summaryrefslogtreecommitdiff
path: root/usr/src/cmd/ssh/libssh/common/deattack.c
diff options
context:
space:
mode:
authorAlex Wilson <alex.wilson@joyent.com>2015-08-11 00:23:16 +0000
committerAlex Wilson <alex.wilson@joyent.com>2015-09-03 14:05:34 -0700
commitd0c1b872bd54d7989a1f97af5d5d86ec4a13cabe (patch)
tree76af59311a3eb0011f3012489d059212ea21cd21 /usr/src/cmd/ssh/libssh/common/deattack.c
parent42d2cb6faf809f84bbfd0fd73fe6f644b8417053 (diff)
downloadillumos-joyent-d0c1b872bd54d7989a1f97af5d5d86ec4a13cabe.tar.gz
OS-4689 Remove SunSSH from illumos-joyent
OS-4688 Switch platform over to using recent OpenSSH Reviewed by: Robert Mustacchi <rm@joyent.com>
Diffstat (limited to 'usr/src/cmd/ssh/libssh/common/deattack.c')
-rw-r--r--usr/src/cmd/ssh/libssh/common/deattack.c178
1 files changed, 0 insertions, 178 deletions
diff --git a/usr/src/cmd/ssh/libssh/common/deattack.c b/usr/src/cmd/ssh/libssh/common/deattack.c
deleted file mode 100644
index 82afd4f16b..0000000000
--- a/usr/src/cmd/ssh/libssh/common/deattack.c
+++ /dev/null
@@ -1,178 +0,0 @@
-/*
- * Cryptographic attack detector for ssh - source code
- *
- * Copyright (c) 1998 CORE SDI S.A., Buenos Aires, Argentina.
- *
- * All rights reserved. Redistribution and use in source and binary
- * forms, with or without modification, are permitted provided that
- * this copyright notice is retained.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES ARE DISCLAIMED. IN NO EVENT SHALL CORE SDI S.A. BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY OR
- * CONSEQUENTIAL DAMAGES RESULTING FROM THE USE OR MISUSE OF THIS
- * SOFTWARE.
- *
- * Ariel Futoransky <futo@core-sdi.com>
- * <http://www.core-sdi.com>
- */
-
-#include "includes.h"
-RCSID("$OpenBSD: deattack.c,v 1.18 2002/03/04 17:27:39 stevesk Exp $");
-
-#pragma ident "%Z%%M% %I% %E% SMI"
-
-#include "deattack.h"
-#include "log.h"
-#include "crc32.h"
-#include "getput.h"
-#include "xmalloc.h"
-#include "deattack.h"
-
-/*
- * CRC attack detection has a worst-case behaviour that is O(N^2) over
- * the number of identical blocks in a packet. This behaviour can be
- * exploited to create a limited denial of service attack.
- *
- * However, because we are dealing with encrypted data, identical
- * blocks should only occur every 2^35 maximally-sized packets or so.
- * Consequently, we can detect this DoS by looking for identical blocks
- * in a packet.
- *
- * The parameter below determines how many identical blocks we will
- * accept in a single packet, trading off between attack detection and
- * likelihood of terminating a legitimate connection. A value of 32
- * corresponds to an average of 2^40 messages before an attack is
- * misdetected
- */
-#define MAX_IDENTICAL 32
-
-/* SSH Constants */
-#define SSH_MAXBLOCKS (32 * 1024)
-#define SSH_BLOCKSIZE (8)
-
-/* Hashing constants */
-#define HASH_MINSIZE (8 * 1024)
-#define HASH_ENTRYSIZE (2)
-#define HASH_FACTOR(x) ((x)*3/2)
-#define HASH_UNUSEDCHAR (0xff)
-#define HASH_UNUSED (0xffff)
-#define HASH_IV (0xfffe)
-
-#define HASH_MINBLOCKS (7*SSH_BLOCKSIZE)
-
-
-/* Hash function (Input keys are cipher results) */
-#define HASH(x) GET_32BIT(x)
-
-#define CMP(a, b) (memcmp(a, b, SSH_BLOCKSIZE))
-
-static void
-crc_update(u_int32_t *a, u_int32_t b)
-{
- b ^= *a;
- *a = ssh_crc32((u_char *) &b, sizeof(b));
-}
-
-/* detect if a block is used in a particular pattern */
-static int
-check_crc(u_char *S, u_char *buf, u_int32_t len,
- u_char *IV)
-{
- u_int32_t crc;
- u_char *c;
-
- crc = 0;
- if (IV && !CMP(S, IV)) {
- crc_update(&crc, 1);
- crc_update(&crc, 0);
- }
- for (c = buf; c < buf + len; c += SSH_BLOCKSIZE) {
- if (!CMP(S, c)) {
- crc_update(&crc, 1);
- crc_update(&crc, 0);
- } else {
- crc_update(&crc, 0);
- crc_update(&crc, 0);
- }
- }
- return (crc == 0);
-}
-
-
-/* Detect a crc32 compensation attack on a packet */
-int
-detect_attack(u_char *buf, u_int32_t len, u_char *IV)
-{
- static u_int16_t *h = (u_int16_t *) NULL;
- static u_int32_t n = HASH_MINSIZE / HASH_ENTRYSIZE;
- u_int32_t i, j;
- u_int32_t l, same;
- u_char *c;
- u_char *d;
-
- if (len > (SSH_MAXBLOCKS * SSH_BLOCKSIZE) ||
- len % SSH_BLOCKSIZE != 0) {
- fatal("detect_attack: bad length %d", len);
- }
- for (l = n; l < HASH_FACTOR(len / SSH_BLOCKSIZE); l = l << 2)
- ;
-
- if (h == NULL) {
- debug("Installing crc compensation attack detector.");
- n = l;
- h = (u_int16_t *) xmalloc(n * HASH_ENTRYSIZE);
- } else {
- if (l > n) {
- n = l;
- h = (u_int16_t *) xrealloc(h, n * HASH_ENTRYSIZE);
- }
- }
-
- if (len <= HASH_MINBLOCKS) {
- for (c = buf; c < buf + len; c += SSH_BLOCKSIZE) {
- if (IV && (!CMP(c, IV))) {
- if ((check_crc(c, buf, len, IV)))
- return (DEATTACK_DETECTED);
- else
- break;
- }
- for (d = buf; d < c; d += SSH_BLOCKSIZE) {
- if (!CMP(c, d)) {
- if ((check_crc(c, buf, len, IV)))
- return (DEATTACK_DETECTED);
- else
- break;
- }
- }
- }
- return (DEATTACK_OK);
- }
- memset(h, HASH_UNUSEDCHAR, n * HASH_ENTRYSIZE);
-
- if (IV)
- h[HASH(IV) & (n - 1)] = HASH_IV;
-
- for (c = buf, same = j = 0; c < (buf + len); c += SSH_BLOCKSIZE, j++) {
- for (i = HASH(c) & (n - 1); h[i] != HASH_UNUSED;
- i = (i + 1) & (n - 1)) {
- if (h[i] == HASH_IV) {
- if (!CMP(c, IV)) {
- if (check_crc(c, buf, len, IV))
- return (DEATTACK_DETECTED);
- else
- break;
- }
- } else if (!CMP(c, buf + h[i] * SSH_BLOCKSIZE)) {
- if (++same > MAX_IDENTICAL)
- return (DEATTACK_DOS_DETECTED);
- if (check_crc(c, buf, len, IV))
- return (DEATTACK_DETECTED);
- else
- break;
- }
- }
- h[i] = j;
- }
- return (DEATTACK_OK);
-}