Merge pull request #172 from sarika-subram/main

Fix #167

services/s3/drivers/S3Bucket.py

@@ -17,48 +17,67 @@ def __init__(self, bucket, s3Client):
 
         self.init()
 
-    def policyAllowsPublicRead (self, policy_document):
-        # Check if the policy allows public read access
-        # Check if the policy allows public read access
-        response = None
-        policy_allows_public_read = False
-        if policy_document:
-            iam = boto3.client('iam')
-            response = iam.simulate_principal_policy(
-                PolicySourceArn=f"arn:aws:s3:::{self.bucket}",
-                PolicyInputList=[policy_document],
-                ActionNames=['s3:GetObject', 's3:ListBucket'],
-                ResourceArns=[f"arn:aws:s3:::{self.bucket}", f"arn:aws:s3:::{self.bucket}/*"],
-                PermissionsBoundarySet=[],
-                ContextEntries=[],
-                ResourceHandlingOption='SINGLE_SERVICE_MULTI_RESOURCE'
-            )
-
-        if response and response['EvaluationResults'][0]['EvalDecision'] == 'allowed':
-            policy_allows_public_read = True
-        return policy_allows_public_read
-
-    def policyAllowsPublicWrite (self, policy_document):
-        # Check if the policy allows public read access
-        # Check if the policy allows public read access
-        response = None
-        policy_allows_public_write = True
-        if policy_document:
-            iam = boto3.client('iam')
-            response = iam.simulate_principal_policy(
-                PolicySourceArn=f"arn:aws:s3:::{self.bucket}",
-                PolicyInputList=[policy_document],
-                ActionNames=['s3:PutObject'],
-                ResourceArns=[f"arn:aws:s3:::{self.bucket}", f"arn:aws:s3:::{self.bucket}/*"],
-                PermissionsBoundarySet=[],
-                ContextEntries=[],
-                ResourceHandlingOption='SINGLE_SERVICE_MULTI_RESOURCE'
-            )
-
-        if response and response['EvaluationResults'][0]['EvalDecision'] == 'allowed':
-            policy_allows_public_write = True
-        return policy_allows_public_write
+    def policyAllowsPublicRead(self, policy_document):
+        """
+        Check if the policy allows public read access
+        
+        Args:
+            policy_document (str): The bucket policy as a string
+        
+        Returns:
+            bool: True if policy allows public read access, False otherwise
+        """
+        if not policy_document:
+            return False
+
+        try:
+            policy = json.loads(policy_document)
+
+            # Check for public read in policy
+            for statement in policy['Statement']:
+                principal = statement.get('Principal', {})
+                if (principal == '*' or principal.get('AWS') == '*') and \
+                   statement['Effect'] == 'Allow' and \
+                   any(action in ['s3:GetObject', 's3:GetObjectVersion', 's3:ListBucket'] 
+                       for action in (statement.get('Action', []) if isinstance(statement.get('Action', []), list) 
+                                    else [statement.get('Action', [])])):
+                    return True
+
+            return False
+
+        except (json.JSONDecodeError, KeyError):
+            return False
 
+    def policyAllowsPublicWrite(self, policy_document):
+        """
+        Check if the policy allows public write access
+        
+        Args:
+            policy_document (str): The bucket policy as a string
+        
+        Returns:
+            bool: True if policy allows public write access, False otherwise
+        """
+        if not policy_document:
+            return False
+
+        try:
+            policy = json.loads(policy_document)
+
+            # Check for public write in policy
+            for statement in policy['Statement']:
+                principal = statement.get('Principal', {})
+                if (principal == '*' or principal.get('AWS') == '*') and \
+                   statement['Effect'] == 'Allow' and \
+                   any(action in ['s3:PutObject', 's3:DeleteObject'] 
+                       for action in (statement.get('Action', []) if isinstance(statement.get('Action', []), list) 
+                                    else [statement.get('Action', [])])):
+                    return True
+
+            return False
+
+        except (json.JSONDecodeError, KeyError):
+            return False
 
     def getBucketPolicy(self):
         try:
@@ -133,12 +152,10 @@ def _checkAccess(self):
         except botocore.exceptions.ClientError as e:
             if e.response['Error']['Code'] == 'NoSuchAcl':
                 return None
-
 
         # check if S3 bucket has prohibited public reads 
         policy = self.getBucketPolicy()    
 
-
         if (public_policy_restricted or not self.policyAllowsPublicRead(policy)) and (public_acl_restricted or not self.aclAllowsPublicRead(bucket_acl)):
             self.results['PublicReadAccessBlock'] = [1, 'Prohibited'] 
         else:
@@ -150,7 +167,6 @@ def _checkAccess(self):
         else:
             self.results['PublicWriteAccessBlock'] = [-1, 'NotProhibited'] 
 
-
     def _checkMfaDeleteAndVersioning(self):
         self.results['MFADelete'] = [-1, 'Off']
         self.results['BucketVersioning'] = [-1, 'Off']
@@ -197,8 +213,6 @@ def _checkBucketReplication(self):
             if e.response['Error']['Code'] == 'ReplicationConfigurationNotFoundError':
                 self.results['BucketReplication'] = [-1, 'Off']
 
-
-
     def _checkLifecycle(self):
         self.results['BucketLifecycle'] = [1, 'On']
         try: