From 2667ed44f5790d5b1e3976895bdeff7dfe2163cd Mon Sep 17 00:00:00 2001
From: Maximilian Hils <git@maximilianhils.com>
Date: Sat, 30 Sep 2023 00:51:05 +0200
Subject: [PATCH] add DNS-over-HTTPS contentview

---
 CHANGELOG.md                            |  2 ++
 mitmproxy/contentviews/__init__.py      |  2 ++
 mitmproxy/contentviews/dns.py           | 20 ++++++++++++++++++++
 test/mitmproxy/contentviews/test_dns.py | 21 +++++++++++++++++++++
 4 files changed, 45 insertions(+)
 create mode 100644 mitmproxy/contentviews/dns.py
 create mode 100644 test/mitmproxy/contentviews/test_dns.py

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8b7c37fb8..fdbec23f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 * Add a raw hex stream contentview.
   ([#6389](https://github.com/mitmproxy/mitmproxy/pull/6389), @mhils)
+* Add a contentview for DNS-over-HTTPS.
+  ([#6389](https://github.com/mitmproxy/mitmproxy/pull/6389), @mhils)
 
 
 ## 27 September 2023: mitmproxy 10.1.1
diff --git a/mitmproxy/contentviews/__init__.py b/mitmproxy/contentviews/__init__.py
index 4185d0486..3f25d14c6 100644
--- a/mitmproxy/contentviews/__init__.py
+++ b/mitmproxy/contentviews/__init__.py
@@ -15,6 +15,7 @@ import traceback
 
 from . import auto
 from . import css
+from . import dns
 from . import graphql
 from . import grpc
 from . import hex
@@ -238,6 +239,7 @@ add(msgpack.ViewMsgPack())
 add(grpc.ViewGrpcProtobuf())
 add(mqtt.ViewMQTT())
 add(http3.ViewHttp3())
+add(dns.ViewDns())
 
 __all__ = [
     "View",
diff --git a/mitmproxy/contentviews/dns.py b/mitmproxy/contentviews/dns.py
new file mode 100644
index 000000000..58e6b52f4
--- /dev/null
+++ b/mitmproxy/contentviews/dns.py
@@ -0,0 +1,20 @@
+from mitmproxy.contentviews import base
+from mitmproxy.contentviews.json import format_json
+from mitmproxy.dns import Message
+
+
+class ViewDns(base.View):
+    name = "DNS-over-HTTPS"
+
+    def __call__(self, data, **metadata):
+        try:
+            message = Message.unpack(data)
+        except Exception:
+            pass
+        else:
+            return "DoH", format_json(message.to_json())
+
+    def render_priority(
+        self, data: bytes, *, content_type: str | None = None, **metadata
+    ) -> float:
+        return float(content_type == "application/dns-message")
diff --git a/test/mitmproxy/contentviews/test_dns.py b/test/mitmproxy/contentviews/test_dns.py
new file mode 100644
index 000000000..f10296ade
--- /dev/null
+++ b/test/mitmproxy/contentviews/test_dns.py
@@ -0,0 +1,21 @@
+from . import full_eval
+from mitmproxy.contentviews import dns
+
+DNS_HTTPS_RECORD_RESPONSE = bytes.fromhex(
+    "00008180000100010000000107746c732d656368036465760000410001c00c004100010000003c00520001000005004b0049fe0d00"
+    "452b00200020015881d41a3e2ef8f2208185dc479245d20624ddd0918a8056f2e26af47e2628000800010001000100034012707562"
+    "6c69632e746c732d6563682e646576000000002904d0000000000000"
+)
+
+
+def test_simple():
+    v = full_eval(dns.ViewDns())
+    assert v(DNS_HTTPS_RECORD_RESPONSE)
+    assert not v(b"foobar")
+
+
+def test_render_priority():
+    v = dns.ViewDns()
+    assert v.render_priority(b"", content_type="application/dns-message")
+    assert not v.render_priority(b"", content_type="text/plain")
+    assert not v.render_priority(b"")