Security-55163.44.tar.gz

[apple/security.git] / libsecurity_apple_x509_tp / lib / TPCertInfo.cpp

/*
 * Copyright (c) 2000-2011 Apple Inc. All Rights Reserved.
 * 
 * The contents of this file constitute Original Code as defined in and are
 * subject to the Apple Public Source License Version 1.2 (the 'License').
 * You may not use this file except in compliance with the License. Please obtain
 * a copy of the License at http://www.apple.com/publicsource and read it before
 * using this file.
 * 
 * This 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.
 */


/*
 * TPCertInfo.cpp - TP's private certificate info classes
 */

#include "TPCertInfo.h"
#include "tpdebugging.h"
#include "tpTime.h"
#include "certGroupUtils.h"
#include "TPDatabase.h"
#include "TPNetwork.h"
#include <Security/cssmapi.h>
#include <Security/x509defs.h>
#include <Security/oidscert.h>
#include <Security/oidsalg.h>
#include <string.h>                                             /* for memcmp */
#include <security_utilities/threading.h> /* for Mutex */
#include <security_utilities/globalizer.h>
#include <security_utilities/debugging.h>
#include <security_cdsa_utilities/cssmerrors.h>
#include <Security/cssmapple.h>
#include <Security/SecCertificate.h>
#include <Security/SecImportExport.h>
#include <Security/SecTrustSettingsPriv.h>

#define tpTimeDbg(args...)              secdebug("tpTime", ## args) 
#define tpCertInfoDbg(args...)  secdebug("tpCert", ## args)

static const TPClItemCalls tpCertClCalls =
{
        CSSM_CL_CertGetFirstCachedFieldValue,
        CSSM_CL_CertAbortQuery,
        CSSM_CL_CertCache,
        CSSM_CL_CertAbortCache,
        CSSM_CL_CertVerify,
        &CSSMOID_X509V1ValidityNotBefore,
        &CSSMOID_X509V1ValidityNotAfter,
        CSSMERR_TP_INVALID_CERT_POINTER,
        CSSMERR_TP_CERT_EXPIRED,
        CSSMERR_TP_CERT_NOT_VALID_YET
};

TPClItemInfo::TPClItemInfo(
        CSSM_CL_HANDLE          clHand,
        CSSM_CSP_HANDLE         cspHand,
        const TPClItemCalls     &clCalls,
        const CSSM_DATA         *itemData,
        TPItemCopy                      copyItemData,
        const char                      *verifyTime)    // may be NULL
                :       
                        mClHand(clHand),
                        mCspHand(cspHand),
                        mClCalls(clCalls),
                        mWeOwnTheData(false),
                        mCacheHand(0),
                        mIssuerName(NULL),
                        mItemData(NULL),
                        mSigAlg(CSSM_ALGID_NONE),
                        mNotBefore(NULL),
                        mNotAfter(NULL),
                        mIsExpired(false),
                        mIsNotValidYet(false),
                        mIndex(0)
{
        try {
                CSSM_RETURN crtn = cacheItem(itemData, copyItemData);
                if(crtn) {
                        CssmError::throwMe(crtn);
                }                       
                        
                /* 
                 * Fetch standard fields...
                 * Issue name assumes same OID for Certs and CRLs!
                 */
                crtn = fetchField(&CSSMOID_X509V1IssuerName, &mIssuerName);
                if(crtn) {
                        CssmError::throwMe(crtn);
                }
                
                /* 
                 * Signing algorithm, infer from TBS algId 
                 * Note this assumes that the OID for fetching this field is the
                 * same for CRLs and Certs.
                 */
                CSSM_DATA_PTR algField;
                crtn = fetchField(&CSSMOID_X509V1SignatureAlgorithmTBS, &algField);
                if(crtn) {
                        releaseResources();
                        CssmError::throwMe(crtn);
                }
                if(algField->Length != sizeof(CSSM_X509_ALGORITHM_IDENTIFIER)) {
                        tpErrorLog("TPClItemInfo: bad CSSM_X509_ALGORITHM_IDENTIFIER\n");
                        CssmError::throwMe(CSSMERR_TP_INTERNAL_ERROR);
                }
                CSSM_X509_ALGORITHM_IDENTIFIER *algId = 
                        (CSSM_X509_ALGORITHM_IDENTIFIER *)algField->Data;
                bool algFound = cssmOidToAlg(&algId->algorithm, &mSigAlg);
                if(!algFound) {
                        tpErrorLog("TPClItemInfo: unknown signature algorithm\n");
                        CssmError::throwMe(CSSMERR_TP_UNKNOWN_FORMAT);
                }
                if(mSigAlg == CSSM_ALGID_ECDSA_SPECIFIED) {
                        /* Further processing needed to get digest algorithm */
                        if(decodeECDSA_SigAlgParams(&algId->parameters, &mSigAlg)) {
                                tpErrorLog("TPClItemInfo: incomplete/unknown ECDSA signature algorithm\n");
                                CssmError::throwMe(CSSMERR_TP_UNKNOWN_FORMAT);
                        }
                }
                freeField(&CSSMOID_X509V1SignatureAlgorithmTBS, algField);
        
                fetchNotBeforeAfter();
                calculateCurrent(verifyTime);
        }
        catch(...) {
                releaseResources();
                throw;
        }
}

TPClItemInfo::~TPClItemInfo()
{
        tpCertInfoDbg("TPClItemInfo destruct this %p", this);
        releaseResources();
}

void TPClItemInfo::releaseResources()
{
        if(mWeOwnTheData && (mItemData != NULL)) {
                tpFreeCssmData(Allocator::standard(), mItemData, CSSM_TRUE);
                mWeOwnTheData = false;
                mItemData = NULL;
        }
        if(mIssuerName) {
                freeField(&CSSMOID_X509V1IssuerName, mIssuerName);
                mIssuerName = NULL;
        }
        if(mCacheHand != 0) {
                mClCalls.abortCache(mClHand, mCacheHand);
                mCacheHand = 0;
        }
        if(mNotBefore) {
                CFRelease(mNotBefore);
                mNotBefore = NULL;
        }
        if(mNotAfter) {
                CFRelease(mNotAfter);
                mNotAfter = NULL;
        }
}

/* fetch arbitrary field from cached cert */
CSSM_RETURN TPClItemInfo::fetchField(
        const CSSM_OID  *fieldOid,
        CSSM_DATA_PTR   *fieldData)             // mallocd by CL and RETURNED
{
        CSSM_RETURN crtn;
        
        uint32 NumberOfFields = 0;
        CSSM_HANDLE resultHand = 0;
        *fieldData = NULL;

        assert(mClCalls.getField != NULL);
        assert(mCacheHand != 0);
        crtn = mClCalls.getField(
                mClHand,
                mCacheHand,
            fieldOid,
            &resultHand,
            &NumberOfFields,
                fieldData);
        if(crtn) {
                return crtn;
        }
        if(NumberOfFields != 1) {
                tpErrorLog("TPCertInfo::fetchField: numFields %d, expected 1\n", 
                        (int)NumberOfFields);
        }
        mClCalls.abortQuery(mClHand, resultHand);
        return CSSM_OK;
}

/* free arbitrary field obtained from fetchField() */
CSSM_RETURN TPClItemInfo::freeField( 
        const CSSM_OID  *fieldOid,
        CSSM_DATA_PTR   fieldData)      
{
        return CSSM_CL_FreeFieldValue(mClHand, fieldOid, fieldData);

}

/* 
 * Verify with an issuer cert - works on certs and CRLs.
 * Issuer/subject name match already performed by caller.
 * Optional paramCert is used to provide parameters when issuer
 * has a partial public key.
 */
CSSM_RETURN TPClItemInfo::verifyWithIssuer(
        TPCertInfo              *issuerCert,
        TPCertInfo              *paramCert /* = NULL */) const
{
        CSSM_RETURN     crtn;

        assert(mClHand != 0);
        assert(issuerCert->isIssuerOf(*this));
        assert(mCspHand != 0);
        
        /*
         * Special case: detect partial public key right now; don't even 
         * bother trying the cert verify in that case.
         */
        if(issuerCert->hasPartialKey() && (paramCert == NULL)) {
                /* caller deals with this later */
                tpVfyDebug("verifyWithIssuer PUBLIC_KEY_INCOMPLETE");
                return CSSMERR_CSP_APPLE_PUBLIC_KEY_INCOMPLETE;
        }
        
        CSSM_CC_HANDLE ccHand;
        crtn = CSSM_CSP_CreateSignatureContext(mCspHand,
                mSigAlg,
                NULL,                   // Access Creds
                issuerCert->pubKey(),
                &ccHand);
        if(crtn != CSSM_OK) {
                tpErrorLog("verifyWithIssuer: CreateSignatureContext error\n");
                CssmError::throwMe(crtn);
        }
        if(paramCert != NULL) {
                assert(issuerCert->hasPartialKey());
                
                /* add in parameter-bearing key */
                CSSM_CONTEXT_ATTRIBUTE          newAttr;        
                
                newAttr.AttributeType   = CSSM_ATTRIBUTE_PARAM_KEY;
                newAttr.AttributeLength = sizeof(CSSM_KEY);
                newAttr.Attribute.Key   = paramCert->pubKey();
                crtn = CSSM_UpdateContextAttributes(ccHand, 1, &newAttr);
                if(crtn) {
                        tpErrorLog("verifyWithIssuer: CSSM_UpdateContextAttributes error\n");
                        CssmError::throwMe(crtn);
                }
        }
        crtn = mClCalls.itemVerify(mClHand, 
        ccHand, 
        mItemData,
        NULL,                           // issuer cert
        NULL,                           // VerifyScope
        0);                                     // ScopeSize

        switch(crtn) {
                case CSSM_OK:           // success
                case CSSMERR_CSP_APPLE_PUBLIC_KEY_INCOMPLETE:   // caller handles
                        tpVfyDebug("verifyWithIssuer GOOD");
                        break;
                default:
                        /* all others appear here as general cert verify error */
                        crtn = CSSMERR_TP_VERIFICATION_FAILURE;
                        tpVfyDebug("verifyWithIssuer BAD");
                        break;
        }
        CSSM_DeleteContext(ccHand);
        return crtn;
}

CSSM_RETURN TPClItemInfo::cacheItem(
        const CSSM_DATA         *itemData,
        TPItemCopy                      copyItemData)                                                                                           
{
        switch(copyItemData) {
                case TIC_NoCopy:
                        mItemData = const_cast<CSSM_DATA *>(itemData);
                        break;
                case TIC_CopyData:
                        mItemData = tpMallocCopyCssmData(Allocator::standard(), itemData);
                        mWeOwnTheData = true;
                        break;
                default:
                        assert(0);
                        CssmError::throwMe(CSSMERR_TP_INTERNAL_ERROR);
        }
        
        /* cache the cert/CRL in the CL */
        return mClCalls.cacheItem(mClHand, mItemData, &mCacheHand);
}

/* 
 * Calculate not before/after times as struct tm. Only throws on 
 * gross error (CSSMERR_TP_INVALID_CERT_POINTER, etc.).
 *
 * Only differences between Cert and CRL flavors of this are the 
 * OIDs used to fetch the appropriate before/after times, both of
 * which are expressed as CSSM_X509_TIME structs for both Certs 
 * and CRLS.
 */
void TPClItemInfo::fetchNotBeforeAfter()
{
        CSSM_DATA_PTR   notBeforeField = NULL;
        CSSM_DATA_PTR   notAfterField = NULL;
        CSSM_RETURN             crtn = CSSM_OK;
        CSSM_X509_TIME  *xTime;
        
        assert(cacheHand() != CSSM_INVALID_HANDLE);
        crtn = fetchField(mClCalls.notBeforeOid, &notBeforeField);
        if(crtn) {
                tpErrorLog("fetchNotBeforeAfter: GetField error\n");
                CssmError::throwMe(mClCalls.invalidItemRtn);
        }
        
        /* subsequent errors to errOut */
        xTime = (CSSM_X509_TIME *)notBeforeField->Data;
        if(timeStringToCfDate((char *)xTime->time.Data, xTime->time.Length, &mNotBefore)) {
                tpErrorLog("fetchNotBeforeAfter: malformed notBefore time\n");
                crtn = mClCalls.invalidItemRtn;
                goto errOut;
        }

        crtn = fetchField(mClCalls.notAfterOid, &notAfterField);
        if(crtn) {
                /*
                 * Tolerate a missing NextUpdate in CRL only 
                 */
                if(mClCalls.notAfterOid == &CSSMOID_X509V1ValidityNotAfter) {
                        tpErrorLog("fetchNotBeforeAfter: GetField error\n");
                        crtn = mClCalls.invalidItemRtn;
                        goto errOut;
                }
                else {
                        /*
                         * Fake NextUpdate to be "at the end of time"
                         */
                        timeStringToCfDate(CSSM_APPLE_CRL_END_OF_TIME, 
                                strlen(CSSM_APPLE_CRL_END_OF_TIME), 
                                &mNotAfter);
                }
        }
        else {
                xTime = (CSSM_X509_TIME *)notAfterField->Data;
                if(timeStringToCfDate((char *)xTime->time.Data, xTime->time.Length, &mNotAfter)) {
                        tpErrorLog("fetchNotBeforeAfter: malformed notAfter time\n");
                        crtn = mClCalls.invalidItemRtn;
                        goto errOut;
                }
        }
        crtn = CSSM_OK;
errOut:
        if(notAfterField) {
                freeField(mClCalls.notAfterOid, notAfterField);
        }
        if(notBeforeField) {
                freeField(mClCalls.notBeforeOid, notBeforeField);
        }
        if(crtn != CSSM_OK) {
                CssmError::throwMe(crtn);
        }
}

/* 
 * Verify validity (not before/after) by comparing the reference
 * time (verifyString if present, or "now" if NULL) to the 
 * not before/after fields fetched from the item at construction.
 *
 * Called implicitly at construction; can be called again any time
 * to re-establish validity (e.g. after fetching an item from a cache).
 *
 * We use some stdlib time calls over in tpTime.c; the stdlib function
 * gmtime() is not thread-safe, so we do the protection here. Note that
 * this makes *our* calls to gmtime() thread-safe, but if the app has
 * other threads which are also calling gmtime, we're out of luck.
 */
ModuleNexus<Mutex> tpTimeLock;

CSSM_RETURN TPClItemInfo::calculateCurrent(
        const char                      *verifyString)
{
        CFDateRef refTime = NULL;
        
        if(verifyString != NULL) {
                /* caller specifies verification time base */
                if(timeStringToCfDate(verifyString, strlen(verifyString), &refTime)) {
                        tpErrorLog("calculateCurrent: timeStringToCfDate error\n");
                        return CSSMERR_TP_INVALID_TIMESTRING;
                }
        }
        else {
                /* time base = right now */
                refTime = CFDateCreate(NULL, CFAbsoluteTimeGetCurrent());
        }
        if(compareTimes(refTime, mNotBefore) < 0) {
                mIsNotValidYet = true;
                tpTimeDbg("\nTP_CERT_NOT_VALID_YET: now %g notBefore %g", 
                        CFDateGetAbsoluteTime(refTime), CFDateGetAbsoluteTime(mNotBefore));
                CFRelease(refTime);
                return mClCalls.notValidYetRtn;
        }
        else {
                mIsNotValidYet = false;
        }

        if(compareTimes(refTime, mNotAfter) > 0) {
                mIsExpired = true;
                tpTimeDbg("\nTP_CERT_EXPIRED: now %g notBefore %g", 
                        CFDateGetAbsoluteTime(refTime), CFDateGetAbsoluteTime(mNotBefore));
                CFRelease(refTime);
                return mClCalls.expiredRtn;
        }
        else {
                mIsExpired = false;
                CFRelease(refTime);
                return CSSM_OK;
        }
}


/* 
 * No default constructor - this is the only way.
 * This caches the cert and fetches subjectName, issuerName, and
 * mPublicKey to ensure the incoming certData is well-constructed.
 */
TPCertInfo::TPCertInfo(
        CSSM_CL_HANDLE          clHand,
        CSSM_CSP_HANDLE         cspHand,
        const CSSM_DATA         *certData,
        TPItemCopy                      copyCertData,           // true: we copy, we free
                                                                                        // false - caller owns
        const char                      *verifyTime)            // may be NULL
        :
                TPClItemInfo(clHand, cspHand, tpCertClCalls, certData, 
                        copyCertData, verifyTime),
                mSubjectName(NULL),
                mPublicKeyData(NULL),
                mPublicKey(NULL),
                mIsAnchor(false),
                mIsFromInputCerts(false),
                mIsFromNet(false),
                mNumStatusCodes(0),
                mStatusCodes(NULL),
                mUniqueRecord(NULL),
                mUsed(false),
                mIsLeaf(false),
                mIsRoot(TRS_Unknown),
                mRevCheckGood(false),
                mRevCheckComplete(false),
                mTrustSettingsEvaluated(false),
                mTrustSettingsDomain(kSecTrustSettingsDomainSystem),
                mTrustSettingsResult(kSecTrustSettingsResultInvalid),
                mTrustSettingsFoundAnyEntry(false),
                mTrustSettingsFoundMatchingEntry(false),
                mAllowedErrs(NULL),
                mNumAllowedErrs(0),
                mIgnoredError(false),
                mTrustSettingsKeyUsage(0),
                mCertHashStr(NULL)
{
        CSSM_RETURN     crtn;

        tpCertInfoDbg("TPCertInfo construct this %p", this);
        mDlDbHandle.DLHandle = 0;
        mDlDbHandle.DBHandle = 0;
        
        /* fetch subject name */
        crtn = fetchField(&CSSMOID_X509V1SubjectName, &mSubjectName);
        if(crtn) {
                /* bad cert */
                releaseResources();
                CssmError::throwMe(crtn);
        }
        
        /* this cert's public key */
        crtn = fetchField(&CSSMOID_CSSMKeyStruct, &mPublicKeyData);
        if(crtn || (mPublicKeyData->Length != sizeof(CSSM_KEY))) {
                /* bad cert */
                releaseResources();
                CssmError::throwMe(crtn);
        }
        mPublicKey = (CSSM_KEY_PTR)mPublicKeyData->Data;
        
        /* calculate other commonly used fields */
        if(tpCompareCssmData(mSubjectName, issuerName())) {
                /*
                 * Per Radar 3374978, perform complete signature verification
                 * lazily - just check subject/issuer match here.
                 */
                tpAnchorDebug("TPCertInfo potential anchor");
                mIsRoot = TRS_NamesMatch;
        }
        else {
                mIsRoot = TRS_NotRoot;
        }
}
        
/* frees mSubjectName, mIssuerName, mCacheHand via mClHand */
TPCertInfo::~TPCertInfo()
{
        tpCertInfoDbg("TPCertInfo destruct this %p", this);
        releaseResources();
}

void TPCertInfo::releaseResources()
{
        if(mSubjectName) {
                freeField(&CSSMOID_X509V1SubjectName, mSubjectName);
                mSubjectName = NULL;
        }
        if(mPublicKeyData) {
                freeField(&CSSMOID_CSSMKeyStruct, mPublicKeyData);
                mPublicKey = NULL;
                mPublicKeyData = NULL;
        }
        if(mStatusCodes) {
                free(mStatusCodes);
                mStatusCodes = NULL;
        }
        if(mAllowedErrs) {
                free(mAllowedErrs);
        }
        if(mCertHashStr) {
                CFRelease(mCertHashStr);
        }
        TPClItemInfo::releaseResources();
}

const CSSM_DATA *TPCertInfo::subjectName()
{
        assert(mSubjectName != NULL);
        return mSubjectName;
}

/* 
 * Perform semi-lazy evaluation of "rootness". Subject and issuer names
 * compared at constructor.
 * If avoidVerify is true, we won't do the signature verify: caller 
 * just wants to know if the subject and issuer names match.
 */
bool TPCertInfo::isSelfSigned(bool avoidVerify)
{
        switch(mIsRoot) {
                case TRS_NotRoot:                       // known not to be root
                        return false;
                case TRS_IsRoot:
                        return true;
                case TRS_NamesMatch:
                        if(avoidVerify) {
                                return true;
                        }
                        /* else drop through and verify */
                case TRS_Unknown:                       // actually shouldn't happen, but to be safe...
                default:
                        /* do the signature verify */
                        if(verifyWithIssuer(this) == CSSM_OK) {
                                tpAnchorDebug("isSelfSigned anchor verified");
                                mIsRoot = TRS_IsRoot;
                                return true;
                        }
                        else {
                                tpAnchorDebug("isSelfSigned anchor vfy FAIL");
                                mIsRoot = TRS_NotRoot;
                                return false;
                        }
        }
}

/*
 * Am I the issuer of the specified subject item? Returns true if so.
 * Works for subject certs as well as CRLs. 
 */
bool TPCertInfo::isIssuerOf(
        const TPClItemInfo      &subject)
{
        assert(mSubjectName != NULL);
        assert(subject.issuerName() != NULL);
        if(tpCompareCssmData(mSubjectName, subject.issuerName())) {
                return true;
        }
        else {
                return false;
        }
}

bool TPCertInfo::addStatusCode(CSSM_RETURN code)
{
        mNumStatusCodes++;
        mStatusCodes = (CSSM_RETURN *)realloc(mStatusCodes, 
                mNumStatusCodes * sizeof(CSSM_RETURN));
        mStatusCodes[mNumStatusCodes - 1] = code;
        return isStatusFatal(code);
}

bool TPCertInfo::hasStatusCode(CSSM_RETURN code)
{
        for(unsigned dex=0; dex<mNumStatusCodes; dex++) {
                if(mStatusCodes[dex] == code) {
                        return true;
                }
        }
        return false;
}

bool TPCertInfo::isStatusFatal(CSSM_RETURN code)
{
        for(unsigned dex=0; dex<mNumAllowedErrs; dex++) {
                if(mAllowedErrs[dex] == code) {
                        tpTrustSettingsDbg("isStatusFatal(%ld): ALLOWED", (unsigned long)code);
                        mIgnoredError = true;
                        return false;
                }
        }
        return true;
}

/* 
 * Indicate whether this cert's public key is a CSSM_KEYATTR_PARTIAL
 * key.
 */
bool TPCertInfo::hasPartialKey()
{
        if(mPublicKey->KeyHeader.KeyAttr & CSSM_KEYATTR_PARTIAL) {
                return true;
        }
        else {
                return false;
        }
}

/*
 * <rdar://9145531>
 */
bool TPCertInfo::shouldReject()
{
        static unsigned char _UTN_UF_H_ISSUER_BYTES[154] = {
          0x30, 0x81, 0x97, 0x31, 0x0b, 0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06,
          0x13, 0x02, 0x55, 0x53, 0x31, 0x0b, 0x30, 0x09, 0x06, 0x03, 0x55, 0x04,
          0x08, 0x13, 0x02, 0x55, 0x54, 0x31, 0x17, 0x30, 0x15, 0x06, 0x03, 0x55,
          0x04, 0x07, 0x13, 0x0e, 0x53, 0x41, 0x4c, 0x54, 0x20, 0x4c, 0x41, 0x4b,
          0x45, 0x20, 0x43, 0x49, 0x54, 0x59, 0x31, 0x1e, 0x30, 0x1c, 0x06, 0x03,
          0x55, 0x04, 0x0a, 0x13, 0x15, 0x54, 0x48, 0x45, 0x20, 0x55, 0x53, 0x45,
          0x52, 0x54, 0x52, 0x55, 0x53, 0x54, 0x20, 0x4e, 0x45, 0x54, 0x57, 0x4f,
          0x52, 0x4b, 0x31, 0x21, 0x30, 0x1f, 0x06, 0x03, 0x55, 0x04, 0x0b, 0x13,
          0x18, 0x48, 0x54, 0x54, 0x50, 0x3a, 0x2f, 0x2f, 0x57, 0x57, 0x57, 0x2e,
          0x55, 0x53, 0x45, 0x52, 0x54, 0x52, 0x55, 0x53, 0x54, 0x2e, 0x43, 0x4f,
          0x4d, 0x31, 0x1f, 0x30, 0x1d, 0x06, 0x03, 0x55, 0x04, 0x03, 0x13, 0x16,
          0x55, 0x54, 0x4e, 0x2d, 0x55, 0x53, 0x45, 0x52, 0x46, 0x49, 0x52, 0x53,
          0x54, 0x2d, 0x48, 0x41, 0x52, 0x44, 0x57, 0x41, 0x52, 0x45
        };
        CSSM_DATA _UTN_UF_H_ISSUER = { sizeof(_UTN_UF_H_ISSUER_BYTES), _UTN_UF_H_ISSUER_BYTES };

        static CSSM_DATA _UTN_UF_H_SERIALS[] = {
                { 17, (uint8*)"\x00\x92\x39\xd5\x34\x8f\x40\xd1\x69\x5a\x74\x54\x70\xe1\xf2\x3f\x43" }, // amo
                { 17, (uint8*)"\x00\xd8\xf3\x5f\x4e\xb7\x87\x2b\x2d\xab\x06\x92\xe3\x15\x38\x2f\xb0" }, // gt
                { 17, (uint8*)"\x00\xb0\xb7\x13\x3e\xd0\x96\xf9\xb5\x6f\xae\x91\xc8\x74\xbd\x3a\xc0" }, // llc
                { 17, (uint8*)"\x00\xe9\x02\x8b\x95\x78\xe4\x15\xdc\x1a\x71\x0a\x2b\x88\x15\x44\x47" }, // lsc
                { 17, (uint8*)"\x00\xd7\x55\x8f\xda\xf5\xf1\x10\x5b\xb2\x13\x28\x2b\x70\x77\x29\xa3" }, // lyc
                { 16, (uint8*)"\x39\x2a\x43\x4f\x0e\x07\xdf\x1f\x8a\xa3\x05\xde\x34\xe0\xc2\x29" },     // lyc1
                { 16, (uint8*)"\x3e\x75\xce\xd4\x6b\x69\x30\x21\x21\x88\x30\xae\x86\xa8\x2a\x71" },     // lyc2
                { 16, (uint8*)"\x04\x7e\xcb\xe9\xfc\xa5\x5f\x7b\xd0\x9e\xae\x36\xe1\x0c\xae\x1e" },     // mgc
                { 17, (uint8*)"\x00\xf5\xc8\x6a\xf3\x61\x62\xf1\x3a\x64\xf5\x4f\x6d\xc9\x58\x7c\x06" }, // wgc
                { 0, NULL }
        };

        const CSSM_DATA *issuer=issuerName();
        if(!issuer || !(tpCompareCssmData(issuer, &_UTN_UF_H_ISSUER)))
                return false;

        CSSM_DATA *serialNumber=NULL;
        CSSM_RETURN crtn = fetchField(&CSSMOID_X509V1SerialNumber, &serialNumber);
        if(crtn || !serialNumber)
                return false;

        CSSM_DATA *p=_UTN_UF_H_SERIALS;
        bool matched=false;
        while(p->Length) {
                if(tpCompareCssmData(serialNumber, p)) {
                        matched=true;
                        addStatusCode(CSSMERR_TP_CERT_REVOKED);
                        break;
                }
                ++p;
        }
        freeField(&CSSMOID_X509V1SerialNumber, serialNumber);
        return matched;
}

/*
 * Evaluate trust settings; returns true in *foundMatchingEntry if positive 
 * match found - i.e., cert chain construction is done. 
 */
OSStatus TPCertInfo::evaluateTrustSettings(
        const CSSM_OID &policyOid,
        const char *policyString,                       // optional
        uint32 policyStringLen,
        SecTrustSettingsKeyUsage keyUse,        // required
        bool *foundMatchingEntry,                       // RETURNED
        bool *foundAnyEntry)                            // RETURNED
{
        /* 
         * We might have to force a re-evaluation if the requested key usage
         * is not a subset of what we already checked for (and cached). 
         */
        if(mTrustSettingsEvaluated) {
                bool doFlush = false;
                if(mTrustSettingsKeyUsage != kSecTrustSettingsKeyUseAny) {
                        if(keyUse == kSecTrustSettingsKeyUseAny) {
                                /* now want "any", checked something else before */
                                doFlush = true;
                        }
                        else if((keyUse & mTrustSettingsKeyUsage) != keyUse) {
                                /* want bits that we didn't ask for before */
                                doFlush = true;
                        }
                }
                if(doFlush) {
                        tpTrustSettingsDbg("evaluateTrustSettings: flushing cached trust for "
                                "%p due to keyUse 0x%x", this, (int)keyUse);
                        mTrustSettingsEvaluated = false;
                        mTrustSettingsFoundAnyEntry = false;
                        mTrustSettingsResult = kSecTrustSettingsResultInvalid;
                        mTrustSettingsFoundMatchingEntry = false;
                        if(mAllowedErrs != NULL) {
                                free(mAllowedErrs);
                        }
                        mNumAllowedErrs = 0;
                }
                /* else we can safely use the cached values */
        }
        if(!mTrustSettingsEvaluated) {
        
                if(mCertHashStr == NULL) {
                        const CSSM_DATA *certData = itemData();
                        mCertHashStr = SecTrustSettingsCertHashStrFromData(certData->Data, 
                                certData->Length);
                }

                OSStatus ortn = SecTrustSettingsEvaluateCert(mCertHashStr,
                        &policyOid,
                        policyString,
                        policyStringLen,
                        keyUse,
                        /* 
                         * This is the purpose of the avoidVerify option, right here.
                         * If this is a root cert and it has trust settings, we avoid
                         * the signature verify. If it turns out there are no trust
                         * settings and this is a root, we'll verify the signature
                         * elsewhere (e.g. post_trust_setting: in buildCertGroup()).
                         */
                        isSelfSigned(true),
                        &mTrustSettingsDomain,
                        &mAllowedErrs,
                        &mNumAllowedErrs,
                        &mTrustSettingsResult,
                        &mTrustSettingsFoundMatchingEntry,
                        &mTrustSettingsFoundAnyEntry);
                if(ortn) {
                        tpTrustSettingsDbg("evaluateTrustSettings: SecTrustSettingsEvaluateCert error!");
                        return ortn;
                }
                mTrustSettingsEvaluated = true;
                mTrustSettingsKeyUsage = keyUse;
                #ifndef NDEBUG
                if(mTrustSettingsFoundMatchingEntry) {
                        tpTrustSettingsDbg("evaluateTrustSettings: found for %p result %d", 
                                this, (int)mTrustSettingsResult);
                }
                #endif
                /* one more thing... */
                if(shouldReject()) {
                        return CSSMERR_TP_INVALID_CERTIFICATE;
                }
        }
        *foundMatchingEntry = mTrustSettingsFoundMatchingEntry;
        *foundAnyEntry = mTrustSettingsFoundAnyEntry;

        return noErr;
}

/* true means "verification terminated due to user trust setting" */
bool TPCertInfo::trustSettingsFound()
{
        switch(mTrustSettingsResult) {
                case kSecTrustSettingsResultUnspecified:        /* entry but not definitive */
                case kSecTrustSettingsResultInvalid:            /* no entry */
                        return false;
                default:
                        return true;
        }
}

/* 
 * Determine if this has an empty SubjectName field. Returns true if so.
 */
bool TPCertInfo::hasEmptySubjectName()
{
        /*
         * A "pure" empty subject is two bytes (0x30 00) - constructed sequence,
         * short form length, length 0. We'll be robust and tolerate a missing
         * field, as well as a possible BER-encoded subject with some extra cruft.
         */
        if((mSubjectName == NULL) || (mSubjectName->Length <= 4)) {
                return true;    
        }
        else {
                return false;   
        }
}

/* 
 * Free mUniqueRecord if it exists.
 * This is *not* done in our destructor because this record sometimes 
 * has to persist in the form of a CSSM evidence chain.
 */
void TPCertInfo::freeUniqueRecord()
{
        if(mUniqueRecord == NULL) {
                return;
        }
        tpDbDebug("freeUniqueRecord: freeing cert record %p", mUniqueRecord);
        CSSM_DL_FreeUniqueRecord(mDlDbHandle, mUniqueRecord);
}

/***
 *** TPCertGroup class
 ***/
 
/* build empty group */
TPCertGroup::TPCertGroup(
        Allocator                       &alloc,
        TPGroupOwner            whoOwns) :
                mAlloc(alloc),
                mCertInfo(NULL),
                mNumCerts(0),
                mSizeofCertInfo(0),
                mWhoOwns(whoOwns)
{
        tpCertInfoDbg("TPCertGroup simple construct this %p", this);
        /* nothing for now */
}
        
/*
 * Construct from unordered, untrusted CSSM_CERTGROUP. Resulting
 * TPCertInfos are more or less in the same order as the incoming
 * certs, though incoming certs are discarded if they don't parse.
 * No verification of any sort is performed. 
 */
TPCertGroup::TPCertGroup(
        const CSSM_CERTGROUP    &CertGroupFrag,
        CSSM_CL_HANDLE                  clHand,
        CSSM_CSP_HANDLE                 cspHand,
        Allocator                               &alloc,
        const char                              *verifyTime,                    // may be NULL
        bool                                    firstCertMustBeValid,
        TPGroupOwner                    whoOwns) :
                mAlloc(alloc),
                mCertInfo(NULL),
                mNumCerts(0),
                mSizeofCertInfo(0),
                mWhoOwns(whoOwns)
{
        tpCertInfoDbg("TPCertGroup hard construct this %p", this);

        /* verify input args */
        if(cspHand == CSSM_INVALID_HANDLE) {
                CssmError::throwMe(CSSMERR_TP_INVALID_CSP_HANDLE);
        }
        if(clHand == CSSM_INVALID_HANDLE)       {
                CssmError::throwMe(CSSMERR_TP_INVALID_CL_HANDLE);
        }
        if(firstCertMustBeValid) {
                if( (CertGroupFrag.NumCerts == 0) ||                    
                (CertGroupFrag.GroupList.CertList[0].Data == NULL) ||
                (CertGroupFrag.GroupList.CertList[0].Length == 0)) {
                                CssmError::throwMe(CSSMERR_TP_INVALID_CERTIFICATE);
                }
        }
        if(CertGroupFrag.CertGroupType != CSSM_CERTGROUP_DATA) {
                CssmError::throwMe(CSSMERR_TP_INVALID_CERTGROUP);
        }
        switch(CertGroupFrag.CertType) {
                case CSSM_CERT_X_509v1:
                case CSSM_CERT_X_509v2:
                case CSSM_CERT_X_509v3:
                        break;
                default:
                        CssmError::throwMe(CSSMERR_TP_UNKNOWN_FORMAT);
        }
        switch(CertGroupFrag.CertEncoding) {
                case CSSM_CERT_ENCODING_BER:
                case CSSM_CERT_ENCODING_DER:
                        break;
                default:
                        CssmError::throwMe(CSSMERR_TP_UNKNOWN_FORMAT);
        }
        
        /* 
         * Add remaining input certs to mCertInfo. 
         */
        TPCertInfo *certInfo = NULL;
        for(unsigned certDex=0; certDex<CertGroupFrag.NumCerts; certDex++) {
                try {
                        certInfo = new TPCertInfo(clHand,
                                cspHand,
                                &CertGroupFrag.GroupList.CertList[certDex],
                                TIC_NoCopy,                     // caller owns
                                verifyTime);
                }
                catch (...) {
                        if((certDex == 0) && firstCertMustBeValid) {
                                CssmError::throwMe(CSSMERR_TP_INVALID_CERTIFICATE);
                        }
                        /* else just ignore this cert */
                        continue;
                }
                certInfo->index(certDex);
                appendCert(certInfo);
        }
}

/*
 * Deletes contents of mCertInfo[] if appropriate.
 */
TPCertGroup::~TPCertGroup()
{
        if(mWhoOwns == TGO_Group) {
                unsigned i;
                for(i=0; i<mNumCerts; i++) {
                        delete mCertInfo[i];
                }
        }
        mAlloc.free(mCertInfo);
}

/* add/remove/access TPTCertInfo's. */
/*
 * NOTE: I am aware that most folks would just use an array<> here, but
 * gdb is so lame that it doesn't even let one examine the contents
 * of an array<> (or just about anything else in the STL). I prefer
 * debuggability over saving a few lines of trivial code.
 */
void TPCertGroup::appendCert(
        TPCertInfo                      *certInfo)                      // appends to end of mCertInfo
{
        if(mNumCerts == mSizeofCertInfo) {
                if(mSizeofCertInfo == 0) {
                        /* appending to empty array */
                        mSizeofCertInfo = 1;
                }
                else {
                        mSizeofCertInfo *= 2;
                }
                mCertInfo = (TPCertInfo **)mAlloc.realloc(mCertInfo, 
                        mSizeofCertInfo * sizeof(TPCertInfo *));
        }
        mCertInfo[mNumCerts++] = certInfo;
}

TPCertInfo *TPCertGroup::certAtIndex(
        unsigned                        index)
{
        if(index > (mNumCerts - 1)) {
                CssmError::throwMe(CSSMERR_TP_INTERNAL_ERROR);
        }
        return mCertInfo[index];
}

TPCertInfo *TPCertGroup::removeCertAtIndex(
        unsigned                        index)                          // doesn't delete the cert, just 
                                                                                        // removes it from out list
{
        if(index > (mNumCerts - 1)) {
                CssmError::throwMe(CSSMERR_TP_INTERNAL_ERROR);
        }
        TPCertInfo *rtn = mCertInfo[index];
        
        /* removed requested element and compact remaining array */
        unsigned i;
        for(i=index; i<(mNumCerts - 1); i++) {
                mCertInfo[i] = mCertInfo[i+1];
        }
        mNumCerts--;
        return rtn;
}

TPCertInfo *TPCertGroup::firstCert()
{
        if(mNumCerts == 0) {
                /* the caller really should not do this... */
                CssmError::throwMe(CSSMERR_TP_INTERNAL_ERROR);
        }
        else {
                return mCertInfo[0];
        }
}

TPCertInfo *TPCertGroup::lastCert()
{
        if(mNumCerts == 0) {
                return NULL;
        }
        else {
                return mCertInfo[mNumCerts - 1];
        }
}

/* build a CSSM_CERTGROUP corresponding with our mCertInfo */
CSSM_CERTGROUP_PTR TPCertGroup::buildCssmCertGroup()
{
        CSSM_CERTGROUP_PTR cgrp = 
                (CSSM_CERTGROUP_PTR)mAlloc.malloc(sizeof(CSSM_CERTGROUP));
        cgrp->NumCerts = mNumCerts;
        cgrp->CertGroupType = CSSM_CERTGROUP_DATA;
        cgrp->CertType = CSSM_CERT_X_509v3;
        cgrp->CertEncoding = CSSM_CERT_ENCODING_DER; 
        if(mNumCerts == 0) {
                /* legal */
                cgrp->GroupList.CertList = NULL;
                return cgrp;
        }
        cgrp->GroupList.CertList = (CSSM_DATA_PTR)mAlloc.calloc(mNumCerts, 
                sizeof(CSSM_DATA));
        for(unsigned i=0; i<mNumCerts; i++) {
                tpCopyCssmData(mAlloc, mCertInfo[i]->itemData(), 
                        &cgrp->GroupList.CertList[i]);
        }
        return cgrp;
}

/* build a CSSM_TP_APPLE_EVIDENCE_INFO array */
CSSM_TP_APPLE_EVIDENCE_INFO *TPCertGroup::buildCssmEvidenceInfo()
{
        CSSM_TP_APPLE_EVIDENCE_INFO *infoArray;
        
        infoArray = (CSSM_TP_APPLE_EVIDENCE_INFO *)mAlloc.calloc(mNumCerts,
                sizeof(CSSM_TP_APPLE_EVIDENCE_INFO));
        for(unsigned i=0; i<mNumCerts; i++) {
                TPCertInfo *certInfo = mCertInfo[i];
                CSSM_TP_APPLE_EVIDENCE_INFO *evInfo = &infoArray[i];
                
                /* first the booleans */
                if(certInfo->isExpired()) {
                        evInfo->StatusBits |= CSSM_CERT_STATUS_EXPIRED;
                }
                if(certInfo->isNotValidYet()) {
                        evInfo->StatusBits |= CSSM_CERT_STATUS_NOT_VALID_YET;
                }
                if(certInfo->isAnchor()) {
                        tpAnchorDebug("buildCssmEvidenceInfo: flagging IS_IN_ANCHORS");
                        evInfo->StatusBits |= CSSM_CERT_STATUS_IS_IN_ANCHORS;
                }
                if(certInfo->dlDbHandle().DLHandle == 0) {
                        if(certInfo->isFromNet()) {
                                evInfo->StatusBits |= CSSM_CERT_STATUS_IS_FROM_NET;
                        }
                        else if(certInfo->isFromInputCerts()) {
                                evInfo->StatusBits |= CSSM_CERT_STATUS_IS_IN_INPUT_CERTS;
                        }
                }
                /* If trust settings apply to a root, skip verifying the signature */
                bool avoidVerify = false;
                switch(certInfo->trustSettingsResult()) {
                        case kSecTrustSettingsResultTrustRoot:
                        case kSecTrustSettingsResultTrustAsRoot:
                                /* these two can be disambiguated by IS_ROOT */
                                evInfo->StatusBits |= CSSM_CERT_STATUS_TRUST_SETTINGS_TRUST;
                                avoidVerify = true;
                                break;
                        case kSecTrustSettingsResultDeny:
                                evInfo->StatusBits |= CSSM_CERT_STATUS_TRUST_SETTINGS_DENY;
                                avoidVerify = true;
                                break;
                        case kSecTrustSettingsResultUnspecified:
                        case kSecTrustSettingsResultInvalid:
                        default:
                                break;
                }
                if(certInfo->isSelfSigned(avoidVerify)) {
                        evInfo->StatusBits |= CSSM_CERT_STATUS_IS_ROOT;
                }
                if(certInfo->ignoredError()) {
                        evInfo->StatusBits |= CSSM_CERT_STATUS_TRUST_SETTINGS_IGNORED_ERROR;
                }
                unsigned numCodes = certInfo->numStatusCodes();
                if(numCodes) {
                        evInfo->NumStatusCodes = numCodes;
                        evInfo->StatusCodes = (CSSM_RETURN *)mAlloc.calloc(numCodes,
                                sizeof(CSSM_RETURN));
                        for(unsigned j=0; j<numCodes; j++) {
                                evInfo->StatusCodes[j] = (certInfo->statusCodes())[j];
                        }
                }
                if(evInfo->StatusBits & (CSSM_CERT_STATUS_TRUST_SETTINGS_TRUST |
                                                                 CSSM_CERT_STATUS_TRUST_SETTINGS_DENY |
                                                                 CSSM_CERT_STATUS_TRUST_SETTINGS_IGNORED_ERROR)) {
                        /* Something noteworthy happened involving TrustSettings */
                        uint32 whichDomain = 0;
                        switch(certInfo->trustSettingsDomain()) {
                                case kSecTrustSettingsDomainUser:
                                        whichDomain = CSSM_CERT_STATUS_TRUST_SETTINGS_FOUND_USER;
                                        break;
                                case kSecTrustSettingsDomainAdmin:
                                        whichDomain = CSSM_CERT_STATUS_TRUST_SETTINGS_FOUND_ADMIN;
                                        break;
                                case kSecTrustSettingsDomainSystem:
                                        whichDomain = CSSM_CERT_STATUS_TRUST_SETTINGS_FOUND_SYSTEM;
                                        break;
                        }
                        evInfo->StatusBits |= whichDomain;
                }
                evInfo->Index = certInfo->index();
                evInfo->DlDbHandle = certInfo->dlDbHandle();
                evInfo->UniqueRecord = certInfo->uniqueRecord();
        }
        return infoArray;
}
                
/* Given a status for basic construction of a cert group and a status
 * of (optional) policy verification, plus the implicit notBefore/notAfter
 * status in the certs, calculate a global return code. This just 
 * encapsulates a policy for CertGroupConstruct and CertGroupVerify.
 */
CSSM_RETURN TPCertGroup::getReturnCode(
        CSSM_RETURN                                     constructStatus,
        CSSM_RETURN                                     policyStatus,
        CSSM_APPLE_TP_ACTION_FLAGS      actionFlags)
{
        if(constructStatus) {
                /* CSSMERR_TP_NOT_TRUSTED, CSSMERR_TP_INVALID_ANCHOR_CERT, gross errors */
                return constructStatus;
        }

        bool expired = false;
        bool postdated = false;
        bool allowExpiredRoot = (actionFlags & CSSM_TP_ACTION_ALLOW_EXPIRED_ROOT) ?
                true : false;
        bool allowExpired = (actionFlags & CSSM_TP_ACTION_ALLOW_EXPIRED) ? true : false;
        bool allowPostdated = allowExpired; // flag overrides any temporal invalidity
        bool requireRevPerCert = (actionFlags & CSSM_TP_ACTION_REQUIRE_REV_PER_CERT) ?
                true : false;
                
        /* check for expired, not valid yet */
        for(unsigned i=0; i<mNumCerts; i++) {
                TPCertInfo *ci = mCertInfo[i];
                /* 
                 * Note avoidVerify = true for isSelfSigned(); if it were appropriate to 
                 * verify the signature, that would have happened in 
                 * buildCssmEvidenceInfo() at the latest.
                 */
                if(ci->isExpired() &&
                   !(allowExpiredRoot && ci->isSelfSigned(true)) &&             // allowed globally
                    ci->isStatusFatal(CSSMERR_TP_CERT_EXPIRED)) {       // allowed for this cert
                        expired = true;
                }
                if(ci->isNotValidYet() && 
                   ci->isStatusFatal(CSSMERR_TP_CERT_NOT_VALID_YET)) {
                        postdated = true;
                }
        }
        if(expired && !allowExpired) {
                return CSSMERR_TP_CERT_EXPIRED;
        }
        if(postdated && !allowPostdated) {
                return CSSMERR_TP_CERT_NOT_VALID_YET;
        }
        
        /* Check for missing revocation check */
        if(requireRevPerCert) {
                for(unsigned i=0; i<mNumCerts; i++) {
                        TPCertInfo *ci = mCertInfo[i];
                        if(ci->isSelfSigned(true)) {
                                /* revocation check meaningless for a root cert */
                                tpDebug("getReturnCode: ignoring revocation for self-signed cert %d", i);
                                continue;
                        }
                        if(!ci->revokeCheckGood() &&
                           ci->isStatusFatal(CSSMERR_APPLETP_INCOMPLETE_REVOCATION_CHECK)) {
                                tpDebug("getReturnCode: FATAL: revocation check incomplete for cert %d", i);
                                return CSSMERR_APPLETP_INCOMPLETE_REVOCATION_CHECK;
                        }
                        #ifndef NDEBUG
                        else {
                                tpDebug("getReturnCode: revocation check %s for cert %d",
                                        (ci->revokeCheckGood()) ? "GOOD" : "OK", i);
                        }
                        #endif
                }
        }
        return policyStatus;
}

/* set all TPCertInfo.mUsed flags false */
void TPCertGroup::setAllUnused()
{
        for(unsigned dex=0; dex<mNumCerts; dex++) {
                mCertInfo[dex]->used(false);
        }
}

/*
 * See if the specified error status is allowed (return true) or
 * fatal (return false) per each cert's mAllowedErrs[]. Returns
 * true if any cert returns false for its isStatusFatal() call. 
 * The list of errors which can apply to cert-chain-wide allowedErrors
 * is right here; if the incoming error is not in that list, we
 * return false. If the incoming error code is CSSM_OK we return
 * true as a convenience for our callers. 
 */
bool TPCertGroup::isAllowedError(
        CSSM_RETURN     code)
{
        switch(code) {
                case CSSM_OK:
                        return true;
                case CSSMERR_TP_NOT_TRUSTED:
                case CSSMERR_TP_INVALID_ANCHOR_CERT:
                case CSSMERR_TP_VERIFY_ACTION_FAILED:
                case CSSMERR_TP_INVALID_CERT_AUTHORITY:
                case CSSMERR_APPLETP_CS_BAD_CERT_CHAIN_LENGTH:
                case CSSMERR_APPLETP_RS_BAD_CERT_CHAIN_LENGTH:
                        /* continue processing these candidates */
                        break;
                default:
                        /* not a candidate for cert-chain-wide allowedErrors */
                        return false; 
        }

        for(unsigned dex=0; dex<mNumCerts; dex++) {
                if(!mCertInfo[dex]->isStatusFatal(code)) {
                        tpTrustSettingsDbg("TPCertGroup::isAllowedError: allowing for cert %u",
                                dex);
                        return true;
                }
        }

        /* every cert thought this was fatal; it is. */
        return false;
}

/*
 * Determine if we already have the specified cert in this group.
 */
bool TPCertGroup::isInGroup(TPCertInfo &certInfo)
{
        for(unsigned dex=0; dex<mNumCerts; dex++) {
                if(tpCompareCssmData(certInfo.itemData(), mCertInfo[dex]->itemData())) {
                        return true;    
                }
        }
        return false;
}

/* 
 * Encode issuing certs in this group as a PEM-encoded data blob.
 * Caller must free.
 */
void TPCertGroup::encodeIssuers(CSSM_DATA &issuers)
{
        /* FIXME: probably want to rewrite this using pemEncode() from libsecurity_cdsa_utils,
         * since use of Sec* APIs from this layer violates the API reentrancy contract.
         */
        issuers.Data = NULL;
        issuers.Length = 0;
        CFMutableArrayRef certArray = CFArrayCreateMutable(kCFAllocatorDefault,
                0, &kCFTypeArrayCallBacks);
        if(!certArray) {
                return;
        }
        for(unsigned certDex=0; certDex<mNumCerts; certDex++) {
                TPCertInfo *certInfo = certAtIndex(certDex);
                if(!certDex && mNumCerts > 1) {
                        continue; /* don't need the leaf */
                }
                CSSM_DATA *cssmData = (CSSM_DATA*)((certInfo) ? certInfo->itemData() : NULL);
                if(!cssmData || !cssmData->Data || !cssmData->Length) {
                        continue;
                }
                CFDataRef dataRef = CFDataCreateWithBytesNoCopy(kCFAllocatorDefault,
                        (const UInt8 *)cssmData->Data, cssmData->Length,
                        kCFAllocatorNull);
                if(!dataRef) {
                        continue;
                }
                SecCertificateRef certRef = SecCertificateCreateWithData(kCFAllocatorDefault,
                        dataRef);
                if(!certRef) {
                        CFRelease(dataRef);
                        continue;
                }
                CFArrayAppendValue(certArray, certRef);
                CFRelease(certRef);
                CFRelease(dataRef);
        }
        CFDataRef exportedPEMData = NULL;
        OSStatus status = SecItemExport(certArray,
                kSecFormatPEMSequence,
                kSecItemPemArmour,
                NULL,
                &exportedPEMData);
        CFRelease(certArray);

        if(!status)     {
                uint8 *dataPtr = (uint8*)CFDataGetBytePtr(exportedPEMData);
                size_t dataLen = CFDataGetLength(exportedPEMData);
                issuers.Data = (uint8*)malloc(dataLen);
                memmove(issuers.Data, dataPtr, dataLen);
                issuers.Length = dataLen;
                CFRelease(exportedPEMData);
        }
}

/*
 * Search unused incoming certs to find an issuer of specified cert or CRL.
 * WARNING this assumes a valid "used" state for all certs in this group.
 * If partialIssuerKey is true on return, caller must re-verify signature
 * of subject later when sufficient info is available. 
 */
TPCertInfo *TPCertGroup::findIssuerForCertOrCrl(
        const TPClItemInfo &subject,
        bool &partialIssuerKey)
{
        partialIssuerKey = false;
        TPCertInfo *expiredIssuer = NULL;
        
        for(unsigned certDex=0; certDex<mNumCerts; certDex++) {
                TPCertInfo *certInfo = certAtIndex(certDex);
                
                /* has this one already been used in this search? */
                if(certInfo->used()) {
                        continue;
                }
                
                /* subject/issuer names match? */
                if(certInfo->isIssuerOf(subject)) {
                        /* yep, do a sig verify */
                        tpVfyDebug("findIssuerForCertOrCrl issuer/subj match checking sig");
                        CSSM_RETURN crtn = subject.verifyWithIssuer(certInfo);
                        switch(crtn) {
                                case CSSMERR_CSP_APPLE_PUBLIC_KEY_INCOMPLETE:
                                        /* issuer OK, check sig later */
                                        partialIssuerKey = true;
                                        /* and fall thru */
                                case CSSM_OK:
                                        /* 
                                         * Temporal validity check: if we're not already holding an expired
                                         * issuer, and this one's invalid, hold it and keep going. 
                                         */
                                        if((crtn == CSSM_OK) && (expiredIssuer == NULL)) {
                                                if(certInfo->isExpired() || certInfo->isNotValidYet()) {
                                                        tpDebug("findIssuerForCertOrCrl: holding expired cert %p",
                                                                certInfo);
                                                        expiredIssuer = certInfo;
                                                        break;
                                                }
                                        }
                                        /* YES */
                                        certInfo->used(true);
                                        return certInfo;
                                default:
                                        /* just skip this one and keep looking */
                                        tpVfyDebug("findIssuerForCertOrCrl issuer/subj match BAD SIG");
                                        break;
                        }
                }       /* names match */
        }
        if(expiredIssuer != NULL) {
                /* OK, we'll use this one */
                tpDbDebug("findIssuerForCertOrCrl: using expired cert %p", expiredIssuer);
                expiredIssuer->used(true);
                return expiredIssuer;
        }
        
        /* not found */
        return NULL;
}       

/*
 * Construct ordered, verified cert chain from a variety of inputs. 
 * Time validity does not affect the function return or any status, 
 * we always try to find a valid cert to replace an expired or 
 * not-yet-valid cert if we can. Final temporal validity of each 
 * cert must be checked by caller (it's stored in each TPCertInfo 
 * we add to ourself during construction). 
 * 
 * Only possible error returns are:
 *       CSSMERR_TP_CERTIFICATE_CANT_OPERATE : issuer cert was found with a partial
 *                      public key, rendering full verification impossible. 
 *   CSSMERR_TP_INVALID_CERT_AUTHORITY : issuer cert was found with a partial 
 *                      public key and which failed to perform subsequent signature
 *                      verification.
 *
 * Other interesting status is returned via the verifiedToRoot and 
 * verifiedToAnchor flags. 
 *
 * NOTE: is it the caller's responsibility to call setAllUnused() for both 
 * incoming cert groups (inCertGroup and gatheredCerts). We don't do that
 * here because we may call ourself recursively. 
 */
CSSM_RETURN TPCertGroup::buildCertGroup(
        const TPClItemInfo              &subjectItem,   // Cert or CRL
        TPCertGroup                             *inCertGroup,   // optional
        const CSSM_DL_DB_LIST   *dbList,                // optional
        CSSM_CL_HANDLE                  clHand,
        CSSM_CSP_HANDLE                 cspHand,
        const char                              *verifyTime,    // optional, for establishing
                                                                                        //   validity of new TPCertInfos
        /* trusted anchors, optional */
        /* FIXME - maybe this should be a TPCertGroup */
        uint32                                  numAnchorCerts,
        const CSSM_DATA                 *anchorCerts,
        
        /* 
         * Certs to be freed by caller (i.e., TPCertInfo which we allocate
         * as a result of using a cert from anchorCerts or dbList) are added
         * to this group.
         */
        TPCertGroup                             &certsToBeFreed,
        
        /*
         * Other certificates gathered during the course of this operation,
         * currently consisting of certs fetched from DBs and from the net.
         * This is not used when called by AppleTPSession::CertGroupConstructPriv;
         * it's an optimization for the case when we're building a cert group
         * for TPCrlInfo::verifyWithContext - we avoid re-fetching certs from
         * the net which are needed to verify both the subject cert and a CRL.
         * We don't modify this TPCertGroup, we only use certs from it. 
         */
        TPCertGroup                             *gatheredCerts,
        
        /*
         * Indicates that subjectItem is a cert in this cert group.
         * If true, that cert will be tested for "root-ness", including 
         *   -- subject/issuer compare
         *   -- signature self-verify
         *   -- anchor compare
         */
        CSSM_BOOL                               subjectIsInGroup,
        
        /* 
         * CSSM_TP_ACTION_FETCH_CERT_FROM_NET,
         * CSSM_TP_ACTION_TRUST_SETTING,
         * CSSM_TP_ACTION_IMPLICIT_ANCHORS are interesting 
         */
        CSSM_APPLE_TP_ACTION_FLAGS      actionFlags,
        
        /* CSSM_TP_ACTION_TRUST_SETTING parameters */
        const CSSM_OID                  *policyOid,
        const char                              *policyStr,
        uint32                                  policyStrLen,
        SecTrustSettingsKeyUsage leafKeyUse,                            // usage of *first* cert in chain
        
        /* returned */
        CSSM_BOOL                               &verifiedToRoot,                        // end of chain self-verifies
        CSSM_BOOL                               &verifiedToAnchor,                      // end of chain in anchors
        CSSM_BOOL                               &verifiedViaTrustSettings)      // chain ends per User Trust setting
{
        const TPClItemInfo *thisSubject = &subjectItem;
        CSSM_RETURN crtn = CSSM_OK;
        TPCertInfo *issuerCert = NULL;
        unsigned certDex;
        TPCertInfo *anchorInfo = NULL;
        bool foundPartialIssuer = false;
        bool attemptNetworkFetch = false;
        CSSM_BOOL firstSubjectIsInGroup = subjectIsInGroup;
        TPCertInfo *endCert;
        
        tpVfyDebug("buildCertGroup top");
        
        /* possible expired root which we'll only use if we can't find 
         * a better one */
        TPCertInfo *expiredRoot = NULL;
        
        /* and the general case of an expired or not yet valid cert */
        TPCertInfo *expiredIssuer = NULL;
        
        verifiedToRoot = CSSM_FALSE;
        verifiedToAnchor = CSSM_FALSE;
        verifiedViaTrustSettings = CSSM_FALSE;
        
        /*** main loop to seach inCertGroup and dbList ***
         *
         * Exit loop on: 
         *   -- find a root cert in the chain (self-signed)
         *   -- find a non-root cert which is also in the anchors list
         *   -- find a cert which is trusted per Trust Settings (if enabled)
         *   -- memory error
         *   -- or no more certs to add to chain. 
         */
        for(;;) {
                /* 
                 * Top of loop: thisSubject is the item we're trying to verify. 
                 */
                 
                /* is thisSubject a root cert or listed in user trust list?  */
                if(subjectIsInGroup) {
                        TPCertInfo *subjCert = lastCert();
                        assert(subjCert != NULL);
                        
                        if(actionFlags & CSSM_TP_ACTION_TRUST_SETTINGS) {
                                assert(policyOid != NULL);
                                
                                /* 
                                 * Figure out key usage. If this is a leaf cert, the caller - actually
                                 * the per-policy code - inferred the usage. Else it could be for
                                 * verifying a cert or a CRL. 
                                 *
                                 * We want to avoid multiple calls to the effective portion of 
                                 * evaluateTrustSettings(), but a CA cert could be usable for only 
                                 * signing certs and not CRLs. Thus we're evaluating a CA cert, 
                                 * try to evaluate for signing certs *and* CRLs in case we come 
                                 * this way again later when performing CRL verification. If that 
                                 * fails, then retry with just cert signing.
                                 */
                                SecTrustSettingsKeyUsage localKeyUse;
                                bool doRetry = false;
                                if(subjCert == firstCert()) {
                                        /* leaf - use caller's spec */
                                        localKeyUse = leafKeyUse;
                                        /* FIXME - add in CRL if this is cert checking? */
                                }
                                else {
                                        localKeyUse = kSecTrustSettingsKeyUseSignCert | kSecTrustSettingsKeyUseSignRevocation;
                                        /* and if necessary */
                                        doRetry = true; 
                                }
                                /* this lets us avoid searching for the same thing twice when there
                                 * is in fact no entry for it */
                                bool foundEntry = false;
                                bool trustSettingsFound = false;
                                OSStatus ortn = subjCert->evaluateTrustSettings(*policyOid,
                                        policyStr, policyStrLen, localKeyUse, &trustSettingsFound, &foundEntry);
                                if(ortn) {
                                        /* this is only a dire error */
                                        crtn = ortn;
                                        goto final_out;
                                }
                                if(!trustSettingsFound && foundEntry && doRetry) {
                                        tpTrustSettingsDbg("buildCertGroup: retrying evaluateTrustSettings with Cert only");
                                        ortn = subjCert->evaluateTrustSettings(*policyOid,
                                                policyStr, policyStrLen, kSecTrustSettingsKeyUseSignCert, 
                                                &trustSettingsFound, &foundEntry);
                                        if(ortn) {
                                                crtn = ortn;
                                                goto final_out;
                                        }
                                }
                                if(trustSettingsFound) {                                        
                                        switch(subjCert->trustSettingsResult()) {
                                                case kSecTrustSettingsResultInvalid:
                                                        /* should not happen... */
                                                        assert(0);
                                                        crtn = CSSMERR_TP_INTERNAL_ERROR;
                                                        break;
                                                case kSecTrustSettingsResultTrustRoot:
                                                case kSecTrustSettingsResultTrustAsRoot:
                                                        tpTrustSettingsDbg("Trust[As]Root found");
                                                        crtn = CSSM_OK;
                                                        break;
                                                case kSecTrustSettingsResultDeny:
                                                        tpTrustSettingsDbg("TrustResultDeny found");
                                                        crtn = CSSMERR_APPLETP_TRUST_SETTING_DENY;
                                                        break;
                                                case kSecTrustSettingsResultUnspecified:
                                                        /* special case here: this means "keep going, we don't trust or 
                                                         * distrust this cert". Typically used to express allowed errors
                                                         * only. 
                                                         */
                                                        tpTrustSettingsDbg("TrustResultUnspecified found");
                                                        goto post_trust_setting;
                                                default:
                                                        tpTrustSettingsDbg("Unknown TrustResult (%d)", 
                                                                (int)subjCert->trustSettingsResult());
                                                        crtn = CSSMERR_TP_INTERNAL_ERROR;
                                                        break;
                                        }
                                        /* cleanup partial key processing */
                                        verifiedViaTrustSettings = CSSM_TRUE;
                                        goto final_out;
                                }
                        }       /* CSSM_TP_ACTION_TRUST_SETTING */

post_trust_setting:
                        if(subjCert->isSelfSigned()) {
                                /* We're at the end of the chain. */
                                verifiedToRoot = CSSM_TRUE;
                                
                                /*
                                 * Special case if this root is temporally invalid (and it's not
                                 * the leaf): remove it from the outgoing cert group, save it,
                                 * and proceed, looking another (good) root in anchors. 
                                 * There's no way we'll find another good one in this loop.
                                 */
                                if((subjCert->isExpired() || subjCert->isNotValidYet()) && 
                                   (!firstSubjectIsInGroup || (mNumCerts > 1))) {
                                        tpDebug("buildCertGroup: EXPIRED ROOT %p, looking for good one", subjCert);
                                        expiredRoot = subjCert;
                                        if(mNumCerts) {
                                                /* roll back to previous cert */
                                                mNumCerts--;
                                        }
                                        if(mNumCerts == 0) {
                                                /* roll back to caller's initial condition */
                                                thisSubject = &subjectItem;
                                        }
                                        else {
                                                thisSubject = lastCert();
                                        }
                                }
                                break;          /* out of main loop */
                        }       /* root */
                        
                        /*
                         * If this non-root cert is in the provided anchors list,
                         * we can stop building the chain at this point.
                         *
                         * If this cert is a leaf, the chain ends in an anchor, but if it's
                         * also temporally invalid, we can't do anything further. However,
                         * if it's not a leaf, then we need to roll back the chain to a
                         * point just before this cert, so Case 1 will subsequently find
                         * the anchor (and handle the anchor correctly if it's expired.)
                         */
                        if(numAnchorCerts && anchorCerts) {
                                bool foundNonRootAnchor = false;
                                for(certDex=0; certDex<numAnchorCerts; certDex++) {
                                        if(tp_CompareCerts(subjCert->itemData(), &anchorCerts[certDex])) {
                                                foundNonRootAnchor = true;
                                                /* if it's not the leaf, remove it from the outgoing cert group. */
                                                if(!firstSubjectIsInGroup || (mNumCerts > 1)) {
                                                        if(mNumCerts) {
                                                                /* roll back to previous cert */
                                                                mNumCerts--;
                                                        }
                                                        if(mNumCerts == 0) {
                                                                /* roll back to caller's initial condition */
                                                                thisSubject = &subjectItem;
                                                        }
                                                        else {
                                                                thisSubject = lastCert();
                                                        }
                                                        tpAnchorDebug("buildCertGroup: CA cert in input AND anchors");
                                                } /* not leaf */
                                                else {
                                                        if(subjCert->isExpired() || subjCert->isNotValidYet()) {
                                                                crtn = CSSM_CERT_STATUS_EXPIRED;
                                                        } else {
                                                                crtn = CSSM_OK;
                                                        }
                                                        subjCert->isAnchor(true);
                                                        verifiedToAnchor = CSSM_TRUE;
                                                        tpAnchorDebug("buildCertGroup: leaf cert in input AND anchors");
                                                } /* leaf */
                                                break;  /* out of anchor-checking loop */
                                        }
                                }
                                if(foundNonRootAnchor) {
                                        break; /* out of main loop */
                                }
                        } /* non-root */
                        
                }       /* subjectIsInGroup */
                
                /* 
                 * Search unused incoming certs to find an issuer.
                 * Both cert groups are optional.
                 * We'll add issuer to outCertGroup below.
                 * If we find  a cert that's expired or not yet valid, we hold on to it
                 * and look for a better one. If we don't find it here we drop back to the 
                 * expired one at the end of the loop. If that expired cert is a root 
                 * cert, we'll use the expiredRoot mechanism (see above) to roll back and 
                 * see if we can find a good root in the incoming anchors. 
                 */
                if(inCertGroup != NULL) {
                        bool partial = false;
                        issuerCert = inCertGroup->findIssuerForCertOrCrl(*thisSubject, 
                                partial);
                        if(issuerCert) {
                                issuerCert->isFromInputCerts(true);
                                if(partial) {
                                        /* deal with this later */
                                        foundPartialIssuer = true;
                                        tpDebug("buildCertGroup: PARTIAL Cert FOUND in inCertGroup");           
                                }
                                else {
                                        tpDebug("buildCertGroup: Cert FOUND in inCertGroup");           
                                }
                        }
                }
                if(issuerCert != NULL) {
                        if(issuerCert->isExpired() || issuerCert->isNotValidYet()) {
                                if(expiredIssuer == NULL) {
                                        tpDebug("buildCertGroup: saving expired cert %p (1)", issuerCert);              
                                        expiredIssuer = issuerCert;
                                        issuerCert = NULL;
                                }
                                /* else we already have an expired issuer candidate */
                        }
                        else {
                                /* unconditionally done with possible expiredIssuer */
                                #ifndef NDEBUG
                                if(expiredIssuer != NULL) {
                                        tpDebug("buildCertGroup: DISCARDING expired cert %p (1)", expiredIssuer);
                                }
                                #endif
                                expiredIssuer = NULL;
                        }
                }
                
                if((issuerCert == NULL) && (gatheredCerts != NULL)) {
                        bool partial = false;
                        issuerCert = gatheredCerts->findIssuerForCertOrCrl(*thisSubject,
                                partial);
                        if(issuerCert) {
                                if(partial) {
                                        /* deal with this later */
                                        foundPartialIssuer = true;
                                        tpDebug("buildCertGroup: PARTIAL Cert FOUND in gatheredCerts");         
                                }
                                else {
                                        tpDebug("buildCertGroup: Cert FOUND in gatheredCerts");
                                }
                        }
                }
                
                if(issuerCert != NULL) {
                        if(issuerCert->isExpired() || issuerCert->isNotValidYet()) {
                                if(expiredIssuer == NULL) {
                                        tpDebug("buildCertGroup: saving expired cert %p (2)", issuerCert);              
                                        expiredIssuer = issuerCert;
                                        issuerCert = NULL;
                                }
                                /* else we already have an expired issuer candidate */
                        }
                        else {
                                /* unconditionally done with possible expiredIssuer */
                                #ifndef NDEBUG
                                if(expiredIssuer != NULL) {
                                        tpDebug("buildCertGroup: DISCARDING expired cert %p (2)", expiredIssuer);
                                }
                                #endif
                                expiredIssuer = NULL;
                        }
                }

                if((issuerCert == NULL) && (dbList != NULL)) {
                        /* Issuer not in incoming cert group or gathered certs. Search DBList. */
                        bool partial = false;
                        try {
                                issuerCert = tpDbFindIssuerCert(mAlloc,
                                        clHand,
                                        cspHand,
                                        thisSubject,
                                        dbList,
                                        verifyTime,
                                        partial);
                        }
                        catch (...) {}

                        if(issuerCert) {
                                /* unconditionally done with possible expiredIssuer */
                                #ifndef NDEBUG
                                if(expiredIssuer != NULL) {
                                        tpDebug("buildCertGroup: DISCARDING expired cert %p (3)", expiredIssuer);
                                }
                                #endif
                                expiredIssuer = NULL;

                                /*
                                 * Handle Radar 4566041, endless loop of cross-signed certs.
                                 * This can only happen when fetching certs from a DLDB or 
                                 * from the net; we prevent that from happening when the certs
                                 * are in inCertGroup or gatheredCerts by keeping track of those
                                 * certs' mUsed state.
                                 */
                                if(isInGroup(*issuerCert)) {
                                        tpDebug("buildCertGroup: Multiple instances of cert");
                                        delete issuerCert;
                                        issuerCert = NULL;
                                }
                                else {
                                        /* caller must free */
                                        certsToBeFreed.appendCert(issuerCert);
                                        if(partial) {
                                                /* deal with this later */
                                                foundPartialIssuer = true;
                                                tpDebug("buildCertGroup: PARTIAL Cert FOUND in dbList");                
                                        }
                                        else {
                                                tpDebug("buildCertGroup: Cert FOUND in dbList");
                                        }
                                }
                        }
                }       /*  searching DLDB list */
                
                /*
                 * Note: we don't handle an expired cert returned from tpDbFindIssuerCert()
                 * in any special way like we do with findIssuerForCertOrCrl(). 
                 * tpDbFindIssuerCert() does its best to give us a temporally valid cert; if
                 * it returns an expired cert (or, if findIssuerForCertOrCrl() gave us an
                 * expired cert and tpDbFindIssuerCert() could not do any better), that's all 
                 * we have to work with at this point. We'll go back to the top of the loop 
                 * and apply trust settings if enabled; if an expired cert is trusted per 
                 * Trust Settings, we're done. (Note that anchors are fetched from a DLDB 
                 * when Trust Settings are enabled, so even if two roots with the same key 
                 * and subject name are in DLDBs, and one of them is expired, we'll have the 
                 * good one at this time because of tpDbFindIssuerCert()'s ability to find 
                 * the best cert.) 
                 * 
                 * If Trust Settings are not enabled, and we have an expired root at this 
                 * point, the expiredRoot mechanism is used to roll back and search for 
                 * an anchor that verifies the last good cert. 
                 */
                 
                if((issuerCert == NULL) &&                      /* tpDbFindIssuerCert() hasn't found one and
                                                                                         * we don't have a good one */
                   (expiredIssuer != NULL)) {           /* but we have an expired candidate */
                        /* 
                         * OK, we'll take the expired issuer. 
                         * Note we don't have to free expiredIssuer if we found a good one since
                         * expiredIssuer can only come from inCertGroup or gatheredCerts (not from 
                         * dbList).
                         */
                        tpDebug("buildCertGroup: USING expired cert %p", expiredIssuer);
                        issuerCert = expiredIssuer;
                        expiredIssuer = NULL;
                }
                if(issuerCert == NULL) {
                        /* end of search, broken chain */
                        break;
                }
                
                /*
                 * One way or the other, we've found a cert which verifies subjectCert.
                 * Add the issuer to outCertGroup and make it the new thisSubject for
                 * the next pass.
                 */
                appendCert(issuerCert);
                thisSubject = issuerCert;
                subjectIsInGroup = CSSM_TRUE;
                issuerCert = NULL;
        }       /* main loop */
        
        /* 
         * This can be NULL if we're evaluating a CRL (and we haven't 
         * gotten very far).
         */
        endCert = lastCert();

        /* 
         * This, on the other hand, is always valid. It could be a CRL.
         */
        assert(thisSubject != NULL);
        
        if( (actionFlags & CSSM_TP_ACTION_IMPLICIT_ANCHORS) &&
                ( (endCert && endCert->isSelfSigned()) || expiredRoot) ) {
                /* 
                 * Caller will be satisfied with this; skip further anchor processing.
                 */
                tpAnchorDebug("buildCertGroup: found IMPLICIT anchor");
                goto post_anchor;
        }
        if(numAnchorCerts == 0) {
                /* we're probably done */
                goto post_anchor;
        }
        assert(anchorCerts != NULL);
        
        /*** anchor cert handling ***/
        
        /* 
         * Case 1: If thisSubject is not a root cert, try to validate with incoming anchor certs.
         */
        expiredIssuer = NULL;
        if(!(endCert && endCert->isSelfSigned())) {
                for(certDex=0; certDex<numAnchorCerts; certDex++) {
                        
                        try {
                                anchorInfo = new TPCertInfo(clHand,
                                        cspHand,
                                        &anchorCerts[certDex], 
                                        TIC_NoCopy, 
                                        verifyTime);
                        }
                        catch(...) {
                                /* bad anchor cert - ignore it */
                                anchorInfo = NULL;
                                continue;
                        }
                        
                        /* 
                         * We must subsequently delete anchorInfo one way or the other.
                         * If we add it to tpCertGroup, we also add it to certsToBeFreed.
                         * Otherwise we delete it.
                         */
                        if(!anchorInfo->isIssuerOf(*thisSubject)) {
                                /* not this anchor */
                                tpAnchorDebug("buildCertGroup anchor not issuer");
                                delete anchorInfo;
                                anchorInfo = NULL;
                                continue;
                        }

                        crtn = thisSubject->verifyWithIssuer(anchorInfo);
                        
                        if(crtn == CSSM_OK) {
                                if(anchorInfo->isExpired() || anchorInfo->isNotValidYet()) {
                                        if(expiredIssuer == NULL) {
                                                /* 
                                                 * Hang on to this one; keep looking for a better one. 
                                                 */
                                                tpDebug("buildCertGroup: saving expired anchor %p", anchorInfo);                
                                                expiredIssuer = anchorInfo;
                                                /* flag this condition for the switch below */
                                                crtn = CSSM_CERT_STATUS_EXPIRED;
                                                expiredIssuer->isAnchor(true);
                                                assert(!anchorInfo->isFromInputCerts());
                                                expiredIssuer->index(certDex);
                                                certsToBeFreed.appendCert(expiredIssuer);
                                        }
                                        /* else we already have an expired candidate anchor */
                                }
                                else {
                                        /* 
                                         * Done with possible expiredIssuer. We don't delete it, since we already added 
                                         * it to certsToBeFreed, above.
                                         */
                                        if(expiredIssuer != NULL) {
                                                tpDebug("buildCertGroup: DISCARDING expired anchor %p", expiredIssuer);
                                                expiredIssuer = NULL;
                                        }
                                }
                        }
                        
                        switch(crtn) {
                                case CSSMERR_CSP_APPLE_PUBLIC_KEY_INCOMPLETE:
                                        /*
                                         * A bit of a corner case. Found an issuer in AnchorCerts, but
                                         * we can't do a signature verify since the issuer has a partial
                                         * public key. Proceed but return 
                                         * CSSMERR_TP_CERTIFICATE_CANT_OPERATE.
                                         */
                                        if(anchorInfo->addStatusCode(CSSMERR_TP_CERTIFICATE_CANT_OPERATE)) {
                                                foundPartialIssuer = true;
                                                crtn = CSSMERR_TP_CERTIFICATE_CANT_OPERATE;
                                        }
                                        else {
                                                /* ignore */
                                                crtn = CSSM_OK;
                                        }
                                         /* drop thru */
                                case CSSM_OK:
                                        /*  A fully successful return. */
                                        verifiedToAnchor = CSSM_TRUE;
                                        if(anchorInfo->isSelfSigned()) {
                                                verifiedToRoot = CSSM_TRUE;     
                                        }
                                        
                                        /*
                                         * Add this anchor cert to the output group 
                                         * and to certsToBeFreed.
                                         */
                                        appendCert(anchorInfo);
                                        anchorInfo->isAnchor(true);
                                        assert(!anchorInfo->isFromInputCerts());
                                        anchorInfo->index(certDex);
                                        certsToBeFreed.appendCert(anchorInfo);
                                        tpDebug("buildCertGroup: Cert FOUND by signer in AnchorList");  
                                        tpAnchorDebug("buildCertGroup: Cert FOUND by signer in AnchorList");
                                        /* one more thing: partial public key processing needed? */
                                        if(foundPartialIssuer) {
                                                return verifyWithPartialKeys(subjectItem);
                                        }
                                        else {
                                                return crtn;
                                        }
                                        
                                default:
                                        /* continue to next anchor */
                                        if(crtn != CSSM_CERT_STATUS_EXPIRED) {
                                                /* Expired means we're saving it in expiredIssuer */
                                                tpVfyDebug("buildCertGroup found issuer in anchor, BAD SIG");
                                                delete anchorInfo;
                                        }
                                        anchorInfo = NULL;
                                        break;
                        }
                }       /* for each anchor */
        }       /* thisSubject not a root cert */
        
        /*
         * Case 2: Check whether endCert is present in anchor certs.
         *
         * Also used to validate an expiredRoot that we pulled off the chain in 
         * hopes of finding something better (which, if we're here, we haven't done). 
         *
         * Note that the main loop above did the actual root self-verify test.
         */
        if(endCert || expiredRoot) {
                
                TPCertInfo *theRoot;
                if(expiredRoot) {
                        /* this is NOT in our outgoing cert group (yet) */
                        theRoot = expiredRoot;
                }
                else {
                        theRoot = endCert;
                }
                /* see if that root cert is identical to one of the anchor certs */
                for(certDex=0; certDex<numAnchorCerts; certDex++) {
                        if(tp_CompareCerts(theRoot->itemData(), &anchorCerts[certDex])) {
                                /* one fully successful return */
                                tpAnchorDebug("buildCertGroup: end cert in input AND anchors");
                                verifiedToAnchor = CSSM_TRUE;
                                theRoot->isAnchor(true);
                                if(!theRoot->isFromInputCerts()) {
                                        /* Don't override index into input certs */
                                        theRoot->index(certDex);
                                }
                                if(expiredRoot) {
                                        /* verified to anchor but caller will see 
                                         * CSSMERR_TP_CERT_EXPIRED */
                                        appendCert(expiredRoot);
                                }
                                /* one more thing: partial public key processing needed? */
                                if(foundPartialIssuer) {
                                        return verifyWithPartialKeys(subjectItem);
                                }
                                else {
                                        return CSSM_OK;
                                }
                        }
                }
                tpAnchorDebug("buildCertGroup: end cert in input, NOT anchors");
                
                if(!expiredRoot && endCert->isSelfSigned()) {
                        /* verified to a root cert which is not an anchor */
                        /* Generally maps to CSSMERR_TP_INVALID_ANCHOR_CERT by caller */
                        /* one more thing: partial public key processing needed? */
                        if(foundPartialIssuer) {
                                return verifyWithPartialKeys(subjectItem);
                        }
                        else {
                                return CSSM_OK;
                        }
                }
                /* else try finding a good anchor */
        }

        /* regardless of anchor search status... */
        crtn = CSSM_OK;
        if(!verifiedToAnchor && (expiredIssuer != NULL)) {
                /* expiredIssuer here is always an anchor */
                tpDebug("buildCertGroup: accepting expired anchor %p", expiredIssuer);
                appendCert(expiredIssuer);
                verifiedToAnchor = CSSM_TRUE;
                if(expiredIssuer->isSelfSigned()) {
                        verifiedToRoot = CSSM_TRUE;     
                }
                /* no matter what, we don't want this one */
                expiredRoot = NULL;
        }
post_anchor:
        if(expiredRoot) {
                /*
                 * One remaining special case: expiredRoot found in input certs, but 
                 * no luck resolving the problem with the anchors. Go ahead and (re-)append
                 * the expired root and return.
                 */
                tpDebug("buildCertGroup: accepting EXPIRED root");
                appendCert(expiredRoot);
                if(foundPartialIssuer) {
                        return verifyWithPartialKeys(subjectItem);
                }
                else {
                        return CSSM_OK;
                }
        }

        /* If we get here, determine if fetching the issuer from the network
         * should be attempted: <rdar://6113890&7419584&7422356>
         */
        attemptNetworkFetch = (actionFlags & CSSM_TP_ACTION_FETCH_CERT_FROM_NET);
        if( (!dbList || (dbList->NumHandles == 0)) &&
                 (!anchorCerts || (numAnchorCerts == 0)) ) {
                /* DB list is empty *and* anchors are empty; there is no point in going
                 * out to the network, since we cannot build a chain to a trusted root.
                 * (This can occur when the caller wants to evaluate a single certificate
                 * without trying to build the chain, e.g. to check its key usage.)
                 */
                attemptNetworkFetch = false;
        }
        
        /* 
         * If we haven't verified to a root, and net fetch of certs is enabled,
         * try to get the issuer of the last cert in the chain from the net.
         * If that succeeds, then call ourself recursively to perform the 
         * whole search again (including comparing to or verifying against
         * anchor certs).
         */
        if(!verifiedToRoot && !verifiedToAnchor &&
                (endCert != NULL) && attemptNetworkFetch) {
                TPCertInfo *issuer = NULL;
                CSSM_RETURN cr = tpFetchIssuerFromNet(*endCert,
                        clHand,
                        cspHand,
                        verifyTime,
                        issuer);
                switch(cr) {
                        case CSSMERR_TP_CERTGROUP_INCOMPLETE:
                                /* no issuerAltName, no reason to log this */
                                break;
                        default:
                                /* gross error */
                                endCert->addStatusCode(cr);
                                break;
                        case CSSMERR_CSP_APPLE_PUBLIC_KEY_INCOMPLETE:
                                /* use this one but re-verify later */
                                foundPartialIssuer = true;
                                /* and drop thru */
                        case CSSM_OK:
                                if (!issuer)
                                        break;
                                tpDebug("buildCertGroup: Cert FOUND from Net; recursing");

                                if(isInGroup(*issuer)) {
                                        tpDebug("buildCertGroup: Multiple instances of cert from net");
                                        delete issuer;
                                        issuer = NULL;
                                        crtn = CSSMERR_TP_CERTGROUP_INCOMPLETE;
                                        break;
                                }
                                        
                                /* add this fetched cert to constructed group */
                                appendCert(issuer);
                                issuer->isFromNet(true);
                                certsToBeFreed.appendCert(issuer);
                                
                                /* and go again */
                                cr = buildCertGroup(*issuer,
                                        inCertGroup,
                                        dbList,
                                        clHand,
                                        cspHand,
                                        verifyTime,
                                        numAnchorCerts,
                                        anchorCerts,
                                        certsToBeFreed,
                                        gatheredCerts,
                                        CSSM_TRUE,              // subjectIsInGroup     
                                        actionFlags,
                                        policyOid,
                                        policyStr,
                                        policyStrLen,
                                        leafKeyUse,             // actually don't care since the leaf will not
                                                                        // be evaluated
                                        verifiedToRoot,
                                        verifiedToAnchor,
                                        verifiedViaTrustSettings);
                                if(cr) {
                                        return cr;
                                }
                                
                                /* one more thing: partial public key processing needed? */
                                if(foundPartialIssuer) {
                                        return verifyWithPartialKeys(subjectItem);
                                }
                                else {
                                        return CSSM_OK;
                                }
                }
        }
final_out:
        /* regardless of outcome, check for partial keys to log per-cert status */
        CSSM_RETURN partRtn = CSSM_OK;
        if(foundPartialIssuer) {
                partRtn = verifyWithPartialKeys(subjectItem);
        }
        if(crtn) {
                return crtn;
        }
        else {
                return partRtn;
        }
}

/* 
 * Called from buildCertGroup as final processing of a constructed
 * group when CSSMERR_CSP_APPLE_PUBLIC_KEY_INCOMPLETE has been
 * detected. Perform partial public key processing.
 *
 * We don't have to verify every element, just the ones whose
 * issuers have partial public keys.
 *
 * Returns:
 *       CSSMERR_TP_CERTIFICATE_CANT_OPERATE in the case of an issuer cert 
 *              with a partial public key which can't be completed.
 *       CSSMERR_TP_INVALID_CERT_AUTHORITY if sig verify failed with 
 *              a (supposedly) completed partial key
 */
CSSM_RETURN TPCertGroup::verifyWithPartialKeys(
        const TPClItemInfo      &subjectItem)           // Cert or CRL
{
        TPCertInfo *lastFullKeyCert = NULL;
        tpDebug("verifyWithPartialKeys top");
        
        /* start from the end - it's easier */
        for(int dex=mNumCerts-1; dex >= 0; dex--) {
                TPCertInfo *thisCert = mCertInfo[dex];
                
                /*
                 * If this is the start of the cert chain, and it's not being
                 * used to verify subjectItem, then we're done.
                 */
                if(dex == 0) {
                        if((void *)thisCert == (void *)&subjectItem) {
                                tpDebug("verifyWithPartialKeys: success at leaf cert");
                                return CSSM_OK;
                        }
                }
                if(!thisCert->hasPartialKey()) {
                        /* 
                         * Good to know. Record this and move on.
                         */
                        lastFullKeyCert = thisCert;
                        tpDebug("full key cert found at index %d", dex);
                        continue;
                }
                if(lastFullKeyCert == NULL) {
                        /*
                         * No full keys between here and the end!
                         */
                        tpDebug("UNCOMPLETABLE cert at index %d", dex);
                        if(thisCert->addStatusCode(CSSMERR_TP_CERTIFICATE_CANT_OPERATE)) {
                                return CSSMERR_TP_CERTIFICATE_CANT_OPERATE;
                        }
                        else {
                                break;
                        }
                }
                
                /* do the verify - of next cert in chain or of subjectItem */
                const TPClItemInfo *subject;
                if(dex == 0) {
                        subject = &subjectItem;
                        tpDebug("...verifying subject item with partial cert 0");
                }
                else {
                        subject = mCertInfo[dex - 1];
                        tpDebug("...verifying with partial cert %d", dex);
                }
                CSSM_RETURN crtn = subject->verifyWithIssuer(thisCert, 
                        lastFullKeyCert);
                if(crtn) {
                        tpDebug("CERT VERIFY ERROR with partial cert at index %d", dex);
                        if(thisCert->addStatusCode(CSSMERR_TP_CERTIFICATE_CANT_OPERATE)) {
                                return CSSMERR_TP_INVALID_CERT_AUTHORITY;
                        }
                        else {
                                break;
                        }
                }
        }
        
        /* we just verified subjectItem - right?  */
        assert((void *)mCertInfo[0] != (void *)&subjectItem);
        tpDebug("verifyWithPartialKeys: success at subjectItem");
        return CSSM_OK;
}

/* 
 * Free records obtained from DBs. Called when these records are not going to 
 * be passed to caller of CertGroupConstruct or CertGroupVerify.
 */
void TPCertGroup::freeDbRecords()
{
        for(unsigned dex=0; dex<mNumCerts; dex++) {
                TPCertInfo *certInfo = mCertInfo[dex];
                certInfo->freeUniqueRecord();
        }
}