# Spfcheck
[](https://github.com/hertogp/spfcheck/actions/workflows/elixir.yml)
[](https://hex.pm/packages/spfcheck)
[](https://hexdocs.pm/spfcheck/)
[](https://github.com/hertogp/spfcheck/commits/main)
[](https://github.com/hertogp/spfcheck/blob/main/LICENSE.md)
[](https://hex.pm/packages/spfcheck)
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`spfcheck` is a command line tool to examine and debug SPF records.
## Usage
```txt
Usage: spfcheck [options] [sender ...]
where sender = [localpart@]domain and localpart defaults to 'postmaster'
Options:
-H, --help print this message and exit
-d, --dns=filepath file with DNS RR records to prepopulate the DNS cache
-h, --helo=string sending MTA helo/ehlo identity (defaults to nil)
-i, --ip=string sending MTA IPv4/IPv6 address (defaults to 127.0.0.1)
-r, --report=string either "all" or one of more letters of "vsewpdat" (see below)
-v, --verbosity set logging noise level (0..5), default is 4 (informational)
-w, --width=NUM limits line length to increase readability (defaults to 60)
--no-color turn off colors for log messages
--no-markdown turn off markdown formatting for reports
```
The default is to simply print the verdict and some stats to stdout and print
notification messages to stderr. `spfcheck` passes the
[`rfc7208 test suite`](http://www.open-spf.org/Test_Suite)
and should be reasonably
[`rfc7208`](https://www.rfc-editor.org/rfc/rfc7208.html) compliant.
```txt
% spfcheck example.com --no-color
example.com %spf[0]-spf-note: > spfcheck(example.com, 127.0.0.1, example.com)
example.com %spf[0]-dns-info: > DNS QUERY (1) txt example.com - ["8j5nfqld20zpcyr8xjw0ydcfq9rk8hgm", "v=spf1 -all"]
example.com %spf[0]-eval-note: > spf[0] -all - matches
example.com %spf[0]-dns-info: > DNS QUERY (2) soa example.com - [{"ns.icann.org", "noc.dns.icann.org", 2021111701, 7200, 3600, 1209600, 3600}]
domain : example.com
ip : 127.0.0.1
sender : example.com
verdict : fail
reason : spf[0] -all
owner : example.com
contact : noc@dns.icann.org
num_spf : 1
num_dnsm : 0
num_dnsq : 1
num_dnsv : 0
num_checks : 1
num_warn : 0
num_error : 0
duration : 0
explanation:
```
## Batchmode
If no `sender` is given on the command line, `spfcheck` will read stdin for the
domains (and options) to check. In this case, the verdict(s) are output on
stdout in csv-format as each domain is (sequentially) evaluated.
```txt
% cat senders.txt
example.com
me@example.net -i 1.2.3.4
% cat domains.txt | spfcheck -v 0
domain,ip,sender,verdict,reason,owner,contact,num_spf,num_dnsm,num_dnsq,num_dnsv,num_checks,num_warn,num_error,duration,explanation
"example.com","127.0.0.1","example.com",:fail,"spf[0] -all","example.com","noc@dns.icann.org",1,0,1,0,1,0,0,1,""
"example.net","1.2.3.4","me@example.net",:fail,"spf[0] -all","example.net","noc@dns.icann.org",1,0,1,0,1,0,0,0,""
```
## DNS flag
The `-d` flag can be used to either point to local file with RR-records or
specify DNS data on the command line. If the file exists, it is read and used
to prepopulate the cache. Otherwise, the text will be read as DNS data. This
makes it possible to try out records before publishing them in DNS. That file
should contain 1 RR record per line using the simple `domain type rdata`
format. All `domain`'s are taken to be relative to root ('.').
```txt
% spfcheck example.com -v 0 -d "example.com TXT v=spf1 +all"
domain : example.com
ip : 127.0.0.1
sender : example.com
verdict : pass
reason : spf[0] +all
num_spf : 1
num_dnsm : 0
num_dnsq : 1
num_dnsv : 0
num_checks : 1
num_warn : 0
num_error : 0
duration : 1
explanation:
# Or using a file
% cat tmp/zonedata.txt
# comments are ignored as are empty lines
example.com TXT v=spf1 -all exp=why.%{d}
example.com TXT just another txt record
why.example.com TXT %{d}: %{i} is not one of our MTAs
% spfcheck example.com -v 0 -d tmp/zonedata.txt
domain : example.com
ip : 127.0.0.1
sender : example.com
verdict : fail
reason : spf[0] -all
num_spf : 1
num_dnsm : 0
num_dnsq : 2
num_dnsv : 0
num_checks : 1
num_warn : 0
num_error : 0
duration : 1
explanation: example.com: 127.0.0.1 is not one of our MTAs
```
`spfcheck` counts the number of dns mechanisms seen (dnsm), the number of
queries performed (dnsq) and the number of void dns queries seen (dnsv).
If the evaluation took more than `10` dns mechanisms, the verdict is modified
accordingly.
## Helo flag
The `-h` allows for setting the EHLO domain name and defaults to given
`sender`. Note that `spfcheck` only checks SPF for `sender`, so this is only
useful when checking the expansion of the `%{h}`-macro in a policy.
## Ip flag
The `-i` flag is used to set sender's IP to either an IPv4 or an IPv6 address,
it defaults to `127.0.0.1` as an unlikely address to be authorized by anyone.
The goal is to go down the rabbit hole as far as possible and check the entire
nested SPF policy for given `sender`.
## No color
The `--no-color` flag disables the use of colors in log messages, which is
better when redirecting logging to a file.
For example:
```txt
%cat tmp/domains.txt
example.com
me@example.net -i 1.2.3.4
% cat tmp/domains.txt | spfcheck -v 5 --no-color 2>tmp/log.txt > tmp/checked.csv
% cat tmp/log.txt
example.com %spf[0]-ctx-debug: > created context for example.com
example.com %spf[0]-spf-note: > spfcheck(example.com, 127.0.0.1, example.com)
example.com %spf[0]-dns-debug: > added {example.com, txt} -> "8j5nfqld20zpcyr8xjw0ydcfq9rk8hgm"
example.com %spf[0]-dns-debug: > added {example.com, txt} -> "v=spf1 -all"
example.com %spf[0]-dns-info: > DNS QUERY (1) txt example.com - ["v=spf1 -all", "8j5nfqld20zpcyr8xjw0ydcfq9rk8hgm"]
example.com %spf[0]-eval-info: > spf[0] -all - matches
example.com %spf[0]-dns-debug: > added {example.com, soa} -> {"ns.icann.org", "noc.dns.icann.org", 2021111701, 7200, 3600, 1209600, 3600}
example.com %spf[0]-dns-info: > DNS QUERY (2) soa example.com - [{"ns.icann.org", "noc.dns.icann.org", 2021111701, 7200, 3600, 1209600, 3600}]
example.net %spf[0]-ctx-debug: > created context for example.net
example.net %spf[0]-spf-note: > spfcheck(example.net, 1.2.3.4, me@example.net)
example.net %spf[0]-dns-debug: > added {example.net, txt} -> "v=spf1 -all"
example.net %spf[0]-dns-debug: > added {example.net, txt} -> "5fpl1ghm7scnth0907z0pft8c79lvc8t"
example.net %spf[0]-dns-info: > DNS QUERY (1) txt example.net - ["5fpl1ghm7scnth0907z0pft8c79lvc8t", "v=spf1 -all"]
example.net %spf[0]-eval-info: > spf[0] -all - matches
example.net %spf[0]-dns-debug: > added {example.net, soa} -> {"ns.icann.org", "noc.dns.icann.org", 2021111701, 7200, 3600, 1209600, 3600}
example.net %spf[0]-dns-info: > DNS QUERY (2) soa example.net - [{"ns.icann.org", "noc.dns.icann.org", 2021111701, 7200, 3600, 1209600, 3600}]
```
## Report flag
The `-r` flag can be used to print out some information, topics include:
- `v` the verdict and some statistics
- `s` the spf records seen and their authority information
- `e` the errors seen
- `w` the warnings seen
- `p` the prefixes collected
- `d` DNS information collected
- `a` the AST for the (first) SPF record
- `t` the tokens for the (last) SPF record seen
In case no `-r` flag is used, spfcheck will simply print out the verdict.
```txt
% spfcheck example.com -v 0 -r s --no-markdown
[0] example.com -- (example.com, noc@dns.icann.org)
v=spf1 -all
```
Here, the SPF section lists all SPF records seen along with the authoritative
domain and its DNS admin email.
## Verbosity flag
The `-v` flag controls the verbosity level of logging on stderr:
- 0 - no messages at all
- 1 - errors
- 2 - warnings
- 3 - notifications
- 4 - informational
- 5 - debug
```txt
% spfcheck example.com -v 5 --no-color
example.com %spf[0]-ctx-debug: > created context for example.com
example.com %spf[0]-spf-note: > spfcheck(example.com, 127.0.0.1, example.com)
example.com %spf[0]-dns-debug: > added {example.com, txt} -> "v=spf1 -all"
example.com %spf[0]-dns-debug: > added {example.com, txt} -> "8j5nfqld20zpcyr8xjw0ydcfq9rk8hgm"
example.com %spf[0]-dns-info: > DNS QUERY (1) txt example.com - ["8j5nfqld20zpcyr8xjw0ydcfq9rk8hgm", "v=spf1 -all"]
example.com %spf[0]-spf-note: > SPF (0): ["v=spf1 -all"]
example.com %spf[0]-eval-info: > spf[0] -all - matches
domain : example.com
ip : 127.0.0.1
sender : example.com
verdict : fail
reason : spf[0] -all
num_spf : 1
num_dnsm : 0
num_dnsq : 1
num_dnsv : 0
num_checks : 1
num_warn : 0
num_error : 0
duration : 1
explanation:
```
## Width flag
Finally, the `-w` flag can be used to control the width used when printing
information of certain topics. Primarily meant so a markdown formatted report
can be easily converted to pdf. Default value is 60, but you can make it as
wide as necessary.
<!-- @MODULEDOC -->
## Installation
You can install `spfcheck` as an escript:
```bash
mix escript.install hex spfcheck
```
After installation, `~/.mix/escripts/spfcheck` invokes the escript.
Or use it in a project by adding `spfcheck` to the list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:spfcheck, "~> 0.3.0"}
]
end
```
