| /* |
| * srtp.h |
| * |
| * interface to libsrtp |
| * |
| * David A. McGrew |
| * Cisco Systems, Inc. |
| */ |
| /* |
| * |
| * Copyright (c) 2001-2006, Cisco Systems, Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * Neither the name of the Cisco Systems, Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, |
| * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| * OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| |
| #ifndef SRTP_H |
| #define SRTP_H |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| #include <stdint.h> |
| |
| /** |
| * @defgroup SRTP Secure RTP |
| * |
| * @brief libSRTP provides functions for protecting RTP and RTCP. See |
| * Section @ref Overview for an introduction to the use of the library. |
| * |
| * @{ |
| */ |
| |
| /* |
| * SRTP_MASTER_KEY_LEN is the nominal master key length supported by libSRTP |
| */ |
| |
| #define SRTP_MASTER_KEY_LEN 30 |
| |
| /* |
| * SRTP_MAX_KEY_LEN is the maximum key length supported by libSRTP |
| */ |
| #define SRTP_MAX_KEY_LEN 64 |
| |
| /* |
| * SRTP_MAX_TAG_LEN is the maximum tag length supported by libSRTP |
| */ |
| |
| #define SRTP_MAX_TAG_LEN 12 |
| |
| /** |
| * SRTP_MAX_TRAILER_LEN is the maximum length of the SRTP trailer |
| * (authentication tag and MKI) supported by libSRTP. This value is |
| * the maximum number of octets that will be added to an RTP packet by |
| * srtp_protect(). |
| * |
| * @brief the maximum number of octets added by srtp_protect(). |
| */ |
| #define SRTP_MAX_TRAILER_LEN SRTP_MAX_TAG_LEN |
| |
| /* |
| * SRTP_AEAD_SALT_LEN is the length of the SALT values used with |
| * GCM mode. GCM mode requires an IV. The SALT value is used |
| * as part of the IV formation logic applied to each RTP packet. |
| */ |
| #define SRTP_AEAD_SALT_LEN 12 |
| #define SRTP_AES_128_GCM_KEYSIZE_WSALT SRTP_AEAD_SALT_LEN + 16 |
| #define SRTP_AES_192_GCM_KEYSIZE_WSALT SRTP_AEAD_SALT_LEN + 24 |
| #define SRTP_AES_256_GCM_KEYSIZE_WSALT SRTP_AEAD_SALT_LEN + 32 |
| |
| /* |
| * an srtp_hdr_t represents the srtp header |
| * |
| * in this implementation, an srtp_hdr_t is assumed to be 32-bit aligned |
| * |
| * (note that this definition follows that of RFC 1889 Appendix A, but |
| * is not identical) |
| */ |
| |
| #ifndef WORDS_BIGENDIAN |
| |
| /* |
| * srtp_hdr_t represents an RTP or SRTP header. The bit-fields in |
| * this structure should be declared "unsigned int" instead of |
| * "unsigned char", but doing so causes the MS compiler to not |
| * fully pack the bit fields. |
| */ |
| |
| typedef struct { |
| unsigned char cc:4; /* CSRC count */ |
| unsigned char x:1; /* header extension flag */ |
| unsigned char p:1; /* padding flag */ |
| unsigned char version:2; /* protocol version */ |
| unsigned char pt:7; /* payload type */ |
| unsigned char m:1; /* marker bit */ |
| uint16_t seq; /* sequence number */ |
| uint32_t ts; /* timestamp */ |
| uint32_t ssrc; /* synchronization source */ |
| } srtp_hdr_t; |
| |
| #else /* BIG_ENDIAN */ |
| |
| typedef struct { |
| unsigned char version:2; /* protocol version */ |
| unsigned char p:1; /* padding flag */ |
| unsigned char x:1; /* header extension flag */ |
| unsigned char cc:4; /* CSRC count */ |
| unsigned char m:1; /* marker bit */ |
| unsigned char pt:7; /* payload type */ |
| uint16_t seq; /* sequence number */ |
| uint32_t ts; /* timestamp */ |
| uint32_t ssrc; /* synchronization source */ |
| } srtp_hdr_t; |
| |
| #endif |
| |
| typedef struct { |
| uint16_t profile_specific; /* profile-specific info */ |
| uint16_t length; /* number of 32-bit words in extension */ |
| } srtp_hdr_xtnd_t; |
| |
| |
| /* |
| * srtcp_hdr_t represents a secure rtcp header |
| * |
| * in this implementation, an srtcp header is assumed to be 32-bit |
| * alinged |
| */ |
| |
| #ifndef WORDS_BIGENDIAN |
| |
| typedef struct { |
| unsigned char rc:5; /* reception report count */ |
| unsigned char p:1; /* padding flag */ |
| unsigned char version:2; /* protocol version */ |
| unsigned char pt:8; /* payload type */ |
| uint16_t len; /* length */ |
| uint32_t ssrc; /* synchronization source */ |
| } srtcp_hdr_t; |
| |
| typedef struct { |
| unsigned int index:31; /* srtcp packet index in network order! */ |
| unsigned int e:1; /* encrypted? 1=yes */ |
| /* optional mikey/etc go here */ |
| /* and then the variable-length auth tag */ |
| } srtcp_trailer_t; |
| |
| |
| #else /* BIG_ENDIAN */ |
| |
| typedef struct { |
| unsigned char version:2; /* protocol version */ |
| unsigned char p:1; /* padding flag */ |
| unsigned char rc:5; /* reception report count */ |
| unsigned char pt:8; /* payload type */ |
| uint16_t len; /* length */ |
| uint32_t ssrc; /* synchronization source */ |
| } srtcp_hdr_t; |
| |
| typedef struct { |
| unsigned int version:2; /* protocol version */ |
| unsigned int p:1; /* padding flag */ |
| unsigned int count:5; /* varies by packet type */ |
| unsigned int pt:8; /* payload type */ |
| uint16_t length; /* len of uint32s of packet less header */ |
| } rtcp_common_t; |
| |
| typedef struct { |
| unsigned int e:1; /* encrypted? 1=yes */ |
| unsigned int index:31; /* srtcp packet index */ |
| /* optional mikey/etc go here */ |
| /* and then the variable-length auth tag */ |
| } srtcp_trailer_t; |
| |
| #endif |
| |
| |
| |
| /** |
| * @brief A srtp_cipher_type_id_t is an identifier for a particular cipher |
| * type. |
| * |
| * A srtp_cipher_type_id_t is an integer that represents a particular |
| * cipher type, e.g. the Advanced Encryption Standard (AES). A |
| * SRTP_NULL_CIPHER is avaliable; this cipher leaves the data unchanged, |
| * and can be selected to indicate that no encryption is to take |
| * place. |
| * |
| * @ingroup Ciphers |
| */ |
| typedef uint32_t srtp_cipher_type_id_t; |
| |
| /** |
| * @brief An srtp_auth_type_id_t is an identifier for a particular authentication |
| * function. |
| * |
| * An srtp_auth_type_id_t is an integer that represents a particular |
| * authentication function type, e.g. HMAC-SHA1. A SRTP_NULL_AUTH is |
| * avaliable; this authentication function performs no computation, |
| * and can be selected to indicate that no authentication is to take |
| * place. |
| * |
| * @ingroup Authentication |
| */ |
| typedef uint32_t srtp_auth_type_id_t; |
| |
| /* |
| * @brief srtp_err_status_t defines error codes. |
| * |
| * The enumeration srtp_err_status_t defines error codes. Note that the |
| * value of srtp_err_status_ok is equal to zero, which can simplify error |
| * checking somewhat. |
| * |
| */ |
| typedef enum { |
| srtp_err_status_ok = 0, /**< nothing to report */ |
| srtp_err_status_fail = 1, /**< unspecified failure */ |
| srtp_err_status_bad_param = 2, /**< unsupported parameter */ |
| srtp_err_status_alloc_fail = 3, /**< couldn't allocate memory */ |
| srtp_err_status_dealloc_fail = 4, /**< couldn't deallocate properly */ |
| srtp_err_status_init_fail = 5, /**< couldn't initialize */ |
| srtp_err_status_terminus = 6, /**< can't process as much data as requested */ |
| srtp_err_status_auth_fail = 7, /**< authentication failure */ |
| srtp_err_status_cipher_fail = 8, /**< cipher failure */ |
| srtp_err_status_replay_fail = 9, /**< replay check failed (bad index) */ |
| srtp_err_status_replay_old = 10, /**< replay check failed (index too old) */ |
| srtp_err_status_algo_fail = 11, /**< algorithm failed test routine */ |
| srtp_err_status_no_such_op = 12, /**< unsupported operation */ |
| srtp_err_status_no_ctx = 13, /**< no appropriate context found */ |
| srtp_err_status_cant_check = 14, /**< unable to perform desired validation */ |
| srtp_err_status_key_expired = 15, /**< can't use key any more */ |
| srtp_err_status_socket_err = 16, /**< error in use of socket */ |
| srtp_err_status_signal_err = 17, /**< error in use POSIX signals */ |
| srtp_err_status_nonce_bad = 18, /**< nonce check failed */ |
| srtp_err_status_read_fail = 19, /**< couldn't read data */ |
| srtp_err_status_write_fail = 20, /**< couldn't write data */ |
| srtp_err_status_parse_err = 21, /**< error parsing data */ |
| srtp_err_status_encode_err = 22, /**< error encoding data */ |
| srtp_err_status_semaphore_err = 23,/**< error while using semaphores */ |
| srtp_err_status_pfkey_err = 24 /**< error while using pfkey */ |
| } srtp_err_status_t; |
| |
| typedef struct srtp_stream_ctx_t_ srtp_stream_ctx_t; |
| typedef struct srtp_ctx_t_ srtp_ctx_t; |
| |
| /* |
| * nota bene: since libSRTP doesn't support the use of the MKI, the |
| * SRTP_MAX_TRAILER_LEN value is just the maximum tag length |
| */ |
| |
| /** |
| * @brief srtp_sec_serv_t describes a set of security services. |
| * |
| * A srtp_sec_serv_t enumeration is used to describe the particular |
| * security services that will be applied by a particular crypto |
| * policy (or other mechanism). |
| */ |
| |
| typedef enum { |
| sec_serv_none = 0, /**< no services */ |
| sec_serv_conf = 1, /**< confidentiality */ |
| sec_serv_auth = 2, /**< authentication */ |
| sec_serv_conf_and_auth = 3 /**< confidentiality and authentication */ |
| } srtp_sec_serv_t; |
| |
| /** |
| * @brief srtp_crypto_policy_t describes a particular crypto policy that |
| * can be applied to an SRTP stream. |
| * |
| * A srtp_crypto_policy_t describes a particular cryptographic policy that |
| * can be applied to an SRTP or SRTCP stream. An SRTP session policy |
| * consists of a list of these policies, one for each SRTP stream |
| * in the session. |
| */ |
| |
| typedef struct srtp_crypto_policy_t { |
| srtp_cipher_type_id_t cipher_type; /**< An integer representing |
| * the type of cipher. */ |
| int cipher_key_len; /**< The length of the cipher key |
| * in octets. */ |
| srtp_auth_type_id_t auth_type; /**< An integer representing the |
| * authentication function. */ |
| int auth_key_len; /**< The length of the authentication |
| * function key in octets. */ |
| int auth_tag_len; /**< The length of the authentication |
| * tag in octets. */ |
| srtp_sec_serv_t sec_serv; /**< The flag indicating the security |
| * services to be applied. */ |
| } srtp_crypto_policy_t; |
| |
| |
| /** |
| * @brief srtp_ssrc_type_t describes the type of an SSRC. |
| * |
| * An srtp_ssrc_type_t enumeration is used to indicate a type of SSRC. See |
| * @ref srtp_policy_t for more informataion. |
| */ |
| |
| typedef enum { |
| ssrc_undefined = 0, /**< Indicates an undefined SSRC type. */ |
| ssrc_specific = 1, /**< Indicates a specific SSRC value */ |
| ssrc_any_inbound = 2, /**< Indicates any inbound SSRC value |
| (i.e. a value that is used in the |
| function srtp_unprotect()) */ |
| ssrc_any_outbound = 3 /**< Indicates any outbound SSRC value |
| (i.e. a value that is used in the |
| function srtp_protect()) */ |
| } srtp_ssrc_type_t; |
| |
| /** |
| * @brief An srtp_ssrc_t represents a particular SSRC value, or a `wildcard' SSRC. |
| * |
| * An srtp_ssrc_t represents a particular SSRC value (if its type is |
| * ssrc_specific), or a wildcard SSRC value that will match all |
| * outbound SSRCs (if its type is ssrc_any_outbound) or all inbound |
| * SSRCs (if its type is ssrc_any_inbound). |
| * |
| */ |
| |
| typedef struct { |
| srtp_ssrc_type_t type; /**< The type of this particular SSRC */ |
| unsigned int value; /**< The value of this SSRC, if it is not a wildcard */ |
| } srtp_ssrc_t; |
| |
| |
| /** |
| * @brief points to an EKT policy |
| */ |
| typedef struct srtp_ekt_policy_ctx_t *srtp_ekt_policy_t; |
| |
| |
| /** |
| * @brief points to EKT stream data |
| */ |
| typedef struct srtp_ekt_stream_ctx_t *srtp_ekt_stream_t; |
| |
| |
| /** |
| * @brief represents the policy for an SRTP session. |
| * |
| * A single srtp_policy_t struct represents the policy for a single |
| * SRTP stream, and a linked list of these elements represents the |
| * policy for an entire SRTP session. Each element contains the SRTP |
| * and SRTCP crypto policies for that stream, a pointer to the SRTP |
| * master key for that stream, the SSRC describing that stream, or a |
| * flag indicating a `wildcard' SSRC value, and a `next' field that |
| * holds a pointer to the next element in the list of policy elements, |
| * or NULL if it is the last element. |
| * |
| * The wildcard value SSRC_ANY_INBOUND matches any SSRC from an |
| * inbound stream that for which there is no explicit SSRC entry in |
| * another policy element. Similarly, the value SSRC_ANY_OUTBOUND |
| * will matches any SSRC from an outbound stream that does not appear |
| * in another policy element. Note that wildcard SSRCs &b cannot be |
| * used to match both inbound and outbound traffic. This restriction |
| * is intentional, and it allows libSRTP to ensure that no security |
| * lapses result from accidental re-use of SSRC values during key |
| * sharing. |
| * |
| * |
| * @warning The final element of the list @b must have its `next' pointer |
| * set to NULL. |
| */ |
| |
| typedef struct srtp_policy_t { |
| srtp_ssrc_t ssrc; /**< The SSRC value of stream, or the |
| * flags SSRC_ANY_INBOUND or |
| * SSRC_ANY_OUTBOUND if key sharing |
| * is used for this policy element. |
| */ |
| srtp_crypto_policy_t rtp; /**< SRTP crypto policy. */ |
| srtp_crypto_policy_t rtcp; /**< SRTCP crypto policy. */ |
| unsigned char *key; /**< Pointer to the SRTP master key for |
| * this stream. */ |
| srtp_ekt_policy_t ekt; /**< Pointer to the EKT policy structure |
| * for this stream (if any) */ |
| unsigned long window_size; /**< The window size to use for replay |
| * protection. */ |
| int allow_repeat_tx; /**< Whether retransmissions of |
| * packets with the same sequence number |
| * are allowed. (Note that such repeated |
| * transmissions must have the same RTP |
| * payload, or a severe security weakness |
| * is introduced!) */ |
| struct srtp_policy_t *next; /**< Pointer to next stream policy. */ |
| } srtp_policy_t; |
| |
| |
| |
| |
| /** |
| * @brief An srtp_t points to an SRTP session structure. |
| * |
| * The typedef srtp_t is a pointer to a structure that represents |
| * an SRTP session. This datatype is intentially opaque in |
| * order to separate the interface from the implementation. |
| * |
| * An SRTP session consists of all of the traffic sent to the RTP and |
| * RTCP destination transport addresses, using the RTP/SAVP (Secure |
| * Audio/Video Profile). A session can be viewed as a set of SRTP |
| * streams, each of which originates with a different participant. |
| */ |
| |
| typedef srtp_ctx_t *srtp_t; |
| |
| |
| /** |
| * @brief An srtp_stream_t points to an SRTP stream structure. |
| * |
| * The typedef srtp_stream_t is a pointer to a structure that |
| * represents an SRTP stream. This datatype is intentionally |
| * opaque in order to separate the interface from the implementation. |
| * |
| * An SRTP stream consists of all of the traffic sent to an SRTP |
| * session by a single participant. A session can be viewed as |
| * a set of streams. |
| * |
| */ |
| typedef srtp_stream_ctx_t *srtp_stream_t; |
| |
| |
| |
| /** |
| * @brief srtp_init() initializes the srtp library. |
| * |
| * @warning This function @b must be called before any other srtp |
| * functions. |
| */ |
| |
| srtp_err_status_t srtp_init(void); |
| |
| /** |
| * @brief srtp_shutdown() de-initializes the srtp library. |
| * |
| * @warning No srtp functions may be called after calling this function. |
| */ |
| |
| srtp_err_status_t srtp_shutdown(void); |
| |
| /** |
| * @brief srtp_protect() is the Secure RTP sender-side packet processing |
| * function. |
| * |
| * The function call srtp_protect(ctx, rtp_hdr, len_ptr) applies SRTP |
| * protection to the RTP packet rtp_hdr (which has length *len_ptr) using |
| * the SRTP context ctx. If srtp_err_status_ok is returned, then rtp_hdr |
| * points to the resulting SRTP packet and *len_ptr is the number of |
| * octets in that packet; otherwise, no assumptions should be made |
| * about the value of either data elements. |
| * |
| * The sequence numbers of the RTP packets presented to this function |
| * need not be consecutive, but they @b must be out of order by less |
| * than 2^15 = 32,768 packets. |
| * |
| * @warning This function assumes that it can write the authentication |
| * tag into the location in memory immediately following the RTP |
| * packet, and assumes that the RTP packet is aligned on a 32-bit |
| * boundary. |
| * |
| * @warning This function assumes that it can write SRTP_MAX_TRAILER_LEN |
| * into the location in memory immediately following the RTP packet. |
| * Callers MUST ensure that this much writable memory is available in |
| * the buffer that holds the RTP packet. |
| * |
| * @param ctx is the SRTP context to use in processing the packet. |
| * |
| * @param rtp_hdr is a pointer to the RTP packet (before the call); after |
| * the function returns, it points to the srtp packet. |
| * |
| * @param len_ptr is a pointer to the length in octets of the complete |
| * RTP packet (header and body) before the function call, and of the |
| * complete SRTP packet after the call, if srtp_err_status_ok was returned. |
| * Otherwise, the value of the data to which it points is undefined. |
| * |
| * @return |
| * - srtp_err_status_ok no problems |
| * - srtp_err_status_replay_fail rtp sequence number was non-increasing |
| * - @e other failure in cryptographic mechanisms |
| */ |
| |
| srtp_err_status_t srtp_protect(srtp_t ctx, void *rtp_hdr, int *len_ptr); |
| |
| /** |
| * @brief srtp_unprotect() is the Secure RTP receiver-side packet |
| * processing function. |
| * |
| * The function call srtp_unprotect(ctx, srtp_hdr, len_ptr) verifies |
| * the Secure RTP protection of the SRTP packet pointed to by srtp_hdr |
| * (which has length *len_ptr), using the SRTP context ctx. If |
| * srtp_err_status_ok is returned, then srtp_hdr points to the resulting |
| * RTP packet and *len_ptr is the number of octets in that packet; |
| * otherwise, no assumptions should be made about the value of either |
| * data elements. |
| * |
| * The sequence numbers of the RTP packets presented to this function |
| * need not be consecutive, but they @b must be out of order by less |
| * than 2^15 = 32,768 packets. |
| * |
| * @warning This function assumes that the SRTP packet is aligned on a |
| * 32-bit boundary. |
| * |
| * @param ctx is the SRTP session which applies to the particular packet. |
| * |
| * @param srtp_hdr is a pointer to the header of the SRTP packet |
| * (before the call). after the function returns, it points to the |
| * rtp packet if srtp_err_status_ok was returned; otherwise, the value of |
| * the data to which it points is undefined. |
| * |
| * @param len_ptr is a pointer to the length in octets of the complete |
| * srtp packet (header and body) before the function call, and of the |
| * complete rtp packet after the call, if srtp_err_status_ok was returned. |
| * Otherwise, the value of the data to which it points is undefined. |
| * |
| * @return |
| * - srtp_err_status_ok if the RTP packet is valid. |
| * - srtp_err_status_auth_fail if the SRTP packet failed the message |
| * authentication check. |
| * - srtp_err_status_replay_fail if the SRTP packet is a replay (e.g. packet has |
| * already been processed and accepted). |
| * - [other] if there has been an error in the cryptographic mechanisms. |
| * |
| */ |
| |
| srtp_err_status_t srtp_unprotect(srtp_t ctx, void *srtp_hdr, int *len_ptr); |
| |
| |
| /** |
| * @brief srtp_create() allocates and initializes an SRTP session. |
| |
| * The function call srtp_create(session, policy, key) allocates and |
| * initializes an SRTP session context, applying the given policy and |
| * key. |
| * |
| * @param session is a pointer to the SRTP session to which the policy is |
| * to be added. |
| * |
| * @param policy is the srtp_policy_t struct that describes the policy |
| * for the session. The struct may be a single element, or it may be |
| * the head of a list, in which case each element of the list is |
| * processed. It may also be NULL, in which case streams should be added |
| * later using srtp_add_stream(). The final element of the list @b must |
| * have its `next' field set to NULL. |
| * |
| * @return |
| * - srtp_err_status_ok if creation succeded. |
| * - srtp_err_status_alloc_fail if allocation failed. |
| * - srtp_err_status_init_fail if initialization failed. |
| */ |
| |
| srtp_err_status_t srtp_create(srtp_t *session, const srtp_policy_t *policy); |
| |
| |
| /** |
| * @brief srtp_add_stream() allocates and initializes an SRTP stream |
| * within a given SRTP session. |
| * |
| * The function call srtp_add_stream(session, policy) allocates and |
| * initializes a new SRTP stream within a given, previously created |
| * session, applying the policy given as the other argument to that |
| * stream. |
| * |
| * @return values: |
| * - srtp_err_status_ok if stream creation succeded. |
| * - srtp_err_status_alloc_fail if stream allocation failed |
| * - srtp_err_status_init_fail if stream initialization failed. |
| */ |
| |
| srtp_err_status_t srtp_add_stream(srtp_t session, const srtp_policy_t *policy); |
| |
| |
| /** |
| * @brief srtp_remove_stream() deallocates an SRTP stream. |
| * |
| * The function call srtp_remove_stream(session, ssrc) removes |
| * the SRTP stream with the SSRC value ssrc from the SRTP session |
| * context given by the argument session. |
| * |
| * @param session is the SRTP session from which the stream |
| * will be removed. |
| * |
| * @param ssrc is the SSRC value of the stream to be removed. |
| * |
| * @warning Wildcard SSRC values cannot be removed from a |
| * session. |
| * |
| * @return |
| * - srtp_err_status_ok if the stream deallocation succeded. |
| * - [other] otherwise. |
| * |
| */ |
| |
| srtp_err_status_t srtp_remove_stream(srtp_t session, unsigned int ssrc); |
| |
| /** |
| * @brief srtp_crypto_policy_set_rtp_default() sets a crypto policy |
| * structure to the SRTP default policy for RTP protection. |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call crypto_policy_set_rtp_default(&p) sets the |
| * crypto_policy_t at location p to the SRTP default policy for RTP |
| * protection, as defined in the specification. This function is a |
| * convenience that helps to avoid dealing directly with the policy |
| * data structure. You are encouraged to initialize policy elements |
| * with this function call. Doing so may allow your code to be |
| * forward compatible with later versions of libSRTP that include more |
| * elements in the crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| |
| void srtp_crypto_policy_set_rtp_default(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_rtcp_default() sets a crypto policy |
| * structure to the SRTP default policy for RTCP protection. |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_rtcp_default(&p) sets the |
| * srtp_crypto_policy_t at location p to the SRTP default policy for RTCP |
| * protection, as defined in the specification. This function is a |
| * convenience that helps to avoid dealing directly with the policy |
| * data structure. You are encouraged to initialize policy elements |
| * with this function call. Doing so may allow your code to be |
| * forward compatible with later versions of libSRTP that include more |
| * elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| |
| void srtp_crypto_policy_set_rtcp_default(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80() sets a crypto |
| * policy structure to the SRTP default policy for RTP protection. |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80() is a |
| * synonym for srtp_crypto_policy_set_rtp_default(). It conforms to the |
| * naming convention used in RFC 4568 (SDP Security Descriptions for |
| * Media Streams). |
| * |
| * @return void. |
| * |
| */ |
| |
| #define srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(p) srtp_crypto_policy_set_rtp_default(p) |
| |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_cm_128_hmac_sha1_32() sets a crypto |
| * policy structure to a short-authentication tag policy |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_cm_128_hmac_sha1_32(&p) |
| * sets the srtp_crypto_policy_t at location p to use policy |
| * AES_CM_128_HMAC_SHA1_32 as defined in RFC 4568. |
| * This policy uses AES-128 |
| * Counter Mode encryption and HMAC-SHA1 authentication, with an |
| * authentication tag that is only 32 bits long. This length is |
| * considered adequate only for protecting audio and video media that |
| * use a stateless playback function. See Section 7.5 of RFC 3711 |
| * (http://www.ietf.org/rfc/rfc3711.txt). |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @warning This crypto policy is intended for use in SRTP, but not in |
| * SRTCP. It is recommended that a policy that uses longer |
| * authentication tags be used for SRTCP. See Section 7.5 of RFC 3711 |
| * (http://www.ietf.org/rfc/rfc3711.txt). |
| * |
| * @return void. |
| * |
| */ |
| |
| void srtp_crypto_policy_set_aes_cm_128_hmac_sha1_32(srtp_crypto_policy_t *p); |
| |
| |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_cm_128_null_auth() sets a crypto |
| * policy structure to an encryption-only policy |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_cm_128_null_auth(&p) sets |
| * the srtp_crypto_policy_t at location p to use the SRTP default cipher |
| * (AES-128 Counter Mode), but to use no authentication method. This |
| * policy is NOT RECOMMENDED unless it is unavoidable; see Section 7.5 |
| * of RFC 3711 (http://www.ietf.org/rfc/rfc3711.txt). |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @warning This policy is NOT RECOMMENDED for SRTP unless it is |
| * unavoidable, and it is NOT RECOMMENDED at all for SRTCP; see |
| * Section 7.5 of RFC 3711 (http://www.ietf.org/rfc/rfc3711.txt). |
| * |
| * @return void. |
| * |
| */ |
| |
| void srtp_crypto_policy_set_aes_cm_128_null_auth(srtp_crypto_policy_t *p); |
| |
| |
| /** |
| * @brief srtp_crypto_policy_set_null_cipher_hmac_sha1_80() sets a crypto |
| * policy structure to an authentication-only policy |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_null_cipher_hmac_sha1_80(&p) |
| * sets the srtp_crypto_policy_t at location p to use HMAC-SHA1 with an 80 |
| * bit authentication tag to provide message authentication, but to |
| * use no encryption. This policy is NOT RECOMMENDED for SRTP unless |
| * there is a requirement to forego encryption. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @warning This policy is NOT RECOMMENDED for SRTP unless there is a |
| * requirement to forego encryption. |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_null_cipher_hmac_sha1_80(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_null_cipher_hmac_null() sets a crypto |
| * policy structure to use no encryption or authentication. |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_null_cipher_hmac_null(&p) |
| * sets the srtp_crypto_policy_t at location p to use no encryption and |
| * no authentication. This policy should only be used for testing and |
| * troubleshootingl. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @warning This policy is NOT RECOMMENDED for SRTP unless there is a |
| * requirement to forego encryption and authentication. |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_null_cipher_hmac_null(srtp_crypto_policy_t *p); |
| |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_cm_256_hmac_sha1_80() sets a crypto |
| * policy structure to a encryption and authentication policy using AES-256 |
| * for RTP protection. |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_cm_256_hmac_sha1_80(&p) |
| * sets the srtp_crypto_policy_t at location p to use policy |
| * AES_CM_256_HMAC_SHA1_80 as defined in |
| * draft-ietf-avt-srtp-big-aes-03.txt. This policy uses AES-256 |
| * Counter Mode encryption and HMAC-SHA1 authentication, with an 80 bit |
| * authentication tag. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| |
| void srtp_crypto_policy_set_aes_cm_256_hmac_sha1_80(srtp_crypto_policy_t *p); |
| |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_cm_256_hmac_sha1_32() sets a crypto |
| * policy structure to a short-authentication tag policy using AES-256 |
| * encryption. |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_cm_256_hmac_sha1_32(&p) |
| * sets the srtp_crypto_policy_t at location p to use policy |
| * AES_CM_256_HMAC_SHA1_32 as defined in |
| * draft-ietf-avt-srtp-big-aes-03.txt. This policy uses AES-256 |
| * Counter Mode encryption and HMAC-SHA1 authentication, with an |
| * authentication tag that is only 32 bits long. This length is |
| * considered adequate only for protecting audio and video media that |
| * use a stateless playback function. See Section 7.5 of RFC 3711 |
| * (http://www.ietf.org/rfc/rfc3711.txt). |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @warning This crypto policy is intended for use in SRTP, but not in |
| * SRTCP. It is recommended that a policy that uses longer |
| * authentication tags be used for SRTCP. See Section 7.5 of RFC 3711 |
| * (http://www.ietf.org/rfc/rfc3711.txt). |
| * |
| * @return void. |
| * |
| */ |
| |
| void srtp_crypto_policy_set_aes_cm_256_hmac_sha1_32(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_cm_256_null_auth() sets a crypto |
| * policy structure to an encryption-only policy |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_cm_256_null_auth(&p) sets |
| * the srtp_crypto_policy_t at location p to use the SRTP default cipher |
| * (AES-256 Counter Mode), but to use no authentication method. This |
| * policy is NOT RECOMMENDED unless it is unavoidable; see Section 7.5 |
| * of RFC 3711 (http://www.ietf.org/rfc/rfc3711.txt). |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @warning This policy is NOT RECOMMENDED for SRTP unless it is |
| * unavoidable, and it is NOT RECOMMENDED at all for SRTCP; see |
| * Section 7.5 of RFC 3711 (http://www.ietf.org/rfc/rfc3711.txt). |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_aes_cm_256_null_auth(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_gcm_128_8_auth() sets a crypto |
| * policy structure to an AEAD encryption policy. |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_gcm_128_8_auth(&p) sets |
| * the srtp_crypto_policy_t at location p to use the SRTP default cipher |
| * (AES-128 Galois Counter Mode) with 8 octet auth tag. This |
| * policy applies confidentiality and authentication to both the |
| * RTP and RTCP packets. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_aes_gcm_128_8_auth(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_gcm_256_8_auth() sets a crypto |
| * policy structure to an AEAD encryption policy |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_gcm_256_8_auth(&p) sets |
| * the srtp_crypto_policy_t at location p to use the SRTP default cipher |
| * (AES-256 Galois Counter Mode) with 8 octet auth tag. This |
| * policy applies confidentiality and authentication to both the |
| * RTP and RTCP packets. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_aes_gcm_256_8_auth(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_gcm_128_8_only_auth() sets a crypto |
| * policy structure to an AEAD authentication-only policy |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_gcm_128_8_only_auth(&p) sets |
| * the srtp_crypto_policy_t at location p to use the SRTP default cipher |
| * (AES-128 Galois Counter Mode) with 8 octet auth tag. This policy |
| * applies confidentiality and authentication to the RTP packets, |
| * but only authentication to the RTCP packets. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_aes_gcm_128_8_only_auth(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_gcm_256_8_only_auth() sets a crypto |
| * policy structure to an AEAD authentication-only policy |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_gcm_256_8_only_auth(&p) sets |
| * the srtp_crypto_policy_t at location p to use the SRTP default cipher |
| * (AES-256 Galois Counter Mode) with 8 octet auth tag. This policy |
| * applies confidentiality and authentication to the RTP packets, |
| * but only authentication to the RTCP packets. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_aes_gcm_256_8_only_auth(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_gcm_128_16_auth() sets a crypto |
| * policy structure to an AEAD encryption policy. |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_gcm_128_16_auth(&p) sets |
| * the srtp_crypto_policy_t at location p to use the SRTP default cipher |
| * (AES-128 Galois Counter Mode) with 16 octet auth tag. This |
| * policy applies confidentiality and authentication to both the |
| * RTP and RTCP packets. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_aes_gcm_128_16_auth(srtp_crypto_policy_t *p); |
| |
| /** |
| * @brief srtp_crypto_policy_set_aes_gcm_256_16_auth() sets a crypto |
| * policy structure to an AEAD encryption policy |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_aes_gcm_256_16_auth(&p) sets |
| * the srtp_crypto_policy_t at location p to use the SRTP default cipher |
| * (AES-256 Galois Counter Mode) with 16 octet auth tag. This |
| * policy applies confidentiality and authentication to both the |
| * RTP and RTCP packets. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return void. |
| * |
| */ |
| void srtp_crypto_policy_set_aes_gcm_256_16_auth(srtp_crypto_policy_t *p); |
| |
| |
| /** |
| * @brief srtp_dealloc() deallocates storage for an SRTP session |
| * context. |
| * |
| * The function call srtp_dealloc(s) deallocates storage for the |
| * SRTP session context s. This function should be called no more |
| * than one time for each of the contexts allocated by the function |
| * srtp_create(). |
| * |
| * @param s is the srtp_t for the session to be deallocated. |
| * |
| * @return |
| * - srtp_err_status_ok if there no problems. |
| * - srtp_err_status_dealloc_fail a memory deallocation failure occured. |
| */ |
| |
| srtp_err_status_t srtp_dealloc(srtp_t s); |
| |
| |
| /* |
| * @brief identifies a particular SRTP profile |
| * |
| * An srtp_profile_t enumeration is used to identify a particular SRTP |
| * profile (that is, a set of algorithms and parameters). These |
| * profiles are defined in the DTLS-SRTP draft. |
| */ |
| |
| typedef enum { |
| srtp_profile_reserved = 0, |
| srtp_profile_aes128_cm_sha1_80 = 1, |
| srtp_profile_aes128_cm_sha1_32 = 2, |
| srtp_profile_aes256_cm_sha1_80 = 3, |
| srtp_profile_aes256_cm_sha1_32 = 4, |
| srtp_profile_null_sha1_80 = 5, |
| srtp_profile_null_sha1_32 = 6, |
| } srtp_profile_t; |
| |
| |
| /** |
| * @brief srtp_crypto_policy_set_from_profile_for_rtp() sets a crypto policy |
| * structure to the appropriate value for RTP based on an srtp_profile_t |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_rtp_default(&policy, profile) |
| * sets the srtp_crypto_policy_t at location policy to the policy for RTP |
| * protection, as defined by the srtp_profile_t profile. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return values |
| * - srtp_err_status_ok no problems were encountered |
| * - srtp_err_status_bad_param the profile is not supported |
| * |
| */ |
| srtp_err_status_t srtp_crypto_policy_set_from_profile_for_rtp(srtp_crypto_policy_t *policy, srtp_profile_t profile); |
| |
| |
| |
| |
| /** |
| * @brief srtp_crypto_policy_set_from_profile_for_rtcp() sets a crypto policy |
| * structure to the appropriate value for RTCP based on an srtp_profile_t |
| * |
| * @param p is a pointer to the policy structure to be set |
| * |
| * The function call srtp_crypto_policy_set_rtcp_default(&policy, profile) |
| * sets the srtp_crypto_policy_t at location policy to the policy for RTCP |
| * protection, as defined by the srtp_profile_t profile. |
| * |
| * This function is a convenience that helps to avoid dealing directly |
| * with the policy data structure. You are encouraged to initialize |
| * policy elements with this function call. Doing so may allow your |
| * code to be forward compatible with later versions of libSRTP that |
| * include more elements in the srtp_crypto_policy_t datatype. |
| * |
| * @return values |
| * - srtp_err_status_ok no problems were encountered |
| * - srtp_err_status_bad_param the profile is not supported |
| * |
| */ |
| srtp_err_status_t srtp_crypto_policy_set_from_profile_for_rtcp(srtp_crypto_policy_t *policy, srtp_profile_t profile); |
| |
| /** |
| * @brief returns the master key length for a given SRTP profile |
| */ |
| unsigned int |
| srtp_profile_get_master_key_length(srtp_profile_t profile); |
| |
| |
| /** |
| * @brief returns the master salt length for a given SRTP profile |
| */ |
| unsigned int |
| srtp_profile_get_master_salt_length(srtp_profile_t profile); |
| |
| /** |
| * @brief appends the salt to the key |
| * |
| * The function call srtp_append_salt_to_key(k, klen, s, slen) |
| * copies the string s to the location at klen bytes following |
| * the location k. |
| * |
| * @warning There must be at least bytes_in_salt + bytes_in_key bytes |
| * available at the location pointed to by key. |
| * |
| */ |
| |
| void |
| srtp_append_salt_to_key(unsigned char *key, unsigned int bytes_in_key, |
| unsigned char *salt, unsigned int bytes_in_salt); |
| |
| |
| |
| /** |
| * @} |
| */ |
| |
| |
| |
| /** |
| * @defgroup SRTCP Secure RTCP |
| * @ingroup SRTP |
| * |
| * @brief Secure RTCP functions are used to protect RTCP traffic. |
| * |
| * RTCP is the control protocol for RTP. libSRTP protects RTCP |
| * traffic in much the same way as it does RTP traffic. The function |
| * srtp_protect_rtcp() applies cryptographic protections to outbound |
| * RTCP packets, and srtp_unprotect_rtcp() verifies the protections on |
| * inbound RTCP packets. |
| * |
| * A note on the naming convention: srtp_protect_rtcp() has an srtp_t |
| * as its first argument, and thus has `srtp_' as its prefix. The |
| * trailing `_rtcp' indicates the protocol on which it acts. |
| * |
| * @{ |
| */ |
| |
| /** |
| * @brief srtp_protect_rtcp() is the Secure RTCP sender-side packet |
| * processing function. |
| * |
| * The function call srtp_protect_rtcp(ctx, rtp_hdr, len_ptr) applies |
| * SRTCP protection to the RTCP packet rtcp_hdr (which has length |
| * *len_ptr) using the SRTP session context ctx. If srtp_err_status_ok is |
| * returned, then rtp_hdr points to the resulting SRTCP packet and |
| * *len_ptr is the number of octets in that packet; otherwise, no |
| * assumptions should be made about the value of either data elements. |
| * |
| * @warning This function assumes that it can write the authentication |
| * tag into the location in memory immediately following the RTCP |
| * packet, and assumes that the RTCP packet is aligned on a 32-bit |
| * boundary. |
| * |
| * @warning This function assumes that it can write SRTP_MAX_TRAILER_LEN+4 |
| * into the location in memory immediately following the RTCP packet. |
| * Callers MUST ensure that this much writable memory is available in |
| * the buffer that holds the RTCP packet. |
| * |
| * @param ctx is the SRTP context to use in processing the packet. |
| * |
| * @param rtcp_hdr is a pointer to the RTCP packet (before the call); after |
| * the function returns, it points to the srtp packet. |
| * |
| * @param pkt_octet_len is a pointer to the length in octets of the |
| * complete RTCP packet (header and body) before the function call, |
| * and of the complete SRTCP packet after the call, if srtp_err_status_ok |
| * was returned. Otherwise, the value of the data to which it points |
| * is undefined. |
| * |
| * @return |
| * - srtp_err_status_ok if there were no problems. |
| * - [other] if there was a failure in |
| * the cryptographic mechanisms. |
| */ |
| |
| |
| srtp_err_status_t srtp_protect_rtcp(srtp_t ctx, void *rtcp_hdr, int *pkt_octet_len); |
| |
| /** |
| * @brief srtp_unprotect_rtcp() is the Secure RTCP receiver-side packet |
| * processing function. |
| * |
| * The function call srtp_unprotect_rtcp(ctx, srtp_hdr, len_ptr) |
| * verifies the Secure RTCP protection of the SRTCP packet pointed to |
| * by srtcp_hdr (which has length *len_ptr), using the SRTP session |
| * context ctx. If srtp_err_status_ok is returned, then srtcp_hdr points |
| * to the resulting RTCP packet and *len_ptr is the number of octets |
| * in that packet; otherwise, no assumptions should be made about the |
| * value of either data elements. |
| * |
| * @warning This function assumes that the SRTCP packet is aligned on a |
| * 32-bit boundary. |
| * |
| * @param ctx is a pointer to the srtp_t which applies to the |
| * particular packet. |
| * |
| * @param srtcp_hdr is a pointer to the header of the SRTCP packet |
| * (before the call). After the function returns, it points to the |
| * rtp packet if srtp_err_status_ok was returned; otherwise, the value of |
| * the data to which it points is undefined. |
| * |
| * @param pkt_octet_len is a pointer to the length in octets of the |
| * complete SRTCP packet (header and body) before the function call, |
| * and of the complete rtp packet after the call, if srtp_err_status_ok was |
| * returned. Otherwise, the value of the data to which it points is |
| * undefined. |
| * |
| * @return |
| * - srtp_err_status_ok if the RTCP packet is valid. |
| * - srtp_err_status_auth_fail if the SRTCP packet failed the message |
| * authentication check. |
| * - srtp_err_status_replay_fail if the SRTCP packet is a replay (e.g. has |
| * already been processed and accepted). |
| * - [other] if there has been an error in the cryptographic mechanisms. |
| * |
| */ |
| |
| srtp_err_status_t srtp_unprotect_rtcp(srtp_t ctx, void *srtcp_hdr, int *pkt_octet_len); |
| |
| /** |
| * @} |
| */ |
| |
| |
| /** |
| * @defgroup User data associated to a SRTP session. |
| * @ingroup SRTP |
| * |
| * @brief Store custom user data within a SRTP session. |
| * |
| * @{ |
| */ |
| |
| /** |
| * @brief srtp_set_user_data() stores the given pointer into the SRTP |
| * session for later retrieval. |
| * |
| * @param ctx is the srtp_t context in which the given data pointer is |
| * stored. |
| * |
| * @param data is a pointer to the custom information (struct, function, |
| * etc) associated with the SRTP session. |
| * |
| * @return void. |
| * |
| */ |
| |
| void |
| srtp_set_user_data(srtp_t ctx, void *data); |
| |
| /** |
| * @brief srtp_get_user_data() retrieves the pointer to the custom data |
| * previously stored with srtp_set_user_data(). |
| * |
| * This function is mostly useful for retrieving data associated to a |
| * SRTP session when an event fires. The user can then get such a custom |
| * data by calling this function with the session field of the |
| * srtp_event_data_t struct as argument. |
| * |
| * @param ctx is the srtp_t context in which the given data pointer was |
| * stored. |
| * |
| * @return void* pointer to the user data. |
| * |
| */ |
| |
| void* |
| srtp_get_user_data(srtp_t ctx); |
| |
| /** |
| * @} |
| */ |
| |
| |
| /** |
| * @defgroup SRTPevents SRTP events and callbacks |
| * @ingroup SRTP |
| * |
| * @brief libSRTP can use a user-provided callback function to |
| * handle events. |
| * |
| * |
| * libSRTP allows a user to provide a callback function to handle |
| * events that need to be dealt with outside of the data plane (see |
| * the enum srtp_event_t for a description of these events). Dealing |
| * with these events is not a strict necessity; they are not |
| * security-critical, but the application may suffer if they are not |
| * handled. The function srtp_set_event_handler() is used to provide |
| * the callback function. |
| * |
| * A default event handler that merely reports on the events as they |
| * happen is included. It is also possible to set the event handler |
| * function to NULL, in which case all events will just be silently |
| * ignored. |
| * |
| * @{ |
| */ |
| |
| /** |
| * @brief srtp_event_t defines events that need to be handled |
| * |
| * The enum srtp_event_t defines events that need to be handled |
| * outside the `data plane', such as SSRC collisions and |
| * key expirations. |
| * |
| * When a key expires or the maximum number of packets has been |
| * reached, an SRTP stream will enter an `expired' state in which no |
| * more packets can be protected or unprotected. When this happens, |
| * it is likely that you will want to either deallocate the stream |
| * (using srtp_stream_dealloc()), and possibly allocate a new one. |
| * |
| * When an SRTP stream expires, the other streams in the same session |
| * are unaffected, unless key sharing is used by that stream. In the |
| * latter case, all of the streams in the session will expire. |
| */ |
| |
| typedef enum { |
| event_ssrc_collision, /**< |
| * An SSRC collision occured. |
| */ |
| event_key_soft_limit, /**< An SRTP stream reached the soft key |
| * usage limit and will expire soon. |
| */ |
| event_key_hard_limit, /**< An SRTP stream reached the hard |
| * key usage limit and has expired. |
| */ |
| event_packet_index_limit /**< An SRTP stream reached the hard |
| * packet limit (2^48 packets). |
| */ |
| } srtp_event_t; |
| |
| /** |
| * @brief srtp_event_data_t is the structure passed as a callback to |
| * the event handler function |
| * |
| * The struct srtp_event_data_t holds the data passed to the event |
| * handler function. |
| */ |
| |
| typedef struct srtp_event_data_t { |
| srtp_t session; /**< The session in which the event happend. */ |
| srtp_stream_t stream; /**< The stream in which the event happend. */ |
| srtp_event_t event; /**< An enum indicating the type of event. */ |
| } srtp_event_data_t; |
| |
| /** |
| * @brief srtp_event_handler_func_t is the function prototype for |
| * the event handler. |
| * |
| * The typedef srtp_event_handler_func_t is the prototype for the |
| * event handler function. It has as its only argument an |
| * srtp_event_data_t which describes the event that needs to be handled. |
| * There can only be a single, global handler for all events in |
| * libSRTP. |
| */ |
| |
| typedef void (srtp_event_handler_func_t)(srtp_event_data_t *data); |
| |
| /** |
| * @brief sets the event handler to the function supplied by the caller. |
| * |
| * The function call srtp_install_event_handler(func) sets the event |
| * handler function to the value func. The value NULL is acceptable |
| * as an argument; in this case, events will be ignored rather than |
| * handled. |
| * |
| * @param func is a pointer to a fuction that takes an srtp_event_data_t |
| * pointer as an argument and returns void. This function |
| * will be used by libSRTP to handle events. |
| */ |
| |
| srtp_err_status_t srtp_install_event_handler(srtp_event_handler_func_t func); |
| |
| /** |
| * @brief Returns the version string of the library. |
| * |
| */ |
| const char *srtp_get_version_string(void); |
| |
| /** |
| * @brief Returns the numeric representation of the library version. |
| * |
| */ |
| unsigned int srtp_get_version(void); |
| |
| /** |
| * @brief srtp_set_debug_module(mod_name, v) |
| * |
| * sets dynamic debugging to the value v (0 for off, 1 for on) for the |
| * debug module with the name mod_name |
| * |
| * returns err_status_ok on success, err_status_fail otherwise |
| */ |
| srtp_err_status_t srtp_set_debug_module(char *mod_name, int v); |
| |
| /** |
| * @brief srtp_list_debug_modules() outputs a list of debugging modules |
| * |
| */ |
| srtp_err_status_t srtp_list_debug_modules(void); |
| |
| |
| /** |
| * @} |
| */ |
| /* in host order, so outside the #if */ |
| #define SRTCP_E_BIT 0x80000000 |
| /* for byte-access */ |
| #define SRTCP_E_BYTE_BIT 0x80 |
| #define SRTCP_INDEX_MASK 0x7fffffff |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* SRTP_H */ |