johndoe31415/ratchedRatchedは、ペネトレーションテストを目的とした透過型Man-in-the-Middle TLSプロキシです。
ratched は TLS 接続を特別にインターセプトする Man-in-the-Middle (MitM) プロキシです。これは Linux の iptables REDIRECT ターゲットと組み合わせて使用することを意図しています。インターセプトすべきすべての接続は、ローカルの ratched ポートにリダイレクトできます。SO_ORIGINAL_DST ソケットオプションを通じて、ratched は意図された宛先（iptables によるパケット書き換え前）を特定し、元のターゲットへの接続を確立しようとします。
他の MitM ソフトウェアと異なる点は以下の通りです。
ratched は無差別にトラフィックをインターセプトしません。特に、最初に TLS クライアントが ClientHello を送信するのを待ち、ratched がそれを解析し、Server Name Indication (SNI) TLS 拡張によってターゲットをインターセプトすべきかどうかを判断します。これはバーチャルホスティング環境で、特定のホスト名への接続のみをインターセプトしたい場合に特に便利です。
ratched はパスワードのスニッフィングのみを目的とするのではなく、主にトラフィックを PCAPNG ファイルにダンプします。PCAPNG ファイル形式は、コメント付きで接続に注釈を付けられる（特に SNI 拡張で示されたホスト名）こと、またキャプチャファイルに名前解決情報を埋め込める（ターゲット IP アドレスを SNI 拡張のホスト名にマッピングするため）ことから選択されました。
ratched はインターセプトする SNI ごとに個別の設定を持ち、クライアント側とサーバー側のサポートされるグループ（旧称「サポートされる楕円曲線」）、暗号スイート、特定の TLS バージョンを含み、異なるインターセプトホストにカスタム証明書/鍵を指定できます。
ratched はクライアント証明書を広範にサポートし、クライアント証明書の自動偽造も提供します（反対方向の偽造サーバー証明書と同様）。
ratched は OCSP ステープリングをサポートし、クライアントがステータス要求 TLS 拡張を送信する場合に正の OCSP 応答を自動的に偽造できます。
ratched がルーティングマシン上で待機している場合（例ではポート 9999）、キャプチャしたいトラフィックを指定する iptables エントリを追加するだけです。たとえば、192.168.1.7 からポート 443 に到達しようとするすべてのトラフィックをインターセプトするには、以下を使用します。
# iptables -t nat -A PREROUTING -p tcp -s 192.168.1.7 --dport 443 -j REDIRECT --to-ports 9999
443 へのすべてのトラフィックをインターセプトするには、単に以下を実行します。
# iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-ports 9999
ルーターとして動作し、ローカルに到着するトラフィックをインターセプトしたい場合は、REDIRECT の代わりに DNAT ターゲットを使用します。例：
# iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 443 -j DNAT --to 192.168.123.1:9999
ここで、eth1 はトラフィックをインターセプトするインターフェースで、192.168.123.1 はローカルインターフェースの IP アドレスです。
ヘルプページはかなり自明でしょう。
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.
「ratched」という名前は、「カッコーの巣の上で」(One Flew Over The Cuckoo's Nest) のラチェッド看護師に由来します。もしこのツールを人をスパイするために使うなら、あなたは完全なクズであり、権力を乱用していることになります。映画を見るべきです。ratched を責任を持って使用し、インフラのセキュリティを 向上 させるために使い、それを損なわないでください。スパイ目的の TLS インターセプションは卑劣で危険です。
ratched には少なくとも OpenSSL v1.1 が必要です。
ratched は GNU GPL-3 の下でライセンスされています。