Pure.Authorization.OpenFGA.Model.Conditions 0.1.0-preview.0.1.0

Pure.Authorization.OpenFGA.Model.Conditions

IBool condition types over OpenFGA authorization models for the Pure ecosystem.

Overview

Pure.Authorization.OpenFGA.Model.Conditions provides composable IBool condition types over the interfaces of Pure.Authorization.OpenFGA.Model.Abstractions. They check identifiers against OpenFGA's syntax, check an authorization model for internal consistency, and check a relationship tuple for conformance to a model. Each condition is a lazy, immutable value object that implements IBool from Pure.Primitives.Abstractions.

Every rule comes from OpenFGA's own validation, and each condition cites where OpenFGA enforces it. The citations point at openfga/api@c0650ce and openfga/openfga@v1.22.0.

IBool valid = new ValidAuthorizationModelCondition(model);

IBool assignable = new AssignableTupleCondition(model, tuple);

if (valid.BoolValue && assignable.BoolValue)
{
    // The model passes every rule listed below, and the tuple conforms to it.
}

Conditions

Lengths given in code points count Unicode code points, as OpenFGA's Go regular expressions do. In those patterns \s is Go's [\t\n\f\r ]. A control character is U+0000 to U+001F or U+007F to U+009F (Go's unicode.IsControl).

Identifier syntax

Model lookups

Model consistency

Tuple conformance

Not checked

These OpenFGA rules are not checked, so a condition can hold for input that OpenFGA rejects:

• Entrypoints and cycles. NewAndValidate rejects relations that no tuple can ever satisfy (hasEntrypoints, ErrNoEntrypoints) and relations that resolve through a cycle (HasCycle, ErrCycle). Neither is checked.
• CEL expressions. OpenFGA compiles each condition's expression (EvaluableCondition.Compile), so it must parse, type-check to bool, and use parameter names that are valid CEL identifiers. Only the expression's 512-byte limit is checked.
• Context values. OpenFGA converts each context value to its parameter's type (CastContextToTypedParameters) and rejects control characters in context keys and string values (ValidateStruct). Only the context keys are checked.
• Server limits. The maximum number of types per model (MaxTypesPerAuthorizationModel) and the maximum model size in bytes are server configuration, not part of the model.
• Inline conditions. The experimental $expression condition (OpenFGA 1.21.0, "Dynamic Conditions") is not recognized. A form or tuple that names it needs a model condition of that name, as the abstractions' contract requires.
• Schema 1.0 and defaults. A model must state 1.1 or 1.2. WriteAuthorizationModel fills in 1.1 for an empty schema version; this package treats an empty version as unsupported.
• Lints of the DSL tooling. openfga/language also reports duplicate type restrictions ([user, user]), repeated rewrite operands (a or a) and unused conditions, and its identifier rules forbid * in type and relation names. The OpenFGA server does not enforce these, so neither does this package.
• Store state. Whether a tuple already exists, and limits on writes per request, depend on the store, not on the model.
• Malformed UTF-16. OpenFGA works on valid UTF-8. A .NET string with an unpaired surrogate has no UTF-8 form, and its code points are counted as replacement characters.

Design Principles

• IBool results — every condition is an IBool, keeping results composable within the Pure type system.
• Lazy evaluation — conditions are evaluated only when .BoolValue is accessed.
• False for non-conforming input — an invalid name, an inconsistent model or a non-conforming tuple evaluates to false. The one exception: an implementation of IRewrite, ISubject or ISubjectForm that is none of the known variants throws ArgumentException.
• AOT-compatible — no reflection; fully compatible with Native AOT compilation.

Dependencies

• Pure.Authorization.OpenFGA.Model.Abstractions 0.1.0-preview.0.1.0 — OpenFGA authorization model domain interfaces
• Pure.Primitives.Bool.Operations 0.5.1 — And, Or, Not
• Pure.Primitives.String.Operations 1.7.0 — string equality and character conditions
• Pure.Primitives.Number.Operations 1.5.0 — length comparisons
• Pure.Primitives.Char.Operations 0.4.0 — control character detection