CC3200: SW updates via OTA dropbox failes

The problem was identified.

It is due to the "#" that appears now in the received Dropbox URL (in the response of the "/2/files/get_temporary_link" API) .

In order to trim the "#" you can use use the following code (replacing the CdnClient_ConnectByUrl() in cc3200-sdk\simplelink_extlib\ota\CdnClient.c):

_i32 CdnClient_ConnectByUrl(void *pvCdnClient, OtaFileMetadata_t *pResourceMetadata, _i32 secured_connection)
{
    CdnClient_t *pCdnClient = (CdnClient_t *)pvCdnClient;
    _u8 domain_name[64];
    _u8 req_uri[MAX_CDN_URL_LEN];
    _u8 *cdn_url = pResourceMetadata->cdn_url;
    _i32 status;

    /* fix for DropBox issue - i.e. getting trimming the '#' at the end of the URL */
    char* pBuf = (char*)cdn_url;
    if(pBuf = strstr(pBuf, "#"));
        *pBuf = 0;


    /* extract CDN server name and file name */
    status = http_extract_domain_by_url((_u8 *)cdn_url, domain_name, req_uri);
    if (status < 0)
    {
        Report("CdnClient_ConnectByUrl: ERROR, http_extract_domain_by_url, status=%ld\r\n", status);
        return OTA_STATUS_ERROR;
    }

    /* Skip connect server if same CDN server */
    if (strcmp((const char *)pCdnClient->cdn_server_name, (const char *)domain_name) != 0)
    {
        /* close previous CDN server socket */
        CdnClient_CloseServer(pCdnClient);
        strcpy((char *)pCdnClient->cdn_server_name, (const char *)domain_name);
        /* connect to the CDN server */
        pCdnClient->port_num = SOCKET_PORT_DEFAULT;
        do {
            pCdnClient->fileSockId = http_connect_server(pCdnClient->cdn_server_name, 0, pCdnClient->port_num, secured_connection, SOCKET_BLOCKING);
        } while(pCdnClient->fileSockId == SL_ESECT00MANYSSLOPENED); // Retry until previous connection is closed

	if (pCdnClient->fileSockId < 0)
        {
            Report("CdnClient_ConnectByUrl: ERROR on http_connect_server, status=%d\r\n", pCdnClient->fileSockId);
            CdnClient_CloseServer(pvCdnClient);
            if (pCdnClient->fileSockId == OTA_STATUS_ERROR_CONTINUOUS_ACCESS)
            {
                return OTA_STATUS_ERROR_CONTINUOUS_ACCESS;
            }
            return CDN_STATUS_ERROR_CONNECT_CDN;
        }
    }

    /* read file headers, skip all not relenant headers */
    status = _ReadFileHeaders(pCdnClient->fileSockId, pCdnClient->cdn_server_name, req_uri); 
    if (status < 0)
    {
        Report("CdnClient_ConnectByUrl: ERROR, _ReadFileHeaders, status=%ld\r\n", status);
        CdnClient_CloseServer(pvCdnClient);
        return CDN_STATUS_ERROR_READ_HDRS;
    }

    pCdnClient->totalBytesReceived = 0;
    pCdnClient->state = CDN_STATE_CDN_SERVER_CONNECTED;

    if (pResourceMetadata->flags & METADATA_FLAGS_NOT_SFLASH_STORAGE)
    {
        /* Host storage */
        pCdnClient->pFlcCb = pCdnClient->pFlcHostCb; /* switch (only for current file) to host storage  */
    }
    else
    {
        /* Sflash storage */
        pCdnClient->pFlcCb = pCdnClient->pFlcSflashCb; /* switch back to default SFLASH storage  */
    }

    /* save metadata */
    pCdnClient->pResourceMetadata = pResourceMetadata;

    return OTA_STATUS_OK;
}

This will require a rebuild of the OTA library and of the application.

If you have devices in the field, you will need to contact Dropbox and request that they will remove the "#" in the URL provided in the "/2/files/get_temporary_link" response.

Note due to the frequent changes in the Dropbox environment (of API, authentication methods and certificates) we recommend switching to another CDN server for OTA. Please refer to the library code as an example when porting to another server.

Note also that Dropbox is about to replace their certificate, and you should prepare for that in advance. See more details in: https://e2e.ti.com/support/wireless-connectivity/wi-fi-group/wifi/f/wi-fi-forum/977073/faq-simplelink-cc32xx-sdk-important-notice-for-customers-using-dropbox-for-ota-updates

Sorry. There is no server authentication using CC3200 so the certificate is not an issue (only on CC3220/3x).