161 lines
4.0 KiB
Java
161 lines
4.0 KiB
Java
/* ###
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* IP: GHIDRA
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* REVIEWED: YES
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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//Resolves relative references computed off EBX.
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//This will resolve references to strings in the "__cstring" section.
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//@category Mac OS X
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import ghidra.app.script.GhidraScript;
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import ghidra.program.model.address.Address;
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import ghidra.program.model.lang.Register;
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import ghidra.program.model.listing.*;
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import ghidra.program.model.scalar.Scalar;
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import ghidra.program.model.symbol.RefType;
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import ghidra.program.model.symbol.Reference;
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import ghidra.util.Conv;
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public class ResolveReferencesRelativeToEbxScript extends GhidraScript {
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private Register EBX;
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@Override
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public void run() throws Exception {
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EBX = currentProgram.getLanguage().getRegister("EBX");
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FunctionIterator functions = currentProgram.getListing().getFunctions(true);
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while ( functions.hasNext() ) {
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if ( monitor.isCancelled() ) {
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break;
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}
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Function function = functions.next();
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monitor.setMessage( function.getName() );
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loopOverInstructionsInFunction( function );
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function = getFunctionAfter( function );
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}
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}
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private void loopOverInstructionsInFunction(Function function) {
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// find all CALL instructions
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long ebx = -1;
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InstructionIterator instructions = currentProgram.getListing().getInstructions( function.getBody(), true ) ;
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while ( instructions.hasNext() ) {
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Instruction instruction = instructions.next();
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if ( monitor.isCancelled() ) {
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break;
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}
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if ( ebx == -1 ) {
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ebx = getValueForEBX( instruction );
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}
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if ( ebx == -1 ) {
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continue;
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}
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for (int i = 0 ; i < instruction.getNumOperands() ; ++i ) {
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Object [] opObjects = instruction.getOpObjects(i);
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if ( opObjects.length == 2 ) {
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if (opObjects[ 0 ] instanceof Scalar && opObjects[ 1 ] instanceof Register ) {
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Scalar scalar = (Scalar) opObjects[ 0 ];
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Register register = (Register) opObjects[ 1 ];
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if ( register.equals( EBX ) ) {
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Address address = toAddr( (ebx + scalar.getUnsignedValue()) & Conv.INT_MASK );
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if ( isValid( address ) ) {
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removeReferencesFrom(instruction);
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Reference reference = createMemoryReference( instruction, 1, address, RefType.DATA );
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setReferencePrimary( reference );
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println( "Creating reference from " + instruction.getMinAddress() + " to " + address );
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}
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}
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}
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}
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}
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}
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}
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private boolean isValid(Address address) {
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Instruction instruction = getInstructionContaining( address );
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if ( instruction != null ) {
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Address min = instruction.getMinAddress();
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if ( address.compareTo( min ) > 0 ) {
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return false; //off-cut
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}
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}
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Data data = getDataContaining( address );
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if ( data != null ) {
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Address min = data.getMinAddress();
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if ( address.compareTo( min ) > 0 ) {
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return false; //off-cut
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}
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}
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return currentProgram.getMemory().contains( address );
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}
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private void removeReferencesFrom(Instruction instruction) {
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Reference [] referencesFrom = instruction.getReferencesFrom();
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for (Reference reference : referencesFrom) {
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removeReference( reference );
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}
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}
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private long getValueForEBX(Instruction instruction) {
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if ( instruction.getMnemonicString().equals( "CALL" ) ) {
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Address nextInstructionAddress = instruction.getMaxAddress().add( 1 );
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Reference [] referencesFrom = instruction.getReferencesFrom();
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if ( referencesFrom.length == 1) {
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if ( referencesFrom[0].getToAddress().equals( nextInstructionAddress ) ) {
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return nextInstructionAddress.getOffset();
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}
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}
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}
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return -1;
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}
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}
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