/* 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 envelopedData methods.

 */

#include "cmslocal.h"

#include "cert.h"

#include "keyhi.h"

#include "secasn1.h"

#include "secitem.h"

#include "secoid.h"

#include "pk11func.h"

#include "secerr.h"

#include "secpkcs5.h"

/*

 * NSS_CMSEnvelopedData_Create - create an enveloped data message

 */

NSSCMSEnvelopedData *

NSS_CMSEnvelopedData_Create(NSSCMSMessage *cmsg, SECOidTag algorithm, int keysize)

{

    void *mark;

    NSSCMSEnvelopedData *envd;

    PLArenaPool *poolp;

    SECStatus rv;

    poolp = cmsg->poolp;

    mark = PORT_ArenaMark(poolp);

    envd = (NSSCMSEnvelopedData *)PORT_ArenaZAlloc(poolp, sizeof(NSSCMSEnvelopedData));

    if (envd == NULL)

        goto loser;

    envd->cmsg = cmsg;

    /* version is set in NSS_CMSEnvelopedData_Encode_BeforeStart() */

    rv = NSS_CMSContentInfo_SetContentEncAlg(poolp, &(envd->contentInfo),

                                             algorithm, NULL, keysize);

    if (rv != SECSuccess)

        goto loser;

    PORT_ArenaUnmark(poolp, mark);

    return envd;

loser:

    PORT_ArenaRelease(poolp, mark);

    return NULL;

}

/*

 * NSS_CMSEnvelopedData_Destroy - destroy an enveloped data message

 */

void

NSS_CMSEnvelopedData_Destroy(NSSCMSEnvelopedData *edp)

{

    NSSCMSRecipientInfo **recipientinfos;

    NSSCMSRecipientInfo *ri;

    if (edp == NULL)

        return;

    recipientinfos = edp->recipientInfos;

    if (recipientinfos == NULL)

        return;

    while ((ri = *recipientinfos++) != NULL)

        NSS_CMSRecipientInfo_Destroy(ri);

    NSS_CMSContentInfo_Destroy(&(edp->contentInfo));

}

/*

 * NSS_CMSEnvelopedData_GetContentInfo - return pointer to this envelopedData's contentinfo

 */

NSSCMSContentInfo *

NSS_CMSEnvelopedData_GetContentInfo(NSSCMSEnvelopedData *envd)

{

    return &(envd->contentInfo);

}

/*

 * NSS_CMSEnvelopedData_AddRecipient - add a recipientinfo to the enveloped data msg

 *

 * rip must be created on the same pool as edp - this is not enforced, though.

 */

SECStatus

NSS_CMSEnvelopedData_AddRecipient(NSSCMSEnvelopedData *edp, NSSCMSRecipientInfo *rip)

{

    void *mark;

    SECStatus rv;

    /* XXX compare pools, if not same, copy rip into edp's pool */

    PR_ASSERT(edp != NULL);

    PR_ASSERT(rip != NULL);

    mark = PORT_ArenaMark(edp->cmsg->poolp);

    rv = NSS_CMSArray_Add(edp->cmsg->poolp, (void ***)&(edp->recipientInfos), (void *)rip);

    if (rv != SECSuccess) {

        PORT_ArenaRelease(edp->cmsg->poolp, mark);

        return SECFailure;

    }

    PORT_ArenaUnmark(edp->cmsg->poolp, mark);

    return SECSuccess;

}

/*

 * NSS_CMSEnvelopedData_Encode_BeforeStart - prepare this envelopedData for encoding

 *

 * at this point, we need

 * - recipientinfos set up with recipient's certificates

 * - a content encryption algorithm (if none, 3DES will be used)

 *

 * this function will generate a random content encryption key (aka bulk key),

 * initialize the recipientinfos with certificate identification and wrap the bulk key

 * using the proper algorithm for every certificiate.

 * it will finally set the bulk algorithm and key so that the encode step can find it.

 */

SECStatus

NSS_CMSEnvelopedData_Encode_BeforeStart(NSSCMSEnvelopedData *envd)

{

    int version;

    NSSCMSRecipientInfo **recipientinfos;

    NSSCMSContentInfo *cinfo;

    PK11SymKey *bulkkey = NULL;

    SECOidTag bulkalgtag;

    CK_MECHANISM_TYPE type;

    PK11SlotInfo *slot;

    SECStatus rv;

    SECItem *dummy;

    PLArenaPool *poolp;

    extern const SEC_ASN1Template NSSCMSRecipientInfoTemplate[];

    void *mark = NULL;

    int i;

    poolp = envd->cmsg->poolp;

    cinfo = &(envd->contentInfo);

    recipientinfos = envd->recipientInfos;

    if (recipientinfos == NULL) {

        PORT_SetError(SEC_ERROR_BAD_DATA);

#if 0

    PORT_SetErrorString("Cannot find recipientinfos to encode.");

#endif

        goto loser;

    }

    version = NSS_CMS_ENVELOPED_DATA_VERSION_REG;

    if (envd->originatorInfo != NULL || envd->unprotectedAttr != NULL) {

        version = NSS_CMS_ENVELOPED_DATA_VERSION_ADV;

    } else {

        for (i = 0; recipientinfos[i] != NULL; i++) {

            if (NSS_CMSRecipientInfo_GetVersion(recipientinfos[i]) != 0) {

                version = NSS_CMS_ENVELOPED_DATA_VERSION_ADV;

                break;

            }

        }

    }

    dummy = SEC_ASN1EncodeInteger(poolp, &(envd->version), version);

    if (dummy == NULL)

        goto loser;

    /* now we need to have a proper content encryption algorithm

     * on the SMIME level, we would figure one out by looking at SMIME capabilities

     * we cannot do that on our level, so if none is set already, we'll just go

     * with one of the mandatory algorithms (3DES) */

    if ((bulkalgtag = NSS_CMSContentInfo_GetContentEncAlgTag(cinfo)) == SEC_OID_UNKNOWN) {

        rv = NSS_CMSContentInfo_SetContentEncAlg(poolp, cinfo, SEC_OID_DES_EDE3_CBC, NULL, 168);

        if (rv != SECSuccess)

            goto loser;

        bulkalgtag = SEC_OID_DES_EDE3_CBC;

    }

    /* generate a random bulk key suitable for content encryption alg */

    type = PK11_AlgtagToMechanism(bulkalgtag);

    slot = PK11_GetBestSlot(type, envd->cmsg->pwfn_arg);

    if (slot == NULL)

        goto loser; /* error has been set by PK11_GetBestSlot */

    /* this is expensive... */

    bulkkey = PK11_KeyGen(slot, type, NULL,

                          NSS_CMSContentInfo_GetBulkKeySize(cinfo) / 8,

                          envd->cmsg->pwfn_arg);

    PK11_FreeSlot(slot);

    if (bulkkey == NULL)

        goto loser; /* error has been set by PK11_KeyGen */

    mark = PORT_ArenaMark(poolp);

    /* Encrypt the bulk key with the public key of each recipient.  */

    for (i = 0; recipientinfos[i] != NULL; i++) {

        rv = NSS_CMSRecipientInfo_WrapBulkKey(recipientinfos[i], bulkkey, bulkalgtag);

        if (rv != SECSuccess)

            goto loser; /* error has been set by NSS_CMSRecipientInfo_EncryptBulkKey */

                        /* could be: alg not supported etc. */

    }

    /* the recipientinfos are all finished. now sort them by DER for SET OF encoding */

    rv = NSS_CMSArray_SortByDER((void **)envd->recipientInfos,

                                NSSCMSRecipientInfoTemplate, NULL);

    if (rv != SECSuccess)

        goto loser; /* error has been set by NSS_CMSArray_SortByDER */

    /* store the bulk key in the contentInfo so that the encoder can find it */

    NSS_CMSContentInfo_SetBulkKey(cinfo, bulkkey);

    PORT_ArenaUnmark(poolp, mark);

    PK11_FreeSymKey(bulkkey);

    return SECSuccess;

loser:

    if (mark != NULL)

        PORT_ArenaRelease(poolp, mark);

    if (bulkkey)

        PK11_FreeSymKey(bulkkey);

    return SECFailure;

}

/*

 * NSS_CMSEnvelopedData_Encode_BeforeData - set up encryption

 *

 * it is essential that this is called before the contentEncAlg is encoded, because

 * setting up the encryption may generate IVs and thus change it!

 */

SECStatus

NSS_CMSEnvelopedData_Encode_BeforeData(NSSCMSEnvelopedData *envd)

{

    NSSCMSContentInfo *cinfo;

    PK11SymKey *bulkkey;

    SECAlgorithmID *algid;

    SECStatus rv;

    cinfo = &(envd->contentInfo);

    /* find bulkkey and algorithm - must have been set by NSS_CMSEnvelopedData_Encode_BeforeStart */

    bulkkey = NSS_CMSContentInfo_GetBulkKey(cinfo);

    if (bulkkey == NULL)

        return SECFailure;

    algid = NSS_CMSContentInfo_GetContentEncAlg(cinfo);

    if (algid == NULL)

        return SECFailure;

    rv = NSS_CMSContentInfo_Private_Init(cinfo);

    if (rv != SECSuccess) {

        return SECFailure;

    }

    /* this may modify algid (with IVs generated in a token).

     * it is essential that algid is a pointer to the contentEncAlg data, not a

     * pointer to a copy! */

    cinfo->privateInfo->ciphcx = NSS_CMSCipherContext_StartEncrypt(envd->cmsg->poolp, bulkkey, algid);

    PK11_FreeSymKey(bulkkey);

    if (cinfo->privateInfo->ciphcx == NULL)

        return SECFailure;

    return SECSuccess;

}

/*

 * NSS_CMSEnvelopedData_Encode_AfterData - finalize this envelopedData for encoding

 */

SECStatus

NSS_CMSEnvelopedData_Encode_AfterData(NSSCMSEnvelopedData *envd)

{

    if (envd->contentInfo.privateInfo && envd->contentInfo.privateInfo->ciphcx) {

        NSS_CMSCipherContext_Destroy(envd->contentInfo.privateInfo->ciphcx);

        envd->contentInfo.privateInfo->ciphcx = NULL;

    }

    /* nothing else to do after data */

    return SECSuccess;

}

/*

 * NSS_CMSEnvelopedData_Decode_BeforeData - find our recipientinfo,

 * derive bulk key & set up our contentinfo

 */

SECStatus

NSS_CMSEnvelopedData_Decode_BeforeData(NSSCMSEnvelopedData *envd)

{

    NSSCMSRecipientInfo *ri;

    PK11SymKey *bulkkey = NULL;

    SECOidTag bulkalgtag;

    SECAlgorithmID *bulkalg;

    SECStatus rv = SECFailure;

    NSSCMSContentInfo *cinfo;

    NSSCMSRecipient **recipient_list = NULL;

    NSSCMSRecipient *recipient;

    int rlIndex;

    if (NSS_CMSArray_Count((void **)envd->recipientInfos) == 0) {

        PORT_SetError(SEC_ERROR_BAD_DATA);

#if 0

    PORT_SetErrorString("No recipient data in envelope.");

#endif

        goto loser;

    }

    /* look if one of OUR cert's issuerSN is on the list of recipients, and if so,  */

    /* get the cert and private key for it right away */

    recipient_list = nss_cms_recipient_list_create(envd->recipientInfos);

    if (recipient_list == NULL)

        goto loser;

    /* what about multiple recipientInfos that match?

     * especially if, for some reason, we could not produce a bulk key with the first match?!

     * we could loop & feed partial recipient_list to PK11_FindCertAndKeyByRecipientList...

     * maybe later... */

    rlIndex = PK11_FindCertAndKeyByRecipientListNew(recipient_list, envd->cmsg->pwfn_arg);

    /* if that fails, then we're not an intended recipient and cannot decrypt */

    if (rlIndex < 0) {

        PORT_SetError(SEC_ERROR_NOT_A_RECIPIENT);

#if 0

    PORT_SetErrorString("Cannot decrypt data because proper key cannot be found.");

#endif

        goto loser;

    }

    recipient = recipient_list[rlIndex];

    if (!recipient->cert || !recipient->privkey) {

        /* XXX should set an error code ?!? */

        goto loser;

    }

    /* get a pointer to "our" recipientinfo */

    ri = envd->recipientInfos[recipient->riIndex];

    cinfo = &(envd->contentInfo);

    bulkalgtag = NSS_CMSContentInfo_GetContentEncAlgTag(cinfo);

    if (bulkalgtag == SEC_OID_UNKNOWN) {

        PORT_SetError(SEC_ERROR_INVALID_ALGORITHM);

    } else

        bulkkey =

            NSS_CMSRecipientInfo_UnwrapBulkKey(ri, recipient->subIndex,

                                               recipient->cert,

                                               recipient->privkey,

                                               bulkalgtag);

    if (bulkkey == NULL) {

        /* no success finding a bulk key */

        goto loser;

    }

    NSS_CMSContentInfo_SetBulkKey(cinfo, bulkkey);

    bulkalg = NSS_CMSContentInfo_GetContentEncAlg(cinfo);

    rv = NSS_CMSContentInfo_Private_Init(cinfo);

    if (rv != SECSuccess) {

        goto loser;

    }

    rv = SECFailure;

    cinfo->privateInfo->ciphcx = NSS_CMSCipherContext_StartDecrypt(bulkkey, bulkalg);

    if (cinfo->privateInfo->ciphcx == NULL)

        goto loser; /* error has been set by NSS_CMSCipherContext_StartDecrypt */

    rv = SECSuccess;

loser:

    if (bulkkey)

        PK11_FreeSymKey(bulkkey);

    if (recipient_list != NULL)

        nss_cms_recipient_list_destroy(recipient_list);

    return rv;

}

/*

 * NSS_CMSEnvelopedData_Decode_AfterData - finish decrypting this envelopedData's content

 */

SECStatus

NSS_CMSEnvelopedData_Decode_AfterData(NSSCMSEnvelopedData *envd)

{

    if (envd && envd->contentInfo.privateInfo && envd->contentInfo.privateInfo->ciphcx) {

        NSS_CMSCipherContext_Destroy(envd->contentInfo.privateInfo->ciphcx);

        envd->contentInfo.privateInfo->ciphcx = NULL;

    }

    return SECSuccess;

}

/*

 * NSS_CMSEnvelopedData_Decode_AfterEnd - finish decoding this envelopedData

 */

SECStatus

NSS_CMSEnvelopedData_Decode_AfterEnd(NSSCMSEnvelopedData *envd)

{

    /* apply final touches */

    return SECSuccess;

}