128_gcm = 7,
1170 srtp_profile_aead_aes_256_gcm = 8,
1171} srtp_profile_t;
1172
1197 srtp_crypto_policy_t *policy,
1198 srtp_profile_t profile);
1199
1224 srtp_crypto_policy_t *policy,
1225 srtp_profile_t profile);
1226
1230unsigned int srtp_profile_get_master_key_length(srtp_profile_t profile);
1231
1235unsigned int srtp_profile_get_master_salt_length(srtp_profile_t profile);
1236
1248void srtp_append_salt_to_key(unsigned char *key,
1249 unsigned int bytes_in_key,
1250 unsigned char *salt,
1251 unsigned int bytes_in_salt);
1252
1314 void *rtcp_hdr,
1315 int *pkt_octet_len);
1316
1363 void *rtcp_hdr,
1364 int *pkt_octet_len,
1365 unsigned int use_mki,
1366 unsigned int mki_index);
1367
1407 void *srtcp_hdr,
1408 int *pkt_octet_len);
1409
1456 void *srtcp_hdr,
1457 int *pkt_octet_len,
1458 unsigned int use_mki);
1459
1486void srtp_set_user_data(srtp_t ctx, void *data);
1487
1504
1550typedef enum {
1559
1567typedef struct srtp_event_data_t {
1569 uint32_t ssrc;
1573
1585
1599
1604const char *srtp_get_version_string(void);
1605
1610unsigned int srtp_get_version(void);
1611
1620srtp_err_status_t srtp_set_debug_module(const char *mod_name, int v);
1621
1627
1635typedef enum {
1641
1653 const char *msg,
1654 void *data);
1655
1671 void *data);
1672
1685 uint32_t use_mki,
1686 uint32_t mki_index,
1687 uint32_t *length);
1688
1702 uint32_t use_mki,
1703 uint32_t mki_index,
1704 uint32_t *length);
1705
1716 uint32_t ssrc,
1717 uint32_t roc);
1718
1729 uint32_t ssrc,
1730 uint32_t *roc);
1731
1736/* in host order, so outside the #if */
1737#define SRTCP_E_BIT 0x80000000
1738
1739/* for byte-access */
1740#define SRTCP_E_BYTE_BIT 0x80
1741#define SRTCP_INDEX_MASK 0x7fffffff
1742
1743#ifdef __cplusplus
1744}
1745#endif
1746
1747#endif /* SRTP_SRTP_H */
srtp_err_status_t srtp_protect_rtcp_mki(srtp_t ctx, void *rtcp_hdr, int *pkt_octet_len, unsigned int use_mki, unsigned int mki_index)
srtp_protect_rtcp_mki() is the Secure RTCP sender-side packet processing function that can utilize mk...
srtp_err_status_t srtp_unprotect_rtcp(srtp_t ctx, void *srtcp_hdr, int *pkt_octet_len)
srtp_unprotect_rtcp() is the Secure RTCP receiver-side packet processing function.
srtp_err_status_t srtp_protect_rtcp(srtp_t ctx, void *rtcp_hdr, int *pkt_octet_len)
srtp_protect_rtcp() is the Secure RTCP sender-side packet processing function.
srtp_err_status_t srtp_unprotect_rtcp_mki(srtp_t ctx, void *srtcp_hdr, int *pkt_octet_len, unsigned int use_mki)
srtp_unprotect_rtcp() is the Secure RTCP receiver-side packet processing function.
void srtp_append_salt_to_key(unsigned char *key, unsigned int bytes_in_key, unsigned char *salt, unsigned int bytes_in_salt)
appends the salt to the key
srtp_err_status_t srtp_update_stream(srtp_t session, const srtp_policy_t *policy)
srtp_update_stream() updates a SRTP stream.
srtp_ctx_t * srtp_t
An srtp_t points to an SRTP session structure.
Definition srtp.h:351
void srtp_crypto_policy_set_rtcp_default(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_rtcp_default() sets a crypto policy structure to the SRTP default policy for R...
srtp_err_status_t srtp_crypto_policy_set_from_profile_for_rtp(srtp_crypto_policy_t *policy, srtp_profile_t profile)
srtp_crypto_policy_set_from_profile_for_rtp() sets a crypto policy structure to the appropriate value...
srtp_err_status_t
srtp_err_status_t defines error codes.
Definition srtp.h:164
void srtp_crypto_policy_set_aes_cm_192_hmac_sha1_32(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_cm_192_hmac_sha1_32() sets a crypto policy structure to a short-authentica...
unsigned int srtp_profile_get_master_salt_length(srtp_profile_t profile)
returns the master salt length for a given SRTP profile
void srtp_crypto_policy_set_aes_gcm_256_16_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_gcm_256_16_auth() sets a crypto policy structure to an AEAD encryption pol...
void srtp_crypto_policy_set_aes_cm_256_null_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_cm_256_null_auth() sets a crypto policy structure to an encryption-only po...
void srtp_crypto_policy_set_aes_gcm_128_8_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_gcm_128_8_auth() sets a crypto policy structure to an AEAD encryption poli...
void srtp_crypto_policy_set_rtp_default(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_rtp_default() sets a crypto policy structure to the SRTP default policy for RT...
srtp_ssrc_type_t
srtp_ssrc_type_t describes the type of an SSRC.
Definition srtp.h:247
void srtp_crypto_policy_set_aes_gcm_256_8_only_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_gcm_256_8_only_auth() sets a crypto policy structure to an AEAD authentica...
void srtp_crypto_policy_set_aes_cm_256_hmac_sha1_32(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_cm_256_hmac_sha1_32() sets a crypto policy structure to a short-authentica...
void srtp_crypto_policy_set_aes_cm_128_hmac_sha1_32(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_cm_128_hmac_sha1_32() sets a crypto policy structure to a short-authentica...
void srtp_crypto_policy_set_aes_cm_192_hmac_sha1_80(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_cm_192_hmac_sha1_80() sets a crypto policy structure to a encryption and a...
void srtp_crypto_policy_set_null_cipher_hmac_sha1_80(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_null_cipher_hmac_sha1_80() sets a crypto policy structure to an authentication...
srtp_err_status_t srtp_crypto_policy_set_from_profile_for_rtcp(srtp_crypto_policy_t *policy, srtp_profile_t profile)
srtp_crypto_policy_set_from_profile_for_rtcp() sets a crypto policy structure to the appropriate valu...
srtp_err_status_t srtp_dealloc(srtp_t s)
srtp_dealloc() deallocates storage for an SRTP session context.
srtp_err_status_t srtp_add_stream(srtp_t session, const srtp_policy_t *policy)
srtp_add_stream() allocates and initializes an SRTP stream within a given SRTP session.
srtp_err_status_t srtp_update(srtp_t session, const srtp_policy_t *policy)
srtp_update() updates all streams in the session.
srtp_sec_serv_t
srtp_sec_serv_t describes a set of security services.
Definition srtp.h:210
srtp_err_status_t srtp_remove_stream(srtp_t session, unsigned int ssrc)
srtp_remove_stream() deallocates an SRTP stream.
srtp_err_status_t srtp_create(srtp_t *session, const srtp_policy_t *policy)
srtp_create() allocates and initializes an SRTP session.
void srtp_crypto_policy_set_aes_cm_256_hmac_sha1_80(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_cm_256_hmac_sha1_80() sets a crypto policy structure to a encryption and a...
srtp_err_status_t srtp_unprotect(srtp_t ctx, void *srtp_hdr, int *len_ptr)
srtp_unprotect() is the Secure RTP receiver-side packet processing function.
uint32_t srtp_cipher_type_id_t
A srtp_cipher_type_id_t is an identifier for a particular cipher type.
Definition srtp.h:139
srtp_err_status_t srtp_shutdown(void)
srtp_shutdown() de-initializes the srtp library.
void srtp_crypto_policy_set_aes_cm_128_null_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_cm_128_null_auth() sets a crypto policy structure to an encryption-only po...
srtp_err_status_t srtp_protect_mki(srtp_ctx_t *ctx, void *rtp_hdr, int *pkt_octet_len, unsigned int use_mki, unsigned int mki_index)
srtp_protect_mki() is the Secure RTP sender-side packet processing function that can utilize MKI.
void srtp_crypto_policy_set_aes_cm_192_null_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_cm_192_null_auth() sets a crypto policy structure to an encryption-only po...
void srtp_crypto_policy_set_aes_gcm_128_16_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_gcm_128_16_auth() sets a crypto policy structure to an AEAD encryption pol...
void srtp_crypto_policy_set_aes_gcm_256_8_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_gcm_256_8_auth() sets a crypto policy structure to an AEAD encryption poli...
uint32_t srtp_auth_type_id_t
An srtp_auth_type_id_t is an identifier for a particular authentication function.
Definition srtp.h:154
void srtp_crypto_policy_set_aes_gcm_128_8_only_auth(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_aes_gcm_128_8_only_auth() sets a crypto policy structure to an AEAD authentica...
srtp_err_status_t srtp_protect(srtp_t ctx, void *rtp_hdr, int *len_ptr)
srtp_protect() is the Secure RTP sender-side packet processing function.
unsigned int srtp_profile_get_master_key_length(srtp_profile_t profile)
returns the master key length for a given SRTP profile
void srtp_crypto_policy_set_null_cipher_hmac_null(srtp_crypto_policy_t *p)
srtp_crypto_policy_set_null_cipher_hmac_null() sets a crypto policy structure to use no encryption or...
srtp_err_status_t srtp_init(void)
srtp_init() initializes the srtp library.
srtp_err_status_t srtp_unprotect_mki(srtp_t ctx, void *srtp_hdr, int *len_ptr, unsigned int use_mki)
srtp_unprotect_mki() is the Secure RTP receiver-side packet processing function that checks for MKI.
@ srtp_err_status_write_fail
Definition srtp.h:188
@ srtp_err_status_parse_err
Definition srtp.h:189
@ srtp_err_status_socket_err
Definition srtp.h:184
@ srtp_err_status_read_fail
Definition srtp.h:187
@ srtp_err_status_bad_mki
Definition srtp.h:193
@ srtp_err_status_pkt_idx_adv
Definition srtp.h:197
@ srtp_err_status_auth_fail
Definition srtp.h:173
@ srtp_err_status_init_fail
Definition srtp.h:170
@ srtp_err_status_encode_err
Definition srtp.h:190
@ srtp_err_status_cant_check
Definition srtp.h:181
@ srtp_err_status_replay_fail
Definition srtp.h:175
@ srtp_err_status_ok
Definition srtp.h:165
@ srtp_err_status_pkt_idx_old
Definition srtp.h:195
@ srtp_err_status_bad_param
Definition srtp.h:167
@ srtp_err_status_signal_err
Definition srtp.h:185
@ srtp_err_status_cipher_fail
Definition srtp.h:174
@ srtp_err_status_terminus
Definition srtp.h:171
@ srtp_err_status_replay_old
Definition srtp.h:176
@ srtp_err_status_fail
Definition srtp.h:166
@ srtp_err_status_semaphore_err
Definition srtp.h:191
@ srtp_err_status_algo_fail
Definition srtp.h:178
@ srtp_err_status_nonce_bad
Definition srtp.h:186
@ srtp_err_status_no_such_op
Definition srtp.h:179
@ srtp_err_status_pfkey_err
Definition srtp.h:192
@ srtp_err_status_no_ctx
Definition srtp.h:180
@ srtp_err_status_dealloc_fail
Definition srtp.h:169
@ srtp_err_status_alloc_fail
Definition srtp.h:168
@ srtp_err_status_key_expired
Definition srtp.h:183
@ ssrc_any_outbound
Definition srtp.h:253
@ ssrc_specific
Definition srtp.h:249
@ ssrc_undefined
Definition srtp.h:248
@ ssrc_any_inbound
Definition srtp.h:250
@ sec_serv_conf_and_auth
Definition srtp.h:214
@ sec_serv_none
Definition srtp.h:211
@ sec_serv_conf
Definition srtp.h:212
@ sec_serv_auth
Definition srtp.h:213
srtp_err_status_t srtp_get_stream_roc(srtp_t session, uint32_t ssrc, uint32_t *roc)
srtp_get_stream_roc(session, ssrc, roc)
srtp_log_level_t
srtp_log_level_t defines log levels.
Definition srtp.h:1635
const char * srtp_get_version_string(void)
Returns the version string of the library.
unsigned int srtp_get_version(void)
Returns the numeric representation of the library version.
srtp_err_status_t srtp_install_log_handler(srtp_log_handler_func_t func, void *data)
sets the log handler to the function supplied by the caller.
srtp_err_status_t srtp_install_event_handler(srtp_event_handler_func_t func)
sets the event handler to the function supplied by the caller.
srtp_err_status_t srtp_list_debug_modules(void)
srtp_list_debug_modules() outputs a list of debugging modules
srtp_err_status_t srtp_set_debug_module(const char *mod_name, int v)
srtp_set_debug_module(mod_name, v)
srtp_err_status_t srtp_get_protect_trailer_length(srtp_t session, uint32_t use_mki, uint32_t mki_index, uint32_t *length)
srtp_get_protect_trailer_length(session, use_mki, mki_index, length)
void() srtp_event_handler_func_t(srtp_event_data_t *data)
srtp_event_handler_func_t is the function prototype for the event handler.
Definition srtp.h:1584
void() srtp_log_handler_func_t(srtp_log_level_t level, const char *msg, void *data)
srtp_log_handler_func_t is the function prototype for the log handler.
Definition srtp.h:1652
srtp_err_status_t srtp_get_protect_rtcp_trailer_length(srtp_t session, uint32_t use_mki, uint32_t mki_index, uint32_t *length)
srtp_get_protect_rtcp_trailer_length(session, use_mki, mki_index, length)
srtp_err_status_t srtp_set_stream_roc(srtp_t session, uint32_t ssrc, uint32_t roc)
srtp_set_stream_roc(session, ssrc, roc)
srtp_event_t
srtp_event_t defines events that need to be handled
Definition srtp.h:1550
@ srtp_log_level_debug
Definition srtp.h:1639
@ srtp_log_level_warning
Definition srtp.h:1637
@ srtp_log_level_error
Definition srtp.h:1636
@ srtp_log_level_info
Definition srtp.h:1638
@ event_ssrc_collision
Definition srtp.h:1551
@ event_key_soft_limit
Definition srtp.h:1552
@ event_packet_index_limit
Definition srtp.h:1556
@ event_key_hard_limit
Definition srtp.h:1554
void srtp_set_user_data(srtp_t ctx, void *data)
srtp_set_user_data() stores the given pointer into the SRTP session for later retrieval.
void * srtp_get_user_data(srtp_t ctx)
srtp_get_user_data() retrieves the pointer to the custom data previously stored with srtp_set_user_da...
srtp_crypto_policy_t describes a particular crypto policy that can be applied to an SRTP stream.
Definition srtp.h:226
srtp_auth_type_id_t auth_type
Definition srtp.h:231
srtp_sec_serv_t sec_serv
Definition srtp.h:237
int auth_tag_len
Definition srtp.h:235
int auth_key_len
Definition srtp.h:233
srtp_cipher_type_id_t cipher_type
Definition srtp.h:227
int cipher_key_len
Definition srtp.h:229
srtp_event_data_t is the structure passed as a callback to the event handler function
Definition srtp.h:1567
srtp_t session
Definition srtp.h:1568
srtp_event_t event
Definition srtp.h:1571
uint32_t ssrc
Definition srtp.h:1569
srtp_master_key_t represents a master key. There will be a Master Key Index and the Master Key associ...
Definition srtp.h:279
represents the policy for an SRTP session.
Definition srtp.h:311
void * deprecated_ekt
Definition srtp.h:322
int * enc_xtn_hdr
Definition srtp.h:333
int enc_xtn_hdr_count
Definition srtp.h:334
unsigned long num_master_keys
Definition srtp.h:321
struct srtp_policy_t * next
Definition srtp.h:336
srtp_crypto_policy_t rtp
Definition srtp.h:316
srtp_crypto_policy_t rtcp
Definition srtp.h:317
unsigned char * key
Definition srtp.h:318
unsigned long window_size
Definition srtp.h:324
srtp_ssrc_t ssrc
Definition srtp.h:312
int allow_repeat_tx
Definition srtp.h:326
An srtp_ssrc_t represents a particular SSRC value, or a ‘wildcard’ SSRC.
Definition srtp.h:267
srtp_ssrc_type_t type
Definition srtp.h:268
unsigned int value
Definition srtp.h:269