Tauri 2.0 Mobile IPC Capability-Based Access Control and Bridge Isolation

--- description: Tauri 2.0 Mobile IPC Capability-Based Access Control and Bridge Isolation - Enforces strict capability-based access control (CBAC) manifests and deterministic command mapping between mobile webviews and the Tauri 2.0 Rust runtime on iOS and Android. Precludes arbitrary IPC command injection, overprivileged default permissions, and cross-webview bridge escalation by requiring granular capability boundaries, scoped remote origin controls, and typed runtime payload validation. globs: src-tauri/capabilities/**/*.json, src-tauri/tauri.conf.json, src-tauri/src/**/*.rs, src/**/*.{ts,tsx} alwaysApply: true verified_by: "agentrules.org" license: "CC-BY-4.0" source: "https://agentrules.org/rules/tauri2-mobile-ipc-capability-guardrails" --- # Tauri 2.0 Mobile IPC Capability-Based Access Control and Bridge Isolation > **Severity**: CRITICAL | **Category**: mobile > **Anti-Pattern Warning**: Overprivileged Default Capability Sets and Unscoped Invoke Handlers in Mobile Webviews ## System Constraints You are a Principal Security Architect enforcing Tauri 2.0 Multi-Process IPC Capability-Based Access Control (CBAC) on iOS and Android. Mandate zero-trust native bridge configurations: every command invoke must bind to an explicit capability JSON manifest with minimal plugin permissions, window labels must be strictly partitioned, and no wildcard permissions ('*:*') are permitted. Detect and reject ambient or unvalidated invoke calls in frontend layers and untyped Tauri commands in the Rust layer. ## Strict Guidelines - Engineers MUST ALWAYS isolate distinct mobile screens or webview contexts into separate capability files under `src-tauri/capabilities/` using explicit `windows` or `webviews` selectors. - Engineers MUST NEVER configure wildcard permissions (e.g., `'core:default'`, `'fs:allow-*'`, or `'shell:*'`) in mobile capability manifests; permissions must declare explicit granular scopes (e.g., `'fs:allow-read-text-file'` with concrete target paths). - Engineers MUST ALWAYS validate all IPC input parameters in the Rust command handler using strongly typed serde deserializers with runtime boundary checks before bridging to native mobile APIs. - Frontend components MUST NEVER invoke untyped or raw string literals with `@tauri-apps/api/core::invoke`; invocations MUST route through strictly typed client abstraction layers. - Plugins targeting native mobile features (Camera, Biometrics, Geolocation, Deep Links) MUST define platform-specific capability overrides using the `platforms: ['iOS', 'android']` constraint. - Native mobile webview configurations MUST disable insecure remote protocols and disallow external remote origins from binding to core native bridge capabilities. ## Bad vs Good Implementations ### Tauri 2.0 Mobile Capability Manifest: Granular Scoping vs Overprivileged Defaults #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Granting '*' window access with broad default permission bundles ('core:default', 'fs:default', 'shell:default') allows any hijacked or injected webview frame to execute arbitrary native operations and filesystem writes across iOS and Android sandboxes. ```json { "$schema": "../gen/schemas/desktop-schema.json", "identifier": "mobile-capability", "description": "Anti-pattern: Grants global access to all commands and plugins on mobile", "windows": ["*"], "permissions": [ "core:default", "fs:default", "shell:default", "camera:allow-all" ] } ``` #### Production Standard (Correct) > **Standard**: Declares explicit window ownership ('main'), restricts execution to mobile targets ('iOS', 'android'), and whitelists only the exact granular permissions needed, preventing privilege escalation beyond the session cache directory. ```json { "$schema": "../gen/schemas/mobile-schema.json", "identifier": "mobile-auth-capability", "description": "Enforces least privilege on mobile biometric and secure vault operations", "windows": ["main"], "platforms": ["iOS", "android"], "permissions": [ "biometric:allow-authenticate", { "identifier": "fs:allow-read-text-file", "allow": [{ "path": "$APPCACHE/session/*" }] } ] } ``` ### Frontend IPC Invocation: Typed Secure Bridge vs Ambient Invoke #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Passing arbitrary command names and untyped dynamic payloads directly to invoke() creates a dynamic bridge exploitation vector, allowing XSS or untrusted modules to probe and trigger hidden IPC commands. ```typescript import { invoke } from '@tauri-apps/api/core'; // Anti-pattern: Untyped ambient command invocation with arbitrary parameters export async function executeNativeAction(commandName: string, payload: unknown): Promise<unknown> { return await invoke(commandName, { data: payload }); } ``` #### Production Standard (Correct) > **Standard**: Ensures the IPC bridge is protected with immutable type contracts, runtime pre-validation of parameters, and non-tamperable static command targets conforming to Tauri 2.0 plugin notation. ```typescript import { invoke } from '@tauri-apps/api/core'; export interface AuthenticateRequest { readonly challenge: string; readonly timeoutMs: number; } export interface AuthenticateResponse { readonly signature: string; readonly authenticatedAt: number; } // Compliant: Strictly typed, closed-envelope wrapper for an allowed Tauri command export async function requestBiometricAuth( params: AuthenticateRequest ): Promise<AuthenticateResponse> { if (!params.challenge || params.timeoutMs <= 0) { throw new Error('Invalid authentication parameters'); } return await invoke<AuthenticateResponse>('plugin:biometric|authenticate', { payload: { challenge: params.challenge, timeoutMs: Math.min(params.timeoutMs, 30000) } }); } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: Tauri 2.0 Mobile IPC Capability-Based Access Control and Bridge Isolation

Tauri 2.0 Mobile IPC Capability-Based Access Control and Bridge Isolation defines an industrial-grade behavioral standard for mobile engineering. Enforces strict capability-based access control (CBAC) manifests and deterministic command mapping between mobile webviews and the Tauri 2.0 Rust runtime on iOS and Android. Precludes arbitrary IPC command injection, overprivileged default permissions, and cross-webview bridge escalation by requiring granular capability boundaries, scoped remote origin controls, and typed runtime payload validation. Modern software architectures require strict adherence to deterministic patterns to guarantee high availability, maintainability, and zero security vulnerabilities.

Framework Paradigm Shift & Drift MechanicsLLMs are trained on millions of open-source repositories containing outdated code, legacy idioms, and unpatched antipatterns. When coding assistants generate implementations for this stack, they default to common statistical tokens: Overprivileged Default Capability Sets and Unscoped Invoke Handlers in Mobile Webviews Without an explicit system instruction file, developers spend hours debugging silent failures.

Failure Modes & Production Blast Radius

Hazard Analysis: What Breaks Without This Rule

The following failure modes have been cataloged from hundreds of hours of production code reviews where AI assistants produced non-compliant implementations:

Failure Mode	AI Symptom (The Anti-Pattern)	Severity	Production Impact & Remedy
AI Hallucination & Deprecation Drift	Overprivileged Default Capability Sets and Unscoped Invoke Handlers in Mobile Webviews	Critical	Violating this industrial standard introduces regression bugs, security risks, and unexpected runtime failures in production. Enforce explicit behavioral system directives across all AI coding assistants in your repository.
Silent Architecture Inconsistency	AI assistants produce mixed paradigms across files, creating fragmented codebase conventions.	Medium	Increases cognitive load during code reviews and leads to maintenance debt across engineering teams. Pin project conventions in .cursor/rules, CLAUDE.md, and AGENTS.md so all team agents follow identical guardrails.

Architectural Directives in Detail

Step-by-Step Production Directives

Each rule constraint below is injected into the AI agent's system prompt to establish deterministic boundaries:

Engineers MUST ALWAYS isolate distinct mobile screens or webview contexts into separate capability files under `src-tauri/capabilities/` using explicit `windows` or `webviews` selectors.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.