PuTTY is copyright 1997-2001 Simon Tatham.
Portions copyright Robert de Bath, Joris van Rantwijk, Delian
-Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas Barry.
+Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas Barry,
+and CORE SDI S.A.
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation files
COBJS = console.$(OBJ)
##-- objects putty pscp psftp plink
OBJS1 = sshcrc.$(OBJ) sshdes.$(OBJ) sshmd5.$(OBJ) sshrsa.$(OBJ) sshrand.$(OBJ)
-OBJS2 = sshsha.$(OBJ) sshblowf.$(OBJ) noise.$(OBJ) sshdh.$(OBJ) sshdss.$(OBJ)
-OBJS3 = sshbn.$(OBJ) sshpubk.$(OBJ) ssh.$(OBJ) pageantc.$(OBJ) sshzlib.$(OBJ)
-OBJS4 = x11fwd.$(OBJ) portfwd.$(OBJ) sshaes.$(OBJ) sshsh512.$(OBJ)
+OBJS2 = sshsha.$(OBJ) sshblowf.$(OBJ) noise.$(OBJ) sshdh.$(OBJ) sshcrcda.$(OBJ)
+OBJS3 = sshpubk.$(OBJ) ssh.$(OBJ) pageantc.$(OBJ) sshzlib.$(OBJ) sshdss.$(OBJ)
+OBJS4 = x11fwd.$(OBJ) portfwd.$(OBJ) sshaes.$(OBJ) sshsh512.$(OBJ) sshbn.$(OBJ)
##-- objects pageant
PAGE1 = pageant.$(OBJ) sshrsa.$(OBJ) sshpubk.$(OBJ) sshdes.$(OBJ) sshbn.$(OBJ)
PAGE2 = sshmd5.$(OBJ) version.$(OBJ) tree234.$(OBJ) misc.$(OBJ) sshaes.$(OBJ)
-\versionid $Id: licence.but,v 1.1 2001/12/16 14:56:02 simon Exp $
+\versionid $Id: licence.but,v 1.2 2002/01/08 11:57:32 simon Exp $
\A{licence} PuTTY Licence
PuTTY is copyright 1997-2001 Simon Tatham.
Portions copyright Robert de Bath, Joris van Rantwijk, Delian
-Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas Barry.
+Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas Barry,
+and CORE SDI S.A.
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation files
LTEXT "Portions copyright Robert de Bath, Joris van Rantwijk, Delian", 1001, 10, 26, 206, 8
LTEXT "Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas", 1002, 10, 34, 206, 8
- LTEXT "Barry.", 1003, 10, 42, 206, 8
+ LTEXT "Barry, and CORE SDI S.A.", 1003, 10, 42, 206, 8
LTEXT "Permission is hereby granted, free of charge, to any person", 1004, 10, 58, 206, 8
LTEXT "obtaining a copy of this software and associated documentation", 1005, 10, 66, 206, 8
LTEXT "Portions copyright Robert de Bath, Joris van Rantwijk, Delian", 1001, 10, 26, 206, 8
LTEXT "Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas", 1002, 10, 34, 206, 8
- LTEXT "Barry.", 1003, 10, 42, 206, 8
+ LTEXT "Barry, and CORE SDI S.A.", 1003, 10, 42, 206, 8
LTEXT "Permission is hereby granted, free of charge, to any person", 1004, 10, 58, 206, 8
LTEXT "obtaining a copy of this software and associated documentation", 1005, 10, 66, 206, 8
st->to_read -= st->chunk;
}
+ if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
+ bombout(("Network attack (CRC compensation) detected!"));
+ crReturn(0);
+ }
+
if (cipher)
cipher->decrypt(pktin.data, st->biglen);
typedef unsigned int uint32;
unsigned long crc32(const void *s, size_t len);
+unsigned long crc32_update(unsigned long crc_input, const void *s, size_t len);
+
+/* SSH CRC compensation attack detector */
+int detect_attack(unsigned char *buf, uint32 len, unsigned char *IV);
typedef struct {
uint32 h[4];
}
#endif
-unsigned long crc32(const void *buf, size_t len)
+unsigned long crc32_update(unsigned long crcword, const void *buf, size_t len)
{
- unsigned long crcword = 0L;
const unsigned char *p = (const unsigned char *) buf;
while (len--) {
unsigned long newbyte = *p++;
}
return crcword;
}
+
+unsigned long crc32(const void *buf, size_t len)
+{
+ return crc32_update(0L, buf, len);
+}
--- /dev/null
+/* $OpenBSD: deattack.c,v 1.14 2001/06/23 15:12:18 itojun Exp $ */
+
+/*
+ * 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>
+ *
+ * Modified for use in PuTTY by Simon Tatham
+ */
+
+#include <assert.h>
+#include "misc.h"
+#include "ssh.h"
+
+typedef unsigned char uchar;
+typedef unsigned short uint16;
+
+/* SSH Constants */
+#define SSH_MAXBLOCKS (32 * 1024)
+#define SSH_BLOCKSIZE (8)
+
+/* Hashing constants */
+#define HASH_MINSIZE (8 * 1024)
+#define HASH_ENTRYSIZE (sizeof(uint16))
+#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)
+
+#define GET_32BIT_MSB_FIRST(cp) \
+ (((unsigned long)(unsigned char)(cp)[0] << 24) | \
+ ((unsigned long)(unsigned char)(cp)[1] << 16) | \
+ ((unsigned long)(unsigned char)(cp)[2] << 8) | \
+ ((unsigned long)(unsigned char)(cp)[3]))
+
+/* Hash function (Input keys are cipher results) */
+#define HASH(x) GET_32BIT_MSB_FIRST(x)
+
+#define CMP(a, b) (memcmp(a, b, SSH_BLOCKSIZE))
+
+uchar ONE[4] = { 1, 0, 0, 0 };
+uchar ZERO[4] = { 0, 0, 0, 0 };
+
+static void crc_update(uint32 *a, void *b)
+{
+ *a = crc32_update(*a, b, 4);
+}
+
+/* detect if a block is used in a particular pattern */
+static int check_crc(uchar *S, uchar *buf, uint32 len, uchar *IV)
+{
+ uint32 crc;
+ uchar *c;
+
+ crc = 0;
+ if (IV && !CMP(S, IV)) {
+ crc_update(&crc, ONE);
+ crc_update(&crc, ZERO);
+ }
+ for (c = buf; c < buf + len; c += SSH_BLOCKSIZE) {
+ if (!CMP(S, c)) {
+ crc_update(&crc, ONE);
+ crc_update(&crc, ZERO);
+ } else {
+ crc_update(&crc, ZERO);
+ crc_update(&crc, ZERO);
+ }
+ }
+ return (crc == 0);
+}
+
+/* Detect a crc32 compensation attack on a packet */
+int detect_attack(uchar *buf, uint32 len, uchar *IV)
+{
+ static uint16 *h = (uint16 *) NULL;
+ static uint32 n = HASH_MINSIZE / HASH_ENTRYSIZE;
+ register uint32 i, j;
+ uint32 l;
+ register uchar *c;
+ uchar *d;
+
+ assert(!(len > (SSH_MAXBLOCKS * SSH_BLOCKSIZE) ||
+ len % SSH_BLOCKSIZE != 0));
+ for (l = n; l < HASH_FACTOR(len / SSH_BLOCKSIZE); l = l << 2)
+ ;
+
+ if (h == NULL) {
+ logevent("Installing CRC compensation attack detector");
+ n = l;
+ h = (uint16 *) smalloc(n * HASH_ENTRYSIZE);
+ } else {
+ if (l > n) {
+ n = l;
+ h = (uint16 *) srealloc(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 1; /* attack detected */
+ else
+ break;
+ }
+ for (d = buf; d < c; d += SSH_BLOCKSIZE) {
+ if (!CMP(c, d)) {
+ if ((check_crc(c, buf, len, IV)))
+ return 1; /* attack detected */
+ else
+ break;
+ }
+ }
+ }
+ return 0; /* ok */
+ }
+ memset(h, HASH_UNUSEDCHAR, n * HASH_ENTRYSIZE);
+
+ if (IV)
+ h[HASH(IV) & (n - 1)] = HASH_IV;
+
+ for (c = buf, 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 1; /* attack detected */
+ else
+ break;
+ }
+ } else if (!CMP(c, buf + h[i] * SSH_BLOCKSIZE)) {
+ if (check_crc(c, buf, len, IV))
+ return 1; /* attack detected */
+ else
+ break;
+ }
+ }
+ h[i] = j;
+ }
+ return 0; /* ok */
+}
LTEXT "Portions copyright Robert de Bath, Joris van Rantwijk, Delian", 1001, 10, 26, 206, 8
LTEXT "Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas", 1002, 10, 34, 206, 8
- LTEXT "Barry.", 1003, 10, 42, 206, 8
+ LTEXT "Barry, and CORE SDI S.A.", 1003, 10, 42, 206, 8
LTEXT "Permission is hereby granted, free of charge, to any person", 1004, 10, 58, 206, 8
LTEXT "obtaining a copy of this software and associated documentation", 1005, 10, 66, 206, 8