| ip_id.c (126263) | ip_id.c (133720) |
|---|---|
| 1/* $OpenBSD: ip_id.c,v 1.2 1999/08/26 13:37:01 provos Exp $ */ 2 3/* 4 * Copyright 1998 Niels Provos <provos@citi.umich.edu> 5 * All rights reserved. 6 * 7 * Theo de Raadt <deraadt@openbsd.org> came up with the idea of using 8 * such a mathematical system to generate more random (yet non-repeating) --- 20 unchanged lines hidden (view full) --- 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * | 1/* $OpenBSD: ip_id.c,v 1.2 1999/08/26 13:37:01 provos Exp $ */ 2 3/* 4 * Copyright 1998 Niels Provos <provos@citi.umich.edu> 5 * All rights reserved. 6 * 7 * Theo de Raadt <deraadt@openbsd.org> came up with the idea of using 8 * such a mathematical system to generate more random (yet non-repeating) --- 20 unchanged lines hidden (view full) --- 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * |
| 37 * $FreeBSD: head/sys/netinet/ip_id.c 126263 2004-02-26 03:53:54Z mlaier $ | 37 * $FreeBSD: head/sys/netinet/ip_id.c 133720 2004-08-14 15:32:40Z dwmalone $ |
| 38 */ 39 40/* 41 * seed = random 15bit 42 * n = prime, g0 = generator to n, 43 * j = random so that gcd(j,n-1) == 1 44 * g = g0^j mod n will be a generator again. 45 * --- 6 unchanged lines hidden (view full) --- 52 * The transaction id is determined by: 53 * id[n] = seed xor (g^X[n] mod n) 54 * 55 * Effectivly the id is restricted to the lower 15 bits, thus 56 * yielding two different cycles by toggling the msb on and off. 57 * This avoids reuse issues caused by reseeding. 58 */ 59 | 38 */ 39 40/* 41 * seed = random 15bit 42 * n = prime, g0 = generator to n, 43 * j = random so that gcd(j,n-1) == 1 44 * g = g0^j mod n will be a generator again. 45 * --- 6 unchanged lines hidden (view full) --- 52 * The transaction id is determined by: 53 * id[n] = seed xor (g^X[n] mod n) 54 * 55 * Effectivly the id is restricted to the lower 15 bits, thus 56 * yielding two different cycles by toggling the msb on and off. 57 * This avoids reuse issues caused by reseeding. 58 */ 59 |
| 60#include "opt_random_ip_id.h" | |
| 61#include "opt_pf.h" 62#include <sys/param.h> 63#include <sys/time.h> 64#include <sys/kernel.h> 65#include <sys/random.h> 66 | 60#include "opt_pf.h" 61#include <sys/param.h> 62#include <sys/time.h> 63#include <sys/kernel.h> 64#include <sys/random.h> 65 |
| 67#if defined(RANDOM_IP_ID) || defined(DEV_PF) | |
| 68#define RU_OUT 180 /* Time after wich will be reseeded */ 69#define RU_MAX 30000 /* Uniq cycle, avoid blackjack prediction */ 70#define RU_GEN 2 /* Starting generator */ 71#define RU_N 32749 /* RU_N-1 = 2*2*3*2729 */ 72#define RU_AGEN 7 /* determine ru_a as RU_AGEN^(2*rand) */ 73#define RU_M 31104 /* RU_M = 2^7*3^5 - don't change */ 74 75#define PFAC_N 3 --- 128 unchanged lines hidden (view full) --- 204 /* Linear Congruential Generator */ 205 ru_x = (ru_a*ru_x + ru_b) % RU_M; 206 207 ru_counter += i; 208 209 return (ru_seed ^ pmod(ru_g,ru_seed2 ^ ru_x,RU_N)) | ru_msb; 210} 211 | 66#define RU_OUT 180 /* Time after wich will be reseeded */ 67#define RU_MAX 30000 /* Uniq cycle, avoid blackjack prediction */ 68#define RU_GEN 2 /* Starting generator */ 69#define RU_N 32749 /* RU_N-1 = 2*2*3*2729 */ 70#define RU_AGEN 7 /* determine ru_a as RU_AGEN^(2*rand) */ 71#define RU_M 31104 /* RU_M = 2^7*3^5 - don't change */ 72 73#define PFAC_N 3 --- 128 unchanged lines hidden (view full) --- 202 /* Linear Congruential Generator */ 203 ru_x = (ru_a*ru_x + ru_b) % RU_M; 204 205 ru_counter += i; 206 207 return (ru_seed ^ pmod(ru_g,ru_seed2 ^ ru_x,RU_N)) | ru_msb; 208} 209 |
| 212#endif /* RANDOM_IP_ID || DEV_PF */ | |