Rule Type schema validation: change library and apply defaults (#4953)

* Rule Type schema validation: change library and apply defaults

This changes the underlying library to something that's actually
maintained: github.com/santhosh-tekuri/jsonschema/v6

It also adds the feature of applying defaults if they were defined in
the JSON schema.

Signed-off-by: Juan Antonio Osorio <[email protected]>

* Hook rule validation into engine so defaults are set.

Signed-off-by: Juan Antonio Osorio <[email protected]>

* Address comments

Signed-off-by: Juan Antonio Osorio <[email protected]>

---------

Signed-off-by: Juan Antonio Osorio <[email protected]>

go.mod

@@ -60,6 +60,7 @@ require (
 	github.com/puzpuzpuz/xsync/v3 v3.4.0
 	github.com/robfig/cron/v3 v3.0.1
 	github.com/rs/zerolog v1.33.0
+	github.com/santhosh-tekuri/jsonschema/v6 v6.0.1
 	github.com/signalfx/splunk-otel-go/instrumentation/database/sql/splunksql v1.22.0
 	github.com/signalfx/splunk-otel-go/instrumentation/github.com/lib/pq/splunkpq v1.22.0
 	github.com/sigstore/protobuf-specs v0.3.2
@@ -74,7 +75,6 @@ require (
 	github.com/styrainc/regal v0.29.1
 	github.com/thomaspoignant/go-feature-flag v1.38.0
 	github.com/xanzy/go-gitlab v0.113.0
-	github.com/xeipuuv/gojsonschema v1.2.0
 	github.com/yuin/goldmark v1.7.8
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.57.0
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.57.0

go.sum

@@ -948,6 +948,8 @@ github.com/sagikazarmark/slog-shim v0.1.0/go.mod h1:SrcSrq8aKtyuqEI1uvTDTK1arOWR
 github.com/sahilm/fuzzy v0.1.1 h1:ceu5RHF8DGgoi+/dR5PsECjCDH1BE3Fnmpo7aVXOdRA=
 github.com/sahilm/fuzzy v0.1.1/go.mod h1:VFvziUEIMCrT6A6tw2RFIXPXXmzXbOsSHF0DOI8ZK9Y=
 github.com/saintfish/chardet v0.0.0-20120816061221-3af4cd4741ca/go.mod h1:uugorj2VCxiV1x+LzaIdVa9b4S4qGAcH6cbhh4qVxOU=
+github.com/santhosh-tekuri/jsonschema/v6 v6.0.1 h1:PKK9DyHxif4LZo+uQSgXNqs0jj5+xZwwfKHgph2lxBw=
+github.com/santhosh-tekuri/jsonschema/v6 v6.0.1/go.mod h1:JXeL+ps8p7/KNMjDQk3TCwPpBy0wYklyWTfbkIzdIFU=
 github.com/sassoftware/relic v7.2.1+incompatible h1:Pwyh1F3I0r4clFJXkSI8bOyJINGqpgjJU3DYAZeI05A=
 github.com/sassoftware/relic v7.2.1+incompatible/go.mod h1:CWfAxv73/iLZ17rbyhIEq3K9hs5w6FpNMdUT//qR+zk=
 github.com/sassoftware/relic/v7 v7.6.2 h1:rS44Lbv9G9eXsukknS4mSjIAuuX+lMq/FnStgmZlUv4=
@@ -1074,7 +1076,6 @@ github.com/xanzy/go-gitlab v0.113.0 h1:v5O4R+YZbJGxKqa9iIZxjMyeKkMKBN8P6sZsNl+Yc
 github.com/xanzy/go-gitlab v0.113.0/go.mod h1:wKNKh3GkYDMOsGmnfuX+ITCmDuSDWFO0G+C4AygL9RY=
 github.com/xanzy/ssh-agent v0.3.3 h1:+/15pJfg/RsTxqYcX6fHqOXZwwMP+2VyYWJeWM2qQFM=
 github.com/xanzy/ssh-agent v0.3.3/go.mod h1:6dzNDKs0J9rVPHPhaGCukekBHKqfl+L3KghI1Bc68Uw=
-github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f/go.mod h1:N2zxlSyiKSe5eX1tZViRH5QA0qijqEDrYZiPEAiq3wU=
 github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb h1:zGWFAtiMcyryUHoUjUJX0/lt1H2+i2Ka2n+D3DImSNo=
 github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb/go.mod h1:N2zxlSyiKSe5eX1tZViRH5QA0qijqEDrYZiPEAiq3wU=
 github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 h1:EzJWgHovont7NscjpAxXsDA8S8BMYve8Y5+7cuRE7R0=

pkg/engine/v1/rtengine/engine.go

@@ -146,6 +146,22 @@ func (r *RuleTypeEngine) Eval(
 		}
 	}()
 
+	// The rule type has already been validated at creation time. However,
+	// re-validating it here is a good idea to ensure that the rule type
+	// has not been tampered with. Also, this sets the defaults for the
+	// rule definition.
+	if ruleDef != nil {
+		if err := r.ruleValidator.ValidateRuleDefAgainstSchema(ruleDef); err != nil {
+			return fmt.Errorf("rule definition validation failed: %w", err)
+		}
+	}
+
+	if ruleParams != nil {
+		if err := r.ruleValidator.ValidateParamsAgainstSchema(ruleParams); err != nil {
+			return fmt.Errorf("rule parameters validation failed: %w", err)
+		}
+	}
+
 	logger.Info().Msg("entity evaluation - ingest started")
 	// Try looking at the ingesting cache first
 	result, ok := r.ingestCache.Get(r.ingester, entity, ruleParams)

pkg/profiles/rule_validator.go

@@ -7,7 +7,8 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/xeipuuv/gojsonschema"
+	"github.com/santhosh-tekuri/jsonschema/v6"
+	"google.golang.org/protobuf/types/known/structpb"
 
 	minderv1 "github.com/mindersec/minder/pkg/api/protobuf/go/minder/v1"
 )
@@ -18,32 +19,32 @@ type RuleValidator struct {
 	ruleTypeName string
 
 	// schema is the schema that this rule type must conform to
-	schema *gojsonschema.Schema
+	schema *jsonschema.Schema
 	// paramSchema is the schema that the parameters for this rule type must conform to
-	paramSchema *gojsonschema.Schema
+	paramSchema *jsonschema.Schema
 }
 
 // NewRuleValidator creates a new rule validator
 func NewRuleValidator(rt *minderv1.RuleType) (*RuleValidator, error) {
-	// Load schemas
-	schemaLoader := gojsonschema.NewGoLoader(rt.Def.RuleSchema)
-	schema, err := gojsonschema.NewSchema(schemaLoader)
+	if rt.GetDef().GetRuleSchema() == nil {
+		return nil, fmt.Errorf("rule type %s does not have a rule schema", rt.Name)
+	}
+	// Create a new schema compiler
+	// Compile the main rule schema
+	mainSchema, err := compileSchemaFromPB(rt.GetDef().GetRuleSchema())
 	if err != nil {
 		return nil, fmt.Errorf("cannot create json schema: %w", err)
 	}
 
-	var paramSchema *gojsonschema.Schema
-	if rt.Def.ParamSchema != nil {
-		paramSchemaLoader := gojsonschema.NewGoLoader(rt.Def.ParamSchema)
-		paramSchema, err = gojsonschema.NewSchema(paramSchemaLoader)
-		if err != nil {
-			return nil, fmt.Errorf("cannot create json schema for params: %w", err)
-		}
+	// Compile the parameter schema if it exists
+	paramSchema, err := compileSchemaFromPB(rt.GetDef().GetParamSchema())
+	if err != nil {
+		return nil, fmt.Errorf("cannot create json schema for params: %w", err)
 	}
 
 	return &RuleValidator{
 		ruleTypeName: rt.Name,
-		schema:       schema,
+		schema:       mainSchema,
 		paramSchema:  paramSchema,
 	}, nil
 }
@@ -57,7 +58,7 @@ func (r *RuleValidator) ValidateRuleDefAgainstSchema(contextualProfile map[strin
 			Err:      err.Error(),
 		}
 	}
-
+	applyDefaults(r.schema, contextualProfile)
 	return nil
 }
 
@@ -67,36 +68,66 @@ func (r *RuleValidator) ValidateParamsAgainstSchema(params map[string]any) error
 	if r.paramSchema == nil {
 		return nil
 	}
-
 	if err := validateAgainstSchema(r.paramSchema, params); err != nil {
 		return &RuleValidationError{
 			RuleType: r.ruleTypeName,
 			Err:      err.Error(),
 		}
 	}
-
+	applyDefaults(r.paramSchema, params)
 	return nil
 }
 
-func validateAgainstSchema(schema *gojsonschema.Schema, obj map[string]any) error {
-	documentLoader := gojsonschema.NewGoLoader(obj)
-	result, err := schema.Validate(documentLoader)
-	if err != nil {
-		return fmt.Errorf("cannot validate json schema: %s", err)
+func compileSchemaFromPB(schemaData *structpb.Struct) (*jsonschema.Schema, error) {
+	if schemaData == nil {
+		return nil, nil
 	}
 
-	if !result.Valid() {
-		return buildValidationError(result.Errors())
+	return compileSchemaFromMap(schemaData.AsMap())
+}
+
+func compileSchemaFromMap(schemaData map[string]any) (*jsonschema.Schema, error) {
+	compiler := jsonschema.NewCompiler()
+	if err := compiler.AddResource("schema.json", schemaData); err != nil {
+		return nil, fmt.Errorf("invalid schema: %w", err)
 	}
+	return compiler.Compile("schema.json")
+}
 
+func validateAgainstSchema(schema *jsonschema.Schema, obj map[string]any) error {
+	if err := schema.Validate(obj); err != nil {
+		if verror, ok := err.(*jsonschema.ValidationError); ok {
+			return buildValidationError(verror.Causes)
+		}
+		return fmt.Errorf("invalid json schema: %s", err)
+	}
 	return nil
 }
 
-func buildValidationError(errs []gojsonschema.ResultError) error {
+func buildValidationError(errs []*jsonschema.ValidationError) error {
 	problems := make([]string, 0, len(errs))
 	for _, desc := range errs {
-		problems = append(problems, desc.String())
+		problems = append(problems, desc.Error())
 	}
-
 	return fmt.Errorf("invalid json schema: %s", strings.TrimSpace(strings.Join(problems, "\n")))
 }
+
+// applyDefaults recursively applies default values from the schema to the object.
+func applyDefaults(schema *jsonschema.Schema, obj map[string]any) {
+	for key, def := range schema.Properties {
+		// If the key does not exist in obj, apply the default value from the schema if present
+		if _, exists := obj[key]; !exists && def.Default != nil {
+			obj[key] = *def.Default
+		}
+
+		// If def has properties, apply defaults to the nested object
+		if def.Properties != nil {
+			o, ok := obj[key].(map[string]any)
+			if !ok {
+				// cannot apply defaults to non-object types
+				continue
+			}
+			applyDefaults(def, o)
+		}
+	}
+}

pkg/profiles/rule_validator_test.go

@@ -15,6 +15,77 @@ import (
 	"github.com/mindersec/minder/pkg/profiles"
 )
 
+func TestSetDefaultValuesOnValidation(t *testing.T) {
+	t.Parallel()
+
+	rtstr := `
+---
+version: v1
+release_phase: alpha
+type: rule-type
+name: foo
+display_name: Foo
+short_failure_message: Foo failed
+severity:
+  value: medium
+context:
+  provider: github
+description: Very important rule
+guidance: |
+  This is how you should do it.
+def:
+  in_entity: repository
+  rule_schema:
+    type: object
+    properties:
+      schedule_interval:
+        type: string
+        description: |
+          Sets the schedule interval in cron format for the workflow. Only applicable for remediation.
+      publish_results:
+        type: boolean
+        description: |
+          Publish the results of the analysis.
+        default: true
+      retention_days:
+        type: integer
+        description: |
+          Number of days to retain the SARIF file.
+        default: 5
+      sarif_file:
+        type: string
+        description: |
+          Name of the SARIF file.
+        default: "results.sarif"
+    required:
+      - schedule_interval
+      - publish_results
+`
+
+	rt := &minderv1.RuleType{}
+	require.NoError(t, minderv1.ParseResource(strings.NewReader(rtstr), rt), "failed to parse rule type")
+
+	rval, err := profiles.NewRuleValidator(rt)
+	require.NoError(t, err, "failed to create rule validator")
+
+	obj := map[string]any{
+		"schedule_interval": "0 0 * * *",
+		"publish_results":   false,
+		"retention_days":    10,
+	}
+
+	// Validation should pass
+	require.NoError(t, rval.ValidateRuleDefAgainstSchema(obj), "failed to validate rule definition")
+
+	// Value is left as is
+	require.Equal(t, "0 0 * * *", obj["schedule_interval"])
+	require.Equal(t, 10, obj["retention_days"])
+	require.Equal(t, false, obj["publish_results"])
+
+	// default is set
+	require.Equal(t, "results.sarif", obj["sarif_file"])
+}
+
 func TestExampleRulesAreValidatedCorrectly(t *testing.T) {
 	t.Parallel()