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Safer Shell command Execution (#4795) 

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: N. Taylor Mullen <ntaylormullen@google.com>
This commit is contained in:
matt korwel 2025-07-25 12:25:32 -07:00 committed by GitHub
parent 7ddbf97634
commit 820105e982
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GPG Key ID: B5690EEEBB952194
6 changed files with 975 additions and 559 deletions
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22
esbuild.config.js
View File

@ -33,5 +33,27 @@ esbuild
banner: { banner: {
js: `import { createRequire } from 'module'; const require = createRequire(import.meta.url); globalThis.__filename = require('url').fileURLToPath(import.meta.url); globalThis.__dirname = require('path').dirname(globalThis.__filename);`, js: `import { createRequire } from 'module'; const require = createRequire(import.meta.url); globalThis.__filename = require('url').fileURLToPath(import.meta.url); globalThis.__dirname = require('path').dirname(globalThis.__filename);`,
}, },
external: [
'es-toolkit/compat',
'ansi-escapes',
'auto-bind',
'command-exists',
'@babel/code-frame',
'cli-truncate',
'cli-cursor',
'@alcalzone/ansi-tokenize',
'cli-boxes',
'code-excerpt',
'chalk',
'cli-spinners',
'configstore',
'gradient-string',
'devlop',
'escape-goat',
'@iarna/toml',
'@pnpm/npm-conf',
'deep-extend',
'ansi-align',
],
}) })
.catch(() => process.exit(1)); .catch(() => process.exit(1));

9
packages/cli/src/ui/components/messages/ToolConfirmationMessage.tsx
View File

@ -132,19 +132,20 @@ export const ToolConfirmationMessage: React.FC<
const executionProps = const executionProps =
confirmationDetails as ToolExecuteConfirmationDetails; confirmationDetails as ToolExecuteConfirmationDetails;
question = `Allow execution?`; question = `Allow execution of: '${executionProps.rootCommand}'?`;
options.push( options.push(
{ {
label: 'Yes, allow once', label: `Yes, allow once`,
value: ToolConfirmationOutcome.ProceedOnce, value: ToolConfirmationOutcome.ProceedOnce,
}, },
{ {
label: `Yes, allow always "${executionProps.rootCommand} ..."`, label: `Yes, allow always ...`,
value: ToolConfirmationOutcome.ProceedAlways, value: ToolConfirmationOutcome.ProceedAlways,
}, },
{ label: 'No (esc)', value: ToolConfirmationOutcome.Cancel },
); );
options.push({ label: 'No (esc)', value: ToolConfirmationOutcome.Cancel });
let bodyContentHeight = availableBodyContentHeight(); let bodyContentHeight = availableBodyContentHeight();
if (bodyContentHeight !== undefined) { if (bodyContentHeight !== undefined) {
bodyContentHeight -= 2; // Account for padding; bodyContentHeight -= 2; // Account for padding;

420
packages/core/src/tools/shell.test.ts
View File

@ -9,397 +9,9 @@ import { ShellTool } from './shell.js';
import { Config } from '../config/config.js'; import { Config } from '../config/config.js';
import * as summarizer from '../utils/summarizer.js'; import * as summarizer from '../utils/summarizer.js';
import { GeminiClient } from '../core/client.js'; import { GeminiClient } from '../core/client.js';
import { ToolExecuteConfirmationDetails } from './tools.js';
import os from 'os'; import os from 'os';
describe('ShellTool', () => {
it('should allow a command if no restrictions are provided', async () => {
const config = {
getCoreTools: () => undefined,
getExcludeTools: () => undefined,
} as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('ls -l');
expect(result.allowed).toBe(true);
});
it('should allow a command if it is in the allowed list', async () => {
const config = {
getCoreTools: () => ['ShellTool(ls -l)'],
getExcludeTools: () => undefined,
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('ls -l');
expect(result.allowed).toBe(true);
});
it('should block a command if it is not in the allowed list', async () => {
const config = {
getCoreTools: () => ['ShellTool(ls -l)'],
getExcludeTools: () => undefined,
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
it('should block a command if it is in the blocked list', async () => {
const config = {
getCoreTools: () => undefined,
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow a command if it is not in the blocked list', async () => {
const config = {
getCoreTools: () => undefined,
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('ls -l');
expect(result.allowed).toBe(true);
});
it('should block a command if it is in both the allowed and blocked lists', async () => {
const config = {
getCoreTools: () => ['ShellTool(rm -rf /)'],
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow any command when ShellTool is in coreTools without specific commands', async () => {
const config = {
getCoreTools: () => ['ShellTool'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('any command');
expect(result.allowed).toBe(true);
});
it('should block any command when ShellTool is in excludeTools without specific commands', async () => {
const config = {
getCoreTools: () => [],
getExcludeTools: () => ['ShellTool'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('any command');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Shell tool is globally disabled in configuration',
);
});
it('should allow a command if it is in the allowed list using the public-facing name', async () => {
const config = {
getCoreTools: () => ['run_shell_command(ls -l)'],
getExcludeTools: () => undefined,
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('ls -l');
expect(result.allowed).toBe(true);
});
it('should block a command if it is in the blocked list using the public-facing name', async () => {
const config = {
getCoreTools: () => undefined,
getExcludeTools: () => ['run_shell_command(rm -rf /)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should block any command when ShellTool is in excludeTools using the public-facing name', async () => {
const config = {
getCoreTools: () => [],
getExcludeTools: () => ['run_shell_command'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('any command');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Shell tool is globally disabled in configuration',
);
});
it('should block any command if coreTools contains an empty ShellTool command list using the public-facing name', async () => {
const config = {
getCoreTools: () => ['run_shell_command()'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('any command');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'any command' is not in the allowed commands list",
);
});
it('should block any command if coreTools contains an empty ShellTool command list', async () => {
const config = {
getCoreTools: () => ['ShellTool()'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('any command');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'any command' is not in the allowed commands list",
);
});
it('should block a command with extra whitespace if it is in the blocked list', async () => {
const config = {
getCoreTools: () => undefined,
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed(' rm -rf / ');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow any command when ShellTool is present with specific commands', async () => {
const config = {
getCoreTools: () => ['ShellTool', 'ShellTool(ls)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('any command');
expect(result.allowed).toBe(true);
});
it('should block a command on the blocklist even with a wildcard allow', async () => {
const config = {
getCoreTools: () => ['ShellTool'],
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow a command that starts with an allowed command prefix', async () => {
const config = {
getCoreTools: () => ['ShellTool(gh issue edit)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed(
'gh issue edit 1 --add-label "kind/feature"',
);
expect(result.allowed).toBe(true);
});
it('should allow a command that starts with an allowed command prefix using the public-facing name', async () => {
const config = {
getCoreTools: () => ['run_shell_command(gh issue edit)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed(
'gh issue edit 1 --add-label "kind/feature"',
);
expect(result.allowed).toBe(true);
});
it('should not allow a command that starts with an allowed command prefix but is chained with another command', async () => {
const config = {
getCoreTools: () => ['run_shell_command(gh issue edit)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('gh issue edit&&rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
it('should not allow a command that is a prefix of an allowed command', async () => {
const config = {
getCoreTools: () => ['run_shell_command(gh issue edit)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('gh issue');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'gh issue' is not in the allowed commands list",
);
});
it('should not allow a command that is a prefix of a blocked command', async () => {
const config = {
getCoreTools: () => [],
getExcludeTools: () => ['run_shell_command(gh issue edit)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('gh issue');
expect(result.allowed).toBe(true);
});
it('should not allow a command that is chained with a pipe', async () => {
const config = {
getCoreTools: () => ['run_shell_command(gh issue list)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('gh issue list | rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
it('should not allow a command that is chained with a semicolon', async () => {
const config = {
getCoreTools: () => ['run_shell_command(gh issue list)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('gh issue list; rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
it('should block a chained command if any part is blocked', async () => {
const config = {
getCoreTools: () => ['run_shell_command(echo "hello")'],
getExcludeTools: () => ['run_shell_command(rm)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('echo "hello" && rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should block a command if its prefix is on the blocklist, even if the command itself is on the allowlist', async () => {
const config = {
getCoreTools: () => ['run_shell_command(git push)'],
getExcludeTools: () => ['run_shell_command(git)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('git push');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'git push' is blocked by configuration",
);
});
it('should be case-sensitive in its matching', async () => {
const config = {
getCoreTools: () => ['run_shell_command(echo)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('ECHO "hello"');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Command \'ECHO "hello"\' is not in the allowed commands list',
);
});
it('should correctly handle commands with extra whitespace around chaining operators', async () => {
const config = {
getCoreTools: () => ['run_shell_command(ls -l)'],
getExcludeTools: () => ['run_shell_command(rm)'],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('ls -l ; rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow a chained command if all parts are allowed', async () => {
const config = {
getCoreTools: () => [
'run_shell_command(echo)',
'run_shell_command(ls -l)',
],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('echo "hello" && ls -l');
expect(result.allowed).toBe(true);
});
it('should allow a command with command substitution using backticks', async () => {
const config = {
getCoreTools: () => ['run_shell_command(echo)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('echo `rm -rf /`');
expect(result.allowed).toBe(true);
});
it('should block a command with command substitution using $()', async () => {
const config = {
getCoreTools: () => ['run_shell_command(echo)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('echo $(rm -rf /)');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Command substitution using $() is not allowed for security reasons',
);
});
it('should allow a command with I/O redirection', async () => {
const config = {
getCoreTools: () => ['run_shell_command(echo)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('echo "hello" > file.txt');
expect(result.allowed).toBe(true);
});
it('should not allow a command that is chained with a double pipe', async () => {
const config = {
getCoreTools: () => ['run_shell_command(gh issue list)'],
getExcludeTools: () => [],
} as unknown as Config;
const shellTool = new ShellTool(config);
const result = shellTool.isCommandAllowed('gh issue list || rm -rf /');
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
});
describe('ShellTool Bug Reproduction', () => { describe('ShellTool Bug Reproduction', () => {
let shellTool: ShellTool; let shellTool: ShellTool;
let config: Config; let config: Config;
@ -427,6 +39,7 @@ describe('ShellTool Bug Reproduction', () => {
const result = await shellTool.execute( const result = await shellTool.execute(
{ command: 'echo hello' }, { command: 'echo hello' },
abortSignal, abortSignal,
() => {},
); );
expect(result.returnDisplay).toBe('hello' + os.EOL); expect(result.returnDisplay).toBe('hello' + os.EOL);
@ -453,6 +66,7 @@ describe('ShellTool Bug Reproduction', () => {
const result = await shellTool.execute( const result = await shellTool.execute(
{ command: 'echo hello' }, { command: 'echo hello' },
abortSignal, abortSignal,
() => {},
); );
expect(result.returnDisplay).toBe('hello' + os.EOL); expect(result.returnDisplay).toBe('hello' + os.EOL);
@ -478,7 +92,7 @@ describe('ShellTool Bug Reproduction', () => {
.mockResolvedValue('summarized output'); .mockResolvedValue('summarized output');
const abortSignal = new AbortController().signal; const abortSignal = new AbortController().signal;
await shellTool.execute({ command: 'echo hello' }, abortSignal); await shellTool.execute({ command: 'echo "hello"' }, abortSignal, () => {});
expect(summarizeSpy).toHaveBeenCalledWith( expect(summarizeSpy).toHaveBeenCalledWith(
expect.any(String), expect.any(String),
@ -506,7 +120,7 @@ describe('ShellTool Bug Reproduction', () => {
.mockResolvedValue('summarized output'); .mockResolvedValue('summarized output');
const abortSignal = new AbortController().signal; const abortSignal = new AbortController().signal;
await shellTool.execute({ command: 'echo hello' }, abortSignal); await shellTool.execute({ command: 'echo "hello"' }, abortSignal, () => {});
expect(summarizeSpy).toHaveBeenCalledWith( expect(summarizeSpy).toHaveBeenCalledWith(
expect.any(String), expect.any(String),
@ -528,10 +142,28 @@ describe('ShellTool Bug Reproduction', () => {
shellTool = new ShellTool(config); shellTool = new ShellTool(config);
const abortSignal = new AbortController().signal; const abortSignal = new AbortController().signal;
const command = const result = await shellTool.execute(
os.platform() === 'win32' ? 'echo %GEMINI_CLI%' : 'echo $GEMINI_CLI'; { command: 'echo "$GEMINI_CLI"' },
const result = await shellTool.execute({ command }, abortSignal); abortSignal,
() => {},
);
expect(result.returnDisplay).toBe('1' + os.EOL); expect(result.returnDisplay).toBe('1' + os.EOL);
}); });
}); });
describe('shouldConfirmExecute', () => {
it('should de-duplicate command roots before asking for confirmation', async () => {
const shellTool = new ShellTool({
getCoreTools: () => ['run_shell_command'],
getExcludeTools: () => [],
} as unknown as Config);
const result = (await shellTool.shouldConfirmExecute(
{
command: 'git status && git log',
},
new AbortController().signal,
)) as ToolExecuteConfirmationDetails;
expect(result.rootCommand).toEqual('git');
});
});

212
packages/core/src/tools/shell.ts
View File

@ -21,6 +21,11 @@ import { Type } from '@google/genai';
import { SchemaValidator } from '../utils/schemaValidator.js'; import { SchemaValidator } from '../utils/schemaValidator.js';
import { getErrorMessage } from '../utils/errors.js'; import { getErrorMessage } from '../utils/errors.js';
import stripAnsi from 'strip-ansi'; import stripAnsi from 'strip-ansi';
import {
getCommandRoots,
isCommandAllowed,
stripShellWrapper,
} from '../utils/shell-utils.js';
export interface ShellToolParams { export interface ShellToolParams {
command: string; command: string;
@ -34,7 +39,7 @@ const OUTPUT_UPDATE_INTERVAL_MS = 1000;
export class ShellTool extends BaseTool<ShellToolParams, ToolResult> { export class ShellTool extends BaseTool<ShellToolParams, ToolResult> {
static Name: string = 'run_shell_command'; static Name: string = 'run_shell_command';
private whitelist: Set<string> = new Set(); private allowlist: Set<string> = new Set();
constructor(private readonly config: Config) { constructor(private readonly config: Config) {
super( super(
@ -42,17 +47,17 @@ export class ShellTool extends BaseTool<ShellToolParams, ToolResult> {
'Shell', 'Shell',
`This tool executes a given shell command as \`bash -c <command>\`. Command can start background processes using \`&\`. Command is executed as a subprocess that leads its own process group. Command process group can be terminated as \`kill -- -PGID\` or signaled as \`kill -s SIGNAL -- -PGID\`. `This tool executes a given shell command as \`bash -c <command>\`. Command can start background processes using \`&\`. Command is executed as a subprocess that leads its own process group. Command process group can be terminated as \`kill -- -PGID\` or signaled as \`kill -s SIGNAL -- -PGID\`.
The following information is returned: The following information is returned:
Command: Executed command. Command: Executed command.
Directory: Directory (relative to project root) where command was executed, or \`(root)\`. Directory: Directory (relative to project root) where command was executed, or \`(root)\`.
Stdout: Output on stdout stream. Can be \`(empty)\` or partial on error and for any unwaited background processes. Stdout: Output on stdout stream. Can be \`(empty)\` or partial on error and for any unwaited background processes.
Stderr: Output on stderr stream. Can be \`(empty)\` or partial on error and for any unwaited background processes. Stderr: Output on stderr stream. Can be \`(empty)\` or partial on error and for any unwaited background processes.
Error: Error or \`(none)\` if no error was reported for the subprocess. Error: Error or \`(none)\` if no error was reported for the subprocess.
Exit Code: Exit code or \`(none)\` if terminated by signal. Exit Code: Exit code or \`(none)\` if terminated by signal.
Signal: Signal number or \`(none)\` if no signal was received. Signal: Signal number or \`(none)\` if no signal was received.
Background PIDs: List of background processes started or \`(none)\`. Background PIDs: List of background processes started or \`(none)\`.
Process Group PGID: Process group started or \`(none)\``, Process Group PGID: Process group started or \`(none)\``,
Icon.Terminal, Icon.Terminal,
{ {
type: Type.OBJECT, type: Type.OBJECT,
@ -93,131 +98,8 @@ Process Group PGID: Process group started or \`(none)\``,
return description; return description;
} }
/**
* Extracts the root command from a given shell command string.
* This is used to identify the base command for permission checks.
*
* @param command The shell command string to parse
* @returns The root command name, or undefined if it cannot be determined
* @example getCommandRoot("ls -la /tmp") returns "ls"
* @example getCommandRoot("git status && npm test") returns "git"
*/
getCommandRoot(command: string): string | undefined {
return command
.trim() // remove leading and trailing whitespace
.replace(/[{}()]/g, '') // remove all grouping operators
.split(/[\s;&|]+/)[0] // split on any whitespace or separator or chaining operators and take first part
?.split(/[/\\]/) // split on any path separators (or return undefined if previous line was undefined)
.pop(); // take last part and return command root (or undefined if previous line was empty)
}
/**
* Determines whether a given shell command is allowed to execute based on
* the tool's configuration including allowlists and blocklists.
*
* @param command The shell command string to validate
* @returns An object with 'allowed' boolean and optional 'reason' string if not allowed
*/
isCommandAllowed(command: string): { allowed: boolean; reason?: string } {
// 0. Disallow command substitution
if (command.includes('$(')) {
return {
allowed: false,
reason:
'Command substitution using $() is not allowed for security reasons',
};
}
const SHELL_TOOL_NAMES = [ShellTool.name, ShellTool.Name];
const normalize = (cmd: string): string => cmd.trim().replace(/\s+/g, ' ');
/**
* Checks if a command string starts with a given prefix, ensuring it's a
* whole word match (i.e., followed by a space or it's an exact match).
* e.g., `isPrefixedBy('npm install', 'npm')` -> true
* e.g., `isPrefixedBy('npm', 'npm')` -> true
* e.g., `isPrefixedBy('npminstall', 'npm')` -> false
*/
const isPrefixedBy = (cmd: string, prefix: string): boolean => {
if (!cmd.startsWith(prefix)) {
return false;
}
return cmd.length === prefix.length || cmd[prefix.length] === ' ';
};
/**
* Extracts and normalizes shell commands from a list of tool strings.
* e.g., 'ShellTool("ls -l")' becomes 'ls -l'
*/
const extractCommands = (tools: string[]): string[] =>
tools.flatMap((tool) => {
for (const toolName of SHELL_TOOL_NAMES) {
if (tool.startsWith(`${toolName}(`) && tool.endsWith(')')) {
return [normalize(tool.slice(toolName.length + 1, -1))];
}
}
return [];
});
const coreTools = this.config.getCoreTools() || [];
const excludeTools = this.config.getExcludeTools() || [];
// 1. Check if the shell tool is globally disabled.
if (SHELL_TOOL_NAMES.some((name) => excludeTools.includes(name))) {
return {
allowed: false,
reason: 'Shell tool is globally disabled in configuration',
};
}
const blockedCommands = new Set(extractCommands(excludeTools));
const allowedCommands = new Set(extractCommands(coreTools));
const hasSpecificAllowedCommands = allowedCommands.size > 0;
const isWildcardAllowed = SHELL_TOOL_NAMES.some((name) =>
coreTools.includes(name),
);
const commandsToValidate = command.split(/&&|\|\||\||;/).map(normalize);
const blockedCommandsArr = [...blockedCommands];
for (const cmd of commandsToValidate) {
// 2. Check if the command is on the blocklist.
const isBlocked = blockedCommandsArr.some((blocked) =>
isPrefixedBy(cmd, blocked),
);
if (isBlocked) {
return {
allowed: false,
reason: `Command '${cmd}' is blocked by configuration`,
};
}
// 3. If in strict allow-list mode, check if the command is permitted.
const isStrictAllowlist =
hasSpecificAllowedCommands && !isWildcardAllowed;
const allowedCommandsArr = [...allowedCommands];
if (isStrictAllowlist) {
const isAllowed = allowedCommandsArr.some((allowed) =>
isPrefixedBy(cmd, allowed),
);
if (!isAllowed) {
return {
allowed: false,
reason: `Command '${cmd}' is not in the allowed commands list`,
};
}
}
}
// 4. If all checks pass, the command is allowed.
return { allowed: true };
}
validateToolParams(params: ShellToolParams): string | null { validateToolParams(params: ShellToolParams): string | null {
const commandCheck = this.isCommandAllowed(params.command); const commandCheck = isCommandAllowed(params.command, this.config);
if (!commandCheck.allowed) { if (!commandCheck.allowed) {
if (!commandCheck.reason) { if (!commandCheck.reason) {
console.error( console.error(
@ -234,7 +116,7 @@ Process Group PGID: Process group started or \`(none)\``,
if (!params.command.trim()) { if (!params.command.trim()) {
return 'Command cannot be empty.'; return 'Command cannot be empty.';
} }
if (!this.getCommandRoot(params.command)) { if (getCommandRoots(params.command).length === 0) {
return 'Could not identify command root to obtain permission from user.'; return 'Could not identify command root to obtain permission from user.';
} }
if (params.directory) { if (params.directory) {
@ -259,18 +141,25 @@ Process Group PGID: Process group started or \`(none)\``,
if (this.validateToolParams(params)) { if (this.validateToolParams(params)) {
return false; // skip confirmation, execute call will fail immediately return false; // skip confirmation, execute call will fail immediately
} }
const rootCommand = this.getCommandRoot(params.command)!; // must be non-empty string post-validation
if (this.whitelist.has(rootCommand)) { const command = stripShellWrapper(params.command);
const rootCommands = [...new Set(getCommandRoots(command))];
const commandsToConfirm = rootCommands.filter(
(command) => !this.allowlist.has(command),
);
if (commandsToConfirm.length === 0) {
return false; // already approved and whitelisted return false; // already approved and whitelisted
} }
const confirmationDetails: ToolExecuteConfirmationDetails = { const confirmationDetails: ToolExecuteConfirmationDetails = {
type: 'exec', type: 'exec',
title: 'Confirm Shell Command', title: 'Confirm Shell Command',
command: params.command, command: params.command,
rootCommand, rootCommand: commandsToConfirm.join(', '),
onConfirm: async (outcome: ToolConfirmationOutcome) => { onConfirm: async (outcome: ToolConfirmationOutcome) => {
if (outcome === ToolConfirmationOutcome.ProceedAlways) { if (outcome === ToolConfirmationOutcome.ProceedAlways) {
this.whitelist.add(rootCommand); commandsToConfirm.forEach((command) => this.allowlist.add(command));
} }
}, },
}; };
@ -279,21 +168,22 @@ Process Group PGID: Process group started or \`(none)\``,
async execute( async execute(
params: ShellToolParams, params: ShellToolParams,
abortSignal: AbortSignal, signal: AbortSignal,
updateOutput?: (chunk: string) => void, updateOutput?: (output: string) => void,
): Promise<ToolResult> { ): Promise<ToolResult> {
const validationError = this.validateToolParams(params); const strippedCommand = stripShellWrapper(params.command);
const validationError = this.validateToolParams({
...params,
command: strippedCommand,
});
if (validationError) { if (validationError) {
return { return {
llmContent: [ llmContent: validationError,
`Command rejected: ${params.command}`, returnDisplay: validationError,
`Reason: ${validationError}`,
].join('\n'),
returnDisplay: `Error: ${validationError}`,
}; };
} }
if (abortSignal.aborted) { if (signal.aborted) {
return { return {
llmContent: 'Command was cancelled by user before it could start.', llmContent: 'Command was cancelled by user before it could start.',
returnDisplay: 'Command cancelled by user.', returnDisplay: 'Command cancelled by user.',
@ -307,18 +197,18 @@ Process Group PGID: Process group started or \`(none)\``,
const tempFilePath = path.join(os.tmpdir(), tempFileName); const tempFilePath = path.join(os.tmpdir(), tempFileName);
// pgrep is not available on Windows, so we can't get background PIDs // pgrep is not available on Windows, so we can't get background PIDs
const command = isWindows const commandToExecute = isWindows
? params.command ? strippedCommand
: (() => { : (() => {
// wrap command to append subprocess pids (via pgrep) to temporary file // wrap command to append subprocess pids (via pgrep) to temporary file
let command = params.command.trim(); let command = strippedCommand.trim();
if (!command.endsWith('&')) command += ';'; if (!command.endsWith('&')) command += ';';
return `{ ${command} }; __code=$?; pgrep -g 0 >${tempFilePath} 2>&1; exit $__code;`; return `{ ${command} }; __code=$?; pgrep -g 0 >${tempFilePath} 2>&1; exit $__code;`;
})(); })();
// spawn command in specified directory (or project root if not specified) // spawn command in specified directory (or project root if not specified)
const shell = isWindows const shell = isWindows
? spawn('cmd.exe', ['/c', command], { ? spawn('cmd.exe', ['/c', commandToExecute], {
stdio: ['ignore', 'pipe', 'pipe'], stdio: ['ignore', 'pipe', 'pipe'],
// detached: true, // ensure subprocess starts its own process group (esp. in Linux) // detached: true, // ensure subprocess starts its own process group (esp. in Linux)
cwd: path.resolve(this.config.getTargetDir(), params.directory || ''), cwd: path.resolve(this.config.getTargetDir(), params.directory || ''),
@ -327,7 +217,7 @@ Process Group PGID: Process group started or \`(none)\``,
GEMINI_CLI: '1', GEMINI_CLI: '1',
}, },
}) })
: spawn('bash', ['-c', command], { : spawn('bash', ['-c', commandToExecute], {
stdio: ['ignore', 'pipe', 'pipe'], stdio: ['ignore', 'pipe', 'pipe'],
detached: true, // ensure subprocess starts its own process group (esp. in Linux) detached: true, // ensure subprocess starts its own process group (esp. in Linux)
cwd: path.resolve(this.config.getTargetDir(), params.directory || ''), cwd: path.resolve(this.config.getTargetDir(), params.directory || ''),
@ -377,7 +267,7 @@ Process Group PGID: Process group started or \`(none)\``,
shell.on('error', (err: Error) => { shell.on('error', (err: Error) => {
error = err; error = err;
// remove wrapper from user's command in error message // remove wrapper from user's command in error message
error.message = error.message.replace(command, params.command); error.message = error.message.replace(commandToExecute, params.command);
}); });
let code: number | null = null; let code: number | null = null;
@ -419,13 +309,13 @@ Process Group PGID: Process group started or \`(none)\``,
} }
} }
}; };
abortSignal.addEventListener('abort', abortHandler); signal.addEventListener('abort', abortHandler);
// wait for the shell to exit // wait for the shell to exit
try { try {
await new Promise((resolve) => shell.on('exit', resolve)); await new Promise((resolve) => shell.on('exit', resolve));
} finally { } finally {
abortSignal.removeEventListener('abort', abortHandler); signal.removeEventListener('abort', abortHandler);
} }
// parse pids (pgrep output) from temporary file and remove it // parse pids (pgrep output) from temporary file and remove it
@ -448,14 +338,14 @@ Process Group PGID: Process group started or \`(none)\``,
} }
fs.unlinkSync(tempFilePath); fs.unlinkSync(tempFilePath);
} else { } else {
if (!abortSignal.aborted) { if (!signal.aborted) {
console.error('missing pgrep output'); console.error('missing pgrep output');
} }
} }
} }
let llmContent = ''; let llmContent = '';
if (abortSignal.aborted) { if (signal.aborted) {
llmContent = 'Command was cancelled by user before it could complete.'; llmContent = 'Command was cancelled by user before it could complete.';
if (output.trim()) { if (output.trim()) {
llmContent += ` Below is the output (on stdout and stderr) before it was cancelled:\n${output}`; llmContent += ` Below is the output (on stdout and stderr) before it was cancelled:\n${output}`;
@ -484,7 +374,7 @@ Process Group PGID: Process group started or \`(none)\``,
returnDisplayMessage = output; returnDisplayMessage = output;
} else { } else {
// Output is empty, let's provide a reason if the command failed or was cancelled // Output is empty, let's provide a reason if the command failed or was cancelled
if (abortSignal.aborted) { if (signal.aborted) {
returnDisplayMessage = 'Command cancelled by user.'; returnDisplayMessage = 'Command cancelled by user.';
} else if (processSignal) { } else if (processSignal) {
returnDisplayMessage = `Command terminated by signal: ${processSignal}`; returnDisplayMessage = `Command terminated by signal: ${processSignal}`;
@ -504,7 +394,7 @@ Process Group PGID: Process group started or \`(none)\``,
const summary = await summarizeToolOutput( const summary = await summarizeToolOutput(
llmContent, llmContent,
this.config.getGeminiClient(), this.config.getGeminiClient(),
abortSignal, signal,
summarizeConfig[this.name].tokenBudget, summarizeConfig[this.name].tokenBudget,
); );
return { return {

583
packages/core/src/utils/shell-utils.test.ts Normal file
View File

@ -0,0 +1,583 @@
/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import { expect, describe, it, beforeEach } from 'vitest';
import {
getCommandRoots,
isCommandAllowed,
stripShellWrapper,
} from './shell-utils.js';
import { Config } from '../config/config.js';
describe('isCommandAllowed', () => {
let config: Config;
beforeEach(() => {
config = {
getCoreTools: () => undefined,
getExcludeTools: () => undefined,
} as unknown as Config;
});
it('should allow a command if no restrictions are provided', async () => {
const result = isCommandAllowed('ls -l', config);
expect(result.allowed).toBe(true);
});
it('should allow a command if it is in the allowed list', async () => {
config = {
getCoreTools: () => ['ShellTool(ls -l)'],
getExcludeTools: () => undefined,
} as unknown as Config;
const result = isCommandAllowed('ls -l', config);
expect(result.allowed).toBe(true);
});
it('should block a command if it is not in the allowed list', async () => {
config = {
getCoreTools: () => ['ShellTool(ls -l)'],
getExcludeTools: () => undefined,
} as unknown as Config;
const result = isCommandAllowed('rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
it('should block a command if it is in the blocked list', async () => {
config = {
getCoreTools: () => undefined,
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const result = isCommandAllowed('rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow a command if it is not in the blocked list', async () => {
config = {
getCoreTools: () => undefined,
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const result = isCommandAllowed('ls -l', config);
expect(result.allowed).toBe(true);
});
it('should block a command if it is in both the allowed and blocked lists', async () => {
config = {
getCoreTools: () => ['ShellTool(rm -rf /)'],
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const result = isCommandAllowed('rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow any command when ShellTool is in coreTools without specific commands', async () => {
config = {
getCoreTools: () => ['ShellTool'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('any command', config);
expect(result.allowed).toBe(true);
});
it('should block any command when ShellTool is in excludeTools without specific commands', async () => {
config = {
getCoreTools: () => [],
getExcludeTools: () => ['ShellTool'],
} as unknown as Config;
const result = isCommandAllowed('any command', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Shell tool is globally disabled in configuration',
);
});
it('should allow a command if it is in the allowed list using the public-facing name', async () => {
config = {
getCoreTools: () => ['run_shell_command(ls -l)'],
getExcludeTools: () => undefined,
} as unknown as Config;
const result = isCommandAllowed('ls -l', config);
expect(result.allowed).toBe(true);
});
it('should block a command if it is in the blocked list using the public-facing name', async () => {
config = {
getCoreTools: () => undefined,
getExcludeTools: () => ['run_shell_command(rm -rf /)'],
} as unknown as Config;
const result = isCommandAllowed('rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should block any command when ShellTool is in excludeTools using the public-facing name', async () => {
config = {
getCoreTools: () => [],
getExcludeTools: () => ['run_shell_command'],
} as unknown as Config;
const result = isCommandAllowed('any command', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Shell tool is globally disabled in configuration',
);
});
it('should block any command if coreTools contains an empty ShellTool command list using the public-facing name', async () => {
config = {
getCoreTools: () => ['run_shell_command()'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('any command', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'any command' is not in the allowed commands list",
);
});
it('should block any command if coreTools contains an empty ShellTool command list', async () => {
config = {
getCoreTools: () => ['ShellTool()'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('any command', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'any command' is not in the allowed commands list",
);
});
it('should block a command with extra whitespace if it is in the blocked list', async () => {
config = {
getCoreTools: () => undefined,
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const result = isCommandAllowed(' rm -rf / ', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow any command when ShellTool is in present with specific commands', async () => {
config = {
getCoreTools: () => ['ShellTool', 'ShellTool(ls)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('any command', config);
expect(result.allowed).toBe(true);
});
it('should block a command on the blocklist even with a wildcard allow', async () => {
config = {
getCoreTools: () => ['ShellTool'],
getExcludeTools: () => ['ShellTool(rm -rf /)'],
} as unknown as Config;
const result = isCommandAllowed('rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow a command that starts with an allowed command prefix', async () => {
config = {
getCoreTools: () => ['ShellTool(gh issue edit)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed(
'gh issue edit 1 --add-label "kind/feature"',
config,
);
expect(result.allowed).toBe(true);
});
it('should allow a command that starts with an allowed command prefix using the public-facing name', async () => {
config = {
getCoreTools: () => ['run_shell_command(gh issue edit)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed(
'gh issue edit 1 --add-label "kind/feature"',
config,
);
expect(result.allowed).toBe(true);
});
it('should not allow a command that starts with an allowed command prefix but is chained with another command', async () => {
config = {
getCoreTools: () => ['run_shell_command(gh issue edit)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('gh issue edit&&rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
it('should not allow a command that is a prefix of an allowed command', async () => {
config = {
getCoreTools: () => ['run_shell_command(gh issue edit)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('gh issue', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'gh issue' is not in the allowed commands list",
);
});
it('should not allow a command that is a prefix of a blocked command', async () => {
config = {
getCoreTools: () => [],
getExcludeTools: () => ['run_shell_command(gh issue edit)'],
} as unknown as Config;
const result = isCommandAllowed('gh issue', config);
expect(result.allowed).toBe(true);
});
it('should not allow a command that is chained with a pipe', async () => {
config = {
getCoreTools: () => ['run_shell_command(gh issue list)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('gh issue list | rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
it('should not allow a command that is chained with a semicolon', async () => {
config = {
getCoreTools: () => ['run_shell_command(gh issue list)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('gh issue list; rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
it('should block a chained command if any part is blocked', async () => {
config = {
getCoreTools: () => ['run_shell_command(echo "hello")'],
getExcludeTools: () => ['run_shell_command(rm)'],
} as unknown as Config;
const result = isCommandAllowed('echo "hello" && rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should block a command if its prefix is on the blocklist, even if the command itself is on the allowlist', async () => {
config = {
getCoreTools: () => ['run_shell_command(git push)'],
getExcludeTools: () => ['run_shell_command(git)'],
} as unknown as Config;
const result = isCommandAllowed('git push', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'git push' is blocked by configuration",
);
});
it('should be case-sensitive in its matching', async () => {
config = {
getCoreTools: () => ['run_shell_command(echo)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('ECHO "hello"', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Command \'ECHO "hello"\' is not in the allowed commands list',
);
});
it('should correctly handle commands with extra whitespace around chaining operators', async () => {
config = {
getCoreTools: () => ['run_shell_command(ls -l)'],
getExcludeTools: () => ['run_shell_command(rm)'],
} as unknown as Config;
const result = isCommandAllowed('ls -l ; rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is blocked by configuration",
);
});
it('should allow a chained command if all parts are allowed', async () => {
config = {
getCoreTools: () => [
'run_shell_command(echo)',
'run_shell_command(ls -l)',
],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('echo "hello" && ls -l', config);
expect(result.allowed).toBe(true);
});
it('should block a command with command substitution using backticks', async () => {
config = {
getCoreTools: () => ['run_shell_command(echo)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('echo `rm -rf /`', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Command substitution using $(), <(), or >() is not allowed for security reasons',
);
});
it('should block a command with command substitution using $()', async () => {
config = {
getCoreTools: () => ['run_shell_command(echo)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('echo $(rm -rf /)', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Command substitution using $(), <(), or >() is not allowed for security reasons',
);
});
it('should block a command with process substitution using <()', async () => {
config = {
getCoreTools: () => ['run_shell_command(diff)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('diff <(ls) <(ls -a)', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
'Command substitution using $(), <(), or >() is not allowed for security reasons',
);
});
it('should allow a command with I/O redirection', async () => {
config = {
getCoreTools: () => ['run_shell_command(echo)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('echo "hello" > file.txt', config);
expect(result.allowed).toBe(true);
});
it('should not allow a command that is chained with a double pipe', async () => {
config = {
getCoreTools: () => ['run_shell_command(gh issue list)'],
getExcludeTools: () => [],
} as unknown as Config;
const result = isCommandAllowed('gh issue list || rm -rf /', config);
expect(result.allowed).toBe(false);
expect(result.reason).toBe(
"Command 'rm -rf /' is not in the allowed commands list",
);
});
});
describe('getCommandRoots', () => {
it('should return a single command', () => {
const result = getCommandRoots('ls -l');
expect(result).toEqual(['ls']);
});
it('should return multiple commands', () => {
const result = getCommandRoots('ls -l | grep "test"');
expect(result).toEqual(['ls', 'grep']);
});
it('should handle multiple commands with &&', () => {
const result = getCommandRoots('npm run build && npm test');
expect(result).toEqual(['npm', 'npm']);
});
it('should handle multiple commands with ;', () => {
const result = getCommandRoots('echo "hello"; echo "world"');
expect(result).toEqual(['echo', 'echo']);
});
it('should handle a mix of operators', () => {
const result = getCommandRoots(
'cat package.json | grep "version" && echo "done"',
);
expect(result).toEqual(['cat', 'grep', 'echo']);
});
it('should handle commands with paths', () => {
const result = getCommandRoots('/usr/local/bin/node script.js');
expect(result).toEqual(['node']);
});
it('should return an empty array for an empty string', () => {
const result = getCommandRoots('');
expect(result).toEqual([]);
});
});
describe('stripShellWrapper', () => {
it('should strip sh -c from the beginning of the command', () => {
const result = stripShellWrapper('sh -c "ls -l"');
expect(result).toEqual('ls -l');
});
it('should strip bash -c from the beginning of the command', () => {
const result = stripShellWrapper('bash -c "ls -l"');
expect(result).toEqual('ls -l');
});
it('should strip zsh -c from the beginning of the command', () => {
const result = stripShellWrapper('zsh -c "ls -l"');
expect(result).toEqual('ls -l');
});
it('should not strip anything if the command does not start with a shell wrapper', () => {
const result = stripShellWrapper('ls -l');
expect(result).toEqual('ls -l');
});
it('should handle extra whitespace', () => {
const result = stripShellWrapper(' sh -c "ls -l" ');
expect(result).toEqual('ls -l');
});
it('should handle commands without quotes', () => {
const result = stripShellWrapper('sh -c ls -l');
expect(result).toEqual('ls -l');
});
it('should strip cmd.exe /c from the beginning of the command', () => {
const result = stripShellWrapper('cmd.exe /c "dir"');
expect(result).toEqual('dir');
});
});
describe('getCommandRoots', () => {
it('should handle multiple commands with &', () => {
const result = getCommandRoots('echo "hello" & echo "world"');
expect(result).toEqual(['echo', 'echo']);
});
});
describe('command substitution', () => {
let config: Config;
beforeEach(() => {
config = {
getCoreTools: () => ['run_shell_command(echo)', 'run_shell_command(gh)'],
getExcludeTools: () => [],
} as unknown as Config;
});
it('should block unquoted command substitution `$(...)`', () => {
const result = isCommandAllowed('echo $(pwd)', config);
expect(result.allowed).toBe(false);
});
it('should block unquoted command substitution `<(...)`', () => {
const result = isCommandAllowed('echo <(pwd)', config);
expect(result.allowed).toBe(false);
});
it('should allow command substitution in single quotes', () => {
const result = isCommandAllowed("echo '$(pwd)'", config);
expect(result.allowed).toBe(true);
});
it('should allow backticks in single quotes', () => {
const result = isCommandAllowed("echo '`rm -rf /`'", config);
expect(result.allowed).toBe(true);
});
it('should block command substitution in double quotes', () => {
const result = isCommandAllowed('echo "$(pwd)"', config);
expect(result.allowed).toBe(false);
});
it('should allow escaped command substitution', () => {
const result = isCommandAllowed('echo \\$(pwd)', config);
expect(result.allowed).toBe(true);
});
it('should allow complex commands with quoted substitution-like patterns', () => {
const command =
"gh pr comment 4795 --body 'This is a test comment with $(pwd) style text'";
const result = isCommandAllowed(command, config);
expect(result.allowed).toBe(true);
});
it('should block complex commands with unquoted substitution-like patterns', () => {
const command =
'gh pr comment 4795 --body "This is a test comment with $(pwd) style text"';
const result = isCommandAllowed(command, config);
expect(result.allowed).toBe(false);
});
it('should allow a command with markdown content using proper quoting', () => {
// Simple test with safe content in single quotes
const result = isCommandAllowed(
"gh pr comment 4795 --body 'This is safe markdown content'",
config,
);
expect(result.allowed).toBe(true);
});
});
describe('getCommandRoots with quote handling', () => {
it('should correctly parse a simple command', () => {
const result = getCommandRoots('git status');
expect(result).toEqual(['git']);
});
it('should correctly parse a command with a quoted argument', () => {
const result = getCommandRoots('git commit -m "feat: new feature"');
expect(result).toEqual(['git']);
});
it('should correctly parse a command with single quotes', () => {
const result = getCommandRoots("echo 'hello world'");
expect(result).toEqual(['echo']);
});
it('should correctly parse a chained command with quotes', () => {
const result = getCommandRoots('echo "hello" && git status');
expect(result).toEqual(['echo', 'git']);
});
it('should correctly parse a complex chained command', () => {
const result = getCommandRoots(
'git commit -m "feat: new feature" && echo "done"',
);
expect(result).toEqual(['git', 'echo']);
});
it('should handle escaped quotes', () => {
const result = getCommandRoots('echo "this is a "quote""');
expect(result).toEqual(['echo']);
});
it('should handle commands with no spaces', () => {
const result = getCommandRoots('command');
expect(result).toEqual(['command']);
});
it('should handle multiple separators', () => {
const result = getCommandRoots('a;b|c&&d||e&f');
expect(result).toEqual(['a', 'b', 'c', 'd', 'e', 'f']);
});
});

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/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import { Config } from '../config/config.js';
/**
* Splits a shell command into a list of individual commands, respecting quotes.
* This is used to separate chained commands (e.g., using &&, ||, ;).
* @param command The shell command string to parse
* @returns An array of individual command strings
*/
export function splitCommands(command: string): string[] {
const commands: string[] = [];
let currentCommand = '';
let inSingleQuotes = false;
let inDoubleQuotes = false;
let i = 0;
while (i < command.length) {
const char = command[i];
const nextChar = command[i + 1];
if (char === '\\' && i < command.length - 1) {
currentCommand += char + command[i + 1];
i += 2;
continue;
}
if (char === "'" && !inDoubleQuotes) {
inSingleQuotes = !inSingleQuotes;
} else if (char === '"' && !inSingleQuotes) {
inDoubleQuotes = !inDoubleQuotes;
}
if (!inSingleQuotes && !inDoubleQuotes) {
if (
(char === '&' && nextChar === '&') ||
(char === '|' && nextChar === '|')
) {
commands.push(currentCommand.trim());
currentCommand = '';
i++; // Skip the next character
} else if (char === ';' || char === '&' || char === '|') {
commands.push(currentCommand.trim());
currentCommand = '';
} else {
currentCommand += char;
}
} else {
currentCommand += char;
}
i++;
}
if (currentCommand.trim()) {
commands.push(currentCommand.trim());
}
return commands.filter(Boolean); // Filter out any empty strings
}
/**
* Extracts the root command from a given shell command string.
* This is used to identify the base command for permission checks.
* @param command The shell command string to parse
* @returns The root command name, or undefined if it cannot be determined
* @example getCommandRoot("ls -la /tmp") returns "ls"
* @example getCommandRoot("git status && npm test") returns "git"
*/
export function getCommandRoot(command: string): string | undefined {
const trimmedCommand = command.trim();
if (!trimmedCommand) {
return undefined;
}
// This regex is designed to find the first "word" of a command,
// while respecting quotes. It looks for a sequence of non-whitespace
// characters that are not inside quotes.
const match = trimmedCommand.match(/^"([^"]+)"|^'([^']+)'|^(\S+)/);
if (match) {
// The first element in the match array is the full match.
// The subsequent elements are the capture groups.
// We prefer a captured group because it will be unquoted.
const commandRoot = match[1] || match[2] || match[3];
if (commandRoot) {
// If the command is a path, return the last component.
return commandRoot.split(/[\\/]/).pop();
}
}
return undefined;
}
export function getCommandRoots(command: string): string[] {
if (!command) {
return [];
}
return splitCommands(command)
.map((c) => getCommandRoot(c))
.filter((c): c is string => !!c);
}
export function stripShellWrapper(command: string): string {
const pattern = /^\s*(?:sh|bash|zsh|cmd.exe)\s+(?:\/c|-c)\s+/;
const match = command.match(pattern);
if (match) {
let newCommand = command.substring(match[0].length).trim();
if (
(newCommand.startsWith('"') && newCommand.endsWith('"')) ||
(newCommand.startsWith("'") && newCommand.endsWith("'"))
) {
newCommand = newCommand.substring(1, newCommand.length - 1);
}
return newCommand;
}
return command.trim();
}
/**
* Detects command substitution patterns in a shell command, following bash quoting rules:
* - Single quotes ('): Everything literal, no substitution possible
* - Double quotes ("): Command substitution with $() and backticks unless escaped with \
* - No quotes: Command substitution with $(), <(), and backticks
* @param command The shell command string to check
* @returns true if command substitution would be executed by bash
*/
export function detectCommandSubstitution(command: string): boolean {
let inSingleQuotes = false;
let inDoubleQuotes = false;
let inBackticks = false;
let i = 0;
while (i < command.length) {
const char = command[i];
const nextChar = command[i + 1];
// Handle escaping - only works outside single quotes
if (char === '\\' && !inSingleQuotes) {
i += 2; // Skip the escaped character
continue;
}
// Handle quote state changes
if (char === "'" && !inDoubleQuotes && !inBackticks) {
inSingleQuotes = !inSingleQuotes;
} else if (char === '"' && !inSingleQuotes && !inBackticks) {
inDoubleQuotes = !inDoubleQuotes;
} else if (char === '`' && !inSingleQuotes) {
// Backticks work outside single quotes (including in double quotes)
inBackticks = !inBackticks;
}
// Check for command substitution patterns that would be executed
if (!inSingleQuotes) {
// $(...) command substitution - works in double quotes and unquoted
if (char === '$' && nextChar === '(') {
return true;
}
// <(...) process substitution - works unquoted only (not in double quotes)
if (char === '<' && nextChar === '(' && !inDoubleQuotes && !inBackticks) {
return true;
}
// Backtick command substitution - check for opening backtick
// (We track the state above, so this catches the start of backtick substitution)
if (char === '`' && !inBackticks) {
return true;
}
}
i++;
}
return false;
}
/**
* Determines whether a given shell command is allowed to execute based on
* the tool's configuration including allowlists and blocklists.
* @param command The shell command string to validate
* @param config The application configuration
* @returns An object with 'allowed' boolean and optional 'reason' string if not allowed
*/
export function isCommandAllowed(
command: string,
config: Config,
): { allowed: boolean; reason?: string } {
// 0. Disallow command substitution
// Parse the command to check for unquoted/unescaped command substitution
const hasCommandSubstitution = detectCommandSubstitution(command);
if (hasCommandSubstitution) {
return {
allowed: false,
reason:
'Command substitution using $(), <(), or >() is not allowed for security reasons',
};
}
const SHELL_TOOL_NAMES = ['run_shell_command', 'ShellTool'];
const normalize = (cmd: string): string => cmd.trim().replace(/\s+/g, ' ');
/**
* Checks if a command string starts with a given prefix, ensuring it's a
* whole word match (i.e., followed by a space or it's an exact match).
* e.g., `isPrefixedBy('npm install', 'npm')` -> true
* e.g., `isPrefixedBy('npm', 'npm')` -> true
* e.g., `isPrefixedBy('npminstall', 'npm')` -> false
*/
const isPrefixedBy = (cmd: string, prefix: string): boolean => {
if (!cmd.startsWith(prefix)) {
return false;
}
return cmd.length === prefix.length || cmd[prefix.length] === ' ';
};
/**
* Extracts and normalizes shell commands from a list of tool strings.
* e.g., 'ShellTool("ls -l")' becomes 'ls -l'
*/
const extractCommands = (tools: string[]): string[] =>
tools.flatMap((tool) => {
for (const toolName of SHELL_TOOL_NAMES) {
if (tool.startsWith(`${toolName}(`) && tool.endsWith(')')) {
return [normalize(tool.slice(toolName.length + 1, -1))];
}
}
return [];
});
const coreTools = config.getCoreTools() || [];
const excludeTools = config.getExcludeTools() || [];
// 1. Check if the shell tool is globally disabled.
if (SHELL_TOOL_NAMES.some((name) => excludeTools.includes(name))) {
return {
allowed: false,
reason: 'Shell tool is globally disabled in configuration',
};
}
const blockedCommands = new Set(extractCommands(excludeTools));
const allowedCommands = new Set(extractCommands(coreTools));
const hasSpecificAllowedCommands = allowedCommands.size > 0;
const isWildcardAllowed = SHELL_TOOL_NAMES.some((name) =>
coreTools.includes(name),
);
const commandsToValidate = splitCommands(command).map(normalize);
const blockedCommandsArr = [...blockedCommands];
for (const cmd of commandsToValidate) {
// 2. Check if the command is on the blocklist.
const isBlocked = blockedCommandsArr.some((blocked) =>
isPrefixedBy(cmd, blocked),
);
if (isBlocked) {
return {
allowed: false,
reason: `Command '${cmd}' is blocked by configuration`,
};
}
// 3. If in strict allow-list mode, check if the command is permitted.
const isStrictAllowlist = hasSpecificAllowedCommands && !isWildcardAllowed;
const allowedCommandsArr = [...allowedCommands];
if (isStrictAllowlist) {
const isAllowed = allowedCommandsArr.some((allowed) =>
isPrefixedBy(cmd, allowed),
);
if (!isAllowed) {
return {
allowed: false,
reason: `Command '${cmd}' is not in the allowed commands list`,
};
}
}
}
// 4. If all checks pass, the command is allowed.
return { allowed: true };
}