mtg/example.config.toml

# This is an example of the configuration file for mtg. You actually can
# run mtg with it. It starts a proxy on all interfaces with a secret
# ee367a189aee18fa31c190054efd4a8e9573746f726167652e676f6f676c65617069732e636f6d
#
# It has all possible options with default values. So, a real world
# configuration file should contain only those options you are going to
# use. You do not need to enumerate all of them. In other words, each
# option here has a default value. If you comment a key-value pair, it
# should not make any effect.
#
# stats is the only exception.

# Debug starts application in debug mode. It starts to be quite verbose
# in output. Actually, the idea is that you run it in debug mode only if
# you have any issue.
debug = true

# A secret. Please remember that mtg supports only FakeTLS mode, legacy
# simple and secured mode are prohibited. For you it means that secret
# should either be base64-encoded or starts with ee.
secret = "ee367a189aee18fa31c190054efd4a8e9573746f726167652e676f6f676c65617069732e636f6d"

# Host:port pair to run proxy on.
bind-to = "0.0.0.0:3128"

# This defines what types of traffic mtg listens to. If you are not sure,
# then definitely keep it disable. Enable it only and only if incoming traffic
# is coming from some sort of load-balancer like HAProxy or ELB.
# https://www.haproxy.org/download/2.3/doc/proxy-protocol.txt
#
# mtg uses a library that supports v1 and v2 versions of ProxyProtocol.
# default value is false.
# proxy-protocol-listener = false

# Defines how many concurrent connections are allowed to this proxy.
# All other incoming connections are going to be dropped.
concurrency = 8192

# Sometimes you want to enforce mtg to use some types of
# IP connectivity to Telegram. We have 4 modes:
#   - prefer-ipv6:
#     We can use both ipv4 and ipv6 but ipv6 has a preference
#   - prefer-ipv4:
#     We can use both ipv4 and ipv6 but ipv4 has a preference
#   - only-ipv6:
#     Only ipv6 connectivity is used
#   - only-ipv4:
#     Only ipv4 connectivity is used
prefer-ip = "prefer-ipv6"

# If this setting is set, then mtg will try to get proxy updates from Telegram
# Usually this is completely fine to have it disabled, because mtg has a list
# of some core proxies hardcoded.
auto-update = false

# FakeTLS uses domain fronting protection. So it needs to know a port to
# access.
#
# Deprecated: use [domain-fronting] configuration block. If relevant option
# is defined there, this one would be ignored.
# domain-fronting-port = 443

# By default, mtg resolves the fronting hostname (from the secret) via DNS
# to establish a TCP connection. If DNS resolution of that hostname is blocked,
# you can specify an IP address to connect to directly. The hostname is still
# used for SNI in the TLS handshake.
#
# default value is not set (DNS resolution is used).
#
# Deprecated: use [domain-fronting] configuration block. If relevant option
# is defined there, this one would be ignored.
# domain-fronting-ip = "10.0.0.10"

# This makes a communication between both fronting website and mtg to use
# proxy protocol.
#
# Deprecated: use [domain-fronting] configuration block. If relevant option
# is defined there, this one would be ignored.
# domain-fronting-proxy-protocol = false

# FakeTLS can compare timestamps to prevent probes. Each message has
# encrypted timestamp. So, mtg can compare this timestamp and decide if
# we need to proceed with connection or not.
#
# Sometimes time can be skewed so we accept all messages within a
# time range of this parameter.
tolerate-time-skewness = "5s"

# Telegram has a concept of DC. You can think about DC as a number of a cluster
# with a certain purpose. Some clusters serve media, some - messages, some rule
# channels and so on. But sometimes unknown DC number is requested by client.
# It could be a bug or some global reconfiguration of the Telegram.
#
# By default, proxy rejects such requests. But it is also possible to fallback
# this request to any DC. Telegram works in a way that any DC is able to serve
# any request but sacrificing a latency.
#
# If this setting is disabled (default), mtg will reject a connection.
# Otherwise, chose a new DC.
allow-fallback-on-unknown-dc = false

# This section is relevant to communication with fronting domain. Usually
# you do not need to setup anything here but there are plenty of cases, especially
# if you put mtg behind load balancer, when some specific configuration is
# required.
[domain-fronting]
# By default, mtg resolves the fronting hostname (from the secret) via DNS
# to establish a TCP connection. If DNS resolution of that hostname is blocked,
# you can specify an IP address to connect to directly. The hostname is still
# used for SNI in the TLS handshake.
#
# default value is not set (DNS resolution is used).
# ip = "10.10.10.11"

# FakeTLS uses domain fronting protection. So it needs to know a port to
# access. Default value is 443
# port = 443

# This makes a communication between both fronting website and mtg to use
# proxy protocol.
# proxy-protocol = false

# network defines different network-related settings
[network]
# please be aware that mtg needs to do some external requests. For
# example, if you do not pass public ips, it will request your public ip
# address from some external service.
#
# As for 2.0, if you set a public-ip on your own, mtg won't issue any
# network requests except of those required for Telegram.
#
# so, in order of doing them, it needs to do DNS lookup. mtg ignores DNS
# resolver of the operating system and uses DOH instead. This is a host
# it has to access.
#
# By default we use Cloudflare.
#
# DEPRECATED option:
#  If dns option is specified, it will be used instead. No default is defined
#  anymore. But if you set this option, this is literally the same providing
#  https:// URL to `dns`.
#
#  In other words:
#
#    doh-ip = "1.1.1.1"
#
# is literally the same as
#
#    dns = "https://1.1.1.1"
# doh-ip = "1.1.1.1"

# Starting from mtg v2.1.12 we have changed a configuration for DNS. Now it
# supports DNS-over-HTTPS, DNS-over-TLS, custom UDP resolver and system
# resolver.
#
# Here is how to define DNS-over-HTTPS:
#  - https://1.1.1.1
#  - https://1.1.1.1/dns-query
#  - https://cloudflare-dns.com/dns-query
#  - https://cloudflare-dns.com
#
# Here is how to define DNS-over-TLS:
#  - tls://1.1.1.1
#  - tls://cloudflare-dns.com
#
# Here is how to define a custom UDP resolver (we support only IPs here)
#  - 1.1.1.1
#  - udp://1.1.1.1
#
# If you set it to empty string, default resolver will be used.
# But please comment out doh-ip
dns = "https://1.1.1.1"

# mtg can work via proxies (for now, we support only socks5). Proxy
# configuration is done via list. So, you can specify many proxies
# there.
#
# Actually, if you supply an empty list, then no proxies are going to be
# used. If you supply a single proxy, then mtg will use it exclusively.
# If you supply >= 2, then mtg will load balance between them.
#
# If you add an empty string here, this is an equivalent of 'plain network',
# with no proxy usage.
#
# Proxy configuration is done via ordinary URI schema:
#
#     socks5://user:password@host:port
#
# Only socks5 proxy is used. user/password is optional. As you can
# see, you can specify some parameters in GET query. These parameters
# configure circuit breaker.
proxies = [
    # "socks5://user:password@host:port"
]

# network timeouts define different settings for timeouts. tcp timeout
# define a global timeout on establishing of network connections. idle
# means a timeout on pumping data between sockset when nothing is
# happening.
#
# please be noticed that handshakes have no timeouts intentionally. You can
# find a reasoning here:
# https://www.ndss-symposium.org/wp-content/uploads/2020/02/23087-paper.pdf
[network.timeout]
tcp = "5s"
http = "10s"
idle = "1m"

# mtg has to mimic real websites. It does not mean domain fronting, it also
# means that traffic characteristics should be similar to real world traffic.
# websites and applications behave differently, their traffic patterns are also
# different. Applications do bursts of RPC-style messages (or JSON communication,
# does not really matter), while websites pump heavy content in HTTP2 streams
#
# It means that statistically there is a different between traffic shape:
# TLS packet sizes are different, delays between packets are also different.
# In order to avoid censorship detection based on these patterns, there is a
# mtg subsystem called "Doppelganger" that aims to mimic website statistics
# as close as it could.
#
# It does that by 2 ideas:
#   1. Delays between TLS packets are not constant. There are many factors
#      that come in play. Application should generate some response, it could
#      send some headers first and stream content with chunked encoding. So
#      some first packets could come as soon as possible, with some delays
#      after first ones. Such phenomenon is described by different statistic
#      distribution. There are 2 distribution that describe it: lognormal
#      distribution and Weibul distribution. Lognormal is all about steady streams
#      of heavy content like a video. Weibul is great about short bursts like
#      user who requested a static page an a couple of images.
#
#      mtg tries to adapt Weibul distribution. It comes with some sensible
#      defaults that were taken from ok.ru. But when you use domain fronting,
#      it always make sense to take statistics from that website. You can specify
#      some urls here. mtg will crawl them from time to time, accumulate time
#      series and approximates parameters for Weibul.
#   2. TLS record sizes are not random.
#      https://blog.cloudflare.com/optimizing-tls-over-tcp-to-reduce-latency/
#      https://aws.github.io/s2n-tls/usage-guide/ch08-record-sizes.html
#
#      The idea is that huge TLS records could negatively affect performance.
#      You cannot simply decrypt a part of the packet, you need to wait it
#      whole, and huge packets could involve several RTTs if you do not use
#      any specific software that treat TLS in a very special way. So
#      servers start with small packets, usually around MTU, and ramp up
#      later. This optimizes a time-to-first byte so web browsers start to
#      render early.
#
#      mtg uses the same technique as was introduced by Cloudflare in their
#      patches to nginx 10 years ago:
#      https://github.com/cloudflare/sslconfig/blob/master/patches/nginx__dynamic_tls_records.patch
[defense.doppelganger]
# This is a list of URLs that would be crawled by mtg to approximate delay
# statistics. They MUST be HTTPS urls.
#
# You can come to the website and collect different URLs, with light and
# heavy content. We recommend to search for CDNs.
urls = [
    # "https://st-ok.cdn-vk.ru/res/react/vendor/clsx-2.1.1-amd.js"
]
# A collection is done in raids. Each raid makes this number of requests to
# each URL in this list. Do not use a huge number, 10 is probably ok.
repeats-per-raid = 10
# This is a duration between each raid. It makes no sense to have a small number
# here as you would start to make a noticeable activity. Usually traffic patterns
# do not change a lot, so do not expect different results if you request
# each 10 minutes.
raid-each = "6h"

# Some countries do active probing on Telegram connections. This technique
# allows to protect from such effort.
#
# mtg has a cache of some connection fingerprints. Actually, first bytes
# of each connection. So, it stores them in some in-memory LRU+TTL cache.
# You can configure this cache here.
[defense.anti-replay]
# You can enable/disable this feature.
enabled = true
# max size of such a cache. Please be aware that this number is
# approximate we try hard to store data quite dense but it is possible
# that we can go over this limit for 10-20% under some conditions and
# architectures.
max-size = "1mib"
# we use stable bloom filters for anti-replay cache. This helps
# to maintain a desired error ratio.
error-rate = 0.001

# You can protect proxies by using different blocklists. If client has
# ip from the given range, we do not try to do a proper handshake. We
# actually route it to fronting domain. So, this client will never ever
# have a chance to use mtg to access Telegram.
#
# Please remember that blocklists are initialized in async way. So,
# when you start a proxy, blocklists are empty, they are populated and
# processed in backgrounds. An error in any URL is ignored.
[defense.blocklist]
# You can enable/disable this feature.
enabled = true
# This is a limiter for concurrency. In order to protect website
# from overloading, we download files in this number of threads.
download-concurrency = 2
# A list of URLs in FireHOL format (https://iplists.firehol.org/)
# You can provider links here (starts with https:// or http://) or
# path to a local file, but in this case it should be absolute.
urls = [
    "https://iplists.firehol.org/files/firehol_level1.netset",
    # "/local.file"
]
# How often do we need to update a blocklist set.
update-each = "24h"

# Allowlist is an opposite to a blocklist. Only those IPs that are coming from
# subnets defined in these lists are allowed. All others will be rejected.
#
# If this feature is disabled, then there won't be any check performed by this
# validator. It is possible to combine both blocklist and whitelist.
[defense.allowlist]
# You can enable/disable this feature.
enabled = false
# This is a limiter for concurrency. In order to protect website
# from overloading, we download files in this number of threads.
download-concurrency = 2
# A list of URLs in FireHOL format (https://iplists.firehol.org/)
# You can provider links here (starts with https:// or http://) or
# path to a local file, but in this case it should be absolute.
urls = [
    # "https://iplists.firehol.org/files/firehol_level1.netset",
    # "/local.file"

]
update-each = "24h"

# statsd statistics integration.
[stats.statsd]
# enabled/disabled
enabled = false
# host:port for UDP endpoint of statsd
address = "127.0.0.1:8888"
# prefix of metric for statsd
metric-prefix = "mtg"
# tag format to use
# supported values are 'datadog', 'influxdb' and 'graphite'
# default format is graphite.
tag-format = "datadog"

# prometheus metrics integration.
[stats.prometheus]
# enabled/disabled
enabled = true
# host:port where to start http server for endpoint
bind-to = "127.0.0.1:3129"
# prefix of http path
http-path = "/"
# prefix for metrics for prometheus
metric-prefix = "mtg"