Add support for Go analysis framework and SSA code representation

analyzer.go

@@ -31,6 +31,9 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/securego/gosec/v2/analyzers"
+	"golang.org/x/tools/go/analysis"
+	"golang.org/x/tools/go/analysis/passes/buildssa"
 	"golang.org/x/tools/go/packages"
 )
 
@@ -42,7 +45,10 @@ const LoadMode = packages.NeedName |
 	packages.NeedTypes |
 	packages.NeedTypesSizes |
 	packages.NeedTypesInfo |
-	packages.NeedSyntax
+	packages.NeedSyntax |
+	packages.NeedModule |
+	packages.NeedEmbedFiles |
+	packages.NeedEmbedPatterns
 
 const externalSuppressionJustification = "Globally suppressed."
 
@@ -60,8 +66,8 @@ type Context struct {
 	Pkg          *types.Package
 	PkgFiles     []*ast.File
 	Root         *ast.File
-	Config       Config
 	Imports      *ImportTracker
+	Config       Config
 	Ignores      []map[string][]SuppressionInfo
 	PassedValues map[string]interface{}
 }
@@ -90,6 +96,7 @@ type Analyzer struct {
 	showIgnored       bool
 	trackSuppressions bool
 	concurrency       int
+	analyzerList      []*analysis.Analyzer
 }
 
 // SuppressionInfo object is to record the kind and the justification that used
@@ -126,6 +133,7 @@ func NewAnalyzer(conf Config, tests bool, excludeGenerated bool, trackSuppressio
 		concurrency:       concurrency,
 		excludeGenerated:  excludeGenerated,
 		trackSuppressions: trackSuppressions,
+		analyzerList:      analyzers.BuildDefaultAnalyzers(),
 	}
 }
 
@@ -216,7 +224,10 @@ func (gosec *Analyzer) Process(buildTags []string, packagePaths ...string) error
 					wg.Wait() // wait for the goroutines to stop
 					return fmt.Errorf("parsing errors in pkg %q: %w", pkg.Name, err)
 				}
-				gosec.Check(pkg)
+				gosec.CheckRules(pkg)
+				if on, err := gosec.config.IsGlobalEnabled(SSA); err == nil && on {
+					gosec.CheckAnalyzers(pkg)
+				}
 			}
 		}
 	}
@@ -267,8 +278,8 @@ func (gosec *Analyzer) load(pkgPath string, conf *packages.Config) ([]*packages.
 	return pkgs, nil
 }
 
-// Check runs analysis on the given package
-func (gosec *Analyzer) Check(pkg *packages.Package) {
+// CheckRules runs analysis on the given package
+func (gosec *Analyzer) CheckRules(pkg *packages.Package) {
 	gosec.logger.Println("Checking package:", pkg.Name)
 	for _, file := range pkg.Syntax {
 		fp := pkg.Fset.File(file.Pos())
@@ -303,6 +314,70 @@ func (gosec *Analyzer) Check(pkg *packages.Package) {
 	}
 }
 
+// CheckAnalyzers runs analyzers on a given package
+func (gosec *Analyzer) CheckAnalyzers(pkg *packages.Package) {
+	ssaPass := &analysis.Pass{
+		Analyzer:          buildssa.Analyzer,
+		Fset:              pkg.Fset,
+		Files:             pkg.Syntax,
+		OtherFiles:        pkg.OtherFiles,
+		IgnoredFiles:      pkg.IgnoredFiles,
+		Pkg:               pkg.Types,
+		TypesInfo:         pkg.TypesInfo,
+		TypesSizes:        pkg.TypesSizes,
+		ResultOf:          nil,
+		Report:            nil,
+		ImportObjectFact:  nil,
+		ExportObjectFact:  nil,
+		ImportPackageFact: nil,
+		ExportPackageFact: nil,
+		AllObjectFacts:    nil,
+		AllPackageFacts:   nil,
+	}
+	ssaResult, err := ssaPass.Analyzer.Run(ssaPass)
+	if err != nil {
+		gosec.logger.Printf("Error running SSA analyser on package %q: %s", pkg.Name, err)
+		return
+	}
+	resultMap := map[*analysis.Analyzer]interface{}{
+		buildssa.Analyzer: &analyzers.SSAAnalyzerResult{
+			Config: gosec.Config(),
+			Logger: gosec.logger,
+			SSA:    ssaResult.(*buildssa.SSA),
+		},
+	}
+	for _, analyzer := range gosec.analyzerList {
+		pass := &analysis.Pass{
+			Analyzer:          analyzer,
+			Fset:              pkg.Fset,
+			Files:             pkg.Syntax,
+			OtherFiles:        pkg.OtherFiles,
+			IgnoredFiles:      pkg.IgnoredFiles,
+			Pkg:               pkg.Types,
+			TypesInfo:         pkg.TypesInfo,
+			TypesSizes:        pkg.TypesSizes,
+			ResultOf:          resultMap,
+			Report:            func(d analysis.Diagnostic) {},
+			ImportObjectFact:  nil,
+			ExportObjectFact:  nil,
+			ImportPackageFact: nil,
+			ExportPackageFact: nil,
+			AllObjectFacts:    nil,
+			AllPackageFacts:   nil,
+		}
+		result, err := pass.Analyzer.Run(pass)
+		if err != nil {
+			gosec.logger.Printf("Error running analyzer %s: %s\n", analyzer.Name, err)
+			continue
+		}
+		if result != nil {
+			if issue, ok := result.(*analyzers.Issue); ok {
+				gosec.updateIssues(toGosecIssue(issue), false, []SuppressionInfo{})
+			}
+		}
+	}
+}
+
 func isGeneratedFile(file *ast.File) bool {
 	for _, comment := range file.Comments {
 		for _, row := range comment.List {
@@ -426,20 +501,37 @@ func (gosec *Analyzer) ignore(n ast.Node) map[string]SuppressionInfo {
 // Visit runs the gosec visitor logic over an AST created by parsing go code.
 // Rule methods added with AddRule will be invoked as necessary.
 func (gosec *Analyzer) Visit(n ast.Node) ast.Visitor {
-	// If we've reached the end of this branch, pop off the ignores stack.
+	ignores, ok := gosec.updateIgnoredRules(n)
+	if !ok {
+		return gosec
+	}
+
+	// Using ast.File instead of ast.ImportSpec, so that we can track all imports at once.
+	switch i := n.(type) {
+	case *ast.File:
+		gosec.context.Imports.TrackFile(i)
+	}
+
+	for _, rule := range gosec.ruleset.RegisteredFor(n) {
+		suppressions, ignored := gosec.updateSuppressions(rule.ID(), ignores)
+		issue, err := rule.Match(n, gosec.context)
+		if err != nil {
+			file, line := GetLocation(n, gosec.context)
+			file = path.Base(file)
+			gosec.logger.Printf("Rule error: %v => %s (%s:%d)\n", reflect.TypeOf(rule), err, file, line)
+		}
+		gosec.updateIssues(issue, ignored, suppressions)
+	}
+	return gosec
+}
+
+func (gosec *Analyzer) updateIgnoredRules(n ast.Node) (map[string][]SuppressionInfo, bool) {
 	if n == nil {
 		if len(gosec.context.Ignores) > 0 {
 			gosec.context.Ignores = gosec.context.Ignores[1:]
 		}
-		return gosec
+		return nil, false
 	}
-	switch i := n.(type) {
-	case *ast.File:
-		// Using ast.File instead of ast.ImportSpec, so that we can track
-		// all imports at once.
-		gosec.context.Imports.TrackFile(i)
-	}
-
 	// Get any new rule exclusions.
 	ignoredRules := gosec.ignore(n)
 
@@ -458,30 +550,30 @@ func (gosec *Analyzer) Visit(n ast.Node) ast.Visitor {
 	// Push the new set onto the stack.
 	gosec.context.Ignores = append([]map[string][]SuppressionInfo{ignores}, gosec.context.Ignores...)
 
-	for _, rule := range gosec.ruleset.RegisteredFor(n) {
+	return ignores, true
+}
+
+func (gosec *Analyzer) updateSuppressions(id string, ignores map[string][]SuppressionInfo) ([]SuppressionInfo, bool) {
 	// Check if all rules are ignored.
 	generalSuppressions, generalIgnored := ignores[aliasOfAllRules]
 	// Check if the specific rule is ignored
-		ruleSuppressions, ruleIgnored := ignores[rule.ID()]
+	ruleSuppressions, ruleIgnored := ignores[id]
 
 	ignored := generalIgnored || ruleIgnored
 	suppressions := append(generalSuppressions, ruleSuppressions...)
 
 	// Track external suppressions.
-		if gosec.ruleset.IsRuleSuppressed(rule.ID()) {
+	if gosec.ruleset.IsRuleSuppressed(id) {
 		ignored = true
 		suppressions = append(suppressions, SuppressionInfo{
 			Kind:          "external",
 			Justification: externalSuppressionJustification,
 		})
 	}
+	return suppressions, ignored
+}
 
-		issue, err := rule.Match(n, gosec.context)
-		if err != nil {
-			file, line := GetLocation(n, gosec.context)
-			file = path.Base(file)
-			gosec.logger.Printf("Rule error: %v => %s (%s:%d)\n", reflect.TypeOf(rule), err, file, line)
-		}
+func (gosec *Analyzer) updateIssues(issue *Issue, ignored bool, suppressions []SuppressionInfo) {
 	if issue != nil {
 		if gosec.showIgnored {
 			issue.NoSec = ignored
@@ -496,8 +588,18 @@ func (gosec *Analyzer) Visit(n ast.Node) ast.Visitor {
 			gosec.issues = append(gosec.issues, issue)
 		}
 	}
+}
+
+func toGosecIssue(issue *analyzers.Issue) *Issue {
+	return &Issue{
+		File:       issue.File,
+		Line:       issue.Line,
+		Col:        issue.Col,
+		RuleID:     issue.AnalyzerID,
+		What:       issue.What,
+		Confidence: Score(issue.Confidence),
+		Severity:   Score(issue.Severity),
 	}
-	return gosec
 }
 
 // Report returns the current issues discovered and the metrics about the scan

analyzers/ssrf.go

@@ -0,0 +1,55 @@
+// (c) Copyright gosec's authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package analyzers
+
+import (
+	"golang.org/x/tools/go/analysis"
+	"golang.org/x/tools/go/analysis/passes/buildssa"
+	"golang.org/x/tools/go/ssa"
+)
+
+func newSSRFAnalyzer(id string, description string) *analysis.Analyzer {
+	return &analysis.Analyzer{
+		Name:     id,
+		Doc:      description,
+		Run:      runSSRF,
+		Requires: []*analysis.Analyzer{buildssa.Analyzer},
+	}
+}
+
+func runSSRF(pass *analysis.Pass) (interface{}, error) {
+	ssaResult, err := getSSAResult(pass)
+	if err != nil {
+		return nil, err
+	}
+	// TODO: implement the analysis
+	for _, fn := range ssaResult.SSA.SrcFuncs {
+		for _, block := range fn.DomPreorder() {
+			for _, instr := range block.Instrs {
+				switch instr := instr.(type) {
+				case *ssa.Call:
+					callee := instr.Call.StaticCallee()
+					if callee != nil {
+						ssaResult.Logger.Printf("callee: %s\n", callee)
+						return newIssue(pass.Analyzer.Name,
+							"not implemeted",
+							pass.Fset, instr.Call.Pos(), Low, High), nil
+					}
+				}
+			}
+		}
+	}
+	return nil, nil
+}

analyzers/util.go

@@ -0,0 +1,95 @@
+// (c) Copyright gosec's authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package analyzers
+
+import (
+	"fmt"
+	"go/token"
+	"log"
+	"strconv"
+
+	"golang.org/x/tools/go/analysis"
+	"golang.org/x/tools/go/analysis/passes/buildssa"
+)
+
+// SSAAnalyzerResult contains various information returned by the
+// SSA analysis along with some configuraion
+type SSAAnalyzerResult struct {
+	Config map[string]interface{}
+	Logger *log.Logger
+	SSA    *buildssa.SSA
+}
+
+// Score type used by severity and confidence values
+// TODO: remove this duplicated type
+type Score int
+
+const (
+	// Low severity or confidence
+	Low Score = iota
+	// Medium severity or confidence
+	Medium
+	// High severity or confidence
+	High
+)
+
+// Issue is returned by a gosec rule if it discovers an issue with the scanned code.
+// TODO: remove this duplicated type
+type Issue struct {
+	Severity   Score  `json:"severity"`    // issue severity (how problematic it is)
+	Confidence Score  `json:"confidence"`  // issue confidence (how sure we are we found it)
+	AnalyzerID string `json:"analyzer_id"` // Human readable explanation
+	What       string `json:"details"`     // Human readable explanation
+	File       string `json:"file"`        // File name we found it in
+	Code       string `json:"code"`        // Impacted code line
+	Line       string `json:"line"`        // Line number in file
+	Col        string `json:"column"`      // Column number in line
+}
+
+// BuildDefaultAnalyzers returns the default list of analyzers
+func BuildDefaultAnalyzers() []*analysis.Analyzer {
+	return []*analysis.Analyzer{
+		newSSRFAnalyzer("G107", "URL provided to HTTP request as taint input"),
+	}
+}
+
+// getSSAResult retrives the SSA result from analysis pass
+func getSSAResult(pass *analysis.Pass) (*SSAAnalyzerResult, error) {
+	result, ok := pass.ResultOf[buildssa.Analyzer]
+	if !ok {
+		return nil, fmt.Errorf("no SSA result found in the analysis pass")
+	}
+	ssaResult, ok := result.(*SSAAnalyzerResult)
+	if !ok {
+		return nil, fmt.Errorf("the analysis pass result is not of type SSA")
+	}
+	return ssaResult, nil
+}
+
+func newIssue(analyzerID string, desc string, fileSet *token.FileSet, pos token.Pos, severity Score, confidence Score) *Issue {
+	file := fileSet.File(pos)
+	line := file.Line(pos)
+	col := file.Position(pos).Column
+	// TODO: extract the code snippet and map the CWE
+	return &Issue{
+		File:       file.Name(),
+		Line:       strconv.Itoa(line),
+		Col:        strconv.Itoa(col),
+		Severity:   severity,
+		Confidence: confidence,
+		AnalyzerID: analyzerID,
+		What:       desc,
+	}
+}

config.go

@@ -29,6 +29,8 @@ const (
 	ExcludeRules GlobalOption = "exclude"
 	// IncludeRules global option for  should be load
 	IncludeRules GlobalOption = "include"
+	// SSA global option to enable go analysis framework with SSA support
+	SSA GlobalOption = "ssa"
 )
 
 // Config is used to provide configuration and customization to each of the rules.