Repository: quarkslab/peetch Branch: master Commit: 2ec684d10368 Files: 15 Total size: 70.2 KB Directory structure: gitextract_b_gn6amn/ ├── Dockerfile ├── LICENSE.txt ├── README.md ├── doc/ │ └── notes.md ├── peetch/ │ ├── __init__.py │ ├── __main__.py │ ├── c_utils/ │ │ └── libssl.c │ ├── ebpf_programs/ │ │ ├── peetch_kprobes.c │ │ ├── peetch_proxy.c │ │ └── peetch_uprobes.c │ ├── globals.py │ ├── proxy.py │ └── utils.py ├── requirements.txt └── setup.py ================================================ FILE CONTENTS ================================================ ================================================ FILE: Dockerfile ================================================ # SPDX-License-Identifier: GPL-2.0+ # Guillaume Valadon FROM ubuntu:22.04 ENV TZ=Europe/Paris DEBIAN_FRONTEND=noninteractive RUN echo 'PS1="quarkslab/peetch:\w# "' >> /root/.bashrc # Install dependencies RUN set -x && \ PACKAGES="bison build-essential cmake flex git \ libedit-dev libllvm11 llvm-11-dev libclang-11-dev python3 zlib1g-dev \ libelf-dev libfl-dev python3-distutils python3-pip linux-headers-$(uname -r) \ libssl-dev iproute2 tmux curl bc libelf-dev zip tshark curl" && \ apt-get update && apt-get install -y $PACKAGES && \ apt-get autoclean && apt-get --purge -y autoremove && \ rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* # Compile bcc RUN git clone https://github.com/iovisor/bcc && cd bcc/ && mkdir build && \ cd build && cmake .. && make install && cd src && make install && rm -rf /bcc/ # Install peetch COPY . /peetch RUN cd /peetch && pip install --upgrade pip && pip install -r requirements.txt && \ pip install . && rm -rf /peetch ================================================ FILE: LICENSE.txt ================================================ GNU GENERAL PUBLIC LICENSE Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. 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If the program is interactive, make it output a short notice like this when it starts in an interactive mode: Gnomovision version 69, Copyright (C) year name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program. You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. , 1 April 1989 Ty Coon, President of Vice This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. ================================================ FILE: README.md ================================================ # peetch `peetch` is a collection of tools aimed at experimenting with different aspects of eBPF to bypass TLS protocol protections. Currently, peetch includes three subcommands. The first called `dump` aims to sniff network traffic by associating information about the source process with each packet. The second called `tls` allows identifying processes using OpenSSL to extract cryptographic keys. The third one `proxy` automatically intercepts TLS traffic from processes using OpenSSL and decrypts messages on the fly. Combined, the first two commands make it possible to decrypt TLS exchanges recorded in the PCAPng format. ## Installation `peetch` relies on several dependencies including [bcc](https://github.com/iovisor/bcc) and [Scapy](https://github.com/secdev/scapy). A Docker image can be easily built in order to easily test `peetch` using the following command: ```shell docker build -t quarkslab/peetch . ``` ## Commands Walk Through The following examples assume that you used the following command to enter the Docker image and launch examples within it: ```shell docker run --privileged --network host --mount type=bind,source=/sys,target=/sys --mount type=bind,source=/proc,target=/proc --pid host --rm -it quarkslab/peetch ``` ### `dump` This sub-command gives you the ability to sniff packets using an eBPF TC classifier and to retrieve the corresponding PID and process names with: ```shell peetch dump curl/1289291 - Ether / IP / TCP 10.211.55.10:53052 > 208.97.177.124:https S / Padding curl/1289291 - Ether / IP / TCP 208.97.177.124:https > 10.211.55.10:53052 SA / Padding curl/1289291 - Ether / IP / TCP 10.211.55.10:53052 > 208.97.177.124:https A / Padding curl/1289291 - Ether / IP / TCP 10.211.55.10:53052 > 208.97.177.124:https PA / Raw / Padding curl/1289291 - Ether / IP / TCP 208.97.177.124:https > 10.211.55.10:53052 A / Padding ``` Note that as of today, `dump` will only capture IPv4 based TCP segments. For convenience, the captured packets can be store to PCAPng along with process information using `--write`: ```shell peetch dump --write peetch.pcapng ^C ``` This PCAPng can easily be manipulated with Wireshark or Scapy: ```python scapy >>> l = rdpcap("peetch.pcapng") >>> l[0] >>> >>> l[0].comment b'curl/1289909' ``` ### `tls` This sub-command aims to identify processes that uses OpenSSL and makes it easy to dump several things like plaintext and secrets. By default, `peetch tls` will only display one line per process, the `--directions` argument makes it possible to display the exchanged messages: ```shell peetch tls --directions <- curl (1291078) 208.97.177.124/443 TLS1.2 ECDHE-RSA-AES128-GCM-SHA256 -> curl (1291078) 208.97.177.124/443 TLS1.2 ECDHE-RSA-AES128-GCM-SHA256 ``` Displaying OpenSSL buffer content is achieved with `--content`. ```shell peetch tls --content <- curl (1290608) 208.97.177.124/443 TLS1.2 ECDHE-RSA-AES128-GCM-SHA256 0000 47 45 54 20 2F 20 48 54 54 50 2F 31 2E 31 0D 0A GET / HTTP/1.1.. 0010 48 6F 73 74 3A 20 77 77 77 2E 70 65 72 64 75 2E Host: www.perdu. 0020 63 6F 6D 0D 0A 55 73 65 72 2D 41 67 65 6E 74 3A com..User-Agent: 0030 20 63 75 72 6C 2F 37 2E 36 38 2E 30 0D 0A 41 63 curl/7.68.0..Ac -> curl (1290608) 208.97.177.124/443 TLS1.2 ECDHE-RSA-AES128-GCM-SHA256 0000 48 54 54 50 2F 31 2E 31 20 32 30 30 20 4F 4B 0D HTTP/1.1 200 OK. 0010 0A 44 61 74 65 3A 20 54 68 75 2C 20 31 39 20 4D .Date: Thu, 19 M 0020 61 79 20 32 30 32 32 20 31 38 3A 31 36 3A 30 31 ay 2022 18:16:01 0030 20 47 4D 54 0D 0A 53 65 72 76 65 72 3A 20 41 70 GMT..Server: Ap ``` The `--secrets` arguments will display TLS Master Secrets extracted from memory. The following example leverages `--write` to write master secrets to simplify decrypting TLS messages with Scapy: ```shell (sleep 5; curl https://www.perdu.com/?name=highly%20secret%20information --tls-max 1.2 --http1.1 --tlsv1.2) & peetch tls --write & curl (1293232) 208.97.177.124/443 TLS1.2 ECDHE-RSA-AES128-GCM-SHA256 peetch dump --write traffic.pcapng ^C # Add the master secret to a PCAPng file editcap --inject-secrets tls,1293232-master_secret.log traffic.pcapng traffic-ms.pcapng scapy >>> load_layer("tls") >>> conf.tls_session_enable = True >>> l = rdpcap("traffic-ms.pcapng") >>> l[13][TLS].msg [] ``` ### `proxy` This sub-command uses eBPF programs to automatically intercept TLS traffic from processes using OpenSSL and decrypt messages on the fly using Scapy. In the following example, `peetch proxy` display a secret value sent to a server by the `openssl` process. ```shell peetch proxy [-] Proxying OpenSSL traffic [+] Intercepting traffic from openssl/451255 to 172.67.133.176/443 via 127.0.0.1/58039 --> 127.0.0.1:58039 > 172.67.133.176:https tcp <-- 172.67.133.176:https > 127.0.0.1:58039 tcp --> 127.0.0.1:58039 > 172.67.133.176:https tcp <-- 172.67.133.176:https > 127.0.0.1:58039 tcp --> 127.0.0.1:58039 > 172.67.133.176:https tcp --> 127.0.0.1:58039 > 172.67.133.176:https tcp ###[ TLS Application Data ]### data = b'GET /?secret=9590 HTTP/1.1\r\nHost: www.perdu.com\r\n\r\n\n' ``` ## Limitations By design, `peetch` only supports OpenSSL, IPv4 and TLS 1.2. ================================================ FILE: doc/notes.md ================================================ # Notes This document contains various information used to debug and test `peetch` features. # Tests * `openssl s_client` ``` rm secrets.txt ; (sleep 1 ;echo -e "GET /?secret=$RANDOM HTTP/1.1\r\nHost: www.perdu.com\r\n\r\n") |openssl s_client -connect www.perdu.com:443 -keylogfile secrets.txt -no_tls1_3 -4; cat secrets.txt ``` * test the connectin to the proxy ``` curl --connect-to www.perdu.com:443:127.0.0.1:2807 https://www.perdu.com ``` * libcurl binaries ``` # TLS1.2 & HTTP/1.1 curl https://echo.free.beeceptor.com/?secret_number=$RANDOM --tls-max 1.2 --http1.1 --tlsv1.2 --libcurl secret_binary.c cc -o secret_binary secret_binary.c -lssl -lcurl && ./secret_binary # TLS1.2 & HTTP/2.0 curl https://echo.free.beeceptor.com/?secret_number=$RANDOM --tls-max 1.2 --http2 --tlsv1.2 --libcurl secret_binary2.c cc -o secret_binary2 secret_binary2.c -lssl -lcurl && ./secret_binary2 ``` # OpenSSL Offsets The following radare2 commands could be used to validate the OpenSSL offsets dynamically generated by `peetch`: ``` cat curl.rr2 #!/usr/bin/rarun2 program=/usr/bin/curl arg0=5 arg1=--tls-max arg2=1.2 arg3=--tlsv1.2 arg4=--http1.1 arg5=https://www.perdu.com radare2 -e dbg.profile=curl.rr2 -A -d /usr/bin/curl [...]> dcu sym.imp.curl_globa_init [...]> dmi libssl SSL_read [...]> dmi libssl SSL_write [...]> db 0xffffa479eeb4 # address of SSL_read [...]> db 0xffff9086f504 # address of SSL_write [...]> dc [...]> px 48 @ `pv @ x0 + 0x918` + 0x50 # offset off ssl_session and master_secret - offset - 6061 6263 6465 6667 6869 6A6B 6C6D 6E6F 0123456789ABCDEF 0xaaab0a47aa60 ce6a 7675 5e95 dfd4 e5ed 10c1 c0b7 9bd9 .jvu^........... 0xaaab0a47aa70 808f 416a 13ef cb29 6c8e 323a 40cb e5ea ..Aj...)l.2:@... 0xaaab0a47aa80 ccdb 09d2 7f46 7fb9 7115 6082 f4dc 2725 .....F..q.`...'% ``` ``` ================================================ FILE: peetch/__init__.py ================================================ # SPDX-License-Identifier: GPL-2.0+ # Guillaume Valadon import argparse import asyncio import atexit import ctypes as ct import binascii import os import socket import struct import sys import time from bcc import BPF, BPFProgType, BPFAttachType import pyroute2 from scapy.all import Ether, wrpcapng, hexdump, load_layer, conf import peetch.globals from peetch.proxy import all_tasks import peetch.utils load_layer("tls") conf.tls_session_enable = True global BPF_HANDLER, BPF_TLS_HANDLER EBPF_PROGRAMS_DIRNAME = os.path.join(os.path.dirname(__file__), "ebpf_programs/") BPF_DUMP_PROGRAM_FILENAME = "%s/peetch_kprobes.c" % EBPF_PROGRAMS_DIRNAME BPF_DUMP_PROGRAM_SOURCE = open(BPF_DUMP_PROGRAM_FILENAME).read() BPF_TLS_PROGRAM_FILENAME = "%s/peetch_uprobes.c" % EBPF_PROGRAMS_DIRNAME BPF_TLS_PROGRAM_SOURCE = open(BPF_TLS_PROGRAM_FILENAME).read() BPF_PROXY_PROGRAM_FILENAME = "%s/peetch_proxy.c" % EBPF_PROGRAMS_DIRNAME BPF_PROXY_PROGRAM_SOURCE = open(BPF_PROXY_PROGRAM_FILENAME).read() PACKETS_CAPTURED = [] TLS_INFORMATION = {} def load_classifier(interface, ebpf_function): """ Load an eBPF TC Classifier """ iproute_handler = pyroute2.IPRoute() ip_link = iproute_handler.link_lookup(ifname=interface) if not ip_link: sys.exit() ip_link = ip_link[0] iproute_handler.tc("add", "clsact", ip_link) # add ingress clsact iproute_handler.tc("add-filter", "bpf", ip_link, ":1", fd=ebpf_function.fd, name=ebpf_function.name, parent="ffff:fff2") # add egress clsact iproute_handler.tc("add-filter", "bpf", ip_link, ":1", fd=ebpf_function.fd, name=ebpf_function.name, parent="ffff:fff3") def unload_classifier(interface): """ Unload an eBPF TC Classifier """ os.system("tc qdisc del dev %s clsact" % args.interface) def exit_handler_command(interface, filename, bpf_handler): """ Exit command nicely """ time.sleep(0.01) bpf_handler.detach_kprobe(event="security_sk_classify_flow", fn_name="kprobe_security_sk_classify_flow") unload_classifier(interface) if filename: wrpcapng(filename, PACKETS_CAPTURED) def exit_handler_proxy(bpf_handler, connect_function, cgroup_fd): """ Exit proxy nicely """ time.sleep(0.01) bpf_handler.detach_func(connect_function, cgroup_fd, BPFAttachType.CGROUP_INET4_CONNECT) if cgroup_fd > 0: os.close(cgroup_fd) def handle_skb_event(cpu, data, size): """ Handle SKB events from the kernel """ # Structure retrieved from the kernel class SkbEvent(ct.Structure): _fields_ = [("pid", ct.c_uint32), ("raw", ct.c_ubyte * (size - ct.sizeof(ct.c_uint32)))] # Map the data from kernel to the structure skb_event = ct.cast(data, ct.POINTER(SkbEvent)).contents data = bytes(skb_event.raw) # Extract the process name for i in range(len(data)): if data[i] == 0: break process_name = data[:i].decode("utf-8", "replace") data = data[16:] process_information = "%s/%d" % (process_name, skb_event.pid) # Parse the packet with Scapy pkt = Ether(data) if args.write: pkt.comment = str(process_information) PACKETS_CAPTURED.append(pkt) else: if not args.raw: print(process_information, end=" - ") print(pkt.summary()) def dump_command(args): # Compile eBPF programs bpf_handler = BPF(text=BPF_DUMP_PROGRAM_SOURCE) # Attach the kprobe bpf_handler.attach_kprobe(event="security_sk_classify_flow", fn_name="kprobe_security_sk_classify_flow") # Setup the exit handler atexit.register(exit_handler_command, args.interface, args.write, bpf_handler) # Load eBPF TC Classifier classifier_function = bpf_handler.load_func("process_frame", BPF.SCHED_CLS) load_classifier(args.interface, classifier_function) # Handle incoming skb events bpf_handler["skb_events"].open_perf_buffer(handle_skb_event) try: while True: bpf_handler.perf_buffer_poll() except KeyboardInterrupt: pass def handle_tls_event(cpu, data, size): class TLSEvent(ct.Structure): _fields_ = [("address", ct.c_uint32), ("port", ct.c_uint16), ("tls_version", ct.c_uint16), ("comm", ct.c_char * 64), ("message", ct.c_uint8 * 64), ("message_length", ct.c_uint32), ("pid", ct.c_uint32), ("is_read", ct.c_uint32)] # Map the data from kernel to the structure tls_event = ct.cast(data, ct.POINTER(TLSEvent)).contents # Get TLS information pid_to_delete = None master_secret = None ciphersuite = None bpf_map_tls_information = BPF_TLS_HANDLER["tls_information_cache"] for pid, tls_info in bpf_map_tls_information.items_lookup_batch(): if pid.value == tls_event.pid: ciphersuite = tls_info.ciphersuite.decode("ascii", "ignore") master_secret = binascii.hexlify(tls_info.master_secret) master_secret = master_secret.decode("ascii", "ignore") pid_to_delete = [pid] break # Delete pid from the eBPF map if not pid_to_delete: bpf_map_tls_information.items_delete_batch(pid_to_delete) # Unpack the IPv4 destination address addr = struct.pack("I", tls_event.address) # Discard empty content if args.content and tls_event.message_length == 0: return # Display the TLS event if args.directions: if tls_event.is_read: print("->", end=" ") else: print("<-", end=" ") print("%s (%d)" % (tls_event.comm.decode("ascii", "replace"), tls_event.pid), end=" ") print("%s/%d" % (socket.inet_ntop(socket.AF_INET, addr), socket.ntohs(tls_event.port)), end=" ") version = (tls_event.tls_version & 0xF) - 1 print("TLS1.%d %s" % (version, ciphersuite)) # Display TLS secrets if (args.secrets or args.write) and tls_event.tls_version == 0x303: key_log = "CLIENT_RANDOM 28071980 %s\n" % master_secret if args.secrets: print("\n %s\n" % key_log) if args.write: fd = open("%d-master_secret.log" % pid.value, "w") fd.write(key_log) fd.close() # Display the message content in hexadecimal if args.content and tls_event.message_length: hex_message = hexdump(tls_event.message[:tls_event.message_length], dump=True) print("\n ", end="") print(hex_message.replace("\n", "\n ")) print() def _tls_ebpf_programs(directions_bool, args_ssl_session_offset, args_ssl_cipher_offset, args_master_secret_offset, args_client_hello_offset, args_client_random_offset): # Get SSL structures offsets offsets = [str(offset) for offset in peetch.utils.get_offsets()] ssl_session_offset, ssl_cipher_offset, master_secret_offset, \ client_hello_offset, client_random_offset = offsets if ssl_session_offset == ssl_cipher_offset and \ ssl_cipher_offset == master_secret_offset and master_secret_offset == '0': # noqa: E501 return None if args_ssl_session_offset is not None: ssl_session_offset = str(args_ssl_session_offset) if args_ssl_cipher_offset is not None: ssl_cipher_offset = str(args_ssl_cipher_offset) if args_master_secret_offset is not None: master_secret_offset = str(args_master_secret_offset) if args_client_hello_offset is not None: client_hello_offset = str(args.client_hello_offset) if args_client_random_offset is not None: client_random_offset = str(args.client_random_offset) # Compile eBPF programs ebpf_programs = BPF_TLS_PROGRAM_SOURCE.replace("DIRECTIONS", directions_bool) ebpf_programs = ebpf_programs.replace("SSL_SESSION_OFFSET", ssl_session_offset) ebpf_programs = ebpf_programs.replace("MASTER_SECRET_OFFSET", master_secret_offset) ebpf_programs = ebpf_programs.replace("SSL_CIPHER_OFFSET", ssl_cipher_offset) ebpf_programs = ebpf_programs.replace("CLIENT_HELLO_OFFSET", client_hello_offset) ebpf_programs = ebpf_programs.replace("CLIENT_RANDOM_OFFSET", client_random_offset) return ebpf_programs def tls_command(args): global BPF_TLS_HANDLER # Process arguments if args.content: args.directions = True directions_bool = "1" if args.directions: directions_bool = "0" ebpf_programs = _tls_ebpf_programs(directions_bool, args.ssl_session_offset, args.ssl_cipher_offset, args.master_secret_offset, args.client_hello_offset, args.client_random_offset) if ebpf_programs is None: print("ERROR: cannot guess SSL offsets!", file=sys.stderr) sys.exit(1) bpf_handler = BPF(text=ebpf_programs) BPF_TLS_HANDLER = bpf_handler # Attach the probes try: bpf_handler.attach_uprobe(name="ssl", sym="SSL_write", fn_name="SSL_write") bpf_handler.attach_uprobe(name="ssl", sym="SSL_read", fn_name="SSL_read") bpf_handler.attach_uretprobe(name="ssl", sym="SSL_read", fn_name="SSL_read_ret") except Exception: print("tls - cannot attach to eBPF probes!") sys.exit() def handle_tls_event(cpu, data, size): class TLSEvent(ct.Structure): _fields_ = [("address", ct.c_uint32), ("port", ct.c_uint16), ("tls_version", ct.c_uint16), ("comm", ct.c_char * 64), ("message", ct.c_uint8 * 64), ("message_length", ct.c_uint32), ("pid", ct.c_uint32), ("is_read", ct.c_uint32)] # Map the data from kernel to the structure tls_event = ct.cast(data, ct.POINTER(TLSEvent)).contents # Get TLS information pid_to_delete = None master_secret = None ciphersuite = None client_random = None bpf_map_tls_information = bpf_handler["tls_information_cache"] for pid, tls_info in bpf_map_tls_information.items_lookup_batch(): if pid.value == tls_event.pid: ciphersuite = tls_info.ciphersuite.decode("ascii", "ignore") master_secret = binascii.hexlify(tls_info.master_secret) master_secret = master_secret.decode("ascii", "ignore") client_random = binascii.hexlify(tls_info.client_random) client_random = client_random.decode("ascii", "ignore") pid_to_delete = [pid] break # Delete pid from the eBPF map if not pid_to_delete: bpf_map_tls_information.items_delete_batch(pid_to_delete) # Unpack the IPv4 destination address addr = struct.pack("I", tls_event.address) # Discard empty content if args.content and tls_event.message_length == 0: return # Display the TLS event if args.directions: if tls_event.is_read: print("->", end=" ") else: print("<-", end=" ") print("%s (%d)" % (tls_event.comm.decode("ascii", "replace"), tls_event.pid), end=" ") print("%s/%d" % (socket.inet_ntop(socket.AF_INET, addr), socket.ntohs(tls_event.port)), end=" ") version = (tls_event.tls_version & 0xF) - 1 print("TLS1.%d %s" % (version, ciphersuite)) # Display TLS secrets if (args.secrets or args.write) and tls_event.tls_version == 0x303: key_log = "CLIENT_RANDOM %s %s\n" % (client_random, master_secret) if args.secrets: print("\n %s\n" % key_log) if args.write: fd = open("%d-master_secret.log" % pid.value, "w") fd.write(key_log) fd.close() # Display the message content in hexadecimal if args.content and tls_event.message_length: hex_message = hexdump(tls_event.message[:tls_event.message_length], dump=True) print("\n ", end="") print(hex_message.replace("\n", "\n ")) print() bpf_handler["tls_events"].open_perf_buffer(handle_tls_event) while True: try: bpf_handler.perf_buffer_poll() except KeyboardInterrupt: sys.exit() def proxy_command(args): # Compile eBPF programs ebpf_programs = BPF_PROXY_PROGRAM_SOURCE.replace("PEETCH_PROXY_PID", str(os.getpid())) bpf_handler = BPF(text=ebpf_programs) peetch.globals.BPF_HANDLER = bpf_handler # Load the eBPF function connect_function = bpf_handler.load_func("connect_v4_prog", prog_type=BPFProgType.CGROUP_SOCK_ADDR, # noqa: E501 attach_type=BPFAttachType.CGROUP_INET4_CONNECT) # noqa: E501 # Attach the eBPF function to the default cgroup cgroup_fd = os.open("/sys/fs/cgroup", os.O_RDONLY) bpf_handler.attach_func(connect_function, cgroup_fd, BPFAttachType.CGROUP_INET4_CONNECT) # Attach the SSL_* uprobes ebpf_programs = _tls_ebpf_programs("1", None, None, None, None, None) if ebpf_programs is None: print("ERROR: cannot guess SSL offsets!", file=sys.stderr) sys.exit(1) bpf_tls_handler = BPF(text=ebpf_programs) peetch.globals.BPF_TLS_HANDLER = bpf_tls_handler try: bpf_tls_handler.attach_uprobe(name="ssl", sym="SSL_write", fn_name="SSL_write") bpf_tls_handler.attach_uprobe(name="ssl", sym="SSL_read", fn_name="SSL_read") bpf_tls_handler.attach_uretprobe(name="ssl", sym="SSL_read", fn_name="SSL_read_ret") # noqa: E501 except Exception: print("proxy - cannot attach to eBPF SSL_* uprobes!") sys.exit() print("[-] Proxying OpenSSL traffic") # Setup the exit handler atexit.register(exit_handler_proxy, bpf_handler, connect_function, cgroup_fd) # Start the proxy try: asyncio.run(all_tasks(args.debug)) except KeyboardInterrupt: pass def main(): global args argv = sys.argv[1:] # Parsing arguments parser = argparse.ArgumentParser(description="peetch - an eBPF playground") subparser = parser.add_subparsers() parser.set_defaults(func=lambda args: parser.print_help()) # Prepare the 'dump' subcommand dump_parser = subparser.add_parser("dump", help="Sniff packets with eBPF") dump_parser.add_argument("--raw", action="store_true", help="display packets only") dump_parser.add_argument("--write", type=str, help="pcapng filename") dump_parser.add_argument("--interface", type=str, help="interface name", default=str(conf.iface)) dump_parser.set_defaults(func=dump_command) # Prepare the 'tls' subcommand tls_parser = subparser.add_parser("tls", help="Identify processes that uses TLS") tls_parser.add_argument("--directions", action="store_true", help="display read & write calls") tls_parser.add_argument("--content", action="store_true", help="display buffers content") tls_parser.add_argument("--secrets", action="store_true", help="display TLS secrets") tls_parser.add_argument("--write", action="store_true", help="write TLS secrets to files") tls_parser.add_argument("--ssl_session_offset", help="offset to the ssl_session_t structure") tls_parser.add_argument("--master_secret_offset", help="offset to the master secret in an ssl_session_t structure") # noqa: E501 tls_parser.add_argument("--ssl_cipher_offset", help="offset to the ssl_cipher structure in an ssl_session_t structure") # noqa: E501 tls_parser.add_argument("--client_hello_offset", help="offset to the CLIENTHELLO_MSG structure in an ssl structure") # noqa: E501 tls_parser.add_argument("--client_random_offset", help="offset to the client random in an CLIENTHELLO_MSG structure") # noqa: E501 tls_parser.set_defaults(func=tls_command) # Prepare the 'proxy' subcommand proxy_parser = subparser.add_parser("proxy", help="Automatically intercept TLS connections") # noqa: E501 proxy_parser.add_argument("--debug", action="store_true", help="display debug information") proxy_parser.set_defaults(func=proxy_command) # Print the Help message when no arguments are provided if not argv: parser.print_help(sys.stderr) sys.exit(1) # Call the sub-command args = parser.parse_args(argv) args.func(args) ================================================ FILE: peetch/__main__.py ================================================ #!/usr/bin/env python3 # SPDX-License-Identifier: GPL-2.0+ # Guillaume Valadon from . import main main() ================================================ FILE: peetch/c_utils/libssl.c ================================================ // SPDX-License-Identifier: GPL-2.0+ // Guillaume Valadon #include #include #include #include #define STRUCTURE_SIZE 8192 struct libssl_offsets_t { uint64_t ssl_session; uint64_t ssl_cipher; uint64_t master_secret; uint64_t client_hello; uint64_t client_random; }; struct libssl_offsets_t libssl_offsets(char *ip4_address, uint16_t port) { struct libssl_offsets_t offsets = { .ssl_session = 0, .ssl_cipher = 0, .master_secret = 0}; // Create the SSL context and set the TLS version const SSL_METHOD *method = TLS_client_method(); SSL_CTX *ctx = SSL_CTX_new(method); int ret = SSL_CTX_set_max_proto_version(ctx, TLS1_2_VERSION); if (ret < 0) { printf("SSL_CTX_set_max_proto_version() error - %d\n", ret); return offsets; } // Set up a TLS connection to get the SSL session structure SSL *ssl = SSL_new(ctx); int fd = socket(AF_INET, SOCK_STREAM, 0); if (fd < 0) { printf("socket() error - %d\n", fd); return offsets; } struct sockaddr_in addr; addr.sin_family = AF_INET; addr.sin_port = htons(port); ret = inet_aton(ip4_address, (struct in_addr*) &addr.sin_addr.s_addr); if (ret < 0) { printf("inet_aton() error - %d\n", fd); return offsets; } ret = connect(fd, (struct sockaddr*) &addr, sizeof(addr)); if (ret < 0) { printf("connect() error - %d\n", fd); return offsets; } ret = SSL_set_fd(ssl, fd); if (ret < 0) { printf("SSL_set_fd() error - %d\n", fd); return offsets; } ret = SSL_connect(ssl); if (ret < 0) { printf("SSL_connect() error - %d\n", fd); return offsets; } // SSL_SESSION* offset SSL_SESSION *session = SSL_get_session(ssl); for (uint64_t i = 0x000; i < STRUCTURE_SIZE; i++) { uint64_t value = (uint64_t) ssl + i; uint64_t *ptr = (uint64_t*) value; if ((uint64_t) *ptr == (uint64_t) session) { offsets.ssl_session = i; break; } } // SSL_CIPHER* offset const SSL_CIPHER *cipher = SSL_get_current_cipher(ssl); for (uint64_t i = 0x000; i < STRUCTURE_SIZE; i++) { uint64_t value = (uint64_t) session + i; uint64_t *ptr = (uint64_t*) value; if ((uint64_t) *ptr == (uint64_t) cipher) { offsets.ssl_cipher = i; break; } } // TLS 1.2 MASTER_SECRET offset uint8_t master_secret[48]; ret = SSL_SESSION_get_master_key(session, (unsigned char*)&master_secret, sizeof(master_secret)); if (ret != 48) { printf("SSL_SESSION_get_master_key() error - %d\n", fd); return offsets; } for (uint64_t i=0x000; i < STRUCTURE_SIZE; i++) { uint64_t value = (uint64_t) session + i; uint64_t *ptr = (uint64_t*) value; value = (uint64_t) session + i + 47; uint64_t *ptr_end = (uint64_t*) value; if ((*ptr & 0xFF) == master_secret[0] && \ (*ptr_end & 0xFF) == master_secret[47]) { offsets.master_secret = i; break; } } // Client Random offset uint8_t client_random[32]; offsets.client_hello = 0; ret = SSL_get_client_random(ssl, (unsigned char*)&client_random, sizeof(client_random)); if (ret != 32) { printf("SSL_get_client_random() error - %d\n", fd); return offsets; } for (uint64_t i=0; i < STRUCTURE_SIZE; i++) { if (offsets.client_hello != 0) break; uint64_t value = (uint64_t) ssl + i; uint64_t *ptr = (uint64_t*) value; if (*ptr) { for (uint8_t j=0; j < sizeof(STRUCTURE_SIZE) ; j++) { uint8_t *new_ptr = (uint8_t*) ptr + j; if ((new_ptr[0] & 0xFF) == client_random[0] && \ (new_ptr[31] & 0xFF) == client_random[31]) { offsets.client_hello = i; offsets.client_random = j; break; } } } } return offsets; } int main() { /* Compile it with: cc -o libssl_offsets libssl.c -lssl */ struct libssl_offsets_t offsets = libssl_offsets("1.1.1.1", 443); printf("--ssl_session_offset=0x%lx\n", offsets.ssl_session); printf("--ssl_cipher_offset=0x%lx\n", offsets.ssl_cipher); printf("--master_secret_offset=0x%lx\n", offsets.master_secret); printf("--client_hello=0x%lx\n", offsets.client_hello); printf("--client_random=0x%lx\n", offsets.client_random); return EXIT_SUCCESS; } ================================================ FILE: peetch/ebpf_programs/peetch_kprobes.c ================================================ // SPDX-License-Identifier: GPL-2.0+ // Guillaume Valadon #include #include #include #include #include #include #include struct key_t { u32 dst; u32 src; }; struct data_t { u32 pid; char name[TASK_COMM_LEN]; }; BPF_HASH(pid_cache, struct key_t, struct data_t); BPF_PERF_OUTPUT(skb_events); int process_frame(struct __sk_buff *skb) { // Data accessors unsigned char *data = (void *)(long)skb->data; unsigned char *data_end = (void *)(long)skb->data_end; // Mapping data to the Ethernet and IP headers struct ethhdr *eth = (struct ethhdr *)data; struct iphdr *iph = (struct iphdr*) (data + sizeof(struct ethhdr)); // Simple length check if ((data + sizeof(struct ethhdr) + sizeof(struct iphdr)) > data_end) return TC_ACT_OK; // Discard everything but IPv4 if (ntohs(eth->h_proto) != ETH_P_IP) return TC_ACT_OK; // Discard everything but TCP if (iph->protocol != IPPROTO_TCP) return TC_ACT_OK; // Retrieve the PID and the process name from the IP addresses struct key_t key = { .dst = iph->daddr, .src = iph->saddr }; struct data_t *value = (struct data_t *) pid_cache.lookup(&key); if (value == NULL) { key.dst = iph->saddr; key.src = iph->daddr; value = (struct data_t *) pid_cache.lookup(&key); if (value == NULL) return TC_ACT_OK; } // Check the PID if (value->pid == 0) return TC_ACT_OK; struct data_t tmp; __builtin_memset(&tmp, 0, sizeof(tmp)); // it makes the eBPF verifier happy! tmp.pid = value->pid; for (u8 i=0; i < TASK_COMM_LEN; i++) tmp.name[i] = value->name[i]; skb_events.perf_submit_skb(skb, skb->len, &tmp, sizeof(tmp)); return TC_ACT_OK; } int kprobe_security_sk_classify_flow(struct pt_regs *ctx, struct sock *sk, struct flowi *fl) { // Discard everything but IPv4 if (sk->sk_family != AF_INET) return 0; // Extract IPv4 related structures union flowi_uli uli; struct flowi4 ip4; bpf_probe_read(&ip4, sizeof(ip4), &fl->u.ip4); bpf_probe_read(&uli, sizeof(uli), &ip4.uli); // Get IP addresses and ports struct key_t key; struct data_t data; // it makes the eBPF verifier happy! __builtin_memset(&key, 0, sizeof(key)); __builtin_memset(&data, 0, sizeof(data)); bpf_probe_read(&key.src, sizeof(sk->__sk_common.skc_daddr), &sk->__sk_common.skc_daddr); bpf_probe_read(&key.dst, sizeof(sk->__sk_common.skc_rcv_saddr), &sk->__sk_common.skc_rcv_saddr); // Get and store the PID u64 id = bpf_get_current_pid_tgid(); data.pid = id >> 32; // Get and store the process name bpf_get_current_comm(data.name, sizeof(data.name)); // Store data pid_cache.update(&key, &data); return 0; } ================================================ FILE: peetch/ebpf_programs/peetch_proxy.c ================================================ // SPDX-License-Identifier: GPL-2.0+ // Guillaume Valadon #include #include struct data_t { u32 pid; char name[64]; u32 ip; u32 port; }; BPF_HASH(pid_cache, u64); BPF_HASH(destination_cache, u16, struct data_t); int connect_v4_prog(struct bpf_sock_addr *ctx) { struct data_t data; // Get and store the PID u64 id = bpf_get_current_pid_tgid(); data.pid = id >> 32; // Do not intercept connection from peetch itself if (PEETCH_PROXY_PID == data.pid) return 1; // Do not intercept well known TCP services if (ctx->user_port == bpf_htons(53)) // DNS return 1; // Check if the PID is in the cache u64 *tmp_id = pid_cache.lookup((u64*) &id); if (tmp_id == NULL) return 1; if (*tmp_id != id) return 1; // Get and store the process name bpf_get_current_comm(data.name, 64); // Rewrite the source port struct sockaddr_in sa = {}; sa.sin_family = AF_INET; u16 new_port = bpf_htons(data.pid & 0xFFFF); // lower part of the PID will be used as the TCP source port sa.sin_port = new_port; sa.sin_addr.s_addr = bpf_htonl(0x7f000001); // 127.0.0.1 if (bpf_bind(ctx, (struct sockaddr *) &sa, sizeof(sa)) != 0) return 0; // Get and store the real destination IPv4 address and port data.ip = ctx->user_ip4; data.port = ctx->user_port; // Store the connection data into the cache destination_cache.update(&new_port, &data); // Divert the connection to peetch proxy ctx->user_ip4 = 0x0100007f; ctx->user_port = bpf_htons(2807); /* Note: - 1: accept - 0: discard */ return 1; } TRACEPOINT_PROBE(syscalls, sys_enter_openat) { #define _PATH_MAX 128 char filename[_PATH_MAX + 1]; // Retrieve the filename long ret = bpf_probe_read((void*)&filename, _PATH_MAX, (void*)args->filename); if (ret != 0) { //bpf_trace_printk("sys_enter_openat() - bpf_probe_read() failed\n"); return 0; } // Check if the filename contains "libssl.so" for (u16 i=8; i < _PATH_MAX; i++) { if (filename[i-8] == 'l' && filename[i-7] == 'i' && filename[i-6] == 'b' && filename[i-5] == 's' && filename[i-4] == 's' && filename[i-3] == 'l' && filename[i-2] == '.' && filename[i-1] == 's') { // Get and store the PID u64 id = bpf_get_current_pid_tgid(); u64 pid = id >> 32; pid_cache.update(&id, &id); break; } } return 0; } ================================================ FILE: peetch/ebpf_programs/peetch_uprobes.c ================================================ // SPDX-License-Identifier: GPL-2.0+ // Guillaume Valadon #include #include // Data structure sent to userland struct tls_event_t { u32 addr; u16 port; u16 tls_version; #define COMM_MAX_LEN 64 char comm[COMM_MAX_LEN]; #define MESSAGE_MAX_LEN 64 u8 message[MESSAGE_MAX_LEN]; u32 message_length; u32 pid; u32 is_read; }; BPF_PERF_OUTPUT(tls_events); // Store SSL_* buffer information struct SSL_buffer_t { u64 ptr; u32 length; u32 tls_version; u32 is_read; }; BPF_HASH(SSL_read_buffers, u32, struct SSL_buffer_t); // Store connect information indexed by PID BPF_HASH(pid_cache, u32); // TLS information struct TLS_information_t { u16 tls_version; #define CIPHERSUITE_MAX_LEN 32 char ciphersuite[CIPHERSUITE_MAX_LEN]; #define MASTER_SECRET_MAX_LEN 48 u8 master_secret[MASTER_SECRET_MAX_LEN]; #define CLIENT_RANDOM_MAX_LEN 32 u8 client_random[CLIENT_RANDOM_MAX_LEN]; }; BPF_HASH(tls_information_cache, u32, struct TLS_information_t); TRACEPOINT_PROBE(syscalls, sys_enter_connect) { // Retrieve the sockaddr_in structure struct sockaddr_in addr_in; long ret = bpf_probe_read((void*)&addr_in, sizeof(addr_in), args->uservaddr); if (ret != 0) { bpf_trace_printk("sys_enter_connect() - bpf_probe_read() failed\n"); return 0; } // Discard everything but IPv4 if (addr_in.sin_family != AF_INET) return 0; // Retrieve the PID u32 pid = bpf_get_current_pid_tgid() & 0xFFFFFFFF; // Store a TLS event in the pid_cache struct tls_event_t event = { .port = addr_in.sin_port, .addr = addr_in.sin_addr.s_addr}; pid_cache.update(&pid, (u64*)&event); return 0; } // Dummy openssl ssl_st structure struct ssl_st { int version; }; static u16 get_tls_version(void *ssl_st_ptr) { // Extract the TLS version from a struct ssl_str pointer struct ssl_st ssl; long ret = bpf_probe_read(&ssl, sizeof(ssl), ssl_st_ptr); if (ret != 0) { bpf_trace_printk("get_tls_version() - bpf_probe_read() failed\n"); return -1; } return ssl.version; } static void parse_session(struct pt_regs *ctx, u16 tls_version) { // Parse a struct sl_session_st pointer and send // data to userspace // TLS information sent to userspace struct TLS_information_t tls_information; __builtin_memset(&tls_information, 0, sizeof(tls_information)); // it makes the eBPF verifier happy! tls_information.tls_version = tls_version; // Get a ssl_st pointer void *ssl_st_ptr = (void *) PT_REGS_PARM1(ctx); // Get a ssl_session_st pointer u64 *ssl_session_st_ptr = (u64 *) (ssl_st_ptr + SSL_SESSION_OFFSET); u64 address; long ret = bpf_probe_read(&address, sizeof(address), ssl_session_st_ptr); if (ret != 0) bpf_trace_printk("parse_session() #1 - bpf_probe_read() failed\n"); // Access the TLS 1.2 master secret void *ms_ptr = (void *) (address + MASTER_SECRET_OFFSET); ret = bpf_probe_read(&tls_information.master_secret, sizeof(tls_information.master_secret), ms_ptr); if (ret != 0) bpf_trace_printk("parse_session() #2 - bpf_probe_read() failed\n"); // Get a ssl_cipher_st pointer void *ssl_cipher_st_ptr = (void *) (address + SSL_CIPHER_OFFSET); ret = bpf_probe_read(&address, sizeof(address), ssl_cipher_st_ptr); if (ret != 0) bpf_trace_printk("parse_session() #3 - bpf_probe_read() failed\n"); // Get the SSL_cipher_st point to the name member ssl_cipher_st_ptr = (void *) (address + 8); ret = bpf_probe_read(&address, sizeof(address), ssl_cipher_st_ptr); if (ret != 0) bpf_trace_printk("parse_session() #4 - bpf_probe_read() failed\n"); // Access the TLS ciphersuite void *cs_ptr = (void *) address; ret = bpf_probe_read(&tls_information.ciphersuite, sizeof(tls_information.ciphersuite), cs_ptr); if (ret != 0) bpf_trace_printk("parse_session() #5 - bpf_probe_read() failed\n"); // Retrieve the Client Random void* client_hello_ptr = (void *) (ssl_st_ptr + CLIENT_HELLO_OFFSET); ret = bpf_probe_read(&address, sizeof(address), client_hello_ptr); if (ret != 0) bpf_trace_printk("parse_session() #6 - bpf_probe_read() failed\n"); u8 client_random[CLIENT_RANDOM_MAX_LEN + CLIENT_RANDOM_OFFSET]; ret = bpf_probe_read(client_random, sizeof(client_random), client_hello_ptr); if (ret != 0) bpf_trace_printk("parse_session() #7 - bpf_probe_read() failed\n"); ret = bpf_probe_read(&tls_information.client_random, sizeof(tls_information.client_random), client_random + CLIENT_RANDOM_OFFSET); if (ret != 0) bpf_trace_printk("parse_session() #8 - bpf_probe_read() failed\n"); u32 pid = bpf_get_current_pid_tgid() & 0xFFFFFFFF; tls_information_cache.update(&pid, &tls_information); } static int SSL_read_write(struct pt_regs *ctx, u16 tls_version, struct SSL_buffer_t *buffer) { // A buffer is needed if (buffer == NULL) return 0; // Retrieve connect() information for PID u32 pid = bpf_get_current_pid_tgid() & 0xFFFFFFFF; struct tls_event_t *event = (struct tls_event_t*) pid_cache.lookup(&pid); if (event == NULL) { //get ppid to check if it is a child of a known process struct task_struct *task; task = (struct task_struct *)bpf_get_current_task(); pid = task->real_parent->tgid; event = (struct tls_event_t*) pid_cache.lookup(&pid); if(event == NULL) return 0; } // Build a new TLS event and fill it struct tls_event_t new_event; bpf_get_current_comm(&new_event.comm, COMM_MAX_LEN); new_event.pid = pid; new_event.port = event->port; new_event.addr = event->addr; new_event.is_read = buffer->is_read; new_event.tls_version = tls_version; long ret = bpf_probe_read(&new_event.message, sizeof(new_event.message), (void*) buffer->ptr); if (ret != 0) { bpf_trace_printk("SSL_read_write() - bpf_probe_read() failed\n"); return 0; } new_event.message_length = buffer->length; // Send the event to userland tls_events.perf_submit(ctx, &new_event, sizeof(new_event)); // Flush the PID cache if (DIRECTIONS) // this will be replaced by a boolean in Python pid_cache.delete(&pid); return 0; } int SSL_read(struct pt_regs *ctx) { // Retrieve the PID u32 pid = bpf_get_current_pid_tgid() & 0xFFFFFFFF; // Store a SSL read buffer information in the cache struct SSL_buffer_t buffer; __builtin_memset(&buffer, 0, sizeof(buffer)); buffer.ptr = PT_REGS_PARM2(ctx); // Get TLS version void *ssl_st_ptr = (void *) PT_REGS_PARM1(ctx); buffer.tls_version = get_tls_version(ssl_st_ptr); SSL_read_buffers.update(&pid, &buffer); return 0; } int SSL_read_ret(struct pt_regs *ctx) { // Discard if nothing was received int buffer_length = PT_REGS_RC(ctx); if (buffer_length == -1) return 0; // Retrieve SSL read buffers information for PID u32 pid = bpf_get_current_pid_tgid() & 0xFFFFFFFF; struct SSL_buffer_t *buffer = (struct SSL_buffer_t*) SSL_read_buffers.lookup(&pid); if (buffer == NULL) return 0; // Add buffer information buffer->length = buffer_length; buffer->is_read = 1; long ret = SSL_read_write(ctx, buffer->tls_version, buffer); SSL_read_buffers.delete(&pid); return ret; } int SSL_write(struct pt_regs *ctx) { // Retrieve the buffer information struct SSL_buffer_t buffer; buffer.ptr = PT_REGS_PARM2(ctx); buffer.length = PT_REGS_PARM3(ctx); buffer.is_read = 0; // Get TLS version void *ssl_st_ptr = (void *) PT_REGS_PARM1(ctx); u16 tls_version = get_tls_version(ssl_st_ptr); parse_session(ctx, tls_version); return SSL_read_write(ctx, tls_version, &buffer); } ================================================ FILE: peetch/globals.py ================================================ # SPDX-License-Identifier: GPL-2.0+ # Guillaume Valadon BPF_HANDLER = None BPF_TLS_HANDLER = None PACKETS_CAPTURED = [] TLS_INFORMATION = {} ================================================ FILE: peetch/proxy.py ================================================ # SPDX-License-Identifier: GPL-2.0+ # Guillaume Valadon import asyncio import binascii import ctypes as ct import socket import struct import sys import time from scapy.all import sniff, IP, TCP, conf import peetch.globals def retrieve_client_information(bpf_handler, port_src): """ Get client information from eBPF maps """ process_name, process_pid, ip_dst, port_dst = [None] * 4 bpf_map_destination_cache = bpf_handler["destination_cache"] destination_key_to_delete = None for destination_key, destination_data in bpf_map_destination_cache.items_lookup_batch(): # noqa: E501 process_pid = destination_data.pid process_name = destination_data.name.decode("ascii", "replace") # Retrieve destination IP and port address_packed = struct.pack("I", destination_data.ip) ip_dst = socket.inet_ntop(socket.AF_INET, address_packed) port_dst = socket.ntohs(destination_data.port) if socket.ntohs(destination_key.value) == port_src: ct_array = ct.c_uint16 * 1 destination_key_to_delete = ct_array(destination_key) break if destination_key_to_delete: bpf_map_destination_cache.items_delete_batch(destination_key_to_delete) return process_name, process_pid, ip_dst, port_dst def retrieve_tls_information(bpf_handler, process_pid): """ Get TLS information from eBPF maps """ tls_version, ciphersuite, client_random, master_secret = [None] * 4 retries = 5 pid_to_delete = None bpf_map_tls_information = bpf_handler["tls_information_cache"] while pid_to_delete is None and retries: retries -= 1 for pid, tls_info in bpf_map_tls_information.items_lookup_batch(): if pid.value == process_pid: ciphersuite = tls_info.ciphersuite.decode("ascii", "ignore") master_secret = binascii.hexlify(tls_info.master_secret) master_secret = master_secret.decode("ascii", "ignore") client_random = binascii.hexlify(tls_info.client_random) client_random = client_random.decode("ascii", "ignore") tls_version = (tls_info.tls_version & 0xF) - 1 if len(ciphersuite): ct_array = ct.c_uint * 1 pid_to_delete = ct_array(pid) break #time.sleep(0.005) # Delete pid from the eBPF map if pid_to_delete: bpf_map_tls_information.items_delete_batch(pid_to_delete) return tls_version, ciphersuite, client_random, master_secret async def dots(): """ print dots """ while True: await asyncio.sleep(0.5) print(".", end="", flush=True) def decrypt_messages(tls_information, packets): """ Decrypt and display messages """ tls_version = tls_information.get("version", sys.maxsize) if tls_version < 3: for p in sniff(offline=packets): if TLSApplicationData in p: # noqa: F821 print() p[TLSApplicationData].show() # noqa: F821 async def handle_client(local_reader, local_writer): """ Proxy a new client connection """ # Retrieve source IP and port used to connect to the proxy ip_src, port_src = local_reader._transport.get_extra_info("peername") # Retrieve process information, and destination IP and port tmp = retrieve_client_information(peetch.globals.BPF_HANDLER, port_src) process_name, process_pid, ip_dst, port_dst = tmp if process_name is None: print("[!] Did not find the real destination") local_writer.close() return print("", flush=True) print(f"\r[+] Intercepting traffic from {process_name}/{process_pid}", end="") # noqa: E501 print(f" to {ip_dst}/{port_dst} via {ip_src}/{port_src}") try: # Connect to the real destination and copy data between sockets tmp = await asyncio.open_connection(ip_dst, port_dst) remote_reader, remote_writer = tmp pipe1 = pipe(local_reader, remote_writer, process_pid, "-->", ip_src, ip_dst, port_src, port_dst) pipe2 = pipe(remote_reader, local_writer, process_pid, "<--", ip_dst, ip_src, port_dst, port_src) await asyncio.gather(pipe1, pipe2) # Decrypt and display TLS messages decrypt_messages(peetch.globals.TLS_INFORMATION, peetch.globals.PACKETS_CAPTURED) # Reset global variables conf.tls_nss_keys = {} peetch.globals.TLS_INFORMATION = {} peetch.globals.PACKETS_CAPTURED = [] except ConnectionResetError as e: print(f" {e}") finally: local_writer.close() async def pipe(reader, writer, pid, direction, ip_src, ip_dst, port_src, port_dst): # noqa: E501 """" Copy data from one socket to another and retrieve TLS information Inspired by https://stackoverflow.com/a/46422554 """ try: while not reader.at_eof(): data = await reader.read(8192) if not len(data): continue # Rebuild the IP packet tls_record = IP(dst=ip_dst, src=ip_src) tls_record /= TCP(dport=port_dst, sport=port_src) tls_record /= TLS(data) # noqa: F821 peetch.globals.PACKETS_CAPTURED += [tls_record] # Display a short summary sprintf_fmt = "%IP.src%:%TCP.sport% > %IP.dst%:%TCP.dport% %IP.proto%" # noqa: E501 summary = tls_record.sprintf(sprintf_fmt) print(f" {direction} {summary}") # Copy data to the other socket writer.write(data) # Get and store TLS information tls_version, ciphersuite, client_random, master_secret = retrieve_tls_information(peetch.globals.BPF_TLS_HANDLER, pid) # noqa: E501 if ciphersuite: if tls_version < 3: client_random_bytes = binascii.unhexlify(client_random) master_secret_bytes = binascii.unhexlify(master_secret) conf.tls_nss_keys = {"CLIENT_RANDOM": {client_random_bytes: master_secret_bytes}} # noqa: E501 peetch.globals.TLS_INFORMATION = {"version": tls_version, "ciphersuite": ciphersuite} # noqa: E501 finally: writer.close() async def tcp_proxy(): """ async TCP proxy """ server = await asyncio.start_server(handle_client, "127.0.0.1", 2807) await server.serve_forever() async def all_tasks(debug): """ all proxy tasks """ tasks = [tcp_proxy()] if debug: tasks += [dots()] await asyncio.gather(*tasks) ================================================ FILE: peetch/utils.py ================================================ # SPDX-License-Identifier: GPL-2.0+ # Guillaume Valadon import ctypes import os import os.path import sys # Identify the library path dirname = os.path.dirname(__file__) UTILS_LIB_PATH = None for root, dirs, files in os.walk(dirname): for file in files: if file.startswith("utils_lib") and file.endswith(".so"): UTILS_LIB_PATH = os.path.join(root, file) break class LIBSSLOffsets(ctypes.Structure): _fields_ = [("ssl_session", ctypes.c_uint64), ("ssl_cipher", ctypes.c_uint64), ("master_secret", ctypes.c_uint64), ("client_hello", ctypes.c_uint64), ("client_random", ctypes.c_uint64)] if UTILS_LIB_PATH: libssl_offset = ctypes.CDLL(UTILS_LIB_PATH) libssl_offset.libssl_offsets.argstypes = [ctypes.c_char_p, ctypes.c_uint16] libssl_offset.libssl_offsets.restype = LIBSSLOffsets def get_offsets(address_ipv4=b"1.1.1.1", port=443): # Retrieve offsets inside SSL structures raw_offsets = libssl_offset.libssl_offsets(address_ipv4, port) return (raw_offsets.ssl_session, raw_offsets.ssl_cipher, raw_offsets.master_secret, raw_offsets.client_hello, raw_offsets.client_random) else: print("ERROR: cannot find the utils_lib dynamic library!", file=sys.stderr) sys.exit(1) if __name__ == "__main__": print(["0x%x" % offset for offset in get_offsets()]) ================================================ FILE: requirements.txt ================================================ scapy @ git+https://github.com/secdev/scapy@master cryptography pyroute2 ================================================ FILE: setup.py ================================================ # SPDX-License-Identifier: GPL-2.0+ # Guillaume Valadon from distutils.core import setup, Extension setup(name="peetch", description="An eBPF playground", author="Guillaume Valadon", author_email="gvaladon@quarkslab.com", version="0.2.0", packages=["peetch"], package_data={"peetch": ["ebpf_programs/peetch_*.c"]}, entry_points={"console_scripts": ["peetch=peetch:main"]}, ext_modules=[Extension("peetch.utils_lib", sources=["peetch/c_utils/libssl.c"], libraries=["ssl"])], )