Feature/116 add if condition executor (#138)

docs/content/en/docs/core-components/executer.md

@@ -202,7 +202,11 @@ The result of the step comparison will be returned to the decomposer. A result c
 ### While condition executor 
 The if-condition executor will process a cacao while-condition step and determine it's output. 
 
-The result of the step comparison will be returned to the decomposer. A result can be either a next step id and/or error status. 
+The result of the step comparison will be returned to the decomposer. A result can be either a next step id and/or error status. Only STIX comparison expressions are implemented at this time. 
+
+{{% alert title="Warning" color="warning" %}}
+Note only [Comparison Expression](http://docs.oasis-open.org/cti/stix/v2.0/cs01/part5-stix-patterning/stix-v2.0-cs01-part5-stix-patterning.html#_Toc496717749) are implemented for all CACAO variable types.
+{{% /alert %}}
 
 ### Parallel step executor
 The parallel executor will execute the parallel step. This wil be done in sequence to simplify implementation. As parallel steps must not be depended on each other sequential execution is possible. Later this will be changed. 

internal/controller/controller.go

@@ -15,13 +15,15 @@ import (
 	"soarca/internal/capability/ssh"
 	"soarca/internal/decomposer"
 	"soarca/internal/executors/action"
+	"soarca/internal/executors/condition"
 	"soarca/internal/executors/playbook_action"
 	"soarca/internal/fin/protocol"
 	"soarca/internal/guid"
 	"soarca/internal/reporter"
 	"soarca/logger"
 	"soarca/utils"
 	httpUtil "soarca/utils/http"
+	"soarca/utils/stix/expression/comparison"
 
 	downstreamReporter "soarca/internal/reporter/downstream_reporter"
 
@@ -78,8 +80,14 @@ func (controller *Controller) NewDecomposer() decomposer.IDecomposer {
 
 	actionExecutor := action.New(capabilities, reporter)
 	playbookActionExecutor := playbook_action.New(controller, controller, reporter)
+	stixComparison := comparison.New()
+	conditionExecutor := condition.New(stixComparison, reporter)
 	guid := new(guid.Guid)
-	decompose := decomposer.New(actionExecutor, playbookActionExecutor, guid, reporter)
+	decompose := decomposer.New(actionExecutor,
+		playbookActionExecutor,
+		conditionExecutor,
+		guid,
+		reporter)
 	return decompose
 }
 

internal/decomposer/decomposer.go

@@ -7,6 +7,7 @@ import (
 
 	"soarca/internal/executors"
 	"soarca/internal/executors/action"
+	"soarca/internal/executors/condition"
 	"soarca/internal/guid"
 	"soarca/internal/reporter"
 	"soarca/logger"
@@ -39,19 +40,24 @@ func init() {
 
 func New(actionExecutor action.IExecuter,
 	playbookActionExecutor executors.IPlaybookExecuter,
-	guid guid.IGuid, reporter reporter.IWorkflowReporter) *Decomposer {
+	condition condition.IExecuter,
+	guid guid.IGuid,
+	reporter reporter.IWorkflowReporter) *Decomposer {
 
 	return &Decomposer{actionExecutor: actionExecutor,
 		playbookActionExecutor: playbookActionExecutor,
+		conditionExecutor:      condition,
 		guid:                   guid,
-		reporter:               reporter}
+		reporter:               reporter,
+	}
 }
 
 type Decomposer struct {
 	playbook               cacao.Playbook
 	details                ExecutionDetails
 	actionExecutor         action.IExecuter
 	playbookActionExecutor executors.IPlaybookExecuter
+	conditionExecutor      condition.IExecuter
 	guid                   guid.IGuid
 	reporter               reporter.IWorkflowReporter
 }
@@ -157,6 +163,15 @@ func (decomposer *Decomposer) ExecuteStep(step cacao.Step, scopeVariables cacao.
 		return decomposer.actionExecutor.Execute(metadata, actionMetadata)
 	case cacao.StepTypePlaybookAction:
 		return decomposer.playbookActionExecutor.Execute(metadata, step, variables)
+	case cacao.StepTypeIfCondition:
+		stepId, branch, err := decomposer.conditionExecutor.Execute(metadata, step, variables)
+		if err != nil {
+			return cacao.NewVariables(), err
+		}
+		if branch {
+			return decomposer.ExecuteBranch(stepId, variables)
+		}
+		return variables, nil
 	default:
 		// NOTE: This currently silently handles unknown step types. Should we return an error instead?
 		return cacao.NewVariables(), nil

internal/executors/condition/condition.go

@@ -0,0 +1,76 @@
+package condition
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"soarca/internal/reporter"
+	"soarca/logger"
+	"soarca/models/cacao"
+	"soarca/models/execution"
+	"soarca/utils/stix/expression/comparison"
+)
+
+var component = reflect.TypeOf(Executor{}).PkgPath()
+var log *logger.Log
+
+func init() {
+	log = logger.Logger(component, logger.Info, "", logger.Json)
+}
+
+func New(comparison comparison.IComparison,
+	reporter reporter.IStepReporter) *Executor {
+	return &Executor{comparison: comparison,
+		reporter: reporter}
+}
+
+type IExecuter interface {
+	Execute(metadata execution.Metadata,
+		step cacao.Step, variables cacao.Variables) (string, bool, error)
+}
+
+type Executor struct {
+	comparison comparison.IComparison
+	reporter   reporter.IStepReporter
+}
+
+func (executor *Executor) Execute(meta execution.Metadata, step cacao.Step, variables cacao.Variables) (string, bool, error) {
+
+	if step.Type != cacao.StepTypeIfCondition {
+		err := errors.New("the provided step type is not compatible with this executor")
+		log.Error(err)
+		return step.OnFailure, false, err
+	}
+
+	executor.reporter.ReportStepStart(meta.ExecutionId, step, variables)
+
+	result, err := executor.comparison.Evaluate(step.Condition, variables)
+
+	// We are reporting early to not have double reporting
+	executor.reporter.ReportStepEnd(meta.ExecutionId,
+		step,
+		variables,
+		err)
+
+	if err != nil {
+		log.Error(err)
+		return "", false, err
+	}
+
+	log.Debug("the result was: ", fmt.Sprint(result))
+
+	if result {
+		if step.OnTrue != "" {
+			log.Trace("will return on true step ", step.OnTrue)
+			return step.OnTrue, true, nil
+		}
+	} else {
+		if step.OnFalse != "" {
+			log.Trace("will return on false step ", step.OnFalse)
+			return step.OnFalse, true, nil
+		}
+	}
+	log.Trace("will return on completion step ", step.OnCompletion)
+
+	return step.OnCompletion, false, nil
+}