Add DecodeWithContext method to Transform API layers.

Author: bpotchik

binaryninjaapi.h

@@ -8928,6 +8928,8 @@ namespace BinaryNinja {
 		size_t fixedLength;  // Variable length if zero
 	};
 
+	class TransformContext;
+
 	/*! Allows users to implement custom transformations.
 
 	    New transformations may be added at runtime, so an instance of a transform is created like
@@ -8970,6 +8972,7 @@ namespace BinaryNinja {
 		    void* ctxt, BNDataBuffer* input, BNDataBuffer* output, BNTransformParameter* params, size_t paramCount);
 		static bool EncodeCallback(
 		    void* ctxt, BNDataBuffer* input, BNDataBuffer* output, BNTransformParameter* params, size_t paramCount);
+		static bool DecodeWithContextCallback(void* ctxt, BNTransformContext* context, BNTransformParameter* params, size_t paramCount);
 		static bool CanDecodeCallback(void* ctxt, BNBinaryView* input);
 
 		static std::vector<TransformParameter> EncryptionKeyParameters(size_t fixedKeyLength = 0);
@@ -8987,6 +8990,7 @@ namespace BinaryNinja {
 		BNTransformType GetType() const;
 		BNTransformCapabilities GetCapabilities() const;
 		bool SupportsDetection() const;
+		bool SupportsContext() const;
 		std::string GetName() const;
 		std::string GetLongName() const;
 		std::string GetGroup() const;
@@ -8995,6 +8999,7 @@ namespace BinaryNinja {
 
 		virtual bool Decode(const DataBuffer& input, DataBuffer& output, const std::map<std::string, DataBuffer>& params = std::map<std::string, DataBuffer>());
 		virtual bool Encode(const DataBuffer& input, DataBuffer& output, const std::map<std::string, DataBuffer>& params = std::map<std::string, DataBuffer>());
+		virtual bool DecodeWithContext(Ref<TransformContext> context, const std::map<std::string, DataBuffer>& params = std::map<std::string, DataBuffer>());
 		virtual bool CanDecode(Ref<BinaryView> input) const;
 	};
 
@@ -9011,6 +9016,8 @@ namespace BinaryNinja {
 		    const std::map<std::string, DataBuffer>& params = std::map<std::string, DataBuffer>()) override;
 		virtual bool Encode(const DataBuffer& input, DataBuffer& output,
 		    const std::map<std::string, DataBuffer>& params = std::map<std::string, DataBuffer>()) override;
+		virtual bool DecodeWithContext(Ref<TransformContext> context,
+		    const std::map<std::string, DataBuffer>& params = std::map<std::string, DataBuffer>()) override;
 		virtual bool CanDecode(Ref<BinaryView> input) const override;
 	};
 

binaryninjacore.h

@@ -37,14 +37,14 @@
 // Current ABI version for linking to the core. This is incremented any time
 // there are changes to the API that affect linking, including new functions,
 // new types, or modifications to existing functions or types.
-#define BN_CURRENT_CORE_ABI_VERSION 133
+#define BN_CURRENT_CORE_ABI_VERSION 134
 
 // Minimum ABI version that is supported for loading of plugins. Plugins that
 // are linked to an ABI version less than this will not be able to load and
 // will require rebuilding. The minimum version is increased when there are
 // incompatible changes that break binary compatibility, such as changes to
 // existing types or functions.
-#define BN_MINIMUM_CORE_ABI_VERSION 133
+#define BN_MINIMUM_CORE_ABI_VERSION 134
 
 #ifdef __GNUC__
 	#ifdef BINARYNINJACORE_LIBRARY
@@ -353,7 +353,8 @@ extern "C"
 	typedef enum BNTransformCapabilities
 	{
 		TransformNoCapabilities = 0,
-		TransformSupportsDetection = 1
+		TransformSupportsDetection = 1,
+		TransformSupportsContext = 2
 	} BNTransformCapabilities;
 
 	typedef enum BNTransformSessionMode
@@ -1770,6 +1771,7 @@ extern "C"
 		void (*freeParameters)(BNTransformParameterInfo* params, size_t count);
 		bool (*decode)(void* ctxt, BNDataBuffer* input, BNDataBuffer* output, BNTransformParameter* params, size_t paramCount);
 		bool (*encode)(void* ctxt, BNDataBuffer* input, BNDataBuffer* output, BNTransformParameter* params, size_t paramCount);
+		bool (*decodeWithContext)(void* ctxt, BNTransformContext* context, BNTransformParameter* params, size_t paramCount);
 		bool (*canDecode)(void* ctxt, BNBinaryView* input);
 	} BNCustomTransform;
 
@@ -4634,6 +4636,7 @@ extern "C"
 	BINARYNINJACOREAPI BNTransformType BNGetTransformType(BNTransform* xform);
 	BINARYNINJACOREAPI uint32_t BNGetTransformCapabilities(BNTransform* xform);
 	BINARYNINJACOREAPI bool BNTransformSupportsDetection(BNTransform* xform);
+	BINARYNINJACOREAPI bool BNTransformSupportsContext(BNTransform* xform);
 	BINARYNINJACOREAPI char* BNGetTransformName(BNTransform* xform);
 	BINARYNINJACOREAPI char* BNGetTransformLongName(BNTransform* xform);
 	BINARYNINJACOREAPI char* BNGetTransformGroup(BNTransform* xform);
@@ -4643,6 +4646,7 @@ extern "C"
 	    BNTransform* xform, BNDataBuffer* input, BNDataBuffer* output, BNTransformParameter* params, size_t paramCount);
 	BINARYNINJACOREAPI bool BNEncode(
 	    BNTransform* xform, BNDataBuffer* input, BNDataBuffer* output, BNTransformParameter* params, size_t paramCount);
+	BINARYNINJACOREAPI bool BNDecodeWithContext(BNTransform* xform, BNTransformContext* context, BNTransformParameter* params, size_t paramCount);
 	BINARYNINJACOREAPI bool BNCanDecode(BNTransform* xform, BNBinaryView* input);
 
 	// Transform Context

python/transform.py

@@ -116,6 +116,7 @@ def __init__(self, handle):
 			self._cb.freeParameters = self._cb.freeParameters.__class__(self._free_parameters)
 			self._cb.decode = self._cb.decode.__class__(self._decode)
 			self._cb.encode = self._cb.encode.__class__(self._encode)
+			self._cb.decodeWithContext = self._cb.decodeWithContext.__class__(self._decode_with_context)
 			self._cb.canDecode = self._cb.canDecode.__class__(self._can_decode)
 			self._pending_param_lists = {}
 			self.type = self.__class__.transform_type
@@ -131,6 +132,7 @@ def __init__(self, handle):
 			self.type = TransformType(core.BNGetTransformType(self.handle))
 			self.capabilities = core.BNGetTransformCapabilities(self.handle)
 			self.supports_detection = core.BNTransformSupportsDetection(self.handle)
+			self.supports_context = core.BNTransformSupportsContext(self.handle)
 			self.name = core.BNGetTransformName(self.handle)
 			self.long_name = core.BNGetTransformLongName(self.handle)
 			self.group = core.BNGetTransformGroup(self.handle)
@@ -232,6 +234,21 @@ def _encode(self, ctxt, input_buf, output_buf, params, count):
 			log_error_for_exception("Unhandled Python exception in Transform._encode")
 			return False
 
+	def _decode_with_context(self, ctxt, context, params, count):
+		try:
+			# TODO: Make Python TransformSession and TransformContext objects
+			from . import transform_context
+			context_obj = transform_context.TransformContext(core.BNNewTransformContextReference(context))
+			param_map = {}
+			for i in range(0, count):
+				data = databuffer.DataBuffer(handle=core.BNDuplicateDataBuffer(params[i].value))
+				param_map[params[i].name] = bytes(data)
+			result = self.perform_decode_with_context(context_obj, param_map)
+			return result if result is not None else False
+		except:
+			log_error_for_exception("Unhandled Python exception in Transform._decode_with_context")
+			return False
+
 	def _can_decode(self, ctxt, input):
 		try:
 			input_obj = binaryview.BinaryView(handle=core.BNNewViewReference(input))
@@ -250,6 +267,9 @@ def perform_decode(self, data, params):
 	def perform_encode(self, data, params):
 		return None
 
+	def perform_decode_with_context(self, context, params):
+		return False
+
 	def decode(self, input_buf, params={}):
 		if isinstance(input_buf, int) or isinstance(input_buf, int):
 			return None
@@ -282,6 +302,22 @@ def encode(self, input_buf, params={}):
 			return None
 		return bytes(output_buf)
 
+	def decode_with_context(self, context, params={}):
+		# TODO: Make Python TransformSession and TransformContext objects
+		from . import transform_context
+		if not isinstance(context, transform_context.TransformContext):
+			return None
+		keys = list(params.keys())
+		param_buf = (core.BNTransformParameter * len(keys))()
+		data = []
+		for i in range(0, len(keys)):
+			data.append(databuffer.DataBuffer(params[keys[i]]))
+			param_buf[i].name = keys[i]
+			param_buf[i].value = data[i].handle
+		if not core.BNDecodeWithContext(self.handle, context.handle, param_buf, len(keys)):
+			return False
+		return True
+
 	def can_decode(self, input):
 		"""
 		``can_decode`` checks if this transform can decode the given input.

transform.cpp

@@ -107,6 +107,18 @@ bool Transform::EncodeCallback(
 }
 
 
+bool Transform::DecodeWithContextCallback(void* ctxt, BNTransformContext* context, BNTransformParameter* params, size_t paramCount)
+{
+	map<string, DataBuffer> paramMap;
+	for (size_t i = 0; i < paramCount; i++)
+		paramMap[params[i].name] = DataBuffer(BNDuplicateDataBuffer(params[i].value));
+
+	CallbackRef<Transform> xform(ctxt);
+	Ref<TransformContext> contextRef = new TransformContext(BNNewTransformContextReference(context));
+	return xform->DecodeWithContext(contextRef, paramMap);
+}
+
+
 bool Transform::CanDecodeCallback(void* ctxt, BNBinaryView* input)
 {
 	CallbackRef<Transform> xform(ctxt);
@@ -150,6 +162,7 @@ void Transform::Register(Transform* xform)
 	callbacks.freeParameters = FreeParametersCallback;
 	callbacks.decode = DecodeCallback;
 	callbacks.encode = EncodeCallback;
+	callbacks.decodeWithContext = DecodeWithContextCallback;
 	callbacks.canDecode = CanDecodeCallback;
 	xform->AddRefForRegistration();
 	xform->m_object = BNRegisterTransformTypeWithCapabilities(xform->m_typeForRegister, xform->m_capabilitiesForRegister,
@@ -199,6 +212,12 @@ bool Transform::SupportsDetection() const
 }
 
 
+bool Transform::SupportsContext() const
+{
+	return BNTransformSupportsContext(m_object);
+}
+
+
 string Transform::GetName() const
 {
 	char* name = BNGetTransformName(m_object);
@@ -246,6 +265,12 @@ bool Transform::Encode(const DataBuffer&, DataBuffer&, const map<string, DataBuf
 }
 
 
+bool Transform::DecodeWithContext(Ref<TransformContext>, const map<string, DataBuffer>&)
+{
+	return false;
+}
+
+
 bool Transform::CanDecode(Ref<BinaryView> input) const
 {
 	return false;
@@ -310,6 +335,23 @@ bool CoreTransform::Encode(const DataBuffer& input, DataBuffer& output, const ma
 }
 
 
+bool CoreTransform::DecodeWithContext(Ref<TransformContext> context, const map<string, DataBuffer>& params)
+{
+	BNTransformParameter* list = new BNTransformParameter[params.size()];
+	size_t idx = 0;
+	for (auto& i : params)
+	{
+		list[idx].name = i.first.c_str();
+		list[idx++].value = i.second.GetBufferObject();
+	}
+
+	bool result = BNDecodeWithContext(m_object, context->GetObject(), list, idx);
+
+	delete[] list;
+	return result;
+}
+
+
 bool CoreTransform::CanDecode(Ref<BinaryView> input) const
 {
 	return BNCanDecode(m_object, input->GetObject());