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[vm] Add LC_ENCRYPTION_INFO(_64) load command to iOS snapshots.
When uploading to the App Store, the program must contain an LC_ENCRYPTION_INFO segment in the Mach-O header so the App Store can appropriately modify it for its purposes without changing the header size and/or offsets/addresses in the rest of the shared object. By default, the load command is only added to iOS snapshots, but it can be added to any Mach-O snapshot using the --macho-encryptable command line option. TEST=vm/dart/use_macho_options_test Cq-Include-Trybots: luci.dart.try:vm-aot-mac-debug-x64-try,vm-aot-mac-debug-arm64-try,vm-aot-linux-debug-x64-try Change-Id: I4e79fd9cfb9ba9d49707ec209eca3fee1cefc28c Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/475040 Reviewed-by: Alexander Markov <[email protected]> Commit-Queue: Tess Strickland <[email protected]>
1 parent 87005f5 commit 8cbf864

4 files changed

Lines changed: 208 additions & 16 deletions

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‎pkg/native_stack_traces/lib/src/macho.dart‎

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Original file line numberDiff line numberDiff line change
@@ -130,6 +130,8 @@ class LoadCommand {
130130
static const LC_UUID = 0x1b;
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static const LC_RPATH = 0x1c | LC_REQ_DYLD;
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static const LC_CODE_SIGNATURE = 0x1d; // Only used in vm/dart tests.
133+
static const LC_ENCRYPTION_INFO = 0x21;
134+
static const LC_ENCRYPTION_INFO_64 = 0x2c;
133135
static const LC_BUILD_VERSION = 0x32;
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static LoadCommand fromReader(Reader reader) {
@@ -156,6 +158,9 @@ class LoadCommand {
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command = DylibCommand.fromReader(reader, cmd, cmdsize);
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case LC_RPATH:
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command = RunPathCommand.fromReader(reader, cmd, cmdsize);
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case LC_ENCRYPTION_INFO:
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case LC_ENCRYPTION_INFO_64:
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command = EncryptionInfoCommand.fromReader(reader, cmd, cmdsize);
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default:
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break;
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}
@@ -602,6 +607,38 @@ class BuildVersionCommand extends LoadCommand {
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}
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}
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610+
class EncryptionInfoCommand extends LoadCommand {
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final int fileOffset;
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final int fileSize;
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final int cryptId;
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EncryptionInfoCommand._(
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super.cmd, super.cmdsize, this.fileOffset, this.fileSize, this.cryptId)
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: super._();
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static EncryptionInfoCommand fromReader(Reader reader, int cmd, int cmdsize) {
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final fileOffset = _readMachOUint32(reader);
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final fileSize = _readMachOUint32(reader);
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final cryptId = _readMachOUint32(reader);
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if (cmd == LoadCommand.LC_ENCRYPTION_INFO_64) {
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_readMachOUint32(reader); // padding
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}
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return EncryptionInfoCommand._(cmd, cmdsize, fileOffset, fileSize, cryptId);
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}
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@override
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void writeToStringBuffer(StringBuffer buffer) {
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buffer
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..writeln('Encryption info: ')
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..write(' File offset: ')
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..writeln(paddedHex(fileOffset, 4))
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..write(' File size: ')
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..writeln(fileSize)
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..write(' Crypt id: ')
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..writeln(cryptId);
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}
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}
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class MachOHeader {
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final int magic;
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final int cputype;

‎runtime/platform/mach_o.h‎

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Original file line numberDiff line numberDiff line change
@@ -140,6 +140,14 @@ static constexpr uint32_t LC_RPATH = (0x1c | LC_REQ_DYLD);
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// The code signature which protects the preceding portion of the object file.
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// Must be the last contents in the object file. (linkedit_data_command)
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static constexpr uint32_t LC_CODE_SIGNATURE = 0x1d;
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// Information about encrypted segments for 32-bit targets. Must also be present
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// for programs with no encrypted segments that are uploaded to the App Store
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// so it can be updated appropriately.
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static constexpr uint32_t LC_ENCRYPTION_INFO = 0x21;
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// Information about encrypted segments for 64-bit targets. Must also be present
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// for programs with no encrypted segments that are uploaded to the App Store
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// so it can be updated appropriately.
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static constexpr uint32_t LC_ENCRYPTION_INFO_64 = 0x2c;
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// An arbitrary piece of data not specified by the Mach-O format. (note_command)
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static constexpr uint32_t LC_NOTE = 0x31;
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// The target platform and minimum and target OS versions for this object file.
@@ -743,6 +751,23 @@ static constexpr uint32_t RELOC_TYPE_ARM64_UNSIGNED = 0 << 28;
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// _before_ the target (UNSIGNED) entry that it is subtracted from.
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static constexpr uint32_t RELOC_TYPE_ARM64_SUBTRACTOR = 1 << 28;
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struct encryption_info_command {
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uint32_t cmd; // LC_ENCRYPTION_INFO
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uint32_t cmdsize;
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uint32_t cryptoff; // file offset of the encrypted segment(s)
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uint32_t cryptsize; // file size of the encrypted segment(s)
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uint32_t cryptid; // encryption cypher used (0 == not encrypted)
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};
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struct encryption_info_command_64 {
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uint32_t cmd; // LC_ENCRYPTION_INFO_64
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uint32_t cmdsize;
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uint32_t cryptoff; // file offset of the encrypted segment(s)
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uint32_t cryptsize; // file size of the encrypted segment(s)
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uint32_t cryptid; // encryption cypher used (0 == not encrypted)
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uint32_t pad; // padding to a multiple of 64 bits
769+
};
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746771
#pragma pack(pop)
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} // namespace mach_o

‎runtime/tests/vm/dart/use_macho_options_test.dart‎

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Original file line numberDiff line numberDiff line change
@@ -129,6 +129,7 @@ enum TestType {
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MinOSVersion,
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NoLinkerSignature,
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ReplaceInstallName,
132+
Encryptable,
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}
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134135
@pragma('vm:platform-const')
@@ -156,6 +157,7 @@ Future<void> checkCases(List<TestCase> testCases) async {
156157
checkRunPaths(c);
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checkBuildVersion(c);
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checkCodeSignature(c);
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checkEncryptionInfo(c);
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}
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// Unsigned snapshots are not runnable.
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final runnableCases = testCases
@@ -329,6 +331,21 @@ void checkCodeSignature(TestCase testCase) {
329331
}
330332
}
331333

334+
void checkEncryptionInfo(TestCase testCase) {
335+
final encryptionInfoCommands = testCase.snapshot.commands
336+
.whereType<macho.EncryptionInfoCommand>();
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if (testCase.type == TestType.Encryptable) {
338+
Expect.equals(1, encryptionInfoCommands.length);
339+
final cmd = encryptionInfoCommands.singleOrNull;
340+
if (cmd != null) {
341+
// gen_snapshot doesn't encrypt any segments.
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Expect.equals(0, cmd.cryptId);
343+
}
344+
} else {
345+
Expect.isEmpty(encryptionInfoCommands);
346+
}
347+
}
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void checkBuildVersion(TestCase testCase) {
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final buildVersion = testCase.snapshot
334351
.commandsWhereType<macho.BuildVersionCommand>()

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