SecStaticCode.cpp   [plain text]


/*
 * Copyright (c) 2006-2007 Apple Inc. All Rights Reserved.
 * 
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

//
// SecStaticCode - API frame for SecStaticCode objects
//
#include "cs.h"
#include "StaticCode.h"
#include <security_utilities/cfmunge.h>
#include <fcntl.h>
#include <dirent.h>

using namespace CodeSigning;


//
// CF-standard type code function
//
CFTypeID SecStaticCodeGetTypeID(void)
{
	BEGIN_CSAPI
	return gCFObjects().StaticCode.typeID;
    END_CSAPI1(_kCFRuntimeNotATypeID)
}


//
// Create an StaticCode directly from disk path.
//
OSStatus SecStaticCodeCreateWithPath(CFURLRef path, SecCSFlags flags, SecStaticCodeRef *staticCodeRef)
{
	BEGIN_CSAPI
	
	checkFlags(flags);
	CodeSigning::Required(staticCodeRef) = (new SecStaticCode(DiskRep::bestGuess(cfString(path).c_str())))->handle();

	END_CSAPI
}

const CFStringRef kSecCodeAttributeArchitecture =	CFSTR("architecture");
const CFStringRef kSecCodeAttributeSubarchitecture =CFSTR("subarchitecture");
const CFStringRef kSecCodeAttributeBundleVersion =	CFSTR("bundleversion");

OSStatus SecStaticCodeCreateWithPathAndAttributes(CFURLRef path, SecCSFlags flags, CFDictionaryRef attributes,
	SecStaticCodeRef *staticCodeRef)
{
	BEGIN_CSAPI
	
	checkFlags(flags);
	DiskRep::Context ctx;
	std::string version; // holds memory placed into ctx
	if (attributes) {
		std::string archName;
		int archNumber, subarchNumber;
		if (cfscan(attributes, "{%O=%s}", kSecCodeAttributeArchitecture, &archName)) {
			ctx.arch = Architecture(archName.c_str());
		} else if (cfscan(attributes, "{%O=%d,%O=%d}",
				kSecCodeAttributeArchitecture, &archNumber, kSecCodeAttributeSubarchitecture, &subarchNumber))
			ctx.arch = Architecture(archNumber, subarchNumber);
		else if (cfscan(attributes, "{%O=%d}", kSecCodeAttributeArchitecture, &archNumber))
			ctx.arch = Architecture(archNumber);
		if (cfscan(attributes, "{%O=%s}", kSecCodeAttributeBundleVersion, &version))
			ctx.version = version.c_str();
	}
	
	CodeSigning::Required(staticCodeRef) = (new SecStaticCode(DiskRep::bestGuess(cfString(path).c_str(), &ctx)))->handle();

	END_CSAPI
}


//
// Check static validity of a StaticCode
//
static void validate(SecStaticCode *code, const SecRequirement *req, SecCSFlags flags);
static void validateNested(string location, const SecRequirement *req, SecCSFlags flags, string exclude = "/");

static void validate(SecStaticCode *code, const SecRequirement *req, SecCSFlags flags)
{
	try {
		code->validateDirectory();
		if (!(flags & kSecCSDoNotValidateExecutable))
			code->validateExecutable();
		if (!(flags & kSecCSDoNotValidateResources))
			code->validateResources();
		if (req)
			code->validateRequirement(req->requirement(), errSecCSReqFailed);
		if (flags & kSecCSCheckNestedCode)
			if (CFURLRef baseUrl = code->resourceBase()) {
				// CFBundle has no orderly enumerator of these things, so this is somewhat ad-hoc.
				// (It should be augmented by information in ResourceDirectory.)
				string base = cfString(baseUrl) + "/";
				validateNested(base + "Frameworks", req, flags);
				validateNested(base + "SharedFrameworks", req, flags);
				validateNested(base + "PlugIns", req, flags);
				validateNested(base + "Plug-ins", req, flags);
				validateNested(base + "XPCServices", req, flags);
				validateNested(base + "MacOS", req, flags, code->mainExecutablePath());	// helpers
			}
	} catch (CSError &err) {
		if (Universal *fat = code->diskRep()->mainExecutableImage())	// Mach-O
			if (MachO *mach = fat->architecture()) {
				err.augment(kSecCFErrorArchitecture, CFTempString(mach->architecture().displayName()));
				delete mach;
			}
		throw;
	} catch (const MacOSError &err) {
		// add architecture information if we can get it
		if (Universal *fat = code->diskRep()->mainExecutableImage())
			if (MachO *mach = fat->architecture()) {
				CFTempString arch(mach->architecture().displayName());
				delete mach;
				CSError::throwMe(err.error, kSecCFErrorArchitecture, arch);
			}
		// else just pass it on
		throw;
	}
}

static void validateNested(string location, const SecRequirement *req, SecCSFlags flags, string exclude)
{
	DIR *dir = opendir(location.c_str());
	if (dir == 0) {
		if (errno == ENOENT)	// nothing there (okay)
			return;
		UnixError::throwMe();
	}
	while (struct dirent *dp = readdir(dir)) {
		switch (dp->d_type) {
		case DT_REG:
		case DT_LNK:
		case DT_DIR:
			break;
		default:
			continue;
		}
		if (dp->d_name[0] == '.')
			continue;
		string path = location + "/" + dp->d_name;
		if (path == exclude)	// main executable; skip
			continue;
		try {
			SecPointer<SecStaticCode> code = new SecStaticCode(DiskRep::bestGuess(path));
			validate(code, req, flags);
		} catch (CSError &err) {
			err.augment(kSecCFErrorPath, CFTempURL(path));
			throw;
		}
	}
	closedir(dir);
}


OSStatus SecStaticCodeCheckValidity(SecStaticCodeRef staticCodeRef, SecCSFlags flags,
	SecRequirementRef requirementRef)
{
	return SecStaticCodeCheckValidityWithErrors(staticCodeRef, flags, requirementRef, NULL);
}

OSStatus SecStaticCodeCheckValidityWithErrors(SecStaticCodeRef staticCodeRef, SecCSFlags flags,
	SecRequirementRef requirementRef, CFErrorRef *errors)
{
	BEGIN_CSAPI
	
	checkFlags(flags,
		  kSecCSCheckAllArchitectures
		| kSecCSDoNotValidateExecutable
		| kSecCSDoNotValidateResources
		| kSecCSConsiderExpiration
		| kSecCSCheckNestedCode);

	SecPointer<SecStaticCode> code = SecStaticCode::requiredStatic(staticCodeRef);
	const SecRequirement *req = SecRequirement::optional(requirementRef);
	DTRACK(CODESIGN_EVAL_STATIC, code, (char*)code->mainExecutablePath().c_str());
	if (flags & kSecCSCheckAllArchitectures) {
		SecStaticCode::AllArchitectures archs(code);
		while (SecPointer<SecStaticCode> scode = archs())
			validate(scode, req, flags);
	} else
		validate(code, req, flags);

	END_CSAPI_ERRORS
}


//
// ====================================================================================
//
// The following API functions are called SecCode* but accept both SecCodeRef and
// SecStaticCodeRef arguments, operating on the implied SecStaticCodeRef as appropriate.
// Hence they're here, rather than in SecCode.cpp.
//


//
// Retrieve location information for an StaticCode.
//
OSStatus SecCodeCopyPath(SecStaticCodeRef staticCodeRef, SecCSFlags flags, CFURLRef *path)
{
	BEGIN_CSAPI
	
	checkFlags(flags);
	SecPointer<SecStaticCode> staticCode = SecStaticCode::requiredStatic(staticCodeRef);
	CodeSigning::Required(path) = staticCode->canonicalPath();

	END_CSAPI
}


//
// Fetch or make up a designated requirement
//
OSStatus SecCodeCopyDesignatedRequirement(SecStaticCodeRef staticCodeRef, SecCSFlags flags,
	SecRequirementRef *requirementRef)
{
	BEGIN_CSAPI
	
	checkFlags(flags);
	const Requirement *req =
		SecStaticCode::requiredStatic(staticCodeRef)->designatedRequirement();
	CodeSigning::Required(requirementRef) = (new SecRequirement(req))->handle();

	END_CSAPI
}


//
// Fetch a particular internal requirement, if present
//
OSStatus SecCodeCopyInternalRequirement(SecStaticCodeRef staticCodeRef, SecRequirementType type,
	SecCSFlags flags, SecRequirementRef *requirementRef)
{
	BEGIN_CSAPI
	
	checkFlags(flags);
	const Requirement *req =
		SecStaticCode::requiredStatic(staticCodeRef)->internalRequirement(type);
	CodeSigning::Required(requirementRef) = req ? (new SecRequirement(req))->handle() : NULL;

	END_CSAPI
}


//
// Record for future use a detached code signature.
//
OSStatus SecCodeSetDetachedSignature(SecStaticCodeRef codeRef, CFDataRef signature,
	SecCSFlags flags)
{
	BEGIN_CSAPI
	
	checkFlags(flags);
	SecPointer<SecStaticCode> code = SecStaticCode::requiredStatic(codeRef);

	if (signature)
		CFRetain(signature);	// own a reference...
	code->detachedSignature(signature); // ... and pass it to the code
	code->resetValidity();

	END_CSAPI
}


//
// Attach a code signature to a kernel memory mapping for page-in validation.
//
OSStatus SecCodeMapMemory(SecStaticCodeRef codeRef, SecCSFlags flags)
{
	BEGIN_CSAPI
	
	checkFlags(flags);
	SecPointer<SecStaticCode> code = SecStaticCode::requiredStatic(codeRef);
	if (const CodeDirectory *cd = code->codeDirectory(false)) {
		fsignatures args = { code->diskRep()->signingBase(), (void *)cd, cd->length() };
		UnixError::check(::fcntl(code->diskRep()->fd(), F_ADDSIGS, &args));
	} else
		MacOSError::throwMe(errSecCSUnsigned);

	END_CSAPI
}