Cloudflare Stubby config

stubby.xml

#
# This is a yaml version of the stubby configuration file (it replaces the 
# json based stubby.conf file used in earlier versions of getdns/stubby).
#
# For more information see
# https://dnsprivacy.org/wiki/display/DP/Configuring+Stubby
#
# This format does not fully support all yaml features - the restrictions are:
#   - the outer-most data structure must be a yaml mapping
#   - mapping keys must be yaml scalars
#   - plain scalars will be converted to json unchanged
#   - non-plain scalars (quoted, double-quoted, wrapped) will be interpreted
#     as json strings, i.e. double quoted. 
#   - yaml tags are not supported
#   - IPv6 addresses ending in :: are not yet supported (use ::0)
#
# Note that we plan to introduce a more compact format for defining upstreams
# in future: https://github.com/getdnsapi/stubby/issues/79

# Logging is currently configured at runtime using command line arguments. See
# > stubby -h
# for details.

# Specifies whether to run as a recursive or stub resolver 
# For stubby this MUST be set to GETDNS_RESOLUTION_STUB
resolution_type: GETDNS_RESOLUTION_STUB

# Ordered list composed of one or more transport protocols: 
# GETDNS_TRANSPORT_UDP, GETDNS_TRANSPORT_TCP or GETDNS_TRANSPORT_TLS
# If only one transport value is specified it will be the only transport used. 
# Should it not be available basic resolution will fail.
# Fallback transport options are specified by including multiple values in the
# list.  Strict mode (see below) should use only GETDNS_TRANSPORT_TLS.
dns_transport_list:
  - GETDNS_TRANSPORT_TLS

# Selects Strict or Opportunistic Usage profile as described in
# https://datatracker.ietf.org/doc/draft-ietf-dprive-dtls-and-tls-profiles/
# Strict mode requires that authentication information for the upstreams is
# specified below. Opportunistic may fallback to clear text DNS if UDP or TCP
# is included in the transport list above.
# For Strict use        GETDNS_AUTHENTICATION_REQUIRED
# For Opportunistic use GETDNS_AUTHENTICATION_NONE
tls_authentication: GETDNS_AUTHENTICATION_REQUIRED

# EDNS0 option to pad the size of the DNS query to the given blocksize
# 128 is currently recommended by 
# https://tools.ietf.org/html/draft-ietf-dprive-padding-policy-03
tls_query_padding_blocksize: 128

# EDNS0 option for ECS client privacy as described in Section 7.1.2 of
# https://tools.ietf.org/html/rfc7871
edns_client_subnet_private : 1

# EDNS0 option for keepalive idle timeout in ms as specified in
# https://tools.ietf.org/html/rfc7828
# This keeps idle TLS connections open to avoid the overhead of opening a new 
# connection for every query.
idle_timeout: 10000

# Set the listen addresses for the stubby DAEMON. This specifies localhost IPv4
# and IPv6. It will listen on port 53 by default. Use <IP_address>@<port> to 
# specify a different port
listen_addresses:
  - 127.0.0.1
  -  0::1

# Instructs stubby to distribute queries across all available name servers. 
# Set to 0 to treat the upstreams below as an ordered list and use a single
# upstream until it becomes unavailable, then use the next one.
round_robin_upstreams: 1

# Require DNSSEC validation. For releases earlier than 1.2 a trust anchor must
# be configured configured manually. This can be done with unbound-anchor.
# dnssec_return_status: GETDNS_EXTENSION_TRUE

# Specify the location of the installed trust anchor file (leave commented out
# for zero configuration DNSSEC)
# dnssec_trust_anchors: "/etc/unbound/getdns-root.key"

# Control the maximum number of connection failures that will be permitted
# before Stubby backs-off from using an individual upstream (default 2)
# tls_connection_retries: 5

# Control the maximum time in seconds Stubby will back-off from using an
# individual upstream after failures under normal circumstances (default 3600)
# tls_backoff_time: 300

# Limit the total number of outstanding queries permitted
# limit_outstanding_queries: 100

# Specify the timeout on getting a response to an individual request
# (default 5s)
# timeout: 1

# Specify the list of upstream recursive name servers to send queries to
# In Strict mode upstreams need either a tls_auth_name or a tls_pubkey_pinset
# so the upstream can be authenticated.
# The list below includes all the available test servers but only has the subset
# operated the stubby/getdns developers enabled. You can enable any of the
# others you want to use by uncommenting the relevant section. See:
# https://dnsprivacy.org/wiki/display/DP/DNS+Privacy+Test+Servers
# If you don't have IPv6 then comment then out those upstreams.
# In Opportunistic mode they only require an IP address in address_data.
# The information for an upstream can include the following:
# - address_data: IPv4 or IPv6 address of the upstream
#   port: Port for UDP/TCP (default is 53)
#   tls_auth_name: Authentication domain name checked against the server
#                  certificate
#   tls_pubkey_pinset: An SPKI pinset verified against the keys in the server
#                      certificate
#     - digest: Only "sha256" is currently supported
#       value: Base64 encoded value of the sha256 fingerprint of the public
#              key
#   tls_port: Port for TLS (default is 853)
upstream_recursive_servers:
  - address_data: 1.1.1.1
    tls_auth_name: "cloudflare-dns.com"
    tls_pubkey_pinset:
      - digest: "sha256"
        value: RKlx+/Jwn2A+dVoU8gQWeRN2+2JxXcFkAczKfgU8OAI=
  - address_data: 1.0.0.1
    tls_auth_name: "cloudflare-dns.com"
    tls_pubkey_pinset:
      - digest: "sha256"
        value: RKlx+/Jwn2A+dVoU8gQWeRN2+2JxXcFkAczKfgU8OAI=
  - address_data: 2606:4700:4700::1111
    tls_auth_name: "cloudflare-dns.com"
    tls_pubkey_pinset:
      - digest: "sha256"
        value: RKlx+/Jwn2A+dVoU8gQWeRN2+2JxXcFkAczKfgU8OAI=
  - address_data: 2606:4700:4700::1001
    tls_auth_name: "cloudflare-dns.com"
    tls_pubkey_pinset:
      - digest: "sha256"
        value: RKlx+/Jwn2A+dVoU8gQWeRN2+2JxXcFkAczKfgU8OAI=

..and cloudflare have updated their cert - have updated the gist.

Public keys seem to be outdated again. Where and how are you getting them from?

after checking that the address still belongs to cloudflare....
echo | openssl s_client -connect '1.1.1.1:853' 2>/dev/null | openssl x509 -pubkey -noout | openssl pkey -pubin -outform der | openssl dgst -sha256 -binary | openssl enc -base64

Public keys seem to be outdated again. Where and how are you getting them from?

have updated the Gist again. some will say this is a problem with cert pinning but I'd rather know i'm really talking to the box i think i'm talking to . have updated the Gist

Thanks, this is really helpful

after checking that the address still belongs to cloudflare....
echo | openssl s_client -connect '1.1.1.1:853' 2>/dev/null | openssl x509 -pubkey -noout | openssl pkey -pubin -outform der | openssl dgst -sha256 -binary | openssl enc -base64

Public keys seem to be outdated again. Where and how are you getting them from?

have updated the Gist again. some will say this is a problem with cert pinning but I'd rather know i'm really talking to the box i think i'm talking to . have updated the Gist

I agree. Knowing how to get the public key is helpful. Please keep the gist up to date so others can confirm their public keys.

updated with new keys