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-rw-r--r--abusectl/contacts.py108
-rw-r--r--tests/test_contacts.py113
2 files changed, 221 insertions, 0 deletions
diff --git a/abusectl/contacts.py b/abusectl/contacts.py
new file mode 100644
index 0000000..c4c263d
--- /dev/null
+++ b/abusectl/contacts.py
@@ -0,0 +1,108 @@
+# Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+"""Indicators to abuse contacts: which ones resolve, and to what.
+
+THE FOURTH NON-NEGOTIABLE PROPERTY lives here. An RDAP query tells a third
+party what the user is looking at, so a query carries a BARE HOST OR IP
+ADDRESS and never a URL.
+
+A URL path can carry recipient identity. parse.suspect_path_segments()
+FLAGS those rather than redacting them, deliberately, because a path
+segment may be the thing being reported, and that decision is safe only
+while the URL stays local. Property 1 governs what is PUBLISHED; a query
+is a disclosure that appears in no report, so property 1 does not cover
+it and this one does.
+
+Concretely: a url indicator contributes its HOST to the worklist and
+nothing else. Path, query and fragment never leave the machine.
+
+This is a trap rather than a theoretical concern. The obvious
+implementation resolves "a contact for each indicator" by reading each
+indicator's value, and for a url indicator that value is an entire URL.
+"""
+
+import ipaddress
+import urllib.parse
+from dataclasses import dataclass, field
+
+from . import rdap
+
+
+@dataclass
+class WorkItem:
+ """One thing to ask a registry about, and every indicator behind it."""
+
+ kind: str # "ip" or "domain"
+ query: str
+ iocs: list[str] = field(default_factory=list)
+
+
+def _host_of(url: str) -> str | None:
+ """Return the bare host of a URL: no userinfo, no port, no path.
+
+ urlsplit().hostname does all three, which is why it is used rather
+ than netloc: netloc still carries userinfo and a port.
+ """
+ try:
+ parts = urllib.parse.urlsplit(url)
+ except ValueError:
+ return None
+ host = parts.hostname
+ if not host:
+ return None
+ return host.strip(".").lower() or None
+
+
+def _is_ip(value: str) -> bool:
+ try:
+ ipaddress.ip_address(value)
+ return True
+ except ValueError:
+ return False
+
+
+def worklist(iocs: list[dict]) -> list[WorkItem]:
+ """Build the deduplicated list of queries for a set of indicators.
+
+ Hosts fold: twenty URLs on one host produce one query, and the item
+ keeps every indicator id that contributed so nothing is lost.
+ """
+ items: dict[tuple[str, str], WorkItem] = {}
+
+ def add(kind, query, ioc_id):
+ key = (kind, query)
+ if key not in items:
+ items[key] = WorkItem(kind=kind, query=query)
+ if ioc_id not in items[key].iocs:
+ items[key].iocs.append(ioc_id)
+
+ for ioc in iocs:
+ ioc_type = ioc.get("type")
+ value = ioc.get("value") or ""
+ ioc_id = ioc.get("id")
+
+ if ioc_type in ("ipv4", "ipv6"):
+ if _is_ip(value):
+ add("ip", value, ioc_id)
+ elif ioc_type == "domain":
+ host = value.strip(".").lower()
+ if host:
+ add("ip" if _is_ip(host) else "domain", host, ioc_id)
+ elif ioc_type == "url":
+ host = _host_of(value)
+ if host:
+ add("ip" if _is_ip(host) else "domain", host, ioc_id)
+
+ return list(items.values())
diff --git a/tests/test_contacts.py b/tests/test_contacts.py
new file mode 100644
index 0000000..a6ddabe
--- /dev/null
+++ b/tests/test_contacts.py
@@ -0,0 +1,113 @@
+# Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+"""Tests for turning indicators into abuse contacts."""
+
+import unittest
+
+from abusectl import contacts
+
+
+class Worklist(unittest.TestCase):
+ def test_ips_and_domains_are_resolvable(self):
+ iocs = [
+ {"id": "ioc-1", "type": "ipv4", "value": "198.51.100.7"},
+ {"id": "ioc-2", "type": "domain", "value": "example.invalid"},
+ ]
+ work = contacts.worklist(iocs)
+ self.assertEqual(
+ {(item.kind, item.query) for item in work},
+ {("ip", "198.51.100.7"), ("domain", "example.invalid")},
+ )
+
+ def test_hashes_and_observations_are_not_resolvable(self):
+ iocs = [
+ {"id": "ioc-1", "type": "sha256", "value": "e3b0c442"},
+ {"id": "ioc-2", "type": "observation",
+ "value": "display-name-carries-address"},
+ ]
+ self.assertEqual(contacts.worklist(iocs), [])
+
+ def test_a_url_contributes_only_its_host(self):
+ """THE FOURTH PROPERTY. A query discloses what the user is looking
+ at, and a URL path can carry recipient identity that
+ suspect_path_segments deliberately flags rather than redacts."""
+ iocs = [{
+ "id": "ioc-1", "type": "url",
+ "value": "https://login.example.invalid/verify/victim%40example.org?e=REDACTED",
+ }]
+ work = contacts.worklist(iocs)
+ self.assertEqual(len(work), 1)
+ self.assertEqual(work[0].kind, "domain")
+ self.assertEqual(work[0].query, "login.example.invalid")
+
+ def test_url_userinfo_never_reaches_the_query(self):
+ iocs = [{
+ "id": "ioc-1", "type": "url",
+ "value": "https://victim%40example.org:secret@login.example.invalid/x",
+ }]
+ work = contacts.worklist(iocs)
+ self.assertEqual(work[0].query, "login.example.invalid")
+
+ def test_a_url_port_is_stripped(self):
+ iocs = [{"id": "ioc-1", "type": "url",
+ "value": "https://login.example.invalid:8443/x"}]
+ self.assertEqual(contacts.worklist(iocs)[0].query, "login.example.invalid")
+
+ def test_a_url_host_that_is_an_ip_resolves_as_an_ip(self):
+ iocs = [{"id": "ioc-1", "type": "url",
+ "value": "http://198.51.100.7/login"}]
+ work = contacts.worklist(iocs)
+ self.assertEqual(work[0].kind, "ip")
+ self.assertEqual(work[0].query, "198.51.100.7")
+
+ def test_a_bracketed_ipv6_url_host_resolves_as_an_ip(self):
+ iocs = [{"id": "ioc-1", "type": "url",
+ "value": "http://[2001:db8::1]/login"}]
+ work = contacts.worklist(iocs)
+ self.assertEqual(work[0].kind, "ip")
+ self.assertEqual(work[0].query, "2001:db8::1")
+
+ def test_hosts_fold_and_keep_every_contributing_ioc(self):
+ """Twenty URLs on one host must produce one query."""
+ iocs = [
+ {"id": "ioc-1", "type": "url", "value": "https://a.example.invalid/one"},
+ {"id": "ioc-2", "type": "url", "value": "https://a.example.invalid/two"},
+ {"id": "ioc-3", "type": "domain", "value": "a.example.invalid"},
+ ]
+ work = contacts.worklist(iocs)
+ self.assertEqual(len(work), 1)
+ self.assertEqual(work[0].iocs, ["ioc-1", "ioc-2", "ioc-3"])
+
+ def test_a_trailing_dot_folds_with_the_bare_host(self):
+ iocs = [
+ {"id": "ioc-1", "type": "domain", "value": "example.invalid."},
+ {"id": "ioc-2", "type": "domain", "value": "example.invalid"},
+ ]
+ self.assertEqual(len(contacts.worklist(iocs)), 1)
+
+ def test_an_untrusted_hop_is_still_resolved(self):
+ """A forged chain's IP may still be the real sender's; the
+ confidence marker stays in the manifest for review."""
+ iocs = [{"id": "ioc-1", "type": "ipv4", "value": "203.0.113.99",
+ "confidence": "untrusted-hop"}]
+ self.assertEqual(len(contacts.worklist(iocs)), 1)
+
+ def test_a_malformed_url_contributes_nothing(self):
+ iocs = [{"id": "ioc-1", "type": "url", "value": "not a url"}]
+ self.assertEqual(contacts.worklist(iocs), [])
+
+
+if __name__ == "__main__":
+ unittest.main()