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GP-1986: Fixed a "hash has changed" exception that would sometimes occur

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when extracting .dylib files from a dyld_shared_cache file system.
This commit is contained in:
Ryan Kurtz
2022-05-03 04:48:14 -04:00
parent afb63d811c
commit 94975a236f
1 changed files with 43 additions and 38 deletions
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81
Ghidra/Features/FileFormats/src/main/java/ghidra/file/formats/ios/dyldcache/DyldCacheDylibExtractor.java
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@@ -16,8 +16,7 @@
package ghidra.file.formats.ios.dyldcache; package ghidra.file.formats.ios.dyldcache;
import java.io.IOException; import java.io.IOException;
import java.util.HashMap; import java.util.*;
import java.util.Map;
import ghidra.app.util.bin.*; import ghidra.app.util.bin.*;
import ghidra.app.util.bin.format.macho.*; import ghidra.app.util.bin.format.macho.*;
@@ -104,7 +103,7 @@ public class DyldCacheDylibExtractor {
if (segment.getSegmentName().equals(SegmentNames.SEG_TEXT) && if (segment.getSegmentName().equals(SegmentNames.SEG_TEXT) &&
segment.getFileOffset() == 0) { segment.getFileOffset() == 0) {
segment.setFileOffset(dylibOffset); segment.setFileOffset(dylibOffset);
packedSegmentAdjustments.put(segment, (int)dylibOffset); packedSegmentAdjustments.put(segment, (int) dylibOffset);
} }
} }
@@ -158,16 +157,18 @@ public class DyldCacheDylibExtractor {
/** /**
* Fixes up the bytes at the given DYLD file offset to map to the correct offset in the * Fixes up the bytes at the given DYLD file offset to map to the correct offset in the
* packed DYLIB * packed DYLIB. The provided file offset is assumed to map to a field in in a load
* command.
* *
* @param fileOffset The DYLD file offset to fix-up * @param fileOffset The DYLD file offset to fix-up
* @param adjustment An value to add to the bytes at the given DYLD file offset prior to * @param adjustment An value to add to the bytes at the given DYLD file offset prior to
* looking them up in the packed DYLIB * looking them up in the packed DYLIB
* @param size The number of bytes to fix-up (must be 4 or 8) * @param size The number of bytes to fix-up (must be 4 or 8)
* @param segment The segment that the value at the file offset is associated with
* @throws IOException If there was an IO-related error * @throws IOException If there was an IO-related error
* @throws IllegalArgumentException if size is an unsupported value * @throws IllegalArgumentException if size is an unsupported value
*/ */
public void fixup(long fileOffset, long adjustment, int size) public void fixup(long fileOffset, long adjustment, int size, SegmentCommand segment)
throws IOException, IllegalArgumentException { throws IOException, IllegalArgumentException {
if (size != 4 && size != 8) { if (size != 4 && size != 8) {
throw new IllegalArgumentException("Size must be 4 or 8 (got " + size + ")"); throw new IllegalArgumentException("Size must be 4 or 8 (got " + size + ")");
@@ -176,9 +177,10 @@ public class DyldCacheDylibExtractor {
value += adjustment; value += adjustment;
try { try {
byte[] newBytes = toBytes(getPackedOffset(value), size); byte[] newBytes = toBytes(getPackedOffset(value, segment), size);
System.arraycopy(newBytes, 0, packed, (int) getPackedOffset(fileOffset), SegmentCommand textSegment = header.getSegment(SegmentNames.SEG_TEXT);
newBytes.length); System.arraycopy(newBytes, 0, packed,
(int) getPackedOffset(fileOffset, textSegment), newBytes.length);
} }
catch (NotFoundException e) { catch (NotFoundException e) {
Msg.warn(this, e.getMessage()); Msg.warn(this, e.getMessage());
@@ -187,34 +189,33 @@ public class DyldCacheDylibExtractor {
/** /**
* Fixes up the bytes at the given DYLD file offset to map to the correct offset in the * Fixes up the bytes at the given DYLD file offset to map to the correct offset in the
* packed DYLIB * packed DYLIB. The provided file offset is assumed to map to a field in in a load
* command.
* *
* @param fileOffset The DYLD file offset to fix-up * @param fileOffset The DYLD file offset to fix-up
* @param size The number of bytes to fix-up (must be 4 or 8) * @param size The number of bytes to fix-up (must be 4 or 8)
* @param segment The segment that the file offset is associated with
* @throws IOException If there was an IO-related error * @throws IOException If there was an IO-related error
* @throws IllegalArgumentException if size is an unsupported value * @throws IllegalArgumentException if size is an unsupported value
*/ */
public void fixup(long fileOffset, int size) throws IOException, IllegalArgumentException { public void fixup(long fileOffset, int size, SegmentCommand segment)
fixup(fileOffset, 0, size); throws IOException, IllegalArgumentException {
fixup(fileOffset, 0, size, segment);
} }
/** /**
* Converts the given DYLD file offset to an offset into the packed DYLIB * Converts the given DYLD file offset to an offset into the packed DYLIB
* *
* @param fileOffset The DYLD file offset to convert * @param fileOffset The DYLD file offset to convert
* @param segment The segment that contains the file offset; null if unknown
* @return An offset into the packed DYLIB * @return An offset into the packed DYLIB
* @throws NotFoundException If there was no corresponding DYLIB offset * @throws NotFoundException If there was no corresponding DYLIB offset
*/ */
private long getPackedOffset(long fileOffset) throws NotFoundException { private long getPackedOffset(long fileOffset, SegmentCommand segment)
for (SegmentCommand segment : packedSegmentStarts.keySet()) { throws NotFoundException {
long size = segment.getFileSize(); Integer segmentStart = packedSegmentStarts.get(segment);
if (size == 0) { if (segmentStart != null) {
size = segment.getVMsize(); return fileOffset - segment.getFileOffset() + segmentStart;
}
if (fileOffset >= segment.getFileOffset() &&
fileOffset < segment.getFileOffset() + size) {
return fileOffset - segment.getFileOffset() + packedSegmentStarts.get(segment);
}
} }
throw new NotFoundException( throw new NotFoundException(
"Failed to convert DYLD file offset to packed DYLIB offset: " + "Failed to convert DYLD file offset to packed DYLIB offset: " +
@@ -321,7 +322,7 @@ public class DyldCacheDylibExtractor {
long adjustment = packedSegmentAdjustments.getOrDefault(segment, 0); long adjustment = packedSegmentAdjustments.getOrDefault(segment, 0);
if (segment.getFileOffset() > 0) { if (segment.getFileOffset() > 0) {
fixup(segment.getStartIndex() + (is64bit ? 0x28 : 0x20), adjustment, fixup(segment.getStartIndex() + (is64bit ? 0x28 : 0x20), adjustment,
is64bit ? 8 : 4); is64bit ? 8 : 4, segment);
} }
long sectionStartIndex = segment.getStartIndex() + (is64bit ? 0x48 : 0x38); long sectionStartIndex = segment.getStartIndex() + (is64bit ? 0x48 : 0x38);
for (Section section : segment.getSections()) { for (Section section : segment.getSections()) {
@@ -333,10 +334,10 @@ public class DyldCacheDylibExtractor {
// the adjustment despite the segment needed it. We can expect to see warnings // the adjustment despite the segment needed it. We can expect to see warnings
// in that particular version. // in that particular version.
if (section.getOffset() > 0 && section.getSize() > 0) { if (section.getOffset() > 0 && section.getSize() > 0) {
fixup(sectionStartIndex + (is64bit ? 0x30 : 0x28), adjustment, 4); fixup(sectionStartIndex + (is64bit ? 0x30 : 0x28), adjustment, 4, segment);
} }
if (section.getRelocationOffset() > 0) { if (section.getRelocationOffset() > 0) {
fixup(sectionStartIndex + (is64bit ? 0x38 : 0x30), adjustment, 4); fixup(sectionStartIndex + (is64bit ? 0x38 : 0x30), adjustment, 4, segment);
} }
sectionStartIndex += is64bit ? 0x50 : 0x44; sectionStartIndex += is64bit ? 0x50 : 0x44;
} }
@@ -350,11 +351,12 @@ public class DyldCacheDylibExtractor {
* @throws IOException If there was an IO-related issue performing the fix-up * @throws IOException If there was an IO-related issue performing the fix-up
*/ */
private void fixupSymbolTable(SymbolTableCommand cmd) throws IOException { private void fixupSymbolTable(SymbolTableCommand cmd) throws IOException {
SegmentCommand segment = header.getSegment(SegmentNames.SEG_LINKEDIT);
if (cmd.getSymbolOffset() > 0) { if (cmd.getSymbolOffset() > 0) {
fixup(cmd.getStartIndex() + 0x8, 4); fixup(cmd.getStartIndex() + 0x8, 4, segment);
} }
if (cmd.getStringTableOffset() > 0) { if (cmd.getStringTableOffset() > 0) {
fixup(cmd.getStartIndex() + 0x10, 4); fixup(cmd.getStartIndex() + 0x10, 4, segment);
} }
} }
@@ -366,23 +368,24 @@ public class DyldCacheDylibExtractor {
* @throws IOException If there was an IO-related issue performing the fix-up * @throws IOException If there was an IO-related issue performing the fix-up
*/ */
private void fixupDynamicSymbolTable(DynamicSymbolTableCommand cmd) throws IOException { private void fixupDynamicSymbolTable(DynamicSymbolTableCommand cmd) throws IOException {
SegmentCommand segment = header.getSegment(SegmentNames.SEG_LINKEDIT);
if (cmd.getTableOfContentsOffset() > 0) { if (cmd.getTableOfContentsOffset() > 0) {
fixup(cmd.getStartIndex() + 0x20, 4); fixup(cmd.getStartIndex() + 0x20, 4, segment);
} }
if (cmd.getModuleTableOffset() > 0) { if (cmd.getModuleTableOffset() > 0) {
fixup(cmd.getStartIndex() + 0x28, 4); fixup(cmd.getStartIndex() + 0x28, 4, segment);
} }
if (cmd.getReferencedSymbolTableOffset() > 0) { if (cmd.getReferencedSymbolTableOffset() > 0) {
fixup(cmd.getStartIndex() + 0x30, 4); fixup(cmd.getStartIndex() + 0x30, 4, segment);
} }
if (cmd.getIndirectSymbolTableOffset() > 0) { if (cmd.getIndirectSymbolTableOffset() > 0) {
fixup(cmd.getStartIndex() + 0x38, 4); fixup(cmd.getStartIndex() + 0x38, 4, segment);
} }
if (cmd.getExternalRelocationOffset() > 0) { if (cmd.getExternalRelocationOffset() > 0) {
fixup(cmd.getStartIndex() + 0x40, 4); fixup(cmd.getStartIndex() + 0x40, 4, segment);
} }
if (cmd.getLocalRelocationOffset() > 0) { if (cmd.getLocalRelocationOffset() > 0) {
fixup(cmd.getStartIndex() + 0x48, 4); fixup(cmd.getStartIndex() + 0x48, 4, segment);
} }
} }
@@ -394,20 +397,21 @@ public class DyldCacheDylibExtractor {
* @throws IOException If there was an IO-related issue performing the fix-up * @throws IOException If there was an IO-related issue performing the fix-up
*/ */
private void fixupDyldInfo(DyldInfoCommand cmd) throws IOException { private void fixupDyldInfo(DyldInfoCommand cmd) throws IOException {
SegmentCommand segment = header.getSegment(SegmentNames.SEG_LINKEDIT);
if (cmd.getRebaseOffset() > 0) { if (cmd.getRebaseOffset() > 0) {
fixup(cmd.getStartIndex() + 0x8, 4); fixup(cmd.getStartIndex() + 0x8, 4, segment);
} }
if (cmd.getBindOffset() > 0) { if (cmd.getBindOffset() > 0) {
fixup(cmd.getStartIndex() + 0x10, 4); fixup(cmd.getStartIndex() + 0x10, 4, segment);
} }
if (cmd.getWeakBindOffset() > 0) { if (cmd.getWeakBindOffset() > 0) {
fixup(cmd.getStartIndex() + 0x18, 4); fixup(cmd.getStartIndex() + 0x18, 4, segment);
} }
if (cmd.getLazyBindOffset() > 0) { if (cmd.getLazyBindOffset() > 0) {
fixup(cmd.getStartIndex() + 0x20, 4); fixup(cmd.getStartIndex() + 0x20, 4, segment);
} }
if (cmd.getExportOffset() > 0) { if (cmd.getExportOffset() > 0) {
fixup(cmd.getStartIndex() + 0x28, 4); fixup(cmd.getStartIndex() + 0x28, 4, segment);
} }
} }
@@ -419,8 +423,9 @@ public class DyldCacheDylibExtractor {
* @throws IOException If there was an IO-related issue performing the fix-up * @throws IOException If there was an IO-related issue performing the fix-up
*/ */
private void fixupLinkEditData(LinkEditDataCommand cmd) throws IOException { private void fixupLinkEditData(LinkEditDataCommand cmd) throws IOException {
SegmentCommand segment = header.getSegment(SegmentNames.SEG_LINKEDIT);
if (cmd.getDataOffset() > 0) { if (cmd.getDataOffset() > 0) {
fixup(cmd.getStartIndex() + 0x8, 4); fixup(cmd.getStartIndex() + 0x8, 4, segment);
} }
} }
} }