NAME

SYNOPSIS

DESCRIPTION

dnsdbq displays responses in various formats. Its default query type is a "lookup" query. As an option, it can issue a "summarize" query type. Different Passive DNS systems or versions of those systems may implement different query features.

FARSIGHT SECURITY'S DNSDB

You'll need to get an API key from Farsight to use dnsdbq with DNSDB.

Farsight's passive DNS infrastructure performs a complex process of "bailiwick reconstruction" where an RRset's position within the DNS hierarchy is approximated. This serves two purposes:

1. Provide context of the location of a given DNS record within the DNS hierarchy.
2. Prevent "untrustworthy" records that are a result of intentional or unintentional cache poisoning attempts from being replicated by downstream consumers.

For example, given the fully qualified domain name www.dachshund.example.com, valid bailiwicks would be dachshund.example.com, example.com, or com.

OPTIONS

-a

enables ASINFO/CIDR annotation for IP addresses in A (IPv4 address) RRsets. The metadata thus appended depends on which data source is given by -D.

-A timestamp

Specify a forward time fence. Only results seen by the passive DNS on or after this time will be selected. See also -c. See the TIMESTAMP FORMATS section for more information about this.

-B timestamp

Specify a backward time fence. Only results seen by the passive DNS sensor network on or before this time will be selected. See also -c. See the TIMESTAMP FORMATS section for more information about this.

-b bailiwick

specify bailiwick (only valid with -r queries).

-c

by default, -A and -B (separately or together) will select partial overlaps of database tuples and time search criteria. To match only completely bracketed tuples, add the -c ("completeness") flag (this is also known as "strict" mode). Can only be specified once, and for reasons of geometry, affects both -A and -B if both are specified.

-D

specify the data source for ASINFO/CIDR annotations, if enabled by -a. Default is asn.routeviews.org, but you may wish to try aspath.routeviews.org.

-d

enable debug mode. Repeat for more debug output.

-f

specify batch lookup mode allowing one or more queries to be performed. Queries will be read from standard input and are expected to be in one of the following formats:

• RRset (name) query: rrset/name/NAME[/RRTYPE[,...][/BAILIWICK]]
• RRset (raw) query: rrset/raw/HEX[/RRTYPE[,...][/BAILIWICK]]
• Rdata (name) query: rdata/name/NAME[/RRTYPE][,...]
• Rdata (IP address) query: rdata/ip/ADDR[,PFXLEN]
• Rdata (raw) query: rdata/raw/HEX[/RRTYPE][,...]
• Change query options: $OPTIONS {options}

Where options :==

[-A timestamp] [-B timestamp] [-c] [-g] [-G]
[-l query_limit] [-L output_limit] [-O offset]
    

$OPTIONS alone on a line allows command line options to be changed mid-batch. If no options are given, the query parameters will be reset to those given on the command line, if any, or else to defaults.

A line starting with a # will be ignored as a comment.

Any internal slash (/) or comma (,) characters within the search names of a batch entry must be URL-encoded (for example, %2F or %2C). So, to search for the domain "212.0/24.150.104.24.in-addr.arpa" the search string would be specified as "212.0%2F150.104.24.in-addr.arpa".

For raw queries, the hex value is an even number of hexadecimal digits specifying a raw octet string. The "raw" wire-format encodings are standardized. The embedding of these in dnstable is documented in the dnstable-encoding(5) manual page. This topic is explained in detail at <https://www.farsightsecurity.com/blog/txt-record/dnsdb-rawhex-20161125>.

In batch lookup mode, each answer will be followed by a '--' marker, so that programmatic users will know when it is safe to send the next lookup, or if lookups are pipelined, to know when one answer has ended and another begun. This option cannot be mixed with -n, -r, -R, or -i. See the EXAMPLES section for more information on how to use -f.

If two -f options are given, then each answer will also be preceded by a '++' marker giving the query string (as read from the batch input) in order to identify each answer when a very large batch input is given, and the '--' marker will include an error/noerror indicator and a short message describing the outcome. With two -f options and also -m, answers can appear in a different order than the batched questions, and the

-g

return graveled results if available. The default is to return aggregated results ("rocks"). Gravel is a feature for providing Volume Across Time. Note that not all Passive DNS system APIs support this feature, and not all time ranges contain granular results ("gravel").

-G

undo the effect of -g, this returning rocks rather than gravel. (Used in $OPTIONS in batch files.)

-h

emit usage and quit.

-I

request information from the API server concerning the API key itself, which may include rate limit, query quota, query allowance, or privilege levels; the output format and content is dependent on the server_sys argument (see -u ) and upon the -p argument. -I -p json prints the raw info. -I -p text prints the information in a more understandable textual form, including converting any epoch integer times into UTC formatted times.

-i ip

specify rdata ip ("right-hand side") query. The value is one of an IPv4 address, an IPv6 address, an IPv4 network with prefix length, an IPv4 address range, or an IPv6 network with prefix length. If a network lookup is being performed, the delimiter between network address and prefix length is a single comma (",") character rather than the usual slash ("/") character to avoid clashing with the HTTP URI path name separator. See EXAMPLES section for more information about separator substitution rules.

-J input_file

opens input_file and reads newline-separated JSON objects therefrom, in preference to -f (batch mode) or query mode. This can be used to reprocess the output from a prior invocation which used -j (or -p json). Sorting, limits, and time fences will work. Specification of a domain name, RRtype, Rdata, or offset is not supported at this time. If input_file is "-" then standard input (stdin) will be read.

-j

synonym for -p json.

-k sort_keys

when sorting with -s or -S, selects one or more comma separated sort keys, among "first", "last", "duration", "count", "name", "type", and/or "data". The default order is be "first,last,duration,count,name,type,data" (if sorting is requested.) Names are sorted right to left (by TLD then 2LD etc). Data is sorted either by name if present, or else by numeric value (e.g., for A and AAAA RRsets.) Several -k options can be given after different -s and -S options, to sort in ascending order for some keys, descending for others.

-l query_limit

query for that limit's number of responses. If specified as 0 then the DNSDB API server will return the maximum limit of results allowed. If -l, is not specified, then the query will not specify a limit, and the DNSDB API server may use its default limit.

-L output_limit

clamps the number of objects per response (under -[R|r|N|n|i|f]) or for all responses (under -[fm|ff|ffm]) output to output_limit. If unset, and if batch and merge modes have not been selected with the -f and -m options, then the -L output limit defaults to the -l limit's value. Otherwise the default is no output limit.

-M max_count

for the summarize verb, stops summarizing when the count reaches that max_count, which must be a positive integer. The resulting total count may exceed max_count as it will include the entire count from the last RRset examined. The default is to not constrain the maximum count. The number of RRsets summarized is also limited by the query_limit.

-m

used only with -f, this causes multiple (up to ten) API queries to execute in parallel. In this mode there will be no "--" marker, and the combined output of all queries is what will be subject to sorting, if any. If two -f flags are specified with -m, the output will not be merged, can appear in any order, will be sorted separately for each response, and will have normal '--' and '++' markers. (See -f option above.)

-N hex[/rrtype[,...]]

specify raw rdata data ("right-hand side") query. Hex is as described above for -f.

-n name

specify rdata name ("right-hand side") query. The value is a DNS domain name in presentation format, or a left-hand ("*.example.com") or right-hand ("www.example.*") wildcard domain name. Note that left-hand wildcard queries are somewhat more expensive than right-hand wildcard queries.

-O offset

to offset by #offset the results returned by the query. This gives you incremental results transfers. Cannot be negative. The default is 0 which means no offset.

-p output_type

select output type. Specify:

text

for presentation output meant to be human-readable. This is the default. dns is a synonym, for compatibility with older programmatic callers.

json

for newline delimited JSON output. See also <https://jsonlines.org/>.

csv

for comma separated value output. This format is information losing, since it cannot express multiple resource records that are in a single RRset. Instead, each resource record is expressed in a separate line of output. See the DNSDBQ_TIME_FORMAT environment variable for controlling how timestamps are formatted for this option.

minimal

outputs only the owner name or rdata, one per line and deduplicated; for use by shell scripts.

-q

makes the program reticent about warnings.

-R hex[/rrtype[,...][/bailiwick]]

specify raw rrset owner data ("left-hand side") query. Hex is as described above for -f.

-r name[/type[,...][/bailiwick]]

specify RRset ("left-hand side") name query. See discussion in -n above as to the format of and limitations on query names.

-s

sort output in ascending key order. Limits (if any) specified by -l and -L will be applied before and after sorting, respectively. In batch mode, the -f, -ff, and -ffm option sets will cause each batch entry's result to be sorted independently, whereas with -fm, all outputs will be combined before sorting. This means with -fm there will be no output until after the last batch entry has been processed, due to store and forward by the sort process.

-S

sort output in descending key order. See discussion for -s above.

-T transform[,...]

specify one or more transforms to be applied to the output:

datefix

always show dates in the format selected by the DNSDBQ_TIME_FORMAT environment variable, not in database format.

reverse

show the DNS owner name (rrname) in TLD-first order (so, COM.EXAMPLE rather than EXAMPLE.COM).

chomp

strip away the trailing dot (.) from the DNS owner name (rrname).

-t rrtype[,...]

specify the resource record type(s) desired. Default is ANY. If present, this option should precede any -R, -r, -N, or -n options. This option is not allowed if the -i option is present. Valid values include those defined in DNS RFCs, including ANY. A special-case supported in DNSDB is ANY-DNSSEC, which matches on DS, RRSIG, NSEC, DNSKEY, NSEC3, NSEC3PARAM, and DLV resource record types.

If multiple rrtype values are specified, each will be sent separately to the database server, consuming quota if there is a quota. Such queries will be sent simultaneously in parallel, which may have a load impact on the server.

-u server_sys

specifies the Passive DNS system and thus its syntax for RESTful URLs. Can be "dnsdb" or "circl". The default is "dnsdb". See also environment variable DNSDBQ_SYSTEM.

-V verb

The verb to perform, i.e. the type of query, either "lookup" or "summarize". The default is the "lookup" verb. As an option, you can specify the "summarize" verb, which gives you an estimate of result size. At a glance, it provides information on when a given domain name, IP address or other DNS asset was first-seen and last-seen by the global sensor network, as well as the total sensor network observation count. This verb respects the database limit (see -l) in that the resulting summary will only be of rows that would have been returned by the "lookup" verb. See also -M.

-0 function=thing

This is a developer tool meant to feed automated testing systems.

-U

turns off TLS certificate verification (unsafe).

-v

report the version of dnsdbq and exit.

-4

use to force connecting to the DNSDB server via IPv4.

-6

use to force connecting to the DNSDB server via IPv6.

-8

Normally dnsdbq requires that -n or -r arguments are 7-bit ASCII clean. Non-ASCII values should be queried using PUNYCODE IDN encoding. This -8 option allows using arbitrary 8 bit values.

TIMESTAMP FORMATS

• positive unsigned integer : in Unix epoch format.
• negative unsigned integer : negative offset in seconds from now.
• YYYY-MM-DD [HH:MM:SS] : in absolute form, in UTC time, as DNSDB does its fencing using UTC time.
• %uw%ud%uh%um%us : the relative form with explicit labels (w=weeks, d=days, h=hours, m=minutes, s=seconds). Calculates offset from UTC time, as DNSDB does its fencing using UTC time.

When using batch mode with the second or forth cases, using relative times to now, the value for "now" is set when dnsdbq starts.

A few examples of how to use timefencing options.

# tuples ending after Aug 22, 2015 (midnight)
$ dnsdbq ... -A 2015-08-22
# tuples starting before Jan 22, 2013 (midnight)
$ dnsdbq ... -B 2013-01-22
# tuples starting or ending from 2015 (midnight to midnight)
$ dnsdbq ... -B 2016-01-01 -A 2015-01-01
# tuples ending after 2015-08-22 14:36:10
$ dnsdbq ... -A "2015-08-22 14:36:10"
# tuples ending within the last 60 minutes
$ dnsdbq ... -A "-3600"
# tuples ending after "just now"
$ date +%s
1485284066
$ dnsdbq ... -A 1485284066
# batch mode with only tuples ending within last 60 minutes,
# even if feeding inputs to dnsdbq in batch mode takes hours.
$ dnsdbq -f ... -A "-3600"

EXAMPLES

# specify a single IPv4 address
$ dnsdbq ... -i 128.223.32.35
# specify an IPv4 CIDR
$ dnsdbq ... -i 128.223.32.0/24
# specify a range of IPv4 addresses
$ dnsdbq ... -i 128.223.32.0-128.223.32.32

Perform an RRset query for a single A record for farsightsecurity.com. The output is serialized as JSON and is piped to the jq program (a command-line JSON processor, see <https://stedolan.github.io/jq/>) for pretty printing.

$ dnsdbq -r farsightsecurity.com/A -l 1 -j -a | jq .
{
  "count": 6350,
  "time_first": 1380123423,
  "time_last": 1427869045,
  "rrname": "farsightsecurity.com.",
  "rrtype": "A",
  "bailiwick": "farsightsecurity.com.",
  "rdata": [
    "66.160.140.81"
  ],
  "dnsdbq-rdata": [
    {
      "asinfo": [ 6939 ],
      "cidr": "66.160.128.0/18",
      "rdata": "66.160.140.81"
    }
  ]
}

Note the "dnsdbq-rdata" element added due to the use of the -a option.

Perform a batched operation for a several different rrset and rdata queries. Output is again serialized as JSON and redirected to a file.

$ cat batch.txt
rrset/name/wikipedia.org
rrset/name/dmoz.org
rrset/raw/0366736902696f00/A
rdata/name/pbs.org
rdata/name/opb.org
rdata/ip/198.35.26.96
rdata/ip/23.21.237.0,24
rdata/raw/0b763d73706631202d616c6c
$ dnsdbq -j -f < batch.txt > batch-output.json
$ head -1 batch-output.json | jq .
{
  "count": 2411,
  "zone_time_first": 1275401003,
  "zone_time_last": 1484841664,
  "rrname": "wikipedia.org.",
  "rrtype": "NS",
  "bailiwick": "org.",
  "rdata": [
    "ns0.wikimedia.org.",
    "ns1.wikimedia.org.",
    "ns2.wikimedia.org."
  ]
}

ASINFO/CIDR LOOKUPS

For best results, always use an on-server or on-LAN recursive DNS service, and consider whether to configure that recursive DNS service to be a "stealth secondary" of the zone denoted by the -D option. For the default -D value, more information can be found online at http://archive.routeviews.org/dnszones/.

Use of DNS lookups to retrieve ASINFO/CIDR metadata can be extremely fast and surveillance-free, but some attention must be paid in order to obtain that outcome. For occasional low-volume use, your current recursive DNS placement and configuration is probably good enough.

Note that while Passive DNS information is historical, the ASINFO/CIDR annotations made possible using the -a and -D options are based on current information. Internet routing system information may have changed since the DNS data was recorded. More information about this can be found online at https://github.com/dnsdb/dnsdbq/blob/master/README.

FILES

The variables which can be set in the configuration file are as follows:

DNSDBQ_SYSTEM

contains the default value for the -u option described above. The last setting found for any given variable will prevail.

DNSDB_API_KEY, APIKEY

contains the user's DNSDB apikey (no default).

DNSDB_SERVER

contains the URL of the DNSDB API server (default is https://api.dnsdb.info), and optionally the URI prefix for the database. The default URI prefix for system "dnsdb2" is "/dnsdb/v2/lookup"; the default for "dnsdb1" is "/lookup".

CIRCL_AUTH, CIRCL_SERVER

enable access to a passive DNS system compatible with the CIRCL.LU system.

ENVIRONMENT

DNSDBQ_CONFIG_FILE

specifies the configuration file to use, overriding the internal search list.

DNSDB_API_KEY

contains the user's apikey. The older APIKEY environment variable has been retired, though it can still be used in the configuration file. Note that environment variables are unprotected, and putting one's API key in an unprotected place could cause inadvertant sharing.

DNSDB_SERVER

contains the URL of the DNSDB API server, and optionally a URI prefix to be used (default is "/lookup"). If not set, the configuration file is consulted.

DNSDBQ_TIME_FORMAT

controls how human readable date times are presented in the output. If "iso" (the default) then ISO8601 (RFC3339) format is used, for example; "2018-09-06T22:48:00Z". If "csv" then an Excel CSV compatible format is used; for example, "2018-09-06 22:48:00".

EXIT STATUS

SEE ALSO