Hash Control

Properties   Methods   Events   Config Settings   Errors  

The Hash control allows you to compute a hash using various algorithms.

Syntax

Hash

Remarks

The Hash component allows you to compute a hash using various algorithms including SHA1, SHA224, SHA256, SHA384, SHA512, MD2, MD4, MD5, RIPEMD160, MD5SHA1, HMACMD5, HMACSHA1, HMACSHA224, HMACSHA256, HMACSHA384, HMACSHA512, etc.

To begin, first select the algorithm you wish to use when computing the hash. Common choices include MD5 and SHA1. For a full list of supported algorithms see the Algorithm property.

Next specify the data to hash. Input Notes

The control will determine the source of the input based on which properties are set.

The order in which the input properties are checked are as follows:

• InputFile
• InputMessage

When a valid source is found the search stops.

Call the ComputeHash method to hash the data. The HashValue property will hold the computed hash. By default the hash value is hex encoded for ease of use, but you may disable this by setting EncodeHash to False.

Property List

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The following is the full list of the properties of the control with short descriptions. Click on the links for further details.

Method List

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The following is the full list of the methods of the control with short descriptions. Click on the links for further details.

Event List

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The following is the full list of the events fired by the control with short descriptions. Click on the links for further details.

Config Settings

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The following is a list of config settings for the control with short descriptions. Click on the links for further details.

Algorithm Property (Hash Control)

The algorithm used to create the hash.

Syntax

hashcontrol.Algorithm[=integer]

Possible Values

haSHA1(0), 
haSHA224(1), 
haSHA256(2), 
haSHA384(3), 
haSHA512(4), 
haMD2(5), 
haMD4(6), 
haMD5(7), 
haRIPEMD160(8), 
haMD5SHA1(9), 
haHMACMD5(10), 
haHMACSHA1(11), 
haHMACSHA224(12), 
haHMACSHA256(13), 
haHMACSHA384(14), 
haHMACSHA512(15), 
haHMACRIPEMD160(16), 
haSHA3_224(17), 
haSHA3_256(18), 
haSHA3_384(19), 
haSHA3_512(20), 
haSHA512_224(21), 
haSHA512_256(22)

Default Value

2

Remarks

This property specifies the algorithm used when calling ComputeHash. Possible values are:

Data Type

Integer

EncodeHash Property (Hash Control)

Whether the hash value is hex encoded.

Syntax

hashcontrol.EncodeHash[=boolean]

Default Value

True

Remarks

This property specifies whether the computed hash value is hex encoded. When set to True (default) the control will hex encoded the computed hash for easier use. Set this value to False to obtain the hash value in an unmodified form.

The default value is True.

Data Type

Boolean

HashValue Property (Hash Control)

The hash value.

Syntax

hashcontrol.HashValue

Default Value

""

Remarks

The computed hash value. This property is populated after calling ComputeHash.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .HashValueB.

This property is read-only.

Data Type

Binary String

InputFile Property (Hash Control)

The file to process.

Syntax

hashcontrol.InputFile[=string]

Default Value

""

Remarks

This property specifies the file to be processed. Set this property to the full or relative path to the file which will be processed.

Input Notes

The control will determine the source of the input based on which properties are set.

The order in which the input properties are checked are as follows:

• InputFile
• InputMessage

When a valid source is found the search stops.

Data Type

String

InputMessage Property (Hash Control)

The message to process.

Syntax

hashcontrol.InputMessage[=string]

Default Value

""

Remarks

This property specifies the message to be processed.

Input Notes

The control will determine the source of the input based on which properties are set.

The order in which the input properties are checked are as follows:

• InputFile
• InputMessage

When a valid source is found the search stops.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .InputMessageB.

Data Type

Binary String

Key Property (Hash Control)

The secret key for the hash algorithm.

Syntax

hashcontrol.Key[=string]

Default Value

""

Remarks

This property holds the secret key used when creating the hash. The key can be arbitrarily long.

Note: This property is only applicable when Algorithm is set to an HMAC algorithm.

It is recommended that the length of the key be equal to or larger than the hash size of the algorithm. Use of keys shorter than the hash size is discouraged.

Sizes (in bytes)

Key Length Details

As mentioned above it is recommended to use a key size equal to the hash size. Use of keys larger than the hash size does not typically significantly increase the function strength. Keys of any length are technically valid however see the below processing rules to understand how keys of varying lengths are treated:

• If the key length is equal to the hash size (recommended) it is used without modification.
• If the key length is less than the hash size it is used without modification.
• If the key length is less than or equal to the block size it is used without modification.
• If the key length is larger than the block size is it first hashed with the same algorithm.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .KeyB.

Data Type

Binary String

ComputeHash Method (Hash Control)

Computes a hash.

Syntax

hashcontrol.ComputeHash 

Remarks

This method computes a hash of the data specified by InputMessage or InputFile. The algorithm used is specified by Algorithm. The HashValue property will be populated with the computed hash.

Input Notes

The control will determine the source of the input based on which properties are set.

The order in which the input properties are checked are as follows:

• InputFile
• InputMessage

When a valid source is found the search stops.

The Progress event will fire with updates during this operation.

Config Method (Hash Control)

Sets or retrieves a configuration setting.

Syntax

hashcontrol.Config ConfigurationString

Remarks

Config is a generic method available in every control. It is used to set and retrieve configuration settings for the control.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

HashBlock Method (Hash Control)

Computes the hash value of specified data.

Syntax

hashcontrol.HashBlock InputBuffer, LastBlock

Remarks

This method will compute the hash value of the input data. This method will return the hash value only when the parameter LastBlock is True.

InputBuffer specifies the input data.

LastBlock specifies whether the block is the last block. If this is False the method will return an empty byte array.

To calculate the hash value of data that is broken apart into multiple blocks make multiple calls to this method. For instance: Hash.HashBlock(part1,false); Hash.HashBlock(part2,false); Hash.HashBlock(part3,false); byte[] hashValue = Hash.HashBlock(lastPart,true);

Reset Method (Hash Control)

Resets the control.

Syntax

hashcontrol.Reset 

Remarks

When called, the control will reset all of its properties to their default values.

Error Event (Hash Control)

Fired when information is available about errors during data delivery.

Syntax

Sub hashcontrol_Error(ErrorCode As Integer, Description As String)

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the control fails with an error.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Progress Event (Hash Control)

Fired as progress is made.

Syntax

Sub hashcontrol_Progress(BytesProcessed As Long64, PercentProcessed As Integer)

Remarks

This event is fired automatically as data is processed by the control.

The PercentProcessed parameter indicates the current status of the operation.

The BytesProcessed parameter holds the total number of bytes processed so far.

Config Settings (Hash Control)

The control accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, access to these internal properties is provided through the Config method.

Hash Config Settings

Base Config Settings

Trappable Errors (Hash Control)

Hash Errors