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Merged
mhils merged 1 commit into from
Apr 29, 2025
Merged

make protobuf parsing more forgiving #254

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1 change: 1 addition & 0 deletions CHANGELOG.md
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Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
## Unreleased: mitmproxy_rs next

- Make gRPC and Protobuf parsing more forgiving.

## 29 April 2025: mitmproxy_rs 0.12.1

Expand Down
169 changes: 103 additions & 66 deletions mitmproxy-contentviews/src/protobuf/view_grpc.rs
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Original file line number Diff line number Diff line change
@@ -1,7 +1,9 @@
use super::{existing_proto_definitions, reencode};
use crate::protobuf::existing_proto_definitions::DescriptorWithDeps;
use crate::{Metadata, Prettify, Protobuf, Reencode};
use anyhow::{bail, Context, Result};
use flate2::read::{DeflateDecoder, GzDecoder};
use log::info;
use mitmproxy_highlight::Language;
use serde::Deserialize;
use serde_yaml::Value;
Expand All @@ -18,11 +20,39 @@ impl Prettify for GRPC {
Language::Yaml
}

fn prettify(&self, mut data: &[u8], metadata: &dyn Metadata) -> Result<String> {
let mut protos = vec![];
fn prettify(&self, data: &[u8], metadata: &dyn Metadata) -> Result<String> {
let encoding = metadata.get_header("grpc-encoding").unwrap_or_default();
let proto_def = existing_proto_definitions::find_best_match(metadata)?;
if let Some(descriptor) = &proto_def {
if let Ok(ret) = self.prettify_with_descriptor(data, &encoding, descriptor) {
return Ok(ret);
}
}
let ret = self.prettify_with_descriptor(data, &encoding, &DescriptorWithDeps::default())?;
if proto_def.is_some() {
info!("Existing gRPC definition does not match, parsing as unknown proto.");
}
Ok(ret)
}

let descriptor = existing_proto_definitions::find_best_match(metadata)?.unwrap_or_default();
fn render_priority(&self, _data: &[u8], metadata: &dyn Metadata) -> f32 {
match metadata.content_type() {
Some("application/grpc") => 1.0,
Some("application/grpc+proto") => 1.0,
Some("application/prpc") => 1.0,
_ => 0.0,
}
}
}

impl GRPC {
fn prettify_with_descriptor(
&self,
mut data: &[u8],
encoding: &str,
descriptor: &DescriptorWithDeps,
) -> Result<String> {
let mut protos = vec![];
while !data.is_empty() {
let compressed = match data[0] {
0 => false,
Expand All @@ -39,8 +69,7 @@ impl Prettify for GRPC {

let mut decompressed = Vec::new();
let proto = if compressed {
let encoding = metadata.get_header("grpc-encoding").unwrap_or_default();
match encoding.as_str() {
match encoding {
"deflate" => {
let mut decoder = DeflateDecoder::new(proto);
decoder.read_to_end(&mut decompressed)?;
Expand All @@ -57,21 +86,12 @@ impl Prettify for GRPC {
} else {
proto
};
protos.push(Protobuf.prettify_with_descriptor(proto, &descriptor)?);
protos.push(Protobuf.prettify_with_descriptor(proto, descriptor)?);
data = &data[5 + len..];
}

Ok(protos.join("\n---\n\n"))
}

fn render_priority(&self, _data: &[u8], metadata: &dyn Metadata) -> f32 {
match metadata.content_type() {
Some("application/grpc") => 1.0,
Some("application/grpc+proto") => 1.0,
Some("application/prpc") => 1.0,
_ => 0.0,
}
}
}

impl Reencode for GRPC {
Expand All @@ -97,7 +117,6 @@ mod tests {
use crate::test::TestMetadata;

const TEST_YAML: &str = "1: 150\n\n---\n\n1: 150\n";
const TEST_YAML_KNOWN: &str = "example: 150\n\n---\n\nexample: 150\n";
const TEST_GRPC: &[u8] = &[
0, 0, 0, 0, 3, 8, 150, 1, // first message
0, 0, 0, 0, 3, 8, 150, 1, // second message
Expand Down Expand Up @@ -164,63 +183,81 @@ mod tests {
);
}

#[test]
fn test_existing_proto() {
let metadata = TestMetadata::default().with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/simple.proto"
));
let res = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(res, TEST_YAML_KNOWN);
}
mod existing_definition {
use super::*;

#[test]
fn test_existing_service_request() {
let metadata = TestMetadata::default()
.with_is_http_request(true)
.with_path("/Service/Method")
.with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/simple_service.proto"
));
let req = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(req, TEST_YAML);
}
const TEST_YAML_KNOWN: &str = "example: 150\n\n---\n\nexample: 150\n";

#[test]
fn test_existing_service_response() {
let metadata = TestMetadata::default()
.with_is_http_request(false)
.with_path("/Service/Method")
.with_protobuf_definitions(concat!(
#[test]
fn existing_proto() {
let metadata = TestMetadata::default().with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/simple_service.proto"
"/testdata/protobuf/simple.proto"
));
let req = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(req, TEST_YAML_KNOWN);
}
let res = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(res, TEST_YAML_KNOWN);
}

#[test]
fn test_existing_package() {
let metadata = TestMetadata::default()
.with_path("/example.simple.Service/Method")
.with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/simple_package.proto"
));
let req = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(req, TEST_YAML_KNOWN);
}
#[test]
fn existing_service_request() {
let metadata = TestMetadata::default()
.with_is_http_request(true)
.with_path("/Service/Method")
.with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/simple_service.proto"
));
let req = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(req, TEST_YAML);
}

#[test]
fn test_existing_nested() {
let metadata = TestMetadata::default()
.with_path("/example.nested.Service/Method")
.with_protobuf_definitions(concat!(
#[test]
fn existing_service_response() {
let metadata = TestMetadata::default()
.with_is_http_request(false)
.with_path("/Service/Method")
.with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/simple_service.proto"
));
let req = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(req, TEST_YAML_KNOWN);
}

#[test]
fn existing_package() {
let metadata = TestMetadata::default()
.with_path("/example.simple.Service/Method")
.with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/simple_package.proto"
));
let req = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(req, TEST_YAML_KNOWN);
}

#[test]
fn existing_nested() {
let metadata = TestMetadata::default()
.with_path("/example.nested.Service/Method")
.with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/nested.proto"
));
let req = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(req, TEST_YAML_KNOWN);
}

/// When the existing proto definition does not match the wire data,
/// but the wire data is still valid Protobuf, parse it raw.
#[test]
fn existing_mismatch() {
let metadata = TestMetadata::default().with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/nested.proto"
"/testdata/protobuf/mismatch.proto"
));
let req = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(req, TEST_YAML_KNOWN);
let res = GRPC.prettify(TEST_GRPC, &metadata).unwrap();
assert_eq!(res, TEST_YAML);
}
}
}
20 changes: 16 additions & 4 deletions mitmproxy-contentviews/src/protobuf/view_protobuf.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@ use crate::protobuf::{
};
use crate::{Metadata, Prettify, Reencode};
use anyhow::{Context, Result};
use log::info;
use mitmproxy_highlight::Language;
use serde_yaml::Value;

Expand Down Expand Up @@ -37,8 +38,17 @@ impl Prettify for Protobuf {
}

fn prettify(&self, data: &[u8], metadata: &dyn Metadata) -> Result<String> {
let descriptor = existing_proto_definitions::find_best_match(metadata)?.unwrap_or_default();
self.prettify_with_descriptor(data, &descriptor)
let proto_def = existing_proto_definitions::find_best_match(metadata)?;
if let Some(descriptor) = &proto_def {
if let Ok(ret) = self.prettify_with_descriptor(data, descriptor) {
return Ok(ret);
}
}
let ret = self.prettify_with_descriptor(data, &DescriptorWithDeps::default())?;
if proto_def.is_some() {
info!("Existing protobuf definition does not match, parsing as unknown proto.");
}
Ok(ret)
}

fn render_priority(&self, _data: &[u8], metadata: &dyn Metadata) -> f32 {
Expand Down Expand Up @@ -210,14 +220,16 @@ mod tests {
assert_eq!(result, VARINT_PRETTY_YAML);
}

/// When the existing proto definition does not match the wire data,
/// but the wire data is still valid Protobuf, parse it raw.
#[test]
fn prettify_mismatch() {
let metadata = TestMetadata::default().with_protobuf_definitions(concat!(
env!("CARGO_MANIFEST_DIR"),
"/testdata/protobuf/simple.proto"
));
let result = Protobuf.prettify(string::PROTO, &metadata);
assert!(result.is_err());
let result = Protobuf.prettify(string::PROTO, &metadata).unwrap();
assert_eq!(result, string::YAML);
}

#[test]
Expand Down
5 changes: 5 additions & 0 deletions mitmproxy-contentviews/testdata/protobuf/mismatch.proto
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Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
syntax = "proto3";

message TestMessage {
string example = 1;
}
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