AESFile Component
Properties Methods Events Config Settings Errors
The AESFile component implements the AESF file format and uses the XTS-AES standard with 256-bit encryption.
Syntax
nsoftware.IPWorksEncrypt.AESFile
Remarks
The AESFile component provides robust encryption capabilities to securely store and retrieve data using XTS-AES 256-bit encryption. This component implements the AESF file format, enabling developers to encrypt arbitrary data and serialize it in a standardized manner.
The first step in using the component is to set Password property. Specify the input data using InputFile or InputMessage. Next, call Encrypt and the component will encrypt the input data and populate OutputMessage, or write to the file specified by OutputFile with the result.
To change the password of existing file encrypted in AESF format, or to encrypt a file under a different password call ChangePassword. To decrypt data, first set Password property. Specify the input data using InputFile or InputMessage. Next, call Decrypt and the component will compute the plaintext and populate OutputMessage or write to OutputFile with the result.
AES File Format
The AES file format used by AES Drive is documented below in detail. All algorithms used by AES Drive are standards and publicly documented.
Each encrypted file consists of a header and the encrypted contents. The header is 144 bytes in length and contains the AES file format version, a checksum of the header bytes, and the encrypted file-specific key and padding length. The original file data is encrypted using XTS-AES with file-specific keys that are derived from a master key for the drive.
4 bytes [0-3] | AESF. This is a file signature value which indicates the file is formatted according to this specification. | ||||||||
1 byte [4] | 0x01. This is the file format version. This documentation defines the format for version 1. | ||||||||
2 bytes [5-6] | Build number of the application used to create the file. These two bytes represent a 16-bit integer holding the build number of AES Drive that created the file. This field is informational only. Byte 5 holds the high-order bits and byte 6 holds the low-order bits. To decode these bytes into the build number the following code may be used:
int buildNumber = headerBytes[5] << 8 | headerBytes[6];
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5 bytes [7-11] | 0x00. Reserved for future use. | ||||||||
4 bytes [12-15] | CRC32 checksum. The CRC32 checksum is calculated by first replacing these 4 bytes with 0x00 then computing the checksum over the 144 byte header. The resulting numeric value is converted into 4 bytes using the operation:
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16 bytes [16-31] | Global salt value. The global salt value is a random value created when the drive is created and used when encrypting newly created files within the drive. It is used when deriving the key to decrypt the encrypted header portion. See the section below for details about the encrypted header portion. | ||||||||
16 bytes [32-47] | File-specific salt value. The file-specific salt value is a random value created when the file is created. It is used when deriving the key to decrypt the encrypted header portion. See the section below for details about the encrypted header portion. | ||||||||
80 bytes [48-127] | AES-GCM encrypted header portion. The steps to derive the key to decrypt the encrypted header portion are as follows:
The derived Key and IV are used together with the AES-GCM Auth Tag which are the last 16 bytes of the 144 byte header to AES-GCM decrypt the 80 byte encrypted header portion. The decrypted header portion contains:
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16 bytes [128-143] | AES-GCM auth tag. This auth tag is used when decrypting the previous 80 byte encrypted header portion. | ||||||||
nn bytes | The XTS-AES 256 encrypted file content. The data unit size is 512 bytes. The first 32 bytes of the file-specific encryption key from the decrypted header is the first key. The last 32 bytes of the file-specific encryption key from the decrypted header is the second key. | ||||||||
512 bytes |
The last 512 bytes of the encrypted file contain encrypted padding bytes and additional unencrypted random bytes. When encrypting, the last plaintext block of data may be padded with random bytes as needed to reach 512 bytes in length (the data unit size). The padding length is encrypted and stored in the encrypted header portion. Once the data is encrypted additional random bytes are appended to the end of the encrypted file so that the padding bytes plus additional random bytes together are 512 bytes in length. For instance if the padding is 100 bytes in length, then 412 additional bytes will be appended to the encrypted data to reach a total of 512 bytes. This scheme allows applications to easily determine the length of the decrypted file without having to first decrypt the encrypted header portion to obtain the padding length. The decrypted file length can be computed like so:
When decrypting, the padding length is determined from the encrypted header. The number of additional random bytes is 512 minus the padding length. The additional random bytes are discarded before using XTS-AES to decrypt the file content. After decrypting the file content, the padding bytes in the decrypted content are discarded.
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Property List
The following is the full list of the properties of the component with short descriptions. Click on the links for further details.
GlobalSalt | The additional random data to compute encryption keys. |
InputFile | The file to process. |
InputMessage | The message to process. |
OutputFile | The output file when encrypting or decrypting. |
OutputMessage | The output message after processing. |
Overwrite | Indicates whether or not the component should overwrite files. |
Password | The password to be used to calculate encryption and decryption keys. |
Salt | The additional random data included in the file header. |
Version | The AESF file format version number. |
Method List
The following is the full list of the methods of the component with short descriptions. Click on the links for further details.
ChangePassword | Changes the password for the specified file. |
Config | Sets or retrieves a configuration setting. |
Decrypt | Decrypts the data. |
Encrypt | Encrypts the data. |
Reset | Resets the component. |
SetInputStream | Sets the stream from which the component will read data to encrypt or decrypt. |
SetOutputStream | Sets the stream to which the component will write encrypted or decrypted data. |
Event List
The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.
Error | Fired when information is available about errors during data delivery. |
Log | Fires with log information during processing. |
Progress | Fired as progress is made. |
Config Settings
The following is a list of config settings for the component with short descriptions. Click on the links for further details.
BuildNumber | The build number of the encrypted data. |
CloseInputStreamAfterProcessing | Determines whether or not the input stream is closed after processing. |
CloseOutputStreamAfterProcessing | Determines whether or not the output stream is closed after processing. |
LogLevel | Specifies the level of detail that is logged. |
WriteToProgressEvent | Whether to write output data so it is accessible from inside the progress event. |
BuildInfo | Information about the product's build. |
GUIAvailable | Whether or not a message loop is available for processing events. |
LicenseInfo | Information about the current license. |
MaskSensitiveData | Whether sensitive data is masked in log messages. |
UseFIPSCompliantAPI | Tells the component whether or not to use FIPS certified APIs. |
UseInternalSecurityAPI | Whether or not to use the system security libraries or an internal implementation. |
GlobalSalt Property (AESFile Component)
The additional random data to compute encryption keys.
Syntax
Default Value
""
Remarks
This is an optional property and will be populated when Decrypt is called. When this property is set, it will provide additional randomness to encryption. The length of the salt must be 16 bytes.
The global salt will be used during generation of a key and IV. It can optionally be set before calling the Encrypt method. It is recommended to use a unique and randomly generated value. If it is not set, then the component will generate a value automatically.
InputFile Property (AESFile Component)
The file to process.
Syntax
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 component 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 (AESFile Component)
The message to process.
Syntax
Default Value
""
Remarks
This property specifies the message to be processed.
Input and Output Properties
The component 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.
OutputFile Property (AESFile Component)
The output file when encrypting or decrypting.
Syntax
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 component 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:
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 (AESFile Component)
The output message after processing.
Syntax
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 component 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:
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 (AESFile Component)
Indicates whether or not the component should overwrite files.
Syntax
Default Value
False
Remarks
This property indicates whether or not the component will overwrite OutputFile. If Overwrite is False, an error will be thrown whenever OutputFile exists before an operation. The default value is False.
Password Property (AESFile Component)
The password to be used to calculate encryption and decryption keys.
Syntax
Default Value
""
Remarks
When this property is set the component will use PBKDF2 to derive an XTS master key. This must be set before calling Encrypt or Decrypt.
While there are no strict format or length requirements, it is recommended to use complex passwords. Once set, the password is transformed and never held in plaintext in memory.
Salt Property (AESFile Component)
The additional random data included in the file header.
Syntax
Default Value
""
Remarks
This property is optional and will be populated when Decrypt is called. When this property is set it will provide additional randomness to encryption at the file level. The length of the salt must be 16 bytes.
The salt will be used within each file as input to encryption. It can optionally be set before calling the Encrypt method. It is recommended to use a unique and randomly generated value. If it is not set, then the component will generate a value automatically.
Version Property (AESFile Component)
The AESF file format version number.
Syntax
Default Value
1
Remarks
This property will be populated when Decrypt is called. Possible values are:
1 (v1 - Default) |
ChangePassword Method (AESFile Component)
Changes the password for the specified file.
Syntax
public void ChangePassword(string path, string oldPassword, string newPassword); Async Version public async Task ChangePassword(string path, string oldPassword, string newPassword); public async Task ChangePassword(string path, string oldPassword, string newPassword, CancellationToken cancellationToken);
Public Sub ChangePassword(ByVal Path As String, ByVal OldPassword As String, ByVal NewPassword As String) Async Version Public Sub ChangePassword(ByVal Path As String, ByVal OldPassword As String, ByVal NewPassword As String) As Task Public Sub ChangePassword(ByVal Path As String, ByVal OldPassword As String, ByVal NewPassword As String, cancellationToken As CancellationToken) As Task
Remarks
ChangePassword is optional and allows you to update the password used to encrypt an AESF file. This securely changes the password, ensuring that the file remains protected with the new password.
Config Method (AESFile Component)
Sets or retrieves a configuration setting.
Syntax
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.
Decrypt Method (AESFile Component)
Decrypts the data.
Syntax
public void Decrypt(); Async Version public async Task Decrypt(); public async Task Decrypt(CancellationToken cancellationToken);
Public Sub Decrypt() Async Version Public Sub Decrypt() As Task Public Sub Decrypt(cancellationToken As CancellationToken) As Task
Remarks
This method will decrypt the specified data. The Password property is required.
Input and Output Properties
The component 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:
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.
Encrypt Method (AESFile Component)
Encrypts the data.
Syntax
public void Encrypt(); Async Version public async Task Encrypt(); public async Task Encrypt(CancellationToken cancellationToken);
Public Sub Encrypt() Async Version Public Sub Encrypt() As Task Public Sub Encrypt(cancellationToken As CancellationToken) As Task
Remarks
This method will encrypt the specified data. The following properties are applicable:
- Password (required)
- GlobalSalt
- Version
Input and Output Properties
The component 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:
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.
Reset Method (AESFile Component)
Resets the component.
Syntax
public void Reset(); Async Version public async Task Reset(); public async Task Reset(CancellationToken cancellationToken);
Public Sub Reset() Async Version Public Sub Reset() As Task Public Sub Reset(cancellationToken As CancellationToken) As Task
Remarks
When called, the component will reset all of its properties to their default values.
SetInputStream Method (AESFile Component)
Sets the stream from which the component will read data to encrypt or decrypt.
Syntax
public void SetInputStream(System.IO.Stream inputStream); Async Version public async Task SetInputStream(System.IO.Stream inputStream); public async Task SetInputStream(System.IO.Stream inputStream, CancellationToken cancellationToken);
Public Sub SetInputStream(ByVal InputStream As System.IO.Stream) Async Version Public Sub SetInputStream(ByVal InputStream As System.IO.Stream) As Task Public Sub SetInputStream(ByVal InputStream As System.IO.Stream, cancellationToken As CancellationToken) As Task
Remarks
This method sets the stream from which the component will read data to encrypt or decrypt.
Input and Output Properties
The component 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 (AESFile Component)
Sets the stream to which the component will write encrypted or decrypted data.
Syntax
public void SetOutputStream(System.IO.Stream outputStream); Async Version public async Task SetOutputStream(System.IO.Stream outputStream); public async Task SetOutputStream(System.IO.Stream outputStream, CancellationToken cancellationToken);
Public Sub SetOutputStream(ByVal OutputStream As System.IO.Stream) Async Version Public Sub SetOutputStream(ByVal OutputStream As System.IO.Stream) As Task Public Sub SetOutputStream(ByVal OutputStream As System.IO.Stream, cancellationToken As CancellationToken) As Task
Remarks
This method sets the stream to which the component will write encrypted or decrypted data.
Input and Output Properties
The component 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:
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 (AESFile Component)
Fired when information is available about errors during data delivery.
Syntax
public event OnErrorHandler OnError; public delegate void OnErrorHandler(object sender, AESFileErrorEventArgs e); public class AESFileErrorEventArgs : EventArgs { public int ErrorCode { get; } public string Description { get; } }
Public Event OnError As OnErrorHandler Public Delegate Sub OnErrorHandler(sender As Object, e As AESFileErrorEventArgs) Public Class AESFileErrorEventArgs Inherits EventArgs Public ReadOnly Property ErrorCode As Integer Public ReadOnly Property Description As String End Class
Remarks
The Error event is fired in case of exceptional conditions during message processing. Normally the component 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.
Log Event (AESFile Component)
Fires with log information during processing.
Syntax
public event OnLogHandler OnLog; public delegate void OnLogHandler(object sender, AESFileLogEventArgs e); public class AESFileLogEventArgs : EventArgs { public int LogLevel { get; } public string Message { get; } public string LogType { get; } }
Public Event OnLog As OnLogHandler Public Delegate Sub OnLogHandler(sender As Object, e As AESFileLogEventArgs) Public Class AESFileLogEventArgs Inherits EventArgs Public ReadOnly Property LogLevel As Integer Public ReadOnly Property Message As String Public ReadOnly Property LogType As String End Class
Remarks
This event fires during processing with log information. The level of detail that is logged is controlled via the LogLevel.
LogLevel indicates the level of message. Possible values are:
0 (None) | No events are logged. |
1 (Info - default) | Informational events are logged. |
2 (Verbose) | Detailed data is logged. |
3 (Debug) | Debug data is logged. |
LogMessage is the log entry.
LogType indicates the type of log. Possible values are:
- "INFO"
- "ENCRYPT"
- "COMPRESS"
- "SIGN"
- "DECRYPT"
- "DECOMPRESS"
- "VERIFY"
- "DEBUG"
Progress Event (AESFile Component)
Fired as progress is made.
Syntax
public event OnProgressHandler OnProgress; public delegate void OnProgressHandler(object sender, AESFileProgressEventArgs e); public class AESFileProgressEventArgs : EventArgs { public string Data { get; }
public byte[] DataB { get; } public string Filename { get; } public long BytesProcessed { get; } public int PercentProcessed { get; } }
Public Event OnProgress As OnProgressHandler Public Delegate Sub OnProgressHandler(sender As Object, e As AESFileProgressEventArgs) Public Class AESFileProgressEventArgs Inherits EventArgs Public ReadOnly Property Data As String
Public ReadOnly Property DataB As Byte() Public ReadOnly Property Filename As String Public ReadOnly Property BytesProcessed As Long Public ReadOnly Property PercentProcessed As Integer End Class
Remarks
This event is fired automatically as data is encrypted or decrypted by the component. When WriteToProgressEvent is true, the output data is provided through the Data parameter, allowing for it to be streamed out.
Filename contains the name of the file being written. If no file is being written, Filename will contain an empty string, and the output data will be provided exclusively through this event.
The PercentProcessed parameter indicates the current status of the operation.
The BytesProcessed parameter holds the total number of bytes processed so far.
Config Settings (AESFile 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.AESFile Config Settings
0 (None) | No events are logged. |
1 (Info - default) | Informational events are logged. |
2 (Verbose) | Detailed data is logged. |
3 (Debug) | Debug data is logged. |
By default, this config is set to false.
Base Config Settings
In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the component does not attempt to process external events.
- Product: The product the license is for.
- Product Key: The key the license was generated from.
- License Source: Where the license was found (e.g., RuntimeLicense, License File).
- License Type: The type of license installed (e.g., Royalty Free, Single Server).
- Last Valid Build: The last valid build number for which the license will work.
This setting only works on these components: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.
FIPS mode can be enabled by setting the UseFIPSCompliantAPI configuration setting to true. This is a static setting that applies to all instances of all components of the toolkit within the process. It is recommended to enable or disable this setting once before the component has been used to establish a connection. Enabling FIPS while an instance of the component is active and connected may result in unexpected behavior.
For more details, please see the FIPS 140-2 Compliance article.
Note: This setting is applicable only on Windows.
Note: Enabling FIPS compliance requires a special license; please contact sales@nsoftware.com for details.
Setting this configuration setting to true tells the component to use the internal implementation instead of using the system security libraries.
On Windows, this setting is set to false by default. On Linux/macOS, this setting is set to true by default.
If using the .NET Standard Library, this setting will be true on all platforms. The .NET Standard library does not support using the system security libraries.
Note: This setting is static. The value set is applicable to all components used in the application.
When this value is set, the product's system dynamic link library (DLL) is no longer required as a reference, as all unmanaged code is stored in that file.
Trappable Errors (AESFile Component)
AESFile Errors
105 | An invalid parameter was specified. |
111 | Overwrite is false and the destination already exists. |
112 | No input was specified. |
115 | Invalid password. |
116 | No password was specified. |
202 | The input file is not valid AESF format. |
303 | Cannot open file. |
304 | Cannot write file. |
305 | Cannot read file. |
306 | Cannot create file. |