DPAPI Class
Properties Methods Events Config Settings Errors
The DPAPI class allows you to protect and unprotect data.
Syntax
class ipworksencrypt.DPAPI
Remarks
The class supports the classic Microsoft Windows Data Protection API (DPAPI) or CNG DPAPI implementation. The use of use_cng determines which implementation is used.
The classic DPAPI functionality protects data on a single system. The CNG DPAPI is designed with modern use cases involved. In many cases, especially with cloud computing, protection and unprotection may be done on different systems. With this in mind the Microsoft CNG DPAPI allows encrypting to a set of principals that can be used to unprotect the data on other systems after authenticating.
Protecting Data
protect protects the specified data.
The class supports protecting data using either the classic DPAPI or CNG DPAPI implementation. The use of use_cng determines which implementation is used. The list of applicable properties differs depending on whether CNG DPAPI is being used.
When using classic DPAPI (use_cng is False), the following optional properties are applicable:
When using CNG DPAPI (use_cng is True), the following properties are applicable:
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:
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
Code Example (Classic DPAPI - use_cng is False)
//Protect
Dpapi dpapi = new Dpapi();
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;
//Unprotect
dpapi = new Dpapi();
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
Code Example (CNG DPAPI - use_cng is True)
//Protect
Dpapi dpapi = new Dpapi();
dpapi.UseCNG = true;
dpapi.ProtectionDescriptor = "LOCAL=user";
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;
//Unprotect
dpapi = new Dpapi();
dpapi.UseCNG = true;
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
Unprotecting Data
unprotect unprotects the specified data.
The class supports unprotecting data using either the classic DPAPI or CNG DPAPI implementation. The use of use_cng determines which implementation is used. The list of applicable properties differs depending on whether CNG DPAPI is being used.
When using classic DPAPI (use_cng is False), the following optional properties are applicable:
- data_description (populated after completion)
- password
When using CNG DPAPI (use_cng is True), the following properties are applicable:
- protection_descriptor (populated after completion)
- UseStreamMode
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:
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
Code Example (Classic DPAPI - use_cng is False)
//Protect
Dpapi dpapi = new Dpapi();
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;
//Unprotect
dpapi = new Dpapi();
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
Code Example (CNG DPAPI - use_cng is True)
//Protect
Dpapi dpapi = new Dpapi();
dpapi.UseCNG = true;
dpapi.ProtectionDescriptor = "LOCAL=user";
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;
//Unprotect
dpapi = new Dpapi();
dpapi.UseCNG = true;
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
Property List
The following is the full list of the properties of the class with short descriptions. Click on the links for further details.
data_description | The description of data. |
input_file | The file to process. |
input_message | The message to process. |
output_file | The output file when encrypting or decrypting. |
output_message | The output message after processing. |
overwrite | Indicates whether or not the class should overwrite files. |
password | An optional password to further protect data. |
prompt_title | The title of the prompt window. |
prompt_user | Whether to display a prompt. |
protection_descriptor | The CNG protection descriptor. |
use_cng | Whether to use CNG DPAPI. |
use_hex | Whether input or output is hex encoded. |
Method List
The following is the full list of the methods of the class with short descriptions. Click on the links for further details.
config | Sets or retrieves a configuration setting. |
protect | Protects the data. |
reset | Resets the class. |
unprotect | Unprotects the data. |
Event List
The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.
on_error | Information about errors during data delivery. |
on_progress | Fired as progress is made. |
Config Settings
The following is a list of config settings for the class with short descriptions. Click on the links for further details.
EscapeDescriptor | Whether to escape the protection descriptor. |
ProtectionFlags | Used to specify additional options. |
UseStreamMode | Whether to use the CNG streaming operations. |
BuildInfo | Information about the product's build. |
CodePage | The system code page used for Unicode to Multibyte translations. |
LicenseInfo | Information about the current license. |
ProcessIdleEvents | Whether the class uses its internal event loop to process events when the main thread is idle. |
SelectWaitMillis | The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process. |
UseInternalSecurityAPI | Tells the class whether or not to use the system security libraries or an internal implementation. |
data_description Property
The description of data.
Syntax
def get_data_description() -> str: ... def set_data_description(value: str) -> None: ...
data_description = property(get_data_description, set_data_description)
Default Value
""
Remarks
This property specifies an optional description of the protected data.
This may be set before calling protect. This property will be populated when calling unprotect.
This setting is not applicable when use_cng is set to True.
input_file Property
The file to process.
Syntax
def get_input_file() -> str: ... def set_input_file(value: str) -> None: ...
input_file = property(get_input_file, set_input_file)
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:
- input_file
- input_message
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
input_message Property
The message to process.
Syntax
def get_input_message() -> bytes: ... def set_input_message(value: bytes) -> None: ...
input_message = property(get_input_message, set_input_message)
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:
- input_file
- input_message
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
output_file Property
The output file when encrypting or decrypting.
Syntax
def get_output_file() -> str: ... def set_output_file(value: str) -> None: ...
output_file = property(get_output_file, set_output_file)
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:
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
output_message Property
The output message after processing.
Syntax
def get_output_message() -> bytes: ...
output_message = property(get_output_message, None)
Default Value
""
Remarks
This property will be populated with the output from the operation if output_file is 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:
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
This property is read-only.
overwrite Property
Indicates whether or not the class should overwrite files.
Syntax
def get_overwrite() -> bool: ... def set_overwrite(value: bool) -> None: ...
overwrite = property(get_overwrite, set_overwrite)
Default Value
FALSE
Remarks
This property indicates whether or not the class will overwrite output_file. If overwrite is False, an error will be thrown whenever output_file exists before an operation. The default value is False.
password Property
An optional password to further protect data.
Syntax
def get_password() -> str: ... def set_password(value: str) -> None: ...
password = property(get_password, set_password)
Default Value
""
Remarks
This property may be set to a password to protect the data further.
When protecting data without specifying a password any application running under the same user account can unprotect the data. By specifying a password another piece of information is required to unprotect the data.
This may be set before calling protect. If a password was specified when protecting data it must be set before calling unprotect.
This setting is not applicable when use_cng is set to True.
prompt_title Property
The title of the prompt window.
Syntax
def get_prompt_title() -> str: ... def set_prompt_title(value: str) -> None: ...
prompt_title = property(get_prompt_title, set_prompt_title)
Default Value
""
Remarks
This property specifies the title of the prompt dialog if prompt_user is True. The default value is empty string.
This setting is not applicable when use_cng is set to True.
prompt_user Property
Whether to display a prompt.
Syntax
def get_prompt_user() -> bool: ... def set_prompt_user(value: bool) -> None: ...
prompt_user = property(get_prompt_user, set_prompt_user)
Default Value
FALSE
Remarks
This property specifies whether a prompt is displayed when calling protect. This dialog is created by the system and informs the user of the request action. The user may accept or cancel the request. If the user cancels the request the protect method fails with an error.
When True the prompt_title may be set to customize the window title.
This setting is not applicable when use_cng is set to True. ;
protection_descriptor Property
The CNG protection descriptor.
Syntax
def get_protection_descriptor() -> str: ... def set_protection_descriptor(value: str) -> None: ...
protection_descriptor = property(get_protection_descriptor, set_protection_descriptor)
Default Value
""
Remarks
This property specifies the protection descriptor rule string. The protection descriptor is used by the system to decide which entities can unprotect the data at a later time. This property must be specified before calling protect. This property is populated after calling unprotect.
Protection descriptors can be defined for the following types of authorization:
- A local user or machine
- An account or group in an Active Directory forest
- A set of web credentials
- A certificate in the user's certificate store
A local user or machine may be used for machines that are or are not on a domain. For instance:
- LOCAL=user
- LOCAL=machine
The use of SID and SDDL requires that the machine be part of a domain. For instance:
- SID=S-1-5-21-4392301 AND SID=S-1-5-21-3101812
- SDDL=O:S-1-5-5-0-290724G:SYD:(A;;CCDC;;;S-1-5-5-0-290724)(A;;DC;;;WD)
Certificates may also be used as a descriptor. To decrypt, the certificate with corresponding private key must be present in the user's certificate store. The public certificate can be specified as the SHA1 thumbprint (hash) of the certificate, or the base64 encoded certificate itself. For instance:
- CERTIFICATE=HashID:28ac375635b82ca3e20a1c9422145bc93965dae7
- CERTIFICATE=CertBlob:MIIC7TCCAdWgAw...pgpVgYpppr
The use of AND and OR operators are accepted in order to encrypt data for multiple parties or establish multiple conditions for decryption.
For more details about protection descriptors and accepted formats please refer to the Microsoft Documentation for Protection Descriptors
This setting is only applicable when use_cng is set to True.
use_cng Property
Whether to use CNG DPAPI.
Syntax
def get_use_cng() -> bool: ... def set_use_cng(value: bool) -> None: ...
use_cng = property(get_use_cng, set_use_cng)
Default Value
FALSE
Remarks
The class supports protecting data using either the classic DPAPI or CNG DPAPI implementation. When set to True the CNG DPAPI implementation is sued. When set to False (default) the classic DPAPI implementation is used.
use_hex Property
Whether input or output is hex encoded.
Syntax
def get_use_hex() -> bool: ... def set_use_hex(value: bool) -> None: ...
use_hex = property(get_use_hex, set_use_hex)
Default Value
FALSE
Remarks
This property specifies whether the encrypted data is hex encoded.
If set to True, when protect is called the class will perform the encryption as normal and then hex encode the output. output_message or output_file will hold hex encoded data.
If set to True, when unprotect is called the class will expect input_message or input_file to hold hex encoded data. The class will then hex decode the data and perform decryption as normal.
config Method
Sets or retrieves a configuration setting.
Syntax
def config(configuration_string: str) -> str: ...
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.
protect Method
Protects the data.
Syntax
def protect() -> None: ...
Remarks
protect protects the specified data.
The class supports protecting data using either the classic DPAPI or CNG DPAPI implementation. The use of use_cng determines which implementation is used. The list of applicable properties differs depending on whether CNG DPAPI is being used.
When using classic DPAPI (use_cng is False), the following optional properties are applicable:
When using CNG DPAPI (use_cng is True), the following properties are applicable:
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:
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
Code Example (Classic DPAPI - use_cng is False)
//Protect
Dpapi dpapi = new Dpapi();
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;
//Unprotect
dpapi = new Dpapi();
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
Code Example (CNG DPAPI - use_cng is True)
//Protect
Dpapi dpapi = new Dpapi();
dpapi.UseCNG = true;
dpapi.ProtectionDescriptor = "LOCAL=user";
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;
//Unprotect
dpapi = new Dpapi();
dpapi.UseCNG = true;
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
reset Method
Resets the class.
Syntax
def reset() -> None: ...
Remarks
When called, the class will reset all of its properties to their default values.
unprotect Method
Unprotects the data.
Syntax
def unprotect() -> None: ...
Remarks
unprotect unprotects the specified data.
The class supports unprotecting data using either the classic DPAPI or CNG DPAPI implementation. The use of use_cng determines which implementation is used. The list of applicable properties differs depending on whether CNG DPAPI is being used.
When using classic DPAPI (use_cng is False), the following optional properties are applicable:
- data_description (populated after completion)
- password
When using CNG DPAPI (use_cng is True), the following properties are applicable:
- protection_descriptor (populated after completion)
- UseStreamMode
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:
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
Code Example (Classic DPAPI - use_cng is False)
//Protect
Dpapi dpapi = new Dpapi();
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;
//Unprotect
dpapi = new Dpapi();
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
Code Example (CNG DPAPI - use_cng is True)
//Protect
Dpapi dpapi = new Dpapi();
dpapi.UseCNG = true;
dpapi.ProtectionDescriptor = "LOCAL=user";
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;
//Unprotect
dpapi = new Dpapi();
dpapi.UseCNG = true;
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
on_error Event
Information about errors during data delivery.
Syntax
class DPAPIErrorEventParams(object): @property def error_code() -> int: ... @property def description() -> str: ... # In class DPAPI: @property def on_error() -> Callable[[DPAPIErrorEventParams], None]: ... @on_error.setter def on_error(event_hook: Callable[[DPAPIErrorEventParams], None]) -> None: ...
Remarks
The on_error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.
ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.
on_progress Event
Fired as progress is made.
Syntax
class DPAPIProgressEventParams(object): @property def bytes_processed() -> int: ... @property def percent_processed() -> int: ... # In class DPAPI: @property def on_progress() -> Callable[[DPAPIProgressEventParams], None]: ... @on_progress.setter def on_progress(event_hook: Callable[[DPAPIProgressEventParams], None]) -> None: ...
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.
DPAPI Config Settings
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.DPAPI Config Settings | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
EscapeDescriptor:
Whether to escape the protection descriptor.This setting controls whether the protection_descriptor value is escaped when protect is called. When set to False (default) the value is passed exactly as provided to the underlying system libraries. When set to True the value is first escaped according to the escaping rules defined by Microsoft.
The default value of EscapeDescriptor is True. This setting is only applicable when use_cng is set to True. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
ProtectionFlags:
Used to specify additional options.Additional options are available to restrict or change the behavior of the protect and unprotect operations.
By default no additional settings are specified (the value is 0). You may set this property to the binary 'OR' of one or more of the following values:
This setting is not applicable when use_cng is set to True. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
UseStreamMode:
Whether to use the CNG streaming operations.When set to True the class will use the CNG streaming operations when protect and unprotect are called. When working with large amounts of data this can reduce the memory overhead during processing. Note that when enabled input_file and output_file should be used for optimal memory usage.
The default value of UseStreamMode is False. This setting is only applicable when use_cng is set to True. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Base Config Settings | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
BuildInfo: Information about the product's build.When queried, this setting will return a string containing information about the product's build. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
CodePage:
The system code page used for Unicode to Multibyte translations.The default code page is Unicode UTF-8 (65001).
The following is a list of valid code page identifiers:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
LicenseInfo:
Information about the current license.When queried, this setting will return a string containing information about the license this instance of a class is using. It will return the following information:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
ProcessIdleEvents: Whether the class uses its internal event loop to process events when the main thread is idle.If set to False, the class will not fire internal idle events. Set this to False to use the class in a background thread on Mac OS. By default, this setting is True. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
SelectWaitMillis: The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.If there are no events to process when do_events is called, the class will wait for the amount of time specified here before returning. The default value is 20. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
UseInternalSecurityAPI: Tells the class whether or not to use the system security libraries or an internal implementation. By default the class will use the system security libraries to perform cryptographic functions where applicable. Setting this to True tells the class to use the internal implementation instead of using the system's security API. |
DPAPI Errors
DPAPI Errors
104 Cannot read or write file. | |
109 Cannot protect data. | |
110 Cannot unprotect data | |
111 OutputFile already exists and Overwrite is False. | |
304 Cannot write file. | |
305 Cannot read file. | |
306 Cannot create file. |