Upload Delphi DLL Reference Documentation

Upload

Chilkat Upload is a freeware component that can be used to upload files over HTTP and HTTPS to a web server.

  • Supports both HTTP and HTTPS protocols.
  • Progress monitoring with percentage completion and "heartbeat" monitoring.
  • Abort capability.
  • Asynchronous uploads with real-time monitoring of percentage completion and number of bytes transferred.
  • Add arbitrary HTTP POST form parameters to your upload.
  • Upload multiple files in a single transaction.
  • Add arbitrary (custom) HTTP header fields to the HTTP upload.
  • Retrieve the HTTP response status, header, and body returned by the web server.

Create/Dispose

function CkUpload_Create: HCkUpload; stdcall;

Creates an instance of the HCkUpload object and returns a handle (i.e. a Pointer). The handle is passed in the 1st argument for the functions listed on this page.

procedure CkUpload_Dispose(handle: HCkUpload); stdcall;

Objects created by calling CkUpload_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function.

Properties

function CkUpload_getAbortCurrent(objHandle: HCkUpload): wordbool; stdcall;
procedure CkUpload_putAbortCurrent(objHandle: HCkUpload; newPropVal: wordbool); stdcall;

Introduced in version 9.5.0.58

When set to True, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to False when the next method is called. When the abort occurs, this property is reset to False. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

function CkUpload_getBandwidthThrottleUp(objHandle: HCkUpload): Integer; stdcall;
procedure CkUpload_putBandwidthThrottleUp(objHandle: HCkUpload; newPropVal: Integer); stdcall;

Introduced in version 9.5.0.49

If non-zero, limits (throttles) the upload bandwidth to approximately this maximum number of bytes per second. The default value of this property is 0.

Bandwidth Throttled Asynchronous HTTP Upload

function CkUpload_getChunkSize(objHandle: HCkUpload): Integer; stdcall;
procedure CkUpload_putChunkSize(objHandle: HCkUpload; newPropVal: Integer); stdcall;

The chunk size (in bytes) used by the underlying TCP/IP sockets for uploading files. The default value is 65535.

procedure CkUpload_getClientIpAddress(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putClientIpAddress(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__clientIpAddress(objHandle: HCkUpload): PWideChar; stdcall;

Introduced in version 9.5.0.49

The IP address to use for computers with multiple network interfaces or IP addresses. For computers with a single network interface (i.e. most computers), this property should not be set. For multihoming computers, the default IP address is automatically used if this property is not set.

The IP address is a string such as in dotted notation using numbers, not domain names, such as "165.164.55.124".

procedure CkUpload_getDebugLogFilePath(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putDebugLogFilePath(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__debugLogFilePath(objHandle: HCkUpload): PWideChar; stdcall;

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

function CkUpload_getExpect100Continue(objHandle: HCkUpload): wordbool; stdcall;
procedure CkUpload_putExpect100Continue(objHandle: HCkUpload; newPropVal: wordbool); stdcall;

When True, the request header will included an "Expect: 100-continue" header field. This indicates that the server should respond with an intermediate response of "100 Continue" or "417 Expectation Failed" response based on the information available in the request header. This helps avoid situations such as limits on upload sizes. It allows the server to reject the upload, and then the client can abort prior to uploading the data.

The default value of this property is True.

procedure CkUpload_getHostname(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putHostname(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__hostname(objHandle: HCkUpload): PWideChar; stdcall;

The hostname of the HTTP server that is the target of the upload. Do not include "http://" in the hostname. It can be a hostname, such as "www.chilkatsoft.com", or an IP address, such as "168.144.70.227".

function CkUpload_getIdleTimeoutMs(objHandle: HCkUpload): Integer; stdcall;
procedure CkUpload_putIdleTimeoutMs(objHandle: HCkUpload; newPropVal: Integer); stdcall;

A timeout in milliseconds. The default value is 30000. If the upload hangs (i.e. progress halts) for more than this time, the component will abort the upload. (It will timeout.)

procedure CkUpload_getLastErrorHtml(objHandle: HCkUpload; outPropVal: HCkString); stdcall;

function CkUpload__lastErrorHtml(objHandle: HCkUpload): PWideChar; stdcall;

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

procedure CkUpload_getLastErrorText(objHandle: HCkUpload; outPropVal: HCkString); stdcall;

function CkUpload__lastErrorText(objHandle: HCkUpload): PWideChar; stdcall;

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

procedure CkUpload_getLastErrorXml(objHandle: HCkUpload; outPropVal: HCkString); stdcall;

function CkUpload__lastErrorXml(objHandle: HCkUpload): PWideChar; stdcall;

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

function CkUpload_getLastMethodSuccess(objHandle: HCkUpload): wordbool; stdcall;
procedure CkUpload_putLastMethodSuccess(objHandle: HCkUpload; newPropVal: wordbool); stdcall;

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = True and failure = False.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

procedure CkUpload_getLogin(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putLogin(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__login(objHandle: HCkUpload): PWideChar; stdcall;

The HTTP login for sites requiring authentication. Chilkat Upload supports Basic HTTP authentication.

function CkUpload_getNumBytesSent(objHandle: HCkUpload): LongWord; stdcall;

After an upload has completed, this property contains the number of bytes sent. During asynchronous uploads, this property contains the current number of bytes sent while the upload is in progress.

procedure CkUpload_getPassword(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putPassword(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__password(objHandle: HCkUpload): PWideChar; stdcall;

The HTTP password for sites requiring authentication. Chilkat Upload supports Basic HTTP authentication.

procedure CkUpload_getPath(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putPath(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__path(objHandle: HCkUpload): PWideChar; stdcall;

The path part of the upload URL. Some examples:

If the upload target (i.e. consumer) URL is: http://www.freeaspupload.net/freeaspupload/testUpload.asp, then

Hostname = "www.freeaspupload.net" Path = "/freeaspupload/testUpload.asp"
If the upload target URL is http://www.chilkatsoft.com/cgi-bin/ConsumeUpload.exe, then
Hostname = "www.chilkatsoft.com" Path = "/cgi-bin/ConsumeUpload.exe"

function CkUpload_getPercentUploaded(objHandle: HCkUpload): LongWord; stdcall;

Contains the current percentage completion (0 to 100) while an asynchronous upload is in progress.

function CkUpload_getPort(objHandle: HCkUpload): Integer; stdcall;
procedure CkUpload_putPort(objHandle: HCkUpload; newPropVal: Integer); stdcall;

The port number of the upload target (i.e. consumer) URL. The default value is 80. If SSL is used, this should be set to 443 (typically).

function CkUpload_getPreferIpv6(objHandle: HCkUpload): wordbool; stdcall;
procedure CkUpload_putPreferIpv6(objHandle: HCkUpload; newPropVal: wordbool); stdcall;

If True, then use IPv6 over IPv4 when both are supported for a particular domain. The default value of this property is False, which will choose IPv4 over IPv6.

procedure CkUpload_getProxyDomain(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putProxyDomain(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__proxyDomain(objHandle: HCkUpload): PWideChar; stdcall;

The domain name of a proxy host if an HTTP proxy is used. Do not include the "http://". The domain name may be a hostname, such as "www.chilkatsoft.com", or an IP address, such as "168.144.70.227".

HTTP Upload using a Proxy Server Example

procedure CkUpload_getProxyLogin(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putProxyLogin(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__proxyLogin(objHandle: HCkUpload): PWideChar; stdcall;

If an HTTP proxy is used and it requires authentication, this property specifies the HTTP proxy login.

procedure CkUpload_getProxyPassword(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putProxyPassword(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__proxyPassword(objHandle: HCkUpload): PWideChar; stdcall;

If an HTTP proxy is used and it requires authentication, this property specifies the HTTP proxy password.

function CkUpload_getProxyPort(objHandle: HCkUpload): Integer; stdcall;
procedure CkUpload_putProxyPort(objHandle: HCkUpload; newPropVal: Integer); stdcall;

The port number of a proxy server if an HTTP proxy is used.

procedure CkUpload_getResponseBody(objHandle: HCkUpload; outPropVal: HCkByteData); stdcall;

An HTTP upload is nothing more than an HTTP POST that contains the content of the files being uploaded. Just as with any HTTP POST or GET, the server should send an HTTP response that consists of header and body.

This property contains the body part of the HTTP response.

procedure CkUpload_getResponseHeader(objHandle: HCkUpload; outPropVal: HCkString); stdcall;

function CkUpload__responseHeader(objHandle: HCkUpload): PWideChar; stdcall;

An HTTP upload is nothing more than an HTTP POST that contains the content of the files being uploaded. Just as with any HTTP POST or GET, the server should send an HTTP response that consists of header and body.

This property contains the header part of the HTTP response.

function CkUpload_getResponseStatus(objHandle: HCkUpload): Integer; stdcall;

The HTTP response status code of the HTTP response. A list of HTTP status codes can be found here: HTTP Response Status Codes.

function CkUpload_getSsl(objHandle: HCkUpload): wordbool; stdcall;
procedure CkUpload_putSsl(objHandle: HCkUpload; newPropVal: wordbool); stdcall;

Set this to True if the upload is to HTTPS. For example, if the target of the upload is:

https://www.myuploadtarget.com/consumeUpload.asp

then set:

Ssl = True
Hostname = "www.myuploadtarget.com"
Path = "/consumeupload.asp"
Port = 443

procedure CkUpload_getSslAllowedCiphers(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putSslAllowedCiphers(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__sslAllowedCiphers(objHandle: HCkUpload): PWideChar; stdcall;

Introduced in version 9.5.0.55

Provides a means for setting a list of ciphers that are allowed for SSL/TLS connections. The default (empty string) indicates that all implemented ciphers are possible. The TLS ciphers supported in Chilkat v9.5.0.55 and later are:

TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
TLS_DHE_RSA_WITH_AES_256_CBC_SHA
TLS_RSA_WITH_AES_256_CBC_SHA256
TLS_RSA_WITH_AES_256_GCM_SHA384
TLS_RSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
TLS_DHE_RSA_WITH_AES_128_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
TLS_RSA_WITH_AES_128_CBC_SHA
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA
TLS_RSA_WITH_3DES_EDE_CBC_SHA
TLS_ECDHE_RSA_WITH_RC4_128_SHA
TLS_RSA_WITH_RC4_128_SHA
TLS_RSA_WITH_RC4_128_MD5
TLS_DHE_RSA_WITH_DES_CBC_SHA
TLS_RSA_WITH_DES_CBC_SHA
To restrict SSL/TLS connections to one or more specific ciphers, set this property to a comma-separated list of ciphers such as "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384". The order should be in terms of preference, with the preferred algorithms listed first. (Note that the client cannot specifically choose the algorithm is picked because it is the server that chooses. The client simply provides the server with a list from which to choose.)

The property can also disallow connections with servers having certificates with RSA keys less than a certain size. By default, server certificates having RSA keys of 512 bits or greater are allowed. Add the keyword "rsa1024" to disallow connections with servers having keys smaller than 1024 bits. Add the keyword "rsa2048" to disallow connections with servers having keys smaller than 2048 bits.

Note: Prior to Chilkat v9.5.0.55, it was not possible to explicitly list allowed cipher suites. The deprecated means for indicating allowed ciphers was both incomplete and unprecise. For example, the following keywords could be listed to allow matching ciphers: "aes256-cbc", "aes128-cbc", "3des-cbc", and "rc4". These keywords will still be recognized, but programs should be updated to explicitly list the allowed ciphers.

secure-renegotiation: Starting in Chilkat v9.5.0.55, the keyword "secure-renegotiation" may be added to require that all renegotions be done securely (as per RFC 5746).

best-practices: Starting in Chilkat v9.5.0.55, this property may be set to the single keyword "best-practices". This will allow ciphers based on the current best practices. As new versions of Chilkat are released, the best practices may change. Changes will be noted here. The current best practices are:

  • If the server uses an RSA key, it must be 1024 bits or greater.
  • All renegotations must be secure renegotiations.
  • All ciphers using RC4, DES, or 3DES are disallowed.

Example: The following string would restrict to 2 specific cipher suites, require RSA keys to be 1024 bits or greater, and require secure renegotiations: "TLS_DHE_RSA_WITH_AES_256_CBC_SHA256, TLS_RSA_WITH_AES_256_CBC_SHA, rsa1024, secure-renegotiation"

procedure CkUpload_getSslProtocol(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putSslProtocol(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__sslProtocol(objHandle: HCkUpload): PWideChar; stdcall;

Introduced in version 9.5.0.55

Selects the secure protocol to be used for secure (SSL/TLS) connections. Possible values are:

default
TLS 1.2
TLS 1.1
TLS 1.0
SSL 3.0
TLS 1.2 or higher
TLS 1.1 or higher
TLS 1.0 or higher
The default value is "default" which will choose the, which allows for the protocol to be selected dynamically at runtime based on the requirements of the server. Choosing an exact protocol will cause the connection to fail unless that exact protocol is negotiated. It is better to choose "X or higher" than an exact protocol. The "default" is effectively "SSL 3.0 or higher".

procedure CkUpload_getTlsPinSet(objHandle: HCkUpload; outPropVal: HCkString); stdcall;
procedure CkUpload_putTlsPinSet(objHandle: HCkUpload; newPropVal: PWideChar); stdcall;

function CkUpload__tlsPinSet(objHandle: HCkUpload): PWideChar; stdcall;

Introduced in version 9.5.0.55

Specifies a set of pins for Public Key Pinning for TLS connections. This property lists the expected SPKI fingerprints for the server certificates. If the server's certificate (sent during the TLS handshake) does not match any of the SPKI fingerprints, then the TLS handshake is aborted and the connection fails. The format of this string property is as follows:

hash_algorithm, encoding, SPKI_fingerprint_1, SPKI_fingerprint_2, ...
For example, the following string specifies a single sha256 base64-encoded SPKI fingerprint:
"sha256, base64, lKg1SIqyhPSK19tlPbjl8s02yChsVTDklQpkMCHvsTE="
This example specifies two SPKI fingerprints:
"sha256, base64, 4t37LpnGmrMEAG8HEz9yIrnvJV2euVRwCLb9EH5WZyI=, 68b0G5iqMvWVWvUCjMuhLEyekM5729PadtnU5tdXZKs="
Any of the following hash algorithms are allowed:.sha1, sha256, sha384, sha512, md2, md5, haval, ripemd128, ripemd160,ripemd256, or ripemd320.

The following encodings are allowed: base64, hex, and any of the encodings indicated in the link below.

Encodings Supported by Chilkat

function CkUpload_getTotalUploadSize(objHandle: HCkUpload): LongWord; stdcall;

The total size of the upload (in bytes). This property will become set at the beginning of an asynchronous upload. A program may monitor asynchronous uploads by tracking both NumBytesSent and PercentUploaded.

This property is also set during synchronous uploads.

function CkUpload_getUploadInProgress(objHandle: HCkUpload): wordbool; stdcall;

Set to True when an asynchronous upload is started. When the asynchronous upload is complete, this property becomes equal to False. A program will typically begin an asynchronous upload by calling BeginUpload, and then periodically checking the value of this property to determine when the upload is complete.

function CkUpload_getUploadSuccess(objHandle: HCkUpload): wordbool; stdcall;

Set to True (success) or False (failed) after an asynchronous upload completes or aborts due to failure. When a program does an asynchronous upload, it will wait until UploadInProgress becomes False. It will then check the value of this property to determine if the upload was successful or not.

function CkUpload_getVerboseLogging(objHandle: HCkUpload): wordbool; stdcall;
procedure CkUpload_putVerboseLogging(objHandle: HCkUpload; newPropVal: wordbool); stdcall;

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

procedure CkUpload_getVersion(objHandle: HCkUpload; outPropVal: HCkString); stdcall;

function CkUpload__version(objHandle: HCkUpload): PWideChar; stdcall;

Version of the component/library, such as "9.4.1.42"

Methods

procedure CkUpload_AbortUpload(objHandle: HCkUpload); stdcall;

May be called during an asynchronous upload to abort.

procedure CkUpload_AddCustomHeader(objHandle: HCkUpload;
    name: PWideChar;
    value: PWideChar); stdcall;

Adds a custom HTTP header to the HTTP upload.

procedure CkUpload_AddFileReference(objHandle: HCkUpload;
    name: PWideChar;
    filename: PWideChar); stdcall;

Adds a file to the list of files to be uploaded in the next call to BlockingUpload, BeginUpload, or UploadToMemory. To upload more than one file, call this method once for each file to be uploaded.

procedure CkUpload_AddParam(objHandle: HCkUpload;
    name: PWideChar;
    value: PWideChar); stdcall;

Adds a custom HTTP request parameter to the upload.

function CkUpload_BeginUpload(objHandle: HCkUpload): wordbool; stdcall;

Starts an asynchronous upload. Only one asynchronous upload may be in progress at a time. To achieve multiple asynchronous uploads, use multiple instances of the Chilkat Upload object. Each object instance is capable of managing a single asynchronous upload.

When this method is called, a background thread is started and the asynchronous upload runs in the background. The upload may be aborted at any time by calling AbortUpload. The upload is completed (or failed) when UploadInProgress becomes False. At that point, the UploadSuccess property may be checked to determine success (True) or failure (False).

Returns True for success, False for failure.

Debugging HTTP Upload

Asynchronous HTTPS Upload Example

function CkUpload_BlockingUpload(objHandle: HCkUpload): wordbool; stdcall;

Uploads files to a web server using HTTP. The files to be uploaded are indicated by calling AddFileReference once for each file (prior to calling this method).

Returns True for success, False for failure.

Debugging HTTP Upload

IIS 7.0 Upload Size Limitations

IIS 6.0 Upload Size Limitations

BlockingUpload Example

function CkUpload_BlockingUploadAsync(objHandle: HCkUpload): HCkTask; stdcall;

Creates an asynchronous task to call the BlockingUpload method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

How to Run an Asynchronous Task

procedure CkUpload_ClearFileReferences(objHandle: HCkUpload); stdcall;

Clears the internal list of files created by calls to AddFileReference.

procedure CkUpload_ClearParams(objHandle: HCkUpload); stdcall;

Clears the internal list of params created by calls to AddParam.

function CkUpload_SaveLastError(objHandle: HCkUpload;
    path: PWideChar): wordbool; stdcall;

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

Returns True for success, False for failure.

procedure CkUpload_SleepMs(objHandle: HCkUpload;
    millisec: Integer); stdcall;

A convenience method for putting the calling process to sleep for N milliseconds. It is provided here because some programming languages do not provide this capability, and sleeping for short increments of time is helpful when doing asynchronous uploads.

function CkUpload_UploadToMemory(objHandle: HCkUpload;
    outData: HCkByteData): wordbool; stdcall;

Writes the complete HTTP POST to memory. The POST contains the HTTP header, any custom params added by calling AddParam, and each file to be uploaded. This is helpful in debugging. It allows you to see the exact HTTP POST sent to the server if BlockingUpload or BeginUpload is called.

Returns True for success, False for failure.