win32filestore.c

IBE是一种非对称密码技术

  unsigned char *algId = (unsigned char *)0;
  unsigned char *salt = (unsigned char *)0;
  unsigned char *oldHmac = (unsigned char *)0;
  unsigned char *newHmac = (unsigned char *)0;
  unsigned char *passwordInfo = (unsigned char *)0;
  unsigned char *password = (unsigned char *)0;
  unsigned char *oldPassword = (unsigned char *)0;
  VOLT_DECLARE_ERROR_TYPE (errorType)
  VOLT_DECLARE_FNCT_LINE (fnctLine)

  /* Initialize to "don't delete the password file".
   */
  deletePasswordFile = 0;

  do
  {
    /* If there is info, it must be a random object.
     */
    if (info != (Pointer)0)
    {
      random = (VtRandomObject)info;
      status = VT_ERROR_INVALID_ASSOCIATED_INFO;
      VOLT_SET_ERROR_TYPE (errorType, VT_ERROR_TYPE_PRIMARY)
      VOLT_SET_FNCT_LINE (fnctLine)
      if (VOLT_OBJECT_TYPE_NOT_EQUAL (info, VOLT_OBJECT_TYPE_RANDOM))
        break;
    }

    /* Make sure we have a password manager.
     */   
    PasswordManager = (VtPasswordManager)ctx->passwordCtx.PasswordFunction;
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_STORAGE_CTX;
    if (PasswordManager == (VtPasswordManager)0)
      break;

    /* Get the current password info and file handle.
     */
    VOLT_SET_ERROR_TYPE (errorType, 0)
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VoltGetSaltAndHmacFromFile (
      ctx, &iterationCount, &algId, &algIdLen, &salt, &saltLen,
      &oldHmac, &oldHmacLen, &fileName, &fileHandle);
    if (status != 0)
      break;

    /* Get a DigestImpl to be used to check the password. If the info
     * was in the file, algId contains the algID. If not, algID is NULL
     * and this function will use a default algorithm, allocate a new
     * buffer, and set that buffer with the algID.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VoltGetDigestImpl (libCtx, &algId, &algIdLen, &DigestImpl);
    if (status != 0)
      break;

    /* If there's no file, we're setting a new password.
     */
    if (fileHandle == (VoltFileHandle)0)
    {
      /* Get the password we'll be using.
       */
      VOLT_SET_FNCT_LINE (fnctLine)
      status = PasswordManager (
        (VtLibCtx)libCtx, ctx->passwordCtx.appData,
        VT_PASSWORD_MGR_PURPOSE_SET, &oldPassword, &oldPasswordLen,
        &password, &passwordLen);
      if (status != 0)
        break;

      /* Create the file to hold the password info.
       */
      VOLT_SET_FNCT_LINE (fnctLine)
      status = fileCtx->CtxCreateDirectories (fileCtx, fileName);
      if (status != 0)
        break;

      VOLT_SET_FNCT_LINE (fnctLine)
      status = fileCtx->CtxOpenFile (
        fileCtx, &fileHandle, fileName, VOLT_FILE_MODE_READ_OVERWRITE, 0);
      if (status != 0)
        break;      

      /* Build an empty salt buffer.
       */
      saltLen = VOLT_EXTRA_PASS_SALT_LEN;
      VOLT_SET_ERROR_TYPE (errorType, VT_ERROR_TYPE_PRIMARY)
      VOLT_SET_FNCT_LINE (fnctLine)
      status = VT_ERROR_MEMORY;
      salt = (unsigned char *)Z2Malloc (saltLen, 0);
      if (salt == (unsigned char *)0)
        break;

      /* Set the iteration count.
       */
      iterationCount = VOLT_EXTRA_PASS_ITERATION_COUNT;
      oldPassword = (unsigned char *)0;
      oldPasswordLen = 0;
    }
    else
    {
      /* If there is a file, there's an old password.
       */
      purpose = VT_PASSWORD_MGR_PURPOSE_CHANGE;
      do
      {
        /* Confirm that the old password is correct. First, get the
         * passwords.
         */
        VOLT_SET_ERROR_TYPE (errorType, 0)
        VOLT_SET_FNCT_LINE (fnctLine)
        status = PasswordManager (
        (VtLibCtx)libCtx, ctx->passwordCtx.appData, purpose,
          &oldPassword, &oldPasswordLen, &password, &passwordLen);
        if (status != 0)
          break;

        /* If the callback returned an empty old password we know it's
         * wrong. The password file is created only if there is a non
         * empty password set. So we want to retry in that case.
         */
        purpose = VT_PASSWORD_MGR_PURPOSE_CHANGE_RETRY;
        if ( (oldPassword == (unsigned char *)0) || (oldPasswordLen == 0) )
          continue;

        /* Use newHmac as a temp variable.
         */
        VOLT_SET_FNCT_LINE (fnctLine)
        status = ComputePasswordHmacAlloc (
          libCtx, random, VOLT_USE_SALT, DigestImpl,
          oldPassword, oldPasswordLen, salt, saltLen, &newHmac, &newHmacLen);
        if (status != 0)
          break;        

        /* Is the passwordHmac that we just computed the same as the HMAC
         * in the file? If so, we have the correct old password.
         */
        cmpResult = Z2Memcmp (newHmac, oldHmac, newHmacLen);

        Z2Free (newHmac);
        newHmac = (unsigned char *)0;

        if (cmpResult == 0)
          break;

      } while (1);      
      if (status != 0)
        break;
    }

    /* At this point we have both the correct old password and  the new
     * password. If the new password is empty, it means the caller
     * wants to clear any extra passwords set. So an empty password
     * should be treated as no password instead of an empty password.
     */
    if ( (password == (unsigned char *)0) || (passwordLen == 0) )
    {
      password = (unsigned char *)0;
      passwordLen = 0;
    }

    /* We now need to re-encrypt all the appropriate files serviced by
     * this storage provider with the new password.
     */
    VOLT_SET_ERROR_TYPE (errorType, 0)
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VoltReEncryptFiles (
      ctx, oldPassword, oldPasswordLen, password, passwordLen);
    if (status != 0)
      break;

    /* If the new password is empty we need to delete the password file
     * indicating that no password is set.
     */
    if (passwordLen == 0)
    {
      deletePasswordFile = 1;  
      break;
    }
    
    /* Compute the password values for the new password.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = ComputePasswordHmacAlloc (
      libCtx, random, VOLT_COMPUTE_SALT, DigestImpl, password, passwordLen,
      salt, saltLen, &newHmac, &newHmacLen);
    if (status != 0)
      break;
    
    /* Build the block of data that is the HMAC info stored in the file.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VoltBuildPasswordInfoAlloc (
      libCtx, algId, algIdLen, iterationCount, salt, saltLen,
      newHmac, newHmacLen, &passwordInfo, &passwordInfoLen);
    if (status != 0)
      break;

    /* Store the password HMAC info in the file. This is the password
     * file, so it does not take an extra password.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = mIcStoreData (
      ctx, passwordInfo, passwordInfoLen, (unsigned char *)0, 0,
      fileCtx, fileHandle);

  } while (0);

  if (fileHandle != (VoltFileHandle)0)
  {
    fileCtx->CtxCloseFile (fileCtx, &fileHandle);
    if (deletePasswordFile != 0)
      fileCtx->CtxDeleteFile (fileCtx, (VoltFileHandle *)0, fileName);
  }

  if ( (password != (unsigned char *)0) ||
       (oldPassword != (unsigned char *)0) )
  {
    PasswordManager (
      (VtLibCtx)libCtx, ctx->passwordCtx.appData,
      VT_PASSWORD_MGR_PURPOSE_RELEASE, &oldPassword, &oldPasswordLen,
      &password, &passwordLen);
  }

  if (fileName != (unsigned char *)0)
    Z2Free (fileName);
  if (algId != (unsigned char *)0)
    Z2Free (algId);
  if (salt != (unsigned char *)0)
    Z2Free (salt);
  if (oldHmac != (unsigned char *)0)
    Z2Free (oldHmac);
  if (newHmac != (unsigned char *)0)
    Z2Free (newHmac);
  if (passwordInfo != (unsigned char *)0)
    Z2Free (passwordInfo);

  if (status == 0)
    return status;

  VOLT_LOG_ERROR (
    (VtLibCtx)libCtx, status, errorType, fnctLine,
    "VoltWinSetExtraPassword", (char *)0)

  return (status);
}

int VoltWinClientSetExtraPassword (
   VtStorageCtx storageCtx,
   Pointer info
   )
{
  int status;
  unsigned int purpose, valueLen, passwordLen, oldPasswordLen, hmacLen, saltLen;
  VoltStorageCtx *ctx = (VoltStorageCtx *)storageCtx;
  VoltLibCtx *libCtx = (VoltLibCtx *)(ctx->voltObject.libraryCtx);
  VoltDefaultStorageCtx *localCtx =
    (VoltDefaultStorageCtx *)(ctx->localStorageCtx);  
  VtPasswordManager PasswordManager = (VtPasswordManager)0;
  VtRandomObject random = (VtRandomObject)0;
  unsigned char buffer[VOLT_EXTRA_PASS_SALT_LEN + VOLT_EXTRA_PASS_HMAC_LEN];
  unsigned char oldHmac[VOLT_EXTRA_PASS_HMAC_LEN];
  unsigned char *password = (unsigned char *)0;
  unsigned char *oldPassword = (unsigned char *)0;
  unsigned char *salt;
  unsigned char *passwordHmac;
  VOLT_DECLARE_ERROR_TYPE (errorType)
  VOLT_DECLARE_FNCT_LINE (fnctLine)

  salt = buffer;
  passwordHmac = salt + VOLT_EXTRA_PASS_SALT_LEN;
  saltLen = VOLT_EXTRA_PASS_SALT_LEN;
  hmacLen = VOLT_EXTRA_PASS_HMAC_LEN;

  do
  {
    /* If there is info, it must be a random object.
     */
    if (info != (Pointer)0)
    {
      random = (VtRandomObject)info;
      status = VT_ERROR_INVALID_ASSOCIATED_INFO;
      VOLT_SET_ERROR_TYPE (errorType, VT_ERROR_TYPE_PRIMARY)
      VOLT_SET_FNCT_LINE (fnctLine)
      if (VOLT_OBJECT_TYPE_NOT_EQUAL (info, VOLT_OBJECT_TYPE_RANDOM))
        break;
    }

    /* Make sure we have a password manager.
     */    
    PasswordManager = (VtPasswordManager)(ctx->passwordCtx.PasswordFunction);
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_STORAGE_CTX;
    if (PasswordManager == (VtPasswordManager)0)
      break;

    /* Get the current password info and file handle.
     */
    VOLT_SET_ERROR_TYPE (errorType, 0)
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VoltGetSaltAndHmacFromRegistry (ctx, buffer, &valueLen);
    if (status != 0)
      break;

    /* If valueLen is 0, there's no current password, we're setting a
     * new one.
     */
    if (valueLen == 0)
    {
      /* Get the password we'll be using.
       */
      VOLT_SET_FNCT_LINE (fnctLine)
      status = PasswordManager (
        (VtLibCtx)libCtx, ctx->passwordCtx.appData,
        VT_PASSWORD_MGR_PURPOSE_SET, &oldPassword, &oldPasswordLen,
        &password, &passwordLen);
      if (status != 0)
        break;

      /* Make sure oldPassword is still NULL. When we later on
       * re-encrypt, this variable has to be NULL so that we don't try
       * to use an old password with existing data. It was originally
       * NULL, but the password mgr might have reset it. The mgr should
       * not have reset it, but we'll make sure it's NULL because we
       * don't have control of the password mgr.
       */
      oldPassword = (unsigned char *)0;
      oldPasswordLen = 0;
    }
    else
    {
      /* If there is a old password info, there's an old password.
       */
      purpose = VT_PASSWORD_MGR_PURPOSE_CHANGE;
      do
      {
        /* Confirm that the old password is correct. First, get the
         * passwords.
         */
        VOLT_SET_FNCT_LINE (fnctLine)
        status = PasswordManager (
          (VtLibCtx)libCtx, ctx->passwordCtx.appData, purpose,
          &oldPassword, &oldPasswordLen, &password, &passwordLen);
        if (status != 0)
          break;

        /* If the callback returned an empty old password we know it's
         * wrong. The password file is created only if there is a non
         * empty password set. So we want to retry in that case.
         */
        purpose = VT_PASSWORD_MGR_PURPOSE_CHANGE_RETRY;
        if ( (oldPassword == (unsigned char *)0) || (oldPasswordLen == 0) )
          continue;

        VOLT_SET_FNCT_LINE (fnctLine)
        status = ComputePasswordValuesClient (
          libCtx, random, VOLT_USE_SALT, oldPassword, oldPasswordLen,
          salt, oldHmac, &hmacLen);
        if (status != 0)
          break;

        /* Is the passwordHmac that we just computed the same as the HMAC
         * in the file? If so, we have the correct old password.
         */
        if (Z2Memcmp (passwordHmac, oldHmac, hmacLen) == 0)
          break;

      } while (1);
      if (status != 0)
        break;
    }

    /* At this point we have both the correct old password and  the new
     * password. If the new password is empty, it means the caller
     * wants to clear any extra passwords set. So an empty password
     * should be treated as no password instead of an empty password.
     */
    if ( (password == (unsigned char *)0) || (passwordLen == 0) )
    {
      password = (unsigned char *)0;
      passwordLen = 0;
    }

    /* We now need to re-encrypt all the apprpriate files serviced by
     * this storage provider with the new password.
     */
    VOLT_SET_ERROR_TYPE (errorType, 0)
    VOLT_S