{Packaging} Harden cross-platform launchers against CWD imports

scripts/curl_install_pypi/install.py

@@ -26,7 +26,7 @@
 from urllib.request import urlopen
 
 AZ_DISPATCH_TEMPLATE = """#!/usr/bin/env bash
-{install_dir}/bin/python -m azure.cli "$@"
+{install_dir}/bin/python -c 'import os, runpy, sys; cwd = os.path.normcase(os.path.realpath(os.getcwd())); sys.path[:] = [path for path in sys.path if os.path.normcase(os.path.realpath(path or os.curdir)) != cwd]; runpy.run_module("azure.cli.__main__", run_name="__main__", alter_sys=True)' "$@"
 """
 
 VIRTUALENV_VERSION = '16.7.11'

scripts/release/macos/templates/az_launcher.sh.in

@@ -62,4 +62,4 @@ fi
 
 export PYTHONPATH="$AZURE_CLI_SITE_PACKAGES"
 export AZ_INSTALLER="$INSTALLER"
-exec "$PYTHON" -sm azure.cli "$@"
+exec "$PYTHON" -s "$AZURE_CLI_SITE_PACKAGES/azure/cli/__main__.py" "$@"

scripts/release/rpm/azure-cli.spec

@@ -74,7 +74,8 @@ printf "#!/usr/bin/env bash
 bin_dir=\`cd \"\$(dirname \"\$BASH_SOURCE[0]\")\"; pwd\`
 python_cmd=%{python_cmd}
 if command -v ${python_version} &>/dev/null; then python_cmd=${python_version}; fi
-AZ_INSTALLER=RPM PYTHONPATH=\"\$bin_dir/../lib64/az/lib/${python_version}/site-packages\" \$python_cmd -sm azure.cli \"\$@\"
+site_packages=\"\$bin_dir/../lib64/az/lib/${python_version}/site-packages\"
+AZ_INSTALLER=RPM PYTHONPATH=\"\$site_packages\" \$python_cmd -s \"\$site_packages/azure/cli/__main__.py\" \"\$@\"
 " > %{buildroot}%{_bindir}/az
 rm %{buildroot}%{cli_lib_dir}/bin/python* %{buildroot}%{cli_lib_dir}/bin/pip*
 

scripts/release/tests/test_launcher_security.py

@@ -0,0 +1,131 @@
+# --------------------------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for license information.
+# --------------------------------------------------------------------------------------------
+
+import os
+from pathlib import Path
+import runpy
+import shutil
+import subprocess
+import sys
+import tempfile
+import unittest
+
+
+REPO_ROOT = Path(__file__).resolve().parents[3]
+MACOS_LAUNCHER = REPO_ROOT / 'scripts/release/macos/templates/az_launcher.sh.in'
+CURL_INSTALLER = REPO_ROOT / 'scripts/curl_install_pypi/install.py'
+
+
+class LauncherSecurityTest(unittest.TestCase):
+
+    def _write_cli_package(self, site_packages, exit_code):
+        cli_dir = site_packages / 'azure' / 'cli'
+        cli_dir.mkdir(parents=True)
+        (cli_dir.parent / '__init__.py').write_text('', encoding='utf-8')
+        (cli_dir / '__init__.py').write_text('', encoding='utf-8')
+        (cli_dir / '__main__.py').write_text(
+            'import json, sys\n'
+            'print(json.dumps(sys.argv[1:]))\n'
+            f'raise SystemExit({exit_code})\n',
+            encoding='utf-8',
+        )
+
+    def _write_attacker_module(self, attacker_dir):
+        attacker_dir.mkdir()
+        (attacker_dir / 'azure.py').write_text(
+            'from pathlib import Path\n'
+            'Path("PWNED").write_text("yes", encoding="utf-8")\n',
+            encoding='utf-8',
+        )
+
+    def test_macos_launcher_ignores_cwd_module(self):
+        with tempfile.TemporaryDirectory() as temp_dir:
+            root = Path(temp_dir)
+            install_dir = root / 'install'
+            launcher_dir = install_dir / 'libexec' / 'bin'
+            site_packages = install_dir / 'libexec' / 'lib' / \
+                f'python{sys.version_info.major}.{sys.version_info.minor}' / 'site-packages'
+            attacker_dir = root / 'attacker'
+            launcher_dir.mkdir(parents=True)
+            self._write_cli_package(site_packages, exit_code=23)
+            self._write_attacker_module(attacker_dir)
+
+            launcher = launcher_dir / 'az'
+            launcher.write_text(
+                MACOS_LAUNCHER.read_text(encoding='utf-8')
+                .replace('{PYTHON_MAJOR_MINOR}', f'{sys.version_info.major}.{sys.version_info.minor}')
+                .replace('{PYTHON_BIN}', f'python{sys.version_info.major}'),
+                encoding='utf-8',
+            )
+            launcher.chmod(0o755)
+
+            result = subprocess.run(
+                [str(launcher), 'alpha', 'two words'],
+                cwd=attacker_dir,
+                env={**os.environ, 'AZ_PYTHON': sys.executable},
+                check=False,
+                capture_output=True,
+                text=True,
+            )
+
+            self.assertEqual(23, result.returncode, result.stderr)
+            self.assertEqual('["alpha", "two words"]', result.stdout.strip())
+            self.assertFalse((attacker_dir / 'PWNED').exists())
+
+    def test_curl_dispatch_ignores_cwd_module(self):
+        with tempfile.TemporaryDirectory() as temp_dir:
+            root = Path(temp_dir)
+            install_dir = root / 'install'
+            bin_dir = install_dir / 'bin'
+            site_packages = install_dir / 'site-packages'
+            attacker_dir = root / 'attacker'
+            bin_dir.mkdir(parents=True)
+            self._write_cli_package(site_packages, exit_code=31)
+            self._write_attacker_module(attacker_dir)
+
+            python_wrapper = bin_dir / 'python'
+            python_wrapper.write_text(
+                '#!/usr/bin/env bash\n'
+                f'PYTHONPATH="{site_packages}" exec "{sys.executable}" "$@"\n',
+                encoding='utf-8',
+            )
+            python_wrapper.chmod(0o755)
+
+            dispatch_template = runpy.run_path(str(CURL_INSTALLER))['AZ_DISPATCH_TEMPLATE']
+            launcher = root / 'az'
+            launcher.write_text(dispatch_template.format(install_dir=install_dir), encoding='utf-8')
+            launcher.chmod(0o755)
+
+            result = subprocess.run(
+                [str(launcher), 'alpha', 'two words'],
+                cwd=attacker_dir,
+                check=False,
+                capture_output=True,
+                text=True,
+            )
+
+            self.assertEqual(31, result.returncode, result.stderr)
+            self.assertEqual('["alpha", "two words"]', result.stdout.strip())
+            self.assertFalse((attacker_dir / 'PWNED').exists())
+
+    def test_production_launchers_do_not_use_unsafe_module_entry(self):
+        launcher_paths = [
+            REPO_ROOT / 'src/azure-cli/az.bat',
+            REPO_ROOT / 'src/azure-cli/azps.ps1',
+            REPO_ROOT / 'scripts/curl_install_pypi/install.py',
+            REPO_ROOT / 'scripts/release/macos/templates/az_launcher.sh.in',
+            REPO_ROOT / 'scripts/release/rpm/azure-cli.spec',
+            REPO_ROOT / 'src/azure-cli/azure/cli/command_modules/cognitiveservices/custom.py',
+        ]
+
+        for launcher_path in launcher_paths:
+            with self.subTest(launcher_path=launcher_path):
+                contents = launcher_path.read_text(encoding='utf-8')
+                self.assertNotIn('-m azure.cli', contents)
+                self.assertNotIn("'-m', 'azure.cli'", contents)
+
+
+if __name__ == '__main__':
+    unittest.main()

src/azure-cli/az.bat

@@ -1,11 +1,15 @@
 @echo off
 setlocal
 
-SET PYTHONPATH=%~dp0\src;%PYTHONPATH%
-SET AZ_INSTALLER=PIP
+IF EXIST "%~dp0src\azure\cli\__main__.py" (
+  SET "PYTHONPATH=%~dp0src;%PYTHONPATH%"
+) ELSE (
+  SET "PYTHONPATH=%~dp0;%PYTHONPATH%"
+)
+SET "AZ_INSTALLER=PIP"
 
 IF EXIST "%~dp0\python.exe" (
-  "%~dp0\python.exe" -m azure.cli %*
+  "%~dp0\python.exe" -c "import os,runpy,sys; cwd=os.path.normcase(os.path.realpath(os.getcwd())); sys.path[:]=[path for path in sys.path if os.path.normcase(os.path.realpath(path or os.curdir)) != cwd]; runpy.run_module('azure.cli.__main__', run_name='__main__', alter_sys=True)" %*
 ) ELSE (
-  python -m azure.cli %*
+  python -c "import os,runpy,sys; cwd=os.path.normcase(os.path.realpath(os.getcwd())); sys.path[:]=[path for path in sys.path if os.path.normcase(os.path.realpath(path or os.curdir)) != cwd]; runpy.run_module('azure.cli.__main__', run_name='__main__', alter_sys=True)" %*
 )

src/azure-cli/azps.ps1

@@ -1,13 +1,22 @@
 $env:AZ_INSTALLER="PIP"
+$moduleSearchPath = if (Test-Path "$PSScriptRoot\src\azure\cli\__main__.py") {
+    "$PSScriptRoot\src"
+}
+else {
+    $PSScriptRoot
+}
+$env:PYTHONPATH = "$moduleSearchPath$([IO.Path]::PathSeparator)$env:PYTHONPATH"
+$launcherCode = 'import os,runpy,sys; cwd=os.path.normcase(os.path.realpath(os.getcwd())); sys.path[:]=[path for path in sys.path if os.path.normcase(os.path.realpath(path or os.curdir)) != cwd]; runpy.run_module("azure.cli.__main__", run_name="__main__", alter_sys=True)'
 
 if (Test-Path "$PSScriptRoot\python.exe") {
-    # Perfer python.exe in venv
-    & "$PSScriptRoot\python.exe" -m azure.cli $args
+    # Prefer python.exe in venv
+    & "$PSScriptRoot\python.exe" -c $launcherCode $args
 }
 else {
     # Run system python.exe
-    python.exe -m azure.cli $args
+    python.exe -c $launcherCode $args
 }
+exit $LASTEXITCODE
 
 # SIG # Begin signature block
 # MIInqgYJKoZIhvcNAQcCoIInmzCCJ5cCAQExDzANBglghkgBZQMEAgEFADB5Bgor

src/azure-cli/azure/cli/command_modules/cognitiveservices/custom.py

@@ -765,11 +765,8 @@ def _push_image_to_registry(_cmd, image_name, registry_name):  # pylint: disable
 
     try:
         # Login to ACR using Azure CLI credentials
-        # We use sys.executable + '-m azure.cli' instead of 'az' command to ensure
-        # compatibility when developing/testing the CLI from source. In development
-        # environments, 'az' may not be in PATH or may point to a different installation.
-        # In production, sys.executable will still correctly invoke the installed CLI.
-        az_cmd = [sys.executable, '-m', 'azure.cli', 'acr', 'login', '--name', registry_name]
+        azure_cli_main = Path(__file__).resolve().parents[2] / '__main__.py'
+        az_cmd = [sys.executable, str(azure_cli_main), 'acr', 'login', '--name', registry_name]
         logger.info("Logging into ACR: %s", registry_name)
 
         result = subprocess.run(