mitmproxy/examples/addons/contentview-custom-grpc.py

"""
Add a custom version of the gRPC/protobuf content view, which parses
protobuf messages based on a user defined rule set.

"""
from mitmproxy import contentviews
from mitmproxy.contentviews.grpc import ViewGrpcProtobuf, ViewConfig, ProtoParser

config: ViewConfig = ViewConfig()
config.parser_rules = [
    # Note:
    #
    # The first two ParserRules use the same flow filter, although one should reply to request messages and the other to responses.
    # Even with '~s' and '~q' filter expressions, the whole flow would be matched (for '~s') or not matched at all (for '~q'), if
    # the contentview displays a http.Message belonging to a flow with existing request and response.
    # The rules would have to be applied on per-message-basis, instead of per-flow-basis to distinguish request and response (the
    # contentview deals with a single message, either request or response, the flow filter with a flow contiaing both).
    #
    # Thus different ParserRule classes are used to restrict rules to requests or responses were needed:
    #
    # - ParserRule: applied to requests and responses
    # - ParserRuleRequest: applies to requests only
    # - ParserRuleResponse: applies to responses only
    #
    # The actual 'filter' definition in the rule, would still match the whole flow. This means '~u' expressions could
    # be used, to match the URL from the request of a flow, while the ParserRuleResponse is only applied to the response.
    ProtoParser.ParserRuleRequest(
        name="Geo coordinate lookup request",
        # note on flowfilter: for tflow the port gets appended to the URL's host part
        filter="example\\.com.*/ReverseGeocode",
        field_definitions=[
            ProtoParser.ParserFieldDefinition(tag="1", name="position"),
            ProtoParser.ParserFieldDefinition(
                tag="1.1",
                name="latitude",
                intended_decoding=ProtoParser.DecodedTypes.double,
            ),
            ProtoParser.ParserFieldDefinition(
                tag="1.2",
                name="longitude",
                intended_decoding=ProtoParser.DecodedTypes.double,
            ),
            ProtoParser.ParserFieldDefinition(tag="3", name="country"),
            ProtoParser.ParserFieldDefinition(tag="7", name="app"),
        ],
    ),
    ProtoParser.ParserRuleResponse(
        name="Geo coordinate lookup response",
        # note on flowfilter: for tflow the port gets appended to the URL's host part
        filter="example\\.com.*/ReverseGeocode",
        field_definitions=[
            ProtoParser.ParserFieldDefinition(tag="1.2", name="address"),
            ProtoParser.ParserFieldDefinition(tag="1.3", name="address array element"),
            ProtoParser.ParserFieldDefinition(
                tag="1.3.1",
                name="unknown bytes",
                intended_decoding=ProtoParser.DecodedTypes.bytes,
            ),
            ProtoParser.ParserFieldDefinition(tag="1.3.2", name="element value long"),
            ProtoParser.ParserFieldDefinition(tag="1.3.3", name="element value short"),
            ProtoParser.ParserFieldDefinition(
                tag="",
                tag_prefixes=["1.5.1", "1.5.3", "1.5.4", "1.5.5", "1.5.6"],
                name="position",
            ),
            ProtoParser.ParserFieldDefinition(
                tag=".1",
                tag_prefixes=["1.5.1", "1.5.3", "1.5.4", "1.5.5", "1.5.6"],
                name="latitude",
                intended_decoding=ProtoParser.DecodedTypes.double,
            ),  # noqa: E501
            ProtoParser.ParserFieldDefinition(
                tag=".2",
                tag_prefixes=["1.5.1", "1.5.3", "1.5.4", "1.5.5", "1.5.6"],
                name="longitude",
                intended_decoding=ProtoParser.DecodedTypes.double,
            ),  # noqa: E501
            ProtoParser.ParserFieldDefinition(tag="7", name="app"),
        ],
    ),
]


class ViewGrpcWithRules(ViewGrpcProtobuf):
    name = "customized gRPC/protobuf"

    def __init__(self) -> None:
        super().__init__(config=config)

    def __call__(self, *args, **kwargs) -> contentviews.TViewResult:
        heading, lines = super().__call__(*args, **kwargs)
        return heading + " (addon with custom rules)", lines

    def render_priority(self, *args, **kwargs) -> float:
        # increase priority above default gRPC view
        s_prio = super().render_priority(*args, **kwargs)
        return s_prio + 1 if s_prio > 0 else s_prio


view = ViewGrpcWithRules()


def load(l):
    contentviews.add(view)


def done():
    contentviews.remove(view)