Index: libsrtp/crypto/kernel/key.c |
=================================================================== |
--- libsrtp/crypto/kernel/key.c (revision 0) |
+++ libsrtp/crypto/kernel/key.c (revision 0) |
@@ -0,0 +1,115 @@ |
+/* |
+ * key.c |
+ * |
+ * key usage limits enforcement |
+ * |
+ * 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. |
+ * |
+ */ |
+ |
+#include "key.h" |
+ |
+#define soft_limit 0x10000 |
+ |
+err_status_t |
+key_limit_set(key_limit_t key, const xtd_seq_num_t s) { |
+#ifdef NO_64BIT_MATH |
+ if (high32(s) == 0 && low32(s) < soft_limit) |
+ return err_status_bad_param; |
+#else |
+ if (s < soft_limit) |
+ return err_status_bad_param; |
+#endif |
+ key->num_left = s; |
+ key->state = key_state_normal; |
+ return err_status_ok; |
+} |
+ |
+err_status_t |
+key_limit_clone(key_limit_t original, key_limit_t *new_key) { |
+ if (original == NULL) |
+ return err_status_bad_param; |
+ *new_key = original; |
+ return err_status_ok; |
+} |
+ |
+err_status_t |
+key_limit_check(const key_limit_t key) { |
+ if (key->state == key_state_expired) |
+ return err_status_key_expired; |
+ return err_status_ok; |
+} |
+ |
+key_event_t |
+key_limit_update(key_limit_t key) { |
+#ifdef NO_64BIT_MATH |
+ if (low32(key->num_left) == 0) |
+ { |
+ // carry |
+ key->num_left = make64(high32(key->num_left)-1,low32(key->num_left) - 1); |
+ } |
+ else |
+ { |
+ // no carry |
+ key->num_left = make64(high32(key->num_left),low32(key->num_left) - 1); |
+ } |
+ if (high32(key->num_left) != 0 || low32(key->num_left) >= soft_limit) { |
+ return key_event_normal; /* we're above the soft limit */ |
+ } |
+#else |
+ key->num_left--; |
+ if (key->num_left >= soft_limit) { |
+ return key_event_normal; /* we're above the soft limit */ |
+ } |
+#endif |
+ if (key->state == key_state_normal) { |
+ /* we just passed the soft limit, so change the state */ |
+ key->state = key_state_past_soft_limit; |
+ } |
+#ifdef NO_64BIT_MATH |
+ if (low32(key->num_left) == 0 && high32(key->num_left == 0)) |
+#else |
+ if (key->num_left < 1) |
+#endif |
+ { /* we just hit the hard limit */ |
+ key->state = key_state_expired; |
+ return key_event_hard_limit; |
+ } |
+ return key_event_soft_limit; |
+} |
+ |
Property changes on: libsrtp/crypto/kernel/key.c |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |