/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
 * pkix_defaultcrlchecker.c
 *
 * Functions for default CRL Checkers
 *
 */
#include "pkix.h"
#include "pkix_crlchecker.h"
#include "pkix_tools.h"

/* --Private-CRLChecker-Data-and-Types------------------------------- */

typedef struct pkix_CrlCheckerStruct {
    /* RevocationMethod is the super class of CrlChecker. */
    pkix_RevocationMethod method;
    PKIX_List *certStores; /* list of CertStore */
    PKIX_PL_VerifyCallback crlVerifyFn;
} pkix_CrlChecker;


/* --Private-CRLChecker-Functions----------------------------------- */

/*
 * FUNCTION: pkix_CrlCheckerstate_Destroy
 * (see comments for PKIX_PL_DestructorCallback in pkix_pl_system.h)
 */
static PKIX_Error *
pkix_CrlChecker_Destroy(
        PKIX_PL_Object *object,
        void *plContext)
{
        pkix_CrlChecker *state = NULL;

        PKIX_ENTER(CRLCHECKER, "pkix_CrlChecker_Destroy");
        PKIX_NULLCHECK_ONE(object);

        /* Check that this object is a default CRL checker state */
        PKIX_CHECK(
            pkix_CheckType(object, PKIX_CRLCHECKER_TYPE, plContext),
            PKIX_OBJECTNOTCRLCHECKER);

        state = (pkix_CrlChecker *)object;

        PKIX_DECREF(state->certStores);

cleanup:

        PKIX_RETURN(CRLCHECKER);
}

/*
 * FUNCTION: pkix_CrlChecker_RegisterSelf
 *
 * DESCRIPTION:
 *  Registers PKIX_CRLCHECKER_TYPE and its related functions
 *  with systemClasses[]
 *
 * THREAD SAFETY:
 *  Not Thread Safe (see Thread Safety Definitions in Programmer's Guide)
 *
 *  Since this function is only called by PKIX_PL_Initialize, which should
 *  only be called once, it is acceptable that this function is not
 *  thread-safe.
 */
PKIX_Error *
pkix_CrlChecker_RegisterSelf(void *plContext)
{
        extern pkix_ClassTable_Entry systemClasses[PKIX_NUMTYPES];
        pkix_ClassTable_Entry* entry = &systemClasses[PKIX_CRLCHECKER_TYPE];

        PKIX_ENTER(CRLCHECKER, "pkix_CrlChecker_RegisterSelf");

        entry->description = "CRLChecker";
        entry->typeObjectSize = sizeof(pkix_CrlChecker);
        entry->destructor = pkix_CrlChecker_Destroy;

        PKIX_RETURN(CRLCHECKER);
}

/*
 * FUNCTION: pkix_CrlChecker_Create
 *
 * DESCRIPTION:
 *  Allocate and initialize CRLChecker state data.
 *
 * PARAMETERS
 *  "certStores"
 *      Address of CertStore List to be stored in state. Must be non-NULL.
 *  "testDate"
 *      Address of PKIX_PL_Date to be checked. May be NULL.
 *  "trustedPubKey"
 *      Trusted Anchor Public Key for verifying first Cert in the chain.
 *      Must be non-NULL.
 *  "certsRemaining"
 *      Number of certificates remaining in the chain.
 *  "nistCRLPolicyEnabled"
 *      If enabled, enforce nist crl policy.
 *  "pChecker"
 *      Address of CRLChecker that is returned. Must be non-NULL.
 *  "plContext"
 *      Platform-specific context pointer.
 *
 * THREAD SAFETY:
 *  Thread Safe (see Thread Safety Definitions in Programmer's Guide)
 *
 * RETURNS:
 *  Returns NULL if the function succeeds.
 *  Returns a DefaultCrlChecker Error if the function fails in a
 *  non-fatal way.
 *  Returns a Fatal Error
 */
PKIX_Error *
pkix_CrlChecker_Create(PKIX_RevocationMethodType methodType,
                       PKIX_UInt32 flags,
                       PKIX_UInt32 priority,
                       pkix_LocalRevocationCheckFn localRevChecker,
                       pkix_ExternalRevocationCheckFn externalRevChecker,
                       PKIX_List *certStores,
                       PKIX_PL_VerifyCallback crlVerifyFn,
                       pkix_RevocationMethod **pChecker,
                       void *plContext)
{
        pkix_CrlChecker *crlChecker = NULL;
        
        PKIX_ENTER(CRLCHECKER, "pkix_CrlChecker_Create");
        PKIX_NULLCHECK_TWO(certStores, pChecker);

        PKIX_CHECK(PKIX_PL_Object_Alloc
                    (PKIX_CRLCHECKER_TYPE,
                    sizeof (pkix_CrlChecker),
                    (PKIX_PL_Object **)&crlChecker,
                    plContext),
                    PKIX_COULDNOTCREATECRLCHECKEROBJECT);

        pkixErrorResult = pkix_RevocationMethod_Init(
            (pkix_RevocationMethod*)crlChecker, methodType, flags,  priority,
            localRevChecker, externalRevChecker, plContext);
        if (pkixErrorResult) {
            goto cleanup;
        }

        /* Initialize fields */
        PKIX_INCREF(certStores);
        crlChecker->certStores = certStores;

        crlChecker->crlVerifyFn = crlVerifyFn;
        *pChecker = (pkix_RevocationMethod*)crlChecker;
        crlChecker = NULL;

cleanup:
        PKIX_DECREF(crlChecker);

        PKIX_RETURN(CRLCHECKER);
}

/* --Private-CRLChecker-Functions------------------------------------ */

/*
 * FUNCTION: pkix_CrlChecker_CheckLocal
 *
 * DESCRIPTION:
 *  Check if the Cert has been revoked based the CRLs data.  This function
 *  maintains the checker state to be current.
 *
 * PARAMETERS
 *  "checker"
 *      Address of CertChainChecker which has the state data.
 *      Must be non-NULL.
 *  "cert"
 *      Address of Certificate that is to be validated. Must be non-NULL.
 *  "unreslvdCrtExts"
 *      A List OIDs. Not **yet** used in this checker function.
 *  "plContext"
 *      Platform-specific context pointer.
 *
 * THREAD SAFETY:
 *  Not Thread Safe
 *      (see Thread Safety Definitions in Programmer's Guide)
 *
 * RETURNS:
 *  Returns NULL if the function succeeds.
 *  Returns a CertChainChecker Error if the function fails in a non-fatal way.
 *  Returns a Fatal Error
 */
PKIX_Error *
pkix_CrlChecker_CheckLocal(
        PKIX_PL_Cert *cert,
        PKIX_PL_Cert *issuer,
        PKIX_PL_Date *date,
        pkix_RevocationMethod *checkerObject,
        PKIX_ProcessingParams *procParams,
        PKIX_UInt32 methodFlags,
        PKIX_Boolean chainVerificationState,
        PKIX_RevocationStatus *pRevStatus,
        CERTCRLEntryReasonCode *pReasonCode,
        void *plContext)
{
    PKIX_CertStore_CheckRevokationByCrlCallback storeCheckRevocationFn;
    PKIX_CertStore *certStore = NULL;
    pkix_CrlChecker *state = NULL;
    PKIX_UInt32 crlStoreIndex = 0;
    PKIX_UInt32 numCrlStores = 0;
    PKIX_Boolean storeIsLocal = PKIX_FALSE;
    PKIX_RevocationStatus revStatus = PKIX_RevStatus_NoInfo;

    PKIX_ENTER(CERTCHAINCHECKER, "pkix_CrlChecker_CheckLocal");
    PKIX_NULLCHECK_FOUR(cert, issuer, checkerObject, checkerObject);
    
    state = (pkix_CrlChecker*)checkerObject;

    PKIX_CHECK(
        PKIX_List_GetLength(state->certStores, &numCrlStores, plContext),
        PKIX_LISTGETLENGTHFAILED);

    for (;crlStoreIndex < numCrlStores;crlStoreIndex++) {
        PKIX_CHECK(
            PKIX_List_GetItem(state->certStores, crlStoreIndex,
                              (PKIX_PL_Object **)&certStore,
                              plContext),
            PKIX_LISTGETITEMFAILED);
        
        PKIX_CHECK(
            PKIX_CertStore_GetLocalFlag(certStore, &storeIsLocal,
                                        plContext),
            PKIX_CERTSTOREGETLOCALFLAGFAILED);
        if (storeIsLocal) {
            PKIX_CHECK(
                PKIX_CertStore_GetCrlCheckerFn(certStore,
                                               &storeCheckRevocationFn,
                                               plContext),
                PKIX_CERTSTOREGETCHECKREVBYCRLFAILED);

            if (storeCheckRevocationFn) {
                PKIX_CHECK(
                    (*storeCheckRevocationFn)(certStore, cert, issuer,
                                         /* delay sig check if building
                                          * a chain by not specifying the time*/
                                          chainVerificationState ? date : NULL,
                                         /* crl downloading is not done. */
                                          PKIX_FALSE,   
                                          pReasonCode, &revStatus, plContext),
                    PKIX_CERTSTORECRLCHECKFAILED);
                if (revStatus == PKIX_RevStatus_Revoked) {
                    break;
                }
            }
        }
        PKIX_DECREF(certStore);
    } /* while */

cleanup:
    *pRevStatus = revStatus;
    PKIX_DECREF(certStore);

    PKIX_RETURN(CERTCHAINCHECKER);
}

/*
 * FUNCTION: pkix_CrlChecker_CheckRemote
 *
 * DESCRIPTION:
 *  Check if the Cert has been revoked based the CRLs data.  This function
 *  maintains the checker state to be current.
 *
 * PARAMETERS
 *  "checker"
 *      Address of CertChainChecker which has the state data.
 *      Must be non-NULL.
 *  "cert"
 *      Address of Certificate that is to be validated. Must be non-NULL.
 *  "unreslvdCrtExts"
 *      A List OIDs. Not **yet** used in this checker function.
 *  "plContext"
 *      Platform-specific context pointer.
 *
 * THREAD SAFETY:
 *  Not Thread Safe
 *      (see Thread Safety Definitions in Programmer's Guide)
 *
 * RETURNS:
 *  Returns NULL if the function succeeds.
 *  Returns a CertChainChecker Error if the function fails in a non-fatal way.
 *  Returns a Fatal Error
 */
PKIX_Error *
pkix_CrlChecker_CheckExternal(
        PKIX_PL_Cert *cert,
        PKIX_PL_Cert *issuer,
        PKIX_PL_Date *date,
        pkix_RevocationMethod *checkerObject,
        PKIX_ProcessingParams *procParams,
        PKIX_UInt32 methodFlags,
        PKIX_RevocationStatus *pRevStatus,
        CERTCRLEntryReasonCode *pReasonCode,
        void **pNBIOContext,
        void *plContext)
{
    PKIX_CertStore_CheckRevokationByCrlCallback storeCheckRevocationFn = NULL;
    PKIX_CertStore_ImportCrlCallback storeImportCrlFn = NULL;
    PKIX_RevocationStatus revStatus = PKIX_RevStatus_NoInfo;
    PKIX_CertStore *certStore = NULL;
    PKIX_CertStore *localStore = NULL;
    PKIX_CRLSelector *crlSelector = NULL;
    PKIX_PL_X500Name *issuerName = NULL;
    pkix_CrlChecker *state = NULL; 
    PKIX_UInt32 crlStoreIndex = 0;
    PKIX_UInt32 numCrlStores = 0;
    PKIX_Boolean storeIsLocal = PKIX_FALSE;
    PKIX_List *crlList = NULL;
    PKIX_List *dpList = NULL;
    void *nbioContext = NULL;

    PKIX_ENTER(CERTCHAINCHECKER, "pkix_CrlChecker_CheckExternal");
    PKIX_NULLCHECK_FOUR(cert, issuer, checkerObject, pNBIOContext);
    
    nbioContext = *pNBIOContext;
    *pNBIOContext = NULL; /* prepare for Error exit */

    state = (pkix_CrlChecker*)checkerObject;
    
    PKIX_CHECK(
        PKIX_List_GetLength(state->certStores, &numCrlStores, plContext),
        PKIX_LISTGETLENGTHFAILED);

    /* Find a cert store that is capable of storing crls */
    for (;crlStoreIndex < numCrlStores;crlStoreIndex++) {
        PKIX_CHECK(
            PKIX_List_GetItem(state->certStores, crlStoreIndex,
                              (PKIX_PL_Object **)&certStore,
                              plContext),
            PKIX_LISTGETITEMFAILED);
        
        PKIX_CHECK(
            PKIX_CertStore_GetLocalFlag(certStore, &storeIsLocal,
                                        plContext),
            PKIX_CERTSTOREGETLOCALFLAGFAILED);
        if (storeIsLocal) {
            PKIX_CHECK(
                PKIX_CertStore_GetImportCrlCallback(certStore,
                                                    &storeImportCrlFn,
                                                    plContext),
                PKIX_CERTSTOREGETCHECKREVBYCRLFAILED);
            
            PKIX_CHECK(
                PKIX_CertStore_GetCrlCheckerFn(certStore,
                                               &storeCheckRevocationFn,
                                               plContext),
                PKIX_CERTSTOREGETCHECKREVBYCRLFAILED);
            
            if (storeImportCrlFn && storeCheckRevocationFn) {
                localStore = certStore;
                certStore = NULL;
                break;
            }
        }
        PKIX_DECREF(certStore);
    } /* while */

    /* Report unknown status if we can not check crl in one of the
     * local stores. */
    if (!localStore) {
        PKIX_ERROR_FATAL(PKIX_CRLCHECKERNOLOCALCERTSTOREFOUND);
    }
    PKIX_CHECK(
        PKIX_PL_Cert_VerifyKeyUsage(issuer, PKIX_CRL_SIGN, plContext),
        PKIX_CERTCHECKKEYUSAGEFAILED);
    PKIX_CHECK(
        PKIX_PL_Cert_GetCrlDp(cert, &dpList, plContext),
        PKIX_CERTGETCRLDPFAILED);
    if (!(methodFlags & PKIX_REV_M_REQUIRE_INFO_ON_MISSING_SOURCE) &&
        (!dpList || !dpList->length)) {
        goto cleanup;
    }
    PKIX_CHECK(
        PKIX_PL_Cert_GetIssuer(cert, &issuerName, plContext),
        PKIX_CERTGETISSUERFAILED);
    PKIX_CHECK(
        PKIX_CRLSelector_Create(issuer, dpList, date, &crlSelector, plContext),
        PKIX_CRLCHECKERSETSELECTORFAILED);
    /* Fetch crl and store in a local cert store */
    for (crlStoreIndex = 0;crlStoreIndex < numCrlStores;crlStoreIndex++) {
        PKIX_CertStore_CRLCallback getCrlsFn;

        PKIX_CHECK(
            PKIX_List_GetItem(state->certStores, crlStoreIndex,
                              (PKIX_PL_Object **)&certStore,
                              plContext),
            PKIX_LISTGETITEMFAILED);
        
        PKIX_CHECK(
            PKIX_CertStore_GetCRLCallback(certStore, &getCrlsFn,
                                          plContext),
            PKIX_CERTSTOREGETCRLCALLBACKFAILED);
        
        PKIX_CHECK(
            (*getCrlsFn)(certStore, crlSelector, &nbioContext,
                      &crlList, plContext),
            PKIX_GETCRLSFAILED);

        PKIX_CHECK(
            (*storeImportCrlFn)(localStore, issuerName, crlList, plContext),
            PKIX_CERTSTOREFAILTOIMPORTCRLLIST);
        
        PKIX_CHECK(
            (*storeCheckRevocationFn)(certStore, cert, issuer, date,
                                      /* done with crl downloading */
                                      PKIX_TRUE,
                                      pReasonCode, &revStatus, plContext),
            PKIX_CERTSTORECRLCHECKFAILED);
        if (revStatus != PKIX_RevStatus_NoInfo) {
            break;
        }
        PKIX_DECREF(crlList);
        PKIX_DECREF(certStore);
    } /* while */

cleanup:
    /* Update return flags */
    if (revStatus == PKIX_RevStatus_NoInfo && 
	((dpList && dpList->length > 0) ||
	 (methodFlags & PKIX_REV_M_REQUIRE_INFO_ON_MISSING_SOURCE)) &&
        methodFlags & PKIX_REV_M_FAIL_ON_MISSING_FRESH_INFO) {
        revStatus = PKIX_RevStatus_Revoked;
    }
    *pRevStatus = revStatus;

    PKIX_DECREF(dpList);
    PKIX_DECREF(crlList);
    PKIX_DECREF(certStore);
    PKIX_DECREF(issuerName);
    PKIX_DECREF(localStore);
    PKIX_DECREF(crlSelector);

    PKIX_RETURN(CERTCHAINCHECKER);
}