johndoe31415/ratchedRatched ist ein transparenter Man-in-the-Middle-TLS-Proxy, der für Penetrationstests vorgesehen ist.
ratched ist ein Man-in-the-Middle (MitM)-Proxy, der speziell TLS-Verbindungen abfängt. Es ist dafür gedacht, in Verbindung mit dem Linux iptables REDIRECT-Ziel verwendet zu werden; alle Verbindungen, die abgefangen werden sollen, können an den lokalen ratched-Port umgeleitet werden. Über den SO_ORIGINAL_DST sockopt kann ratched das ursprüngliche Ziel (vor der iptables-Paketmanipulation) ermitteln und versucht, eine Verbindung zum Originalziel aufzubauen.
Was es von anderer MitM-Software unterscheidet, ist Folgendes:
ratched fängt Datenverkehr nicht wahllos ab. Insbesondere wartet es zunächst darauf, dass der TLS-Client sein ClientHello sendet, damit ratched es parsen und anhand der Server Name Indication TLS-Erweiterung (SNI) entscheiden kann, ob das Ziel abgefangen werden soll oder nicht. Dies ist besonders nützlich, wenn Sie virtuelles Hosting haben, aber nur Verbindungen zu einem bestimmten Hostnamen abfangen möchten.
ratched ist nicht nur dazu gedacht, Passwörter zu schnüffeln, sondern exportiert den Datenverkehr hauptsächlich in eine PCAPNG-Datei. Das PCAPNG-Dateiformat wurde gewählt, weil es die Annotation von Verbindungen mit Kommentaren ermöglicht (insbesondere, welcher Hostname in der SNI-Erweiterung angegeben wurde) und auch die Einbettung von Namensauflösungsinformationen in die Capturedatei erlaubt (wiederum, um die Ziel-IP-Adresse dem Hostnamen der SNI-Erweiterung zuzuordnen).
ratched hat eine individuelle Konfiguration für jedes abgefangene SNI, einschließlich unterstützter Gruppen (früher bekannt als „unterstützte elliptische Kurven“), Cipher Suites und spezifischer TLS-Versionen auf Client- und Server-Seite, und erlaubt die Angabe benutzerdefinierter Zertifikate/Schlüssel für verschiedene abgefangene Hosts.
ratched bietet umfangreiche Unterstützung für Client-Zertifikate und ermöglicht auch das automatische Fälschen von Client-Zertifikaten (ähnlich wie gefälschte Server-Zertifikate in der anderen Richtung).
ratched unterstützt OCSP-Stapling und kann automatisch positive OCSP-Antworten fälschen, wenn ein Client eine Statusanfrage-TLS-Erweiterung sendet.
Sobald ratched auf dem Routing-Rechner lauscht (im Beispiel auf Port 9999), fügen Sie einfach einen iptables-Eintrag hinzu, der angibt, welchen Datenverkehr Sie erfassen möchten. Um zum Beispiel alles von 192.168.1.7 abzufangen, das Port 443 erreichen möchte, verwenden Sie:
# iptables -t nat -A PREROUTING -p tcp -s 192.168.1.7 --dport 443 -j REDIRECT --to-ports 9999
Um alles abzufangen, das an Port 443 geht, einfach:
# iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-ports 9999
Wenn Sie als Router fungieren und lokal eingehenden Datenverkehr abfangen möchten, verwenden Sie das DNAT-Ziel anstelle von REDIRECT, z. B.:
# iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 443 -j DNAT --to 192.168.123.1:9999
Hier ist eth1 die Schnittstelle, an der Sie den Datenverkehr abfangen, und 192.168.123.1 ist die lokale Schnittstellen-IP-Adresse.
Die Hilfeseite sollte weitgehend selbsterklärend sein:
usage: ratched [-c path] [-f hostname:port] [--single-shot] [--dump-certs]
[--keyspec keyspec] [--initial-read-timeout secs]
[--mark-forged-certificates] [--no-recalculate-keyids]
[--daemonize] [--logfile file] [--flush-logs] [--crl-uri uri]
[--ocsp-uri uri] [--write-memdumps-into-files]
[--use-ipv6-encapsulation] [-l hostname:port]
[-d key=value[,key=value,...]] [-i hostname[,key=value,...]]
[--pcap-comment comment] [-o filename] [-v]
ratched - TLS connection router that performs a man-in-the-middle attack
optional arguments:
-c path, --config-dir path
Configuration directory where the default root CA
certificate, CA keypair and server keypair are stored.
Defaults to ~/.config/ratched
-f hostname:port, --local-fwd hostname:port
When local connection to listening port is made, the
connection is discarded by default. Specifying this
option makes ratched forward to the given
hostname/port combination instead. Useful for testing
the proxy without the iptables REDIRECT.
--single-shot Only handle a single connection and terminate directly
after. Useful for debugging purposes.
--dump-certs Print created certificates for each intercepted
connection in the log file. Note that in many cases
you will also need to increase the log level to at
least DEBUG in order to see certificates.
--keyspec keyspec Specification for the private keys that should be
used. Can be either in the form "rsa:bitlen" or
"ecc:curvename". Valid choices, therefore, would be,
for example, "rsa:1024" or "ecc:secp256r1". Defaults
to rsa:2048
--initial-read-timeout secs
Specifies the amount of time in seconds (as a floating
point number) that ratched waits for the client to
provide its ClientHello before giving up. The default
is 1.0 secs.
--mark-forged-certificates
Include an OU=ratched entry to the subjects of all
created certificates (including dynamically forged
client certificates) for easy debugging.
--no-recalculate-keyids
When forging client certificates, by default the
subject and authority key identifiers are removed and
recreated to fit the actually used key ids. With this
option, they're used as-is (i.e., the key identifier
metadata will not fit the actually used keys). This
option might expose bugs in certain frameworks which
regard these identifiers as trusted information.
--daemonize Do not run in foreground mode, but in the background
as a daemon.
--logfile file Instead of logging to stderr, redirect logs to given
file.
--flush-logs Flush logfile after each call to logmsg(). Decreases
performance, but gives line-buffered logs.
--crl-uri uri Encode the given URI into the CRL Distribution Point
X.509 extension of server certificates.
--ocsp-uri uri Encode the given URI into the Authority Info Access
X.509 extension of server certificates as the OCSP
responder URI.
--write-memdumps-into-files
When dumping a piece of memory in the log, also output
its binary equivalent into a file called
hexdump_####.bin, where #### is an ascending number.
Useful for debugging of internal data structures.
--use-ipv6-encapsulation
For writing the PCAPNG file format, usually IPv4 is
emulated. This has the drawback that when one IPv4
endpoint serves multiple servers via the TLS Server
Name Indication extension, they cannot be
differentiated by their hostname. With this parameter,
ratched wraps the packets in IPv4-in-IPv6 emulation
and assigns different IPv6 addresses for different
server names, thus enabling accurate name resolution.
-l hostname:port, --listen hostname:port
Specify the address and port that ratched is listening
on. Defaults to 127.0.0.1:9999.
-d key=value[,key=value,...], --defaults key=value[,key=value,...]
Specify the server and client connection parameters
for all hosts that are not explicitly listed via a
--intercept option. Arguments are given in a key=value
fashion; valid arguments are shown below.
-i hostname[,key=value,...], --intercept hostname[,key=value,...]
Intercept only a specific host name, as indicated by
the Server Name Indication inside the ClientHello. Can
be specified multiple times to include interception or
more than one host. Additional arguments can be
specified in a key=value fashion to further define
interception parameters for that particular host.
--pcap-comment comment
Store a particular piece of information inside the
PCAPNG header as a comment.
-o filename, --outfile filename
Specifies the PCAPNG file that the intercepted traffic
is written to. Mandatory argument.
-v, --verbose Increase logging verbosity.
The arguments which are valid for the --intercept argument are as follows:
intercept=[opportunistic|mandatory|forward|reject]
Specifies the mode that ratched should act in for
this particular connection. Opportunistic TLS
interception is the default; it means that TLS
interception is tried first. Should it fail, however
(because someone tries to send non-TLS traffic), it
falls back to 'forward' mode (i.e., forwarding all
data unmodified). Mandatory TLS interception means
that if no TLS interception is possible, the
connection is terminated. 'forward', as explained,
simply forwards everything unmodified. 'reject'
closes the connection altogether, regardless of the
type of seen traffic.
s_tlsversions=versions
Colon-separated string that specifies the acceptable
TLS version for the ratched server component. Valid
elements are ssl2, ssl3, tls10, tls11, tls12, tls13.
Defaults to tls10:tls11:tls12.
s_reqclientcert=bool Ask all connecting clients to the server side of the
TLS proxy for a client certificate. If not
replacement certificate (at least certfile and
keyfile) is given, forge all metadata of the incoming
certificate. If a certfile/keyfile is given, this
option is implied.
s_send_rot=bool By default, the ratched TLS server does not include
its own root of trust (RoT) CA certificate in the
server certificates list. With this option, it is
added to the certificates sent to its peer.
s_certfile=filename Specifies an X.509 certificate in PEM format that
should be used by ratched as the server certificate.
By default, this certificate is automatically
generated. Must be used in conjunction with
s_keyfile.
s_keyfile=filename Specifies the private key for the given server
certificate, in PEM format.
s_chainfile=filename Specifies the X.509 certificate chain that is to be
sent to the client, in PEM format.
s_cacert=filename The X.509 CA certificate that issues server
certificates, in PEM format.
s_cakey=filename The X.509 CA certificate key that signs server
certificates, in PEM format.
s_ciphers=ciphers The cipher suite string that the ratched TLS server
uses.
s_groups=groups The key agreement 'supported groups' string (formerly
known as 'elliptic curves') that the ratched TLS
server uses.
s_sigalgs=algs The key agreement 'signature algorithms' string which
the ratched TLS server uses.
s_ocsp=bool Respond to clients requesting an OCSP status request
by sending an OCSP ticket as a response. Enabled by
default.
c_tlsversions=versions
Colon-separated string that specifies the acceptable
TLS version for the ratched client component. Valid
elements are ssl2, ssl3, tls10, tls11, tls12, tls13.
Defaults to tls10:tls11:tls12.
c_certfile=filename Specifies an X.509 certificate in PEM format that
should be used by ratched as a client certificate. It
will only be used when the connecting client also
provided a client certificate. Must be used in
conjunction with c_keyfile.
c_keyfile=filename The private key for the given client certificate, in
PEM format.
c_chainfile=filename The X.509 certificate chain that is to be sent to the
server, in PEM format.
c_ciphers=ciphers The cipher suite string that the ratched TLS client
uses.
c_groups=groups The key agreement 'supported groups' string (formerly
known as 'elliptic curves') that the ratched TLS
client uses.
c_sigalgs=algs The key agreement 'signature algorithms' string which
the ratched TLS client uses.
examples:
$ ratched -o output.pcapng
Open up local port 9999 and listen for incoming connections, intercept
all TLS traffic and write output into given capture file.
$ ratched -f google.com:443 -o output.pcapng
Same as before, but redirect all traffic of which the destination cannot
be determined (e.g., local connections to port 9999) to google.com on
port 443.
$ ratched -vvv --dump-certs -o output.pcapng
Be much more verbose during interception and also print out forged
certificates in the log.
$ ratched --defaults intercept=forward -intercept --intercept www.johannes-bauer.com -o output.pcapng
Do not generally intercept connections (but rather forward all traffic
unmodified) except for connections with Server Name Indication
www.johannes-bauer.com, on which interception is performed.
$ ratched --intercept www.johannes-bauer.com,s_reqclientcert=true -o output.pcapng
Generally do not request client certificates from connecting peers
except for connections with Server Name Indication www.johannes-
bauer.com, where clients are sent a CertificateRequest TLS message. If
clients do not provide a client certificate, just use regular TLS
interception. If they do provide a client certificate, forge all client
certificate metadata and use the forged client certificate in the
connection against the real server.
$ ratched --intercept www.johannes-bauer.com,c_certfile=joe.crt,c_keyfile=joe.key -o output.pcapng
Same as before, but for connections to johannes-bauer.com, do not forge
client certificates, but always use the given client certificate and key
(joe.crt / joe.key) for authentication against the server.
$ ratched --keyspec ecc:secp256r1 --ocsp-uri http://www.ocsp-server.com -o output.pcapng
Choose secp256r1 instead of RSA-2048 for all used certificates and
encode an OCSP Responder URI into those forged certificates as well.
$ ratched --initial-read-timeout 5.0 --default intercept=mandatory -o output.pcapng
Wait five seconds for connecting clients to send a valid ClientHello
message. If after five seconds nothing is received or if unknown (non-
TLS) traffic is received, terminate the connection instead of performing
unmodified forwarding.
Der Name „ratched“ spielt auf die Krankenschwester Ratched aus „Einer flog über das Kuckucksnest“ an. Wenn Sie das Werkzeug verwenden, um Leute zu bespitzeln, sind Sie ein komplettes Arschloch und missbrauchen Ihre Macht. Sie sollten sich den Film ansehen. Bitte verwenden Sie ratched verantwortungsvoll, um die Sicherheit unserer Infrastruktur zu erhöhen, nicht zu untergraben. TLS-Abfangen zu Spionagezwecken ist verabscheuungswürdig und gefährlich.
ratched benötigt mindestens OpenSSL v1.1.
ratched ist unter der GNU GPL-3 lizenziert.