Class Helpers

Helper methods to ease interaction with Web API 3. These methods require .NET Framework 4.0 or 4.6.

Inheritance

System.Object

Helpers

Inherited Members

System.Object.ToString()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

Namespace: SKM.V3.Methods

Assembly: Cryptolens.Licensing.dll

Syntax

public static class Helpers

Properties

WindowsOnly

Only set this setting if you plan to target Windows only. It's only necessary in rare cases. If you have any questions, please contact support@cryptolens.io.

Declaration

public static bool WindowsOnly { get; set; }

Property Value

Type	Description
System.Boolean

Methods

ComputePasswordHash(String)

Computes a string hash of a password using PBKDF2. Note, in comparison to using hash algorithms such as SHA256, the algorithm used in this method slows down the computation on purpose, to make sure it is harder to guess the original password.

Declaration

public static string ComputePasswordHash(string password)

Parameters

Type	Name	Description
System.String	password

Returns

Type	Description
System.String

ComputePasswordHash(String, Byte[])

Computes a string hash of a password using PBKDF2. Note, in comparison to using hash algorithms such as SHA256, the algorithm used in this method slows down the computation on purpose, to make sure it is harder to guess the original password.

Declaration

public static string ComputePasswordHash(string password, byte[] salt = null)

Parameters

Type	Name	Description
System.String	password
System.Byte[]	salt

Returns

Type	Description
System.String

GetAssemblyHash()

Computes the method of the entry assembly. This method is intended to be called from an SDK that you want to protect. The "Entry Assembly" is the first assembly that leads to a method being called in your SDK.

Normally, if a customer uses your SDK in an assembly A, this method will compute the hash/fingerprint of that assembly. If they have developed two assemblies, where the A uses B and B uses your SDK (which calls this method), i.e. A -> B -> SDK, then the hash is computed of the first assembly, i.e. A.

Declaration

public static AssemblySignature GetAssemblyHash()

Returns

Type	Description
AssemblySignature	An AssemblySignature or null if the file cannot be found and/or cannot be read.

GetAssemblyHash(String)

Computes the method of the entry assembly. This method is intended to be called from an SDK that you want to protect. The "Entry Assembly" is the first assembly that leads to a method being called in your SDK.

Normally, if a customer uses your SDK in an assembly A, this method will compute the hash/fingerprint of that assembly. If they have developed two assemblies, where the A uses B and B uses your SDK (which calls this method), i.e. A -> B -> SDK, then the hash is computed of the first assembly, i.e. A.

Declaration

public static AssemblySignature GetAssemblyHash(string path)

Parameters

Type	Name	Description
System.String	path	Allows you to specify a custom path of the assembly to sign. If null, the default assembly will be signed, as described in the summary.

Returns

Type	Description
AssemblySignature	An AssemblySignature or null if the file cannot be found and/or cannot be read.

GetFloatingLicenseInformation(ActivateModel, KeyInfoResult)

Returns floating license related information.

Declaration

public static FloatingLicenseInformation GetFloatingLicenseInformation(ActivateModel activationModel, KeyInfoResult activationResult)

Parameters

Type	Name	Description
ActivateModel	activationModel
KeyInfoResult	activationResult

Returns

Type	Description
FloatingLicenseInformation

GetFloatingLicenseInformation(Int32, Int32, Int32)

Returns floating license related information.

Declaration

public static FloatingLicenseInformation GetFloatingLicenseInformation(int MaxOverdraft, int MaxNoOfMachines, int UsedFloatingMachines)

Parameters

Type	Name	Description
System.Int32	MaxOverdraft
System.Int32	MaxNoOfMachines
System.Int32	UsedFloatingMachines

Returns

Type	Description
FloatingLicenseInformation

GetMachineCode(Boolean, Int32)

Returns the machine code of the current device with SHA-256 as the hash function. This method works differently depending on the binaries that you use. By default, machine code is computed using COM, which requires System.Management. This is only supported on Windows, it's better to set platformIndependent=true. If you use a version of library without System.Management, the platform independent machine code will be computed by default.

The supported platforms are Windows, Mac and Linux. Note, sudo access is required if Linux is used.

In newer projects, we recommend to always set platformIndependent=true or use GetMachineCodePI().

If version is set to 2, you can get the machine code as in the Python client, assuming similar settings are used. You can read more about it here: https://help.cryptolens.io/faq/index#machine-code-generation

Declaration

[Obsolete]
public static string GetMachineCode(bool platformIndependent = false, int v = 1)

Parameters

Type	Name	Description
System.Boolean	platformIndependent
System.Int32	v

Returns

Type	Description
System.String

GetMachineCodePI()

Computes a platform independent machine code that works on Windows, Linux and Mac and does not require System.Management.

Note: On Linux, sudo access is necessary.

Declaration

public static string GetMachineCodePI()

Returns

Type	Description
System.String

GetMachineCodePI(Int32)

Computes a platform independent machine code that works on Windows, Linux and Mac and does not require System.Management.

Note: On Linux, sudo access is necessary.

If version is set to 2, you can get the machine code as in the Python client, assuming similar settings are used. You can read more about it here: https://help.cryptolens.io/faq/index#machine-code-generation

Declaration

public static string GetMachineCodePI(int v = 1)

Parameters

Type	Name	Description
System.Int32	v

Returns

Type	Description
System.String

GetOSStats()

Creates a JSON dictionary of the type MachineInfo, which contains OSVersion, OSName and Is64Bit (not available in NET 3.5).

Declaration

public static string GetOSStats()

Returns

Type	Description
System.String	A string representation of the JSON dictionary.

GetPlatform()

Declaration

public static Helpers.OSType GetPlatform()

Returns

Type	Description
Helpers.OSType

HasFeature(LicenseKey, Int32)

Checks so that a certain Feature is enabled (i.e. it's set to TRUE).

Declaration

public static bool HasFeature(LicenseKey licenseKey, int featureNumber)

Parameters

Type	Name	Description
LicenseKey	licenseKey
System.Int32	featureNumber	The feature number, eg. feature1, feature 2, etc. FeatureNumber can be 1,2,...,8.

Returns

Type	Description
System.Boolean	A key information object if the condition is satisfied. Null otherwise.

HasFeature(LicenseKey, String)

Uses a special data object associated with the license key to determine if a certain feature exists (instead of the 8 feature flags).

Formatting: The name of the data object should be 'cryptolens_features' and it should be structured as a JSON array.

For example,

["f1", "f2"]

means f1 and f2 are true. You can also have feature bundling, eg.

["f1", ["f2",["voice","image"]]]

which means that f1 and f2 are true, as well as f2.voice and f2.image. You can set any depth, eg. you can have

["f1", ["f2",[["voice",["all"]], "image"]]]

means f2.voice.all is true as well as f2.voice and f2. The dots symbol is used to specify the "sub-features".

Read more here: https://help.cryptolens.io/web-interface/feature-templates

Declaration

public static bool HasFeature(LicenseKey licenseKey, string featureName)

Parameters

Type	Name	Description
LicenseKey	licenseKey	The license key
System.String	featureName	For example, "f2.voice.all".

Returns

Type	Description
System.Boolean

IsOnRightMachine(LicenseKey, Boolean, Boolean, Boolean)

Checks if the current license key is on the correct device with SHA-256 as the hash function.

Declaration

public static bool IsOnRightMachine(LicenseKey licenseKey, bool isFloatingLicense = false, bool allowOverdraft = false, bool platformIndependent = false)

Parameters

Type	Name	Description
LicenseKey	licenseKey	The license key object.
System.Boolean	isFloatingLicense	If this is a floating license, this parameter has to be set to true. You can enable floating licenses by setting FloatingTimeInterval to a value greater than 0.
System.Boolean	allowOverdraft	If floating licensing is enabled with overdraft, this parameter should be set to true. You can enable overdraft by setting MaxOverdraft to a value greater than 0.
System.Boolean	platformIndependent	Allows you to specify if you want to use the old machine code method that is based on COM and requires System.Management or use the new platform independent method, i.e. GetMachineCodePI().

Returns

Type	Description
System.Boolean

IsOnRightMachine(LicenseKey, String, Boolean, Boolean)

Checks if the current license key is on the correct device with SHA-256 as the hash function.

Declaration

public static bool IsOnRightMachine(LicenseKey licenseKey, string machineCode, bool isFloatingLicense = false, bool allowOverdraft = false)

Parameters

Type	Name	Description
LicenseKey	licenseKey	The license key object.
System.String	machineCode	A unique identifier of the machine.
System.Boolean	isFloatingLicense	If this is a floating license, this parameter has to be set to true. You can enable floating licenses by setting FloatingTimeInterval to a value greater than 0.
System.Boolean	allowOverdraft	If floating licensing is enabled with overdraft, this parameter should be set to true. You can enable overdraft by setting MaxOverdraft to a value greater than 0.

Returns

Type	Description
System.Boolean

IsOnRightMachinePI(LicenseKey, Boolean, Boolean, Int32)

Checks if the current license key is on the correct device with SHA-256 as the hash function.

Declaration

public static bool IsOnRightMachinePI(LicenseKey licenseKey, bool isFloatingLicense = false, bool allowOverdraft = false, int v = 1)

Parameters

Type	Name	Description
LicenseKey	licenseKey	The license key object.
System.Boolean	isFloatingLicense	If this is a floating license, this parameter has to be set to true. You can enable floating licenses by setting FloatingTimeInterval to a value greater than 0.
System.Boolean	allowOverdraft	If floating licensing is enabled with overdraft, this parameter should be set to true. You can enable overdraft by setting MaxOverdraft to a value greater than 0.
System.Int32	v	If version is set to 2, you can get the machine code as in the Python client, assuming similar settings are used. You can read more about it here: https://help.cryptolens.io/faq/index#machine-code-generation

Returns

Type	Description
System.Boolean

IsSuccessful(BasicResult)

Checks if the result obtained from an API call is successful.

Declaration

public static bool IsSuccessful(BasicResult result)

Parameters

Type	Name	Description
BasicResult	result

Returns

Type	Description
System.Boolean

IsVM()

This method can help to detect if the application is running inside a virtual machine. It has been tested in Microsoft Hyper-V. Support for other VM applications is coming soon.

Declaration

public static bool IsVM()

Returns

Type	Description
System.Boolean

VerifyPassword(LicenseKey, String, String)

This method verifies the username and password with the information in the LicenseKey object. It provides a way to activate a license on a per user rather than per machine basis. To compute the password, the ComputePasswordHash(String) is used. A tutorial on how everything can be set up is available here: https://help.cryptolens.io/licensing-models/user-based-activations

Declaration

public static bool VerifyPassword(LicenseKey license, string username, string password)

Parameters

Type	Name	Description
LicenseKey	license
System.String	username
System.String	password

Returns

Type	Description
System.Boolean

VerifySDKLicenseCertificate(String)

Verifies that the certificate of the software using the SDK is valid. This method will use GetAssemblyHash() to compute the hash of the assembly. The entry assembly will be verified, in other words, the assembly that initiated the call first.

Declaration

public static LicenseKey VerifySDKLicenseCertificate(string RSAPubKey)

Parameters

Type	Name	Description
System.String	RSAPubKey	Your RSA Public Key, which can be found here: https://app.cryptolens.io/docs/api/v3/QuickStart

Returns

Type	Description
LicenseKey	License Key object if the certificate is valid and null otherwise.

VerifySDKLicenseCertificate(String, String, String)

Verifies that the certificate of the software using the SDK is valid. This method will use GetAssemblyHash() to compute the hash of the assembly. The entry assembly will be verified, in other words, the assembly that initiated the call first.

Declaration

public static LicenseKey VerifySDKLicenseCertificate(string RSAPubKey, string certificate, string path)

Parameters

Type	Name	Description
System.String	RSAPubKey	Your RSA Public Key, which can be found here: https://app.cryptolens.io/docs/api/v3/QuickStart
System.String	certificate	The name of the certificate. Do not add .skm extension, it will be added automatically.
System.String	path	The path to the certificate and the assembly, whose hash is signed. Note, they need to be in the same folder.

Returns

Type	Description
LicenseKey	License Key object if the certificate is valid and null otherwise.