Class ReadableUserCodeGenerator

Namespace

Fdyay.IdentityServer.Services

Assembly

Fdyay.IdentityServer.Core.dll

Twelve characters from an alphabet without the ones misread off a screen: this server's default.

public sealed class ReadableUserCodeGenerator : IUserCodeGenerator

Inheritance

object

ReadableUserCodeGenerator

Implements

IUserCodeGenerator

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

The alphabet omits characters that are read wrong off a screen and typed wrong into a phone — no O or 0, no I, L or 1, no U against V. A user code is entered by hand from across a room, so an alphabet that is merely large costs more in mistyped codes than it buys in entropy.

Twelve characters from a 20 character alphabet is a little over 51 bits, which matters because the code names a pending authorization to anyone who guesses it. Throttling the polling endpoint is not enough on its own: the user code is entered on a different surface, so it must be hard to guess in its own right. Until 0.83.0 this was NumericUserCodeService, a name it never deserved; NumericUserCodeGenerator is the numeric one.

Properties

RetryLimit

How many codes may be tried for one device before giving up on finding an unused one.

public int RetryLimit { get; }

Property Value

int

Remarks

UserCodeType

The name a client or DeviceFlowOptions.DefaultUserCodeType selects this generator by.

public string UserCodeType { get; }

Property Value

string

Remarks

Readable.

Methods

GenerateAsync(CancellationToken)

A new user code of this generator's type. Whether it is already in use is the caller's to check.

public Task<string> GenerateAsync(CancellationToken cancellationToken = default)

Parameters

cancellationToken CancellationToken

Cancels the generation.

Returns

Task<string>

The code.