Ya comentamos con anterioridad la importancia de cifrar las conexiones DNS por motivos de seguridad con DNSCrypt-proxy, tanto en la entrada de Debian 10 como en la de Debian 9, pero no llegamos a comentar como actualizar dicho software. Y eso es lo que voy a detallar a continuación ofreciendo y potenciando algunas variables que se han incorporado en las últimas versiones.

Procedimiento actualización

El apartado interesante es saber de que versión estamos partiendo para actualizar, nos abrimos una ventana de terminal y ejecutamos:

pi@overclock:~$ /opt/dnscrypt-proxy/./dnscrypt-proxy -version
2.0.25
pi@overclock:~$

Buenos ya sabemos que partimos de la versión 2.0.25. Ahora lo que debemos de hacer es ingresar en el repositorio del proyecto para conocer los cambios y últimas versiones lanzadas.

A continuación elegimos el paquete según nuestra plataforma y Sistema Operativo, en el caso que estamos viendo de nuestro servidor (Linux x86 64bits).

Abrimos una sesión de terminal en nuestro server y nos dirigimos a nuestra carpeta de usuario para descargar el paquete elegido:

cd && wget https://github.com/DNSCrypt/dnscrypt-proxy/releases/download/2.0.31/dnscrypt-proxy-linux_x86_64-2.0.31.tar.gz

Ahora descomprimimos el paquete:

tar -xf dnscrypt-proxy-linux_x86_64-2.0.31.tar.gz && mv dnscrypt-proxy-linux_x86_64-2.0.31.tar.gz ~/linux-x86_64 && cd linux-x86_64

Entramos a configurar el programa:

nano dnscrypt-proxy.toml

Adjunto mi fichero de configuración (tomado de base example-dnscrypt-proxy.toml), el cual he modificado el puerto de gestión de la dirección local, habilitado DNSSEC, dnscrypt_ephemeral_keys, tls_disable_session_tickets & anonymized_dns:


##############################################
#                                            #
#        dnscrypt-proxy configuration        #
#                                            #
##############################################

## This is an example configuration file.
## You should adjust it to your needs, and save it as "dnscrypt-proxy.toml"
##
## Online documentation is available here: https://dnscrypt.info/doc



##################################
#         Global settings        #
##################################

## List of servers to use
##
## Servers from the "public-resolvers" source (see down below) can
## be viewed here: https://dnscrypt.info/public-servers
##
## If this line is commented, all registered servers matching the require_* filters
## will be used.
##
## The proxy will automatically pick the fastest, working servers from the list.
## Remove the leading # first to enable this; lines starting with # are ignored.

# server_names = ['scaleway-fr', 'google', 'yandex', 'cloudflare']


## List of local addresses and ports to listen to. Can be IPv4 and/or IPv6.

listen_addresses = ['127.0.0.1:40', '[::1]:40']


## Maximum number of simultaneous client connections to accept

max_clients = 250


## Switch to a different system user after listening sockets have been created.
## Note (1): this feature is currently unsupported on Windows.
## Note (2): this feature is not compatible with systemd socket activation.
## Note (3): when using -pidfile, the PID file directory must be writable by the new user

# user_name = 'nobody'


## Require servers (from static + remote sources) to satisfy specific properties

# Use servers reachable over IPv4
ipv4_servers = true

# Use servers reachable over IPv6 -- Do not enable if you don't have IPv6 connectivity
ipv6_servers = false

# Use servers implementing the DNSCrypt protocol
dnscrypt_servers = true

# Use servers implementing the DNS-over-HTTPS protocol
doh_servers = true


## Require servers defined by remote sources to satisfy specific properties

# Server must support DNS security extensions (DNSSEC)
require_dnssec = true

# Server must not log user queries (declarative)
require_nolog = true

# Server must not enforce its own blacklist (for parental control, ads blocking...)
require_nofilter = true

# Server names to avoid even if they match all criteria
disabled_server_names = []


## Always use TCP to connect to upstream servers.
## This can be useful if you need to route everything through Tor.
## Otherwise, leave this to `false`, as it doesn't improve security
## (dnscrypt-proxy will always encrypt everything even using UDP), and can
## only increase latency.

force_tcp = false


## SOCKS proxy
## Uncomment the following line to route all TCP connections to a local Tor node
## Tor doesn't support UDP, so set `force_tcp` to `true` as well.

# proxy = 'socks5://127.0.0.1:9050'


## HTTP/HTTPS proxy
## Only for DoH servers

# http_proxy = 'http://127.0.0.1:8888'


## How long a DNS query will wait for a response, in milliseconds.
## If you have a network with *a lot* of latency, you may need to
## increase this. Startup may be slower if you do so.
## Don't increase it too much. 10000 is the highest reasonable value.

timeout = 5000


## Keepalive for HTTP (HTTPS, HTTP/2) queries, in seconds

keepalive = 30


## Response for blocked queries.  Options are `refused`, `hinfo` (default) or
## an IP response.  To give an IP response, use the format `a:<IPv4>,aaaa:<IPv6>`.
## Using the `hinfo` option means that some responses will be lies.
## Unfortunately, the `hinfo` option appears to be required for Android 8+

# blocked_query_response = 'refused'


## Load-balancing strategy: 'p2' (default), 'ph', 'first' or 'random'

# lb_strategy = 'p2'

## Set to `true` to constantly try to estimate the latency of all the resolvers
## and adjust the load-balancing parameters accordingly, or to `false` to disable.

# lb_estimator = true


## Log level (0-6, default: 2 - 0 is very verbose, 6 only contains fatal errors)

# log_level = 2


## log file for the application

# log_file = 'dnscrypt-proxy.log'


## Use the system logger (syslog on Unix, Event Log on Windows)

# use_syslog = true


## Delay, in minutes, after which certificates are reloaded

cert_refresh_delay = 240


## DNSCrypt: Create a new, unique key for every single DNS query
## This may improve privacy but can also have a significant impact on CPU usage
## Only enable if you don't have a lot of network load

dnscrypt_ephemeral_keys = true


## DoH: Disable TLS session tickets - increases privacy but also latency

tls_disable_session_tickets = true


## DoH: Use a specific cipher suite instead of the server preference
## 49199 = TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
## 49195 = TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
## 52392 = TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305
## 52393 = TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305
##  4865 = TLS_AES_128_GCM_SHA256
##  4867 = TLS_CHACHA20_POLY1305_SHA256
##
## On non-Intel CPUs such as MIPS routers and ARM systems (Android, Raspberry Pi...),
## the following suite improves performance.
## This may also help on Intel CPUs running 32-bit operating systems.
##
## Keep tls_cipher_suite empty if you have issues fetching sources or
## connecting to some DoH servers. Google and Cloudflare are fine with it.

# tls_cipher_suite = [52392, 49199]


## Fallback resolver
## This is a normal, non-encrypted DNS resolver, that will be only used
## for one-shot queries when retrieving the initial resolvers list, and
## only if the system DNS configuration doesn't work.
## No user application queries will ever be leaked through this resolver,
## and it will not be used after IP addresses of resolvers URLs have been found.
## It will never be used if lists have already been cached, and if stamps
## don't include host names without IP addresses.
## It will not be used if the configured system DNS works.
## A resolver supporting DNSSEC is recommended. This may become mandatory.
##
## People in China may need to use 114.114.114.114:53 here.
## Other popular options include 8.8.8.8 and 1.1.1.1.

fallback_resolver = '9.9.9.9:53'


## Never let dnscrypt-proxy try to use the system DNS settings;
## unconditionally use the fallback resolver.

ignore_system_dns = false


## Maximum time (in seconds) to wait for network connectivity before
## initializing the proxy.
## Useful if the proxy is automatically started at boot, and network
## connectivity is not guaranteed to be immediately available.
## Use 0 to not test for connectivity at all (not recommended),
## and -1 to wait as much as possible.

netprobe_timeout = 60

## Address and port to try initializing a connection to, just to check
## if the network is up. It can be any address and any port, even if
## there is nothing answering these on the other side. Just don't use
## a local address, as the goal is to check for Internet connectivity.
## On Windows, a datagram with a single, nul byte will be sent, only
## when the system starts.
## On other operating systems, the connection will be initialized
## but nothing will be sent at all.

netprobe_address = '9.9.9.9:53'


## Offline mode - Do not use any remote encrypted servers.
## The proxy will remain fully functional to respond to queries that
## plugins can handle directly (forwarding, cloaking, ...)

# offline_mode = false


## Additional data to attach to outgoing queries.
## These strings will be added as TXT records to queries.
## Do not use, except on servers explicitly asking for extra data
## to be present.

# query_meta = ["key1:value1", "key2:value2", "key3:value3"]


## Automatic log files rotation

# Maximum log files size in MB - Set to 0 for unlimited.
log_files_max_size = 10

# How long to keep backup files, in days
log_files_max_age = 7

# Maximum log files backups to keep (or 0 to keep all backups)
log_files_max_backups = 1



#########################
#        Filters        #
#########################

## Immediately respond to IPv6-related queries with an empty response
## This makes things faster when there is no IPv6 connectivity, but can
## also cause reliability issues with some stub resolvers.
## Do not enable if you added a validating resolver such as dnsmasq in front
## of the proxy.

block_ipv6 = false


## TTL for synthetic responses sent when a request has been blocked (due to
## IPv6 or blacklists).

reject_ttl = 600



##################################################################################
#        Route queries for specific domains to a dedicated set of servers        #
##################################################################################

## Example map entries (one entry per line):
## example.com 9.9.9.9
## example.net 9.9.9.9,8.8.8.8,1.1.1.1

# forwarding_rules = 'forwarding-rules.txt'



###############################
#        Cloaking rules       #
###############################

## Cloaking returns a predefined address for a specific name.
## In addition to acting as a HOSTS file, it can also return the IP address
## of a different name. It will also do CNAME flattening.
##
## Example map entries (one entry per line)
## example.com     10.1.1.1
## www.google.com  forcesafesearch.google.com

# cloaking_rules = 'cloaking-rules.txt'

## TTL used when serving entries in cloaking-rules.txt

# cloak_ttl = 600


###########################
#        DNS cache        #
###########################

## Enable a DNS cache to reduce latency and outgoing traffic

cache = true


## Cache size

cache_size = 512


## Minimum TTL for cached entries

cache_min_ttl = 600


## Maximum TTL for cached entries

cache_max_ttl = 86400


## Minimum TTL for negatively cached entries

cache_neg_min_ttl = 60


## Maximum TTL for negatively cached entries

cache_neg_max_ttl = 600



###############################
#        Query logging        #
###############################

## Log client queries to a file

[query_log]

  ## Path to the query log file (absolute, or relative to the same directory as the executable file)
  ## Can be /dev/stdout to log to the standard output (and set log_files_max_size to 0)

  # file = 'query.log'


  ## Query log format (currently supported: tsv and ltsv)

  format = 'tsv'


  ## Do not log these query types, to reduce verbosity. Keep empty to log everything.

  # ignored_qtypes = ['DNSKEY', 'NS']



############################################
#        Suspicious queries logging        #
############################################

## Log queries for nonexistent zones
## These queries can reveal the presence of malware, broken/obsolete applications,
## and devices signaling their presence to 3rd parties.

[nx_log]

  ## Path to the query log file (absolute, or relative to the same directory as the executable file)

  # file = 'nx.log'


  ## Query log format (currently supported: tsv and ltsv)

  format = 'tsv'



######################################################
#        Pattern-based blocking (blacklists)        #
######################################################

## Blacklists are made of one pattern per line. Example of valid patterns:
##
##   example.com
##   =example.com
##   *sex*
##   ads.*
##   ads*.example.*
##   ads*.example[0-9]*.com
##
## Example blacklist files can be found at https://download.dnscrypt.info/blacklists/
## A script to build blacklists from public feeds can be found in the
## `utils/generate-domains-blacklists` directory of the dnscrypt-proxy source code.

[blacklist]

  ## Path to the file of blocking rules (absolute, or relative to the same directory as the executable file)

  # blacklist_file = 'blacklist.txt'


  ## Optional path to a file logging blocked queries

  # log_file = 'blocked.log'


  ## Optional log format: tsv or ltsv (default: tsv)

  # log_format = 'tsv'



###########################################################
#        Pattern-based IP blocking (IP blacklists)        #
###########################################################

## IP blacklists are made of one pattern per line. Example of valid patterns:
##
##   127.*
##   fe80:abcd:*
##   192.168.1.4

[ip_blacklist]

  ## Path to the file of blocking rules (absolute, or relative to the same directory as the executable file)

  # blacklist_file = 'ip-blacklist.txt'


  ## Optional path to a file logging blocked queries

  # log_file = 'ip-blocked.log'


  ## Optional log format: tsv or ltsv (default: tsv)

  # log_format = 'tsv'



######################################################
#   Pattern-based whitelisting (blacklists bypass)   #
######################################################

## Whitelists support the same patterns as blacklists
## If a name matches a whitelist entry, the corresponding session
## will bypass names and IP filters.
##
## Time-based rules are also supported to make some websites only accessible at specific times of the day.

[whitelist]

  ## Path to the file of whitelisting rules (absolute, or relative to the same directory as the executable file)

  # whitelist_file = 'whitelist.txt'


  ## Optional path to a file logging whitelisted queries

  # log_file = 'whitelisted.log'


  ## Optional log format: tsv or ltsv (default: tsv)

  # log_format = 'tsv'



##########################################
#        Time access restrictions        #
##########################################

## One or more weekly schedules can be defined here.
## Patterns in the name-based blocklist can optionally be followed with @schedule_name
## to apply the pattern 'schedule_name' only when it matches a time range of that schedule.
##
## For example, the following rule in a blacklist file:
## *.youtube.* @time-to-sleep
## would block access to YouTube only during the days, and period of the days
## define by the 'time-to-sleep' schedule.
##
## {after='21:00', before= '7:00'} matches 0:00-7:00 and 21:00-0:00
## {after= '9:00', before='18:00'} matches 9:00-18:00

[schedules]

  # [schedules.'time-to-sleep']
  # mon = [{after='21:00', before='7:00'}]
  # tue = [{after='21:00', before='7:00'}]
  # wed = [{after='21:00', before='7:00'}]
  # thu = [{after='21:00', before='7:00'}]
  # fri = [{after='23:00', before='7:00'}]
  # sat = [{after='23:00', before='7:00'}]
  # sun = [{after='21:00', before='7:00'}]

  # [schedules.'work']
  # mon = [{after='9:00', before='18:00'}]
  # tue = [{after='9:00', before='18:00'}]
  # wed = [{after='9:00', before='18:00'}]
  # thu = [{after='9:00', before='18:00'}]
  # fri = [{after='9:00', before='17:00'}]



#########################
#        Servers        #
#########################

## Remote lists of available servers
## Multiple sources can be used simultaneously, but every source
## requires a dedicated cache file.
##
## Refer to the documentation for URLs of public sources.
##
## A prefix can be prepended to server names in order to
## avoid collisions if different sources share the same for
## different servers. In that case, names listed in `server_names`
## must include the prefixes.
##
## If the `urls` property is missing, cache files and valid signatures
## must be already present; This doesn't prevent these cache files from
## expiring after `refresh_delay` hours.

[sources]

  ## An example of a remote source from https://github.com/DNSCrypt/dnscrypt-resolvers

  [sources.'public-resolvers']
  urls = ['https://raw.githubusercontent.com/DNSCrypt/dnscrypt-resolvers/master/v2/public-resolvers.md', 'https://download.dnscrypt.info/resolvers-list/v2/public-resolvers.md']
  cache_file = 'public-resolvers.md'
  minisign_key = 'RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3'
  prefix = ''

  ## Anonymized DNS relays

  [sources.'relays']
  urls = ['https://github.com/DNSCrypt/dnscrypt-resolvers/raw/master/v2/relays.md', 'https://download.dnscrypt.info/resolvers-list/v2/relays.md']
  cache_file = 'relays.md'
  minisign_key = 'RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3'
  refresh_delay = 72
  prefix = ''

  ## Quad9 over DNSCrypt - https://quad9.net/

  # [sources.quad9-resolvers]
  # urls = ['https://www.quad9.net/quad9-resolvers.md']
  # minisign_key = 'RWQBphd2+f6eiAqBsvDZEBXBGHQBJfeG6G+wJPPKxCZMoEQYpmoysKUN'
  # cache_file = 'quad9-resolvers.md'
  # prefix = 'quad9-'

  ## Another example source, with resolvers censoring some websites not appropriate for children
  ## This is a subset of the `public-resolvers` list, so enabling both is useless

  #  [sources.'parental-control']
  #  urls = ['https://raw.githubusercontent.com/DNSCrypt/dnscrypt-resolvers/master/v2/parental-control.md', 'https://download.dnscrypt.info/resolvers-list/v2/parental-control.md']
  #  cache_file = 'parental-control.md'
  #  minisign_key = 'RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3'


################################
#        Anonymized DNS        #
################################

[anonymized_dns]

## Routes are indirect ways to reach DNSCrypt servers.
##
## A route maps a server name ("server_name") to one or more relays that will be
## used to connect to that server.
##
## A relay can be specified as a DNS Stamp (either a relay stamp, or a
## DNSCrypt stamp), an IP:port, a hostname:port, or a server name.
##
## The following example routes "example-server-1" via `anon-example-1` or `anon-example-2``,
## and "example-server-2" via the relay whose relay DNS stamp
## is "sdns://gRIxMzcuNzQuMjIzLjIzNDo0NDM".
##
## !!! THESE ARE JUST EXAMPLES !!!
##
## Review the list of available relays from the "relays.md` file, and, for each
## server you want to use, define the relays you want connections to go through.
##
## Carefully choose relays and servers so that the are run by different entities.
##
## "server_name" can also be set to "*" to define a default route, but this is not
## recommended. if you do so, keep "server_names" short and distinct from relays.

routes = [
    { server_name='*', via=['sdns://gRMxNjMuMTcyLjE4MC4xMjU6NDQz', 'sdns://gRIxMzcuNzQuMjIzLjIzNDo0NDM', 'sdns://gQ84My43Ny44NS43Ojg0NDM', 'sdns://gRE1MS4xNS4xMDYuMTc2OjQ0Mw'] }
]


## Optional, local, static list of additional servers
## Mostly useful for testing your own servers.

[static]

  # [static.'myserver']
  # stamp = 'sdns:AQcAAAAAAAAAAAAQMi5kbnNjcnlwdC1jZXJ0Lg'

Guardamos los cambios (Ctrl+O), salimos del editor de texto (Ctrl+X) y debemos de parar el servicio en ejecución:

sudo systemctl stop dnscrypt-proxy

Borramos la anterior base, copiamos la nueva y arrancamos el programa:

sudo rm /opt/dnscrypt-proxy/* && sudo cp ~/linux-x86_64/* /opt/dnscrypt-proxy && sudo systemctl start dnscrypt-proxy && sudo rm -rf ~/linux-x86_64

Podemos chequear estado de ejecución:

pi@overclock:~$ sudo systemctl status dnscrypt-proxy
● dnscrypt-proxy.service - Encrypted/authenticated DNS proxy
   Loaded: loaded (/etc/systemd/system/dnscrypt-proxy.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2019-10-31 11:35:02 CET; 6h ago
 Main PID: 9031 (dnscrypt-proxy)
    Tasks: 21 (limit: 4915)
   Memory: 28.1M
      CPU: 17.050s
   CGroup: /system.slice/dnscrypt-proxy.service
           └─9031 /opt/dnscrypt-proxy/dnscrypt-proxy

nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   279ms gridns-jp
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   293ms publicarray-au2-doh
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   297ms publicarray-au2
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   301ms dnscrypt-07.adsnomore.io
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   327ms publicarray-au
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   336ms publicarray-au-doh
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   344ms quad101
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   367ms geekdns-hk
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] -   373ms dnscrypt-05.adsnomore.io
nov 01 15:37:01 overclock dnscrypt-proxy[9031]: [2019-10-31 15:37:01] [NOTICE] Server with the lowest initial latency: cloudflare (rtt: 15ms)
pi@overclock:~$ /opt/dnscrypt-proxy/./dnscrypt-proxy -version
2.0.31
pi@overclock:~$

Ya tendremos el programa actualizado