feat: Verify agent checksum (#79)

The action now verifies the checksum after downloading the agent. Notable changes: - Replaced the input `_local-agent-path` with the environment variable `_LOCAL_AGENT`. - Both the local and downloaded agents are now installed at the same location (`/opt/bullfrog/agent`).
bullfrogsec · Jul 21, 2024 · e5b087d · e5b087d
1 parent 0247bcb
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Showing 16 changed files with 235 additions and 112 deletions.
diff --git a/.github/workflows/bullfrog.yml b/.github/workflows/bullfrog.yml
@@ -40,18 +40,18 @@ jobs:
  with:
  egress-policy: block
  allowed-domains: |
- registry.npmjs.org
+ *.blob.core.windows.net
+ *.docker.io
  *.golang.org
- storage.googleapis.com
  *.github.com
- *.blob.core.windows.net
+ deb.debian.org
+ production.cloudflare.docker.com
+ registry.npmjs.org
+ storage.googleapis.com
 
  - name: Checkout
  uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
 
- - name: Install deps
- run: sudo apt-get install libnetfilter-queue-dev
-
  - name: Build
  run: |
  make bootstrap
@@ -68,7 +68,7 @@ jobs:
  agent/agent
  action/dist
 
- check-dist-diff:
+ check-artifacts:
  needs: build
  runs-on: ubuntu-22.04
  timeout-minutes: 5
@@ -88,9 +88,9 @@ jobs:
  with:
  name: build-artifacts
 
- - name: Check if dist has changed for the action/dist folder
+ - name: Check Artifact Build
  run: |
- git diff --exit-code --quiet action/dist || (echo "action/dist has changed, please commit the changes" && exit 1)
+ make test.artifacts
 
  test-audit:
  needs: build
@@ -107,10 +107,11 @@ jobs:
 
  - name: Enable egress filtering
  uses: ./
+ env:
+ _LOCAL_AGENT: true
  with:
  allowed-domains: |
  *.google.com
- _local-agent-path: agent/agent
 
  - name: Make HTTP requests
  run: |
@@ -137,12 +138,13 @@ jobs:
 
  - name: Enable egress filtering
  uses: ./
+ env:
+ _LOCAL_AGENT: true
  with:
  allowed-domains: |
  *.google.com
  egress-policy: block
  enable-sudo: false
- _local-agent-path: agent/agent
 
  - name: Make HTTP requests
  run: source test/make_http_requests.sh
@@ -168,12 +170,13 @@ jobs:
 
  - name: Enable egress filtering
  uses: ./
+ env:
+ _LOCAL_AGENT: true
  with:
  allowed-domains: |
  *.google.com
  dns-policy: any
  egress-policy: block
- _local-agent-path: agent/agent
 
  - name: Make HTTP requests
  run: source test/make_http_requests.sh
@@ -198,16 +201,16 @@ jobs:
 
  - name: Enable egress filtering
  uses: ./
+ env:
+ _LOCAL_AGENT: true
  with:
  allowed-ips: |
  172.17.0.0/16
  allowed-domains: |
- production.cloudflare.docker.com
- docker.io
  *.docker.io
+ production.cloudflare.docker.com
  www.google.com
  egress-policy: block
- _local-agent-path: agent/agent
 
  - name: Test curl calls within Docker
  run: |
@@ -249,6 +252,7 @@ jobs:
  download.docker.com
  go.dev
  objects.githubusercontent.com
+ packages.microsoft.com
  vagrantcloud-files-production.s3-accelerate.amazonaws.com
  vagrantcloud.com
  www.google.com
@@ -262,6 +266,7 @@ jobs:
 
  - name: Install Dependencies
  run: |
+ sudo apt-get update
  sudo apt-get install --yes vagrant virtualbox
 
  - name: Start VM
@@ -309,7 +314,7 @@ jobs:
  needs:
  [
  build,
- check-dist-diff,
+ check-artifacts,
  test-audit,
  test-block,
  test-block-but-allow-any-dns-requests,

diff --git a/Makefile b/Makefile
@@ -30,6 +30,17 @@ test.integration: test.integration.block
 test.integration.block:
  vagrant ssh --command "bash /vagrant/test/block.sh"
 
+.PHONY: test.artifacts
+test.artifacts: test.artifacts.action test.artifacts.agent
+
+.PHONY: test.artifacts.action
+test.artifacts.action:
+ cd $(ACTION_DIRECTORY) && make test.artifacts
+
+.PHONY: test.artifacts.agent
+test.artifacts.agent:
+ cd $(AGENT_DIRECTORY) && make test.artifacts
+
 .PHONY: test.lint
 test.lint: test.lint.action test.lint.agent
 

diff --git a/action.yml b/action.yml
@@ -32,11 +32,6 @@ inputs:
  type: string
  default: ${{ runner.temp }}/agent-logs
 
- _local-agent-path:
- description: "(Internal) Path to a local agent binary to use instead of fetching it from Github. This is useful for testing changes to the agent without releasing it. The path is relative to the root action directory (where this action.yml is located)."
- type: string
- default: ""
-
 runs:
  using: "node20"
  main: "action/dist/main.js"

diff --git a/action/Makefile b/action/Makefile
@@ -13,6 +13,10 @@ build:
 fix:
  npx eslint --fix .
 
+.PHONY: test.artifacts
+test.artifacts:
+ git diff --exit-code --quiet dist || (echo "dist has changed, please commit the changes" && exit 1)
+
 .PHONY: test.lint
 test.lint:
  npx eslint .

diff --git a/action/dist/main.js b/action/dist/main.js
@@ -19015,14 +19015,15 @@ function parseInputs() {
  if (dnsPolicy !== ALLOWED_DOMAINS_ONLY && dnsPolicy !== ANY) {
  throw new Error(`dns-policy must be '${ALLOWED_DOMAINS_ONLY}' or '${ANY}'`);
  }
+ const localAgent = process.env["_LOCAL_AGENT"]?.toLowerCase() === "true";
  return {
  allowedDomains,
  allowedIps,
  dnsPolicy,
  enableSudo: core.getBooleanInput("enable-sudo"),
  egressPolicy,
+ localAgent,
  logDirectory: core.getInput("_log-directory", { required: true }),
- localAgentPath: core.getInput("_local-agent-path"),
  agentDownloadBaseURL: core.getInput("_agent-download-base-url")
  };
 }
@@ -19067,6 +19068,54 @@ async function waitForStringInFile({
 
 // src/main.ts
 var exec = import_node_util.default.promisify(import_node_child_process.exec);
+async function copyLocalAgent({ agentDirectory }) {
+ await import_promises3.default.mkdir(import_node_path.default.dirname(AGENT_INSTALL_PATH), { recursive: true });
+ await import_promises3.default.cp(import_node_path.default.join(agentDirectory, "agent"), AGENT_INSTALL_PATH);
+}
+async function downloadAgent({
+ actionDirectory,
+ agentDirectory,
+ version: version2,
+ agentDownloadBaseURL
+}) {
+ console.log(`Downloading agent v${version2}`);
+ const { status } = (0, import_node_child_process.spawnSync)(
+ "bash",
+ [
+ import_node_path.default.join(actionDirectory, "scripts", "download_agent.sh"),
+ `v${version2}`,
+ agentDownloadBaseURL
+ ],
+ {
+ env: {
+ AGENT_DIRECTORY: agentDirectory
+ },
+ stdio: "inherit"
+ }
+ );
+ if (status !== 0) {
+ throw new Error("Couldn't download agent");
+ }
+}
+async function installAgent({
+ actionDirectory,
+ agentDirectory,
+ localAgent,
+ version: version2,
+ agentDownloadBaseURL
+}) {
+ if (localAgent) {
+ await copyLocalAgent({ agentDirectory });
+ } else {
+ await downloadAgent({
+ actionDirectory,
+ agentDirectory,
+ agentDownloadBaseURL,
+ version: version2
+ });
+ }
+ await verifyAgent({ agentDirectory });
+}
 function installPackages() {
  console.log("Installing packages");
  const { status } = (0, import_node_child_process.spawnSync)(
@@ -19124,35 +19173,8 @@ async function startTetragon({
  });
  console.timeEnd("Tetragon startup time");
 }
-async function downloadAgent({
- actionDirectory,
- localAgentPath,
- version: version2,
- agentDownloadBaseURL
-}) {
- if (localAgentPath !== "") {
- const absolutePath = import_node_path.default.join(actionDirectory, "..", localAgentPath);
- core3.debug(`Using local agent from ${absolutePath}`);
- return absolutePath;
- }
- console.log(`Downloading agent v${version2}`);
- const { status } = (0, import_node_child_process.spawnSync)(
- "bash",
- [
- import_node_path.default.join(actionDirectory, "scripts", "download_agent.sh"),
- `v${version2}`,
- agentDownloadBaseURL
- ],
- { stdio: "inherit" }
- );
- if (status !== 0) {
- throw new Error("Couldn't download agent");
- }
- return AGENT_INSTALL_PATH;
-}
 async function startAgent({
  agentDirectory,
- agentPath,
  agentLogFilepath,
  allowedDomains,
  allowedIps,
@@ -19175,14 +19197,14 @@ async function startAgent({
  console.log("loaded audit rules");
  }
  const agentOut = await import_promises3.default.open(agentLogFilepath, "a");
- console.log(`Starting agent from ${agentPath}`);
+ console.log(`Starting agent from ${AGENT_INSTALL_PATH}`);
  console.time("Agent startup time");
- await exec(`sudo chmod +x ${agentPath}`);
+ await exec(`sudo chmod +x ${AGENT_INSTALL_PATH}`);
  const allowedDomainsFlag = allowedDomains.length > 0 ? `--allowed-domains ${allowedDomains.join(",")}` : "";
  const allowedIpsFlag = allowedIps.length > 0 ? `--allowed-ips ${allowedIps.join(",")}` : "";
  const enableSudoFlag = enableSudo ? "true" : "false";
  const agentCommand = [
- agentPath,
+ AGENT_INSTALL_PATH,
  "--dns-policy",
  dnsPolicy,
  "--egress-policy",
@@ -19202,6 +19224,15 @@ async function startAgent({
  }
  console.timeEnd("Agent startup time");
 }
+async function verifyAgent({ agentDirectory }) {
+ const agentDirName = import_node_path.default.dirname(AGENT_INSTALL_PATH);
+ const src = import_node_path.default.join(agentDirectory, "agent.sha256");
+ const dest = import_node_path.default.join(agentDirName, "agent.sha256");
+ await import_promises3.default.cp(src, dest);
+ await exec("sha256sum --check --strict agent.sha256", {
+ cwd: agentDirName
+ });
+}
 async function main() {
  const {
  agentDownloadBaseURL,
@@ -19210,7 +19241,7 @@ async function main() {
  dnsPolicy,
  egressPolicy,
  enableSudo,
- localAgentPath,
+ localAgent,
  logDirectory
  } = parseInputs();
  const actionDirectory = import_node_path.default.join(__dirname, "..");
@@ -19224,15 +19255,15 @@ async function main() {
  await startTetragon({
  tetragonLogFilepath
  });
- const agentPath = await downloadAgent({
+ await installAgent({
  actionDirectory,
- localAgentPath,
+ agentDirectory,
+ localAgent,
  version: pkg.version,
  agentDownloadBaseURL
  });
  await startAgent({
  agentLogFilepath,
- agentPath,
  agentDirectory,
  allowedDomains,
  allowedIps,

diff --git a/action/dist/main.js.map b/action/dist/main.js.map
diff --git a/action/dist/post.js b/action/dist/post.js
@@ -19013,14 +19013,15 @@ function parseInputs() {
  if (dnsPolicy !== ALLOWED_DOMAINS_ONLY && dnsPolicy !== ANY) {
  throw new Error(`dns-policy must be '${ALLOWED_DOMAINS_ONLY}' or '${ANY}'`);
  }
+ const localAgent = process.env["_LOCAL_AGENT"]?.toLowerCase() === "true";
  return {
  allowedDomains,
  allowedIps,
  dnsPolicy,
  enableSudo: core.getBooleanInput("enable-sudo"),
  egressPolicy,
+ localAgent,
  logDirectory: core.getInput("_log-directory", { required: true }),
- localAgentPath: core.getInput("_local-agent-path"),
  agentDownloadBaseURL: core.getInput("_agent-download-base-url")
  };
 }

diff --git a/action/dist/post.js.map b/action/dist/post.js.map
diff --git a/action/scripts/download_agent.sh b/action/scripts/download_agent.sh
@@ -16,6 +16,7 @@ if [ -f "$AGENT_FILE" ]; then
 else
  curl -L ${DOWNLOAD_URL}/${VERSION}/agent.tar.gz -o "$AGENT_FILE"
 fi
+
 tar -xvf "$AGENT_FILE" -C $TMP_DIR
 
 mkdir -p "$FINAL_BIN_DIR"

diff --git a/action/src/inputs.ts b/action/src/inputs.ts
@@ -10,8 +10,8 @@ export interface Inputs {
  dnsPolicy: DnsPolicy;
  enableSudo: boolean;
  egressPolicy: EgressPolicy;
+ localAgent: boolean;
  logDirectory: string;
- localAgentPath: string;
  agentDownloadBaseURL: string;
 }
 
@@ -59,14 +59,16 @@ export function parseInputs(): Inputs {
  throw new Error(`dns-policy must be '${ALLOWED_DOMAINS_ONLY}' or '${ANY}'`);
  }
 
+ const localAgent = process.env["_LOCAL_AGENT"]?.toLowerCase() === "true";
+
  return {
  allowedDomains,
  allowedIps,
  dnsPolicy,
  enableSudo: core.getBooleanInput("enable-sudo"),
  egressPolicy,
+ localAgent,
  logDirectory: core.getInput("_log-directory", { required: true }),
- localAgentPath: core.getInput("_local-agent-path"),
  agentDownloadBaseURL: core.getInput("_agent-download-base-url"),
  };
 }