[apple/security.git] / libsecurity_smime / lib / cmssigdata.c

/*
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Netscape security libraries.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are 
 * Copyright (C) 1994-2000 Netscape Communications Corporation.  All
 * Rights Reserved.
 * 
 * Contributor(s):
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL"), in which case the provisions of the GPL are applicable 
 * instead of those above.  If you wish to allow use of your 
 * version of this file only under the terms of the GPL and not to
 * allow others to use your version of this file under the MPL,
 * indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by
 * the GPL.  If you do not delete the provisions above, a recipient
 * may use your version of this file under either the MPL or the
 * GPL.
 */

/*
 * CMS signedData methods.
 */

#include <Security/SecCmsSignedData.h>

#include <Security/SecCmsContentInfo.h>
#include <Security/SecCmsDigestContext.h>
#include <Security/SecCmsSignerInfo.h>

#include "cmslocal.h"

#include "cert.h"
#include "SecAsn1Item.h"
#include "secoid.h"

#include <security_asn1/secasn1.h>
#include <security_asn1/secerr.h>
#include <security_asn1/secport.h>

#include <Security/SecCertificatePriv.h>

SecCmsSignedDataRef
SecCmsSignedDataCreate(SecCmsMessageRef cmsg)
{
    void *mark;
    SecCmsSignedDataRef sigd;
    PLArenaPool *poolp;

    poolp = cmsg->poolp;

    mark = PORT_ArenaMark(poolp);

    sigd = (SecCmsSignedDataRef)PORT_ArenaZAlloc (poolp, sizeof(SecCmsSignedData));
    if (sigd == NULL)
        goto loser;

    sigd->contentInfo.cmsg = cmsg;

    /* signerInfos, certs, certlists, crls are all empty */
    /* version is set in SecCmsSignedDataFinalize() */

    PORT_ArenaUnmark(poolp, mark);
    return sigd;

loser:
    PORT_ArenaRelease(poolp, mark);
    return NULL;
}

void
SecCmsSignedDataDestroy(SecCmsSignedDataRef sigd)
{
    SecCmsSignerInfoRef *signerinfos, si;

    if (sigd == NULL)
        return;

    if (sigd->certs != NULL)
        CFRelease(sigd->certs);

    signerinfos = sigd->signerInfos;
    if (signerinfos != NULL) {
        while ((si = *signerinfos++) != NULL)
            SecCmsSignerInfoDestroy(si);
    }

    /* everything's in a pool, so don't worry about the storage */
   SecCmsContentInfoDestroy(&(sigd->contentInfo));
}

/*
 * SecCmsSignedDataEncodeBeforeStart - do all the necessary things to a SignedData
 *     before start of encoding.
 *
 * In detail:
 *  - find out about the right value to put into sigd->version
 *  - come up with a list of digestAlgorithms (which should be the union of the algorithms
 *         in the signerinfos).
 *         If we happen to have a pre-set list of algorithms (and digest values!), we
 *         check if we have all the signerinfos' algorithms. If not, this is an error.
 */
OSStatus
SecCmsSignedDataEncodeBeforeStart(SecCmsSignedDataRef sigd)
{
    SecCmsSignerInfoRef signerinfo;
    SECOidTag digestalgtag;
    SecAsn1Item * dummy;
    int version;
    OSStatus rv;
    Boolean haveDigests = PR_FALSE;
    int n, i;
    PLArenaPool *poolp;

    poolp = sigd->contentInfo.cmsg->poolp;

    /* we assume that we have precomputed digests if there is a list of algorithms, and */
    /* a chunk of data for each of those algorithms */
    if (sigd->digestAlgorithms != NULL && sigd->digests != NULL) {
        for (i=0; sigd->digestAlgorithms[i] != NULL; i++) {
            if (sigd->digests[i] == NULL)
                break;
        }
        if (sigd->digestAlgorithms[i] == NULL)  /* reached the end of the array? */
            haveDigests = PR_TRUE;              /* yes: we must have all the digests */
    }
            
    version = SEC_CMS_SIGNED_DATA_VERSION_BASIC;

    /* RFC2630 5.1 "version is the syntax version number..." */
    if (SecCmsContentInfoGetContentTypeTag(&(sigd->contentInfo)) != SEC_OID_PKCS7_DATA)
        version = SEC_CMS_SIGNED_DATA_VERSION_EXT;

    /* prepare all the SignerInfos (there may be none) */
    for (i=0; i < SecCmsSignedDataSignerInfoCount(sigd); i++) {
        signerinfo = SecCmsSignedDataGetSignerInfo(sigd, i);

        /* RFC2630 5.1 "version is the syntax version number..." */
        if (SecCmsSignerInfoGetVersion(signerinfo) != SEC_CMS_SIGNER_INFO_VERSION_ISSUERSN)
            version = SEC_CMS_SIGNED_DATA_VERSION_EXT;
        
        /* collect digestAlgorithms from SignerInfos */
        /* (we need to know which algorithms we have when the content comes in) */
        /* do not overwrite any existing digestAlgorithms (and digest) */
        digestalgtag = SecCmsSignerInfoGetDigestAlgTag(signerinfo);
        n = SecCmsAlgArrayGetIndexByAlgTag(sigd->digestAlgorithms, digestalgtag);
        if (n < 0 && haveDigests) {
            /* oops, there is a digestalg we do not have a digest for */
            /* but we were supposed to have all the digests already... */
            goto loser;
        } else if (n < 0) {
            /* add the digestAlgorithm & a NULL digest */
            rv = SecCmsSignedDataAddDigest(poolp, sigd, digestalgtag, NULL);
            if (rv != SECSuccess)
                goto loser;
        } else {
            /* found it, nothing to do */
        }
    }

    dummy = SEC_ASN1EncodeInteger(poolp, &(sigd->version), (long)version);
    if (dummy == NULL)
        return SECFailure;

    /* this is a SET OF, so we need to sort them guys */
    rv = SecCmsArraySortByDER((void **)sigd->digestAlgorithms, 
                                SEC_ASN1_GET(SECOID_AlgorithmIDTemplate),
                                (void **)sigd->digests);
    if (rv != SECSuccess)
        return SECFailure;
    
    return SECSuccess;

loser:
    return SECFailure;
}

OSStatus
SecCmsSignedDataEncodeBeforeData(SecCmsSignedDataRef sigd)
{
    /* set up the digests */
    if (sigd->digestAlgorithms != NULL) {
        sigd->contentInfo.digcx = SecCmsDigestContextStartMultiple(sigd->digestAlgorithms);
        if (sigd->contentInfo.digcx == NULL)
            return SECFailure;
    }
    return SECSuccess;
}

/*
 * SecCmsSignedDataEncodeAfterData - do all the necessary things to a SignedData
 *     after all the encapsulated data was passed through the encoder.
 *
 * In detail:
 *  - create the signatures in all the SignerInfos
 *
 * Please note that nothing is done to the Certificates and CRLs in the message - this
 * is entirely the responsibility of our callers.
 */
OSStatus
SecCmsSignedDataEncodeAfterData(SecCmsSignedDataRef sigd)
{
    SecCmsSignerInfoRef *signerinfos, signerinfo;
    SecCmsContentInfoRef cinfo;
    SECOidTag digestalgtag;
    OSStatus ret = SECFailure;
    OSStatus rv;
    SecAsn1Item * contentType;
    CFIndex certcount;
    int i, ci, n, rci, si;
    PLArenaPool *poolp;
    CFArrayRef certlist;
    extern const SecAsn1Template SecCmsSignerInfoTemplate[];

    cinfo = &(sigd->contentInfo);
    poolp = cinfo->cmsg->poolp;

    /* did we have digest calculation going on? */
    if (cinfo->digcx) {
        SecAsn1Item **digests = NULL;
        SECAlgorithmID **digestalgs = NULL;
        rv = SecCmsDigestContextFinishMultiple(cinfo->digcx, &digestalgs, &digests);
        if (rv != SECSuccess)
            goto loser;         /* error has been set by SecCmsDigestContextFinishMultiple */
        if (digestalgs && digests) {
            rv = SecCmsSignedDataSetDigests(sigd, digestalgs, digests);
            if (rv != SECSuccess)
                goto loser;             /* error has been set by SecCmsSignedDataSetDigests */
        }
        SecCmsDigestContextDestroy(cinfo->digcx);
        cinfo->digcx = NULL;
    }

    signerinfos = sigd->signerInfos;
    certcount = 0;

    /* prepare all the SignerInfos (there may be none) */
    for (i=0; i < SecCmsSignedDataSignerInfoCount(sigd); i++) {
        signerinfo = SecCmsSignedDataGetSignerInfo(sigd, i);

        /* find correct digest for this signerinfo */
        digestalgtag = SecCmsSignerInfoGetDigestAlgTag(signerinfo);
        n = SecCmsAlgArrayGetIndexByAlgTag(sigd->digestAlgorithms, digestalgtag);
        if (n < 0 || sigd->digests == NULL || sigd->digests[n] == NULL) {
            /* oops - digest not found */
            PORT_SetError(SEC_ERROR_DIGEST_NOT_FOUND);
            goto loser;
        }

        /* XXX if our content is anything else but data, we need to force the
         * presence of signed attributes (RFC2630 5.3 "signedAttributes is a
         * collection...") */

        /* pass contentType here as we want a contentType attribute */
        if ((contentType = SecCmsContentInfoGetContentTypeOID(cinfo)) == NULL)
            goto loser;

        /* sign the thing */
        rv = SecCmsSignerInfoSign(signerinfo, sigd->digests[n], contentType);
        if (rv != SECSuccess)
            goto loser;

        /* while we're at it, count number of certs in certLists */
        certlist = SecCmsSignerInfoGetCertList(signerinfo);
        if (certlist)
            certcount += CFArrayGetCount(certlist);
    }

    /* this is a SET OF, so we need to sort them guys */
    rv = SecCmsArraySortByDER((void **)signerinfos, SecCmsSignerInfoTemplate, NULL);
    if (rv != SECSuccess)
        goto loser;

    /*
     * now prepare certs & crls
     */

    /* count the rest of the certs */
    if (sigd->certs != NULL)
        certcount += CFArrayGetCount(sigd->certs);

    if (certcount == 0) {
        sigd->rawCerts = NULL;
    } else {
        /*
         * Combine all of the certs and cert chains into rawcerts.
         * Note: certcount is an upper bound; we may not need that many slots
         * but we will allocate anyway to avoid having to do another pass.
         * (The temporary space saving is not worth it.)
         *
         * XXX ARGH - this NEEDS to be fixed. need to come up with a decent
         *  SetOfDERcertficates implementation
         */
        sigd->rawCerts = (SecAsn1Item * *)PORT_ArenaAlloc(poolp, (certcount + 1) * sizeof(SecAsn1Item *));
        if (sigd->rawCerts == NULL)
            return SECFailure;

        /*
         * XXX Want to check for duplicates and not add *any* cert that is
         * already in the set.  This will be more important when we start
         * dealing with larger sets of certs, dual-key certs (signing and
         * encryption), etc.  For the time being we can slide by...
         *
         * XXX ARGH - this NEEDS to be fixed. need to come up with a decent
         *  SetOfDERcertficates implementation
         */
        rci = 0;
        if (signerinfos != NULL) {
            for (si = 0; signerinfos[si] != NULL; si++) {
                signerinfo = signerinfos[si];
                for (ci = 0; ci < CFArrayGetCount(signerinfo->certList); ci++) {
                    sigd->rawCerts[rci] = PORT_ArenaZAlloc(poolp, sizeof(SecAsn1Item));
                    SecCertificateRef cert = (SecCertificateRef)CFArrayGetValueAtIndex(signerinfo->certList, ci);
                    SecAsn1Item cert_data = { SecCertificateGetLength(cert),
                        (uint8_t *)SecCertificateGetBytePtr(cert) };
                    *(sigd->rawCerts[rci++]) = cert_data;
                }
            }
        }

        if (sigd->certs != NULL) {
            for (ci = 0; ci < CFArrayGetCount(sigd->certs); ci++) {
                sigd->rawCerts[rci] = PORT_ArenaZAlloc(poolp, sizeof(SecAsn1Item));
                SecCertificateRef cert = (SecCertificateRef)CFArrayGetValueAtIndex(sigd->certs, ci);
                    SecAsn1Item cert_data = { SecCertificateGetLength(cert),
                        (uint8_t *)SecCertificateGetBytePtr(cert) };
                    *(sigd->rawCerts[rci++]) = cert_data;
            }
        }

        sigd->rawCerts[rci] = NULL;

        /* this is a SET OF, so we need to sort them guys - we have the DER already, though */
        SecCmsArraySort((void **)sigd->rawCerts, SecCmsUtilDERCompare, NULL, NULL);
    }

    ret = SECSuccess;

loser:
    return ret;
}

OSStatus
SecCmsSignedDataDecodeBeforeData(SecCmsSignedDataRef sigd)
{
    /* set up the digests, if we have digest algorithms, no digests yet, and content is attached */
    if (sigd->digestAlgorithms != NULL && sigd->digests == NULL /* && sigd->contentInfo.content.pointer != NULL*/) {
        /* if digests are already there, do nothing */
        sigd->contentInfo.digcx = SecCmsDigestContextStartMultiple(sigd->digestAlgorithms);
        if (sigd->contentInfo.digcx == NULL)
            return SECFailure;
    }
    return SECSuccess;
}

/*
 * SecCmsSignedDataDecodeAfterData - do all the necessary things to a SignedData
 *     after all the encapsulated data was passed through the decoder.
 */
OSStatus
SecCmsSignedDataDecodeAfterData(SecCmsSignedDataRef sigd)
{
    OSStatus rv = SECSuccess;

    /* did we have digest calculation going on? */
    if (sigd->contentInfo.digcx) {
        /* @@@ we should see if data was absent vs. zero length */
        if (sigd->contentInfo.content.data && sigd->contentInfo.content.data->Length) {
            SecAsn1Item * *digests = NULL;
            SECAlgorithmID **digestalgs = NULL;
            rv = SecCmsDigestContextFinishMultiple(sigd->contentInfo.digcx, &digestalgs, &digests);
            if (rv != SECSuccess)
                goto loser;             /* error has been set by SecCmsDigestContextFinishMultiple */
            rv = SecCmsSignedDataSetDigests(sigd, digestalgs, digests);
            if (rv != SECSuccess)
                goto loser;             /* error has been set by SecCmsSignedDataSetDigests */
        }
        SecCmsDigestContextDestroy(sigd->contentInfo.digcx);
        sigd->contentInfo.digcx = NULL;
    }

loser:
    return rv;
}

/*
 * SecCmsSignedDataDecodeAfterEnd - do all the necessary things to a SignedData
 *     after all decoding is finished.
 */
OSStatus
SecCmsSignedDataDecodeAfterEnd(SecCmsSignedDataRef sigd)
{
    SecCmsSignerInfoRef *signerinfos;
    int i;

    if (!sigd) {
        return SECFailure;
    }

    /* set cmsg for all the signerinfos */
    signerinfos = sigd->signerInfos;

    /* set signedData for all the signerinfos */
    if (signerinfos) {
        for (i = 0; signerinfos[i] != NULL; i++)
            signerinfos[i]->signedData = sigd;
    }

    return SECSuccess;
}

/* 
 * SecCmsSignedDataGetSignerInfos - retrieve the SignedData's signer list
 */
SecCmsSignerInfoRef *
SecCmsSignedDataGetSignerInfos(SecCmsSignedDataRef sigd)
{
    return sigd->signerInfos;
}

int
SecCmsSignedDataSignerInfoCount(SecCmsSignedDataRef sigd)
{
    return SecCmsArrayCount((void **)sigd->signerInfos);
}

SecCmsSignerInfoRef
SecCmsSignedDataGetSignerInfo(SecCmsSignedDataRef sigd, int i)
{
    return sigd->signerInfos[i];
}

/* 
 * SecCmsSignedDataGetDigestAlgs - retrieve the SignedData's digest algorithm list
 */
SECAlgorithmID **
SecCmsSignedDataGetDigestAlgs(SecCmsSignedDataRef sigd)
{
    return sigd->digestAlgorithms;
}

/*
 * SecCmsSignedDataGetContentInfo - return pointer to this signedData's contentinfo
 */
SecCmsContentInfoRef
SecCmsSignedDataGetContentInfo(SecCmsSignedDataRef sigd)
{
    return &(sigd->contentInfo);
}

/* 
 * SecCmsSignedDataGetCertificateList - retrieve the SignedData's certificate list
 */
SecAsn1Item * *
SecCmsSignedDataGetCertificateList(SecCmsSignedDataRef sigd)
{
    return sigd->rawCerts;
}

OSStatus
SecCmsSignedDataImportCerts(SecCmsSignedDataRef sigd, SecKeychainRef keychain,
                                SECCertUsage certusage, Boolean keepcerts)
{
    OSStatus rv = -1;
    return rv;
}

/*
 * XXX the digests need to be passed in BETWEEN the decoding and the verification in case
 *     of external signatures!
 */


/*
 * SecCmsSignedDataVerifySignerInfo - check the signatures.
 *
 * The digests were either calculated during decoding (and are stored in the
 * signedData itself) or set after decoding using SecCmsSignedDataSetDigests.
 *
 * The verification checks if the signing cert is valid and has a trusted chain
 * for the purpose specified by "policies".
 *
 * If trustRef is NULL the cert chain is verified and the VerificationStatus is set accordingly.
 * Otherwise a SecTrust object is returned for the caller to evaluate using SecTrustEvaluate().
 */
OSStatus
SecCmsSignedDataVerifySignerInfo(SecCmsSignedDataRef sigd, int i, 
                            SecKeychainRef keychainOrArray, CFTypeRef policies, SecTrustRef *trustRef)
{
    SecCmsSignerInfoRef signerinfo;
    SecCmsContentInfoRef cinfo;
    SECOidData *algiddata;
    SecAsn1Item *contentType, *digest;
    OSStatus status;

    cinfo = &(sigd->contentInfo);

    signerinfo = sigd->signerInfos[i];

    /* Signature or digest level verificationStatus errors should supercede
       certificate level errors, so check the digest and signature first.  */

    /* Find digest and contentType for signerinfo */
    algiddata = SecCmsSignerInfoGetDigestAlg(signerinfo);

    if (!sigd->digests) {
        SECAlgorithmID **digestalgs = SecCmsSignedDataGetDigestAlgs(sigd);
        SecCmsDigestContextRef digcx = SecCmsDigestContextStartMultiple(digestalgs);
        SecCmsSignedDataSetDigestContext(sigd, digcx);
        SecCmsDigestContextDestroy(digcx);
    }

    digest = SecCmsSignedDataGetDigestByAlgTag(sigd, algiddata->offset);

    contentType = SecCmsContentInfoGetContentTypeOID(cinfo);

    /* verify signature */
    status = SecCmsSignerInfoVerify(signerinfo, digest, contentType);
#if SECTRUST_VERBOSE_DEBUG
        syslog(LOG_ERR, "SecCmsSignedDataVerifySignerInfo: SecCmsSignerInfoVerify returned %d, will %sverify cert",
                (int)status, (status) ? "NOT " : "");
#endif
    if (status) {
        return status;
    }

    /* Now verify the certificate.  We only do this when the signature verification succeeds. Note that this
       behavior is different than the macOS code. */
    status = SecCmsSignerInfoVerifyCertificate(signerinfo, keychainOrArray, policies, trustRef);
#if SECTRUST_VERBOSE_DEBUG
        syslog(LOG_ERR, "SecCmsSignedDataVerifySignerInfo: SecCmsSignerInfoVerifyCertificate returned %d", (int)status);
#endif

    return status;
}

OSStatus
SecCmsSignedDataVerifyCertsOnly(SecCmsSignedDataRef sigd, 
                                  SecKeychainRef keychainOrArray, 
                                  CFTypeRef policies)
{
    OSStatus rv = SECSuccess;

    if (!sigd || !keychainOrArray || !sigd->rawCerts) {
        PORT_SetError(SEC_ERROR_INVALID_ARGS);
        return SECFailure;
    }

    SecAsn1Item **cert_datas = sigd->rawCerts;
    SecAsn1Item *cert_data;
    while ((cert_data = *cert_datas++) != NULL) {
        SecCertificateRef cert = SecCertificateCreateWithBytes(NULL, cert_data->Data, cert_data->Length);
        if (cert) {
            CFArrayRef certs = CFArrayCreate(kCFAllocatorDefault, (const void **)&cert, 1, NULL);
            rv |= CERT_VerifyCert(keychainOrArray, certs, policies, CFAbsoluteTimeGetCurrent(), NULL);
            CFRelease(certs);
            CFRelease(cert);
        }
        else
            rv |= SECFailure;
    }

    return rv;
}

/*
 * SecCmsSignedDataHasDigests - see if we have digests in place
 */
Boolean
SecCmsSignedDataHasDigests(SecCmsSignedDataRef sigd)
{
    return (sigd->digests != NULL);
}

OSStatus
SecCmsSignedDataAddCertList(SecCmsSignedDataRef sigd, CFArrayRef certlist)
{
    PORT_Assert(certlist != NULL);

    if (certlist == NULL)
        return SECFailure;

    if (!sigd->certs)
        sigd->certs = CFArrayCreateMutableCopy(NULL, 0, certlist);
    else
    {
        CFRange certlistRange = { 0, CFArrayGetCount(certlist) };
        CFArrayAppendArray(sigd->certs, certlist, certlistRange);
    }

    return SECSuccess;
}

/*
 * SecCmsSignedDataAddCertChain - add cert and its entire chain to the set of certs 
 */
OSStatus
SecCmsSignedDataAddCertChain(SecCmsSignedDataRef sigd, SecCertificateRef cert)
{
    CFArrayRef certlist;
    SECCertUsage usage;
    OSStatus rv;

    usage = certUsageEmailSigner;

    /* do not include root */
    certlist = CERT_CertChainFromCert(cert, usage, PR_FALSE);
    if (certlist == NULL)
        return SECFailure;

    rv = SecCmsSignedDataAddCertList(sigd, certlist);
    CFRelease(certlist);

    return rv;
}

OSStatus
SecCmsSignedDataAddCertificate(SecCmsSignedDataRef sigd, SecCertificateRef cert)
{
    PORT_Assert(cert != NULL);

    if (cert == NULL)
        return SECFailure;

    if (!sigd->certs)
        sigd->certs = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);

    CFArrayAppendValue(sigd->certs, cert);

    return SECSuccess;
}

Boolean
SecCmsSignedDataContainsCertsOrCrls(SecCmsSignedDataRef sigd)
{
    if (sigd->rawCerts != NULL && sigd->rawCerts[0] != NULL)
        return PR_TRUE;
    else if (sigd->rawCrls != NULL && sigd->rawCrls[0] != NULL)
        return PR_TRUE;
    else
        return PR_FALSE;
}

OSStatus
SecCmsSignedDataAddSignerInfo(SecCmsSignedDataRef sigd,
                              SecCmsSignerInfoRef signerinfo)
{
    void *mark;
    OSStatus rv;
    SECOidTag digestalgtag;
    PLArenaPool *poolp;

    poolp = sigd->contentInfo.cmsg->poolp;

    mark = PORT_ArenaMark(poolp);

    /* add signerinfo */
    rv = SecCmsArrayAdd(poolp, (void ***)&(sigd->signerInfos), (void *)signerinfo);
    if (rv != SECSuccess)
        goto loser;

    /*
     * add empty digest
     * Empty because we don't have it yet. Either it gets created during encoding
     * (if the data is present) or has to be set externally.
     * XXX maybe pass it in optionally?
     */
    digestalgtag = SecCmsSignerInfoGetDigestAlgTag(signerinfo);
    rv = SecCmsSignedDataSetDigestValue(sigd, digestalgtag, NULL);
    if (rv != SECSuccess)
        goto loser;

    /*
     * The last thing to get consistency would be adding the digest.
     */

    PORT_ArenaUnmark(poolp, mark);
    return SECSuccess;

loser:
    PORT_ArenaRelease (poolp, mark);
    return SECFailure;
}

SecAsn1Item *
SecCmsSignedDataGetDigestByAlgTag(SecCmsSignedDataRef sigd, SECOidTag algtag)
{
    int idx;

    if(sigd == NULL || sigd->digests == NULL) {
        return NULL;
    }
    idx = SecCmsAlgArrayGetIndexByAlgTag(sigd->digestAlgorithms, algtag);
    return (idx >= 0)?(sigd->digests)[idx]:NULL;
}

OSStatus
SecCmsSignedDataSetDigestContext(SecCmsSignedDataRef sigd,
                                 SecCmsDigestContextRef digestContext)
{
    SECAlgorithmID **digestalgs;
    SecAsn1Item * *digests;

    if (SecCmsDigestContextFinishMultiple(digestContext, &digestalgs, &digests) != SECSuccess)
        goto loser;
    if (SecCmsSignedDataSetDigests(sigd, digestalgs, digests) != SECSuccess)
        goto loser;

    return 0;
loser:
    return PORT_GetError();
}

/*
 * SecCmsSignedDataSetDigests - set a signedData's digests member
 *
 * "digestalgs" - array of digest algorithm IDs
 * "digests"    - array of digests corresponding to the digest algorithms
 */
OSStatus
SecCmsSignedDataSetDigests(SecCmsSignedDataRef sigd,
                                SECAlgorithmID **digestalgs,
                                SecAsn1Item * *digests)
{
    int cnt, i, idx;

    /* Check input structure and items in structure */
    if (sigd == NULL || sigd->digestAlgorithms == NULL || sigd->contentInfo.cmsg == NULL ||
        sigd->contentInfo.cmsg->poolp == NULL) {
        PORT_SetError(SEC_ERROR_INVALID_ARGS);
        return SECFailure;
    }

    /* Since we'll generate a empty digest for content-less messages
       whether or not they're detached, we have to avoid overwriting
       externally set digest for detached content => return early */
    if (sigd->digests && sigd->digests[0])
        return 0;

    /* we assume that the digests array is just not there yet */
/*
    PORT_Assert(sigd->digests == NULL);
    if (sigd->digests != NULL) {
        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
        return SECFailure;
    }
*/
    /* now allocate one (same size as digestAlgorithms) */
    if (sigd->digests == NULL) {
        cnt = SecCmsArrayCount((void **)sigd->digestAlgorithms);
        sigd->digests = PORT_ArenaZAlloc(sigd->contentInfo.cmsg->poolp, (cnt + 1) * sizeof(SecAsn1Item *));
        if (sigd->digests == NULL) {
            PORT_SetError(SEC_ERROR_NO_MEMORY);
            return SECFailure;
        }
    }
    
    for (i = 0; sigd->digestAlgorithms[i] != NULL; i++) {
        /* try to find the sigd's i'th digest algorithm in the array we passed in */
        idx = SecCmsAlgArrayGetIndexByAlgID(digestalgs, sigd->digestAlgorithms[i]);
        if (idx < 0) {
            PORT_SetError(SEC_ERROR_DIGEST_NOT_FOUND);
            return SECFailure;
        }

        /* found it - now set it */
        if ((sigd->digests[i] = SECITEM_AllocItem(sigd->contentInfo.cmsg->poolp, NULL, 0)) == NULL ||
            SECITEM_CopyItem(sigd->contentInfo.cmsg->poolp, sigd->digests[i], digests[idx]) != SECSuccess)
        {
            PORT_SetError(SEC_ERROR_NO_MEMORY);
            return SECFailure;
        }
    }
    return SECSuccess;
}

OSStatus
SecCmsSignedDataSetDigestValue(SecCmsSignedDataRef sigd,
                                SECOidTag digestalgtag,
                                SecAsn1Item * digestdata)
{
    SecAsn1Item * digest = NULL;
    PLArenaPool *poolp;
    void *mark;
    int n, cnt;

    poolp = sigd->contentInfo.cmsg->poolp;

    mark = PORT_ArenaMark(poolp);

   
    if (digestdata) {
        digest = (SecAsn1Item *) PORT_ArenaZAlloc(poolp,sizeof(SecAsn1Item));

        /* copy digestdata item to arena (in case we have it and are not only making room) */
        if (SECITEM_CopyItem(poolp, digest, digestdata) != SECSuccess)
            goto loser;
    }

    /* now allocate one (same size as digestAlgorithms) */
    if (sigd->digests == NULL) {
        cnt = SecCmsArrayCount((void **)sigd->digestAlgorithms);
        sigd->digests = PORT_ArenaZAlloc(sigd->contentInfo.cmsg->poolp, (cnt + 1) * sizeof(SecAsn1Item *));
        if (sigd->digests == NULL) {
                PORT_SetError(SEC_ERROR_NO_MEMORY);
                return SECFailure;
        }
    }

    n = -1;
    if (sigd->digestAlgorithms != NULL)
        n = SecCmsAlgArrayGetIndexByAlgTag(sigd->digestAlgorithms, digestalgtag);

    /* if not found, add a digest */
    if (n < 0) {
        if (SecCmsSignedDataAddDigest(poolp, sigd, digestalgtag, digest) != SECSuccess)
            goto loser;
    } else {
        /* replace NULL pointer with digest item (and leak previous value) */
        sigd->digests[n] = digest;
    }

    PORT_ArenaUnmark(poolp, mark);
    return SECSuccess;

loser:
    PORT_ArenaRelease(poolp, mark);
    return SECFailure;
}

OSStatus
SecCmsSignedDataAddDigest(PRArenaPool *poolp,
                                SecCmsSignedDataRef sigd,
                                SECOidTag digestalgtag,
                                SecAsn1Item * digest)
{
    SECAlgorithmID *digestalg;
    void *mark;

    mark = PORT_ArenaMark(poolp);

    digestalg = PORT_ArenaZAlloc(poolp, sizeof(SECAlgorithmID));
    if (digestalg == NULL)
        goto loser;

    if (SECOID_SetAlgorithmID (poolp, digestalg, digestalgtag, NULL) != SECSuccess) /* no params */
        goto loser;

    if (SecCmsArrayAdd(poolp, (void ***)&(sigd->digestAlgorithms), (void *)digestalg) != SECSuccess ||
        /* even if digest is NULL, add dummy to have same-size array */
        SecCmsArrayAdd(poolp, (void ***)&(sigd->digests), (void *)digest) != SECSuccess)
    {
        goto loser;
    }

    PORT_ArenaUnmark(poolp, mark);
    return SECSuccess;

loser:
    PORT_ArenaRelease(poolp, mark);
    return SECFailure;
}

SecAsn1Item *
SecCmsSignedDataGetDigestValue(SecCmsSignedDataRef sigd, SECOidTag digestalgtag)
{
    int n;

    if (sigd->digestAlgorithms == NULL)
        return NULL;

    n = SecCmsAlgArrayGetIndexByAlgTag(sigd->digestAlgorithms, digestalgtag);

    return (n < 0) ? NULL : sigd->digests[n];
}

/* =============================================================================
 * Misc. utility functions
 */

/*
 * SecCmsSignedDataCreateCertsOnly - create a certs-only SignedData.
 *
 * cert          - base certificates that will be included
 * include_chain - if true, include the complete cert chain for cert
 *
 * More certs and chains can be added via AddCertificate and AddCertChain.
 *
 * An error results in a return value of NULL and an error set.
 *
 * XXXX CRLs
 */
SecCmsSignedDataRef
SecCmsSignedDataCreateCertsOnly(SecCmsMessageRef cmsg, SecCertificateRef cert, Boolean include_chain)
{
    SecCmsSignedDataRef sigd;
    void *mark;
    PLArenaPool *poolp;
    OSStatus rv;

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

    sigd = SecCmsSignedDataCreate(cmsg);
    if (sigd == NULL)
        goto loser;

    /* no signerinfos, thus no digestAlgorithms */

    /* but certs */
    if (include_chain) {
        rv = SecCmsSignedDataAddCertChain(sigd, cert);
    } else {
        rv = SecCmsSignedDataAddCertificate(sigd, cert);
    }
    if (rv != SECSuccess)
        goto loser;

    /* RFC2630 5.2 sez:
     * In the degenerate case where there are no signers, the
     * EncapsulatedContentInfo value being "signed" is irrelevant.  In this
     * case, the content type within the EncapsulatedContentInfo value being
     * "signed" should be id-data (as defined in section 4), and the content
     * field of the EncapsulatedContentInfo value should be omitted.
     */
    rv = SecCmsContentInfoSetContentData(&(sigd->contentInfo), NULL, PR_TRUE);
    if (rv != SECSuccess)
        goto loser;

    PORT_ArenaUnmark(poolp, mark);
    return sigd;

loser:
    if (sigd)
        SecCmsSignedDataDestroy(sigd);
    PORT_ArenaRelease(poolp, mark);
    return NULL;
}

/* TODO:
 * SecCmsSignerInfoGetReceiptRequest()
 * SecCmsSignedDataHasReceiptRequest()
 * easy way to iterate over signers
 */