mirror of
https://github.com/google-gemini/gemini-cli.git
synced 2026-04-06 11:21:15 -07:00
572 lines
18 KiB
TypeScript
572 lines
18 KiB
TypeScript
/**
|
|
* @license
|
|
* Copyright 2025 Google LLC
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
import { type FunctionCall } from '@google/genai';
|
|
import {
|
|
PolicyDecision,
|
|
type PolicyEngineConfig,
|
|
type PolicyRule,
|
|
type SafetyCheckerRule,
|
|
type HookCheckerRule,
|
|
type HookExecutionContext,
|
|
getHookSource,
|
|
ApprovalMode,
|
|
} from './types.js';
|
|
import { stableStringify } from './stable-stringify.js';
|
|
import { debugLogger } from '../utils/debugLogger.js';
|
|
import type { CheckerRunner } from '../safety/checker-runner.js';
|
|
import { SafetyCheckDecision } from '../safety/protocol.js';
|
|
import type { HookExecutionRequest } from '../confirmation-bus/types.js';
|
|
import {
|
|
SHELL_TOOL_NAMES,
|
|
initializeShellParsers,
|
|
splitCommands,
|
|
hasRedirection,
|
|
} from '../utils/shell-utils.js';
|
|
|
|
function ruleMatches(
|
|
rule: PolicyRule | SafetyCheckerRule,
|
|
toolCall: FunctionCall,
|
|
stringifiedArgs: string | undefined,
|
|
serverName: string | undefined,
|
|
currentApprovalMode: ApprovalMode,
|
|
): boolean {
|
|
// Check if rule applies to current approval mode
|
|
if (rule.modes && rule.modes.length > 0) {
|
|
if (!rule.modes.includes(currentApprovalMode)) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Check tool name if specified
|
|
if (rule.toolName) {
|
|
// Support wildcard patterns: "serverName__*" matches "serverName__anyTool"
|
|
if (rule.toolName.endsWith('__*')) {
|
|
const prefix = rule.toolName.slice(0, -3); // Remove "__*"
|
|
if (serverName !== undefined) {
|
|
// Robust check: if serverName is provided, it MUST match the prefix exactly.
|
|
// This prevents "malicious-server" from spoofing "trusted-server" by naming itself "trusted-server__malicious".
|
|
if (serverName !== prefix) {
|
|
return false;
|
|
}
|
|
}
|
|
// Always verify the prefix, even if serverName matched
|
|
if (!toolCall.name || !toolCall.name.startsWith(prefix + '__')) {
|
|
return false;
|
|
}
|
|
} else if (toolCall.name !== rule.toolName) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Check args pattern if specified
|
|
if (rule.argsPattern) {
|
|
// If rule has an args pattern but tool has no args, no match
|
|
if (!toolCall.args) {
|
|
return false;
|
|
}
|
|
// Use stable JSON stringification with sorted keys to ensure consistent matching
|
|
if (
|
|
stringifiedArgs === undefined ||
|
|
!rule.argsPattern.test(stringifiedArgs)
|
|
) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Check if a hook checker rule matches a hook execution context.
|
|
*/
|
|
function hookCheckerMatches(
|
|
rule: HookCheckerRule,
|
|
context: HookExecutionContext,
|
|
): boolean {
|
|
// Check event name if specified
|
|
if (rule.eventName && rule.eventName !== context.eventName) {
|
|
return false;
|
|
}
|
|
|
|
// Check hook source if specified
|
|
if (rule.hookSource && rule.hookSource !== context.hookSource) {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
export class PolicyEngine {
|
|
private rules: PolicyRule[];
|
|
private checkers: SafetyCheckerRule[];
|
|
private hookCheckers: HookCheckerRule[];
|
|
private readonly defaultDecision: PolicyDecision;
|
|
private readonly nonInteractive: boolean;
|
|
private readonly checkerRunner?: CheckerRunner;
|
|
private readonly allowHooks: boolean;
|
|
private approvalMode: ApprovalMode;
|
|
|
|
constructor(config: PolicyEngineConfig = {}, checkerRunner?: CheckerRunner) {
|
|
this.rules = (config.rules ?? []).sort(
|
|
(a, b) => (b.priority ?? 0) - (a.priority ?? 0),
|
|
);
|
|
this.checkers = (config.checkers ?? []).sort(
|
|
(a, b) => (b.priority ?? 0) - (a.priority ?? 0),
|
|
);
|
|
this.hookCheckers = (config.hookCheckers ?? []).sort(
|
|
(a, b) => (b.priority ?? 0) - (a.priority ?? 0),
|
|
);
|
|
this.defaultDecision = config.defaultDecision ?? PolicyDecision.ASK_USER;
|
|
this.nonInteractive = config.nonInteractive ?? false;
|
|
this.checkerRunner = checkerRunner;
|
|
this.allowHooks = config.allowHooks ?? true;
|
|
this.approvalMode = config.approvalMode ?? ApprovalMode.DEFAULT;
|
|
}
|
|
|
|
/**
|
|
* Update the current approval mode.
|
|
*/
|
|
setApprovalMode(mode: ApprovalMode): void {
|
|
this.approvalMode = mode;
|
|
}
|
|
|
|
/**
|
|
* Get the current approval mode.
|
|
*/
|
|
getApprovalMode(): ApprovalMode {
|
|
return this.approvalMode;
|
|
}
|
|
|
|
/**
|
|
* Check if a shell command is allowed.
|
|
*/
|
|
private async checkShellCommand(
|
|
toolName: string,
|
|
command: string | undefined,
|
|
ruleDecision: PolicyDecision,
|
|
serverName: string | undefined,
|
|
dir_path: string | undefined,
|
|
allowRedirection?: boolean,
|
|
rule?: PolicyRule,
|
|
): Promise<{ decision: PolicyDecision; rule?: PolicyRule }> {
|
|
if (!command) {
|
|
return {
|
|
decision: this.applyNonInteractiveMode(ruleDecision),
|
|
rule,
|
|
};
|
|
}
|
|
|
|
await initializeShellParsers();
|
|
const subCommands = splitCommands(command);
|
|
|
|
if (subCommands.length === 0) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] Command parsing failed for: ${command}. Falling back to ASK_USER.`,
|
|
);
|
|
// Parsing logic failed, we can't trust it. Force ASK_USER (or DENY).
|
|
// We don't blame a specific rule here, unless the input rule was stricter.
|
|
return {
|
|
decision: this.applyNonInteractiveMode(PolicyDecision.ASK_USER),
|
|
rule: undefined,
|
|
};
|
|
}
|
|
|
|
// If there are multiple parts, or if we just want to validate the single part against DENY rules
|
|
if (subCommands.length > 0) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] Validating shell command: ${subCommands.length} parts`,
|
|
);
|
|
|
|
if (ruleDecision === PolicyDecision.DENY) {
|
|
return { decision: PolicyDecision.DENY, rule };
|
|
}
|
|
|
|
// Start optimistically. If all parts are ALLOW, the whole is ALLOW.
|
|
// We will downgrade if any part is ASK_USER or DENY.
|
|
let aggregateDecision = PolicyDecision.ALLOW;
|
|
let responsibleRule: PolicyRule | undefined;
|
|
|
|
for (const rawSubCmd of subCommands) {
|
|
const subCmd = rawSubCmd.trim();
|
|
// Prevent infinite recursion for the root command
|
|
if (subCmd === command) {
|
|
if (!allowRedirection && hasRedirection(subCmd)) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] Downgrading ALLOW to ASK_USER for redirected command: ${subCmd}`,
|
|
);
|
|
// Redirection always downgrades ALLOW to ASK_USER
|
|
if (aggregateDecision === PolicyDecision.ALLOW) {
|
|
aggregateDecision = PolicyDecision.ASK_USER;
|
|
responsibleRule = undefined; // Inherent policy
|
|
}
|
|
} else {
|
|
// Atomic command matching the rule.
|
|
if (
|
|
ruleDecision === PolicyDecision.ASK_USER &&
|
|
aggregateDecision === PolicyDecision.ALLOW
|
|
) {
|
|
aggregateDecision = PolicyDecision.ASK_USER;
|
|
responsibleRule = rule;
|
|
}
|
|
}
|
|
continue;
|
|
}
|
|
|
|
const subResult = await this.check(
|
|
{ name: toolName, args: { command: subCmd, dir_path } },
|
|
serverName,
|
|
);
|
|
|
|
// subResult.decision is already filtered through applyNonInteractiveMode by this.check()
|
|
const subDecision = subResult.decision;
|
|
|
|
// If any part is DENIED, the whole command is DENIED
|
|
if (subDecision === PolicyDecision.DENY) {
|
|
return {
|
|
decision: PolicyDecision.DENY,
|
|
rule: subResult.rule,
|
|
};
|
|
}
|
|
|
|
// If any part requires ASK_USER, the whole command requires ASK_USER
|
|
if (subDecision === PolicyDecision.ASK_USER) {
|
|
aggregateDecision = PolicyDecision.ASK_USER;
|
|
if (!responsibleRule) {
|
|
responsibleRule = subResult.rule;
|
|
}
|
|
}
|
|
|
|
// Check for redirection in allowed sub-commands
|
|
if (
|
|
subDecision === PolicyDecision.ALLOW &&
|
|
!allowRedirection &&
|
|
hasRedirection(subCmd)
|
|
) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] Downgrading ALLOW to ASK_USER for redirected command: ${subCmd}`,
|
|
);
|
|
if (aggregateDecision === PolicyDecision.ALLOW) {
|
|
aggregateDecision = PolicyDecision.ASK_USER;
|
|
responsibleRule = undefined;
|
|
}
|
|
}
|
|
}
|
|
return {
|
|
decision: this.applyNonInteractiveMode(aggregateDecision),
|
|
// If we stayed at ALLOW, we return the original rule (if any).
|
|
// If we downgraded, we return the responsible rule (or undefined if implicit).
|
|
rule: aggregateDecision === ruleDecision ? rule : responsibleRule,
|
|
};
|
|
}
|
|
|
|
return {
|
|
decision: this.applyNonInteractiveMode(ruleDecision),
|
|
rule,
|
|
};
|
|
}
|
|
|
|
/**
|
|
* Check if a tool call is allowed based on the configured policies.
|
|
* Returns the decision and the matching rule (if any).
|
|
*/
|
|
async check(
|
|
toolCall: FunctionCall,
|
|
serverName: string | undefined,
|
|
): Promise<{
|
|
decision: PolicyDecision;
|
|
rule?: PolicyRule;
|
|
}> {
|
|
let stringifiedArgs: string | undefined;
|
|
// Compute stringified args once before the loop
|
|
if (
|
|
toolCall.args &&
|
|
(this.rules.some((rule) => rule.argsPattern) ||
|
|
this.checkers.some((checker) => checker.argsPattern))
|
|
) {
|
|
stringifiedArgs = stableStringify(toolCall.args);
|
|
}
|
|
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] toolCall.name: ${toolCall.name}, stringifiedArgs: ${stringifiedArgs}`,
|
|
);
|
|
|
|
// Check for shell commands upfront to handle splitting
|
|
let isShellCommand = false;
|
|
let command: string | undefined;
|
|
let shellDirPath: string | undefined;
|
|
|
|
if (toolCall.name && SHELL_TOOL_NAMES.includes(toolCall.name)) {
|
|
isShellCommand = true;
|
|
const args = toolCall.args as { command?: string; dir_path?: string };
|
|
command = args?.command;
|
|
shellDirPath = args?.dir_path;
|
|
}
|
|
|
|
// Find the first matching rule (already sorted by priority)
|
|
let matchedRule: PolicyRule | undefined;
|
|
let decision: PolicyDecision | undefined;
|
|
|
|
// For tools with a server name, we want to try matching both the
|
|
// original name and the fully qualified name (server__tool).
|
|
const toolCallsToTry: FunctionCall[] = [toolCall];
|
|
if (serverName && toolCall.name && !toolCall.name.includes('__')) {
|
|
toolCallsToTry.push({
|
|
...toolCall,
|
|
name: `${serverName}__${toolCall.name}`,
|
|
});
|
|
}
|
|
|
|
for (const rule of this.rules) {
|
|
const match = toolCallsToTry.some((tc) =>
|
|
ruleMatches(rule, tc, stringifiedArgs, serverName, this.approvalMode),
|
|
);
|
|
|
|
if (match) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] MATCHED rule: toolName=${rule.toolName}, decision=${rule.decision}, priority=${rule.priority}, argsPattern=${rule.argsPattern?.source || 'none'}`,
|
|
);
|
|
|
|
if (isShellCommand) {
|
|
const shellResult = await this.checkShellCommand(
|
|
toolCall.name!,
|
|
command,
|
|
rule.decision,
|
|
serverName,
|
|
shellDirPath,
|
|
rule.allowRedirection,
|
|
rule,
|
|
);
|
|
decision = shellResult.decision;
|
|
if (shellResult.rule) {
|
|
matchedRule = shellResult.rule;
|
|
break;
|
|
}
|
|
// If no rule returned (e.g. downgraded to default ASK_USER due to redirection),
|
|
// we might still want to blame the matched rule?
|
|
// No, test says we should return undefined rule if implicit.
|
|
matchedRule = shellResult.rule;
|
|
break;
|
|
} else {
|
|
decision = this.applyNonInteractiveMode(rule.decision);
|
|
matchedRule = rule;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!decision) {
|
|
// No matching rule found, use default decision
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] NO MATCH - using default decision: ${this.defaultDecision}`,
|
|
);
|
|
decision = this.applyNonInteractiveMode(this.defaultDecision);
|
|
|
|
// If it's a shell command and we fell back to default, we MUST still verify subcommands!
|
|
// This is critical for security: "git commit && git push" where "git push" is DENY but "git commit" has no rule.
|
|
if (isShellCommand && decision !== PolicyDecision.DENY) {
|
|
const shellResult = await this.checkShellCommand(
|
|
toolCall.name!,
|
|
command,
|
|
decision, // default decision
|
|
serverName,
|
|
shellDirPath,
|
|
false, // no rule, so no allowRedirection
|
|
undefined, // no rule
|
|
);
|
|
decision = shellResult.decision;
|
|
matchedRule = shellResult.rule;
|
|
}
|
|
}
|
|
|
|
// If decision is not DENY, run safety checkers
|
|
if (decision !== PolicyDecision.DENY && this.checkerRunner) {
|
|
for (const checkerRule of this.checkers) {
|
|
if (
|
|
ruleMatches(
|
|
checkerRule,
|
|
toolCall,
|
|
stringifiedArgs,
|
|
serverName,
|
|
this.approvalMode,
|
|
)
|
|
) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] Running safety checker: ${checkerRule.checker.name}`,
|
|
);
|
|
try {
|
|
const result = await this.checkerRunner.runChecker(
|
|
toolCall,
|
|
checkerRule.checker,
|
|
);
|
|
|
|
if (result.decision === SafetyCheckDecision.DENY) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] Safety checker denied: ${result.reason}`,
|
|
);
|
|
return {
|
|
decision: PolicyDecision.DENY,
|
|
rule: matchedRule,
|
|
};
|
|
} else if (result.decision === SafetyCheckDecision.ASK_USER) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] Safety checker requested ASK_USER: ${result.reason}`,
|
|
);
|
|
decision = PolicyDecision.ASK_USER;
|
|
}
|
|
} catch (error) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.check] Safety checker failed: ${error}`,
|
|
);
|
|
return {
|
|
decision: PolicyDecision.DENY,
|
|
rule: matchedRule,
|
|
};
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return {
|
|
decision: this.applyNonInteractiveMode(decision),
|
|
rule: matchedRule,
|
|
};
|
|
}
|
|
|
|
/**
|
|
* Add a new rule to the policy engine.
|
|
*/
|
|
addRule(rule: PolicyRule): void {
|
|
this.rules.push(rule);
|
|
// Re-sort rules by priority
|
|
this.rules.sort((a, b) => (b.priority ?? 0) - (a.priority ?? 0));
|
|
}
|
|
|
|
addChecker(checker: SafetyCheckerRule): void {
|
|
this.checkers.push(checker);
|
|
this.checkers.sort((a, b) => (b.priority ?? 0) - (a.priority ?? 0));
|
|
}
|
|
|
|
/**
|
|
* Remove rules for a specific tool.
|
|
*/
|
|
removeRulesForTool(toolName: string): void {
|
|
this.rules = this.rules.filter((rule) => rule.toolName !== toolName);
|
|
}
|
|
|
|
/**
|
|
* Get all current rules.
|
|
*/
|
|
getRules(): readonly PolicyRule[] {
|
|
return this.rules;
|
|
}
|
|
|
|
getCheckers(): readonly SafetyCheckerRule[] {
|
|
return this.checkers;
|
|
}
|
|
|
|
/**
|
|
* Add a new hook checker to the policy engine.
|
|
*/
|
|
addHookChecker(checker: HookCheckerRule): void {
|
|
this.hookCheckers.push(checker);
|
|
this.hookCheckers.sort((a, b) => (b.priority ?? 0) - (a.priority ?? 0));
|
|
}
|
|
|
|
/**
|
|
* Get all current hook checkers.
|
|
*/
|
|
getHookCheckers(): readonly HookCheckerRule[] {
|
|
return this.hookCheckers;
|
|
}
|
|
|
|
/**
|
|
* Check if a hook execution is allowed based on the configured policies.
|
|
* Runs hook-specific safety checkers if configured.
|
|
*/
|
|
async checkHook(
|
|
request: HookExecutionRequest | HookExecutionContext,
|
|
): Promise<PolicyDecision> {
|
|
// If hooks are globally disabled, deny all hook executions
|
|
if (!this.allowHooks) {
|
|
return PolicyDecision.DENY;
|
|
}
|
|
|
|
const context: HookExecutionContext =
|
|
'input' in request
|
|
? {
|
|
eventName: request.eventName,
|
|
hookSource: getHookSource(request.input),
|
|
trustedFolder:
|
|
typeof request.input['trusted_folder'] === 'boolean'
|
|
? request.input['trusted_folder']
|
|
: undefined,
|
|
}
|
|
: request;
|
|
|
|
// In untrusted folders, deny project-level hooks
|
|
if (context.trustedFolder === false && context.hookSource === 'project') {
|
|
return PolicyDecision.DENY;
|
|
}
|
|
|
|
// Run hook-specific safety checkers if configured
|
|
if (this.checkerRunner && this.hookCheckers.length > 0) {
|
|
for (const checkerRule of this.hookCheckers) {
|
|
if (hookCheckerMatches(checkerRule, context)) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.checkHook] Running hook checker: ${checkerRule.checker.name} for event: ${context.eventName}`,
|
|
);
|
|
try {
|
|
// Create a synthetic function call for the checker runner
|
|
// This allows reusing the existing checker infrastructure
|
|
const syntheticCall = {
|
|
name: `hook:${context.eventName}`,
|
|
args: {
|
|
hookSource: context.hookSource,
|
|
trustedFolder: context.trustedFolder,
|
|
},
|
|
};
|
|
|
|
const result = await this.checkerRunner.runChecker(
|
|
syntheticCall,
|
|
checkerRule.checker,
|
|
);
|
|
|
|
if (result.decision === SafetyCheckDecision.DENY) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.checkHook] Hook checker denied: ${result.reason}`,
|
|
);
|
|
return PolicyDecision.DENY;
|
|
} else if (result.decision === SafetyCheckDecision.ASK_USER) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.checkHook] Hook checker requested ASK_USER: ${result.reason}`,
|
|
);
|
|
// For hooks, ASK_USER is treated as DENY in non-interactive mode
|
|
return this.applyNonInteractiveMode(PolicyDecision.ASK_USER);
|
|
}
|
|
} catch (error) {
|
|
debugLogger.debug(
|
|
`[PolicyEngine.checkHook] Hook checker failed: ${error}`,
|
|
);
|
|
return PolicyDecision.DENY;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Default: Allow hooks
|
|
return PolicyDecision.ALLOW;
|
|
}
|
|
|
|
private applyNonInteractiveMode(decision: PolicyDecision): PolicyDecision {
|
|
// In non-interactive mode, ASK_USER becomes DENY
|
|
if (this.nonInteractive && decision === PolicyDecision.ASK_USER) {
|
|
return PolicyDecision.DENY;
|
|
}
|
|
return decision;
|
|
}
|
|
}
|