Add propagation string case functions and Array.join function (#98)

* String case operations

* Array join operator

* Fix lint

* Fix cpp-lint

* Fix cpp-lint

* Additional tests for Array.join

* Fix test denomination

* Fix arguments count

* Extract variables

* Proper initialization of newRanges for array join

* Remove unnecessary conditional

* Additional test for String case

* Fix lint

* Fix to avoid SegFault when checking new ranges

* Fix lint

binding.gyp

@@ -18,6 +18,8 @@
                 "./src/api/substring.cc",
                 "./src/api/replace.cc",
                 "./src/api/metrics.cc",
+                "./src/api/string_case.cc",
+                "./src/api/array_join.cc",
                 "./src/iast.cc"
             ],
             "include_dirs" : [

index.d.ts

@@ -41,5 +41,7 @@ declare module 'datadog-iast-taint-tracking' {
         substring(transactionId: string, subject: string, result: string, start: number, end: number): string;
         substr(transactionId: string, subject: string, result: string, start: number, length: number): string;
         replace(transactionId: string, result: string, thisArg: string, matcher: unknown, replacer: unknown): string;
+        stringCase(transactionId: string, result: string, thisArg: string): string;
+        arrayJoin(transactionId: string, result: string, thisArg: any[], separator?: any): string;
     }
 }

index.js

@@ -55,6 +55,12 @@ try {
     },
     substr (transaction, result) {
       return result
+    },
+    stringCase (transaction, result) {
+      return result
+    },
+    arrayJoin (transaction, result) {
+      return result
     }
   }
 }
@@ -75,7 +81,9 @@ const iastNativeMethods = {
   trimEnd: addon.trimEnd,
   slice: addon.slice,
   substring: addon.substring,
-  substr: addon.substr
+  substr: addon.substr,
+  stringCase: addon.stringCase,
+  arrayJoin: addon.arrayJoin
 }
 
 module.exports = iastNativeMethods

src/api/array_join.cc

@@ -0,0 +1,145 @@
+/**
+* Unless explicitly stated otherwise all files in this repository are licensed under the Apache-2.0 License.
+* This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2022 Datadog, Inc.
+**/
+#include <new>
+#include <vector>
+#include <memory>
+#include <string>
+
+#include "array_join.h"
+#include "../tainted/range.h"
+#include "../tainted/string_resource.h"
+#include "../tainted/transaction.h"
+#include "../iast.h"
+
+using v8::FunctionCallbackInfo;
+using v8::Value;
+using v8::Local;
+using v8::Isolate;
+using v8::Object;
+using v8::String;
+
+using iast::tainted::Range;
+
+namespace iast {
+namespace api {
+
+const int DEFAULT_JOIN_SEPARATOR_LENGTH = 1;
+
+void copyRangesWithOffset(Transaction* transaction,
+        SharedRanges* origRanges,
+        SharedRanges** destRanges,
+        int offset) {
+    if (origRanges != nullptr) {
+        auto end = origRanges->end();
+        for (auto it = origRanges->begin(); it != end; it++) {
+            auto origRange = *it;
+            auto newRange = transaction->GetRange(
+                origRange->start + offset,
+                origRange->end + offset,
+                origRange->inputInfo,
+                origRange->secureMarks);
+
+            if (newRange != nullptr) {
+                if (*destRanges == nullptr) {
+                    *destRanges = transaction->GetSharedVectorRange();
+                }
+                (*destRanges)->PushBack(newRange);
+            } else {
+                break;
+            }
+        }
+    }
+}
+
+SharedRanges* getJoinResultRanges(Isolate* isolate,
+        Transaction* transaction, v8::Array* arr,
+        SharedRanges* separatorRanges,
+        int separatorLength) {
+    auto length = arr->Length();
+    int offset = 0;
+    SharedRanges* newRanges = nullptr;
+    auto context = isolate->GetCurrentContext();
+    for (uint32_t i = 0; i < length; i++) {
+        if (i > 0) {
+            copyRangesWithOffset(transaction, separatorRanges, &newRanges, offset);
+            offset += separatorLength;
+        }
+        auto maybeItem = arr->Get(context, i);
+        if (!maybeItem.IsEmpty()) {
+            auto item = maybeItem.ToLocalChecked();
+            auto taintedItem = transaction->FindTaintedObject(utils::GetLocalPointer(item));
+            auto itemRanges = taintedItem ? taintedItem->getRanges() : nullptr;
+            copyRangesWithOffset(transaction, itemRanges, &newRanges, offset);
+            offset += utils::GetLength(isolate, item);
+        }
+    }
+
+    return newRanges;
+}
+
+void ArrayJoinOperator(const FunctionCallbackInfo<Value>& args) {
+    auto isolate = args.GetIsolate();
+
+    if (args.Length() < 3) {
+        isolate->ThrowException(v8::Exception::TypeError(
+                        v8::String::NewFromUtf8(isolate,
+                        "Wrong number of arguments",
+                        v8::NewStringType::kNormal).ToLocalChecked()));
+        return;
+    }
+
+    auto result = args[1];
+
+    if (!result->IsString()) {
+        args.GetReturnValue().Set(result);
+        return;
+    }
+
+    auto transaction = GetTransaction(utils::GetLocalPointer(args[0]));
+    if (transaction == nullptr) {
+        args.GetReturnValue().Set(result);
+        return;
+    }
+
+    auto thisArg = args[2];
+    if (thisArg->IsObject()) {
+        auto arrObj = v8::Object::Cast(*thisArg);
+        if (arrObj->IsArray()) {
+            try {
+                int separatorLength = DEFAULT_JOIN_SEPARATOR_LENGTH;
+                SharedRanges* separatorRanges = nullptr;
+                if (args.Length() > 3) {
+                    auto separatorArg = args[3];
+                    auto separatorValue = (*separatorArg);
+                    if (!separatorValue->IsUndefined()) {
+                        auto taintedSeparator = transaction->FindTaintedObject(utils::GetLocalPointer(separatorArg));
+                        separatorRanges = taintedSeparator ? taintedSeparator->getRanges() : nullptr;
+                        separatorLength = utils::GetCoercedLength(isolate, separatorArg);
+                    }
+                }
+                auto arr = v8::Array::Cast(arrObj);
+
+                auto newRanges = getJoinResultRanges(isolate, transaction, arr, separatorRanges, separatorLength);
+                if (newRanges != nullptr) {
+                    auto key = utils::GetLocalPointer(result);
+                    transaction->AddTainted(key, newRanges, result);
+                    args.GetReturnValue().Set(result);
+                    return;
+                }
+            } catch (const std::bad_alloc& err) {
+            } catch (const container::QueuedPoolBadAlloc& err) {
+            } catch (const container::PoolBadAlloc& err) {
+            }
+        }
+    }
+    args.GetReturnValue().Set(args[1]);
+}
+
+void ArrayJoinOperations::Init(Local<Object> exports) {
+    NODE_SET_METHOD(exports, "arrayJoin", ArrayJoinOperator);
+}
+}   // namespace api
+}   // namespace iast
+

src/api/array_join.h

@@ -0,0 +1,21 @@
+/**
+* Unless explicitly stated otherwise all files in this repository are licensed under the Apache-2.0 License.
+* This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2022 Datadog, Inc.
+**/
+#ifndef SRC_API_ARRAY_JOIN_H_
+#define SRC_API_ARRAY_JOIN_H_
+
+#include <node.h>
+namespace iast {
+namespace api {
+class ArrayJoinOperations {
+ public:
+    static void Init(v8::Local<v8::Object> exports);
+
+ private:
+    ArrayJoinOperations();
+    ~ArrayJoinOperations();
+};
+}   // namespace api
+}   // namespace iast
+#endif  // SRC_API_ARRAY_JOIN_H_

src/api/string_case.cc

@@ -0,0 +1,90 @@
+/**
+* Unless explicitly stated otherwise all files in this repository are licensed under the Apache-2.0 License.
+* This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2022 Datadog, Inc.
+**/
+#include <new>
+#include <vector>
+#include <memory>
+#include <string>
+
+#include "string_case.h"
+#include "../tainted/range.h"
+#include "../tainted/string_resource.h"
+#include "../tainted/transaction.h"
+#include "../iast.h"
+
+#define TO_V8STRING(arg) (v8::Local<v8::String>::Cast(arg))
+
+using v8::FunctionCallbackInfo;
+using v8::Value;
+using v8::Local;
+using v8::Isolate;
+using v8::Object;
+using v8::String;
+
+using iast::tainted::Range;
+
+namespace iast {
+namespace api {
+
+void StringCaseOperator(const FunctionCallbackInfo<Value>& args) {
+    auto isolate = args.GetIsolate();
+
+    if (args.Length() < 3) {
+        isolate->ThrowException(v8::Exception::TypeError(
+                        v8::String::NewFromUtf8(isolate,
+                        "Wrong number of arguments",
+                        v8::NewStringType::kNormal).ToLocalChecked()));
+        return;
+    }
+    if (!args[1]->IsString()) {
+        args.GetReturnValue().Set(args[1]);
+        return;
+    }
+
+    auto transaction = GetTransaction(utils::GetLocalPointer(args[0]));
+    if (transaction == nullptr) {
+        args.GetReturnValue().Set(args[1]);
+        return;
+    }
+
+    if (args[1] == args[2]) {
+        args.GetReturnValue().Set(args[1]);
+        return;
+    }
+
+    auto taintedObj = transaction->FindTaintedObject(utils::GetLocalPointer(args[2]));
+    if (!taintedObj) {
+        args.GetReturnValue().Set(args[1]);
+        return;
+    }
+
+    try {
+        auto ranges = taintedObj->getRanges();
+        if (ranges == nullptr) {
+            args.GetReturnValue().Set(args[1]);
+            return;
+        }
+
+        auto res = args[1];
+        int resultLength = TO_V8STRING(res)->Length();
+        if (resultLength == 1) {
+            res = tainted::NewExternalString(isolate, res);
+        }
+        auto key = utils::GetLocalPointer(res);
+        transaction->AddTainted(key, ranges, res);
+        args.GetReturnValue().Set(res);
+        return;
+    } catch (const std::bad_alloc& err) {
+    } catch (const container::QueuedPoolBadAlloc& err) {
+    } catch (const container::PoolBadAlloc& err) {
+    }
+    args.GetReturnValue().Set(args[1]);
+}
+
+void StringCaseOperations::Init(Local<Object> exports) {
+    NODE_SET_METHOD(exports, "stringCase", StringCaseOperator);
+}
+}   // namespace api
+}   // namespace iast
+

src/api/string_case.h

@@ -0,0 +1,21 @@
+/**
+* Unless explicitly stated otherwise all files in this repository are licensed under the Apache-2.0 License.
+* This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2022 Datadog, Inc.
+**/
+#ifndef SRC_API_STRING_CASE_H_
+#define SRC_API_STRING_CASE_H_
+
+#include <node.h>
+namespace iast {
+namespace api {
+class StringCaseOperations {
+ public:
+    static void Init(v8::Local<v8::Object> exports);
+
+ private:
+    StringCaseOperations();
+    ~StringCaseOperations();
+};
+}   // namespace api
+}   // namespace iast
+#endif  // SRC_API_STRING_CASE_H_

src/iast.cc

@@ -17,6 +17,8 @@
 #include "api/substring.h"
 #include "api/replace.h"
 #include "api/metrics.h"
+#include "api/string_case.h"
+#include "api/array_join.h"
 
 using transactionManager = iast::container::Singleton<iast::TransactionManager<iast::tainted::Transaction,
       iast::tainted::transaction_key_t>>;
@@ -50,6 +52,8 @@ void Init(v8::Local<v8::Object> exports) {
     api::SliceOperations::Init(exports);
     api::Substring::Init(exports);
     api::ReplaceOperations::Init(exports);
+    api::StringCaseOperations::Init(exports);
+    api::ArrayJoinOperations::Init(exports);
     api::Metrics::Init(exports);
     exports->GetIsolate()->AddGCEpilogueCallback(iast::gc::OnScavenge, v8::GCType::kGCTypeScavenge);
     exports->GetIsolate()->AddGCEpilogueCallback(iast::gc::OnMarkSweepCompact, v8::GCType::kGCTypeMarkSweepCompact);