+//// Signature Editing
+
+void SecCodeSigner::Signer::edit(SecCSFlags flags)
+{
+ rep = code->diskRep()->base();
+
+ Universal *fat = state.mNoMachO ? NULL : rep->mainExecutableImage();
+
+ prepareForEdit(flags);
+
+ if (fat != NULL) {
+ editMachO(fat);
+ } else {
+ editArchitectureAgnostic();
+ }
+}
+
+EditableDiskRep *SecCodeSigner::Signer::editMainExecutableRep(DiskRep *rep)
+{
+ EditableDiskRep *mainExecRep = NULL;
+ BundleDiskRep *bundleDiskRep = dynamic_cast<BundleDiskRep*>(rep);
+
+ if (bundleDiskRep) {
+ mainExecRep = dynamic_cast<EditableDiskRep*>(bundleDiskRep->mainExecRep());
+ }
+
+ return mainExecRep;
+}
+
+void SecCodeSigner::Signer::prepareForEdit(SecCSFlags flags) {
+ setDigestAlgorithms(code->hashAlgorithms());
+
+ Universal *machO = (code->diskRep()->mainExecutableIsMachO() ?
+ code->diskRep()->mainExecutableImage() : NULL);
+
+ /* We need at least one architecture in all cases because we index our
+ * RawComponentMaps by architecture. However, only machOs have any
+ * architecture at all, for generic targets there will just be one
+ * RawComponentMap.
+ * So if the main executable is not a machO, we just choose the local
+ * (signer's) main architecture as dummy value for the first element in our pair. */
+ editMainArch = (machO != NULL ? machO->bestNativeArch() : Architecture::local());
+
+ if (machO != NULL) {
+ if (machO->narrowed()) {
+ /* --arch gives us a narrowed SecStaticCode, but because
+ * codesign_allocate always creates or replaces signatures
+ * for all slices, we must operate on the universal
+ * SecStaticCode. Instead, we provide --edit-arch to specify
+ * which slices to edit, the others have their code signature
+ * copied without modifications.
+ */
+ MacOSError::throwMe(errSecCSNotSupported,
+ "Signature editing must be performed on universal binary instead of narrow slice (using --edit-arch instead of --arch).");
+ }
+
+ if (state.mEditArch && !machO->isUniversal()) {
+ MacOSError::throwMe(errSecCSInvalidFlags,
+ "--edit-arch is only valid for universal binaries.");
+ }
+
+ if (state.mEditCMS && machO->isUniversal() && !state.mEditArch) {
+ /* Each slice has its own distinct code signature,
+ * so a CMS blob is only valid for its one slice.
+ * Therefore, replacing all CMS blobs in all slices
+ * with the same blob is rather nonsensical, and we refuse.
+ *
+ * (Universal binaries with only one slice can exist,
+ * and in that case the slice to operate on would be
+ * umambiguous, but we are not treating those binaries
+ * specially and still want --edit-arch for consistency.)
+ */
+ MacOSError::throwMe(errSecCSNotSupported,
+ "CMS editing must be performed on specific slice (specified with --edit-arch).");
+ }
+ }
+
+ void (^editArch)(SecStaticCode *code, Architecture arch) =
+ ^(SecStaticCode *code, Architecture arch) {
+ EditableDiskRep *editRep = dynamic_cast<EditableDiskRep *>(code->diskRep());
+
+ if (editRep == NULL) {
+ MacOSError::throwMe(errSecCSNotSupported,
+ "Signature editing not supported for code of this type.");
+ }
+
+ EditableDiskRep *mainExecRep = editMainExecutableRep(code->diskRep());
+
+ if (mainExecRep != NULL) {
+ // Delegate editing to the main executable if it is an EditableDiskRep.
+ //(Which is the case for machOs.)
+ editRep = mainExecRep;
+ }
+
+ editComponents[arch] = std::make_unique<RawComponentMap>(editRep->createRawComponents());
+
+ if (!state.mEditArch || arch == state.mEditArch) {
+ if (state.mEditCMS) {
+ CFDataRef cms = state.mEditCMS.get();
+ (*editComponents[arch])[cdSignatureSlot] = cms;
+ }
+ }
+ };
+
+ editArch(code, editMainArch);
+
+ code->handleOtherArchitectures(^(Security::CodeSigning::SecStaticCode *subcode) {
+ Universal *fat = subcode->diskRep()->mainExecutableImage();
+ assert(fat && fat->narrowed()); // handleOtherArchitectures gave us a focused architecture slice.
+ Architecture arch = fat->bestNativeArch(); // actually, only architecture for this slice.
+ editArch(subcode, arch);
+ });
+
+ /* The resource dictionary is special, because it is
+ * considered "global" instead of per architecture.
+ * For editing, that means it's usually not embedded
+ * in the main executable's signature if it exists,
+ * but in the containing disk rep (e.g. the
+ * CodeResources file if the rep is a Bundle).
+ */
+ resourceDictData = rep->component(cdResourceDirSlot);
+}
+
+void SecCodeSigner::Signer::editMachO(Universal *fat) {
+ // Mach-O executable at the core - perform multi-architecture signature editing
+ RefPointer<DiskRep::Writer> writer = rep->writer();
+
+ if (state.mPreserveAFSC)
+ writer->setPreserveAFSC(state.mPreserveAFSC);
+
+ unique_ptr<ArchEditor> editor(new MachOEditor(writer, *fat,
+ this->digestAlgorithms(),
+ rep->mainExecutablePath()));
+ assert(editor->count() > 0);
+
+ if (resourceDictData && !editor->attribute(writerNoGlobal)) {
+ // For when the resource dict is "global", e.g. for bundles.
+ editor->component(cdResourceDirSlot, resourceDictData);
+ }
+
+ for (MachOEditor::Iterator it = editor->begin(); it != editor->end(); ++it) {
+ MachOEditor::Arch &arch = *it->second;
+ arch.source.reset(fat->architecture(it->first)); // transfer ownership
+
+ if (resourceDictData && editor->attribute(writerNoGlobal)) {
+ // Technically possible to embed a resource dict in the embedded sig.
+ arch.component(cdResourceDirSlot, resourceDictData);
+ }
+
+ for (auto const &entry : *editComponents[arch.architecture]) {
+ CodeDirectory::Slot slot = entry.first;
+ CFDataRef data = entry.second.get();
+ arch.component(slot, data);
+ }
+
+ /* We must preserve the original superblob's size, as the size is
+ * also in the macho's load commands, which are itself covered
+ * by the signature. */
+ arch.blobSize = arch.source->signingLength();
+ }
+
+ editor->allocate();
+
+ for (MachOEditor::Iterator it = editor->begin(); it != editor->end(); ++it) {
+ MachOEditor::Arch &arch = *it->second;
+ editor->reset(arch);
+
+ if (!state.mDryRun) {
+ EmbeddedSignatureBlob *blob = arch.make();
+ editor->write(arch, blob); // takes ownership of blob
+ }
+ }
+
+ if (!state.mDryRun) {
+ editor->commit();
+ }
+
+}
+
+void SecCodeSigner::Signer::editArchitectureAgnostic()
+{
+ if (state.mDryRun) {
+ return;
+
+ }
+ // non-Mach-O executable - single-instance signature editing
+ RefPointer<DiskRep::Writer> writer = rep->writer();
+
+ if(state.mPreserveAFSC)
+ writer->setPreserveAFSC(state.mPreserveAFSC);
+
+ for (auto const &entry : *editComponents[editMainArch]) {
+ CodeDirectory::Slot slot = entry.first;
+ CFDataRef data = entry.second.get();
+
+ writer->component(slot, data);
+ }
+
+ // commit to storage
+ writer->flush();
+}
+
projects / apple / security.git / blobdiff