Input Validation

Kind: mechanism

Layer: Security Core

Record: architecture:input-validation

Severity: mandatory

Scope: API, boundary, function

Canonical: Ontology

A mechanism that checks external input against a schema at the boundary before core logic uses it.

Listed in Architecture principles, after Attribute-Based Access Control (ABAC) and before Output Encoding.

Requires

• Validation Rules
• Schema

Reinforces

• Security
• Correctness

Enables

• Fail Fast

Conflicts with

• Trusting External Input

In tension with

• Input Flexibility

Tensions

• Input Validation / Input Flexibility

Contracts

• Boundary Validation Over Unvalidated Input

Violated by

• Trusting External Input

Refactored by

• Schema Validation

Severity

• mandatory

Category

• Security / Privacy / Compliance / Governance

Required by

• Preconditions
• Defensive Programming

Refactors

• Defensive Programming
• Security by Design

Reinforced by

• Parameterized Queries

Linked from

• Systems built around a model
• Contracts / Interfaces / Compatibility
• Correctness / Determinism / Verification
• Error Handling / Resilience
• Security / Privacy / Compliance / Governance
• Core Vocabulary
• Quality Attributes
• Security Privacy Compliance
• Architectural Rules
• Severity levels
• The resolutions