AES Class

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The AES class can be used to encrypt and decrypt data through Advanced Encryption Standard (AES) cryptography.

Syntax

ipworksencrypt.Aes

Remarks

The AES component can be used to encrypt and decrypt data through Advanced Encryption Standard (AES) cryptography. Includes support for AES 128, 192, and 256 bit keys.

To begin simply specify the data you wish to encrypt or decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Before encrypting you must have a valid Key and IV. There are a few options available to you in regards to key management. The easiest option is to simply set KeyPassword. When KeyPassword is set the component will automatically create a Key and IV using the PKCS5 password digest algorithm. This means there is only one value you need to keep track of.

If you wish to have more control over the Key and IV values you may specify the properties yourself. If IV is left empty, one will be created for you when you call Encrypt or Decrypt.

A simple example: Component.InputFile = "C:\MyFile.txt"; Component.OutputFile = "C:\Encrypted.txt"; Component.KeyPassword = "password"; Component.Encrypt();

Note that by default the component uses a key size of 256. You may specify the key size (such as 128 or 192) by setting KeySize.

Property List

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

CipherMode Property (AES Class)

The cipher mode of operation.

Syntax

public int getCipherMode();


public void setCipherMode(int cipherMode);


Enumerated values:
  public final static int acmCBC = 0;
  public final static int acmECB = 1;
  public final static int acmOFB = 2;
  public final static int acmCFB = 3;
  public final static int acmCTS = 4;
  public final static int acm8OFB = 5;
  public final static int acmGCM = 6;
  public final static int acm8CFB = 7;
  public final static int acmCTR = 8;
  public final static int acmXTS = 9;

Default Value

0

Remarks

The cipher mode of operation.

Possible values are:

GCM Notes

When setting this value to 6 (acmGCM) the following settings are also applicable:

• AdditionalAuthData
• AuthTag
• AuthTagLength

GCM mode code example: //Encrypt aes.CipherMode = AesCipherModes.acmGCM; aes.KeyPassword = "test"; aes.InputMessage = "input data"; aes.Config("AdditionalData=" + hex_aad); //Optional aes.Encrypt(); string authTag = aes.Config("AuthTag"); byte[] outputMessage = aes.OutputMessageB; //Decrypt aes.CipherMode = AesCipherModes.acmGCM; aes.KeyPassword = "test"; aes.InputMessageB = outputMessage; aes.Config("AdditionalData=" + hex_aa); aes.Config("AuthenticationTag=" + authTag); aes.Decrypt(); XTS Notes

When setting this value to 9 (acmXTS) the following settings are also applicable:

• UsePlatformAES
• XTSDataUnitLength
• XTSInitialTweak

PaddingMode has no effect when using acmXTS -- the InputMessage MUST be a multiple of XTSDataUnitLength.

InputFile Property (AES Class)

The file to process.

Syntax

public String getInputFile();


public void setInputFile(String 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 and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

InputMessage Property (AES Class)

The message to process.

Syntax

public byte[] getInputMessage();


public void setInputMessage(byte[] inputMessage);

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

IV Property (AES Class)

The initialization vector (IV).

Syntax

public byte[] getIV();


public void setIV(byte[] IV);

Default Value

""

Remarks

This property specifies the initialization vector (IV). By default this property is empty and the class will automatically generate a new IV value if KeyPassword or Key is set before Encrypt or EncryptBlock is called. The size of the IV property must be equal to the BlockSize divided by 8.

Key Property (AES Class)

The secret key for the symmetric algorithm.

Syntax

public byte[] getKey();


public void setKey(byte[] key);

Default Value

""

Remarks

This secret key is used both for encryption and decryption. The secret key should be known only to the sender and the receiver. The legal key size varies depending on the algorithm.

If this property is left empty and KeyPassword is specified, a Key value will be generated by the class as necessary.

Legal Key and Block Sizes (in bits)

Note: When using TEA if Algorithm is set to XXTEA valid block sizes are 64 + n * 32. Where n is any positive integer.

The default KeySize is the Maximum Key Size.

KeyPassword Property (AES Class)

A password to generate the Key and IV .

Syntax

public String getKeyPassword();


public void setKeyPassword(String keyPassword);

Default Value

""

Remarks

When this property is set the class will calculate values for Key and IV using the PKCS5 password digest algorithm. This provides a simpler alternative to creating and managing Key and IV values directly.

The size of the Key generated is dependent on the value of KeySize.

OutputFile Property (AES Class)

The output file when encrypting or decrypting.

Syntax

public String getOutputFile();


public void setOutputFile(String outputFile);

Default Value

""

Remarks

This property specifies the file to which the output will be written when Encrypt or Decrypt is called. This may be set to an absolute or relative path.

This property is only applicable to Encrypt and Decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

OutputMessage Property (AES Class)

The output message after processing.

Syntax

public byte[] getOutputMessage();

Default Value

""

Remarks

This property will be populated with the output from the operation if OutputFile and SetOutputStream are not set.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

This property is read-only and not available at design time.

Overwrite Property (AES Class)

Indicates whether or not the class should overwrite files.

Syntax

public boolean isOverwrite();


public void setOverwrite(boolean overwrite);

Default Value

False

Remarks

This property indicates whether or not the class will overwrite OutputFile. If Overwrite is False, an error will be thrown whenever OutputFile exists before an operation. The default value is False.

PaddingMode Property (AES Class)

The padding mode.

Syntax

public int getPaddingMode();


public void setPaddingMode(int paddingMode);


Enumerated values:
  public final static int pmPKCS7 = 0;
  public final static int pmZeros = 1;
  public final static int pmNone = 2;
  public final static int pmANSIX923 = 3;
  public final static int pmISO10126 = 4;

Default Value

0

Remarks

PaddingMode is used to pad the final input block to guarantee that it is the correct size required for the selected CipherMode. If the input size is a multiple of the cipher's BlockSize, an extra block of padding will be appended to the input. This enables the decrypting agent to know with certainty how many bytes of padding are included. Each mode pads the data differently. Possible values are:

When calling Decrypt the PaddingMode must match the value used when the data was encrypted.

Note: When using a value of 2 (pmNone), unless the length of input is an exact multiple of the cipher's input BlockSize, the final block of plaintext may be lost.

UseHex Property (AES Class)

Whether input or output is hex encoded.

Syntax

public boolean isUseHex();


public void setUseHex(boolean useHex);

Default Value

False

Remarks

This property specifies whether the encrypted data is hex encoded.

If set to True, when Encrypt is called the class will perform the encryption as normal and then hex encode the output. OutputMessage or OutputFile will hold hex encoded data.

If set to True, when Decrypt is called the class will expect InputMessage or InputFile to hold hex encoded data. The class will then hex decode the data and perform decryption as normal.

Config Method (Aes Class)

Sets or retrieves a configuration setting.

Syntax

public String config(String configurationString);

Remarks

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

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

Decrypt Method (Aes Class)

Decrypts the data.

Syntax

public void decrypt();

Remarks

This method will decrypt the specified data. The following properties are applicable:

• IV (required)
• Key (required)
• CipherMode
• PaddingMode

Note that CipherMode must be set to the same value used during encryption or the results may be unexpected. If the CipherMode value does not match the value used during encryption the operation may succeed but the decrypted data may not be correct.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

DecryptBlock Method (Aes Class)

Decrypts a block and returns the decrypted data.

Syntax

public byte[] decryptBlock(byte[] inputBuffer, boolean lastBlock);

Remarks

This method will decrypt the specified block and return the decrypted data.

InputBuffer specifies the encrypted block to decrypt.

LastBlock indicates whether the block is the last block.

Encrypt Method (Aes Class)

Encrypts the data.

Syntax

public void encrypt();

Remarks

This method will encrypt the specified data. The following properties are applicable:

• IV (required)
• Key (required)
• PaddingMode
• CipherMode

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

EncryptBlock Method (Aes Class)

Encrypts data and returns the encrypted block.

Syntax

public byte[] encryptBlock(byte[] inputBuffer, boolean lastBlock);

Remarks

This method will encrypt the input data and return the encrypted block.

InputBuffer specifies the input data to encrypt.

LastBlock specifies whether the block is the last block.

Reset Method (Aes Class)

Resets the class.

Syntax

public void reset();

Remarks

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

SetInputStream Method (Aes Class)

Sets the stream from which the class will read data to encrypt or decrypt.

Syntax

public void setInputStream(java.io.InputStream inputStream);

Remarks

This method sets the stream from which the class will read data to encrypt or decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

SetOutputStream Method (Aes Class)

Sets the stream to which the class will write encrypted or decrypted data.

Syntax

public void setOutputStream(java.io.OutputStream outputStream);

Remarks

This method sets the stream to which the class will write encrypted or decrypted data.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

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

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Error Event (Aes Class)

Fired when information is available about errors during data delivery.

Syntax

public class DefaultAesEventListener implements AesEventListener {
  ...
  public void error(AesErrorEvent e) {}
  ...
}

public class AesErrorEvent {
  public int errorCode;
  public String description;
}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class throws 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 (Aes Class)

Fired as progress is made.

Syntax

public class DefaultAesEventListener implements AesEventListener {
  ...
  public void progress(AesProgressEvent e) {}
  ...
}

public class AesProgressEvent {
  public long bytesProcessed;
  public int percentProcessed;
}

Remarks

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

The PercentProcessed parameter indicates the current status of the operation.

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

Config Settings (Aes Class)

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

AES Config Settings

Base Config Settings

Trappable Errors (Aes Class)

AES Errors

	101   Unsupported algorithm.
	102   No Key specified.
	103   No IV specified.
	104   Cannot read or write file.
	107   Block size is not valid for this algorithm.
	108   Key size is not valid for this algorithm.
	111   OutputFile already exists and Overwrite is False.
	121   The specified key is invalid.
	123   IV size is not valid for this algorithm.
	304   Cannot write file.
	305   Cannot read file.
	306   Cannot create file.
	2004   Invalid padding. This may be an indication that the key is incorrect.