Ike-scan Recent Changes

This page contains details of the recent changes in ike-scan. The data comes from the NEWS file, which is included in the ike-scan source code release.

For details of proposed features for future releases, see Desired New Features.

New Features in ike-scan v1.9, Released January 2007

• ike-scan wiki at http://www.nta-monitor.com/wiki/. This will contain ike-scan documentation and associated IPsec information.

• IKEv2 support with --ikev2 option that sends IKE version 2 format packets, and version 2 packets that are received are correctly decoded. The IKEv2 support is currently experimental as it has only been tested against one implementation (strongSwan), and it only supports the default proposal.

• New --rcookie option allows the responder cookie to be set to the specified value in outgoing packets. The default is zero.

• psk-crack allows the dictionary to be read from stdin with the --dictionary=- option. This allows another program to generate candidate passwords, e.g. john --incremental --stdout | psk-crack --dictionary=- psk-file

• New --nat-t option to enable RFC 3947 NAT Traversal. This option adds the Non-ESP marker to outbound packets and strips it from responses. It also changes the default UDP source and destination ports both to 4500.

• New --sourceip option, which allows spoofing source IP address. This only works on systems that support raw sockets.

• Allow matching backoff patterns which contain only one packet. This is for simplistic implementations that don't perform any backoff at all. There are very few of these systems, so this absense of a pattern is still useful for fingerprinting.

• psk-crack is able to crack passwords hased with the Nortel Contivity proprietary algorithm as well as those using the standard algorithm.

• New --shownum option, which causes the number of each packet received to be displayed before the packet details.

• New --timestamp option, which causes the time when the packet was received to be displayed in %H:%M:%S.%u format before the packet details.

• New --randomseed option, which allows the PRNG seed to be specified. This allows packets containing payloads with random data, such as Key Exchange and Nonce to be repeatable.

• Changed PRNG implementation from the standard rand() function to the Mersenne Twister. This is both a better PRNG and is also reproducable across different platforms.

• Changed revision control system from CVS to SVN, with the result that the individual source file version numbers as reported with --version or ident(1) are now integers like 9876 rather than 1.x format.

• Improved "make check" tests to check new features and increase code coverage.

New Features in ike-scan v1.8, Released December 2005

• Added many new vendor ID and UDP backoff patterns. There are now a total of 29 backoff patterns, and 135 vendor ID patterns.

• Several bugs fixed in both psk-crack and ike-scan. Notable fixes include:
  • Numeric arguments are now checked for validity
  • Perform 64-bit time calculations correctly
  • Correct psk-crack handling of multiple PSK records
  • Fixed bug which caused hostnames containing hyphens to fail with an error.
  • Name lookup errors are now non-fatal.

• Added support for more flexible transform specification, which allows an arbitary number of transform attributes to be specified in any order. This new method is specified by using an alternative syntax for the --trans option: --trans=(attr=value, ...). The old syntax of --trans=a,b,c,d is still available. Note that the brackets are special to some shells, and may need to be quoted.

• Made the specification of the lifetime and lifesize transform attributes with the --lifetime and --lifesize options more flexible. Now, the argument to these options can take three different forms:
  • The string "none" - Do not add any lifetime or lifesize attribute.
  • A decimal integer, e.g. 86400 - Add a 4-byte value.
  • A hex number, e.g. 0xff - Add a variable length value. The hex notation allows arbitary length lifetime and lifesize attributes to be added

• Changed default packet-rate calculation from interval to bandwidth. The default outgoing bandwidth is 56000 bits per second, and can be changed with the --bandwidth option. It is still possible to specify an inter-packet interval instead with the --interval option.

• Display the version, flags and msgid from the ISAKMP header if they don't contain the expected value.

• Decode and display CERTIFICATE, DELETE and NOTIFICATION payloads if they are received.

• Display the responder cookie from the ISAKMP header unless quiet is in effect.

• Display the SPI if its size is non-zero. Normally, the SPI size is zero during Phase-1, but I've observed some implementations to use a non-zero length, which is permitted by RFC 2408.

• Added new options to allow more control of the outgoing packet. Note that some of these options can make the outgoing packet non RFC compliant:
  • --spisize Adds a random SPI of the specified length to the proposal payload
  • --cookie Sets the initiatior cookie to the specified static value
  • --hdrflags Sets the flags field in the ISAKMP header
  • --hdrmsgid Sets the MsgID field in the ISAKMP header
  • --exchange sets the exchange field in the ISAKMP header to the specified value
  • --noncelen (-c) allows the length of the nonce data to be specified
  • --bandwidth (-B) specify desired outgoing bandwidth usage
  • --certreq (-C) Adds a CertificateRequest payload to the outgoing packet
  • --headerlen (-L) allows the ISAKMP header length to be manually specified
  • --mbz (-Z) allows the value for the reserved fields that "must be zero" to be sent to a specified non-zero value
  • --headerver (-E) allows the header version in the ISAKMP header to be changed from the default of 0x10 (v1.0)
  • --protocol (-j) allows the proposal protocol to be changed from the default
  • --transid (-k) allows the transform id to be changed from the default
  • --doi (-D) allows the DOI in the SA to be changed from the default
  • --situation (-S) allows the Situation in the SA to be changed from the default

• The full help output is now only displayed if it is specifically requested by running ike-scan with the --help (-h) option. Usage errors now result in a smaller help output. This avoids outputting a multi-screen usage message just because of a typo on the command line.

• drop root privilege after binding the local port if we are running SUID. This improves security somewhat.

• Make POSIX regular expression support mandatory. Previously, it was optional, but I'm not aware of any supported systems that lack it, and we are using it in more and more places.

• Improved mapping of ID numbers to names in decode. This allows sparse IDs ranges (e.g. 1,2,3,65000) to be supported, which means that we can now decode XAUTH authentication method amongst other things.

• Added SO_BROADCAST option to UDP socket to allow sending to broadcast addresses. Previously this gave a permission denied error, even for root.

• Added OpenSSL exception to the copyright notice, which permits linking of the program against OpenSSL. This is to allow the use of OpenSSL in this GPL v2 licensed program.

New Features in ike-scan v1.7, Released January 2005

• Improved "make check" tests, so they now check more areas including Pre-Shared Key cracking, HMAC and Hash speeds, and HMAC and Hash test vectors.

• Added --nodns (-N) option to prevent DNS lookups. With this option, target hosts are not processed with gethostbyname(), which can avoid delays when the system running ike-scan does not have functioning DNS.

• Added additional authentication methods and hash algorithms to the output decoding functions in isakmp.c

• Added new psk-crack program to perform offline aggressive mode pre-shared key cracking using the output from ike-scan with the --pskcrack option. This psk-crack program supports both dictionary and brute-force cracking modes against MD5 and SHA1-based HMAC hashes.

• Added ability to output aggressive mode pre-shared key (PSK) parameters for later offline cracking with the --pskcrack (-P) option. This option outputs the pre-shared key parameters as colon-separated hex-encoded values in the following format:

  g_xr:g_xi:cky_r:cky_i:sai_b:idir_b:ni_b:nr_b:hash_r

  These parameter details can be used by the psk-crack program (which is supplied as part of the ike-scan package) to attempt to crack the pre-shared key.

• Added support for IKE over TCP with the --tcp (-T) option. Two TCP variants are supported:
  • --tcp=1 (-T1) specifies raw IKE over TCP as used by Checkpoint; and
  • --tcp=2 (-T2) specifies encapsulated IKE over TCP as used by Cisco.

  You can only scan one host at a time when using IKE over TCP.

  When using TCP, you can modify the connect() timeout with the --tcptimeout (-O) option. Default timeout is 10 seconds.

• Added experimental timing error smoothing code, which is based on the TCP RTT smoothing algorithm in RFC 793. This is disabled by default; to enable it, #define ALPHA in ike-scan.h

• Allow the ID (Identity) payload that is specified with the --id option to be specified as either a string e.g. --id=test or a hex value with a leading 0x e.g. --id=0xdeadbeef. Note that you will probably need to change previous ID payload strings because of this change, as previously they were always interpreted as hex.

• Added support for OpenSSL MD5 and SHA1 hash functions. These are generally faster than the hash functions supplied with ike-scan, which is of benefit when performing pre-shared key cracking. To compile with OpenSSL, use the --with-openssl option to configure. With this option, configure will search for the OpenSSL libraries in several standard locations.

• Added --random (-R) option to randomise the host list before scanning. This causes the hosts to be scanned in a random order, which may be less obvious than the default sequential scanning. The Knuth shuffle algorithm is used to randomise the list.

• Changed host entry from a linked-list to a dynamic array which decreases the memory required from 56 bytes per target host to 45 bytes.

• Added several new Vendor ID patterns.

• Added several new UDP backoff patterns.

New Features in ike-scan v1.6, Released January 2004

• ike-scan will now display multiple Vendor ID payloads if the server sends more than one. Previously, it would only display the first Vendor ID and ignore the others.

• Added support for ISAKMP lifetime size transform attribute with the --lifesize (-z) option. This is specified as kilobytes. The default is 0 which means don't include the lifetime size attribute.

• Added support for GSS IDs with --gssid (-G) option. GSS IDs are described in draft-ietf-ipsec-isakmp-gss-auth-07.txt. This is used by Windows-2000 IPsec for Kerberos authentication.

• Allow target hosts to be specified as IPnet/bits to include all hosts in the given network, or IPstart-IPend to include all hosts in the inclusive range as well as single hostnames or IP addresses.

• Added support for Vendor ID fingerprinting. The file "ike-vendor-ids" contains a list of known Vendor ID patterns, specified as Posix extended regular expressions. These are used to match against the ascii hex representation of any returned Vendor IDs, and the name of the entry is displayed if a match is found.

• SA transform attributes and ID payloads are now decoded, and basic details (name and size) are displayed for payload types that we don't decode yet.
  • Added --quiet option to prevent this decoding if it's not required.
  • Added --multiline option to split the decode over multiple lines - one line per payload. With --multiline, each payload decode line starts with a TAB.

New Features in ike-scan v1.5.1, Released November 2003

This was a bugfix release to fix the following issue:

• Fixed a bug which could cause a negative value to be passed to select() when collecting backoff fingerprints. This would result in select() returning EINVAL.

New Features in ike-scan v1.5, Released November 2003

• Aggressive mode is now supported. The --aggressive (-A) option specifies aggressive mode.

• The --trans option can be specified multiple times to generate an arbitrary number of custom transforms in the ISAKMP SA Proposal.

• The --vendor option can be specified multiple times to generate an arbitrary number of Vendor ID payloads.

• UDP engine improvements: Dynamically adjust select() timeout, removing the need for a --selectwait argument; keep track of cumulative timing error, and use this to adjust the timing to compensate; calculate timings in microseconds rather than milliseconds to improve accuracy; and some minor tuning.

New Features in ike-scan v1.4, Released August 2003

• Two additions to permit Vendor ID fingerprinting.
  • Allow the specification of an arbitrary Vendor ID payload using the --vendor option.
  • Display any Vendor ID payload returned by the target host.

New Features in ike-scan v1.3, Released July 2003 (Unofficial release)

This was an unofficial release, and no Windows zipfile was produced.

• Added support for per-pattern-entry fuzz values in the backoff patterns file which allows more complex backoff patterns to be matched.

• Added new backoff patterns for "watchguard-soho" and "sonicwall-pro".

New Features in ike-scan v1.2, Released June 2003

• Fixed format string vulnerability in syslog() call.
• ike-scan now builds and runs on HP Tru64 Unix.

New Features in ike-scan v1.1, Released February 2003

• Added new backoff patterns for Cisco Concentrator and isakmpd.
• ike-scan now builds and runs on Windows/Cygwin, old libc5 Linux systems, and Solaris 2.8 / SPARC.
• Windows command-line binary released.

ike-scan v1.0, Released January 2003 (Initial release)

• Compiles and runs on Debian Linux 2.2 "potato" and 3.0 "woody", FreeBSD 4.3, and OpenBSD 3.1.