/* 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/. */

/*

 * CMS digesting.

 */

#include "cmslocal.h"

#include "cert.h"

#include "keyhi.h"

#include "secitem.h"

#include "secoid.h"

#include "pk11func.h"

#include "prtime.h"

#include "secerr.h"

#include "smime.h"

/*  #define CMS_FIND_LEAK_MULTIPLE 1 */

#ifdef CMS_FIND_LEAK_MULTIPLE

static int stop_on_err = 1;

static int global_num_digests = 0;

#endif

struct digestPairStr {

    const SECHashObject *digobj;

    void *digcx;

};

typedef struct digestPairStr digestPair;

struct NSSCMSDigestContextStr {

    PRBool saw_contents;

    PLArenaPool *pool;

    int digcnt;

    digestPair *digPairs;

};

/*

 * NSS_CMSDigestContext_StartMultiple - start digest calculation using all the

 *  digest algorithms in "digestalgs" in parallel.

 */

NSSCMSDigestContext *

NSS_CMSDigestContext_StartMultiple(SECAlgorithmID **digestalgs)

{

    PLArenaPool *pool;

    NSSCMSDigestContext *cmsdigcx;

    int digcnt;

    int i;

#ifdef CMS_FIND_LEAK_MULTIPLE

    PORT_Assert(global_num_digests == 0 || !stop_on_err);

#endif

    digcnt = (digestalgs == NULL) ? 0 : NSS_CMSArray_Count((void **)digestalgs);

    /* It's OK if digcnt is zero.  We have to allow this for "certs only"

    ** messages.

    */

    pool = PORT_NewArena(2048);

    if (!pool)

        return NULL;

    cmsdigcx = PORT_ArenaNew(pool, NSSCMSDigestContext);

    if (cmsdigcx == NULL)

        goto loser;

    cmsdigcx->saw_contents = PR_FALSE;

    cmsdigcx->pool = pool;

    cmsdigcx->digcnt = digcnt;

    cmsdigcx->digPairs = PORT_ArenaZNewArray(pool, digestPair, digcnt);

    if (cmsdigcx->digPairs == NULL) {

        goto loser;

    }

    /*

     * Create a digest object context for each algorithm.

     */

    for (i = 0; i < digcnt; i++) {

        const SECHashObject *digobj;

        void *digcx;

        if (!NSS_SMIMEUtil_SigningAllowed(digestalgs[i])) {

            goto loser;

        }

        digobj = NSS_CMSUtil_GetHashObjByAlgID(digestalgs[i]);

        /*

         * Skip any algorithm we do not even recognize; obviously,

         * this could be a problem, but if it is critical then the

         * result will just be that the signature does not verify.

         * We do not necessarily want to error out here, because

         * the particular algorithm may not actually be important,

         * but we cannot know that until later.

         */

        if (digobj == NULL)

            continue;

        digcx = (*digobj->create)();

        if (digcx != NULL) {

            (*digobj->begin)(digcx);

            cmsdigcx->digPairs[i].digobj = digobj;

            cmsdigcx->digPairs[i].digcx = digcx;

#ifdef CMS_FIND_LEAK_MULTIPLE

            global_num_digests++;

#endif

        }

    }

    return cmsdigcx;

loser:

    /* free any earlier digest objects that may have bee allocated. */

    for (i = 0; i < digcnt; i++) {

        digestPair *pair = &cmsdigcx->digPairs[i];

        if (pair->digobj) {

            (*pair->digobj->destroy)(pair->digcx, PR_TRUE);

#ifdef CMS_FIND_LEAK_MULTIPLE

            --global_num_digests;

#endif

        }

    }

    if (pool) {

        PORT_FreeArena(pool, PR_FALSE);

    }

    return NULL;

}

/*

 * NSS_CMSDigestContext_StartSingle - same as

 * NSS_CMSDigestContext_StartMultiple, but only one algorithm.

 */

NSSCMSDigestContext *

NSS_CMSDigestContext_StartSingle(SECAlgorithmID *digestalg)

{

    SECAlgorithmID *digestalgs[] = { NULL, NULL }; /* fake array */

    digestalgs[0] = digestalg;

    return NSS_CMSDigestContext_StartMultiple(digestalgs);

}

/*

 * NSS_CMSDigestContext_Update - feed more data into the digest machine

 */

void

NSS_CMSDigestContext_Update(NSSCMSDigestContext *cmsdigcx,

                            const unsigned char *data, int len)

{

    int i;

    digestPair *pair = cmsdigcx->digPairs;

    cmsdigcx->saw_contents = PR_TRUE;

    for (i = 0; i < cmsdigcx->digcnt; i++, pair++) {

        if (pair->digcx) {

            (*pair->digobj->update)(pair->digcx, data, len);

        }

    }

}

/*

 * NSS_CMSDigestContext_Cancel - cancel digesting operation

 */

void

NSS_CMSDigestContext_Cancel(NSSCMSDigestContext *cmsdigcx)

{

    int i;

    digestPair *pair = cmsdigcx->digPairs;

    for (i = 0; i < cmsdigcx->digcnt; i++, pair++) {

        if (pair->digcx) {

            (*pair->digobj->destroy)(pair->digcx, PR_TRUE);

#ifdef CMS_FIND_LEAK_MULTIPLE

            --global_num_digests;

#endif

        }

    }

#ifdef CMS_FIND_LEAK_MULTIPLE

    PORT_Assert(global_num_digests == 0 || !stop_on_err);

#endif

    PORT_FreeArena(cmsdigcx->pool, PR_FALSE);

}

/*

 * NSS_CMSDigestContext_FinishMultiple - finish the digests and put them

 *  into an array of SECItems (allocated on poolp)

 */

SECStatus

NSS_CMSDigestContext_FinishMultiple(NSSCMSDigestContext *cmsdigcx,

                                    PLArenaPool *poolp,

                                    SECItem ***digestsp)

{

    SECItem **digests = NULL;

    digestPair *pair;

    void *mark;

    int i;

    SECStatus rv;

    /* no contents? do not finish digests */

    if (digestsp == NULL || !cmsdigcx->saw_contents) {

        rv = SECSuccess;

        goto cleanup;

    }

    mark = PORT_ArenaMark(poolp);

    /* allocate digest array & SECItems on arena */

    digests = PORT_ArenaNewArray(poolp, SECItem *, cmsdigcx->digcnt + 1);

    rv = ((digests == NULL) ? SECFailure : SECSuccess);

    pair = cmsdigcx->digPairs;

    for (i = 0; rv == SECSuccess && i < cmsdigcx->digcnt; i++, pair++) {

        SECItem digest;

        unsigned char hash[HASH_LENGTH_MAX];

        if (!pair->digcx) {

            digests[i] = NULL;

            continue;

        }

        digest.type = siBuffer;

        digest.data = hash;

        digest.len = pair->digobj->length;

        (*pair->digobj->end)(pair->digcx, hash, &digest.len, digest.len);

        digests[i] = SECITEM_ArenaDupItem(poolp, &digest);

        if (!digests[i]) {

            rv = SECFailure;

        }

    }

    digests[i] = NULL;

    if (rv == SECSuccess) {

        PORT_ArenaUnmark(poolp, mark);

    } else

        PORT_ArenaRelease(poolp, mark);

cleanup:

    NSS_CMSDigestContext_Cancel(cmsdigcx);

    /* Don't change the caller's digests pointer if we have no digests.

    **  NSS_CMSSignedData_Encode_AfterData depends on this behavior.

    */

    if (rv == SECSuccess && digestsp && digests) {

        *digestsp = digests;

    }

    return rv;

}

/*

 * NSS_CMSDigestContext_FinishSingle - same as

 * NSS_CMSDigestContext_FinishMultiple, but for one digest.

 */

SECStatus

NSS_CMSDigestContext_FinishSingle(NSSCMSDigestContext *cmsdigcx,

                                  PLArenaPool *poolp,

                                  SECItem *digest)

{

    SECStatus rv = SECFailure;

    SECItem **dp = NULL;

    PLArenaPool *arena = NULL;

    if ((arena = PORT_NewArena(1024)) == NULL)

        goto loser;

    /* get the digests into arena, then copy the first digest into poolp */

    rv = NSS_CMSDigestContext_FinishMultiple(cmsdigcx, arena, &dp);

    if (rv == SECSuccess && dp && dp[0]) {

        /* now copy it into poolp */

        rv = SECITEM_CopyItem(poolp, digest, dp[0]);

    }

loser:

    if (arena)

        PORT_FreeArena(arena, PR_FALSE);

    return rv;

}