Add Github actions for unit and acceptance tests (#126)

.github/workflows/acceptance-tests.yml

+name: Acceptance tests
+
+on: [pull_request]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs: 
+ 
+  acceptance-tests:
+    runs-on: ubuntu-18.04
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Build and run docker image for cross compiling
+        run: |
+          cd test/artificial_samples
+          docker build -t cross_compiling .
+          docker run --rm -v $(pwd)/build:/home/cwe/artificial_samples/build cross_compiling sudo /home/cwe/.local/bin/scons
+      - uses: actions/setup-java@v1
+        with:
+          java-version: "11.0.x"
+          java-package: jdk
+          architecture: x64
+      - name: Install Ghidra
+        run: |
+          curl -fSL https://www.ghidra-sre.org/ghidra_9.2.1_PUBLIC_20201215.zip -o ghidra.zip
+          unzip -q ghidra.zip
+          mv ghidra_9.2.1_PUBLIC /opt/ghidra
+          rm ghidra.zip
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - name: Install cwe_checker
+        run: make all GHIDRA_PATH=/opt/ghidra
+      - uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --no-fail-fast -p acceptance_tests_ghidra -- --show-output --ignored --test-threads 1

.github/workflows/unit-tests.yml

+name: Unit tests
+
+on: [push]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - uses: actions-rs/cargo@v1
+        with:
+          command: test
\ No newline at end of file

Makefile

@@ -34,6 +34,11 @@ else
 	cargo test --no-fail-fast -p acceptance_tests_ghidra -- --show-output --ignored
 endif
 
+compile_test_files:
+	cd test/artificial_samples \
+	&& docker build -t cross_compiling . \
+	&& docker run --rm -v $(pwd)/build:/home/cwe/artificial_samples/build cross_compiling sudo /home/cwe/.local/bin/scons
+
 codestyle-check:
 	cargo fmt -- --check
 	cargo clippy -- -D clippy::all

cwe_checker_rs/src/checkers/cwe_243.rs

@@ -143,8 +143,12 @@ pub fn check_cwe(
                 if let Some(chdir_tid) =
                     find_symbol(&project.program, "chdir").map(|(tid, _)| tid.clone())
                 {
+                    if graph.neighbors(node).count() > 1 {
+                        panic!("Malformed Control flow graph: More than one edge for extern function call")
+                    }
+                    let chroot_return_to_node = graph.neighbors(node).next().unwrap();
                     // If chdir is called after chroot, we assume a secure chroot jail.
-                    if is_sink_call_reachable_from_source_call(graph, node, &chroot_tid, &chdir_tid)
+                    if is_sink_call_reachable_from_source_call(graph, chroot_return_to_node, &chroot_tid, &chdir_tid)
                         .is_none()
                     {
                         // If chdir is not called after chroot, it has to be called before it.

test/artificial_samples/Dockerfile

+FROM ubuntu:xenial
+
+RUN apt-get -y update \
+    && apt-get install -y sudo \
+    && useradd -m cwe \
+    && echo "cwe:cwe" | chpasswd \
+    && adduser cwe sudo \
+    && sed -i.bkp -e 's/%sudo\s\+ALL=(ALL\(:ALL\)\?)\s\+ALL/%sudo ALL=NOPASSWD:ALL/g' /etc/sudoers
+    
+USER cwe
+
+RUN sudo apt-get install python-pip apt-utils -y
+
+RUN pip install --upgrade pip
+
+RUN pip install scons
+
+ENV PATH="/home/cwe/.local/bin/:${PATH}"
+
+COPY . /home/cwe/artificial_samples/
+
+WORKDIR /home/cwe/artificial_samples/
+
+RUN ./install_cross_compilers.sh
+
+# RUN sudo /home/cwe/.local/bin/scons
\ No newline at end of file

test/artificial_samples/Readme.md

+# Test binaries for the acceptance test suite
+
+For the acceptance test suite of the *cwe_checker*,
+the C-files inside this directory have to be compiled for a variety of CPU architectures and C-compilers.
+The provided dockerfile should be used for the build process.
+
+## Prerequisites
+
+- Have Docker installed on your system
+
+## Build commands
+
+Inside this directory run the following commands:
+```shell
+docker build -t cross_compiling .
+docker run --rm -v $(pwd)/build:/home/cwe/artificial_samples/build cross_compiling sudo /home/cwe/.local/bin/scons
+```
+