OAuth2 Swift Reference Documentation

CkoOAuth2

Current Version: 11.5.0

OAuth2 Authorization Code Flow

Obtain OAuth2 access tokens from desktop and native applications

The Chilkat.OAuth2 class enables desktop and native applications to perform the OAuth 2.0 Authorization Code Flow for obtaining an initial access token. The flow begins with StartAuth, which generates the authorization URL to open in a browser and starts a background listener for the local redirect callback.

Browser-based authorization Use LaunchBrowser to open the generated authorization URL.
Local redirect handling Chilkat listens locally for the provider’s redirect response.
Token exchange The authorization code is exchanged for access and refresh tokens.
Diagnostics and state Inspect AuthFlowState, FailureInfo, and token response data.

After the user grants or denies authorization, Chilkat captures the redirect response, completes the token exchange, and makes the results available through properties such as AccessToken, RefreshToken, AccessTokenResponse, AuthFlowState, and FailureInfo.

The class also supports PKCE, refresh-token requests, custom authorization and token parameters, secure OS-backed secret resolution, and detailed diagnostic information.

Note: This class is primarily used to obtain the initial OAuth2 access token. After that, applications typically use the refresh token to obtain new access tokens for an extended period without requiring further user interaction.

Object Creation

let obj = CkoOAuth2()!

Properties

AccessToken
accessToken: String!
Introduced in version 9.5.0.59

Contains the access_token extracted from the most recent successful token response. It is updated after a successful authorization-code exchange or refresh-token request.

The access token is presented to the protected API, commonly in an HTTP header:

Authorization: Bearer ACCESS_TOKEN
Bearer credential: Anyone possessing a bearer access token can use the authority it grants until the token expires or is revoked. Store it securely, transmit it only over TLS, and never place it in a URL or ordinary log.

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AccessTokenResponse
accessTokenResponse: String! (read-only)
Introduced in version 9.5.0.59

Contains the raw response body returned by the token endpoint after a successful authorization-code exchange or refresh-token request.

Most providers return JSON similar to:

{
  "token_type": "Bearer",
  "expires_in": 3600,
  "access_token": "...",
  "scope": "read write",
  "refresh_token": "..."
}
FieldTypical meaning
access_tokenCredential presented to the protected API.
token_typeUsually Bearer.
expires_inAccess-token lifetime in seconds, when supplied.
scopeScopes actually granted, when supplied.
refresh_tokenCredential used to request later access tokens, when issued.
id_tokenOpenID Connect identity token, when requested and issued.

Some providers return form-encoded text instead of JSON. Use GetAccessTokenResponseSb when a StringBuilder destination is preferred.

Sensitive response: This property can contain live credentials. Do not include it in ordinary logs, exception reports, telemetry, or user-visible diagnostics.

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AppCallbackUrl
appCallbackUrl: String!
Introduced in version 9.5.0.73

Specifies a public HTTPS callback URL on an application-controlled web server when the provider will not redirect directly to localhost or a loopback IP address.

The intermediary endpoint receives the provider's redirect and forwards the complete callback, including code, state, error, and any provider-specific parameters, to the local listener used by Chilkat.

Security responsibility: The intermediary handles a short-lived authorization code and state value. It must use HTTPS, avoid logging sensitive query data, validate and preserve parameters correctly, and prevent use as an open redirect.
Use only when necessary: A direct loopback redirect with PKCE is simpler and avoids introducing a public relay. Prefer it whenever the provider supports native-application loopback redirects.

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AuthFlowState
authFlowState: Int (read-only)
Introduced in version 9.5.0.59

Reports the current state of the background authorization flow.

ValueStateMeaning
0IdleNo authorization flow has been started.
1Waiting for redirectThe local listener is waiting for the browser callback.
2Exchanging codeThe redirect was received and the background thread is waiting for the token-endpoint response.
3SuccessThe flow completed and token response properties are available.
4DeniedThe authorization server returned an access-denied response. Inspect AccessTokenResponse.
5FailedThe flow failed before successful completion. Inspect FailureInfo and LastErrorText.
Polling pattern: After opening the authorization URL, periodically read this property until it is 3, 4, or 5. Avoid a tight loop; sleep briefly or use the host environment's timer mechanism.

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AuthorizationEndpoint
authorizationEndpoint: String!
Introduced in version 9.5.0.59

Specifies the authorization endpoint to which the user's browser is directed. StartAuth appends the client identifier, redirect URI, scope, state, PKCE values, and other configured authorization parameters.

ProviderAuthorization endpointToken endpoint
Googlehttps://accounts.google.com/o/oauth2/v2/authhttps://oauth2.googleapis.com/token
Microsoft identity platformhttps://login.microsoftonline.com/{tenant}/oauth2/v2.0/authorizehttps://login.microsoftonline.com/{tenant}/oauth2/v2.0/token
Salesforce productionhttps://login.salesforce.com/services/oauth2/authorizehttps://login.salesforce.com/services/oauth2/token
QuickBooks Onlinehttps://appcenter.intuit.com/connect/oauth2https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer
X APIhttps://x.com/i/oauth2/authorizehttps://api.x.com/2/oauth2/token
Prefer provider metadata: When the provider publishes OAuth authorization-server metadata or OpenID Connect discovery metadata, use its current authorization_endpoint value rather than copying an endpoint from an old example.
Environment and tenant matter: Sandbox, production, regional, and tenant-specific deployments can use different endpoints. The authorization and token endpoints must belong to the same provider environment.

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ClientId
clientId: String!
Introduced in version 9.5.0.59

Specifies the client identifier assigned when the application is registered with the authorization server. It identifies the application in authorization and token requests.

Not a password: A client ID is normally public and may appear in authorization URLs. Its security role is identification, not authentication.

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ClientSecret
clientSecret: String!
Introduced in version 9.5.0.59

Specifies the client secret assigned to a confidential client by the authorization server. It is used when the provider requires the client to authenticate at the token endpoint.

Protect this value: A client secret is a credential. Do not place it in source control, logs, browser URLs, or distributable desktop/mobile binaries. Native applications are public clients and generally cannot keep a shared secret confidential; use PKCE and follow the provider's registration requirements.
PKCE is separate: PKCE protects the authorization code. It does not transform an embedded secret into a confidential credential and does not replace client authentication for a provider that requires it.

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CodeChallenge
codeChallenge: Bool
Introduced in version 9.5.0.59

Set to true to enable Proof Key for Code Exchange (PKCE) for the authorization-code flow. The default is false.

When enabled, Chilkat generates a high-entropy code verifier, sends its transformed challenge in the authorization request, and sends the original verifier during the token exchange.

Recommended for native applications: PKCE binds the authorization code to the application instance that initiated the flow, reducing the risk that an intercepted code can be redeemed by another client. Current OAuth security guidance requires PKCE for public clients and recommends it broadly.

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CodeChallengeMethod
codeChallengeMethod: String!
Introduced in version 9.5.0.59

Selects the PKCE transformation used when CodeChallenge is true.

ValueBehavior
S256Sends a Base64URL-encoded SHA-256 digest of the code verifier. This is the default and recommended method.
plainSends the code verifier itself as the challenge. Use only for compatibility with a provider that cannot support S256.
Avoid downgrading: If a provider rejects S256, do not automatically retry with plain unless the provider is known and explicitly requires it.

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DebugLogFilePath
debugLogFilePath: String!

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

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EnableSecrets
enableSecrets: Bool
Introduced in version 11.5.0

Controls automatic resolution of selected values from operating-system secure storage. The default is false.

When true, the following properties may contain a secret specification beginning with !! instead of a literal value:

The specification has the form:

!![appName|]service[|domain]|username

Chilkat resolves the value through Windows Credential Manager on Windows or Apple Keychain on macOS.

Purpose: Secret specifications allow deployment-specific values to remain outside source code and configuration files. Although endpoints and client IDs are not normally secret, resolving them the same way can centralize application configuration.
Platform availability: This feature depends on supported operating-system credential storage. Ensure the named credential exists and that the process identity has permission to read it.

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FailureInfo
failureInfo: String! (read-only)
Introduced in version 9.5.0.59

Contains diagnostic information when AuthFlowState is 5. The value is cleared when StartAuth begins a new flow.

Use this property for failures in the listener, redirect processing, network connection, or token exchange. Provider-declared authorization denial is represented by state 4 and is normally available in AccessTokenResponse.

Review before logging: Diagnostics can include URLs, response bodies, or request details. Remove authorization codes, tokens, client credentials, and personal information before storing or transmitting logs.

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IncludeNonce
includeNonce: Bool
Introduced in version 9.5.0.78

Set to true to include an OpenID Connect nonce parameter in the authorization request. The nonce is generated by Chilkat using the byte length specified by NonceLength. The default is false.

In OpenID Connect, the authorization server includes the nonce in the ID token so the client can associate that token with the authorization request and detect replay or token-substitution problems.

Nonce versus state: nonce protects the relationship between an OpenID Connect request and its ID token. OAuth state correlates the browser callback with the initiating request and is used for CSRF protection. They are related security controls but are not interchangeable.

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LastErrorHtml
lastErrorHtml: String! (read-only)

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
lastErrorText: String! (read-only)

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
lastErrorXml: String! (read-only)

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
lastMethodSuccess: Bool

Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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ListenPort
listenPort: Int
Introduced in version 9.5.0.59

Specifies the local TCP port on which Chilkat listens for the browser's OAuth redirect. Choose an available nonprivileged port, typically between 1024 and 65535.

The redirect URI registered with the provider must match the host, selected port, and terminating slash generated by this object. For example:

http://127.0.0.1:3017/
  • Use http for a loopback redirect handled entirely on the local computer.
  • Use LocalHost to select localhost or 127.0.0.1.
  • Include the final / when registering the redirect URI.
Provider registration must match: Authorization servers differ in their support for loopback ports and redirect-URI matching. Register the exact form required by the provider. The IPv4 loopback literal 127.0.0.1 is generally more predictable than resolving localhost.

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ListenPortRangeEnd
listenPortRangeEnd: Int
Introduced in version 9.5.0.69

Defines the inclusive end of a local-listener port range that begins with ListenPort. The default value of 0 disables range selection and uses only ListenPort.

When nonzero, Chilkat selects an available port in the inclusive range. For example, ListenPort=55110 and ListenPortRangeEnd=55117 permit ports 55110 through 55117.

Redirect registration: The provider must accept the selected redirect URI. If it requires every exact port to be pre-registered, register each port in the range. If the provider supports the native-app loopback convention with a variable port, follow its documented registration form.

Read ListenPortSelected to determine which port was used.

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ListenPortSelected
listenPortSelected: Int (read-only)
Introduced in version 9.5.0.94

Returns the local port selected for the current or most recently completed authorization flow.

When a range is configured with ListenPortRangeEnd, use this value to determine the actual loopback redirect port. It is also available for the {listenPort} substitution supported by StateParam.

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LocalHost
localHost: String!
Introduced in version 9.5.0.59

Selects the host name used in the loopback redirect URI:

ValueRedirect form
localhosthttp://localhost:{port}/
127.0.0.1http://127.0.0.1:{port}/

The default is localhost. The value must match the redirect URI registered with the provider.

Loopback recommendation: 127.0.0.1 avoids DNS and hosts-file ambiguity and is generally preferable when the provider accepts an IPv4 loopback-literal redirect.

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NonceLength
nonceLength: Int
Introduced in version 9.5.0.80

Specifies the number of random bytes used to generate the hexadecimal OpenID Connect nonce when IncludeNonce is true. The resulting string contains two hexadecimal characters per byte.

The default is 4 bytes, which produces an 8-character hexadecimal nonce.

Entropy matters: For security-sensitive OpenID Connect use, consider a substantially larger nonce, such as 16 bytes or more, unless the provider imposes a different requirement.

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Oob
oob: Bool
Introduced in version 10.0.2

Set to true to use the legacy out-of-band redirect URI urn:ietf:wg:oauth:2.0:oob. The application must obtain the displayed authorization code and pass it to ExchangeCodeForToken. The default is false.

Legacy and often unsupported: OOB authorization exposes a code for manual copy/paste and is no longer accepted by many providers. For desktop applications, use a loopback redirect with PKCE whenever possible.

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RedirectAllowHtml
redirectAllowHtml: String!
Introduced in version 9.5.0.59

Gets or sets the HTML response sent by Chilkat's local listener to the browser after authorization is granted and the redirect is accepted.

The default HTML immediately redirects the browser to Chilkat's confirmation page:

<html>
  <head><meta http-equiv='refresh'
    content='0;url=https://www.chilkatsoft.com/oauth2_allowed.html'></head>
  <body>Thank you for allowing access.</body>
</html>

Replace this value to display application-specific instructions or redirect to a page operated by your organization.

Do not expose credentials: The HTML is shown in a browser. Do not insert the authorization code, access token, refresh token, client secret, or raw callback URL into this page.

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RedirectDenyHtml
redirectDenyHtml: String!
Introduced in version 9.5.0.59

Gets or sets the HTML response sent by Chilkat's local listener to the browser when the authorization server reports that access was denied.

The default HTML immediately redirects the browser to Chilkat's denial page:

<html>
  <head><meta http-equiv='refresh'
    content='0;url=https://www.chilkatsoft.com/oauth2_denied.html'></head>
  <body>The app will not have access.</body>
</html>

Replace this value to display application-specific instructions or redirect to a page operated by your organization.

Denial is not a transport failure: User denial is represented by AuthFlowState value 4. It should normally be handled as a completed flow in which consent was not granted.

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RedirectReqReceived
redirectReqReceived: String! (read-only)
Introduced in version 9.5.0.92

Contains the raw HTTP request received from the browser by Chilkat's local redirect listener. It is intended for troubleshooting callback and provider-parameter problems.

GET /?state=...&code=... HTTP/1.1
Host: 127.0.0.1:3017
User-Agent: ...
Accept: text/html,...

The value can include the request target, query or form parameters, and browser-supplied headers.

Highly sensitive diagnostic data: The request can contain an authorization code, state value, provider identifiers, and browser metadata. Do not record it in production logs without careful redaction.

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RefreshToken
refreshToken: String!
Introduced in version 9.5.0.59

Gets or sets the refresh token used to obtain new access tokens. Chilkat populates this property when the token endpoint issues a refresh_token, and RefreshAccessToken reads it when creating a refresh request.

A provider may omit the refresh token unless an offline-access scope or provider-specific authorization parameter was requested. A refresh response may also return a replacement token.

Long-lived credential: Refresh tokens commonly outlive access tokens and can be used without user interaction. Protect them at least as carefully as passwords, persist replacements after rotation, and delete them when authorization is revoked.

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Resource
resource: String!
Introduced in version 9.5.0.67

Specifies an optional provider-defined resource parameter identifying the API or audience for which a token is requested.

This is used by some OAuth deployments, including older Microsoft identity endpoints and certain Dynamics configurations. Modern Microsoft v2 endpoints generally identify the target API through scope values instead.

Not a universal OAuth parameter: Set this property only when the authorization server documents a required resource value. Do not assume that an API base URL is always the correct value.

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ResponseMode
responseMode: String!
Introduced in version 9.5.0.78

Specifies the response mode requested from an OpenID Connect or provider-specific authorization endpoint.

Set to form_post to add response_mode=form_post, causing the authorization server to return parameters in an auto-submitted HTML form that sends an HTTP POST to the redirect URI. The default is an empty string, which omits the parameter and lets the provider choose its normal mode.

Provider support required: Use only a response mode supported by the provider and compatible with Chilkat's local listener or intermediary callback.

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ResponseType
responseType: String!
Introduced in version 9.5.0.78

Specifies the authorization response type. The default is code, which requests an authorization code.

Set to id_token+code when a provider requires the OpenID Connect hybrid response response_type=id_token code; the plus sign is the URL-encoded representation of a SPACE in the query string.

Prefer the code flow unless required otherwise: Hybrid responses add an ID token to the browser-facing authorization response and require correct OpenID Connect validation, including issuer, audience, signature, expiration, and nonce checks.

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Scope
scope: String!
Introduced in version 9.5.0.59

Specifies the access scopes requested from the authorization server. A scope is a provider-defined permission or capability associated with the resulting access token.

OAuth scope values are commonly separated by a single SPACE character:

openid email profile https://www.googleapis.com/auth/drive.readonly
  • openid requests OpenID Connect processing and an ID token when used with an appropriate response type.
  • email and profile request standard OpenID Connect claims.
  • The Google Drive URI requests read-only access to Drive files.
Provider-defined and consented: Scope names, separators, defaults, and offline-access requirements vary by provider. Request the minimum permissions needed and verify the granted scope returned in the token response.

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StateParam
stateParam: String!
Introduced in version 9.5.0.94

Allows the application to supply an explicit OAuth state value. Normally this property should remain empty so Chilkat generates a cryptographically random state value and validates the returned value automatically.

The automatically generated state is intentionally not exposed through this property.

The special token {listenPort} may appear in an explicitly supplied value. Chilkat replaces it with the actual listener port selected for the flow.

Do not weaken state: State correlates the redirect with the initiating browser flow and helps prevent CSRF and authorization-response injection. If supplying your own value, make it unpredictable, unique per flow, and free of secrets or sensitive application data.

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TokenEndpoint
tokenEndpoint: String!
Introduced in version 9.5.0.59

Specifies the provider's token endpoint. Chilkat sends authorization-code and refresh-token requests to this URL over TLS.

ProviderAuthorization endpointToken endpoint
Googlehttps://accounts.google.com/o/oauth2/v2/authhttps://oauth2.googleapis.com/token
Microsoft identity platformhttps://login.microsoftonline.com/{tenant}/oauth2/v2.0/authorizehttps://login.microsoftonline.com/{tenant}/oauth2/v2.0/token
Salesforce productionhttps://login.salesforce.com/services/oauth2/authorizehttps://login.salesforce.com/services/oauth2/token
QuickBooks Onlinehttps://appcenter.intuit.com/connect/oauth2https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer
X APIhttps://x.com/i/oauth2/authorizehttps://api.x.com/2/oauth2/token
Back-channel endpoint: Unlike the authorization endpoint, the token endpoint is contacted directly by the application, not opened in the user's browser.
Use the provider's current HTTPS endpoint: Endpoint locations can change. Prefer the value published in the provider's OAuth or OpenID Connect metadata, and do not mix sandbox and production endpoints.

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TokenType
tokenType: String!
Introduced in version 9.5.0.59

Contains the token_type value from the most recent successful token response. The common value is Bearer.

Use the returned type: OAuth does not require every token to use the same presentation mechanism. Follow the authorization server's documentation and the returned token type when constructing API requests.

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UncommonOptions
uncommonOptions: String!
Introduced in version 9.5.0.85

Provides a comma-separated list of specialized compatibility options. The default is an empty string and is appropriate for normal OAuth providers.

KeywordEffect
NO_OAUTH2_SCOPEOmits the scope parameter from the authorization-code token request.
ExchangeCodeForTokenUsingJsonSends the authorization-code token request as an HTTP POST with a JSON body instead of the normal form/query representation.
RefreshTokenUsingJsonSends the refresh-token request as an HTTP POST with a JSON body.
Leave empty unless required: These options alter interoperability behavior outside the normal OAuth token-request format. Enable one only when the provider's documentation or Chilkat support explicitly requires it.

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UseBasicAuth
useBasicAuth: Bool
Introduced in version 9.5.0.73

Controls how ClientId and ClientSecret are supplied during the authorization-code token exchange.

ValueBehavior
trueSends HTTP Basic authentication using the client ID as the username and the client secret as the password.
falseSends the client ID and client secret as request parameters. This is the default.
Match the provider's client-authentication method: Some authorization servers require HTTP Basic authentication; others require parameters or no client secret for public clients. A wrong choice usually produces an invalid_client response.
TLS is mandatory: Both forms expose the secret to the token endpoint. They differ in HTTP representation, not in the need for a secure TLS connection.

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VerboseLogging
verboseLogging: Bool

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
version: String! (read-only)

Version of the component/library, such as "10.1.0"

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Methods

AddAuthQueryParam
addAuthQueryParam(name: String, value: String) -> Bool
Introduced in version 9.5.0.85

Adds a name/value query parameter to the authorization URL produced by StartAuth. Call the method multiple times to add multiple provider-specific authorization parameters.

Typical examples include provider extensions such as access_type=offline, prompt=consent, or an account-selection hint.

Do not add secrets: Authorization parameters are placed in a URL and can appear in browser history, proxy logs, and diagnostics. Never put a client secret, access token, refresh token, or other credential in an authorization query parameter.

Returns true for success, false for failure.

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AddRefreshQueryParam
addRefreshQueryParam(name: String, value: String) -> Bool
Introduced in version 9.5.0.97

Adds a provider-specific name/value parameter to requests sent by RefreshAccessToken. Call the method multiple times to add multiple parameters.

Use only when documented: Chilkat automatically supplies the standard refresh-token grant parameters. Additional parameters are provider extensions and should be added only when required by the authorization server.

Returns true for success, false for failure.

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AddTokenQueryParam
addTokenQueryParam(name: String, value: String) -> Bool
Introduced in version 9.5.0.85

Adds a provider-specific name/value parameter to the authorization-code token request that Chilkat sends after receiving the browser redirect. Call the method multiple times to add multiple parameters.

This setting affects the code-for-token exchange performed by StartAuth or ExchangeCodeForToken; it does not alter the browser authorization URL or refresh-token requests.

Nonstandard extension: The normal authorization-code request parameters are generated automatically. Use this method only for an additional parameter documented by the provider, and do not duplicate standard parameters such as grant_type, code, or redirect_uri unless instructed by Chilkat support.

Returns true for success, false for failure.

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Cancel
cancel() -> Bool
Introduced in version 9.5.0.59

Requests cancellation of the authorization flow currently running in the background thread.

Returns true if the cancellation request is accepted. After cancellation, inspect AuthFlowState and FailureInfo to determine the final state.

Scope of cancellation: This stops the local authorization operation. It does not revoke an access token, refresh token, authorization grant, or consent that the provider has already issued.

Returns true for success, false for failure.

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ExchangeCodeForToken
exchangeCode(forToken: String) -> Bool
Introduced in version 10.0.2

Exchanges the authorization code in forToken for tokens at TokenEndpoint.

This is used when the application obtains the authorization code outside Chilkat's local-listener workflow, most commonly with the legacy out-of-band mode selected by Oob. Configure the same client, endpoint, redirect, PKCE, and token-request settings that the provider requires for the original authorization request.

On success, the token properties and AccessTokenResponse are populated in the same manner as a successful background exchange.

Legacy OOB flow: Many major providers no longer accept urn:ietf:wg:oauth:2.0:oob. Prefer an authorization-code flow with a loopback redirect and PKCE whenever the provider supports it.

Returns true for success, false for failure.

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ExchangeCodeForTokenAsync (1)
exchangeCode(forTokenAsync: String) -> CkoTask
Introduced in version 10.0.2

Creates an asynchronous task to call the ExchangeCodeForToken method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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GetAccessTokenResponseSb
getAccessTokenResponseSb(sb: CkoStringBuilder) -> Bool
Introduced in version 10.1.0

Copies the raw token-endpoint response into and returns true on success.

This is the StringBuilder equivalent of reading AccessTokenResponse. The response is commonly JSON, but some providers return form-encoded or other text; this method does not guarantee JSON.

Contains credentials: The response can contain an access token and refresh token. Treat the destination StringBuilder as sensitive data and avoid logging or exposing its contents.

Returns true for success, false for failure.

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GetRedirectRequestParam
getRedirectRequestParam(paramName: String) -> String
Introduced in version 9.5.0.69

Returns the decoded value of from the authorization redirect received by Chilkat's local listener.

Call this after the redirect has been received. It is useful for provider-specific parameters in addition to the standard code, state, and error values. For example, QuickBooks can return a company identifier named realmId:

http://localhost:55568/?state=...&code=...&realmId=1234567890
Provider extensions: OAuth defines the core redirect parameters, but providers may add their own values. Consult the provider's documentation before depending on an additional parameter.
Sensitive redirect data: Authorization codes and related callback parameters are credentials or security-sensitive correlation values. Avoid writing them to ordinary application logs.

Returns nil on failure

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LaunchBrowser
launchBrowser(url: String) -> Bool
Introduced in version 10.1.2

Asks the operating system to open in the user's default web browser. On Windows, macOS, and supported Linux desktop environments, an existing browser may open the URL in a new tab.

This method is typically called with the authorization URL returned by StartAuth. Returns false if the operating system cannot launch a browser or open the URL.

No browser automation: This method only opens the URL. Chilkat does not control the browser, enter credentials, approve consent, or close the browser window.

Returns true for success, false for failure.

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LoadTaskCaller
loadTaskCaller(task: CkoTask) -> Bool
Introduced in version 9.5.0.80

Loads state from so this object can act as the caller associated with a Chilkat asynchronous task.

Returns true for success, false for failure.

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RefreshAccessToken
refreshAccessToken() -> Bool
Introduced in version 9.5.0.59

Sends a refresh-token grant request to TokenEndpoint to obtain a new access token without repeating interactive browser authorization.

Configure ClientId, RefreshToken, and TokenEndpoint, together with whatever client authentication the provider requires. This may include ClientSecret and UseBasicAuth.

On success, Chilkat updates AccessToken, TokenType, and AccessTokenResponse. If the provider rotates refresh tokens and returns a new refresh_token, RefreshToken is also updated.

Persist rotated refresh tokens: Some providers invalidate the old refresh token as soon as a new one is issued. After a successful refresh, securely persist the current value of RefreshToken rather than assuming the previous value remains usable.
Provider-specific requests: Use SetRefreshHeader and AddRefreshQueryParam only when the provider documents additional headers or parameters.

Returns true for success, false for failure.

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RefreshAccessTokenAsync (1)
refreshAccessTokenAsync() -> CkoTask
Introduced in version 9.5.0.59

Creates an asynchronous task to call the RefreshAccessToken method with the arguments provided.

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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SetRefreshHeader
setRefreshHeader(name: String, value: String) -> Bool
Introduced in version 9.5.0.77

Adds or replaces an HTTP request header used by subsequent calls to RefreshAccessToken. is the header field name and value is its value.

Call this method once for each required header. Passing an empty value removes the named header.

Accept: application/json
Normally unnecessary: Standard OAuth refresh requests do not require application-defined headers beyond those generated by the client. Add headers only when the authorization server explicitly requires them, and never place access tokens, refresh tokens, or client secrets in diagnostic headers.

Returns true for success, false for failure.

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SleepMs
sleepMs(millisec: Int)
Introduced in version 9.5.0.59

Suspends the calling thread for milliseconds.

This convenience method is commonly used in a polling loop that checks AuthFlowState while the authorization flow continues on Chilkat's background thread.

Thread behavior: The calling thread is blocked for the requested interval. In a graphical application, use the platform's normal asynchronous or timer mechanism when blocking the UI thread would make the application unresponsive.
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StartAuth
startAuth() -> String
Introduced in version 9.5.0.59

Starts an OAuth 2.0 Authorization Code flow and returns the authorization URL that the application should open in the user's browser.

Before calling this method, configure ClientId, AuthorizationEndpoint, TokenEndpoint, the requested Scope, and the redirect-listener settings such as ListenPort. Configure ClientSecret only when the provider requires client authentication for this application type.

  1. Chilkat constructs and returns the provider's authorization URL.
  2. Chilkat starts a background thread that listens for the redirect request, validates the returned state, and exchanges the authorization code at the token endpoint.

Open the returned URL with LaunchBrowser or another browser-launch mechanism. Poll AuthFlowState until the flow reaches a terminal state.

PKCE and client authentication: Enabling CodeChallenge protects the authorization code from interception and is strongly recommended for desktop and other native applications. PKCE does not make a client secret confidential and does not replace client authentication when the provider requires it for a confidential client.
Failure detection: String-returning bindings return an empty or null-equivalent value on failure. Check the normal method-success indicator and inspect LastErrorText before attempting to open the returned URL.

Returns nil on failure

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UseConnection
useConnection(sock: CkoSocket) -> Bool
Introduced in version 9.5.0.59

Associates with this object for HTTP connections to the token endpoint. This method is optional.

  • Pass an unconnected Socket when it is configured with HTTP-proxy, SOCKS-proxy, local-bind, or other connection options that Chilkat should use when opening the token-endpoint connection.
  • Pass an already connected socket when traffic must travel through an established SSH tunnel or another prebuilt connection.

Without this method, Chilkat opens a direct TLS connection to the token endpoint.

Browser traffic is separate: This socket controls Chilkat's back-channel token requests. It does not configure the user's browser, the provider's authorization page, or the browser's redirect to the local listener.

Returns true for success, false for failure.

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Events

To implement an event callback, your application would define and implement a class that inherits from CkoBaseProgress. Your application can implement methods to override some or all of the default/empty method implementations of the CkoBaseProgress base class.

For example:

class MyOAuth2Progress : CkoBaseProgress {

    override func ProgressInfo(name: String!, value: String!) {
        // application code goes here...
        print(name + ": " + value)
    }

    override func AbortCheck(abort: UnsafeMutablePointer) {
        // application code goes here...
        // To abort the operation, set this equal to true instead of false.
        abort.memory = false
    }

    override func PercentDone(pctDone: NSNumber!, abort: UnsafeMutablePointer) {
        // application code goes here...
        print(pctDone)
        // To abort the operation, set this equal to true instead of false.
        abort.memory = false
    }

    // For asynchronous method calls.
    override func TaskCompleted(task: CkoTask!) {
        // application code goes here...
    }
}

func someAppFunction() {

    // Demonstrate how to set the event callback object...
    let oauth = CkoOAuth2()
    let myOAuthProgress = MyOAuth2Progress()
    
    oauth.setEventCallbackObject(myOAuthProgress)

    // ...
    // ...
    // ...
}

AbortCheck
abortCheck(abort: Bool)

Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second.

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PercentDone
percentDone(pctDone: Int, abort: Bool)

This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).

The PercentDone callback also acts as an AbortCheck event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.

To abort the operation, set the abort output argument to true. This will cause the method to terminate and return a failure status or corresponding failure value.

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ProgressInfo
progressInfo(name: String, value: String)

This event callback provides tag name/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.

Note: Some Chilkat methods don't fire any ProgressInfo events.

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TaskCompleted
taskCompleted(task: CkoTask)

Called from the background thread when an asynchronous task completes.

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