feat(misconf): support for policy and bucket grants

Signed-off-by: nikpivkin <nikita.pivkin@smartforce.io>
aquasecurity · simar7 · Aug 6, 2024 · Jul 31, 2024 · Aug 1, 2024 · Aug 1, 2024
commit 53d2c1429e7b6c0aab260ecdd8b6c3a3ae57ebfc
@@ -7,7 +7,9 @@ import (
 	"strings"
 
 	s3types "github.com/aws/aws-sdk-go-v2/service/s3/types"
+	"github.com/liamg/iamgo"
 
+	"github.com/aquasecurity/trivy/pkg/iac/providers/aws/iam"
 	"github.com/aquasecurity/trivy/pkg/iac/providers/aws/s3"
 	"github.com/aquasecurity/trivy/pkg/iac/scanners/cloudformation/parser"
 	iacTypes "github.com/aquasecurity/trivy/pkg/iac/types"
@@ -37,6 +39,7 @@ func getBuckets(cfFile parser.FileContext) []s3.Bucket {
 			Website:                       getWebsite(r),
 			BucketLocation:                iacTypes.String("", r.Metadata()),
 			Objects:                       nil,
+			BucketPolicies:                getBucketPolicies(cfFile, r),
 		}
 
 		buckets = append(buckets, s3b)
@@ -156,3 +159,35 @@ func getWebsite(r *parser.Resource) *s3.Website {
 		}
 	}
 }
+
+func getBucketPolicies(fctx parser.FileContext, r *parser.Resource) []iam.Policy {
+
+	var policies []iam.Policy
+	for _, bucketPolicy := range fctx.GetResourcesByType("AWS::S3::BucketPolicy") {
+		bucket := bucketPolicy.GetStringProperty("Bucket")
+		if bucket.NotEqualTo(r.GetStringProperty("BucketName").Value()) && bucket.NotEqualTo(r.ID()) {
+			continue
+		}
+
+		doc := bucketPolicy.GetProperty("PolicyDocument")
+		if doc.IsNil() {
+			continue
+		}
+
+		parsed, err := iamgo.Parse(doc.GetJsonBytes())
+		if err != nil {
+			continue
+		}
+		policies = append(policies, iam.Policy{
+			Metadata: doc.Metadata(),
+			Name:     iacTypes.StringDefault("", doc.Metadata()),
+			Document: iam.Document{
+				Metadata: doc.Metadata(),
+				Parsed:   *parsed,
+			},
+			Builtin: iacTypes.Bool(false, doc.Metadata()),
+		})
+	}
+
+	return policies
+}
@@ -3,7 +3,10 @@ package s3
 import (
 	"testing"
 
+	"github.com/liamg/iamgo"
+
 	"github.com/aquasecurity/trivy/pkg/iac/adapters/cloudformation/testutil"
+	"github.com/aquasecurity/trivy/pkg/iac/providers/aws/iam"
 	"github.com/aquasecurity/trivy/pkg/iac/providers/aws/s3"
 	"github.com/aquasecurity/trivy/pkg/iac/types"
 )
@@ -57,6 +60,19 @@ Resources:
         Status: Enabled
       WebsiteConfiguration:
         IndexDocument: index.html
+  SampleBucketPolicy:
+    Type: AWS::S3::BucketPolicy
+    Properties:
+      Bucket: !Ref Bucket
+      PolicyDocument:
+        Version: 2012-10-17
+        Statement:
+          - Action:
+              - 's3:GetObject'
+            Effect: Allow
+            Resource: !Join
+              - 'arn:aws:s3:::testbucket/*'
+            Principal: '*'
 `,
 			expected: s3.S3{
 				Buckets: []s3.Bucket{
@@ -91,6 +107,23 @@ Resources:
 							Enabled: types.BoolTest(true),
 						},
 						Website: &s3.Website{},
+						BucketPolicies: []iam.Policy{
+							{
+								Document: iam.Document{
+									Parsed: iamgo.NewPolicyBuilder().
+										WithStatement(
+											iamgo.NewStatementBuilder().
+												WithActions([]string{"s3:GetObject"}).
+												WithAllPrincipals(true).
+												WithEffect("Allow").
+												WithResources([]string{"arn:aws:s3:::testbucket/*"}).
+												Build(),
+										).
+										WithVersion("2012-10-17T00:00:00Z").
+										Build(),
+								},
+							},
+						},
 					},
 				},
 			},

@@ -149,6 +149,15 @@ func Test_Adapt(t *testing.T) {
 			 resource "aws_s3_bucket_acl" "example" {
 				bucket = aws_s3_bucket.example.id
 				acl    = "private"
+				access_control_policy {
+					grant {
+						grantee {
+							type = "Group"
+							uri  = "http://acs.amazonaws.com/groups/s3/LogDelivery"
+						}
+						permission = "READ_ACP"
+					}
+				}
 			  }
 
 			  resource "aws_s3_bucket_server_side_encryption_configuration" "example" {
@@ -250,6 +259,51 @@ func Test_Adapt(t *testing.T) {
 							TargetBucket: iacTypes.String("aws_s3_bucket.example", iacTypes.NewTestMetadata()),
 						},
 						ACL: iacTypes.String("private", iacTypes.NewTestMetadata()),
+						Grants: []s3.Grant{
+							{
+								Metadata: iacTypes.NewTestMetadata(),
+								Grantee: s3.Grantee{
+									Type: iacTypes.StringTest("Group"),
+									URI:  iacTypes.StringTest("http://acs.amazonaws.com/groups/s3/LogDelivery"),
+								},
+								Permissions: iacTypes.StringValueList{
+									iacTypes.StringTest("READ_ACP"),
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "bucket with grants",
+			terraform: `
+resource "aws_s3_bucket" "this" {
+  bucket = "test"
+
+  grant {
+	type = "Group"
+	uri  = "http://acs.amazonaws.com/groups/s3/LogDelivery"
+	permissions = ["FULL_CONTROL"]
+  }
+}
+`,
+			expected: s3.S3{
+				Buckets: []s3.Bucket{
+					{
+						Name: iacTypes.StringTest("test"),
+						ACL:  iacTypes.StringTest("private"),
+						Grants: []s3.Grant{
+							{
+								Grantee: s3.Grantee{
+									Type: iacTypes.StringTest("Group"),
+									URI:  iacTypes.StringTest("http://acs.amazonaws.com/groups/s3/LogDelivery"),
+								},
+								Permissions: iacTypes.StringValueList{
+									iacTypes.StringTest("FULL_CONTROL"),
+								},
+							},
+						},
 					},
 				},
 			},

@@ -26,6 +26,7 @@ func (a *adapter) adaptBuckets() []s3.Bucket {
 			Versioning:                    getVersioning(block, a),
 			Logging:                       getLogging(block, a),
 			ACL:                           getBucketAcl(block, a),
+			Grants:                        getGrants(block, a),
 			AccelerateConfigurationStatus: getAccelerateStatus(block, a),
 			BucketLocation:                block.GetAttribute("region").AsStringValueOrDefault("", block),
 			LifecycleConfiguration:        getLifecycle(block, a),
@@ -193,6 +194,55 @@ func getBucketAcl(block *terraform.Block, a *adapter) iacTypes.StringValue {
 	return iacTypes.StringDefault("private", block.GetMetadata())
 }
 
+func getGrants(block *terraform.Block, a *adapter) []s3.Grant {
+	if val, ok := applyForBucketRelatedResource(a, block, "aws_s3_bucket_acl", func(resource *terraform.Block) []s3.Grant {
+		var grants []s3.Grant
+
+		if acessControlPolicy := resource.GetBlock("access_control_policy"); acessControlPolicy.IsNotNil() {
+			for _, grantBlock := range acessControlPolicy.GetBlocks("grant") {
+				grant := s3.Grant{
+					Metadata: grantBlock.GetMetadata(),
+					Permissions: iacTypes.StringValueList{
+						grantBlock.GetAttribute("permission").AsStringValueOrDefault("", grantBlock),
+					},
+				}
+
+				if granteeBlock := grantBlock.GetBlock("grantee"); granteeBlock.IsNotNil() {
+					grant.Grantee = s3.Grantee{
+						Metadata: granteeBlock.GetMetadata(),
+						Type:     granteeBlock.GetAttribute("type").AsStringValueOrDefault("", granteeBlock),
+						URI:      granteeBlock.GetAttribute("uri").AsStringValueOrDefault("", granteeBlock),
+					}
+				}
+
+				grants = append(grants, grant)
+			}
+		}
+
+		return grants
+
+	}); ok {
+		return val
+	}
+
+	var grants []s3.Grant
+	for _, grantBlock := range block.GetBlocks("grant") {
+		grant := s3.Grant{
+			Metadata:    grantBlock.GetMetadata(),
+			Permissions: grantBlock.GetAttribute("permissions").AsStringValueSliceOrEmpty(),
+			Grantee: s3.Grantee{
+				Metadata: grantBlock.GetMetadata(),
+				Type:     grantBlock.GetAttribute("type").AsStringValueOrDefault("", grantBlock),
+				URI:      grantBlock.GetAttribute("uri").AsStringValueOrDefault("", grantBlock),
+			},
+		}
+
+		grants = append(grants, grant)
+	}
+
+	return grants
+}
+
 func isEncrypted(sseConfgihuration *terraform.Block) iacTypes.BoolValue {
 	return terraform.MapNestedAttribute(
 		sseConfgihuration,

@@ -14,6 +14,7 @@ type Bucket struct {
 	Versioning                    Versioning
 	Logging                       Logging
 	ACL                           iacTypes.StringValue
+	Grants                        []Grant
 	BucketLocation                iacTypes.StringValue
 	AccelerateConfigurationStatus iacTypes.StringValue
 	LifecycleConfiguration        []Rules
@@ -65,3 +66,15 @@ type Contents struct {
 type Website struct {
 	Metadata iacTypes.Metadata
 }
+
+type Grant struct {
+	Metadata    iacTypes.Metadata
+	Grantee     Grantee
+	Permissions iacTypes.StringValueList
+}
+
+type Grantee struct {
+	Metadata iacTypes.Metadata
+	URI      iacTypes.StringValue
+	Type     iacTypes.StringValue
+}