Added support for set and get the roll-over-counter

Author: ulfolsson

crypto/include/rdbx.h

@@ -85,6 +85,7 @@ typedef uint64_t srtp_xtd_seq_num_t;
 typedef struct {
     srtp_xtd_seq_num_t index;
     bitvector_t bitmask;
+    int is_roc_set;
 } srtp_rdbx_t;
 
 

crypto/replay/rdbx.c

@@ -194,6 +194,7 @@ srtp_err_status_t srtp_rdbx_init (srtp_rdbx_t *rdbx, unsigned long ws)
     }
 
     srtp_index_init(&rdbx->index);
+    rdbx->is_roc_set = 0;
 
     return srtp_err_status_ok;
 }
@@ -232,6 +233,8 @@ srtp_err_status_t srtp_rdbx_set_roc (srtp_rdbx_t *rdbx, uint32_t roc)
     rdbx->index |= ((uint64_t)roc) << 16; /* set ROC */
 #endif
 
+    rdbx->is_roc_set = 1;
+
     return srtp_err_status_ok;
 }
 

include/srtp.h

@@ -1854,6 +1854,29 @@ srtp_err_status_t srtp_get_protect_rtcp_trailer_length(srtp_t session, uint32_t
                                                        uint32_t mki_index, uint32_t *length);
 
 
+/**
+ * @brief srtp_set_stream_roc(session, ssrc, roc)
+ *
+ * Set the roll-over-counter on a session for a given SSRC
+ *
+ * returns err_status_ok on success, srtp_err_status_bad_param if there is no
+ * stream found
+ *
+ */
+srtp_err_status_t srtp_set_stream_roc(srtp_t session, uint32_t ssrc, uint32_t roc);
+
+/**
+ * @brief srtp_get_stream_roc(session, ssrc, roc)
+ *
+ * Get the roll-over-counter on a session for a given SSRC
+ *
+ * returns err_status_ok on success, srtp_err_status_bad_param if there is no
+ * stream found
+ *
+ */
+srtp_err_status_t srtp_get_stream_roc(srtp_t session, uint32_t ssrc, uint32_t *roc);
+
+
 /**
  * @}
  */

srtp/srtp.c

@@ -2251,8 +2251,14 @@ srtp_unprotect_mki(srtp_ctx_t *ctx, void *srtp_hdr, int *pkt_octet_len,
     }
   } else {
 
-    /* estimate packet index from seq. num. in header */
-    delta = srtp_rdbx_estimate_index(&stream->rtp_rdbx, &est, ntohs(hdr->seq));
+    if (stream->rtp_rdbx.is_roc_set) {
+        est = (srtp_xtd_seq_num_t) ntohs(hdr->seq) + stream->rtp_rdbx.index;
+        delta = (int)est;
+        stream->rtp_rdbx.is_roc_set = 0;
+    } else {
+        /* estimate packet index from seq. num. in header */
+        delta = srtp_rdbx_estimate_index(&stream->rtp_rdbx, &est, ntohs(hdr->seq));
+    }
 
     /* check replay database */
     status = srtp_rdbx_check(&stream->rtp_rdbx, delta);
@@ -4461,3 +4467,27 @@ srtp_err_status_t srtp_install_log_handler(srtp_log_handler_func_t func, void *
     }
     return srtp_err_status_ok;
 }
+
+srtp_err_status_t
+srtp_set_stream_roc(srtp_t session, uint32_t ssrc, uint32_t roc) {
+    srtp_stream_t stream;
+
+    stream = srtp_get_stream(session, htonl(ssrc));
+    if (stream == NULL)
+        return srtp_err_status_bad_param;
+
+    return srtp_rdbx_set_roc(&stream->rtp_rdbx, roc);
+}
+
+srtp_err_status_t
+srtp_get_stream_roc(srtp_t session, uint32_t ssrc, uint32_t *roc) {
+    srtp_stream_t stream;
+
+    stream = srtp_get_stream(session, htonl(ssrc));
+    if (stream == NULL)
+        return srtp_err_status_bad_param;
+
+    *roc = stream->rtp_rdbx.index >> 16;
+
+    return srtp_err_status_ok;
+}