HashFunction Component

Properties   Methods   Events   Config Settings   Errors  

The HashFunction component implements a wide variety of algorithms for message hashing.

Syntax

TsbxHashFunction

Remarks

HashFunction allows you to hash messages using a variety of industry standard hashing algorithms. Algorithms of both Hash and HMAC type are supported.

You can feed your data to HashFunction in one go, or in chunks. Use Hash method to initialize the hash function, pass the buffer, and calculate the hash in one line of code. Alternatively, use Reset, Update, and Finish in sequence to perform each of those steps individually. You can call Update (and its UpdateFile and UpdateStream variants) repeatedly between Reset and Finish, effectively passing the data in a number of portions: // Feeding the data in one go: Hashfunction hf = new Hashfunction(); hf.Algorithm = "SHA256"; byte[] hash = hf.Hash(buffer); // Feeding data chunk by chunk: Hashfunction hf = new Hashfunction(); hf.Algorithm = "SHA256"; hf.Reset(); hf.Update(buffer1); hf.Update(buffer2); hf.Update(buffer3); byte[] hash = hf.Finish();

To use keyed HMAC, you need to provide the secret key first. Use CryptoKeyManager to create and initialize the key object: Cryptokeymanager km = new Cryptokeymanager(); km.ImportBytes(hmacKey, Constants.kffDER, "SHA256", "", "", Constants.ktSecret); Hashfunction hf = new Hashfunction(); hf.Algorithm = "SHA256"; hf.Key = km.Key; byte[] hash = hf.Hash(buffer);

Use OutputEncoding to set the desired encoding method.

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 (HashFunction Component)

The hash algorithm to use when hashing data.

Syntax

property Algorithm: String read get_Algorithm write set_Algorithm;

Default Value

'SHA256'

Remarks

FIPSMode Property (HashFunction Component)

Reserved.

Syntax

property FIPSMode: Boolean read get_FIPSMode write set_FIPSMode;

Default Value

false

Remarks

This property is reserved for future use.

JsonSettings Property (HashFunction Component)

Provides a container for JSON settings.

Syntax

property JsonSettings: TsbxJWSettings read get_JsonSettings;

Remarks

Use this property when using JSON Web Signatures to tune up the JSON parameters.

This property is read-only.

Please refer to the JWSettings type for a complete list of fields.

Key Property (HashFunction Component)

The key to use during the hashing.

Syntax

property Key: TsbxCryptoKey read get_Key write set_Key;

Remarks

Assign a properly configured cryptographic key object to this property to use it during the hashing operation. This would normally be a HMAC key.

This property is not available at design time.

Please refer to the CryptoKey type for a complete list of fields.

OutputEncoding Property (HashFunction Component)

The encoding to use for the output data.

Syntax

property OutputEncoding: TsbxCryptoEncodingTypes read get_OutputEncoding write set_OutputEncoding;

TsbxCryptoEncodingTypes = (
  cetDefault,
  cetBinary,
  cetBase64,
  cetCompact,
  cetJSON
);

Default Value

cetDefault

Remarks

Use this property to configure the type of encoding to be used for the output data.

Config Method (HashFunction 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.

DoAction Method (HashFunction Component)

Performs an additional action.

Syntax

function DoAction(ActionID: String; ActionParams: String): String;

Remarks

DoAction is a generic method available in every component. It is used to perform an additional action introduced after the product major release. The list of actions is not fixed, and may be flexibly extended over time.

The unique identifier (case insensitive) of the action is provided in the ActionID parameter.

ActionParams contains the value of a single parameter, or a list of multiple parameters for the action in the form of PARAM1=VALUE1;PARAM2=VALUE2;....

Finish Method (HashFunction Component)

Completes the hash and returns the resulting message digest.

Syntax

function Finish(): TBytes;

Remarks

This method finalizes the hashing operation and returns the message digest of the input data. Use it in conjuction with Reset and Update methods to process data in chunks.

Hash Method (HashFunction Component)

Calculates a message digest over a byte array.

Syntax

function Hash(Buffer: TBytes): TBytes;

Remarks

This method calculates and returns a message digest over the content of Buffer. This is a quick way to calculate a hash over a byte array in one go.

HashFile Method (HashFunction Component)

Calculates a message digest over data contained in a file.

Syntax

function HashFile(SourceFile: String): TBytes;

Remarks

This method calculates and returns a message digest over the data contained in file SourceFile. This is a quick way to calculate a hash over a file content in one go.

HashStream Method (HashFunction Component)

Calculates a message digest over data contained in a stream.

Syntax

function HashStream(): TBytes;

Remarks

This method calculates a message digest over the data contained in InputStream. This is a quick way of calculating a message data over a stream content in one go.

Reset Method (HashFunction Component)

Resets the hash function context.

Syntax

procedure Reset();

Remarks

Reset resets the context of the hash function, discarding any data passed to it previously.

Use this method to restart the hash calculation process from scratch.

This method does not affect one-go methods like Hash or HashStream; they reset the hash function context automatically.

Update Method (HashFunction Component)

Feeds a chunk of data to the hash function.

Syntax

procedure Update(Buffer: TBytes);

Remarks

This method feeds Buffer to the hash function. Call this method repeatedly to pass your data to the hash function chunk by chunk.

Remember to initialize the hash function with an Reset call before starting to feed data with this method. After the whole volume of data has been sent, complete the calculation and obtain the resulting message digest with a Finish call.

UpdateFile Method (HashFunction Component)

Feeds the contents of a file to the hash function.

Syntax

procedure UpdateFile(SourceFile: String);

Remarks

Call this method to pass the contents of a file to the hash function. You can call this function repeatedly and mix it with Update to feed the hash function with many separate chunks of data.

Remember to initialize the hash function with an Reset call before starting hashing the data. Once all the data chunks have been submitted, finalize the hash function and obtain the resulting message digest by calling Finish.

UpdateStream Method (HashFunction Component)

Feeds the contents of a stream to the hash function.

Syntax

procedure UpdateStream();

Remarks

Call this method to pass the contents of a stream to the hash function. You can call this function repeatedly and mix it with Update to feed the hash function with many separate chunks of data.

Remember to initialize the hash function with an Reset call before starting hashing the data. Once all the data chunks have been submitted, finalize the hash function and obtain the resulting message digest by calling Finish.

Error Event (HashFunction Component)

Informs about errors during cryptographic operations.

Syntax

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

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

Component fires this event if an error happens during a cryptographic operation.

ErrorCode contains an error code and Description contains a textual description of the error that happened.

Notification Event (HashFunction Component)

This event notifies the application about an underlying control flow event.

Syntax

type TNotificationEvent = procedure (
  Sender: TObject;
  const EventID: String;
  const EventParam: String
) of Object;

property OnNotification: TNotificationEvent read FOnNotification write FOnNotification;

Remarks

The component fires this event to let the application know about some event, occurrence, or milestone in the component. For example, it may fire to report completion of the document processing. The list of events being reported is not fixed, and may be flexibly extended over time.

The unique identifier of the event is provided in the EventID parameter. EventParam contains any parameters accompanying the occurrence. Depending on the type of the component, the exact action it is performing, or the document being processed, one or both may be omitted.

CryptoKey Type

This container represents a cryptographic key.

Remarks

This type is a universal placeholder for cryptographic keys.

Fields

Constructors

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constructor Create();

JWSettings Type

This container represents JSON web security settings.

Remarks

This type contains properties specific to JSON Web Security.

Fields

Constructors

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constructor Create();

Config Settings (HashFunction 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.

HashFunction Config Settings

Base Config Settings

Trappable Errors (HashFunction Component)

HashFunction Errors