Venkat Ramachandran

18 papers C 3Misc 4Journal 6Unranked 5
YearRankTypeTitle / Venue / Authors
2010 J jnl
Eur. J. Control
S. Mustafa Azizi, Brandon W. Gordon, Venkat Ramachandran
2008 J jnl
J. Circuits Syst. Comput.
Venkat Ramachandran, Ravi Prakash Ramachandran, Christian S. Gargour
2007 J jnl
J. Comput.
Venkat Ramachandran, Christian S. Gargour, Ravi Prakash Ramachandran
2006 C conf
ACC
Seyve M. Azizi, Brandon W. Gordon, Venkat Ramachandran
2006 conf
CCECE
Jun Xiao, Venkat Ramachandran
2006 conf
APCCAS
Christian S. Gargour, Venkat Ramachandran, Ravi Prakash Ramachandran
2005 C conf
CCA
Jian Qi, Vijay K. Sood, Venkat Ramachandran
2005 conf
ISCAS (3)
Venkat Ramachandran, Majid Ahmadi, Christian S. Gargour
2004 J jnl
J. Circuits Syst. Comput.
Christian S. Gargour, Venkat Ramachandran, Ravi Prakash Ramachandran
2001 J jnl
Comput. Electr. Eng.
A. Lee, Majid Ahmadi, Venkat Ramachandran, Christian S. Gargour
2001 conf
ISCAS (2)
Christian S. Gargour, Venkat Ramachandran, Ravi Prakash Ramachandran
2001 conf
ISCAS (2)
Venkat Ramachandran, Ravi Prakash Ramachandran, Christian S. Gargour
1994 C conf
ISCAS
Venkat Ramachandran, Majid Ahmadi, Christian S. Gargour
1985 J jnl
IEEE Trans. Acoust. Speech Signal Process.
Majid Ahmadi, M. Boraie, Venkat Ramachandran, Christian S. Gargour
1984 Misc conf
ICASSP
M. Omair Ahmad, Majid Ahmadi, Venkat Ramachandran
1983 Misc conf
ICASSP
Majid Ahmadi, S. Golikeri, Venkat Ramachandran
1983 Misc conf
ICASSP
M. Omair Ahmad, Majid Ahmadi, Venkat Ramachandran
1981 Misc conf
ICASSP
Majid Ahmadi, Venkat Ramachandran
redb/extractors/decompiler/_archive/GhidraDecompilerScript-latest.java
← Index redb/extractors/decompiler/_archive/GhidraDecompilerScript-latest.java java
import ghidra.app.script.GhidraScript;
import ghidra.program.model.listing.*;
import ghidra.app.decompiler.*;
import ghidra.program.model.block.*;
import ghidra.program.model.symbol.*;
import ghidra.program.model.pcode.*;
import ghidra.program.model.address.*;
import org.json.JSONObject;
import org.json.JSONArray;
import java.security.MessageDigest;
import java.nio.charset.StandardCharsets;

public class GhidraDecompilerScript extends GhidraScript {
    private DecompInterface decompInterface;
    private BasicBlockModel basicBlockModel;
    
    @Override
    public void run() throws Exception {
        // Get binary hash and filepath from arguments
        String[] args = getScriptArgs();
        if (args.length < 2) {
            System.err.println("{\"error\": \"Both SHA256 and filepath arguments are required\"}");
            return;
        }
        String sha256 = args[0];
        String filepath = args[1];

        // Initialize analysis components
        setupDecompiler();
        basicBlockModel = new BasicBlockModel(currentProgram);

        // Create the main JSON object for output
        JSONObject output = new JSONObject();
        output.put("sha256", sha256);
        output.put("decompiled", new JSONArray());
        output.put("disassembled", new JSONArray());
        output.put("cfg", new JSONArray());

        // Process all functions
        FunctionIterator functions = currentProgram.getFunctionManager().getFunctions(true);
        for (Function function : functions) {
            processFunction(function, output);
        }

        // Output the final JSON to stdout
        System.out.println(output.toString());
    }

    private void setupDecompiler() {
        decompInterface = new DecompInterface();
        DecompileOptions options = new DecompileOptions();
        decompInterface.setOptions(options);
        decompInterface.openProgram(currentProgram);
    }

    private void processFunction(Function function, JSONObject output) {
        Address entry = function.getEntryPoint();
        String functionName = function.getName();
        String functionAddress = entry.toString();

        // Process decompiled code
        processDecompiledCode(function, output.getJSONArray("decompiled"), 
                            functionName, functionAddress);

        // Process disassembled code
        processDisassembledCode(function, output.getJSONArray("disassembled"), 
                              functionName, functionAddress);

        // Process CFG
        processCFG(function, output.getJSONArray("cfg"), functionAddress);
    }

    private void processDecompiledCode(Function function, JSONArray decompArray, 
                                     String functionName, String functionAddress) {
        DecompileResults results = decompInterface.decompileFunction(function, 30, monitor);
        if (results.decompileCompleted()) {
            String decompiledCode = results.getDecompiledFunction().getC();
            String contentHash = calculateHash(decompiledCode);

            JSONObject functionObj = new JSONObject();
            functionObj.put("decompiled_content_hash", contentHash);
            functionObj.put("decompiled_function_name", functionName);
            functionObj.put("decompiled_function_address", functionAddress);
            functionObj.put("decompiled_function", decompiledCode);
            
            decompArray.put(functionObj);
        }
    }

    private void processDisassembledCode(Function function, JSONArray disasmArray, 
                                       String functionName, String functionAddress) {
        try {
            StringBuilder disassembly = new StringBuilder();
            StringBuilder normalized = new StringBuilder();
            int instructionCount = 0;

            Listing listing = currentProgram.getListing();
            AddressSetView functionBody = function.getBody();
            InstructionIterator instructions = listing.getInstructions(functionBody, true);

            while (instructions.hasNext()) {
                try {
                    Instruction instr = instructions.next();
                    String disasmLine = instr.toString();
                    disassembly.append(disasmLine).append("\n");
                    normalized.append(normalizeInstruction(disasmLine)).append("\n");
                    instructionCount++;
                } catch (Exception e) {
                    System.err.println("Error processing instruction in " + functionName + ": " + e.getMessage());
                }
            }

            String disassembledCode = disassembly.toString();
            String contentHash = calculateHash(disassembledCode);

            JSONObject functionObj = new JSONObject();
            functionObj.put("disassembled_content_hash", contentHash);
            functionObj.put("disassembled_function_name", functionName);
            functionObj.put("disassembled_function_address", functionAddress);
            functionObj.put("disassembled_function", disassembledCode);
            functionObj.put("normalized_disassembly", normalized.toString());
            functionObj.put("instruction_count", instructionCount);

            // Set similarity-related fields to null for now
            functionObj.put("minhash_signature", JSONObject.NULL);
            functionObj.put("opcode_frequency_vector", JSONObject.NULL);
            functionObj.put("api_calls_vector", JSONObject.NULL);
            functionObj.put("instruction_embedding", JSONObject.NULL);

            disasmArray.put(functionObj);
        } catch (Exception e) {
            System.err.println("Error processing disassembly for " + functionName + ": " + e.getMessage());
        }
    }

    private void processCFG(Function function, JSONArray cfgArray, String functionAddress) {
        try {
            CodeBlockIterator blocks = basicBlockModel.getCodeBlocksContaining(
                function.getBody(), monitor);

            while (blocks.hasNext()) {
                CodeBlock block = blocks.next();
                String blockInstructions = getBlockInstructions(block);
                String blockId = calculateHash(blockInstructions);

                JSONObject blockObj = new JSONObject();
                blockObj.put("block_id", blockId);
                blockObj.put("function_address", functionAddress);
                blockObj.put("block_instructions", blockInstructions);

                // Get successor blocks
                CodeBlockReferenceIterator successors = block.getDestinations(monitor);
                JSONArray successorAddresses = new JSONArray();
                while (successors.hasNext()) {
                    CodeBlockReference ref = successors.next();
                    successorAddresses.put(ref.getDestinationAddress().toString());
                }
                blockObj.put("successor_blocks", successorAddresses);

                cfgArray.put(blockObj);
            }
        } catch (Exception e) {
            System.err.println("{\"error\": \"Error processing CFG: " + 
                             e.getMessage().replace("\"", "'") + "\"}");
        }
    }

    private String normalizeInstruction(String instruction) {
        return instruction.replaceAll("0x[0-9a-fA-F]+", "IMM")
                        .replaceAll("\\b\\d+\\b", "NUM");
    }

    private String getBlockInstructions(CodeBlock block) {
        StringBuilder instructions = new StringBuilder();
        AddressIterator addresses = block.getAddresses(true);
        while (addresses.hasNext()) {
            Address addr = addresses.next();
            Instruction instr = currentProgram.getListing().getInstructionAt(addr);
            if (instr != null) {
                instructions.append(instr.toString()).append("\n");
            }
        }
        return instructions.toString();
    }

    private String calculateHash(String content) {
        try {
            MessageDigest digest = MessageDigest.getInstance("SHA-256");
            byte[] hash = digest.digest(content.getBytes(StandardCharsets.UTF_8));
            StringBuilder hexString = new StringBuilder();
            for (byte b : hash) {
                hexString.append(String.format("%02x", b));
            }
            return hexString.toString();
        } catch (Exception e) {
            System.err.println("{\"error\": \"Error calculating hash\"}");
            return "";
        }
    }
}