palemoon-dev/platform/security/manager/ssl/nsKeygenHandler.cpp

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * 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/. */

#include "base64.h"
#include "cryptohi.h"
#include "keyhi.h"
#include "mozilla/Assertions.h"
#include "nsIContent.h"
#include "nsIDOMHTMLSelectElement.h"
#include "nsIGenKeypairInfoDlg.h"
#include "nsIServiceManager.h"
#include "nsITokenDialogs.h"
#include "nsKeygenHandler.h"
#include "nsKeygenHandlerContent.h"
#include "nsKeygenThread.h"
#include "nsNSSComponent.h" // for PIPNSS string bundle calls.
#include "nsNSSHelper.h"
#include "nsReadableUtils.h"
#include "nsUnicharUtils.h"
#include "nsXULAppAPI.h"
#include "nspr.h"
#include "secasn1.h"
#include "secder.h"
#include "secdert.h"

DERTemplate SECAlgorithmIDTemplate[] = {
    { DER_SEQUENCE,
          0, nullptr, sizeof(SECAlgorithmID) },
    { DER_OBJECT_ID,
          offsetof(SECAlgorithmID,algorithm), },
    { DER_OPTIONAL | DER_ANY,
          offsetof(SECAlgorithmID,parameters), },
    { 0, }
};

DERTemplate CERTSubjectPublicKeyInfoTemplate[] = {
    { DER_SEQUENCE,
          0, nullptr, sizeof(CERTSubjectPublicKeyInfo) },
    { DER_INLINE,
          offsetof(CERTSubjectPublicKeyInfo,algorithm),
          SECAlgorithmIDTemplate, },
    { DER_BIT_STRING,
          offsetof(CERTSubjectPublicKeyInfo,subjectPublicKey), },
    { 0, }
};

DERTemplate CERTPublicKeyAndChallengeTemplate[] =
{
    { DER_SEQUENCE, 0, nullptr, sizeof(CERTPublicKeyAndChallenge) },
    { DER_ANY, offsetof(CERTPublicKeyAndChallenge,spki), },
    { DER_IA5_STRING, offsetof(CERTPublicKeyAndChallenge,challenge), },
    { 0, }
};

typedef struct curveNameTagPairStr {
    const char *curveName;
    SECOidTag curveOidTag;
} CurveNameTagPair;

static CurveNameTagPair nameTagPair[] =
{ 
  { "prime192v1", SEC_OID_ANSIX962_EC_PRIME192V1 },
  { "prime192v2", SEC_OID_ANSIX962_EC_PRIME192V2 },
  { "prime192v3", SEC_OID_ANSIX962_EC_PRIME192V3 },
  { "prime239v1", SEC_OID_ANSIX962_EC_PRIME239V1 },
  { "prime239v2", SEC_OID_ANSIX962_EC_PRIME239V2 },
  { "prime239v3", SEC_OID_ANSIX962_EC_PRIME239V3 },
  { "prime256v1", SEC_OID_ANSIX962_EC_PRIME256V1 },

  { "secp112r1", SEC_OID_SECG_EC_SECP112R1},
  { "secp112r2", SEC_OID_SECG_EC_SECP112R2},
  { "secp128r1", SEC_OID_SECG_EC_SECP128R1},
  { "secp128r2", SEC_OID_SECG_EC_SECP128R2},
  { "secp160k1", SEC_OID_SECG_EC_SECP160K1},
  { "secp160r1", SEC_OID_SECG_EC_SECP160R1},
  { "secp160r2", SEC_OID_SECG_EC_SECP160R2},
  { "secp192k1", SEC_OID_SECG_EC_SECP192K1},
  { "secp192r1", SEC_OID_ANSIX962_EC_PRIME192V1 },
  { "nistp192", SEC_OID_ANSIX962_EC_PRIME192V1 },
  { "secp224k1", SEC_OID_SECG_EC_SECP224K1},
  { "secp224r1", SEC_OID_SECG_EC_SECP224R1},
  { "nistp224", SEC_OID_SECG_EC_SECP224R1},
  { "secp256k1", SEC_OID_SECG_EC_SECP256K1},
  { "secp256r1", SEC_OID_ANSIX962_EC_PRIME256V1 },
  { "nistp256", SEC_OID_ANSIX962_EC_PRIME256V1 },
  { "secp384r1", SEC_OID_SECG_EC_SECP384R1},
  { "nistp384", SEC_OID_SECG_EC_SECP384R1},
  { "secp521r1", SEC_OID_SECG_EC_SECP521R1},
  { "nistp521", SEC_OID_SECG_EC_SECP521R1},

  { "c2pnb163v1", SEC_OID_ANSIX962_EC_C2PNB163V1 },
  { "c2pnb163v2", SEC_OID_ANSIX962_EC_C2PNB163V2 },
  { "c2pnb163v3", SEC_OID_ANSIX962_EC_C2PNB163V3 },
  { "c2pnb176v1", SEC_OID_ANSIX962_EC_C2PNB176V1 },
  { "c2tnb191v1", SEC_OID_ANSIX962_EC_C2TNB191V1 },
  { "c2tnb191v2", SEC_OID_ANSIX962_EC_C2TNB191V2 },
  { "c2tnb191v3", SEC_OID_ANSIX962_EC_C2TNB191V3 },
  { "c2onb191v4", SEC_OID_ANSIX962_EC_C2ONB191V4 },
  { "c2onb191v5", SEC_OID_ANSIX962_EC_C2ONB191V5 },
  { "c2pnb208w1", SEC_OID_ANSIX962_EC_C2PNB208W1 },
  { "c2tnb239v1", SEC_OID_ANSIX962_EC_C2TNB239V1 },
  { "c2tnb239v2", SEC_OID_ANSIX962_EC_C2TNB239V2 },
  { "c2tnb239v3", SEC_OID_ANSIX962_EC_C2TNB239V3 },
  { "c2onb239v4", SEC_OID_ANSIX962_EC_C2ONB239V4 },
  { "c2onb239v5", SEC_OID_ANSIX962_EC_C2ONB239V5 },
  { "c2pnb272w1", SEC_OID_ANSIX962_EC_C2PNB272W1 },
  { "c2pnb304w1", SEC_OID_ANSIX962_EC_C2PNB304W1 },
  { "c2tnb359v1", SEC_OID_ANSIX962_EC_C2TNB359V1 },
  { "c2pnb368w1", SEC_OID_ANSIX962_EC_C2PNB368W1 },
  { "c2tnb431r1", SEC_OID_ANSIX962_EC_C2TNB431R1 },

  { "sect113r1", SEC_OID_SECG_EC_SECT113R1},
  { "sect113r2", SEC_OID_SECG_EC_SECT113R2},
  { "sect131r1", SEC_OID_SECG_EC_SECT131R1},
  { "sect131r2", SEC_OID_SECG_EC_SECT131R2},
  { "sect163k1", SEC_OID_SECG_EC_SECT163K1},
  { "nistk163", SEC_OID_SECG_EC_SECT163K1},
  { "sect163r1", SEC_OID_SECG_EC_SECT163R1},
  { "sect163r2", SEC_OID_SECG_EC_SECT163R2},
  { "nistb163", SEC_OID_SECG_EC_SECT163R2},
  { "sect193r1", SEC_OID_SECG_EC_SECT193R1},
  { "sect193r2", SEC_OID_SECG_EC_SECT193R2},
  { "sect233k1", SEC_OID_SECG_EC_SECT233K1},
  { "nistk233", SEC_OID_SECG_EC_SECT233K1},
  { "sect233r1", SEC_OID_SECG_EC_SECT233R1},
  { "nistb233", SEC_OID_SECG_EC_SECT233R1},
  { "sect239k1", SEC_OID_SECG_EC_SECT239K1},
  { "sect283k1", SEC_OID_SECG_EC_SECT283K1},
  { "nistk283", SEC_OID_SECG_EC_SECT283K1},
  { "sect283r1", SEC_OID_SECG_EC_SECT283R1},
  { "nistb283", SEC_OID_SECG_EC_SECT283R1},
  { "sect409k1", SEC_OID_SECG_EC_SECT409K1},
  { "nistk409", SEC_OID_SECG_EC_SECT409K1},
  { "sect409r1", SEC_OID_SECG_EC_SECT409R1},
  { "nistb409", SEC_OID_SECG_EC_SECT409R1},
  { "sect571k1", SEC_OID_SECG_EC_SECT571K1},
  { "nistk571", SEC_OID_SECG_EC_SECT571K1},
  { "sect571r1", SEC_OID_SECG_EC_SECT571R1},
  { "nistb571", SEC_OID_SECG_EC_SECT571R1},

};

mozilla::UniqueSECItem
DecodeECParams(const char* curve)
{
    SECOidData *oidData = nullptr;
    SECOidTag curveOidTag = SEC_OID_UNKNOWN; /* default */
    int i, numCurves;

    if (curve && *curve) {
        numCurves = sizeof(nameTagPair)/sizeof(CurveNameTagPair);
        for (i = 0; ((i < numCurves) && (curveOidTag == SEC_OID_UNKNOWN)); 
             i++) {
            if (PL_strcmp(curve, nameTagPair[i].curveName) == 0)
                curveOidTag = nameTagPair[i].curveOidTag;
        }
    }

    /* Return nullptr if curve name is not recognized */
    if ((curveOidTag == SEC_OID_UNKNOWN) || 
        (oidData = SECOID_FindOIDByTag(curveOidTag)) == nullptr) {
        return nullptr;
    }

    mozilla::UniqueSECItem ecparams(SECITEM_AllocItem(nullptr, nullptr,
                                                      2 + oidData->oid.len));
    if (!ecparams) {
        return nullptr;
    }

    /* 
     * ecparams->data needs to contain the ASN encoding of an object ID (OID)
     * representing the named curve. The actual OID is in 
     * oidData->oid.data so we simply prepend 0x06 and OID length
     */
    ecparams->data[0] = SEC_ASN1_OBJECT_ID;
    ecparams->data[1] = oidData->oid.len;
    memcpy(ecparams->data + 2, oidData->oid.data, oidData->oid.len);

    return ecparams;
}

NS_IMPL_ISUPPORTS(nsKeygenFormProcessor, nsIFormProcessor)

nsKeygenFormProcessor::nsKeygenFormProcessor()
{ 
   m_ctx = new PipUIContext();
} 

nsKeygenFormProcessor::~nsKeygenFormProcessor()
{
  nsNSSShutDownPreventionLock locker;
  if (isAlreadyShutDown()) {
    return;
  }

  shutdown(ShutdownCalledFrom::Object);
}

nsresult
nsKeygenFormProcessor::Create(nsISupports* aOuter, const nsIID& aIID, void* *aResult)
{
  if (GeckoProcessType_Content == XRE_GetProcessType()) {
    nsCOMPtr<nsISupports> contentProcessor = new nsKeygenFormProcessorContent();
    return contentProcessor->QueryInterface(aIID, aResult);
  }

  nsresult rv;
  NS_ENSURE_NO_AGGREGATION(aOuter);
  nsKeygenFormProcessor* formProc = new nsKeygenFormProcessor();

  nsCOMPtr<nsISupports> stabilize = formProc;
  rv = formProc->Init();
  if (NS_SUCCEEDED(rv)) {
    rv = formProc->QueryInterface(aIID, aResult);
  }
  return rv;
}

nsresult
nsKeygenFormProcessor::Init()
{
  static NS_DEFINE_CID(kNSSComponentCID, NS_NSSCOMPONENT_CID);

  nsresult rv;

  nsCOMPtr<nsINSSComponent> nssComponent;
  nssComponent = do_GetService(kNSSComponentCID, &rv);
  if (NS_FAILED(rv))
    return rv;

  // Init possible key size choices.
  nssComponent->GetPIPNSSBundleString("HighGrade", mSECKeySizeChoiceList[0].name);
  mSECKeySizeChoiceList[0].size = 2048;

  nssComponent->GetPIPNSSBundleString("MediumGrade", mSECKeySizeChoiceList[1].name);
  mSECKeySizeChoiceList[1].size = 1024;

  return NS_OK;
}

nsresult
nsKeygenFormProcessor::GetSlot(uint32_t aMechanism, PK11SlotInfo** aSlot)
{
  nsNSSShutDownPreventionLock locker;
  if (isAlreadyShutDown()) {
    return NS_ERROR_NOT_AVAILABLE;
  }

  return GetSlotWithMechanism(aMechanism, m_ctx, aSlot, locker);
}

uint32_t MapGenMechToAlgoMech(uint32_t mechanism)
{
    uint32_t searchMech;

    /* We are interested in slots based on the ability to perform
       a given algorithm, not on their ability to generate keys usable
       by that algorithm. Therefore, map keygen-specific mechanism tags
       to tags for the corresponding crypto algorithm. */
    switch(mechanism)
    {
    case CKM_RSA_PKCS_KEY_PAIR_GEN:
        searchMech = CKM_RSA_PKCS;
        break;
    case CKM_RC4_KEY_GEN:
        searchMech = CKM_RC4;
        break;
    case CKM_DH_PKCS_KEY_PAIR_GEN:
        searchMech = CKM_DH_PKCS_DERIVE; /* ### mwelch  is this right? */
        break;
    case CKM_DES_KEY_GEN:
        /* What do we do about DES keygen? Right now, we're just using
           DES_KEY_GEN to look for tokens, because otherwise we'll have
           to search the token list three times. */
    case CKM_EC_KEY_PAIR_GEN:
        /* The default should also work for EC key pair generation. */
    default:
        searchMech = mechanism;
        break;
    }
    return searchMech;
}


nsresult
GetSlotWithMechanism(uint32_t aMechanism, nsIInterfaceRequestor* m_ctx,
                     PK11SlotInfo** aSlot, nsNSSShutDownPreventionLock& /*proofOfLock*/)
{
    PK11SlotList * slotList = nullptr;
    char16_t** tokenNameList = nullptr;
    nsCOMPtr<nsITokenDialogs> dialogs;
    char16_t *unicodeTokenChosen;
    PK11SlotListElement *slotElement, *tmpSlot;
    uint32_t numSlots = 0, i = 0;
    bool canceled;
    nsresult rv = NS_OK;

    *aSlot = nullptr;

    // Get the slot
    slotList = PK11_GetAllTokens(MapGenMechToAlgoMech(aMechanism), 
                                true, true, m_ctx);
    if (!slotList || !slotList->head) {
        rv = NS_ERROR_FAILURE;
        goto loser;
    }

    if (!slotList->head->next) {
        /* only one slot available, just return it */
        *aSlot = slotList->head->slot;
      } else {
        // Gerenate a list of slots and ask the user to choose //
        tmpSlot = slotList->head;
        while (tmpSlot) {
            numSlots++;
            tmpSlot = tmpSlot->next;
        }

        // Allocate the slot name buffer //
        tokenNameList = static_cast<char16_t**>(moz_xmalloc(sizeof(char16_t *) * numSlots));
        if (!tokenNameList) {
            rv = NS_ERROR_OUT_OF_MEMORY;
            goto loser;
        }

        i = 0;
        slotElement = PK11_GetFirstSafe(slotList);
        while (slotElement) {
            tokenNameList[i] = UTF8ToNewUnicode(nsDependentCString(PK11_GetTokenName(slotElement->slot)));
            slotElement = PK11_GetNextSafe(slotList, slotElement, false);
            if (tokenNameList[i])
                i++;
            else {
                // OOM. adjust numSlots so we don't free unallocated memory. 
                numSlots = i;
                PK11_FreeSlotListElement(slotList, slotElement);
                rv = NS_ERROR_OUT_OF_MEMORY;
                goto loser;
            }
        }

        // Throw up the token list dialog and get back the token.
        rv = getNSSDialogs(getter_AddRefs(dialogs), NS_GET_IID(nsITokenDialogs),
                           NS_TOKENDIALOGS_CONTRACTID);

        if (NS_FAILED(rv)) {
            goto loser;
        }

    if (!tokenNameList || !*tokenNameList) {
        rv = NS_ERROR_OUT_OF_MEMORY;
    } else {
        rv = dialogs->ChooseToken(m_ctx, (const char16_t**)tokenNameList,
                                  numSlots, &unicodeTokenChosen, &canceled);
    }
		if (NS_FAILED(rv)) goto loser;

		if (canceled) { rv = NS_ERROR_NOT_AVAILABLE; goto loser; }

        // Get the slot //
        slotElement = PK11_GetFirstSafe(slotList);
        nsAutoString tokenStr(unicodeTokenChosen);
        while (slotElement) {
            if (tokenStr.Equals(NS_ConvertUTF8toUTF16(PK11_GetTokenName(slotElement->slot)))) {
                *aSlot = slotElement->slot;
                PK11_FreeSlotListElement(slotList, slotElement);
                break;
            }
            slotElement = PK11_GetNextSafe(slotList, slotElement, false);
        }
        if(!(*aSlot)) {
            rv = NS_ERROR_FAILURE;
            goto loser;
        }
      }

      // Get a reference to the slot //
      PK11_ReferenceSlot(*aSlot);
loser:
      if (slotList) {
          PK11_FreeSlotList(slotList);
      }
      if (tokenNameList) {
          NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(numSlots, tokenNameList);
      }
      return rv;
}

nsresult
nsKeygenFormProcessor::GetPublicKey(const nsAString& aValue,
                                    const nsAString& aChallenge,
                                    const nsAFlatString& aKeyType,
                                    nsAString& aOutPublicKey,
                                    const nsAString& aKeyParams)
{
    nsNSSShutDownPreventionLock locker;
    if (isAlreadyShutDown()) {
      return NS_ERROR_NOT_AVAILABLE;
    }

    nsresult rv = NS_ERROR_FAILURE;
    UniquePORTString keystring;
    char *keyparamsString = nullptr;
    uint32_t keyGenMechanism;
    PK11SlotInfo *slot = nullptr;
    PK11RSAGenParams rsaParams;
    mozilla::UniqueSECItem ecParams;
    SECOidTag algTag;
    int keysize = 0;
    void *params = nullptr; // Non-owning.
    SECKEYPrivateKey *privateKey = nullptr;
    SECKEYPublicKey *publicKey = nullptr;
    CERTSubjectPublicKeyInfo *spkInfo = nullptr;
    SECStatus srv = SECFailure;
    SECItem spkiItem;
    SECItem pkacItem;
    SECItem signedItem;
    CERTPublicKeyAndChallenge pkac;
    pkac.challenge.data = nullptr;
    nsCOMPtr<nsIGeneratingKeypairInfoDialogs> dialogs;
    nsKeygenThread *KeygenRunnable = 0;
    nsCOMPtr<nsIKeygenThread> runnable;

    // permanent and sensitive flags for keygen
    PK11AttrFlags attrFlags = PK11_ATTR_TOKEN | PK11_ATTR_SENSITIVE | PK11_ATTR_PRIVATE;

    UniquePLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE));
    if (!arena) {
        goto loser;
    }

    // Get the key size //
    for (size_t i = 0; i < number_of_key_size_choices; ++i) {
        if (aValue.Equals(mSECKeySizeChoiceList[i].name)) {
            keysize = mSECKeySizeChoiceList[i].size;
            break;
        }
    }
    if (!keysize) {
        goto loser;
    }

    // Set the keygen mechanism
    if (aKeyType.IsEmpty() || aKeyType.LowerCaseEqualsLiteral("rsa")) {
        keyGenMechanism = CKM_RSA_PKCS_KEY_PAIR_GEN;
    } else if (aKeyType.LowerCaseEqualsLiteral("ec")) {
        keyparamsString = ToNewCString(aKeyParams);
        if (!keyparamsString) {
            rv = NS_ERROR_OUT_OF_MEMORY;
            goto loser;
        }

        keyGenMechanism = CKM_EC_KEY_PAIR_GEN;
        /* ecParams are initialized later */
    } else {
        goto loser;
    }

    // Get the slot
    rv = GetSlot(keyGenMechanism, &slot);
    if (NS_FAILED(rv)) {
        goto loser;
    }
    switch (keyGenMechanism) {
        case CKM_RSA_PKCS_KEY_PAIR_GEN:
            rsaParams.keySizeInBits = keysize;
            rsaParams.pe = DEFAULT_RSA_KEYGEN_PE;
            algTag = DEFAULT_RSA_KEYGEN_ALG;
            params = &rsaParams;
            break;
        case CKM_EC_KEY_PAIR_GEN:
            /* XXX We ought to rethink how the KEYGEN tag is 
             * displayed. The pulldown selections presented
             * to the user must depend on the keytype.
             * The displayed selection could be picked
             * from the keyparams attribute (this is currently called
             * the pqg attribute).
             * For now, we pick ecparams from the keyparams field
             * if it specifies a valid supported curve, or else 
             * we pick one of secp384r1, secp256r1 or secp192r1
             * respectively depending on the user's selection
             * (High, Medium, Low). 
             * (RSA uses RSA-2048, RSA-1024 and RSA-512 for historical
             * reasons, while ECC choices represent a stronger mapping)
             * NOTE: The user's selection
             * is silently ignored when a valid curve is presented
             * in keyparams.
             */
            ecParams = DecodeECParams(keyparamsString);
            if (!ecParams) {
                /* The keyparams attribute did not specify a valid
                 * curve name so use a curve based on the keysize.
                 * NOTE: Here keysize is used only as an indication of
                 * High/Medium/Low strength; elliptic curve
                 * cryptography uses smaller keys than RSA to provide
                 * equivalent security.
                 */
                switch (keysize) {
                case 2048:
                    ecParams = DecodeECParams("secp384r1");
                    break;
                case 1024:
                case 512:
                    ecParams = DecodeECParams("secp256r1");
                    break;
                } 
            }
            MOZ_ASSERT(ecParams);
            params = ecParams.get();
            /* XXX The signature algorithm ought to choose the hashing
             * algorithm based on key size once ECDSA variations based
             * on SHA256 SHA384 and SHA512 are standardized.
             */
            algTag = SEC_OID_ANSIX962_ECDSA_SIGNATURE_WITH_SHA1_DIGEST;
            break;
      default:
          goto loser;
      }

    /* Make sure token is initialized. */
    rv = setPassword(slot, m_ctx, locker);
    if (NS_FAILED(rv))
        goto loser;

    srv = PK11_Authenticate(slot, true, m_ctx);
    if (srv != SECSuccess) {
        goto loser;
    }

    rv = getNSSDialogs(getter_AddRefs(dialogs),
                       NS_GET_IID(nsIGeneratingKeypairInfoDialogs),
                       NS_GENERATINGKEYPAIRINFODIALOGS_CONTRACTID);

    if (NS_SUCCEEDED(rv)) {
        KeygenRunnable = new nsKeygenThread();
        NS_IF_ADDREF(KeygenRunnable);
    }

    if (NS_FAILED(rv) || !KeygenRunnable) {
        rv = NS_OK;
        privateKey = PK11_GenerateKeyPairWithFlags(slot, keyGenMechanism, params,
                                                   &publicKey, attrFlags, m_ctx);
    } else {
        KeygenRunnable->SetParams( slot, attrFlags, nullptr, 0,
                                   keyGenMechanism, params, m_ctx );

        runnable = do_QueryInterface(KeygenRunnable);
        if (runnable) {
            rv = dialogs->DisplayGeneratingKeypairInfo(m_ctx, runnable);
            // We call join on the thread so we can be sure that no
            // simultaneous access to the passed parameters will happen.
            KeygenRunnable->Join();

            if (NS_SUCCEEDED(rv)) {
                PK11SlotInfo *used_slot = nullptr;
                rv = KeygenRunnable->ConsumeResult(&used_slot, &privateKey, &publicKey);
                if (NS_SUCCEEDED(rv) && used_slot) {
                  PK11_FreeSlot(used_slot);
                }
            }
        }
    }
    
    if (NS_FAILED(rv) || !privateKey) {
        goto loser;
    }
    // just in case we'll need to authenticate to the db -jp //
    privateKey->wincx = m_ctx;

    /*
     * Create a subject public key info from the public key.
     */
    spkInfo = SECKEY_CreateSubjectPublicKeyInfo(publicKey);
    if ( !spkInfo ) {
        goto loser;
    }

    /*
     * Now DER encode the whole subjectPublicKeyInfo.
     */
    srv = DER_Encode(arena.get(), &spkiItem, CERTSubjectPublicKeyInfoTemplate,
                     spkInfo);
    if (srv != SECSuccess) {
        goto loser;
    }

    /*
     * set up the PublicKeyAndChallenge data structure, then DER encode it
     */
    pkac.spki = spkiItem;
    pkac.challenge.len = aChallenge.Length();
    pkac.challenge.data = (unsigned char *)ToNewCString(aChallenge);
    if (!pkac.challenge.data) {
        rv = NS_ERROR_OUT_OF_MEMORY;
        goto loser;
    }

    srv = DER_Encode(arena.get(), &pkacItem, CERTPublicKeyAndChallengeTemplate,
                     &pkac);
    if (srv != SECSuccess) {
        goto loser;
    }

    /*
     * now sign the DER encoded PublicKeyAndChallenge
     */
    srv = SEC_DerSignData(arena.get(), &signedItem, pkacItem.data, pkacItem.len,
                          privateKey, algTag);
    if (srv != SECSuccess) {
        goto loser;
    }

    /*
     * Convert the signed public key and challenge into base64/ascii.
     */
    keystring = UniquePORTString(
      BTOA_DataToAscii(signedItem.data, signedItem.len));
    if (!keystring) {
        rv = NS_ERROR_OUT_OF_MEMORY;
        goto loser;
    }

    CopyASCIItoUTF16(keystring.get(), aOutPublicKey);

    rv = NS_OK;
loser:
    if (srv != SECSuccess) {
        if ( privateKey ) {
            PK11_DestroyTokenObject(privateKey->pkcs11Slot,privateKey->pkcs11ID);
        }
        if ( publicKey ) {
            PK11_DestroyTokenObject(publicKey->pkcs11Slot,publicKey->pkcs11ID);
        }
    }
    if ( spkInfo ) {
        SECKEY_DestroySubjectPublicKeyInfo(spkInfo);
    }
    if ( publicKey ) {
        SECKEY_DestroyPublicKey(publicKey);
    }
    if ( privateKey ) {
        SECKEY_DestroyPrivateKey(privateKey);
    }
    if (slot) {
        PK11_FreeSlot(slot);
    }
    if (KeygenRunnable) {
        NS_RELEASE(KeygenRunnable);
    }
    if (keyparamsString) {
        free(keyparamsString);
    }
    if (pkac.challenge.data) {
        free(pkac.challenge.data);
    }
    return rv;
}

// static
void
nsKeygenFormProcessor::ExtractParams(nsIDOMHTMLElement* aElement,
                                     nsAString& challengeValue,
                                     nsAString& keyTypeValue,
                                     nsAString& keyParamsValue)
{
    aElement->GetAttribute(NS_LITERAL_STRING("keytype"), keyTypeValue);
    if (keyTypeValue.IsEmpty()) {
        // If this field is not present, we default to rsa.
        keyTypeValue.AssignLiteral("rsa");
    }

    aElement->GetAttribute(NS_LITERAL_STRING("pqg"),
                           keyParamsValue);
    /* XXX We can still support the pqg attribute in the keygen 
     * tag for backward compatibility while introducing a more 
     * general attribute named keyparams.
     */
    if (keyParamsValue.IsEmpty()) {
        aElement->GetAttribute(NS_LITERAL_STRING("keyparams"), 
                               keyParamsValue);
    }

    aElement->GetAttribute(NS_LITERAL_STRING("challenge"), challengeValue);
}

nsresult
nsKeygenFormProcessor::ProcessValue(nsIDOMHTMLElement* aElement,
                                    const nsAString& aName,
                                    nsAString& aValue)
{
    nsAutoString challengeValue;
    nsAutoString keyTypeValue;
    nsAutoString keyParamsValue;
    ExtractParams(aElement, challengeValue, keyTypeValue, keyParamsValue);

    return GetPublicKey(aValue, challengeValue, keyTypeValue, 
                        aValue, keyParamsValue);
}

nsresult
nsKeygenFormProcessor::ProcessValueIPC(const nsAString& aOldValue,
                                       const nsAString& aChallenge,
                                       const nsAString& aKeyType,
                                       const nsAString& aKeyParams,
                                       nsAString& newValue)
{
    return GetPublicKey(aOldValue, aChallenge, PromiseFlatString(aKeyType),
                        newValue, aKeyParams);
}

nsresult
nsKeygenFormProcessor::ProvideContent(const nsAString& aFormType,
                                      nsTArray<nsString>& aContent,
                                      nsAString& aAttribute)
{ 
  if (Compare(aFormType, NS_LITERAL_STRING("SELECT"),
              nsCaseInsensitiveStringComparator()) == 0) {

    for (size_t i = 0; i < number_of_key_size_choices; ++i) {
      aContent.AppendElement(mSECKeySizeChoiceList[i].name);
    }
    aAttribute.AssignLiteral("-mozilla-keygen");
  }
  return NS_OK;
}