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Angus Robertson

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Posts posted by Angus Robertson

  2. Posted

    You can check the original location header by keeping it in the onHeaderData event before the relocation actually happens. 

     

    I'm only auto URL encoding the redirection URL that the user can not change, not a URL passed to the component, that needs careful consideration.  Auto URL encoding is effectively what Firefox and Edge/Chrome do.

     

    < HTTP/1.1 302 Redirect
    < Content-Type: text/html; charset=UTF-8
    < Location: http://ec.gc.ca/Error 404.html

    < Content-Length: 153
    > GET /Error%20404.html HTTP/1.1

     

    Angus

     

  3. Posted

    I found the problem with HEAD and some redirections, it failed to start the redirected request until close was called, a bug that seems to have been there for many years.  Looked at my own link checker and I use GET not HEAD which is why I've never seen it.  Your 404 error page returns content even for 200 and HEAD.  It will be in SVN tonight.

     

    Angus

     

    • Like 1

  5. Posted

    I have investigated your URL and fixed it by correcting the bad relocation URL containing a space, at least for GET, but not yet for HEAD so another problem somewhere.  In my tests, the server closes the page as soon as a path with a space is found.  Testing with Firefox and Edge/Chrome suggests they correct the location path, only Edge displays it corrected. 

     

    Even after correcting the space the Error 404.html page is returned with a 200 response, despite the page saying HTTP Error 404 - Not Found in English and French, so certainly my link checker would assume the link was okay, I don't parse the page text, maybe you do?

     

    This also raises the issue of whether ICS should correct bad URLs, which browsers seem to do.  However, such correction is not trivial except for the simplest case of spaces, since we don't want to double encode / for instance. 

     

    Angus

     

     

     

  9. Posted

    I agree that UDP should send whole packets, but when they arrive two or more may be buffered before they are read in the DataAvailable event.  Also, they may not be sent as complete packets, for instance a record may be sent in one send/packet then a CRLF as the next send/packet, so if the application is waiting for that CRLF as a record separator, it needs two packets.  So best to treat UDP as a stream. 

     

    Angus

     

  10. Posted

    The most important issue about the DataAvailable event is not the size of your Receive/ReceiveFrom buffer, but that you should loop within the event continually reading all waiting data into a larger public receive buffer or stream until Receive/ReceiveFrom returns 0 or less.  If you don't do that, the event will be called again immediately you exit it to empty the internal receive buffers. 

     

    There is no guarantee about the length of data any call to Receive/ReceiveFrom will return even for UDP, it might take several events for a full packet to be assembled, rarely, but it can happen. 

     

    As I said before, all this is done for you in the OverbyteIcsIpStreamLog component

    .

    Angus

     

  11. Posted

    ICS V8.66 has been released at: http://wiki.overbyte.eu/wiki/index.php/ICS_Download

     

    ICS is a free internet component library for Delphi 7, 2006 to 2010, XE to XE8, 10 Seattle, 10.1 Berlin, 10.2 Tokyo, 10.3 Rio and 10.4 Sydney, and C++ Builder 2006 to XE3, 10.2 Tokyo, 10.3 Rio and 10.4 Sydney. ICS supports VCL and FMX, Win32, Win64 and MacOS 32-bit targets. The distribution zip includes the latest OpenSSL 1.1.1k win32, with other versions of OpenSSL being available from the download page.

     

    Changes in ICS V8.66 include:

     

    1 - Added a new TIcsInetAlive component to check for IPv4 and/or IPv6 internet connectivity, using Ping and/or HTTP, defaulting to  www.msftconnecttest.com run by Microsoft for Windows 10 alive checking. The online and offline check intervals may be set, and event fires when online state changes.  Sample OverbyteIcsHttpRestTst has a demo for new component.

     

    2 - OpenSSL 1.0.2 and 1.1.0 ceased security fix support over 12 months ago so ICS now only supports 1.1.1, with 3.0 support due in the next few months. This removes a lot of legacy code and functions, and several old ICS functions needed for backward compatibility.  Two components only used for 1.0.2 have been removed, TSslStaticLock and TSslDynamicLock which may give an error loading forms, until they are removed.  SslContext SslOptions is now ignored, use SslOptions2 instead which has more modern options.  Can not remove SslOptions because it's saved on too many DFMs. Most modern applications should not be using SslConext, but IcsHosts for servers for high level client components like TSslHttpRest.

     

    3 - Undertook a major clean-up of OpenSSL functions that may require end user application changes if low level OpenSSL functions have been used, hopefully very rarely. All OpenSSL functions have been renamed to their original names removing ICS f_ prefix for commonality with other Delphi applications.  Renamed literals BIO_CTRL_PENDING_, CRYPTO_NUM_LOCKS_, CRYPTO_LOCK_, OPENSSL_VERSION_ with underscore to avoid conflicts with functions of the  same case sensitive names. Removed unit OverbyteIcsLibeayEx not used for a while. Most OpenSSL type pointers to Dummy array are now
    simple Pointer type. Changed most OpenSSL var parameters to pointers for commonality.  New TSslWSocket method SslOK is TLS/SSL negotiated OK. LoadVerifyLocations no longer lets OpenSSL use default CA folder locations which is potentially a security risk.

     

    4 - Bring server SSL/TLS security levels up to latest Mozilla recommendations. In 2021 Mozilla now recommends TLSv1.3 as modern ciphers and TLSv1.2/1.3 as Intermediate supporting all browsers from last five years, so IcsHosts now use sslCiphersMozillaSrvTLS12 as Intermediate level, also Mozilla recommends no cipher server preference so changed that. Updated SslSrvSecurity levels: sslSrvSecInter, sslSrvSecInterFS and sslSrvSecHigh now all the same TLSv1.2 or 1.3, sslSrvSecTls12Less now TLSv1.2 only, sslSrvSecSsl3 not supported, only sslSrvSecBack supports TLSv1 and 1.1, sslSrvSecTls13Only  unchanged TLSv1.3 only.

     

    5 - Added support for YuOpenSSL which provides OpenSSL in a pre-built DCU statically linked into applications, rather than using external OpenSSL DLLs. This make application distribution more reliable since it can not fail by users deleting the DLLs or copying incompatible versions into the directory.   YuOpenSSL is a commercial product from https://www.yunqa.de/ and is supplied as separate compiled DCUs for Delphi 5 to 10.4. DEFINE YuOpenSSL in Include\OverbyteIcsDefs.inc determines whether the DCU is linked or the external DLLs.  Note only one version of OpenSSL can be linked with  YuOpenSSL, whereas different DLLs can be supported.  Apart from setting the define and adding a path to YuOpenSSL.dcu, no other application code changes are needed unless you check or report the DLL directory, when GSSLStaticLinked can be checked to see if OpenSSL is statically linked. Also worth noting that YuOpenSSL provides access to the all OpenSSL APIs, while ICS only accesses those DLL APIs needed for functionality we support.   

     

    6 - Added a better way of configuring Socks proxy and HTTP Tunnel proxy settings in TWSocket, similarly to that added for THttpCli in V8.62. The new ProxyURL property sets SOCKS or HTTP Tunnel proxy settings using a single URL, ie proto://[user:password@]host:port where proto is socks5 or http. Also added new methods SetSocks and SetHTTPTunnel to set proxy properties in a single call. Socks proxy and HTTP tunnelling again support host names, broken in V8.56. The sample OverbyteIcsSocksTst has been updated to demonstrate use of the new ProxyURL property and also now supports HTTP
    Tunnel proxy.

     

    7 - TIcsRestEmail has new OAAuthType property and event for OAuth2 browser URL perhaps via email for servers. TIcsRestEmail now sets OAuth2 errors, and clears old tokens. Increased default timeout for TIcsRestEmail AOuth2 login to 120 seconds since several web page warnings may be seen while attempting to login through the web page.

     

    8 - TIcsHttpMulti has a new ParseLevels property that follow links on a parsed web page to lower level pages, which are also parsed, looking for files to download with a specific file extension, ie .avi.  It ignores parent links without a file extension, and external links. This allows the component to download files indexed using HTTP from CCTV camera memory cards.

     

    9 - In TSslHttpRest ensure SSL is initialised for non-REST HTTP requests like GET, POST and PUT.

     

    10 - In TSslWSocketServer, added better error handling when IcsHosts SslCert is blank, so SslContext is still created for automatically created self signed certificates.

     

    11 - In TSslWSocketServer, TSslHttpAppSrv and TSslHttpSrv, added new onBeforeCtxInit event which if set is called once before each IcsHosts SslContext is initialised to allow the context parameters to be adjusted for special ciphers or protocols.

     

    12 - In THttpCli, AddrResolvedStr is now still available after the connection closes to report the IP address used for the connection.  When using an HTTPS proxy with the CONNECT command don't send host and port which some servers are unable to handle, probably broken with V8.64.

     

    13 - In TIcsMailQueue, added a new method CheckOAuthLogins that should be called before the queue starts when using OAuth2 email logins, which allows interactively checking with a browser of any OAuth2 login credentials, avoids asking for login first time email sent maybe days later. 14 - In TSslX509Certs, When starting the local web server for file challenges,  check the server IP address still exists or change to 0.0.0.0, may not work if multiple IPs exist.

     

    15 - Updated to OpenSSL 1.1.1k with two high security fixes, one introduced in the last version relating to a certificate chain validation that ICS does not use, the other relating to servers using TLSv1.2 and renegotiation, and that feature is removed in V8.66.

     

     

    • Like 7
    • Thanks 3

  13. Posted

    You can use the OverbyteIcsUdpLstn sample to see how to receive UDP data.  Your won't have megabytes of data waiting when that event is called, in fact you will never know how much UDP data is being sent since it only arrives one packet at a time.  So typically you use ReceiveFrom to receive a maximum of say 4K, and then add that to a large receive buffer. 

     

    Much easier to use the new OverbyteIcsIpStreamLog component which does all this for you, look at the OverbyteIcsIpStmLogTst sample.

     

    Angus

     

  16. Posted

    The proxy setters changes are now in SVN, with an updated OverbyteIcsSocksTst sample that now also tests HTTP Tunnelling, which we did not seem to do. Will be zipped overnight.

     

    I tested the HTTP Tunnelling changes against the ICS proxy server, which currently deliberately only tunnels HTTP, need to fix that, but have not tested socks since 7Proxy failed my 10 minutes to find out how to configure it limit, sure it works fine once you find some non-empty help files.

     

    Angus

     

    • Like 1

  18. Posted

    I've added  SetSocks and SetHTTPTunnel to TCustomSocksWSocket, with a new ProxyURL property.  Not in SVN yet.

     

    I can test HTTP Tunnelling through the ICS Proxy Server I have running on my public servers, but can not find any samples that use it.  We do have OverbyteIcsSocksTst, but I don't currently have a SOCKS server running. 

     

    Less sure about SetURL() which only sets the wsocket host and port, is that really worthwhile?

     

    Angus

     

  19. Posted

    You need a message handler in the thread execute loop, to handle all the events, these lines are from  TMailQuThread.Execute; in OverbyteIcsMailQueue.pas. 

     

     FIcsWndControl.ProcessMessages ;
    if FIcsWndControl.Terminated then break ;
    if NOT FActive then break ; // component
    if Terminated then break ;  // thread
    if (errorcounter > 10000) then break ;  // sanity check

     

    Angus

     

  24. Posted

    ICS is maintained using Delphi 2007, so is the best tested platform, provided I put the correct files in SVN. 

     

    VCLZlip is controlled by OverbyteVclZip.inc, and the version in my SVN has {.DEFINE Zipping}. 

     

    TIcsTwitter, etc were added six months ago to OverbyteIcsSslHttpRest.pas, so you probably have an old version somewhere.

     

    Angus

     

     

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