electron/shell/common/mac/codesign_util.cc

116 lines
4.6 KiB
C++

// Copyright 2023 Microsoft, Inc.
// Copyright 2013 The Chromium Authors
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#include "shell/common/mac/codesign_util.h"
#include <optional>
#include "base/apple/foundation_util.h"
#include "base/apple/osstatus_logging.h"
#include "base/apple/scoped_cftyperef.h"
#include <CoreFoundation/CoreFoundation.h>
#include <Security/Security.h>
namespace electron {
std::optional<bool> IsUnsignedOrAdHocSigned(SecCodeRef code) {
base::apple::ScopedCFTypeRef<SecStaticCodeRef> static_code;
OSStatus status = SecCodeCopyStaticCode(code, kSecCSDefaultFlags,
static_code.InitializeInto());
if (status == errSecCSUnsigned) {
return true;
}
if (status != errSecSuccess) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopyStaticCode";
return std::optional<bool>();
}
// Copy the signing info from the SecStaticCodeRef.
base::apple::ScopedCFTypeRef<CFDictionaryRef> signing_info;
status =
SecCodeCopySigningInformation(static_code.get(), kSecCSSigningInformation,
signing_info.InitializeInto());
if (status != errSecSuccess) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopySigningInformation";
return std::optional<bool>();
}
// Look up the code signing flags. If the flags are absent treat this as
// unsigned. This decision is consistent with the StaticCode source:
// https://github.com/apple-oss-distributions/Security/blob/Security-60157.40.30.0.1/OSX/libsecurity_codesigning/lib/StaticCode.cpp#L2270
CFNumberRef signing_info_flags =
base::apple::GetValueFromDictionary<CFNumberRef>(signing_info.get(),
kSecCodeInfoFlags);
if (!signing_info_flags) {
return true;
}
// Using a long long to extract the value from the CFNumberRef to be
// consistent with how it was packed by Security.framework.
// https://github.com/apple-oss-distributions/Security/blob/Security-60157.40.30.0.1/OSX/libsecurity_utilities/lib/cfutilities.h#L262
long long flags;
if (!CFNumberGetValue(signing_info_flags, kCFNumberLongLongType, &flags)) {
LOG(ERROR) << "CFNumberGetValue";
return std::optional<bool>();
}
if (static_cast<uint32_t>(flags) & kSecCodeSignatureAdhoc) {
return true;
}
return false;
}
bool ProcessSignatureIsSameWithCurrentApp(pid_t pid) {
// Get and check the code signature of current app.
base::apple::ScopedCFTypeRef<SecCodeRef> self_code;
OSStatus status =
SecCodeCopySelf(kSecCSDefaultFlags, self_code.InitializeInto());
if (status != errSecSuccess) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopyGuestWithAttributes";
return false;
}
std::optional<bool> not_signed = IsUnsignedOrAdHocSigned(self_code.get());
if (!not_signed.has_value()) {
// Error happened.
return false;
}
if (not_signed.value()) {
// Current app is not signed.
return true;
}
// Get the code signature of process.
base::apple::ScopedCFTypeRef<CFNumberRef> process_cf(
CFNumberCreate(nullptr, kCFNumberIntType, &pid));
const void* attribute_keys[] = {kSecGuestAttributePid};
const void* attribute_values[] = {process_cf.get()};
base::apple::ScopedCFTypeRef<CFDictionaryRef> attributes(CFDictionaryCreate(
nullptr, attribute_keys, attribute_values, std::size(attribute_keys),
&kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks));
base::apple::ScopedCFTypeRef<SecCodeRef> process_code;
status = SecCodeCopyGuestWithAttributes(nullptr, attributes.get(),
kSecCSDefaultFlags,
process_code.InitializeInto());
if (status != errSecSuccess) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopyGuestWithAttributes";
return false;
}
// Get the requirement of current app's code signature.
base::apple::ScopedCFTypeRef<SecRequirementRef> self_requirement;
status = SecCodeCopyDesignatedRequirement(self_code.get(), kSecCSDefaultFlags,
self_requirement.InitializeInto());
if (status != errSecSuccess) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopyDesignatedRequirement";
return false;
}
DCHECK(self_requirement.get());
// Check whether the process meets the signature requirement of current app.
status = SecCodeCheckValidity(process_code.get(), kSecCSDefaultFlags,
self_requirement.get());
if (status != errSecSuccess && status != errSecCSReqFailed) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCheckValidity";
return false;
}
return status == errSecSuccess;
}
} // namespace electron