Land https://codereview.chromium.org/889083003/ to update libsrtp to upstream 1.5.0

srtp/include/srtp.h

 /*
  * srtp.h
  *
  * interface to libsrtp
  *
  * David A. McGrew
  * Cisco Systems, Inc.
  */
 /*
  *      
@@ skipping 32 matching lines @@
  */
 
 
 #ifndef SRTP_H
 #define SRTP_H
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#include "crypto_kernel.h" 
+#include <stdint.h>
+#include "crypto.h" 
+#include "crypto_types.h"
+#include "err.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.
  *
  * @{
  */
 
@@ skipping 17 matching lines @@
 /**
  * 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 AES_128_GCM_KEYSIZE_WSALT   SRTP_AEAD_SALT_LEN + 16
+#define AES_192_GCM_KEYSIZE_WSALT   SRTP_AEAD_SALT_LEN + 24
+#define AES_256_GCM_KEYSIZE_WSALT   SRTP_AEAD_SALT_LEN + 32
+
+
+
 /* 
  * 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 sec_serv_t describes a set of security services. 
  *
  * A sec_serv_t enumeration is used to describe the particular
  * security services that will be applied by a particular crypto
@@ skipping 196 matching lines @@
  * 
  * 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 err_status_ok was returned.
  * Otherwise, the value of the data to which it points is undefined.
  *
@@ skipping 18 matching lines @@
  * 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 a pointer to the srtp_t which applies to the
- * particular packet.
+ * @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 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 err_status_ok was returned.
  * Otherwise, the value of the data to which it points is undefined.
@@ skipping 12 matching lines @@
 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 the SRTP session to which the policy is to be added.
+ * @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
  *    - err_status_ok           if creation succeded.
@@ skipping 261 matching lines @@
  * authentication tags be used for SRTCP.  See Section 7.5 of RFC 3711
  * (http://www.ietf.org/rfc/rfc3711.txt).
  *
  * @return void.
  * 
  */
 
 void
 crypto_policy_set_aes_cm_256_hmac_sha1_32(crypto_policy_t *p);
 
+/**
+ * @brief 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 crypto_policy_set_aes_cm_256_null_auth(&p) sets
+ * the 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 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
+crypto_policy_set_aes_cm_256_null_auth(crypto_policy_t *p);
+
+/**
+ * @brief 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 crypto_policy_set_aes_gcm_128_8_auth(&p) sets
+ * the 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 crypto_policy_t datatype.
+ *
+ * @return void.
+ * 
+ */
+void
+crypto_policy_set_aes_gcm_128_8_auth(crypto_policy_t *p);
+
+/**
+ * @brief 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 crypto_policy_set_aes_gcm_256_8_auth(&p) sets
+ * the 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 crypto_policy_t datatype.
+ *
+ * @return void.
+ * 
+ */
+void
+crypto_policy_set_aes_gcm_256_8_auth(crypto_policy_t *p);
+
+/**
+ * @brief 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 crypto_policy_set_aes_gcm_128_8_only_auth(&p) sets
+ * the 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 crypto_policy_t datatype.
+ *
+ * @return void.
+ * 
+ */
+void
+crypto_policy_set_aes_gcm_128_8_only_auth(crypto_policy_t *p);
+
+/**
+ * @brief 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 crypto_policy_set_aes_gcm_256_8_only_auth(&p) sets
+ * the 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 crypto_policy_t datatype.
+ *
+ * @return void.
+ * 
+ */
+void
+crypto_policy_set_aes_gcm_256_8_only_auth(crypto_policy_t *p);
+
+/**
+ * @brief 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 crypto_policy_set_aes_gcm_128_16_auth(&p) sets
+ * the 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 crypto_policy_t datatype.
+ *
+ * @return void.
+ * 
+ */
+void
+crypto_policy_set_aes_gcm_128_16_auth(crypto_policy_t *p);
+
+/**
+ * @brief 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 crypto_policy_set_aes_gcm_256_16_auth(&p) sets
+ * the 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 crypto_policy_t datatype.
+ *
+ * @return void.
+ * 
+ */
+void
+crypto_policy_set_aes_gcm_256_16_auth(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().
  *
@@ skipping 145 matching lines @@
  * *len_ptr) using the SRTP session context ctx.  If 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 err_status_ok
  * was returned.  Otherwise, the value of the data to which it points
  * is undefined.
@@ skipping 47 matching lines @@
  *
  */
 
 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
@@ skipping 81 matching lines @@
  *
  * @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.
  */
 
 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);
+
+/**
  * @}
  */
 /* 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 */