Alexandre Lision | 8af73cb | 2013-12-10 14:11:20 -0500 | [diff] [blame] | 1 | /* |
| 2 | * key.c |
| 3 | * |
| 4 | * key usage limits enforcement |
| 5 | * |
| 6 | * David A. Mcgrew |
| 7 | * Cisco Systems, Inc. |
| 8 | */ |
| 9 | /* |
| 10 | * |
| 11 | * Copyright (c) 2001-2006 Cisco Systems, Inc. |
| 12 | * All rights reserved. |
| 13 | * |
| 14 | * Redistribution and use in source and binary forms, with or without |
| 15 | * modification, are permitted provided that the following conditions |
| 16 | * are met: |
| 17 | * |
| 18 | * Redistributions of source code must retain the above copyright |
| 19 | * notice, this list of conditions and the following disclaimer. |
| 20 | * |
| 21 | * Redistributions in binary form must reproduce the above |
| 22 | * copyright notice, this list of conditions and the following |
| 23 | * disclaimer in the documentation and/or other materials provided |
| 24 | * with the distribution. |
| 25 | * |
| 26 | * Neither the name of the Cisco Systems, Inc. nor the names of its |
| 27 | * contributors may be used to endorse or promote products derived |
| 28 | * from this software without specific prior written permission. |
| 29 | * |
| 30 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 31 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 32 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 33 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 34 | * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, |
| 35 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 36 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| 37 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 40 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| 41 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
| 42 | * |
| 43 | */ |
| 44 | |
| 45 | #include "key.h" |
| 46 | |
| 47 | #define soft_limit 0x10000 |
| 48 | |
| 49 | err_status_t |
| 50 | key_limit_set(key_limit_t key, const xtd_seq_num_t s) { |
| 51 | #ifdef NO_64BIT_MATH |
| 52 | if (high32(s) == 0 && low32(s) < soft_limit) |
| 53 | return err_status_bad_param; |
| 54 | #else |
| 55 | if (s < soft_limit) |
| 56 | return err_status_bad_param; |
| 57 | #endif |
| 58 | key->num_left = s; |
| 59 | key->state = key_state_normal; |
| 60 | return err_status_ok; |
| 61 | } |
| 62 | |
| 63 | err_status_t |
| 64 | key_limit_clone(key_limit_t original, key_limit_t *new_key) { |
| 65 | if (original == NULL) |
| 66 | return err_status_bad_param; |
| 67 | *new_key = original; |
| 68 | return err_status_ok; |
| 69 | } |
| 70 | |
| 71 | err_status_t |
| 72 | key_limit_check(const key_limit_t key) { |
| 73 | if (key->state == key_state_expired) |
| 74 | return err_status_key_expired; |
| 75 | return err_status_ok; |
| 76 | } |
| 77 | |
| 78 | key_event_t |
| 79 | key_limit_update(key_limit_t key) { |
| 80 | #ifdef NO_64BIT_MATH |
| 81 | if (low32(key->num_left) == 0) |
| 82 | { |
| 83 | // carry |
| 84 | key->num_left = make64(high32(key->num_left)-1,low32(key->num_left) - 1); |
| 85 | } |
| 86 | else |
| 87 | { |
| 88 | // no carry |
| 89 | key->num_left = make64(high32(key->num_left),low32(key->num_left) - 1); |
| 90 | } |
| 91 | if (high32(key->num_left) != 0 || low32(key->num_left) >= soft_limit) { |
| 92 | return key_event_normal; /* we're above the soft limit */ |
| 93 | } |
| 94 | #else |
| 95 | key->num_left--; |
| 96 | if (key->num_left >= soft_limit) { |
| 97 | return key_event_normal; /* we're above the soft limit */ |
| 98 | } |
| 99 | #endif |
| 100 | if (key->state == key_state_normal) { |
| 101 | /* we just passed the soft limit, so change the state */ |
| 102 | key->state = key_state_past_soft_limit; |
| 103 | } |
| 104 | #ifdef NO_64BIT_MATH |
| 105 | if (low32(key->num_left) == 0 && high32(key->num_left == 0)) |
| 106 | #else |
| 107 | if (key->num_left < 1) |
| 108 | #endif |
| 109 | { /* we just hit the hard limit */ |
| 110 | key->state = key_state_expired; |
| 111 | return key_event_hard_limit; |
| 112 | } |
| 113 | return key_event_soft_limit; |
| 114 | } |
| 115 | |