AuthGoogle Zig Reference Documentation

AuthGoogle

Current Version: 11.6.1

Chilkat.AuthGoogle

Obtain Google OAuth 2.0 access tokens using a service account.

Chilkat.AuthGoogle obtains OAuth 2.0 access tokens for Google Cloud Platform APIs and Google Apps APIs using a Google service account. It supports JSON private keys and P12 private keys, OAuth scopes, optional delegated user access, custom JWT claims, access-token validity tracking, token lifetime settings, and integration with Chilkat request classes that need a Google bearer token.

Service account auth

Authenticate server-to-server using a Google service account rather than an interactive browser-based user consent flow.

JSON or P12 keys

Load service account credentials from modern JSON private keys or from legacy P12 private key files.

Scopes and claims

Specify the OAuth scopes required by the target Google API and add custom JWT claims when needed.

Delegated user access

Use domain-wide delegation by setting a subject email when the service account is authorized to act on behalf of a Google Workspace user.

Access-token tracking

Inspect the generated access token, expiration time, remaining lifetime, and validity state before using or refreshing credentials.

Chilkat API integration

Pass the resulting bearer token to Chilkat HTTP, REST, storage, mail, or other Google API request workflows.

Common pattern: Load the service account JSON key or P12 key, set the service account email, required Scope, optional delegated SubEmailAddress, and token lifetime, then call ObtainAccessToken. Use AuthGoogle for service-account OAuth flows; use Chilkat.OAuth2 when the application needs an interactive three-legged OAuth flow involving a user's browser consent.

Object Creation

// Add the package once:
//     zig fetch --save https://chilkatdownload.com/11.6.1/chilkat-zig-11.6.1.tar.gz
// and in build.zig:
//     const chilkat = b.dependency("chilkat", .{ .target = target, .optimize = optimize });
//     exe.root_module.addImport("chilkat", chilkat.module("chilkat"));
const chilkat = @import("chilkat");

// Once per process, before any other Chilkat call:
try chilkat.unlockBundle("Anything for 30-day trial");

const auth_google = try chilkat.AuthGoogle.init();
defer auth_google.deinit();
pub fn init() Allocator.Error!AuthGoogle

Creates the underlying native Chilkat object. AuthGoogle is a one-pointer struct passed by value; copying it copies the handle (two names for one object). Returns error.OutOfMemory if the library could not allocate the object. Use an object from one thread at a time; it may be handed from one thread to another.

pub fn deinit(self: AuthGoogle) void

Releases the native object. Call it exactly once per object (usually with defer); the handle is invalid afterwards. Objects returned by methods are owned by the caller too and are released the same way.

pub fn fromHandle(h: *chilkat.c.CkAuthGoogle.HCkAuthGoogle) AuthGoogle

Wraps a handle obtained from the C API (chilkat.c.CkAuthGoogle), taking ownership of it. The struct's handle field goes the other way, for anything the Zig API does not cover.

Errors and memory

Methods that can fail return an error union: a method whose only outcome is success or failure returns Error!void; a method producing a string returns (Error || Allocator.Error)![:0]u8; a method producing an object returns Error!T. chilkat.Error is error{ChilkatFailed}; the reason for a failure is in getLastErrorText, and the object remains usable. Properties never fail, and methods that answer a question (hasMember, isUnlocked, ...) return a plain bool.

String arguments are [:0]const u8 (UTF-8; string literals can be passed as is). String results are copies allocated with the allocator argument and owned by the caller, so they stay valid across later calls on the same object.

const text = auth_google.someMethod(allocator, ...) catch |err| {
    const why = try auth_google.getLastErrorText(allocator);
    defer allocator.free(why);
    std.debug.print("{s}\n", .{why});
    return err;
};
defer allocator.free(text);

Properties

AccessToken
// read/write
pub fn getAccessToken(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8
pub fn setAccessToken(self: AuthGoogle, value: [:0]const u8) void
Introduced in version 9.5.0.58

The access token to be used in Google API requests. This property is set on a successful call to ObtainAccessToken.

Important: This class is used for authenticating calls to the Google Cloud Platform API and Google Apps API using a service account.. For 3-legged OAuth2, where a browser must be used to interactively get permission from the Google account owner, use the Chilkat OAuth2 class/object.

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DebugLogFilePath
// read/write
pub fn getDebugLogFilePath(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8
pub fn setDebugLogFilePath(self: AuthGoogle, value: [:0]const u8) void

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.

More Information and Examples
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EmailAddress
// read/write
pub fn getEmailAddress(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8
pub fn setEmailAddress(self: AuthGoogle, value: [:0]const u8) void
Introduced in version 9.5.0.58

The client email address of the service account. If a JSON key is used, then the client_email should already be specified within the JSON key, and this property is unused. This property must be set if using a P12 key.

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ExpireNumSeconds
// read/write
pub fn getExpireNumSeconds(self: AuthGoogle) i32
pub fn setExpireNumSeconds(self: AuthGoogle, value: i32) void
Introduced in version 9.5.0.58

The expiration time, in seconds, of the access token to be requested. The maximum value is 1 hour (3600 seconds). The default value is 3600.

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Iat
// read/write
pub fn getIat(self: AuthGoogle) i32
pub fn setIat(self: AuthGoogle, value: i32) void
Introduced in version 9.5.0.77

This property can be set to override the default current date/time value for the iat claim of the JWT. It can be set to a value indicating the number of seconds from 1970-01-01T00:00:00Z UTC.

The default value is 0, which indicates to use the iat value for the current system date/time. Unless explicitly needed, always leave this property at the default value.

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JsonKey
// read/write
pub fn getJsonKey(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8
pub fn setJsonKey(self: AuthGoogle, value: [:0]const u8) void
Introduced in version 9.5.0.58

The JSON key for obtaining an access token. An application must set either the P12 or JSON private key, but not both.

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LastErrorHtml
// read-only
pub fn getLastErrorHtml(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8

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
// read-only
pub fn getLastErrorText(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8

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
// read-only
pub fn getLastErrorXml(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8

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
// read/write
pub fn getLastMethodSuccess(self: AuthGoogle) bool
pub fn setLastMethodSuccess(self: AuthGoogle, value: bool) void

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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NumSecondsRemaining
// read-only
pub fn getNumSecondsRemaining(self: AuthGoogle) i32
Introduced in version 9.5.0.58

If the access token is valid, contains the number of seconds remaining until it expires. A value of 0 indicates an invalid or expired access token.

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Scope
// read/write
pub fn getScope(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8
pub fn setScope(self: AuthGoogle, value: [:0]const u8) void
Introduced in version 9.5.0.58

A space-delimited list of the permissions that the application requests.

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SubEmailAddress
// read/write
pub fn getSubEmailAddress(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8
pub fn setSubEmailAddress(self: AuthGoogle, value: [:0]const u8) void
Introduced in version 9.5.0.58

The email address of the user for which the application is requesting delegated access.

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Valid
// read-only
pub fn getValid(self: AuthGoogle) bool
Introduced in version 9.5.0.58

true if the AccessToken property contains a valid non-expired access token obtained via the call to ObtainAccessToken.

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VerboseLogging
// read/write
pub fn getVerboseLogging(self: AuthGoogle) bool
pub fn setVerboseLogging(self: AuthGoogle, value: bool) void

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
// read-only
pub fn getVersion(self: AuthGoogle, allocator: Allocator) Allocator.Error![:0]u8

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

More Information and Examples
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Methods

AddClaims
pub fn addClaims(self: AuthGoogle, json: chilkat.JsonObject) Error!void
Introduced in version 9.5.0.99

Adds additional custom claims to the JWT claims set.

Returns error.ChilkatFailed on failure; getLastErrorText explains why.

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GetP12
pub fn getP12(self: AuthGoogle) Error!chilkat.Pfx
Introduced in version 9.5.0.58

Returns the private key in a PFX (P12) object. This is only possible if the private key was previously set by calling SetP12.

Returns error.ChilkatFailed on failure; getLastErrorText explains why. The returned object is owned by the caller: release it with deinit.

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ObtainAccessToken
pub fn obtainAccessToken(self: AuthGoogle, connection: chilkat.Socket) Error!void
Introduced in version 9.5.0.58

Sends the HTTP request to fetch the access token. When this method completes successfully, the access token is available in the AccessToken property. The connection is an existing connection to www.googleapis.com.

Important: Make sure your computer's date/time is accurately set to the current date/time, otherwise you'll get a 400 response status code with this error: Invalid JWT: Token must be a short-lived token (60 minutes) and in a reasonable timeframe. Check your iat and exp values and use a clock with skew to account for clock differences between systems..

Returns error.ChilkatFailed on failure; getLastErrorText explains why.

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SetP12
pub fn setP12(self: AuthGoogle, key: chilkat.Pfx) Error!void
Introduced in version 9.5.0.58

Sets the P12 private key to be used for obtaining an access token. An application must set either the P12 or JSON private key, but not both.

Returns error.ChilkatFailed on failure; getLastErrorText explains why.

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Events

All Chilkat methods are synchronous: the call returns when the work is done. During a call, AuthGoogle raises three events so your program can show progress and offer a way out. Declare any subset of abortCheck, percentDone and progressInfo in a struct of your own and install a pointer to it with setEventHandler:

const Progress = struct {
    pub fn percentDone(_: *Progress, pct: i32) bool {
        std.debug.print("{d}%\n", .{pct});
        return false; // return true to abort the method in progress
    }
    pub fn progressInfo(_: *Progress, name: [:0]const u8, value: [:0]const u8) void {
        std.debug.print("{s}: {s}\n", .{ name, value });
    }
};

var progress = Progress{};
auth_google.setEventHandler(&progress); // progress must outlive the installation
defer auth_google.clearEventHandler();
auth_google.setHeartbeatMs(250); // abortCheck 4 times per second during Chilkat calls
pub fn setEventHandler(self: AuthGoogle, handler: anytype) void

Installs handler, a pointer to any struct, as the receiver of this object's events, replacing any handler installed earlier. The dispatch is resolved at compile time: only the methods the struct declares are called, and a struct declaring none of the three is a compile error. The struct must stay alive, at the same address, until clearEventHandler or deinit.

pub fn clearEventHandler(self: AuthGoogle) void

Removes the handler; events are no longer delivered.

AbortCheck fires at regular intervals controlled by the HeartbeatMs property (0, the default, disables it); PercentDone fires when an operation's completion percentage is known; ProgressInfo delivers named progress values. Returning true from abortCheck or percentDone aborts the running method, which then returns error.ChilkatFailed.

Events fire on the thread that called the method, before that method returns. To abort a long operation from another thread, have abortCheck read a std.atomic.Value(bool), or set the object's AbortCurrent property.

AbortCheck
// handler struct method (optional); install with setEventHandler
pub fn abortCheck(self: *T) 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.

More Information and Examples

Example

const Abort = struct {
    stop: std.atomic.Value(bool) = .init(false),
    pub fn abortCheck(self: *Abort) bool {
        return self.stop.load(.acquire); // another thread may call abort.stop.store(true, .release)
    }
};

var abort = Abort{};
auth_google.setHeartbeatMs(250); // call abortCheck 4 times per second
auth_google.setEventHandler(&abort);
defer auth_google.clearEventHandler();
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PercentDone
// handler struct method (optional); install with setEventHandler
pub fn percentDone(self: *T, pct: i32) 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 pctDone 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 pctDone 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.

More Information and Examples

Example

const Progress = struct {
    pub fn percentDone(_: *Progress, pct: i32) bool {
        // pct ranges from 1 to 100.
        std.debug.print("Percent done: {d}\n", .{pct});
        return false; // return true to abort the method in progress
    }
};

var progress = Progress{};
auth_google.setEventHandler(&progress);
defer auth_google.clearEventHandler();
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ProgressInfo
// handler struct method (optional); install with setEventHandler
pub fn progressInfo(self: *T, name: [:0]const u8, value: [:0]const u8) void

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.

More Information and Examples

Example

const Info = struct {
    pub fn progressInfo(_: *Info, name: [:0]const u8, value: [:0]const u8) void {
        std.debug.print("{s}: {s}\n", .{ name, value });
    }
};

var info = Info{};
auth_google.setEventHandler(&info);
defer auth_google.clearEventHandler();
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