2025-12-25 upload

venv/Lib/site-packages/mitmproxy/net/check.py

@@ -0,0 +1,43 @@
+import ipaddress
+import re
+from typing import AnyStr
+
+# Allow underscore in host name
+# Note: This could be a DNS label, a hostname, a FQDN, or an IP
+
+_label_valid = re.compile(rb"[A-Z\d\-_]{1,63}$", re.IGNORECASE)
+
+
+def is_valid_host(host: AnyStr) -> bool:
+    """
+    Checks if the passed bytes are a valid DNS hostname or an IPv4/IPv6 address.
+    """
+    if isinstance(host, str):
+        try:
+            host_bytes = host.encode("idna")
+        except UnicodeError:
+            return False
+    else:
+        host_bytes = host
+    try:
+        host_bytes.decode("idna")
+    except ValueError:
+        return False
+    # RFC1035: 255 bytes or less.
+    if len(host_bytes) > 255:
+        return False
+    if host_bytes and host_bytes.endswith(b"."):
+        host_bytes = host_bytes[:-1]
+    # DNS hostname
+    if all(_label_valid.match(x) for x in host_bytes.split(b".")):
+        return True
+    # IPv4/IPv6 address
+    try:
+        ipaddress.ip_address(host_bytes.decode("idna"))
+        return True
+    except ValueError:
+        return False
+
+
+def is_valid_port(port: int) -> bool:
+    return 0 <= port <= 65535