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authorErwin Nindl <nine@wirdorange.org>2007-06-22 13:59:20 +0000
committerErwin Nindl <nine@wirdorange.org>2007-06-22 13:59:20 +0000
commit0275479cb56c7f562f3513fef66c83fc44d1d8c9 (patch)
treef6fbb703cebf62d18b05e2a5e7591ac08c5b6702 /srtp/include/srtp_priv.h
parentsatp internet draft 00 final ietf version (diff)
added libsrtp to svn
Diffstat (limited to 'srtp/include/srtp_priv.h')
-rw-r--r--srtp/include/srtp_priv.h245
1 files changed, 245 insertions, 0 deletions
diff --git a/srtp/include/srtp_priv.h b/srtp/include/srtp_priv.h
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+/*
+ * srtp_priv.h
+ *
+ * private internal data structures and functions for 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_PRIV_H
+#define SRTP_PRIV_H
+
+#include "srtp.h"
+#include "rdbx.h"
+#include "rdb.h"
+#include "integers.h"
+
+/*
+ * 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 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
+
+
+/*
+ * the following declarations are libSRTP internal functions
+ */
+
+/*
+ * srtp_get_stream(ssrc) returns a pointer to the stream corresponding
+ * to ssrc, or NULL if no stream exists for that ssrc
+ */
+
+srtp_stream_t
+srtp_get_stream(srtp_t srtp, uint32_t ssrc);
+
+
+/*
+ * srtp_stream_init_keys(s, k) (re)initializes the srtp_stream_t s by
+ * deriving all of the needed keys using the KDF and the key k.
+ */
+
+
+err_status_t
+srtp_stream_init_keys(srtp_stream_t srtp, const void *key);
+
+/*
+ * libsrtp internal datatypes
+ */
+
+typedef enum direction_t {
+ dir_unknown = 0,
+ dir_srtp_sender = 1,
+ dir_srtp_receiver = 2
+} direction_t;
+
+/*
+ * an srtp_stream_t has its own SSRC, encryption key, authentication
+ * key, sequence number, and replay database
+ *
+ * note that the keys might not actually be unique, in which case the
+ * cipher_t and auth_t pointers will point to the same structures
+ */
+
+typedef struct srtp_stream_ctx_t {
+ uint32_t ssrc;
+ cipher_t *rtp_cipher;
+ auth_t *rtp_auth;
+ rdbx_t rtp_rdbx;
+ sec_serv_t rtp_services;
+ cipher_t *rtcp_cipher;
+ auth_t *rtcp_auth;
+ rdb_t rtcp_rdb;
+ sec_serv_t rtcp_services;
+ key_limit_ctx_t *limit;
+ direction_t direction;
+ struct srtp_stream_ctx_t *next; /* linked list of streams */
+} srtp_stream_ctx_t;
+
+
+/*
+ * an srtp_ctx_t holds a stream list and a service description
+ */
+
+typedef struct srtp_ctx_t {
+ srtp_stream_ctx_t *stream_list; /* linked list of streams */
+ srtp_stream_ctx_t *stream_template; /* act as template for other streams */
+} srtp_ctx_t;
+
+
+
+/*
+ * srtp_handle_event(srtp, srtm, evnt) calls the event handling
+ * function, if there is one.
+ *
+ * This macro is not included in the documentation as it is
+ * an internal-only function.
+ */
+
+#define srtp_handle_event(srtp, strm, evnt) \
+ if(srtp_event_handler) { \
+ srtp_event_data_t data; \
+ data.session = srtp; \
+ data.stream = strm; \
+ data.event = evnt; \
+ srtp_event_handler(&data); \
+}
+
+
+#endif /* SRTP_PRIV_H */