--- /dev/null
+/*
+ * Copyright (c) 2006-2012 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@
+ */
+
+//
+// StaticCode - SecStaticCode API objects
+//
+#include "StaticCode.h"
+#include "Code.h"
+#include "reqmaker.h"
+#include "drmaker.h"
+#include "reqdumper.h"
+#include "sigblob.h"
+#include "resources.h"
+#include "renum.h"
+#include "detachedrep.h"
+#include "csdatabase.h"
+#include "csutilities.h"
+#include <CoreFoundation/CFURLAccess.h>
+#include <Security/SecPolicyPriv.h>
+#include <Security/SecTrustPriv.h>
+#include <Security/SecCertificatePriv.h>
+#include <Security/CMSPrivate.h>
+#include <Security/SecCmsContentInfo.h>
+#include <Security/SecCmsSignerInfo.h>
+#include <Security/SecCmsSignedData.h>
+#include <Security/cssmapplePriv.h>
+#include <security_utilities/unix++.h>
+#include <security_utilities/cfmunge.h>
+#include <Security/CMSDecoder.h>
+
+
+namespace Security {
+namespace CodeSigning {
+
+using namespace UnixPlusPlus;
+
+
+//
+// Construct a SecStaticCode object given a disk representation object
+//
+SecStaticCode::SecStaticCode(DiskRep *rep)
+ : mRep(rep),
+ mValidated(false), mExecutableValidated(false), mResourcesValidated(false), mResourcesValidContext(NULL),
+ mDesignatedReq(NULL), mGotResourceBase(false), mEvalDetails(NULL)
+{
+ CODESIGN_STATIC_CREATE(this, rep);
+ checkForSystemSignature();
+}
+
+
+//
+// Clean up a SecStaticCode object
+//
+SecStaticCode::~SecStaticCode() throw()
+try {
+ ::free(const_cast<Requirement *>(mDesignatedReq));
+ if (mResourcesValidContext)
+ delete mResourcesValidContext;
+} catch (...) {
+ return;
+}
+
+
+//
+// CF-level comparison of SecStaticCode objects compares CodeDirectory hashes if signed,
+// and falls back on comparing canonical paths if (both are) not.
+//
+bool SecStaticCode::equal(SecCFObject &secOther)
+{
+ SecStaticCode *other = static_cast<SecStaticCode *>(&secOther);
+ CFDataRef mine = this->cdHash();
+ CFDataRef his = other->cdHash();
+ if (mine || his)
+ return mine && his && CFEqual(mine, his);
+ else
+ return CFEqual(this->canonicalPath(), other->canonicalPath());
+}
+
+CFHashCode SecStaticCode::hash()
+{
+ if (CFDataRef h = this->cdHash())
+ return CFHash(h);
+ else
+ return CFHash(this->canonicalPath());
+}
+
+
+//
+// Attach a detached signature.
+//
+void SecStaticCode::detachedSignature(CFDataRef sigData)
+{
+ if (sigData) {
+ mRep = new DetachedRep(sigData, mRep->base(), "explicit detached");
+ CODESIGN_STATIC_ATTACH_EXPLICIT(this, mRep);
+ } else {
+ mRep = mRep->base();
+ CODESIGN_STATIC_ATTACH_EXPLICIT(this, NULL);
+ }
+}
+
+
+//
+// Consult the system detached signature database to see if it contains
+// a detached signature for this StaticCode. If it does, fetch and attach it.
+// We do this only if the code has no signature already attached.
+//
+void SecStaticCode::checkForSystemSignature()
+{
+ if (!this->isSigned())
+ try {
+ if (RefPointer<DiskRep> dsig = signatureDatabase().findCode(mRep)) {
+ CODESIGN_STATIC_ATTACH_SYSTEM(this, dsig);
+ mRep = dsig;
+ }
+ } catch (...) {
+ }
+}
+
+
+//
+// Return a descriptive string identifying the source of the code signature
+//
+string SecStaticCode::signatureSource()
+{
+ if (!isSigned())
+ return "unsigned";
+ if (DetachedRep *rep = dynamic_cast<DetachedRep *>(mRep.get()))
+ return rep->source();
+ return "embedded";
+}
+
+
+//
+// Do ::required, but convert incoming SecCodeRefs to their SecStaticCodeRefs
+// (if possible).
+//
+SecStaticCode *SecStaticCode::requiredStatic(SecStaticCodeRef ref)
+{
+ SecCFObject *object = SecCFObject::required(ref, errSecCSInvalidObjectRef);
+ if (SecStaticCode *scode = dynamic_cast<SecStaticCode *>(object))
+ return scode;
+ else if (SecCode *code = dynamic_cast<SecCode *>(object))
+ return code->staticCode();
+ else // neither (a SecSomethingElse)
+ MacOSError::throwMe(errSecCSInvalidObjectRef);
+}
+
+SecCode *SecStaticCode::optionalDynamic(SecStaticCodeRef ref)
+{
+ SecCFObject *object = SecCFObject::required(ref, errSecCSInvalidObjectRef);
+ if (dynamic_cast<SecStaticCode *>(object))
+ return NULL;
+ else if (SecCode *code = dynamic_cast<SecCode *>(object))
+ return code;
+ else // neither (a SecSomethingElse)
+ MacOSError::throwMe(errSecCSInvalidObjectRef);
+}
+
+
+//
+// Void all cached validity data.
+//
+// We also throw out cached components, because the new signature data may have
+// a different idea of what components should be present. We could reconcile the
+// cached data instead, if performance seems to be impacted.
+//
+void SecStaticCode::resetValidity()
+{
+ CODESIGN_EVAL_STATIC_RESET(this);
+ mValidated = false;
+ mExecutableValidated = false;
+ mResourcesValidated = false;
+ if (mResourcesValidContext) {
+ delete mResourcesValidContext;
+ mResourcesValidContext = NULL;
+ }
+ mDir = NULL;
+ mSignature = NULL;
+ for (unsigned n = 0; n < cdSlotCount; n++)
+ mCache[n] = NULL;
+ mInfoDict = NULL;
+ mEntitlements = NULL;
+ mResourceDict = NULL;
+ mDesignatedReq = NULL;
+ mGotResourceBase = false;
+ mTrust = NULL;
+ mCertChain = NULL;
+ mEvalDetails = NULL;
+ mRep->flush();
+
+ // we may just have updated the system database, so check again
+ checkForSystemSignature();
+}
+
+
+//
+// Retrieve a sealed component by special slot index.
+// If the CodeDirectory has already been validated, validate against that.
+// Otherwise, retrieve the component without validation (but cache it). Validation
+// will go through the cache and validate all cached components.
+//
+CFDataRef SecStaticCode::component(CodeDirectory::SpecialSlot slot, OSStatus fail /* = errSecCSSignatureFailed */)
+{
+ assert(slot <= cdSlotMax);
+
+ CFRef<CFDataRef> &cache = mCache[slot];
+ if (!cache) {
+ if (CFRef<CFDataRef> data = mRep->component(slot)) {
+ if (validated()) // if the directory has been validated...
+ if (!codeDirectory()->validateSlot(CFDataGetBytePtr(data), // ... and it's no good
+ CFDataGetLength(data), -slot))
+ MacOSError::throwMe(fail); // ... then bail
+ cache = data; // it's okay, cache it
+ } else { // absent, mark so
+ if (validated()) // if directory has been validated...
+ if (codeDirectory()->slotIsPresent(-slot)) // ... and the slot is NOT missing
+ MacOSError::throwMe(fail); // was supposed to be there
+ cache = CFDataRef(kCFNull); // white lie
+ }
+ }
+ return (cache == CFDataRef(kCFNull)) ? NULL : cache.get();
+}
+
+
+//
+// Get the CodeDirectory.
+// Throws (if check==true) or returns NULL (check==false) if there is none.
+// Always throws if the CodeDirectory exists but is invalid.
+// NEVER validates against the signature.
+//
+const CodeDirectory *SecStaticCode::codeDirectory(bool check /* = true */)
+{
+ if (!mDir) {
+ if (mDir.take(mRep->codeDirectory())) {
+ const CodeDirectory *dir = reinterpret_cast<const CodeDirectory *>(CFDataGetBytePtr(mDir));
+ dir->checkIntegrity();
+ }
+ }
+ if (mDir)
+ return reinterpret_cast<const CodeDirectory *>(CFDataGetBytePtr(mDir));
+ if (check)
+ MacOSError::throwMe(errSecCSUnsigned);
+ return NULL;
+}
+
+
+//
+// Get the hash of the CodeDirectory.
+// Returns NULL if there is none.
+//
+CFDataRef SecStaticCode::cdHash()
+{
+ if (!mCDHash) {
+ if (const CodeDirectory *cd = codeDirectory(false)) {
+ SHA1 hash;
+ hash(cd, cd->length());
+ SHA1::Digest digest;
+ hash.finish(digest);
+ mCDHash.take(makeCFData(digest, sizeof(digest)));
+ CODESIGN_STATIC_CDHASH(this, digest, sizeof(digest));
+ }
+ }
+ return mCDHash;
+}
+
+
+//
+// Return the CMS signature blob; NULL if none found.
+//
+CFDataRef SecStaticCode::signature()
+{
+ if (!mSignature)
+ mSignature.take(mRep->signature());
+ if (mSignature)
+ return mSignature;
+ MacOSError::throwMe(errSecCSUnsigned);
+}
+
+
+//
+// Verify the signature on the CodeDirectory.
+// If this succeeds (doesn't throw), the CodeDirectory is statically trustworthy.
+// Any outcome (successful or not) is cached for the lifetime of the StaticCode.
+//
+void SecStaticCode::validateDirectory()
+{
+ // echo previous outcome, if any
+ if (!validated())
+ try {
+ // perform validation (or die trying)
+ CODESIGN_EVAL_STATIC_DIRECTORY(this);
+ mValidationExpired = verifySignature();
+ component(cdInfoSlot, errSecCSInfoPlistFailed); // force load of Info Dictionary (if any)
+ for (CodeDirectory::SpecialSlot slot = codeDirectory()->maxSpecialSlot(); slot >= 1; --slot)
+ if (mCache[slot]) // if we already loaded that resource...
+ validateComponent(slot); // ... then check it now
+ mValidated = true; // we've done the deed...
+ mValidationResult = noErr; // ... and it was good
+ } catch (const CommonError &err) {
+ mValidated = true;
+ mValidationResult = err.osStatus();
+ throw;
+ } catch (...) {
+ secdebug("staticCode", "%p validation threw non-common exception", this);
+ mValidated = true;
+ mValidationResult = errSecCSInternalError;
+ throw;
+ }
+ assert(validated());
+ if (mValidationResult == noErr) {
+ if (mValidationExpired)
+ if ((apiFlags() & kSecCSConsiderExpiration)
+ || (codeDirectory()->flags & kSecCodeSignatureForceExpiration))
+ MacOSError::throwMe(CSSMERR_TP_CERT_EXPIRED);
+ } else
+ MacOSError::throwMe(mValidationResult);
+}
+
+
+//
+// Load and validate the CodeDirectory and all components *except* those related to the resource envelope.
+// Those latter components are checked by validateResources().
+//
+void SecStaticCode::validateNonResourceComponents()
+{
+ this->validateDirectory();
+ for (CodeDirectory::SpecialSlot slot = codeDirectory()->maxSpecialSlot(); slot >= 1; --slot)
+ switch (slot) {
+ case cdResourceDirSlot: // validated by validateResources
+ break;
+ default:
+ this->component(slot); // loads and validates
+ break;
+ }
+}
+
+
+//
+// Get the (signed) signing date from the code signature.
+// Sadly, we need to validate the signature to get the date (as a side benefit).
+// This means that you can't get the signing time for invalidly signed code.
+//
+// We could run the decoder "almost to" verification to avoid this, but there seems
+// little practical point to such a duplication of effort.
+//
+CFAbsoluteTime SecStaticCode::signingTime()
+{
+ validateDirectory();
+ return mSigningTime;
+}
+
+CFAbsoluteTime SecStaticCode::signingTimestamp()
+{
+ validateDirectory();
+ return mSigningTimestamp;
+}
+
+
+//
+// Verify the CMS signature on the CodeDirectory.
+// This performs the cryptographic tango. It returns if the signature is valid,
+// or throws if it is not. As a side effect, a successful return sets up the
+// cached certificate chain for future use.
+// Returns true if the signature is expired (the X.509 sense), false if it's not.
+//
+bool SecStaticCode::verifySignature()
+{
+ // ad-hoc signed code is considered validly signed by definition
+ if (flag(kSecCodeSignatureAdhoc)) {
+ CODESIGN_EVAL_STATIC_SIGNATURE_ADHOC(this);
+ return false;
+ }
+
+ DTRACK(CODESIGN_EVAL_STATIC_SIGNATURE, this, (char*)this->mainExecutablePath().c_str());
+
+ // decode CMS and extract SecTrust for verification
+ CFRef<CMSDecoderRef> cms;
+ MacOSError::check(CMSDecoderCreate(&cms.aref())); // create decoder
+ CFDataRef sig = this->signature();
+ MacOSError::check(CMSDecoderUpdateMessage(cms, CFDataGetBytePtr(sig), CFDataGetLength(sig)));
+ this->codeDirectory(); // load CodeDirectory (sets mDir)
+ MacOSError::check(CMSDecoderSetDetachedContent(cms, mDir));
+ MacOSError::check(CMSDecoderFinalizeMessage(cms));
+ MacOSError::check(CMSDecoderSetSearchKeychain(cms, cfEmptyArray()));
+ CFRef<CFTypeRef> policy = verificationPolicy(apiFlags());
+ CMSSignerStatus status;
+ MacOSError::check(CMSDecoderCopySignerStatus(cms, 0, policy,
+ false, &status, &mTrust.aref(), NULL));
+ if (status != kCMSSignerValid)
+ MacOSError::throwMe(errSecCSSignatureFailed);
+
+ // internal signing time (as specified by the signer; optional)
+ mSigningTime = 0; // "not present" marker (nobody could code sign on Jan 1, 2001 :-)
+ switch (OSStatus rc = CMSDecoderCopySignerSigningTime(cms, 0, &mSigningTime)) {
+ case noErr:
+ case errSecSigningTimeMissing:
+ break;
+ default:
+ MacOSError::throwMe(rc);
+ }
+
+ // certified signing time (as specified by a TSA; optional)
+ mSigningTimestamp = 0;
+ switch (OSStatus rc = CMSDecoderCopySignerTimestamp(cms, 0, &mSigningTimestamp)) {
+ case noErr:
+ case errSecTimestampMissing:
+ break;
+ default:
+ MacOSError::throwMe(rc);
+ }
+
+ // set up the environment for SecTrust
+ MacOSError::check(SecTrustSetAnchorCertificates(mTrust, cfEmptyArray())); // no anchors
+ MacOSError::check(SecTrustSetKeychains(mTrust, cfEmptyArray())); // no keychains
+ CSSM_APPLE_TP_ACTION_DATA actionData = {
+ CSSM_APPLE_TP_ACTION_VERSION, // version of data structure
+ CSSM_TP_ACTION_IMPLICIT_ANCHORS // action flags
+ };
+
+ for (;;) { // at most twice
+ MacOSError::check(SecTrustSetParameters(mTrust,
+ CSSM_TP_ACTION_DEFAULT, CFTempData(&actionData, sizeof(actionData))));
+
+ // evaluate trust and extract results
+ SecTrustResultType trustResult;
+ MacOSError::check(SecTrustEvaluate(mTrust, &trustResult));
+ MacOSError::check(SecTrustGetResult(mTrust, &trustResult, &mCertChain.aref(), &mEvalDetails));
+ CODESIGN_EVAL_STATIC_SIGNATURE_RESULT(this, trustResult, mCertChain ? CFArrayGetCount(mCertChain) : 0);
+ switch (trustResult) {
+ case kSecTrustResultProceed:
+ case kSecTrustResultUnspecified:
+ break; // success
+ case kSecTrustResultDeny:
+ MacOSError::throwMe(CSSMERR_APPLETP_TRUST_SETTING_DENY); // user reject
+ case kSecTrustResultInvalid:
+ assert(false); // should never happen
+ MacOSError::throwMe(CSSMERR_TP_NOT_TRUSTED);
+ default:
+ {
+ OSStatus result;
+ MacOSError::check(SecTrustGetCssmResultCode(mTrust, &result));
+ // if we have a valid timestamp, CMS validates against (that) signing time and all is well.
+ // If we don't have one, may validate against *now*, and must be able to tolerate expiration.
+ if (mSigningTimestamp == 0) // no timestamp available
+ if (((result == CSSMERR_TP_CERT_EXPIRED) || (result == CSSMERR_TP_CERT_NOT_VALID_YET))
+ && !(actionData.ActionFlags & CSSM_TP_ACTION_ALLOW_EXPIRED)) {
+ CODESIGN_EVAL_STATIC_SIGNATURE_EXPIRED(this);
+ actionData.ActionFlags |= CSSM_TP_ACTION_ALLOW_EXPIRED; // (this also allows postdated certs)
+ continue; // retry validation while tolerating expiration
+ }
+ MacOSError::throwMe(result);
+ }
+ }
+ return actionData.ActionFlags & CSSM_TP_ACTION_ALLOW_EXPIRED;
+ }
+}
+
+
+//
+// Return the TP policy used for signature verification.
+// This may be a simple SecPolicyRef or a CFArray of policies.
+// The caller owns the return value.
+//
+static SecPolicyRef makeCRLPolicy()
+{
+ CFRef<SecPolicyRef> policy;
+ MacOSError::check(SecPolicyCopy(CSSM_CERT_X_509v3, &CSSMOID_APPLE_TP_REVOCATION_CRL, &policy.aref()));
+ CSSM_APPLE_TP_CRL_OPTIONS options;
+ memset(&options, 0, sizeof(options));
+ options.Version = CSSM_APPLE_TP_CRL_OPTS_VERSION;
+ options.CrlFlags = CSSM_TP_ACTION_FETCH_CRL_FROM_NET | CSSM_TP_ACTION_CRL_SUFFICIENT;
+ CSSM_DATA optData = { sizeof(options), (uint8 *)&options };
+ MacOSError::check(SecPolicySetValue(policy, &optData));
+ return policy.yield();
+}
+
+static SecPolicyRef makeOCSPPolicy()
+{
+ CFRef<SecPolicyRef> policy;
+ MacOSError::check(SecPolicyCopy(CSSM_CERT_X_509v3, &CSSMOID_APPLE_TP_REVOCATION_OCSP, &policy.aref()));
+ CSSM_APPLE_TP_OCSP_OPTIONS options;
+ memset(&options, 0, sizeof(options));
+ options.Version = CSSM_APPLE_TP_OCSP_OPTS_VERSION;
+ options.Flags = CSSM_TP_ACTION_OCSP_SUFFICIENT;
+ CSSM_DATA optData = { sizeof(options), (uint8 *)&options };
+ MacOSError::check(SecPolicySetValue(policy, &optData));
+ return policy.yield();
+}
+
+CFTypeRef SecStaticCode::verificationPolicy(SecCSFlags flags)
+{
+ CFRef<SecPolicyRef> core;
+ MacOSError::check(SecPolicyCopy(CSSM_CERT_X_509v3,
+ &CSSMOID_APPLE_TP_CODE_SIGNING, &core.aref()));
+ if (flags & kSecCSEnforceRevocationChecks) {
+ CFRef<SecPolicyRef> crl = makeCRLPolicy();
+ CFRef<SecPolicyRef> ocsp = makeOCSPPolicy();
+ return makeCFArray(3, core.get(), crl.get(), ocsp.get());
+ } else {
+ return core.yield();
+ }
+}
+
+
+//
+// Validate a particular sealed, cached resource against its (special) CodeDirectory slot.
+// The resource must already have been placed in the cache.
+// This does NOT perform basic validation.
+//
+void SecStaticCode::validateComponent(CodeDirectory::SpecialSlot slot, OSStatus fail /* = errSecCSSignatureFailed */)
+{
+ assert(slot <= cdSlotMax);
+ CFDataRef data = mCache[slot];
+ assert(data); // must be cached
+ if (data == CFDataRef(kCFNull)) {
+ if (codeDirectory()->slotIsPresent(-slot)) // was supposed to be there...
+ MacOSError::throwMe(fail); // ... and is missing
+ } else {
+ if (!codeDirectory()->validateSlot(CFDataGetBytePtr(data), CFDataGetLength(data), -slot))
+ MacOSError::throwMe(fail);
+ }
+}
+
+
+//
+// Perform static validation of the main executable.
+// This reads the main executable from disk and validates it against the
+// CodeDirectory code slot array.
+// Note that this is NOT an in-memory validation, and is thus potentially
+// subject to timing attacks.
+//
+void SecStaticCode::validateExecutable()
+{
+ if (!validatedExecutable()) {
+ try {
+ DTRACK(CODESIGN_EVAL_STATIC_EXECUTABLE, this,
+ (char*)this->mainExecutablePath().c_str(), codeDirectory()->nCodeSlots);
+ const CodeDirectory *cd = this->codeDirectory();
+ if (!cd)
+ MacOSError::throwMe(errSecCSUnsigned);
+ AutoFileDesc fd(mainExecutablePath(), O_RDONLY);
+ fd.fcntl(F_NOCACHE, true); // turn off page caching (one-pass)
+ if (Universal *fat = mRep->mainExecutableImage())
+ fd.seek(fat->archOffset());
+ size_t pageSize = cd->pageSize ? (1 << cd->pageSize) : 0;
+ size_t remaining = cd->codeLimit;
+ for (size_t slot = 0; slot < cd->nCodeSlots; ++slot) {
+ size_t size = min(remaining, pageSize);
+ if (!cd->validateSlot(fd, size, slot)) {
+ CODESIGN_EVAL_STATIC_EXECUTABLE_FAIL(this, slot);
+ MacOSError::throwMe(errSecCSSignatureFailed);
+ }
+ remaining -= size;
+ }
+ mExecutableValidated = true;
+ mExecutableValidResult = noErr;
+ } catch (const CommonError &err) {
+ mExecutableValidated = true;
+ mExecutableValidResult = err.osStatus();
+ throw;
+ } catch (...) {
+ secdebug("staticCode", "%p executable validation threw non-common exception", this);
+ mExecutableValidated = true;
+ mExecutableValidResult = errSecCSInternalError;
+ throw;
+ }
+ }
+ assert(validatedExecutable());
+ if (mExecutableValidResult != noErr)
+ MacOSError::throwMe(mExecutableValidResult);
+}
+
+
+//
+// Perform static validation of sealed resources.
+//
+// This performs a whole-code static resource scan and effectively
+// computes a concordance between what's on disk and what's in the ResourceDirectory.
+// Any unsanctioned difference causes an error.
+//
+void SecStaticCode::validateResources()
+{
+ if (!validatedResources()) {
+ try {
+ // sanity first
+ CFDictionaryRef sealedResources = resourceDictionary();
+ if (this->resourceBase()) // disk has resources
+ if (sealedResources)
+ /* go to work below */;
+ else
+ MacOSError::throwMe(errSecCSResourcesNotFound);
+ else // disk has no resources
+ if (sealedResources)
+ MacOSError::throwMe(errSecCSResourcesNotFound);
+ else
+ return; // no resources, not sealed - fine (no work)
+
+ // found resources, and they are sealed
+ CFDictionaryRef rules = cfget<CFDictionaryRef>(sealedResources, "rules");
+ CFDictionaryRef files = cfget<CFDictionaryRef>(sealedResources, "files");
+ DTRACK(CODESIGN_EVAL_STATIC_RESOURCES, this,
+ (char*)this->mainExecutablePath().c_str(), int(CFDictionaryGetCount(files)));
+
+ // make a shallow copy of the ResourceDirectory so we can "check off" what we find
+ CFRef<CFMutableDictionaryRef> resourceMap = makeCFMutableDictionary(files);
+
+ // scan through the resources on disk, checking each against the resourceDirectory
+ mResourcesValidContext = new CollectingContext(*this); // collect all failures in here
+ ResourceBuilder resources(cfString(this->resourceBase()), rules, codeDirectory()->hashType);
+ mRep->adjustResources(resources);
+ string path;
+ ResourceBuilder::Rule *rule;
+
+ while (resources.next(path, rule)) {
+ validateResource(path, *mResourcesValidContext);
+ CFDictionaryRemoveValue(resourceMap, CFTempString(path));
+ }
+
+ if (CFDictionaryGetCount(resourceMap) > 0) {
+ secdebug("staticCode", "%p sealed resource(s) not found in code", this);
+ CFDictionaryApplyFunction(resourceMap, SecStaticCode::checkOptionalResource, mResourcesValidContext);
+ }
+
+ // now check for any errors found in the reporting context
+ mResourcesValidated = true;
+ if (mResourcesValidContext->osStatus() != noErr)
+ mResourcesValidContext->throwMe();
+
+ } catch (const CommonError &err) {
+ mResourcesValidated = true;
+ mResourcesValidResult = err.osStatus();
+ throw;
+ } catch (...) {
+ secdebug("staticCode", "%p executable validation threw non-common exception", this);
+ mResourcesValidated = true;
+ mResourcesValidResult = errSecCSInternalError;
+ throw;
+ }
+ }
+ assert(validatedResources());
+ if (mResourcesValidResult)
+ MacOSError::throwMe(mResourcesValidResult);
+ if (mResourcesValidContext->osStatus() != noErr)
+ mResourcesValidContext->throwMe();
+}
+
+
+void SecStaticCode::checkOptionalResource(CFTypeRef key, CFTypeRef value, void *context)
+{
+ CollectingContext *ctx = static_cast<CollectingContext *>(context);
+ ResourceSeal seal(value);
+ if (!seal.optional()) {
+ if (key && CFGetTypeID(key) == CFStringGetTypeID()) {
+ ctx->reportProblem(errSecCSBadResource, kSecCFErrorResourceMissing,
+ CFTempURL(CFStringRef(key), false, ctx->code.resourceBase()));
+ } else {
+ ctx->reportProblem(errSecCSBadResource, kSecCFErrorResourceSeal, key);
+ }
+ }
+}
+
+
+//
+// Load, validate, cache, and return CFDictionary forms of sealed resources.
+//
+CFDictionaryRef SecStaticCode::infoDictionary()
+{
+ if (!mInfoDict) {
+ mInfoDict.take(getDictionary(cdInfoSlot, errSecCSInfoPlistFailed));
+ secdebug("staticCode", "%p loaded InfoDict %p", this, mInfoDict.get());
+ }
+ return mInfoDict;
+}
+
+CFDictionaryRef SecStaticCode::entitlements()
+{
+ if (!mEntitlements) {
+ validateDirectory();
+ if (CFDataRef entitlementData = component(cdEntitlementSlot)) {
+ validateComponent(cdEntitlementSlot);
+ const EntitlementBlob *blob = reinterpret_cast<const EntitlementBlob *>(CFDataGetBytePtr(entitlementData));
+ if (blob->validateBlob()) {
+ mEntitlements.take(blob->entitlements());
+ secdebug("staticCode", "%p loaded Entitlements %p", this, mEntitlements.get());
+ }
+ // we do not consider a different blob type to be an error. We think it's a new format we don't understand
+ }
+ }
+ return mEntitlements;
+}
+
+CFDictionaryRef SecStaticCode::resourceDictionary()
+{
+ if (mResourceDict) // cached
+ return mResourceDict;
+ if (CFRef<CFDictionaryRef> dict = getDictionary(cdResourceDirSlot, errSecCSSignatureFailed))
+ if (cfscan(dict, "{rules=%Dn,files=%Dn}")) {
+ secdebug("staticCode", "%p loaded ResourceDict %p",
+ this, mResourceDict.get());
+ return mResourceDict = dict;
+ }
+ // bad format
+ return NULL;
+}
+
+
+//
+// Load and cache the resource directory base.
+// Note that the base is optional for each DiskRep.
+//
+CFURLRef SecStaticCode::resourceBase()
+{
+ if (!mGotResourceBase) {
+ string base = mRep->resourcesRootPath();
+ if (!base.empty())
+ mResourceBase.take(makeCFURL(base, true));
+ mGotResourceBase = true;
+ }
+ return mResourceBase;
+}
+
+
+//
+// Load a component, validate it, convert it to a CFDictionary, and return that.
+// This will force load and validation, which means that it will perform basic
+// validation if it hasn't been done yet.
+//
+CFDictionaryRef SecStaticCode::getDictionary(CodeDirectory::SpecialSlot slot, OSStatus fail /* = errSecCSSignatureFailed */)
+{
+ validateDirectory();
+ if (CFDataRef infoData = component(slot, fail)) {
+ validateComponent(slot, fail);
+ if (CFDictionaryRef dict = makeCFDictionaryFrom(infoData))
+ return dict;
+ else
+ MacOSError::throwMe(errSecCSBadDictionaryFormat);
+ }
+ return NULL;
+}
+
+
+//
+// Load, validate, and return a sealed resource.
+// The resource data (loaded in to memory as a blob) is returned and becomes
+// the responsibility of the caller; it is NOT cached by SecStaticCode.
+//
+// A resource that is not sealed will not be returned, and an error will be thrown.
+// A missing resource will cause an error unless it's marked optional in the Directory.
+// Under no circumstances will a corrupt resource be returned.
+// NULL will only be returned for a resource that is neither sealed nor present
+// (or that is sealed, absent, and marked optional).
+// If the ResourceDictionary itself is not sealed, this function will always fail.
+//
+// There is currently no interface for partial retrieval of the resource data.
+// (Since the ResourceDirectory does not currently support segmentation, all the
+// data would have to be read anyway, but it could be read into a reusable buffer.)
+//
+CFDataRef SecStaticCode::resource(string path, ValidationContext &ctx)
+{
+ if (CFDictionaryRef rdict = resourceDictionary()) {
+ if (CFTypeRef file = cfget(rdict, "files.%s", path.c_str())) {
+ ResourceSeal seal = file;
+ if (!resourceBase()) // no resources in DiskRep
+ MacOSError::throwMe(errSecCSResourcesNotFound);
+ CFRef<CFURLRef> fullpath = makeCFURL(path, false, resourceBase());
+ if (CFRef<CFDataRef> data = cfLoadFile(fullpath)) {
+ MakeHash<CodeDirectory> hasher(this->codeDirectory());
+ hasher->update(CFDataGetBytePtr(data), CFDataGetLength(data));
+ if (hasher->verify(seal.hash()))
+ return data.yield(); // good
+ else
+ ctx.reportProblem(errSecCSBadResource, kSecCFErrorResourceAltered, fullpath); // altered
+ } else {
+ if (!seal.optional())
+ ctx.reportProblem(errSecCSBadResource, kSecCFErrorResourceMissing, fullpath); // was sealed but is now missing
+ else
+ return NULL; // validly missing
+ }
+ } else
+ ctx.reportProblem(errSecCSBadResource, kSecCFErrorResourceAdded, CFTempURL(path, false, resourceBase()));
+ return NULL;
+ } else
+ MacOSError::throwMe(errSecCSResourcesNotSealed);
+}
+
+CFDataRef SecStaticCode::resource(string path)
+{
+ ValidationContext ctx;
+ return resource(path, ctx);
+}
+
+
+void SecStaticCode::validateResource(string path, ValidationContext &ctx)
+{
+ if (CFDictionaryRef rdict = resourceDictionary()) {
+ if (CFTypeRef file = cfget(rdict, "files.%s", path.c_str())) {
+ ResourceSeal seal = file;
+ if (!resourceBase()) // no resources in DiskRep
+ MacOSError::throwMe(errSecCSResourcesNotFound);
+ CFRef<CFURLRef> fullpath = makeCFURL(path, false, resourceBase());
+ AutoFileDesc fd(cfString(fullpath), O_RDONLY, FileDesc::modeMissingOk); // open optional filee
+ if (fd) {
+ MakeHash<CodeDirectory> hasher(this->codeDirectory());
+ hashFileData(fd, hasher.get());
+ if (hasher->verify(seal.hash()))
+ return; // verify good
+ else
+ ctx.reportProblem(errSecCSBadResource, kSecCFErrorResourceAltered, fullpath); // altered
+ } else {
+ if (!seal.optional())
+ ctx.reportProblem(errSecCSBadResource, kSecCFErrorResourceMissing, fullpath); // was sealed but is now missing
+ else
+ return; // validly missing
+ }
+ } else
+ ctx.reportProblem(errSecCSBadResource, kSecCFErrorResourceAdded, CFTempURL(path, false, resourceBase()));
+ } else
+ MacOSError::throwMe(errSecCSResourcesNotSealed);
+}
+
+
+//
+// Test a CodeDirectory flag.
+// Returns false if there is no CodeDirectory.
+// May throw if the CodeDirectory is present but somehow invalid.
+//
+bool SecStaticCode::flag(uint32_t tested)
+{
+ if (const CodeDirectory *cd = this->codeDirectory(false))
+ return cd->flags & tested;
+ else
+ return false;
+}
+
+
+//
+// Retrieve the full SuperBlob containing all internal requirements.
+//
+const Requirements *SecStaticCode::internalRequirements()
+{
+ if (CFDataRef req = component(cdRequirementsSlot))
+ return (const Requirements *)CFDataGetBytePtr(req);
+ else
+ return NULL;
+}
+
+
+//
+// Retrieve a particular internal requirement by type.
+//
+const Requirement *SecStaticCode::internalRequirement(SecRequirementType type)
+{
+ if (const Requirements *reqs = internalRequirements())
+ return reqs->find<Requirement>(type);
+ else
+ return NULL;
+}
+
+
+//
+// Return the Designated Requirement (DR). This can be either explicit in the
+// Internal Requirements component, or implicitly generated on demand here.
+// Note that an explicit DR may have been implicitly generated at signing time;
+// we don't distinguish this case.
+//
+const Requirement *SecStaticCode::designatedRequirement()
+{
+ if (const Requirement *req = internalRequirement(kSecDesignatedRequirementType)) {
+ return req; // explicit in signing data
+ } else {
+ if (!mDesignatedReq)
+ mDesignatedReq = defaultDesignatedRequirement();
+ return mDesignatedReq;
+ }
+}
+
+
+//
+// Generate the default Designated Requirement (DR) for this StaticCode.
+// Ignore any explicit DR it may contain.
+//
+const Requirement *SecStaticCode::defaultDesignatedRequirement()
+{
+ if (flag(kSecCodeSignatureAdhoc)) {
+ // adhoc signature: return a plain cdhash requirement
+ Requirement::Maker maker;
+ SHA1 hash;
+ hash(codeDirectory(), codeDirectory()->length());
+ SHA1::Digest digest;
+ hash.finish(digest);
+ maker.cdhash(digest);
+ return maker.make();
+ } else {
+ // full signature: Gin up full context and let DRMaker do its thing
+ validateDirectory(); // need the cert chain
+ Requirement::Context context(this->certificates(),
+ this->infoDictionary(),
+ this->entitlements(),
+ this->identifier(),
+ this->codeDirectory()
+ );
+ return DRMaker(context).make();
+ }
+}
+
+
+//
+// Validate a SecStaticCode against the internal requirement of a particular type.
+//
+void SecStaticCode::validateRequirements(SecRequirementType type, SecStaticCode *target,
+ OSStatus nullError /* = noErr */)
+{
+ DTRACK(CODESIGN_EVAL_STATIC_INTREQ, this, type, target, nullError);
+ if (const Requirement *req = internalRequirement(type))
+ target->validateRequirement(req, nullError ? nullError : errSecCSReqFailed);
+ else if (nullError)
+ MacOSError::throwMe(nullError);
+ else
+ /* accept it */;
+}
+
+
+//
+// Validate this StaticCode against an external Requirement
+//
+bool SecStaticCode::satisfiesRequirement(const Requirement *req, OSStatus failure)
+{
+ assert(req);
+ validateDirectory();
+ return req->validates(Requirement::Context(mCertChain, infoDictionary(), entitlements(), codeDirectory()->identifier(), codeDirectory()), failure);
+}
+
+void SecStaticCode::validateRequirement(const Requirement *req, OSStatus failure)
+{
+ if (!this->satisfiesRequirement(req, failure))
+ MacOSError::throwMe(failure);
+}
+
+
+//
+// Retrieve one certificate from the cert chain.
+// Positive and negative indices can be used:
+// [ leaf, intermed-1, ..., intermed-n, anchor ]
+// 0 1 ... -2 -1
+// Returns NULL if unavailable for any reason.
+//
+SecCertificateRef SecStaticCode::cert(int ix)
+{
+ validateDirectory(); // need cert chain
+ if (mCertChain) {
+ CFIndex length = CFArrayGetCount(mCertChain);
+ if (ix < 0)
+ ix += length;
+ if (ix >= 0 && ix < length)
+ return SecCertificateRef(CFArrayGetValueAtIndex(mCertChain, ix));
+ }
+ return NULL;
+}
+
+CFArrayRef SecStaticCode::certificates()
+{
+ validateDirectory(); // need cert chain
+ return mCertChain;
+}
+
+
+//
+// Gather (mostly) API-official information about this StaticCode.
+//
+// This method lives in the twilight between the API and internal layers,
+// since it generates API objects (Sec*Refs) for return.
+//
+CFDictionaryRef SecStaticCode::signingInformation(SecCSFlags flags)
+{
+ //
+ // Start with the pieces that we return even for unsigned code.
+ // This makes Sec[Static]CodeRefs useful as API-level replacements
+ // of our internal OSXCode objects.
+ //
+ CFRef<CFMutableDictionaryRef> dict = makeCFMutableDictionary(1,
+ kSecCodeInfoMainExecutable, CFTempURL(this->mainExecutablePath()).get()
+ );
+
+ //
+ // If we're not signed, this is all you get
+ //
+ if (!this->isSigned())
+ return dict.yield();
+
+ //
+ // Add the generic attributes that we always include
+ //
+ CFDictionaryAddValue(dict, kSecCodeInfoIdentifier, CFTempString(this->identifier()));
+ CFDictionaryAddValue(dict, kSecCodeInfoFormat, CFTempString(this->format()));
+ CFDictionaryAddValue(dict, kSecCodeInfoSource, CFTempString(this->signatureSource()));
+ CFDictionaryAddValue(dict, kSecCodeInfoUnique, this->cdHash());
+ CFDictionaryAddValue(dict, kSecCodeInfoDigestAlgorithm, CFTempNumber(this->codeDirectory(false)->hashType));
+
+ //
+ // Deliver any Info.plist only if it looks intact
+ //
+ try {
+ if (CFDictionaryRef info = this->infoDictionary())
+ CFDictionaryAddValue(dict, kSecCodeInfoPList, info);
+ } catch (...) { } // don't deliver Info.plist if questionable
+
+ //
+ // kSecCSSigningInformation adds information about signing certificates and chains
+ //
+ if (flags & kSecCSSigningInformation) {
+ if (CFArrayRef certs = this->certificates())
+ CFDictionaryAddValue(dict, kSecCodeInfoCertificates, certs);
+ if (CFDataRef sig = this->signature())
+ CFDictionaryAddValue(dict, kSecCodeInfoCMS, sig);
+ if (mTrust)
+ CFDictionaryAddValue(dict, kSecCodeInfoTrust, mTrust);
+ if (CFAbsoluteTime time = this->signingTime())
+ if (CFRef<CFDateRef> date = CFDateCreate(NULL, time))
+ CFDictionaryAddValue(dict, kSecCodeInfoTime, date);
+ if (CFAbsoluteTime time = this->signingTimestamp())
+ if (CFRef<CFDateRef> date = CFDateCreate(NULL, time))
+ CFDictionaryAddValue(dict, kSecCodeInfoTimestamp, date);
+ }
+
+ //
+ // kSecCSRequirementInformation adds information on requirements
+ //
+ if (flags & kSecCSRequirementInformation) {
+ if (const Requirements *reqs = this->internalRequirements()) {
+ CFDictionaryAddValue(dict, kSecCodeInfoRequirements,
+ CFTempString(Dumper::dump(reqs)));
+ CFDictionaryAddValue(dict, kSecCodeInfoRequirementData, CFTempData(*reqs));
+ }
+
+ const Requirement *dreq = this->designatedRequirement();
+ CFRef<SecRequirementRef> dreqRef = (new SecRequirement(dreq))->handle();
+ CFDictionaryAddValue(dict, kSecCodeInfoDesignatedRequirement, dreqRef);
+ if (this->internalRequirement(kSecDesignatedRequirementType)) { // explicit
+ CFRef<SecRequirementRef> ddreqRef = (new SecRequirement(this->defaultDesignatedRequirement(), true))->handle();
+ CFDictionaryAddValue(dict, kSecCodeInfoImplicitDesignatedRequirement, ddreqRef);
+ } else { // implicit
+ CFDictionaryAddValue(dict, kSecCodeInfoImplicitDesignatedRequirement, dreqRef);
+ }
+
+ if (CFDataRef ent = this->component(cdEntitlementSlot)) {
+ CFDictionaryAddValue(dict, kSecCodeInfoEntitlements, ent);
+ if (CFDictionaryRef entdict = this->entitlements())
+ CFDictionaryAddValue(dict, kSecCodeInfoEntitlementsDict, entdict);
+ }
+ }
+
+ //
+ // kSecCSInternalInformation adds internal information meant to be for Apple internal
+ // use (SPI), and not guaranteed to be stable. Primarily, this is data we want
+ // to reliably transmit through the API wall so that code outside the Security.framework
+ // can use it without having to play nasty tricks to get it.
+ //
+ if (flags & kSecCSInternalInformation) {
+ if (mDir)
+ CFDictionaryAddValue(dict, kSecCodeInfoCodeDirectory, mDir);
+ CFDictionaryAddValue(dict, kSecCodeInfoCodeOffset, CFTempNumber(mRep->signingBase()));
+ if (CFDictionaryRef resources = resourceDictionary())
+ CFDictionaryAddValue(dict, kSecCodeInfoResourceDirectory, resources);
+ }
+
+
+ //
+ // kSecCSContentInformation adds more information about the physical layout
+ // of the signed code. This is (only) useful for packaging or patching-oriented
+ // applications.
+ //
+ if (flags & kSecCSContentInformation)
+ if (CFRef<CFArrayRef> files = mRep->modifiedFiles())
+ CFDictionaryAddValue(dict, kSecCodeInfoChangedFiles, files);
+
+ return dict.yield();
+}
+
+
+//
+// Resource validation contexts.
+// The default context simply throws a CSError, rudely terminating the operation.
+//
+SecStaticCode::ValidationContext::~ValidationContext()
+{ /* virtual */ }
+
+void SecStaticCode::ValidationContext::reportProblem(OSStatus rc, CFStringRef type, CFTypeRef value)
+{
+ CSError::throwMe(rc, type, value);
+}
+
+void SecStaticCode::CollectingContext::reportProblem(OSStatus rc, CFStringRef type, CFTypeRef value)
+{
+ if (mStatus == noErr)
+ mStatus = rc; // record first failure for eventual error return
+ if (type) {
+ if (!mCollection)
+ mCollection.take(makeCFMutableDictionary());
+ CFMutableArrayRef element = CFMutableArrayRef(CFDictionaryGetValue(mCollection, type));
+ if (!element) {
+ element = makeCFMutableArray(0);
+ if (!element)
+ CFError::throwMe();
+ CFDictionaryAddValue(mCollection, type, element);
+ CFRelease(element);
+ }
+ CFArrayAppendValue(element, value);
+ }
+}
+
+void SecStaticCode::CollectingContext::throwMe()
+{
+ assert(mStatus != noErr);
+ throw CSError(mStatus, mCollection.retain());
+}
+
+
+//
+// SecStaticCode::AllArchitectures produces SecStaticCode objects separately
+// for each architecture represented by a base object.
+//
+// Performance note: This is a simple, straight-forward implementation that
+// does not heroically try to share resources between the code objects produced.
+// In practice, this means we'll re-open files and re-read resource files.
+// In exchange, we enter all the code paths in the normal way, and do not have
+// special sharing paths to worry about.
+// If a performance tool brings you here because you have *proof* of a performance
+// problem, consider digging up MachO and Universal (for sharing file descriptors),
+// and SecStaticCode (for sharing resource iterators). That ought to cover most of
+// the big chunks. If you're just offended by the simplicity of this implementation,
+// go play somewhere else.
+//
+SecStaticCode::AllArchitectures::AllArchitectures(SecStaticCode *code)
+ : mBase(code)
+{
+ if (Universal *fat = code->diskRep()->mainExecutableImage()) {
+ fat->architectures(mArchitectures);
+ mCurrent = mArchitectures.begin();
+ mState = fatBinary;
+ } else {
+ mState = firstNonFat;
+ }
+}
+
+SecStaticCode *SecStaticCode::AllArchitectures::operator () ()
+{
+ switch (mState) {
+ case firstNonFat:
+ mState = atEnd;
+ return mBase;
+ case fatBinary:
+ {
+ if (mCurrent == mArchitectures.end())
+ return NULL;
+ Architecture arch = *mCurrent++;
+ if (arch == mBase->diskRep()->mainExecutableImage()->bestNativeArch()) {
+ return mBase;
+ } else {
+ DiskRep::Context ctx;
+ ctx.arch = arch;
+ return new SecStaticCode(DiskRep::bestGuess(mBase->mainExecutablePath(), &ctx));
+ }
+ }
+ default:
+ return NULL;
+ }
+}
+
+
+} // end namespace CodeSigning
+} // end namespace Security
projects / apple / security.git / blobdiff