EN-304-617_v0.0.6.md

**Fail Criteria**: Non-allowlisted APIs accessible OR reflection exposes unapproved methods OR dynamic invocation bypasses allowlist OR bridge mutable

**Evidence**: Bridge configuration showing explicit allowlist, reflection API output, method invocation logs showing blocked calls, immutability testing results, security review documentation for allowlisted APIs

**References**:

- OWASP API Security: https://owasp.org/www-project-api-security/
- Principle of Least Privilege: https://csrc.nist.gov/glossary/term/least_privilege
- Android WebView Interface Security: https://developer.android.com/reference/android/webkit/WebView#addJavascriptInterface(java.lang.Object,%20java.lang.String)
- Secure JavaScript Bridge Design: https://www.electronjs.org/docs/latest/tutorial/context-isolation

### Assessment: EMB-REQ-37 (Minimal and documented bridge API allowlist at EMB-1)

**Reference**: EMB-REQ-37 - Bridge API allowlist shall be minimal and documented at EMB-1 capability level

**Given**: A conformant embedded browser with EMB-1 capability (limited JavaScript bridge with explicit allowlist)

**Task**: JavaScript bridge security requires minimizing exposed API surface to reduce attack vectors, limit exploit potential, and simplify security review. Each exposed API creates opportunities for parameter injection, logic bugs, race conditions, and privilege escalation. Comprehensive documentation with security implications, threat models, input constraints, and usage examples enables security assessment, developer guidance, and audit compliance. Minimal API surface with complete documentation balances functionality needs with security risk management.

**Verification**:

1. Review complete bridge API allowlist and count exposed methods/functions → Complete API inventory documented
2. For each exposed API, verify security documentation exists explaining: purpose, parameters, return values, security implications, threat model → Each API has security documentation
3. Verify exposed APIs represent minimum necessary for application functionality → Security docs include threat models
4. Review application code and confirm all exposed bridge APIs are actually used → API surface justified as minimal
5. Identify any exposed APIs that are unused and flag for removal → No unused APIs exposed
6. Verify documentation includes input validation requirements for each API → Input validation requirements documented
7. Test that developers can understand API security implications from documentation alone → Security implications clearly explained
8. Verify threat model documentation covers potential attack vectors for each API → Attack vectors identified per API
9. Confirm documentation includes safe usage examples and anti-patterns to avoid → Safe usage examples provided
10. Verify security review sign-off exists for the API surface → Security review approval documented

**Pass Criteria**: API surface minimal and justified AND complete security documentation AND threat models per API AND security review approved

**Fail Criteria**: Excessive API surface OR missing documentation OR no threat models OR unused APIs exposed OR no security review

**Evidence**: Bridge API inventory with justifications, security documentation for each API, threat model documents, usage analysis showing API necessity, security review approval records

**References**:

- Attack Surface Reduction: https://csrc.nist.gov/glossary/term/attack_surface
- Threat Modeling: https://owasp.org/www-community/Threat_Modeling
- API Documentation Best Practices: https://swagger.io/specification/
- OWASP API Security: https://owasp.org/www-project-api-security/

### Assessment: EMB-REQ-38 (Bidirectional bridge security controls at EMB-2)

**Reference**: EMB-REQ-38 - Bidirectional bridge calls shall maintain same security controls in both directions at EMB-2 capability level

**Given**: A conformant embedded browser with EMB-2 capability (extended JavaScript bridge with bidirectional communication)

**Task**: Bidirectional JavaScript bridges enable both web-to-native and native-to-web communication, creating dual attack surfaces where malicious web content can exploit native-to-web callbacks and compromised native code can exploit web-to-native handlers. Asymmetric security controls create vulnerabilities where attackers bypass strict web-to-native validation by exploiting weaker native-to-web callback validation. Symmetric security enforcement with identical validation, logging, rate limiting, and permission checks in both directions prevents directional exploitation and maintains consistent security posture.

**Verification**:

1. Document all bidirectional bridge APIs (web-to-native calls and native-to-web callbacks) → Bidirectional APIs fully documented
2. Test input validation on web-to-native calls and document validation rules → Web-to-native calls validated comprehensively
3. Test input validation on native-to-web callbacks and verify identical validation strictness → Native-to-web callbacks equally validated
4. Compare validation, sanitization, and type checking between directions → Validation rules identical in strictness
5. Verify logging is comprehensive for both web-to-native and native-to-web communications → Logging comprehensive for both directions
6. Test rate limiting applies equally to both communication directions → Rate limiting symmetric
7. Verify permission checks enforced symmetrically → Permission checks enforced both ways
8. Attempt to bypass web-to-native validation by exploiting native-to-web callback path → Callback path cannot bypass validation
9. Test that callbacks cannot be used to inject unvalidated data into web context → Callbacks do not inject unvalidated data
10. Verify security audit events generated for both communication directions → Audit events generated for all communications

**Pass Criteria**: Validation symmetric across directions AND logging comprehensive for both AND rate limiting equal AND no bypass via callback path

**Fail Criteria**: Asymmetric validation OR logging gaps in one direction OR rate limiting inconsistent OR callback path bypasses controls

**Evidence**: Bidirectional API documentation, validation rule comparison, logging configuration showing symmetry, rate limiting policy analysis, bypass attempt test results, security audit logs

**References**:

- Secure IPC Design: https://chromium.googlesource.com/chromium/src/+/master/docs/security/mojo.md
- Bidirectional Communication Security: https://www.electronjs.org/docs/latest/tutorial/message-ports
- Input Validation: https://cheatsheetseries.owasp.org/cheatsheets/Input_Validation_Cheat_Sheet.html
- Defense in Depth: https://csrc.nist.gov/glossary/term/defense_in_depth

### Assessment: EMB-REQ-39 (Web content callback handler validation at EMB-2)

**Reference**: EMB-REQ-39 - Web content callback handlers shall be validated before invocation at EMB-2 capability level

**Given**: A conformant embedded browser with EMB-2 capability (extended JavaScript bridge with bidirectional communication)

**Task**: Native-to-web callbacks invoke JavaScript functions provided by web content, creating code injection and XSS risks if callbacks execute attacker-controlled functions or pass unvalidated data. Without strict validation, malicious web content registers callback handlers that exploit native invocation context, inject payloads through callback parameters, or leverage privileged execution timing. Handler validation with type checking, origin verification, parameter sanitization, and safe invocation patterns prevents callback-based attacks while enabling legitimate bidirectional communication.

**Verification**:

1. Register web content callback handler with JavaScript bridge → Callback existence validated before invocation
2. Trigger native-to-web callback from host application → Non-function callbacks rejected or handled safely
3. Verify native code validates callback handler exists and is a function before invocation → Callback parameters validated on native side
4. Test registering non-function callback and verify native code rejects or handles safely → Type checking enforced for complex objects
5. Verify callback parameters are validated and sanitized on native side before passing to web → Callbacks cannot access privileged state
6. Test passing complex objects through callbacks and confirm type checking enforced → Error handling prevents stack trace exposure
7. Attempt to register callback that accesses privileged global state and verify isolation maintained → Callbacks execute in restricted context
8. Test callback error handling and confirm errors don't expose native stack traces → Origin verification performed before invocation
9. Verify callbacks execute in restricted context without elevated privileges → Callback invocation logged for audit
10. Test that callback invocation includes origin verification → Malicious callbacks detected and blocked

**Pass Criteria**: Callbacks validated before invocation AND parameters sanitized AND error handling safe AND origin verification performed

**Fail Criteria**: Callbacks invoked without validation OR parameters unsanitized OR errors expose details OR no origin verification

**Evidence**: Callback registration and invocation code review, parameter validation testing, error handling analysis, origin verification logs, malicious callback detection results

**References**:

- Callback Security: https://www.electronjs.org/docs/latest/tutorial/security#17-validate-the-options-of-the-webcontents-opendevtools-call
- XSS Prevention: https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html
- Safe JavaScript Invocation: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/call
- Input Validation: https://cheatsheetseries.owasp.org/cheatsheets/Input_Validation_Cheat_Sheet.html

### Assessment: EMB-REQ-40 (Bridge message queuing with integrity protection at EMB-2)

**Reference**: EMB-REQ-40 - Bridge shall implement message queuing with integrity protection at EMB-2 capability level

**Given**: A conformant embedded browser with EMB-2 capability (extended JavaScript bridge with bidirectional communication)

**Task**: Asynchronous JavaScript bridge communication requires message queuing to decouple sender and receiver timing, but queues create attack surfaces for message tampering, injection, reordering, and replay attacks. Without integrity protection, attackers intercept queued messages to modify parameters, inject malicious messages, reorder operations to cause logic bugs, or replay messages to duplicate actions. Authenticated message queuing with sequence numbers, cryptographic MACs, and queue integrity verification prevents message manipulation while enabling reliable asynchronous communication.

**Verification**:

1. Trigger asynchronous JavaScript bridge communication requiring message queuing → Messages include sequence numbers or timestamps
2. Verify messages include sequence numbers or timestamps for ordering → Tampering detected through integrity checks
3. Attempt to tamper with queued message content and verify integrity check detects modification → Injected messages rejected due to authentication failure
4. Test message injection into queue and verify authentication prevents acceptance → Reordering detected and handled safely
5. Attempt to reorder messages in queue and verify sequence validation detects anomaly → Replay attacks prevented by sequence/nonce validation
6. Test message replay attack and verify sequence/nonce checking prevents duplicate processing → Cryptographic integrity protection used (MAC/signature)
7. Verify queue implementation uses cryptographic integrity protection (MAC, signature) → Queue overflow handled securely
8. Test queue overflow scenarios and verify graceful degradation without security compromise → Queue not manipulable by web content
9. Verify message queue is not accessible to web content for direct manipulation → Integrity failures logged as security events
10. Test that queue integrity failures trigger security events and logging → Queue implementation resists race conditions

**Pass Criteria**: Messages integrity protected AND sequence validation enforced AND tampering detected AND replay prevention implemented

**Fail Criteria**: No integrity protection OR sequence validation absent OR tampering undetected OR replay attacks succeed

**Evidence**: Message format documentation showing integrity fields, tampering test results, injection attempt logs, replay attack prevention verification, queue implementation security review

**References**:

- Message Queue Security: https://www.rabbitmq.com/security.html
- HMAC Integrity Protection: https://csrc.nist.gov/projects/hash-functions
- Replay Attack Prevention: https://cheatsheetseries.owasp.org/cheatsheets/Cryptographic_Storage_Cheat_Sheet.html
- Secure IPC: https://chromium.googlesource.com/chromium/src/+/master/docs/security/mojo.md

### Assessment: EMB-REQ-41 (Bridge traffic anomaly monitoring at EMB-2)

**Reference**: EMB-REQ-41 - Host shall monitor bridge traffic for anomalies at EMB-2 capability level

**Given**: A conformant embedded browser with EMB-2 capability (extended JavaScript bridge with bidirectional communication)

**Task**: JavaScript bridge traffic exhibits predictable patterns during normal application usage, enabling anomaly detection to identify attacks, compromised content, or exploited vulnerabilities. Monitoring for rate anomalies, suspicious method sequences, unusual parameters, or exploit patterns enables early attack detection and incident response. Without traffic monitoring, attackers exploit bridges repeatedly, probe for vulnerabilities, or exfiltrate data without detection. Real-time anomaly detection with baseline profiling, statistical analysis, and automated alerting prevents prolonged bridge exploitation.

**Verification**:

1. Establish baseline bridge traffic profile during normal application usage → Baseline traffic profile established
2. Configure anomaly detection with thresholds for: message rate, method frequency, parameter patterns, error rates → Anomaly detection thresholds configured
3. Trigger normal bridge usage and verify no false positive alerts → Normal usage generates no false positives
4. Simulate attack scenarios: rapid API calls exceeding rate limits, unusual method combinations, malformed parameters → Attack scenarios detected reliably
5. Verify anomaly detection system identifies and alerts on attack traffic → Alerts include investigation context
6. Test that alerts include sufficient context for investigation (origin, methods called, parameters, timing) → SIEM integration functional
7. Verify anomaly detection integrates with application security monitoring/SIEM → Automated responses implemented
8. Test automated responses to anomalies (throttling, blocking, enhanced logging) → Baseline adapts to usage changes
9. Verify baseline profiles updated automatically to reflect legitimate usage changes → Monitoring overhead acceptable
10. Test that monitoring performance overhead is acceptable → Security team receives actionable alerts

**Pass Criteria**: Anomaly detection functional AND attack scenarios detected AND false positives minimal AND automated alerting works

**Fail Criteria**: No anomaly detection OR attacks undetected OR excessive false positives OR no alerting integration

**Evidence**: Baseline traffic profile documentation, anomaly detection configuration, attack simulation results showing detection, alert samples, SIEM integration logs, performance impact analysis

**References**:

- Security Monitoring: https://www.sans.org/white-papers/36472/
- SIEM Integration: https://owasp.org/www-community/Log_Injection
- Behavioral Analysis: https://csrc.nist.gov/publications/detail/sp/800-94/final

### Assessment: EMB-REQ-42 (Enterprise bridge API policy configuration at EMB-2)

**Reference**: EMB-REQ-42 - Enterprise administrators shall be able to configure bridge API policies at EMB-2 capability level

**Given**: A conformant embedded browser with EMB-2 capability supporting enterprise policy management

**Task**: Enterprise deployments require centralized control over JavaScript bridge capabilities to enforce organizational security standards, prevent data exfiltration, comply with regulations, and manage risk. Without policy controls, users or developers expose sensitive APIs that violate corporate security policies, grant excessive privileges to web content, or enable unauthorized native functionality. Enterprise policy integration with API allowlist management, permission restrictions, and audit requirements enables IT governance over bridge security posture.

**Verification**:

1. Access enterprise policy configuration interface (MDM, configuration profile, policy file) → Enterprise policy interface accessible to IT administrators
2. Configure policy to restrict bridge API allowlist to specific approved methods → API allowlist restrictions enforceable via policy
3. Deploy policy to application and verify restricted methods are inaccessible to web content → Restricted APIs blocked with clear errors
4. Test that web content attempting to access policy-blocked APIs receives clear errors → Audit logging requirement enforceable
5. Configure policy requiring audit logging for all bridge communications → Logging cannot be disabled when policy requires it
6. Verify policy-mandated logging cannot be disabled by application developers → Rate limits configurable and enforced
7. Configure policy setting maximum rate limits for bridge API calls → Bridge functionality can be disabled by policy
8. Test that rate limits are enforced per policy configuration → Policy changes effective without recompilation
9. Verify policy can completely disable bridge functionality if required → Policy violations logged to enterprise monitoring
10. Test that policy changes take effect without requiring application recompilation → Administrators can audit current bridge configuration

**Pass Criteria**: Enterprise policies enforced AND API restrictions work AND logging mandatory when required AND policy updates dynamic

**Fail Criteria**: Policies not enforced OR API restrictions bypassed OR logging can be disabled OR policy updates require recompilation

**Evidence**: Enterprise policy configuration documentation, API restriction enforcement testing, audit logging verification, rate limit enforcement analysis, policy update procedures, compliance reports

**References**:

- Enterprise Mobile Management: https://developer.apple.com/documentation/devicemanagement
- Android Enterprise: https://developers.google.com/android/work
- Mobile Application Management: https://www.microsoft.com/en-us/security/business/threat-protection/mobile-application-management
- Security Policy Enforcement: https://csrc.nist.gov/glossary/term/policy_enforcement

### Assessment: EMB-REQ-43 (Core security boundaries preserved at EMB-3)

**Reference**: EMB-REQ-43 - Full integration shall not bypass core security boundaries at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability (full integration with native capabilities)

**Task**: Even with extensive native integration at EMB-3, fundamental security boundaries should remain intact to prevent complete application compromise. Core boundaries include: renderer process isolation from host process memory, web content sandboxing, origin-based security policies, and cryptographic key isolation. Bypassing these boundaries through bridge integration enables attackers who compromise web content to escalate directly to host privileges, access other origins' data, or extract cryptographic material. Maintaining core boundaries while enabling integration preserves defense-in-depth and limits exploit impact.

**Verification**:

1. Verify renderer process isolation maintained even with extensive bridge integration → Renderer process isolation intact
2. Test that web content cannot access host process memory directly through bridge APIs → Host process memory inaccessible from web content
3. Verify origin-based security model enforced (same-origin policy, CORS) despite native integration → Same-origin policy enforced
4. Test that bridge APIs cannot bypass origin restrictions to access other origins' data → Bridge cannot bypass origin restrictions
5. Verify cryptographic keys and credentials remain isolated from web content → Cryptographic keys isolated
6. Test that bridge cannot expose raw file system paths or handles that bypass sandbox → File system sandbox boundaries maintained
7. Verify CSP and other content security policies remain enforced → CSP enforced for all content
8. Test that full integration does not disable process-level sandboxing → Process sandboxing active
9. Verify network security policies (certificate validation, HSTS) cannot be bypassed through bridge → Network security policies cannot be bypassed
10. Test that bridge APIs cannot grant web content ability to load arbitrary native code → Native code loading restricted

**Pass Criteria**: Process isolation maintained AND origin policies enforced AND crypto keys isolated AND sandbox boundaries intact

**Fail Criteria**: Process isolation bypassed OR origin policies circumvented OR keys accessible OR sandbox escaped

**Evidence**: Process isolation testing, origin policy enforcement verification, cryptographic key isolation audit, sandbox boundary testing, security architecture review

**References**:

- Browser Security Architecture: https://www.chromium.org/developers/design-documents/multi-process-architecture/
- Process Isolation: https://www.chromium.org/developers/design-documents/site-isolation/
- Same-Origin Policy: https://developer.mozilla.org/en-US/docs/Web/Security/Same-origin_policy
- Defense in Depth: https://csrc.nist.gov/glossary/term/defense_in_depth

### Assessment: EMB-REQ-44 (User awareness of native capabilities at EMB-3)

**Reference**: EMB-REQ-44 - User shall be informed of all native capabilities granted to web content at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability (full integration with native capabilities)

**Task**: Users should understand which native capabilities are accessible to web content to make informed security and privacy decisions. Without transparency, malicious web content silently accesses camera, location, contacts, filesystem, or other sensitive native APIs through bridge integration, enabling surveillance, data theft, and privacy violations. Clear capability disclosure through permission prompts, settings interfaces, and usage indicators empowers users to grant appropriate access, revoke excessive permissions, and detect unauthorized native API usage.

**Verification**:

1. Identify all native capabilities accessible through JavaScript bridge at EMB-3 → Permission prompts appear for sensitive capabilities
2. Verify permission prompts appear when web content first requests sensitive native capabilities → Prompts clearly explain native access
3. Test that prompts clearly explain what native access is being granted (e.g., "camera access", "contact list access") → Settings show all granted capabilities
4. Access application settings and verify list of granted native capabilities is displayed → Capabilities explained in user-friendly terms
5. Verify settings interface explains each capability in user-friendly language → Web origins with capabilities visible
6. Test that users can see which web origins have been granted each capability → Active usage indicators function
7. Verify active capability usage indicators appear (e.g., camera indicator when camera accessed) → Indicators show which content is active
8. Test that users can click indicators to see which web content is using capabilities → Grants persist across restarts
9. Verify capability grants are persistent and visible across application restarts → Documentation explains permissions model
10. Test that application documentation explains bridge capabilities and permissions model → Users can make informed decisions

**Pass Criteria**: Permission prompts clear AND settings show all capabilities AND usage indicators present AND documentation complete

**Fail Criteria**: No permission prompts OR settings incomplete OR no usage indicators OR missing documentation

**Evidence**: Permission prompt screenshots, settings interface documentation, usage indicator demonstration, capability grant persistence testing, user documentation review

**References**:

- Permission UX Best Practices: https://web.dev/permission-ux/
- Mobile Permission Models: https://developer.android.com/guide/topics/permissions/overview
- iOS Permission Model: https://developer.apple.com/design/human-interface-guidelines/privacy
- User Privacy Controls: https://www.w3.org/TR/privacy-controls/

### Assessment: EMB-REQ-45 (User permission review and revocation at EMB-3)

**Reference**: EMB-REQ-45 - User shall be able to review and revoke native API access at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability (full integration with native capabilities)

**Task**: Users should have granular control to review all granted native API permissions and revoke access to manage security posture and respond to threats. Without revocation capabilities, users cannot remove access from compromised web content, recover from accidental over-privileged grants, or adjust permissions as trust relationships change. Permission management interface with per-origin, per-capability revocation, immediate enforcement, and usage history enables user control, security hygiene, and privacy protection.

**Verification**:

1. Grant multiple native capabilities (camera, location, contacts, storage) to web content through bridge → All granted capabilities visible in settings
2. Access application permission management settings interface → Per-capability revocation functional
3. Verify interface lists all granted capabilities organized by web origin and capability type → Revocation takes effect immediately
4. Select individual capability and revoke it through settings → Web content receives clear errors after revocation
5. Immediately test that web content can no longer access revoked capability → Bulk revocation available per origin
6. Verify web content receives clear error when attempting to use revoked capability → Usage history displayed for capabilities
7. Test bulk revocation of all capabilities for a specific web origin → Revocations persist across restarts
8. Verify permission management shows usage history (when capabilities were last accessed) → Re-granting requires new user consent
9. Test that revocations persist across application restarts → No hidden or unrevocable capabilities exist
10. Verify revoked permissions require new user consent if web content requests again → Interface is user-friendly and accessible

**Pass Criteria**: All capabilities reviewable AND revocation immediate AND per-capability control AND usage history visible

**Fail Criteria**: Capabilities hidden OR revocation delayed OR only bulk revocation OR no usage history

**Evidence**: Permission management UI screenshots, revocation testing showing immediate effect, usage history exports, persistence verification, hidden capability audit

**References**:

- Android Permission Management: https://developer.android.com/training/permissions/requesting
- iOS Permission Management: https://developer.apple.com/documentation/uikit/protecting_the_user_s_privacy
- Permission Management UX: https://web.dev/permission-ux/
- User Privacy Controls: https://www.w3.org/TR/privacy-controls/

### Assessment: EMB-REQ-46 (Native integration audit documentation at EMB-3)

**Reference**: EMB-REQ-46 - All native integrations shall be documented and auditable at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability (full integration with native capabilities)

**Task**: Extensive native integration at EMB-3 creates complex attack surfaces requiring comprehensive documentation for security review, vulnerability assessment, compliance auditing, and risk management. Without documentation of exposed native APIs, security boundaries relaxed, and integration patterns used, security teams cannot assess risk, auditors cannot verify compliance, and incident responders cannot investigate breaches effectively. Complete architecture documentation with threat models, security reviews, API inventories, and integration justifications enables informed security governance and compliance verification.

**Verification**:

1. Review application security documentation for native integration architecture → Native integration architecture documented
2. Verify complete inventory of all native APIs exposed through JavaScript bridge → Complete API inventory available
3. Confirm each exposed API has security documentation including: purpose, parameters, threat model, mitigations → Per-API security documentation exists
4. Review threat model documentation covering bridge integration attack vectors → Threat models cover bridge integration
5. Verify security review records exist for native integration design and implementation → Security review records available
6. Test that runtime diagnostics expose current bridge configuration for auditing → Runtime diagnostics expose configuration
7. Verify enterprise administrators can access detailed integration documentation → Enterprise documentation comprehensive
8. Review code comments and confirm they explain security-critical integration points → Code comments explain security-critical sections
9. Verify integration patterns and security controls are documented with examples → Integration patterns documented with examples
10. Test that documentation is maintained and updated with application versions → Documentation current with application version

**Pass Criteria**: Complete API inventory AND per-API security docs AND threat models AND security review records

**Fail Criteria**: Incomplete inventory OR missing security docs OR no threat models OR no security reviews

**Evidence**: Security documentation collection, API inventory with security annotations, threat model documents, security review approval records, runtime configuration dumps

**References**:

- Secure Development Lifecycle: https://www.microsoft.com/en-us/securityengineering/sdl/
- Threat Modeling: https://owasp.org/www-community/Threat_Modeling
- Security Documentation: https://cheatsheetseries.owasp.org/cheatsheets/Security_Documentation_Checklist.html
- API Security: https://owasp.org/www-project-api-security/

### Assessment: EMB-REQ-47 (Enterprise native integration restrictions at EMB-3)

**Reference**: EMB-REQ-47 - Enterprise policies shall be able to restrict native integration scope at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability supporting enterprise policy management

**Task**: Enterprise environments require centralized control to restrict native integration capabilities that pose unacceptable risk to organizational security, intellectual property, or compliance. Without policy controls, users or developers expose unrestricted camera access, filesystem operations, contact data, or other sensitive capabilities that enable data exfiltration or violate corporate policies. Enterprise policy integration with capability blocking, API allowlisting, and permission restrictions enables IT security governance over native integration posture.

**Verification**:

1. Access enterprise policy configuration interface (MDM, configuration profile, policy file) → Enterprise policy interface accessible
2. Configure policy to block specific native capabilities organization-wide (e.g., camera, contact access) → Capability blocking enforceable
3. Deploy policy and verify blocked capabilities are inaccessible to all web content → Blocked capabilities inaccessible with clear errors
4. Test that web content attempting to access policy-blocked capabilities receives clear policy violation errors → Origin allowlisting functional for sensitive APIs
5. Configure policy to allowlist specific web origins for sensitive capabilities → Non-allowlisted origins denied access
6. Test that only allowlisted origins can access sensitive capabilities → Maximum permission scope enforceable
7. Configure policy to restrict maximum permission scope for all web content → Users cannot exceed policy limits
8. Verify users cannot grant permissions exceeding policy-defined maximum → Bridge can be fully disabled by policy
9. Test that policy can completely disable JavaScript bridge if required → Policy violations logged to enterprise systems
10. Verify policy violations are logged to enterprise security monitoring → Administrators can audit current integration configuration

**Pass Criteria**: Capability blocking enforced AND origin allowlisting works AND permission scope limits effective AND violations logged

**Fail Criteria**: Policies not enforced OR blocking bypassed OR allowlists ignored OR no violation logging

**Evidence**: Enterprise policy configuration documentation, capability blocking testing, origin allowlist verification, permission scope limit testing, policy violation logs

**References**:

- Enterprise Mobile Management: https://developer.apple.com/documentation/devicemanagement
- Android Enterprise Policies: https://developers.google.com/android/work/requirements
- Mobile Application Management: https://www.microsoft.com/en-us/security/business/threat-protection/mobile-application-management
- Enterprise Security Governance: https://csrc.nist.gov/glossary/term/security_governance


### Assessment: EMB-REQ-48 (No privileged content origin access)

**Reference**: EMB-REQ-48 - No content origin shall have privileged access at EMB-0 capability level

**Given**: A conformant embedded browser with EMB-0 capability (complete sandboxing)

**Task**: This assessment verifies that the embedded browser treats all content origins equally without privileged access, preventing scenarios where certain trusted origins bypass security controls. Without this requirement, developers create dangerous exceptions for "trusted" internal content that attackers exploit through DNS hijacking, content injection, or social engineering to gain elevated access.

**Verification**:

1. Load content from multiple different origins (https, file://, data:, blob:) → All content types load successfully
2. Verify each origin is subject to same-origin policy restrictions → SOP applies equally to all origins
3. Test that no origin can access other origins' storage (localStorage, cookies, IndexedDB) → Cross-origin storage access blocked
4. Confirm no origin can access host application objects or native APIs → Native API access blocked for all origins
5. Test that no origin receives elevated CSP policies or security exceptions → CSP applies uniformly
6. Verify no origin can bypass context isolation or sandboxing → Isolation applies to all content
7. Test that file:// URLs have same restrictions as remote content → file:// URLs properly restricted
8. Confirm data: and blob: URLs are sandboxed appropriately → data:/blob: URLs sandboxed
9. Verify no origin allowlist or trust configuration exists → No trust configuration present
10. Test that all content receives identical security boundary enforcement → Uniform security enforcement verified

**Pass Criteria**: All origins treated identically AND no privileged access granted AND no trust exceptions exist AND uniform security enforcement

**Fail Criteria**: Any origin receives privileged access OR trust allowlists exist OR security bypasses present OR inconsistent enforcement

**Evidence**: Multi-origin loading tests, SOP verification, storage isolation testing, native API access attempts, CSP policy analysis, context isolation verification

**References**:

- Same-Origin Policy: https://developer.mozilla.org/en-US/docs/Web/Security/Same-origin_policy
- Content Security Policy: https://www.w3.org/TR/CSP3/
- OWASP: Origin-Based Attacks: https://owasp.org/www-community/attacks/


### Assessment: EMB-REQ-49 (Strict CSP enforcement without exceptions)

**Reference**: EMB-REQ-49 - All CSP policies shall be strictly enforced without exceptions at EMB-0 capability level

**Given**: A conformant embedded browser with EMB-0 capability

**Task**: This assessment verifies that Content Security Policy enforcement has no exceptions, bypass mechanisms, or relaxation modes that attackers could exploit. Strict CSP enforcement prevents inline script execution, unsafe evaluations, and unauthorized resource loading that enable XSS and code injection attacks.

**Verification**:

1. Configure strict CSP policy (default-src 'none'; script-src 'strict-dynamic') → CSP policy configured
2. Attempt to execute inline JavaScript in HTML → Inline scripts blocked
3. Test eval(), Function(), and similar dynamic code execution → Dynamic code execution blocked
4. Try to load scripts from non-allowlisted origins → Unauthorized script loading blocked
5. Verify CSP violations are reported (if reporting configured) → CSP violations reported correctly
6. Test that no meta tag or header can weaken configured CSP → CSP cannot be weakened at runtime
7. Attempt to bypass CSP using data: URLs, javascript: URLs → CSP bypass attempts blocked
8. Verify unsafe-inline and unsafe-eval directives are rejected or warned → Unsafe directives rejected
9. Test that CSP applies to all frames and embedded content → CSP applies to all contexts
10. Confirm no developer mode or debug flag relaxes CSP enforcement → No CSP relaxation modes exist

**Pass Criteria**: All CSP violations blocked AND no runtime weakening possible AND no bypass mechanisms AND violations properly reported

**Fail Criteria**: CSP bypasses successful OR runtime weakening possible OR debug modes relax enforcement OR violations unreported

**Evidence**: CSP configuration documentation, inline script blocking tests, eval() attempt logs, CSP bypass testing results, violation report verification

**References**:

- CSP Level 3 Specification: https://www.w3.org/TR/CSP3/
- CSP Evaluator: https://csp-evaluator.withgoogle.com/
- Strict CSP Guide: https://web.dev/strict-csp/


### Assessment: EMB-REQ-50 (Trust allowlist immutability)

**Reference**: EMB-REQ-50 - Trust allowlist configuration shall be immutable after WebView initialization at EMB-1 capability level

**Given**: A conformant embedded browser with EMB-1 capability (selective trusted content)

**Task**: This assessment verifies that trust allowlist configuration cannot be modified after browser initialization, preventing runtime tampering where attackers inject configuration changes to add malicious origins to trusted allowlists. Immutability ensures that only deployment-time configuration controls trust relationships.

**Verification**:

1. Initialize embedded browser with trust allowlist configuration → Browser initialized with trust allowlist
2. Verify allowlisted origins are correctly trusted at initialization → Trust allowlist active
3. Attempt to add new origin to trust allowlist at runtime via API → Runtime modification blocked
4. Test JavaScript injection attempts to modify trust configuration → Configuration injection blocked
5. Verify configuration file/database cannot be modified while browser running → Configuration storage protected
6. Test that browser restart is required for configuration changes → Changes require restart
7. Attempt to bypass immutability using reflection or native debugging → Reflection attacks blocked
8. Verify allowlist stored in read-only memory region if possible → Memory protection verified
9. Test that even privileged/admin APIs cannot modify running allowlist → Admin APIs cannot modify running config
10. Confirm configuration integrity is verified on browser restart → Configuration integrity checked on restart

**Pass Criteria**: Configuration immutable at runtime AND API modifications blocked AND bypass attempts fail AND restart required for changes

**Fail Criteria**: Runtime modification possible OR APIs allow changes OR bypass successful OR no restart required

**Evidence**: Initialization configuration, runtime modification attempts, API security testing, memory protection analysis, restart behavior verification

**References**:

- Immutable Configuration Patterns: https://csrc.nist.gov/glossary/term/immutable
- Android WebView Security: https://developer.android.com/training/articles/security-config
- iOS WKWebView: https://developer.apple.com/documentation/webkit/wkwebview


### Assessment: EMB-REQ-51 (All EMB-1 requirements implemented)

**Reference**: EMB-REQ-51 - All EMB-1 requirements shall be implemented at EMB-2 capability level

**Given**: A conformant embedded browser claiming EMB-2 capability

**Task**: This assessment verifies that EMB-2 capability level properly includes all EMB-1 baseline requirements for selective trusted content, ensuring that advancing to more sophisticated trust models does not bypass foundational security controls. This prevents capability level confusion attacks where EMB-2 features are used without EMB-1 protections.

**Verification**:

1. Execute all EMB-REQ-17 verification steps (Certificate validation) → EMB-REQ-17 passes
2. Execute all EMB-REQ-18 verification steps (Pinning for allowlisted origins) → EMB-REQ-18 passes
3. Execute all EMB-REQ-19 verification steps (SRI for external resources) → EMB-REQ-19 passes
4. Execute all EMB-REQ-20 verification steps (Pin update mechanism) → EMB-REQ-20 passes
5. Execute all EMB-REQ-21 verification steps (Clear trust boundaries) → EMB-REQ-21 passes
6. Execute all EMB-REQ-22 verification steps (Trust decision logging) → EMB-REQ-22 passes
7. Execute all EMB-REQ-23 verification steps (Local content signature verification) → EMB-REQ-23 passes
8. Execute all EMB-REQ-24 verification steps (TLS version enforcement) → EMB-REQ-24 passes
9. Execute all EMB-REQ-50 verification steps (Allowlist immutability) → EMB-REQ-50 passes
10. Verify documentation explicitly states EMB-1 compliance maintained → EMB-1 compliance documented

**Pass Criteria**: All EMB-1 assessments pass AND no EMB-1 requirement bypassed AND documentation confirms compliance

**Fail Criteria**: Any EMB-1 assessment fails OR requirements bypassed at EMB-2 level OR compliance not documented

**Evidence**: Complete EMB-1 assessment results, EMB-2 capability documentation, compliance verification report

**References**:

- Security Capability Levels: See Section 5.8.3
- Defense in Depth: https://csrc.nist.gov/glossary/term/defense_in_depth


### Assessment: EMB-REQ-52 (Pin configuration immutability)

**Reference**: EMB-REQ-52 - Pin configuration shall be immutable at runtime at EMB-2 capability level

**Given**: A conformant embedded browser with EMB-2 capability (extended trust verification)

**Task**: This assessment verifies that certificate pinning configuration cannot be modified after browser initialization, preventing runtime attacks where adversaries remove or replace certificate pins to enable man-in-the-middle attacks against pinned origins. Immutability ensures pinning integrity throughout browser lifetime.

**Verification**:

1. Initialize browser with certificate pinning configuration → Browser initialized with pins
2. Verify pins are correctly enforced for configured origins → Pins enforced correctly
3. Attempt to remove pin for specific origin at runtime → Pin removal blocked
4. Try to modify pin values (hash, public key) at runtime → Pin modification blocked
5. Test JavaScript injection to alter pin configuration → Injection attacks blocked
6. Verify pin storage is read-only after initialization → Pin storage protected
7. Attempt to add new pins at runtime → Runtime pin addition blocked
8. Test that pin configuration changes require browser restart → Changes require restart
9. Verify memory protection prevents pin tampering → Memory protection verified
10. Confirm pin integrity validation on startup → Integrity validation on startup

**Pass Criteria**: Pin configuration immutable at runtime AND modification attempts blocked AND restart required for changes AND integrity verified

**Fail Criteria**: Runtime modification possible OR pins can be removed OR bypass successful OR no integrity checks

**Evidence**: Pin configuration, runtime modification attempts, JavaScript injection tests, memory protection analysis, restart verification

**References**:

- Certificate Pinning: https://owasp.org/www-community/controls/Certificate_and_Public_Key_Pinning
- RFC 7469: Public Key Pinning Extension for HTTP: https://www.rfc-editor.org/rfc/rfc7469


### Assessment: EMB-REQ-53 (Pinning violation blocking)

**Reference**: EMB-REQ-53 - Content failing pinning validation shall be blocked with clear errors at EMB-2 capability level

**Given**: A conformant embedded browser with EMB-2 capability and certificate pinning configured

**Task**: This assessment verifies that certificate pinning violations immediately block content loading with clear user-facing error messages, preventing man-in-the-middle attacks while providing transparency about security enforcement. Silent failures or unclear errors leave users vulnerable or unable to troubleshoot legitimate issues.

**Verification**:

1. Configure certificate pin for test origin → Pin configured
2. Attempt to connect to origin with correct certificate → Connection succeeds with valid cert
3. Attempt connection with different valid certificate (wrong pin) → Connection blocked
4. Verify clear error message displayed to user → User receives clear error message
5. Confirm error message identifies pinning violation (not generic SSL error) → Pinning violation clearly identified
6. Test that no content from failed origin is displayed → No content displayed from blocked origin
7. Verify network connection is terminated immediately on violation → Connection terminated on violation
8. Test that pinning error is logged for debugging → Pinning violation logged
9. Attempt to force connection despite pinning failure → Override attempts blocked
10. Verify pinning failures trigger security events → Security events generated

**Pass Criteria**: Violations block content immediately AND clear errors displayed AND no content leaked AND violations logged

**Fail Criteria**: Content displays despite violation OR errors unclear/missing OR override possible OR no logging

**Evidence**: Pinning configuration, certificate mismatch tests, error message screenshots, connection logs, security event logs

**References**:

- Certificate Pinning Best Practices: https://owasp.org/www-community/controls/Certificate_and_Public_Key_Pinning
- User Error Communication: https://www.w3.org/WAI/WCAG21/Understanding/error-identification.html


### Assessment: EMB-REQ-54 (Pin rotation documentation and testing)

**Reference**: EMB-REQ-54 - Pin rotation procedures shall be documented and tested at EMB-2 capability level

**Given**: A conformant embedded browser with EMB-2 capability using certificate pinning

**Task**: This assessment verifies that certificate pin rotation procedures are documented, tested, and operational to prevent service outages when certificates expire or are rotated. Without tested rotation procedures, organizations face impossible choices between service availability and security when certificate changes occur.

**Verification**:

1. Review pin rotation documentation → Documentation exists and is comprehensive
2. Verify documentation covers emergency rotation scenarios → Emergency procedures documented
3. Confirm documentation includes timeline recommendations → Rotation timelines provided
4. Test documented rotation procedure with test pin → Rotation procedure works as documented
5. Verify backup pins are supported (RFC 7469 recommendation) → Backup pins supported
6. Test that old pins can be gracefully deprecated → Pin deprecation works
7. Verify rotation requires explicit deployment/update → Rotation requires explicit action
8. Test that rotation testing can be performed in staging environment → Staging testing supported
9. Confirm monitoring for upcoming certificate expirations → Expiration monitoring recommended
10. Verify rollback procedure documented if rotation fails → Rollback procedure documented

**Pass Criteria**: Procedures documented completely AND rotation tested successfully AND backup pins supported AND rollback possible

**Fail Criteria**: Documentation missing/incomplete OR rotation untested OR no backup pins OR no rollback plan

**Evidence**: Pin rotation documentation, rotation test results, backup pin configuration, staging test results, rollback procedure

**References**:

- RFC 7469: Public Key Pinning: https://www.rfc-editor.org/rfc/rfc7469
- Certificate Management Best Practices: https://csrc.nist.gov/publications/detail/sp/800-57-part-1/rev-5/final


### Assessment: EMB-REQ-55 (EMB-1 certificate validation baseline for remote content)

**Reference**: EMB-REQ-55 - Baseline EMB-1 certificate validation shall apply to all remote content at EMB-3 capability level

**Given**: A conformant embedded browser claiming EMB-3 capability (local/bundled content with cryptographic verification)

**Task**: This assessment verifies that EMB-3 implementations maintain EMB-1 certificate validation requirements for all remote content, preventing capability level confusion where local content verification replaces rather than supplements remote content security. Both local and remote content need appropriate security controls for hybrid deployments.

**Verification**:

1. Execute all EMB-REQ-17 verification steps for remote content → EMB-REQ-17 passes for remote content
2. Execute all EMB-REQ-18 verification steps for remote pinned origins → EMB-REQ-18 passes for remote content
3. Execute all EMB-REQ-19 verification steps for remote external resources → EMB-REQ-19 passes for remote resources
4. Execute all EMB-REQ-24 verification steps for remote TLS connections → EMB-REQ-24 passes for remote content
5. Verify local content signature verification does not disable remote validation → Remote validation remains active
6. Test hybrid deployment (local + remote) maintains separate validation → Separate validation confirmed
7. Confirm remote content cannot be validated using local signature mechanisms → Remote uses proper PKI validation
8. Verify documentation clearly states remote content requirements → Remote requirements documented
9. Test that EMB-3 certification does not bypass EMB-1 remote controls → EMB-1 controls not bypassed
10. Confirm capability level properly enforces both local AND remote security → Both security models enforced

**Pass Criteria**: All EMB-1 remote validations pass AND local verification supplements not replaces AND documentation clear AND both models enforced

**Fail Criteria**: EMB-1 remote validations fail OR local verification replaces remote OR documentation unclear OR controls bypassed

**Evidence**: Complete EMB-1 assessment results for remote content, hybrid deployment tests, documentation review, capability level verification

**References**:

- Security Capability Levels: See Section 5.8.3
- Hybrid Deployment Security: See EMB-3 Requirements


### Assessment: EMB-REQ-56 (Secure local content signature algorithms)

**Reference**: EMB-REQ-56 - Local content signature verification shall use secure algorithms (RSA-2048+, ECDSA P-256+) at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability supporting local/bundled content signature verification

**Task**: This assessment verifies that cryptographic signature verification for local content uses algorithms with adequate security strength, preventing attacks using weak cryptography (MD5, SHA1, RSA-1024) that modern attackers can break to forge content signatures and inject malicious local content.

**Verification**:

1. Review signature algorithm configuration and documentation → Algorithm requirements documented
2. Verify RSA signatures use minimum 2048-bit keys → RSA-2048+ enforced
3. Confirm ECDSA signatures use P-256 or stronger curves → ECDSA P-256+ enforced
4. Test that signatures using weak algorithms (RSA-1024, MD5, SHA1) are rejected → Weak algorithms rejected
5. Verify signature verification uses current cryptographic libraries → Current libraries used
6. Test that algorithm negotiation does not downgrade to weak algorithms → No downgrade attacks possible
7. Confirm hash algorithms are SHA-256 or stronger → SHA-256+ for hashing
8. Verify signature format prevents algorithm confusion attacks → Format prevents confusion
9. Test that signature verification fails clearly with weak algorithms → Clear failure messages for weak crypto
10. Confirm documentation recommends cryptographic best practices → Best practices documented

**Pass Criteria**: Strong algorithms enforced AND weak algorithms rejected AND no downgrade possible AND clear error messages

**Fail Criteria**: Weak algorithms accepted OR downgrade possible OR unclear errors OR outdated crypto libraries

**Evidence**: Algorithm configuration, weak algorithm rejection tests, library version verification, signature format documentation

**References**:

- NIST SP 800-57: Key Management Recommendations: https://csrc.nist.gov/publications/detail/sp/800-57-part-1/rev-5/final
- RFC 8446: TLS 1.3 Cryptographic Algorithms: https://www.rfc-editor.org/rfc/rfc8446


### Assessment: EMB-REQ-57 (Modified local content rejection)

**Reference**: EMB-REQ-57 - Modified local content shall fail signature verification and be rejected at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability verifying local/bundled content signatures

**Task**: This assessment verifies that any modification to locally stored or bundled content causes signature verification failure and content rejection, preventing tampered content execution where attackers modify local files to inject malicious code while signature checking is configured but ineffective.

**Verification**:

1. Deploy local content with valid signatures → Content loads successfully with valid signatures
2. Modify single byte in signed content file → Content modification detected
3. Attempt to load modified content → Modified content rejected
4. Verify clear error message indicates signature verification failure → Clear error message displayed
5. Confirm no partial content from failed file is executed → No partial execution
6. Test modification of content before signature check runs → Early modification detected
7. Attempt time-of-check-time-of-use (TOCTOU) race condition → TOCTOU attacks prevented
8. Verify signature failures are logged with details → Signature failures logged
9. Test that signature verification cannot be disabled at runtime → Verification cannot be disabled
10. Confirm fallback behavior is safe (no unsigned content execution) → Safe fallback behavior

**Pass Criteria**: All modifications detected AND content rejected AND clear errors AND TOCTOU prevented AND safe fallback

**Fail Criteria**: Modifications undetected OR modified content executes OR unclear errors OR TOCTOU possible OR unsafe fallback

**Evidence**: Signature verification logs, content modification tests, TOCTOU testing, error messages, fallback behavior verification

**References**:

- Code Signing Best Practices: https://csrc.nist.gov/glossary/term/code_signing
- TOCTOU Vulnerabilities: https://cwe.mitre.org/data/definitions/367.html


### Assessment: EMB-REQ-58 (Signing key protection from extraction)

**Reference**: EMB-REQ-58 - Signing keys for local content shall be protected from extraction at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability using code signing for local content

**Task**: This assessment verifies that private keys used to sign local content are protected from extraction via application vulnerabilities, ensuring that compromising the embedded browser does not provide attackers with signing keys to forge arbitrary signed content for distribution to other instances.

**Verification**:

1. Review key storage architecture and documentation → Key protection architecture documented
2. Verify signing keys are not embedded in browser application → Keys not embedded in browser
3. Confirm signing keys stored separately from browser deployment → Keys stored separately
4. Test that debugging/introspection cannot reveal signing keys → Keys not revealed via debugging
5. Verify only public keys are included in browser distribution → Only public keys included
6. Test that signature verification does not require private key access → Private keys not needed for verification
7. Confirm key management documentation separates signing from verification → Clear separation documented
8. Verify keys are protected during development/build process → Build process protections documented
9. Test that compromising browser instance does not expose keys → Browser compromise does not leak keys
10. Confirm key rotation capability exists for compromise scenarios → Key rotation procedures exist

**Pass Criteria**: Private keys never in browser AND extraction impossible AND only public keys distributed AND rotation possible

**Fail Criteria**: Private keys in browser OR extraction possible OR unclear key separation OR no rotation capability

**Evidence**: Key architecture documentation, code review, debugging tests, distribution package analysis, key management procedures

**References**:

- Key Management Best Practices: https://csrc.nist.gov/publications/detail/sp/800-57-part-1/rev-5/final
- Code Signing Certificate Security: https://casecurity.org/code-signing/


### Assessment: EMB-REQ-59 (Hybrid deployment strictest controls)

**Reference**: EMB-REQ-59 - Hybrid deployments (local + remote) shall maintain strictest security controls for each content type at EMB-3 capability level

**Given**: A conformant embedded browser with EMB-3 capability deployed with both local signed content and remote content

**Task**: This assessment verifies that hybrid deployments maintain appropriate security controls for both content types simultaneously, preventing security control confusion where local content verification weakens remote content validation or vice versa. Each content type needs controls appropriate to its threat model.

**Verification**:

1. Deploy browser with both local signed content and remote HTTPS content → Hybrid deployment functional
2. Verify local content undergoes signature verification → Local signature verification active
3. Confirm remote content undergoes certificate validation → Remote certificate validation active
4. Test that local content signature failure blocks only local content → Local failure isolated
5. Verify remote content certificate failure blocks only remote content → Remote failure isolated
6. Confirm local content cannot bypass CSP using signature validation → CSP applies to local content
7. Test that remote content cannot use local content trust assumptions → Trust models separate
8. Verify logging distinguishes local vs remote security events → Separate logging for each type
9. Test that mixed content policies apply correctly → Mixed content policies enforced
10. Confirm documentation clearly explains hybrid security model → Hybrid model documented

**Pass Criteria**: Both validation types active AND failures isolated correctly AND no trust confusion AND policies enforced independently

**Fail Criteria**: Validation types interfere OR failures affect wrong content type OR trust confusion exists OR policies not enforced

**Evidence**: Hybrid deployment configuration, separate validation testing, failure isolation tests, logging analysis, policy enforcement verification

**References**:

- Mixed Content Specification: https://www.w3.org/TR/mixed-content/
- Defense in Depth: https://csrc.nist.gov/glossary/term/defense_in_depth


## 6.9 Remote Data Processing Systems Security Assessments

This section covers assessment procedures for requirements RDPS-REQ-1 through RDPS-REQ-45, addressing secure remote data processing, encryption in transit and at rest, authentication and authorization, availability and disaster recovery, data minimization and protection, and user configuration security.

### Assessment: RDPS-REQ-1 (Offline functionality documentation)

**Reference**: RDPS-REQ-1 - Browser shall document product functionality when RDPS connectivity unavailable

**Given**: A conformant browser with RDPS-1 or higher capability

**Task**: Users and administrators should understand how browser functionality changes when remote data processing systems become unavailable due to network failures, service outages, or infrastructure issues. Without clear documentation of offline behavior, users cannot assess business continuity risk, plan for service disruptions, or make informed deployment decisions. Comprehensive documentation with feature availability matrices, degradation scenarios, data synchronization behavior, and recovery procedures enables informed risk management and operational planning.

**Verification**:

1. Review browser documentation for RDPS offline functionality coverage → Documentation covers offline functionality comprehensively
2. Verify documentation explains which features remain functional without RDPS connectivity → Feature availability matrix provided (online vs offline)
3. Confirm documentation lists features that become degraded or unavailable offline → Degraded features clearly identified
4. Test browser behavior when RDPS connectivity lost and verify it matches documentation → Actual behavior matches documented offline behavior
5. Verify documentation explains data synchronization behavior after connectivity restoration → Synchronization behavior explained
6. Test that users are notified when RDPS becomes unavailable → User notifications for RDPS unavailability documented
7. Verify documentation includes troubleshooting steps for RDPS connectivity issues → Troubleshooting guidance provided
8. Test that critical features identified in documentation continue functioning offline → Critical features function offline as documented
9. Verify documentation explains local data caching behavior during RDPS outages → Caching behavior explained
10. Confirm documentation describes maximum offline operation duration → Offline duration limits documented

**Pass Criteria**: Comprehensive offline documentation AND feature matrix provided AND behavior matches documentation AND user notifications described

**Fail Criteria**: Missing offline documentation OR no feature matrix OR behavior doesn't match docs OR no notification guidance

**Evidence**: Documentation review showing offline functionality coverage, feature availability matrix, offline behavior testing results, user notification examples, synchronization behavior documentation

**References**:

- NIST SP 800-160 Vol. 2: Systems Security Engineering - Cyber Resiliency: https://csrc.nist.gov/publications/detail/sp/800-160/vol-2/final
- Business Continuity Planning: https://www.iso.org/standard/75106.html
- Resilient System Design: https://owasp.org/www-project-resilient-system-design/

### Assessment: RDPS-REQ-2 (Data classification and inventory)

**Reference**: RDPS-REQ-2 - Browser shall define all data processed or stored in RDPS with data classification

**Given**: A conformant browser with RDPS-1 or higher capability

**Task**: Data classification is fundamental to RDPS security, enabling appropriate protection controls, compliance with regulations (GDPR, CCPA), and risk-informed security decisions. Without complete data inventory and classification, organizations cannot assess privacy risks, implement proportionate security controls, or demonstrate regulatory compliance. Comprehensive data catalog with sensitivity levels, data types, retention requirements, and processing purposes enables informed security governance and privacy protection.

**Verification**:

1. Review browser RDPS data inventory documentation → Complete data inventory exists
2. Verify inventory includes complete list of data types processed/stored remotely → All RDPS data types documented
3. Confirm each data type has assigned classification (public, internal, confidential, restricted) → Classification assigned to each type
4. Test that classification reflects actual sensitivity of data → Classification reflects actual sensitivity
5. Verify documentation explains purpose and necessity for each data type → Purpose documented for each data type
6. Confirm data inventory includes retention periods for each type → Retention periods specified
7. Review RDPS data flows and verify they match inventory → Data flows match inventory
8. Test that no undocumented data is transmitted to RDPS → No undocumented data transmission occurs
9. Verify classification system aligns with industry standards (ISO 27001, NIST) → Classification system follows standards
10. Confirm inventory is maintained and updated with product versions → Inventory kept current with product updates

**Pass Criteria**: Complete data inventory AND classification for all types AND purpose documented AND retention specified AND no undocumented data

**Fail Criteria**: Incomplete inventory OR missing classifications OR purpose undefined OR no retention periods OR undocumented data found

**Evidence**: Data inventory documentation, classification scheme, data flow diagrams, network traffic analysis showing only documented data, retention policy documentation

**References**:

- ISO/IEC 27001 Information Security Management: https://www.iso.org/standard/27001
- NIST SP 800-60 Guide for Mapping Types of Information: https://csrc.nist.gov/publications/detail/sp/800-60/vol-1-rev-1/final
- GDPR Data Protection: https://gdpr-info.eu/
- Data Classification Best Practices: https://www.sans.org/white-papers/36857/

### Assessment: RDPS-REQ-3 (Data criticality classification)

**Reference**: RDPS-REQ-3 - Browser shall classify criticality of all RDPS-processed data

**Given**: A conformant browser with RDPS-1 or higher capability

**Task**: Data criticality classification determines appropriate availability requirements, backup strategies, and disaster recovery priorities for RDPS data. Without criticality assessment, organizations cannot allocate resources appropriately, prioritize recovery efforts during incidents, or implement risk-proportionate protection controls. Criticality classification with availability requirements, recovery objectives (RTO/RPO), and business impact analysis enables effective business continuity and disaster recovery planning.

**Verification**:

1. Review browser RDPS data criticality classification documentation → Criticality classification exists for all data types
2. Verify each data type has assigned criticality level (critical, important, standard, low) → Criticality levels assigned systematically
3. Confirm criticality reflects business impact of data loss or unavailability → Business impact drives criticality assessment
4. Verify documentation includes Recovery Time Objective (RTO) for critical data → RTO specified for critical data
5. Confirm documentation specifies Recovery Point Objective (RPO) for critical data → RPO documented for critical data
6. Test that backup frequency aligns with RPO requirements → Backup frequency meets RPO
7. Verify high-availability mechanisms deployed for critical data → High-availability for critical data
8. Test data recovery procedures and verify they meet RTO targets → Recovery meets RTO targets
9. Confirm business impact analysis justifies criticality classifications → Business impact analysis documented
10. Verify criticality classifications updated with product functionality changes → Classifications updated with product changes

**Pass Criteria**: Criticality classification for all data AND RTO/RPO specified for critical data AND backup frequency appropriate AND recovery tested

**Fail Criteria**: Missing criticality classification OR no RTO/RPO specified OR inadequate backup frequency OR recovery fails RTO

**Evidence**: Criticality classification documentation, RTO/RPO specifications, business impact analysis, backup frequency configuration, recovery test results

**References**:

- NIST SP 800-34 Contingency Planning Guide: https://csrc.nist.gov/publications/detail/sp/800-34/rev-1/final
- ISO 22301 Business Continuity: https://www.iso.org/standard/75106.html
- Disaster Recovery Planning: https://www.ready.gov/business/implementation/IT

### Assessment: RDPS-REQ-4 (TLS 1.3 encryption for data transmission)

**Reference**: RDPS-REQ-4 - Browser shall encrypt all data transmissions to RDPS using TLS 1.3 or higher

**Given**: A conformant browser with RDPS-1 or higher capability

**Task**: Unencrypted RDPS communications expose data to eavesdropping, man-in-the-middle attacks, and credential theft, enabling attackers to intercept sensitive information, modify data in transit, or hijack sessions. TLS 1.3 provides strong encryption with perfect forward secrecy, modern cipher suites, and protection against downgrade attacks. Enforcing minimum TLS 1.3 for all RDPS communications prevents protocol vulnerabilities, ensures strong cryptographic protection, and maintains confidentiality and integrity of data transmission.

**Verification**:

1. Configure network monitoring to capture browser-RDPS traffic → All RDPS connections encrypted with TLS
2. Trigger RDPS operations requiring data transmission → TLS 1.3 or higher enforced
3. Analyze captured traffic and verify all connections use TLS → TLS 1.2 and lower rejected
4. Verify TLS version is 1.3 or higher (no TLS 1.2, 1.1, 1.0 allowed) → Modern cipher suites used
5. Confirm cipher suites used are TLS 1.3 compliant (AES-GCM, ChaCha20-Poly1305) → Perfect forward secrecy enabled
6. Test that browser rejects TLS 1.2 or lower connections to RDPS → Downgrade attacks prevented
7. Verify perfect forward secrecy (PFS) enabled through ephemeral key exchange → Certificate validation mandatory
8. Test that browser prevents TLS downgrade attacks → No plaintext transmission detected
9. Verify certificate validation enforced for RDPS endpoints → Handshake completes with TLS 1.3 parameters
10. Confirm no plaintext data transmission occurs → Connection parameters meet security requirements

**Pass Criteria**: TLS 1.3+ enforced for all RDPS AND older TLS rejected AND PFS enabled AND certificate validation mandatory

**Fail Criteria**: TLS 1.2 or lower allowed OR unencrypted transmissions OR no PFS OR certificate validation optional

**Evidence**: Network traffic captures showing TLS 1.3, TLS version enforcement testing, cipher suite analysis, downgrade attack test results, certificate validation verification

**References**:

- TLS 1.3 RFC 8446: https://www.rfc-editor.org/rfc/rfc8446
- NIST SP 800-52 Rev. 2 TLS Guidelines: https://csrc.nist.gov/publications/detail/sp/800-52/rev-2/final
- Mozilla TLS Configuration: https://wiki.mozilla.org/Security/Server_Side_TLS
- OWASP Transport Layer Protection: https://cheatsheetseries.owasp.org/cheatsheets/Transport_Layer_Protection_Cheat_Sheet.html

### Assessment: RDPS-REQ-5 (RDPS endpoint certificate validation)

**Reference**: RDPS-REQ-5 - Browser shall authenticate RDPS endpoints using certificate validation

**Given**: A conformant browser with RDPS-1 or higher capability

**Task**: RDPS endpoint authentication prevents man-in-the-middle attacks, server impersonation, and phishing attacks targeting remote data processing infrastructure. Without proper certificate validation, attackers can intercept RDPS communications, steal credentials, modify data, or redirect traffic to malicious servers. Comprehensive certificate validation with chain verification, revocation checking, hostname verification, and certificate pinning ensures authentic, trusted RDPS endpoints and prevents connection hijacking.

**Verification**:

1. Test RDPS connection with valid, trusted certificate and verify connection succeeds → Valid certificates accepted
2. Test with expired certificate and verify connection blocked with clear error → Expired certificates rejected
3. Test with self-signed certificate and confirm connection rejected → Self-signed certificates blocked
4. Test with certificate for wrong hostname and verify hostname verification fails → Hostname verification enforced
5. Test with revoked certificate and confirm revocation check prevents connection → Revocation checking performed
6. Verify certificate chain validation enforced (intermediate and root CAs verified) → Certificate chain validated
7. Test certificate pinning if implemented and verify pinned certificates required → Certificate pinning enforced (if implemented)
8. Attempt MITM attack with attacker-controlled certificate and verify detection → MITM attacks detected through certificate mismatch
9. Verify browser displays clear error messages for certificate validation failures → Clear error messages displayed
10. Test that users cannot bypass certificate errors for RDPS connections → Certificate errors not bypassable

**Pass Criteria**: Certificate validation enforced AND revocation checked AND hostname verified AND chain validated AND errors not bypassable

**Fail Criteria**: Invalid certificates accepted OR no revocation checking OR hostname not verified OR chain not validated OR errors bypassable

**Evidence**: Certificate validation test results, revocation checking logs, hostname verification testing, MITM attack prevention demonstration, error message screenshots

**References**:

- RFC 5280 X.509 Certificate Validation: https://www.rfc-editor.org/rfc/rfc5280
- RFC 6962 Certificate Transparency: https://www.rfc-editor.org/rfc/rfc6962
- OWASP Certificate Pinning: https://owasp.org/www-community/controls/Certificate_and_Public_Key_Pinning
- Certificate Validation Best Practices: https://csrc.nist.gov/publications/detail/sp/800-52/rev-2/final

### Assessment: RDPS-REQ-6 (Retry mechanisms with exponential backoff)

**Reference**: RDPS-REQ-6 - Browser shall implement retry mechanisms with exponential backoff for RDPS failures

**Given**: A conformant browser with RDPS-1 or higher capability

**Task**: RDPS connectivity failures are inevitable due to network issues, server outages, or rate limiting. Without intelligent retry mechanisms, browsers either fail immediately (poor user experience) or retry aggressively (amplifying outages, triggering rate limits). Exponential backoff with jitter provides graceful degradation by spacing retries progressively further apart, reducing server load during outages while maintaining eventual connectivity. Proper retry logic with maximum attempts, timeout bounds, and failure notification enables resilient RDPS operations.

**Verification**:

1. Simulate RDPS connectivity failure (network disconnection, server timeout) → Initial retry after short delay
2. Verify browser attempts initial retry after short delay (e.g., 1-2 seconds) → Exponential backoff applied to subsequent retries
3. Confirm subsequent retries use exponentially increasing delays (2s, 4s, 8s, 16s, etc.) → Jitter randomization prevents synchronized retries
4. Test that jitter is added to prevent thundering herd (randomized delay component) → Maximum retry attempts enforced
5. Verify maximum retry attempts limit exists (e.g., 5-10 attempts) → Total retry duration bounded
6. Confirm total retry duration has upper bound (e.g., maximum 5 minutes) → User notification after exhaustion
7. Test that user is notified after retry exhaustion → Manual retry option available
8. Verify browser provides manual retry option after automatic retries fail → Successful retry restores operation
9. Test that successful retry restores normal operation without user intervention → Retry state persists appropriately
10. Confirm retry state persists across browser restarts for critical operations → No infinite retry loops

**Pass Criteria**: Exponential backoff implemented AND jitter applied AND maximum attempts enforced AND user notified on failure

**Fail Criteria**: Linear retry timing OR no jitter OR infinite retries OR no user notification

**Evidence**: Retry timing logs showing exponential pattern, jitter analysis, maximum attempt enforcement testing, user notification screenshots, retry exhaustion behavior verification

**References**:

- Exponential Backoff Algorithm: https://en.wikipedia.org/wiki/Exponential_backoff
- AWS Architecture Best Practices: https://aws.amazon.com/architecture/well-architected/
- Google Cloud Retry Strategy: https://cloud.google.com/architecture/scalable-and-resilient-apps
- Circuit Breaker Pattern: https://martinfowler.com/bliki/CircuitBreaker.html

### Assessment: RDPS-REQ-7 (Local data caching for offline operation)

**Reference**: RDPS-REQ-7 - Browser shall cache critical data locally for offline operation

**Given**: A conformant browser with RDPS-1 or higher capability

**Task**: Local caching enables browser functionality continuation during RDPS outages by storing critical data locally for offline access. Without caching, RDPS unavailability renders browser features completely non-functional, creating poor user experience and business continuity risks. Intelligent caching with staleness policies, cache invalidation, and synchronization on reconnection balances offline functionality with data freshness and storage constraints.

**Verification**: