SecStaticCode.cpp   [plain text]

/*
 * Copyright (c) 2006-2007,2011-2015 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
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 */

//
// SecStaticCode - API frame for SecStaticCode objects
//
#include "cs.h"
#include "StaticCode.h"
#include <security_utilities/cfmunge.h>
#include <security_utilities/logging.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, kSecCSForceOnlineNotarizationCheck);
	CodeSigning::Required(staticCodeRef) = (new SecStaticCode(DiskRep::bestGuess(cfString(path).c_str()), flags))->handle();

	END_CSAPI
}

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

OSStatus SecStaticCodeCreateWithPathAndAttributes(CFURLRef path, SecCSFlags flags, CFDictionaryRef attributes,
	SecStaticCodeRef *staticCodeRef)
{
	BEGIN_CSAPI

	checkFlags(flags, kSecCSForceOnlineNotarizationCheck);
	DiskRep::Context ctx;
	std::string version; // holds memory placed into ctx
	if (attributes) {
		std::string archName;
		int archNumber, subarchNumber, offset;
		if (cfscan(attributes, "{%O=%d}", kSecCodeAttributeUniversalFileOffset, &offset)) {
			ctx.offset = offset;
		} else 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), flags))->handle();

	END_CSAPI
}


//
// Check static validity of a StaticCode
//
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,
		  kSecCSReportProgress
		| kSecCSCheckAllArchitectures
		| kSecCSDoNotValidateExecutable
		| kSecCSDoNotValidateResources
		| kSecCSConsiderExpiration
		| kSecCSEnforceRevocationChecks
		| kSecCSNoNetworkAccess
		| kSecCSCheckNestedCode
		| kSecCSStrictValidate
		| kSecCSRestrictSidebandData
		| kSecCSCheckGatekeeperArchitectures
		| kSecCSRestrictSymlinks
		| kSecCSRestrictToAppLike
        | kSecCSUseSoftwareSigningCert
	    | kSecCSValidatePEH
		| kSecCSSingleThreaded
	);

	if (errors)
		flags |= kSecCSFullReport;	// internal-use flag

	SecPointer<SecStaticCode> code = SecStaticCode::requiredStatic(staticCodeRef);
	code->setValidationFlags(flags);
	const SecRequirement *req = SecRequirement::optional(requirementRef);
	DTRACK(CODESIGN_EVAL_STATIC, code, (char*)code->mainExecutablePath().c_str());
	code->staticValidate(flags, req);

#if TARGET_OS_IPHONE
    // Everything checked out correctly but we need to make sure that when
    // we validated the code directory, we trusted the signer.  We defer this
    // until now because the caller may still trust the signer via a
    // provisioning profile so if we prematurely throw an error when validating
    // the directory, we potentially skip resource validation even though the
    // caller will go on to trust the signature
    // <rdar://problem/6075501> Applications that are validated against a provisioning profile do not have their resources checked
    if (code->trustedSigningCertChain() == false) {
        return CSError::cfError(errors, errSecCSSignatureUntrusted);
    }
#endif


	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->copyCanonicalPath();

	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);

	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)) {
		if (code->isDetached()) {
			// Detached signatures need to attach their code directory from memory.
			fsignatures args = { static_cast<off_t>(code->diskRep()->signingBase()), (void *)cd, cd->length() };
			UnixError::check(::fcntl(code->diskRep()->fd(), F_ADDSIGS, &args));
		} else {
			// All other signatures can simply point to the signature in the main executable.
			Universal *execImage = code->diskRep()->mainExecutableImage();
			if (execImage == NULL) {
				MacOSError::throwMe(errSecCSNoMainExecutable);
			}

			auto_ptr<MachO> arch(execImage->architecture());
			if (arch.get() == NULL) {
				MacOSError::throwMe(errSecCSNoMainExecutable);
			}

			size_t signatureOffset = arch->signingOffset();
			size_t signatureLength = arch->signingLength();
			if (signatureOffset == 0) {
				MacOSError::throwMe(errSecCSUnsigned);
			}

			fsignatures args = {
				static_cast<off_t>(code->diskRep()->signingBase()),
				(void *)signatureOffset,
				signatureLength,
			};
			UnixError::check(::fcntl(code->diskRep()->fd(), F_ADDFILESIGS, &args));
		}
	} else {
		MacOSError::throwMe(errSecCSUnsigned);
	}

	END_CSAPI
}


//
// Attach a callback block to a code object
//
OSStatus SecStaticCodeSetCallback(SecStaticCodeRef codeRef, SecCSFlags flags, SecCodeCallback *old, SecCodeCallback monitor)
{
	BEGIN_CSAPI

	checkFlags(flags);
	SecStaticCode *code = SecStaticCode::requiredStatic(codeRef);
	if (old)
		*old = code->monitor();
	code->setMonitor(monitor);

	END_CSAPI
}


OSStatus SecStaticCodeSetValidationConditions(SecStaticCodeRef codeRef, CFDictionaryRef conditions)
{
	BEGIN_CSAPI

	checkFlags(0);
	SecStaticCode *code = SecStaticCode::requiredStatic(codeRef);
	code->setValidationModifiers(conditions);

	END_CSAPI
}


//
// Set cancellation flag on a static code object.
//
OSStatus SecStaticCodeCancelValidation(SecStaticCodeRef codeRef, SecCSFlags flags)
{
	BEGIN_CSAPI

	checkFlags(0);
	SecStaticCode *code = SecStaticCode::requiredStatic(codeRef);
	code->cancelValidation();

	END_CSAPI
}


//
// Retrieve a component object for a special slot directly.
//
CFDataRef SecCodeCopyComponent(SecCodeRef codeRef, int slot, CFDataRef hash)
{
	BEGIN_CSAPI
	
	SecStaticCode* code = SecStaticCode::requiredStatic(codeRef);
	return code->copyComponent(slot, hash);
	
	END_CSAPI1(NULL)
}


//
// Validate a single plain file's resource seal against a memory copy.
// This will fail for any other file type (symlink, directory, nested code, etc. etc.)
//
OSStatus SecCodeValidateFileResource(SecStaticCodeRef codeRef, CFStringRef relativePath, CFDataRef fileData, SecCSFlags flags)
{
    BEGIN_CSAPI
    
    checkFlags(0);
    if (fileData == NULL)
        MacOSError::throwMe(errSecCSObjectRequired);
    SecStaticCode *code = SecStaticCode::requiredStatic(codeRef);
    code->validatePlainMemoryResource(cfString(relativePath), fileData, flags);
    
    END_CSAPI
    
}