Hash Component

Properties   Methods   Events   Config Settings   Errors  

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

Syntax

TipcHash

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 component 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 component 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 component 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 component 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 component with short descriptions. Click on the links for further details.

Algorithm Property (Hash Component)

The algorithm used to create the hash.

Syntax

property Algorithm: TipcTHASHAlgorithms read get_Algorithm write set_Algorithm;

TipcTHASHAlgorithms = (
  haSHA1,
  haSHA224,
  haSHA256,
  haSHA384,
  haSHA512,
  haMD2,
  haMD4,
  haMD5,
  haRIPEMD160,
  haMD5SHA1,
  haHMACMD5,
  haHMACSHA1,
  haHMACSHA224,
  haHMACSHA256,
  haHMACSHA384,
  haHMACSHA512,
  haHMACRIPEMD160,
  haSHA3_224,
  haSHA3_256,
  haSHA3_384,
  haSHA3_512,
  haSHA512_224,
  haSHA512_256
);

Default Value

haSHA256

Remarks

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

EncodeHash Property (Hash Component)

Whether the hash value is hex encoded.

Syntax

property EncodeHash: Boolean read get_EncodeHash write set_EncodeHash;

Default Value

true

Remarks

This property specifies whether the computed hash value is hex encoded. When set to True (default) the component 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.

HashValue Property (Hash Component)

The hash value.

Syntax

property HashValue: String read get_HashValue;
property HashValueB: TBytes read get_HashValueB;

Default Value

''

Remarks

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

This property is read-only.

InputFile Property (Hash Component)

The file to process.

Syntax

property InputFile: String read get_InputFile write set_InputFile;

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 component 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.

InputMessage Property (Hash Component)

The message to process.

Syntax

property InputMessage: String read get_InputMessage write set_InputMessage;
property InputMessageB: TBytes read get_InputMessageB write set_InputMessageB;

Default Value

''

Remarks

This property specifies the message to be processed.

Input Notes

The component 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.

Key Property (Hash Component)

The secret key for the hash algorithm.

Syntax

property Key: String read get_Key write set_Key;
property KeyB: TBytes read get_KeyB write set_KeyB;

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.

ComputeHash Method (Hash Component)

Computes a hash.

Syntax

procedure 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 component 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 Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): String;

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, 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 Component)

Computes the hash value of specified data.

Syntax

function HashBlock(InputBuffer: TBytes; LastBlock: Boolean): TBytes;

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 Component)

Resets the component.

Syntax

procedure Reset();

Remarks

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

SetInputStream Method (Hash Component)

Sets the stream from which the component will read data.

Syntax

procedure SetInputStream(InputStream: TStream);

Remarks

This method sets the stream from which the component will read data.

Input Notes

The component 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.

Error Event (Hash Component)

Fired when information is available about errors during data delivery.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component raises an exception.

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 Component)

Fired as progress is made.

Syntax

type TProgressEvent = procedure (
  Sender: TObject;
  BytesProcessed: Int64;
  PercentProcessed: Integer
) of Object;

property OnProgress: TProgressEvent read FOnProgress write FOnProgress;

Remarks

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

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 Component)

The component 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 component, access to these internal properties is provided through the Config method.

Hash Config Settings

Base Config Settings

Trappable Errors (Hash Component)

Hash Errors