Mail::SpamAssassin::Plugin::HashBL - query hashed (and unhashed) DNS blocklists

NAME  SYNOPSIS  DESCRIPTION 

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NAME

HashBL − query hashed (and unhashed) DNS blocklists

SYNOPSIS

loadplugin Mail::SpamAssassin::Plugin::HashBL
# NON−WORKING usage examples below, replace xxx.example.invalid with real list
# See documentation below for detailed usage
header HASHBL_EMAIL eval:check_hashbl_emails('ebl.example.invalid')
describe HASHBL_EMAIL Message contains email address found on EBL
tflags HASHBL_EMAIL net
# rewrite googlemail.com −> gmail.com, applied before acl/welcomelist
hashbl_email_domain_alias gmail.com googlemail.com
# only query gmail.com addresses
hashbl_acl_freemail gmail.com
header HASHBL_OSENDR eval:check_hashbl_emails('rbl.example.invalid/A', 'md5/max=10/shuffle', 'X−Original−Sender', 'ˆ127\.', 'freemail')
describe HASHBL_OSENDR Message contains email address found on HASHBL
tflags HASHBL_OSENDR net
body HASHBL_BTC eval:check_hashbl_bodyre('btcbl.example.invalid', 'sha1/max=10/shuffle', '\b([13][a−km−zA−HJ−NP−Z1−9]{25,34})\b')
describe HASHBL_BTC Message contains BTC address found on BTCBL
tflags HASHBL_BTC net
header HASHBL_URI eval:check_hashbl_uris('rbl.example.invalid', 'sha1', 'ˆ127\.0\.0\.32$')
describe HASHBL_URI Message contains uri found on rbl
tflags HASHBL_URI net
body HASHBL_ATTACHMENT eval:check_hashbl_attachments('attbl.example.invalid', 'sha256')
describe HASHBL_ATTACHMENT Message contains attachment found on attbl
tflags HASHBL_ATTACHMENT net
# Capture tag using SA 4.0 regex named capture feature
header __X_SOME_ID X−Some−ID =˜ /ˆ(?<XSOMEID>\d{10,20})$/
# Query the tag value as is from a DNSBL
header HASHBL_TAG eval:check_hashbl_tag('idbl.example.invalid/A', 'raw', 'XSOMEID', 'ˆ127\.')

DESCRIPTION

This plugin supports multiple types of hashed or unhashed DNS blocklist queries.
Common OPTS that apply to all functions:

raw no hashing, query as is (can break if value is not valid DNS label)
md5 hash query with MD5
sha1 hash query with SHA1
sha256 hash query with Base32 encoded SHA256
case keep case before hashing, default is to lowercase
max=x maximum number of queries (defaults to 10 if not specified)
shuffle if max exceeded, random shuffle queries before truncating to limit
alldomains do not ignore domains listed in uridnsbl_skip_domains

Multiple options can be separated with slash.

When rule OPTS is empty ('') or missing, default is used as documented by each query type. If any options are defined, then all needed options must be explicitly defined.

header RULE check_hashbl_emails('bl.example.invalid/A', 'OPTS',
'HEADERS', 'ˆ127\.')

Check email addresses from DNS list. Note that "body" can be specified along with headers to search message body for emails. Rule type must always be "header".

Optional DNS query type can be appended to list with /A (default) or /TXT.

Default OPTS: sha1/notag/noquote/max=10/shuffle

Additional supported OPTS:

nodot strip username dots from email
notag strip username tags from email
nouri ignore emails inside uris
noquote ignore emails inside < > or possible quotings
user query userpart of email only
host query hostpart of email only
domain query domain of email only (hostpart+trim_domain)

Default HEADERS: ALLFROM/Reply−To/body

HEADERS refers to slash separated list of Headers to process:

ALL all headers
ALLFROM all From headers as returned by $pms−>all_from_addrs()
EnvelopeFrom message envelope from (Return−Path etc)
<HeaderName> any header as used with header rules or $pms−>get()
body all emails found in message body

If HEADERS is empty ('') or missing, default is used.

Optional subtest regexp to match DNS answer (default: 'ˆ127\.').

For existing public email blocklist, see: http://msbl.org/ebl.html

# Working example, see https://msbl.org/ebl.html before usage
header HASHBL_EMAIL eval:check_hashbl_emails('ebl.msbl.org')
describe HASHBL_EMAIL Message contains email address found on EBL
tflags HASHBL_EMAIL net

Default regex for matching and capturing emails can be overridden with "hashbl_email_regex". Likewise, the default welcomelist can be changed with "hashbl_email_welcomelist". Only change if you know what you are doing, the default welcomelist includes abuse@, postmaster@, hostmaster@, domainmaster@ and few more; see plugin source code for more info about the defaults. "hashbl_email_regex" example: hashbl_email_regex \S+@\S+.com

header RULE check_hashbl_uris('bl.example.invalid/A', 'OPTS', 'ˆ127\.')

Check all URIs parsed from message from DNS list.

Optional DNS query type can be appended to list with /A (default) or /TXT.

Default OPTS: sha1/max=10/shuffle

Optional subtest regexp to match DNS answer (default: 'ˆ127\.').

[raw]body RULE check_hashbl_bodyre('bl.example.invalid/A', 'OPTS',
'\b(match)\b', 'ˆ127\.')

Search body for matching regexp and query the string captured. Regexp must have a single capture ( ) for the string ($1). Rule type must be "body" or "rawbody".

Optional DNS query type can be appended to list with /A (default) or /TXT.

Default OPTS: sha1/max=10/shuffle

Additional supported OPTS:

num remove the chars from the match that are not numbers
replace if a regexp contains replace tags, replace the match of the regexp with the first option
of the regexp, ex. +1 8O8.l23.4567 will be changed to +1 808.123.4567
For the subsitution to work, replace tags must contain only single chars.

Optional subtest regexp to match DNS answer (default: 'ˆ127\.').

header RULE check_hashbl_tag('bl.example.invalid/A', 'OPTS', 'TAGNAME',
'ˆ127\.')

Query value of SpamAssassin tag _TAGNAME_ from DNS list.

Optional DNS query type can be appended to list with /A (default) or /TXT.

Default OPTS: sha1/max=10/shuffle

Additional supported OPTS:

ip only query if value is valid IPv4/IPv6 address
ipv4 only query if value is valid IPv4 address
ipv6 only query if value is valid IPv6 address
revip reverse IP before query
fqdn only query if value is valid FQDN (is_fqdn_valid)
tld only query if value has valid TLD (is_domain_valid)
trim trim name from hostname to domain (trim_domain)
If both ip/ipv4/ipv6 and fqdn/tld are enabled, only either of them is
required to match. Both fqdn and tld are needed for complete FQDN+TLD
check.

Optional subtest regexp to match DNS answer (default: 'ˆ127\.').

header RULE check_hashbl_attachments('bl.example.invalid/A', 'OPTS',
'ˆ127\.')

Check all all message attachments (mimeparts) from DNS list.

Optional DNS query type can be appended to list with /A (default) or /TXT.

Default OPTS: sha1/max=10/shuffle

Additional supported OPTS:

minsize=x skip any parts smaller than x bytes
maxsize=x skip any parts larger than x bytes

Optional subtest regexp to match DNS answer (default: 'ˆ127\.').

Specific attachment filenames can be skipped with "hashbl_ignore". For example "hashbl_ignore safe.pdf".

Specific mime types can be skipped with "hashbl_ignore". For example "hashbl_ignore text/plain".

hashbl_ignore value [value...]

Skip any type of query, if either the hash or original value (email for example) matches. Multiple values can be defined, separated by whitespace. Matching is case−insensitive.

Any host or its domain part matching uridnsbl_skip_domains is also ignored by default.

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