X-Git-Url: https://git.saurik.com/apple/security.git/blobdiff_plain/72a12576750f52947eb043106ba5c12c0d07decf..b1ab9ed8d0e0f1c3b66d7daa8fd5564444c56195:/libsecurity_codesigning/lib/StaticCode.cpp?ds=sidebyside diff --git a/libsecurity_codesigning/lib/StaticCode.cpp b/libsecurity_codesigning/lib/StaticCode.cpp new file mode 100644 index 00000000..9a124458 --- /dev/null +++ b/libsecurity_codesigning/lib/StaticCode.cpp @@ -0,0 +1,1192 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +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(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(&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 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(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(object)) + return scode; + else if (SecCode *code = dynamic_cast(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(object)) + return NULL; + else if (SecCode *code = dynamic_cast(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 &cache = mCache[slot]; + if (!cache) { + if (CFRef 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(CFDataGetBytePtr(mDir)); + dir->checkIntegrity(); + } + } + if (mDir) + return reinterpret_cast(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 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 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 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 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 core; + MacOSError::check(SecPolicyCopy(CSSM_CERT_X_509v3, + &CSSMOID_APPLE_TP_CODE_SIGNING, &core.aref())); + if (flags & kSecCSEnforceRevocationChecks) { + CFRef crl = makeCRLPolicy(); + CFRef 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(sealedResources, "rules"); + CFDictionaryRef files = cfget(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 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(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(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 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 fullpath = makeCFURL(path, false, resourceBase()); + if (CFRef data = cfLoadFile(fullpath)) { + MakeHash 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 fullpath = makeCFURL(path, false, resourceBase()); + AutoFileDesc fd(cfString(fullpath), O_RDONLY, FileDesc::modeMissingOk); // open optional filee + if (fd) { + MakeHash 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(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 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 date = CFDateCreate(NULL, time)) + CFDictionaryAddValue(dict, kSecCodeInfoTime, date); + if (CFAbsoluteTime time = this->signingTimestamp()) + if (CFRef 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 dreqRef = (new SecRequirement(dreq))->handle(); + CFDictionaryAddValue(dict, kSecCodeInfoDesignatedRequirement, dreqRef); + if (this->internalRequirement(kSecDesignatedRequirementType)) { // explicit + CFRef 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 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