/* 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_ekuchecker.c
 *
 * User Defined ExtenedKeyUsage Function Definitions
 *
 */

#include "pkix_ekuchecker.h"

SECOidTag ekuOidStrings[] = {
    PKIX_KEY_USAGE_SERVER_AUTH_OID,
    PKIX_KEY_USAGE_CLIENT_AUTH_OID,
    PKIX_KEY_USAGE_CODE_SIGN_OID,
    PKIX_KEY_USAGE_EMAIL_PROTECT_OID,
    PKIX_KEY_USAGE_TIME_STAMP_OID,
    PKIX_KEY_USAGE_OCSP_RESPONDER_OID,
    PKIX_UNKNOWN_OID
};

typedef struct pkix_EkuCheckerStruct {
    PKIX_List *requiredExtKeyUsageOids;
    PKIX_PL_OID *ekuOID;
} pkix_EkuChecker;


/*
 * FUNCTION: pkix_EkuChecker_Destroy
 * (see comments for PKIX_DestructorCallback in pkix_pl_system.h)
 */
static PKIX_Error *
pkix_EkuChecker_Destroy(
        PKIX_PL_Object *object,
        void *plContext)
{
        pkix_EkuChecker *ekuCheckerState = NULL;

        PKIX_ENTER(EKUCHECKER, "pkix_EkuChecker_Destroy");
        PKIX_NULLCHECK_ONE(object);

        PKIX_CHECK(pkix_CheckType(object, PKIX_EKUCHECKER_TYPE, plContext),
                    PKIX_OBJECTNOTANEKUCHECKERSTATE);

        ekuCheckerState = (pkix_EkuChecker *)object;

        PKIX_DECREF(ekuCheckerState->ekuOID);
        PKIX_DECREF(ekuCheckerState->requiredExtKeyUsageOids);

cleanup:

        PKIX_RETURN(EKUCHECKER);
}

/*
 * FUNCTION: pkix_EkuChecker_RegisterSelf
 *
 * DESCRIPTION:
 *  Registers PKIX_PL_HTTPCERTSTORECONTEXT_TYPE and its related
 *  functions with systemClasses[]
 *
 * THREAD SAFETY:
 *  Not Thread Safe - for performance and complexity reasons
 *
 *  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_EkuChecker_RegisterSelf(void *plContext)
{
        extern pkix_ClassTable_Entry systemClasses[PKIX_NUMTYPES];
        pkix_ClassTable_Entry *entry = &systemClasses[PKIX_EKUCHECKER_TYPE];

        PKIX_ENTER(EKUCHECKER, "pkix_EkuChecker_RegisterSelf");

        entry->description = "EkuChecker";
        entry->typeObjectSize = sizeof(pkix_EkuChecker);
        entry->destructor = pkix_EkuChecker_Destroy;

        PKIX_RETURN(EKUCHECKER);
}

/*
 * FUNCTION: pkix_EkuChecker_Create
 * DESCRIPTION:
 *
 *  Creates a new Extend Key Usage CheckerState using "params" to retrieve
 *  application specified EKU for verification and stores it at "pState".
 *
 * PARAMETERS:
 *  "params"
 *      a PKIX_ProcessingParams links to PKIX_ComCertSelParams where a list of
 *      Extended Key Usage OIDs specified by application can be retrieved for
 *      verification.
 *  "pState"
 *      Address where state pointer will be stored. 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 UserDefinedModules Error if the function fails in a
 *      non-fatal way.
 *  Returns a Fatal Error if the function fails in an unrecoverable way.
 */
static PKIX_Error *
pkix_EkuChecker_Create(
        PKIX_ProcessingParams *params,
        pkix_EkuChecker **pState,
        void *plContext)
{
        pkix_EkuChecker *state = NULL;
        PKIX_CertSelector *certSelector = NULL;
        PKIX_ComCertSelParams *comCertSelParams = NULL;
        PKIX_List *requiredOids = NULL;

        PKIX_ENTER(EKUCHECKER, "pkix_EkuChecker_Create");
        PKIX_NULLCHECK_TWO(params, pState);

        PKIX_CHECK(PKIX_PL_Object_Alloc
                    (PKIX_EKUCHECKER_TYPE,
                    sizeof (pkix_EkuChecker),
                    (PKIX_PL_Object **)&state,
                    plContext),
                    PKIX_COULDNOTCREATEEKUCHECKERSTATEOBJECT);


        PKIX_CHECK(PKIX_ProcessingParams_GetTargetCertConstraints
                    (params, &certSelector, plContext),
                    PKIX_PROCESSINGPARAMSGETTARGETCERTCONSTRAINTSFAILED);

        if (certSelector != NULL) {

            /* Get initial EKU OIDs from ComCertSelParams, if set */
            PKIX_CHECK(PKIX_CertSelector_GetCommonCertSelectorParams
                       (certSelector, &comCertSelParams, plContext),
                       PKIX_CERTSELECTORGETCOMMONCERTSELECTORPARAMSFAILED);

            if (comCertSelParams != NULL) {
                PKIX_CHECK(PKIX_ComCertSelParams_GetExtendedKeyUsage
                           (comCertSelParams, &requiredOids, plContext),
                           PKIX_COMCERTSELPARAMSGETEXTENDEDKEYUSAGEFAILED);

            }
        }

        PKIX_CHECK(PKIX_PL_OID_Create
                    (PKIX_EXTENDEDKEYUSAGE_OID,
                    &state->ekuOID,
                    plContext),
                    PKIX_OIDCREATEFAILED);

        state->requiredExtKeyUsageOids = requiredOids;
        requiredOids = NULL;
        *pState = state;
        state = NULL;

cleanup:

        PKIX_DECREF(certSelector);
        PKIX_DECREF(comCertSelParams);
        PKIX_DECREF(requiredOids);
        PKIX_DECREF(state);

        PKIX_RETURN(EKUCHECKER);
}

/*
 * FUNCTION: pkix_EkuChecker_Check
 * DESCRIPTION:
 *
 *  This function determines the Extended Key Usage OIDs specified by the
 *  application is included in the Extended Key Usage OIDs of this "cert".
 *
 * 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.
 *  "unresolvedCriticalExtensions"
 *      A List OIDs. The OID for Extended Key Usage is removed.
 *  "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 UserDefinedModules Error if the function fails in
 *      a non-fatal way.
 *  Returns a Fatal Error if the function fails in an unrecoverable way.
 */
static PKIX_Error *
pkix_EkuChecker_Check(
        PKIX_CertChainChecker *checker,
        PKIX_PL_Cert *cert,
        PKIX_List *unresolvedCriticalExtensions,
        void **pNBIOContext,
        void *plContext)
{
        pkix_EkuChecker *state = NULL;
        PKIX_List *requiredExtKeyUsageList = NULL;
        PKIX_List *certExtKeyUsageList = NULL;
        PKIX_PL_OID *ekuOid = NULL;
        PKIX_Boolean isContained = PKIX_FALSE;
        PKIX_UInt32 numItems = 0;
        PKIX_UInt32 i;
        PKIX_Boolean checkResult = PKIX_TRUE;

        PKIX_ENTER(EKUCHECKER, "pkix_EkuChecker_Check");
        PKIX_NULLCHECK_THREE(checker, cert, pNBIOContext);

        *pNBIOContext = NULL; /* no non-blocking IO */

        PKIX_CHECK(
            PKIX_CertChainChecker_GetCertChainCheckerState
            (checker, (PKIX_PL_Object **)&state, plContext),
            PKIX_CERTCHAINCHECKERGETCERTCHAINCHECKERSTATEFAILED);

        requiredExtKeyUsageList = state->requiredExtKeyUsageOids;
        if (requiredExtKeyUsageList == NULL) {
            goto cleanup;
        }

        PKIX_CHECK(
            PKIX_List_GetLength(requiredExtKeyUsageList, &numItems,
                                plContext),
            PKIX_LISTGETLENGTHFAILED);
        if (numItems == 0) {
            goto cleanup;
        }

        PKIX_CHECK(
            PKIX_PL_Cert_GetExtendedKeyUsage(cert, &certExtKeyUsageList,
                                             plContext),
            PKIX_CERTGETEXTENDEDKEYUSAGEFAILED);

        if (certExtKeyUsageList == NULL) {
            goto cleanup;
        }
        
        for (i = 0; i < numItems; i++) {
            
            PKIX_CHECK(
                PKIX_List_GetItem(requiredExtKeyUsageList, i,
                                  (PKIX_PL_Object **)&ekuOid, plContext),
                PKIX_LISTGETITEMFAILED);

            PKIX_CHECK(
                pkix_List_Contains(certExtKeyUsageList,
                                   (PKIX_PL_Object *)ekuOid,
                                   &isContained,
                                   plContext),
                PKIX_LISTCONTAINSFAILED);
            
            PKIX_DECREF(ekuOid);
            if (isContained != PKIX_TRUE) {
                checkResult = PKIX_FALSE;
                goto cleanup;
            }
        }

cleanup:
        if (!pkixErrorResult && checkResult == PKIX_FALSE) {
            pkixErrorReceived = PKIX_TRUE;
            pkixErrorCode = PKIX_EXTENDEDKEYUSAGECHECKINGFAILED;
        }
        
        PKIX_DECREF(ekuOid);
        PKIX_DECREF(certExtKeyUsageList);
        PKIX_DECREF(state);

        PKIX_RETURN(EKUCHECKER);
}

/*
 * FUNCTION: pkix_EkuChecker_Initialize
 * (see comments in pkix_sample_modules.h)
 */
PKIX_Error *
PKIX_EkuChecker_Create(
        PKIX_ProcessingParams *params,
        PKIX_CertChainChecker **pEkuChecker,
        void *plContext)
{
        pkix_EkuChecker *state = NULL;
        PKIX_List *critExtOIDsList = NULL;

        PKIX_ENTER(EKUCHECKER, "PKIX_EkuChecker_Initialize");
        PKIX_NULLCHECK_ONE(params);

        /*
         * This function and functions in this file provide an example of how
         * an application defined checker can be hooked into libpkix.
         */

        PKIX_CHECK(pkix_EkuChecker_Create
                    (params, &state, plContext),
                    PKIX_EKUCHECKERSTATECREATEFAILED);

        PKIX_CHECK(PKIX_List_Create(&critExtOIDsList, plContext),
                    PKIX_LISTCREATEFAILED);

        PKIX_CHECK(PKIX_List_AppendItem
                    (critExtOIDsList,
                    (PKIX_PL_Object *)state->ekuOID,
                    plContext),
                    PKIX_LISTAPPENDITEMFAILED);

        PKIX_CHECK(PKIX_CertChainChecker_Create
                (pkix_EkuChecker_Check,
                PKIX_TRUE,                 /* forwardCheckingSupported */
                PKIX_FALSE,                /* forwardDirectionExpected */
                critExtOIDsList,
                (PKIX_PL_Object *) state,
                pEkuChecker,
                plContext),
                PKIX_CERTCHAINCHECKERCREATEFAILED);
cleanup:

        PKIX_DECREF(critExtOIDsList);
        PKIX_DECREF(state);

        PKIX_RETURN(EKUCHECKER);
}