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Fix Leb128 parsing of WasmLoader. #3

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Fix Leb128 parsing of WasmLoader. #3

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9 changes: 7 additions & 2 deletions src/main/java/wasm/analysis/MetaInstruction.java
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Original file line number Diff line number Diff line change
@@ -1,13 +1,14 @@
package wasm.analysis;

import java.io.IOException;
import java.util.ArrayList;

import ghidra.app.util.bin.format.dwarf4.LEB128;
import ghidra.program.model.address.Address;
import ghidra.program.model.lang.InjectContext;
import ghidra.program.model.listing.Program;
import ghidra.program.model.mem.MemoryAccessException;
import ghidra.program.model.pcode.Varnode;
import wasm.format.Leb128;
import wasm.format.WasmFuncSignature;
import wasm.format.sections.structures.WasmFuncType;
import wasm.pcodeInject.PcodeHelper;
Expand Down Expand Up @@ -113,7 +114,11 @@ public static MetaInstruction create(Type ty, InjectContext con, Program p) {
public static long getLeb128Operand(Program p, Address brAddress) throws MemoryAccessException {
byte[] buf = new byte[16];
p.getMemory().getBytes(brAddress.add(1), buf); //add 1 to go past the opcode
return Leb128.readUnsignedLeb128(buf);
try {
return LEB128.decode(buf,false);
} catch (IOException e) {
throw new MemoryAccessException("Error while decoding leb128 :"+e.getMessage());
}
}

public abstract Type getType();
Expand Down
231 changes: 0 additions & 231 deletions src/main/java/wasm/format/Leb128.java
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This file was deleted.

15 changes: 7 additions & 8 deletions src/main/java/wasm/format/sections/WasmCodeSection.java
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Original file line number Diff line number Diff line change
Expand Up @@ -5,22 +5,21 @@
import java.util.List;

import ghidra.app.util.bin.BinaryReader;
import ghidra.app.util.bin.StructConverter;
import ghidra.program.model.data.DataType;
import ghidra.app.util.bin.format.dwarf4.LEB128;
import ghidra.program.model.data.ArrayDataType;
import ghidra.program.model.data.Structure;
import ghidra.program.model.data.StructureDataType;
import ghidra.util.exception.DuplicateNameException;
import wasm.format.Leb128;
import wasm.format.sections.structures.WasmFunctionBody;
import static ghidra.app.util.bin.StructConverter.BYTE;

public class WasmCodeSection implements WasmPayload {

private Leb128 count;
private LEB128 count;
List<WasmFunctionBody> functions = new ArrayList <WasmFunctionBody>();

public WasmCodeSection (BinaryReader reader) throws IOException {
count = new Leb128(reader);
for (int i =0; i < count.getValue(); ++i) {
count = LEB128.readUnsignedValue(reader);
for (int i =0; i < count.asInt32(); ++i) {
functions.add(new WasmFunctionBody(reader));
}
}
Expand All @@ -31,7 +30,7 @@ public List<WasmFunctionBody> getFunctions() {

@Override
public void addToStructure(Structure structure) throws IllegalArgumentException, DuplicateNameException, IOException {
structure.add(count.toDataType(), count.toDataType().getLength(), "count", null);
structure.add( new ArrayDataType( BYTE, count.getLength(), BYTE.getLength( ) ), "count", null );
int function_id = 0;
for (WasmFunctionBody function: functions) {
structure.add(function.toDataType(), function.toDataType().getLength(), "function_" + function_id, null);
Expand Down
17 changes: 9 additions & 8 deletions src/main/java/wasm/format/sections/WasmCustomSection.java
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Original file line number Diff line number Diff line change
@@ -1,21 +1,22 @@
package wasm.format.sections;

import static ghidra.app.util.bin.StructConverter.BYTE;

import java.io.IOException;

import ghidra.app.util.bin.BinaryReader;
import ghidra.app.util.bin.StructConverter;
import ghidra.program.model.data.DataType;
import ghidra.app.util.bin.format.dwarf4.LEB128;
import ghidra.program.model.data.ArrayDataType;
import ghidra.program.model.data.Structure;
import ghidra.program.model.data.StructureDataType;
import ghidra.util.exception.DuplicateNameException;
import wasm.format.Leb128;

public class WasmCustomSection implements WasmPayload {
Leb128 namelen;
LEB128 namelen;
String name;
byte[] contents;

protected WasmCustomSection (Leb128 namelen, String name, BinaryReader reader, int contentlen) throws IOException {
protected WasmCustomSection (LEB128 namelen, String name, BinaryReader reader, int contentlen) throws IOException {
this.namelen = namelen;
this.name = name;
contents = reader.readNextByteArray(contentlen);
Expand All @@ -24,8 +25,8 @@ protected WasmCustomSection (Leb128 namelen, String name, BinaryReader reader, i
public static WasmCustomSection create(BinaryReader reader, long len) throws IOException {
long readUntil = reader.getPointerIndex() + len;

Leb128 namelen = new Leb128(reader);
String name = new String(reader.readNextByteArray((int)namelen.getValue()));
LEB128 namelen = LEB128.readUnsignedValue(reader);
String name = new String(reader.readNextByteArray((int)namelen.asInt32()));

int contentlen = (int)(readUntil - reader.getPointerIndex());

Expand All @@ -38,7 +39,7 @@ public static WasmCustomSection create(BinaryReader reader, long len) throws IOE

@Override
public void addToStructure(Structure structure) throws IllegalArgumentException, DuplicateNameException, IOException {
structure.add(namelen.toDataType(), "name_len", null);
structure.add( new ArrayDataType( BYTE, namelen.getLength(), BYTE.getLength( ) ), "name_len", null );
structure.add(StructConverter.STRING, name.length(), "name", null);
structure.add(StructConverter.STRING, contents.length, "contents", null);
}
Expand Down
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