AuthGoogle Rust Reference Documentation
AuthGoogle
Current Version: 11.6.1
Chilkat.AuthGoogle
Authenticate server-to-server using a Google service account rather than
an interactive browser-based user consent flow.
Load service account credentials from modern JSON private keys or from
legacy P12 private key files.
Specify the OAuth scopes required by the target Google API and add custom
JWT claims when needed.
Use domain-wide delegation by setting a subject email when the service
account is authorized to act on behalf of a Google Workspace user.
Inspect the generated access token, expiration time, remaining lifetime,
and validity state before using or refreshing credentials.
Pass the resulting bearer token to Chilkat HTTP, REST, storage, mail, or
other Google API request workflows.
For an extended overview, see
AuthGoogle Class Overview.
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
JSON or P12 keys
Scopes and claims
Delegated user access
Access-token tracking
Chilkat API integration
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
// Cargo.toml:
// [dependencies]
// chilkat = "11.6"
use chilkat::AuthGoogle;
// Once per process, before any other Chilkat call:
chilkat::unlock_bundle("Anything for 30-day trial")?; // shorthand for Global::new().unlock_bundle(..)
let auth_google = AuthGoogle::new();
// ... the native object is freed when `auth_google` goes out of scope.Creates the underlying native Chilkat object (AuthGoogle also implements Default). Every method takes &self, so the object never needs to be declared mut. A AuthGoogle is Send but not Sync: it may be moved to another thread, but a reference to it cannot be shared between threads at the same time.
The native object is freed when the AuthGoogle is dropped — when it goes out of scope, or explicitly with drop(auth_google). There is no Dispose method to call.
Errors
Methods that can fail return chilkat::Result<T>, which is Result<T, chilkat::Error>: a method whose only outcome is success or failure returns Result<()>, a method producing a string or an object returns Result<String> or Result<AuthGoogle>. The error carries the object's LastErrorText at the time of the failure (Error::last_error_text), the class and method names, and implements std::error::Error, so ? works in any function returning chilkat::Result or a Box<dyn Error>. Properties never fail, and methods that answer a question (has_..., is_..., ...) return a plain bool.
match auth_google.some_method(...) {
Ok(value) => println!("{value:?}"),
Err(e) => eprintln!("{}", e.last_error_text()),
}Properties
AccessToken
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.
topDebugLogFilePath
pub fn debug_log_file_path(&self) -> String
pub fn set_debug_log_file_path(&self, value: &str)
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.
EmailAddress
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.
ExpireNumSeconds
pub fn expire_num_seconds(&self) -> i32
pub fn set_expire_num_seconds(&self, value: i32)
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.
topIat
pub fn iat(&self) -> i32
pub fn set_iat(&self, value: i32)
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.
topJsonKey
The JSON key for obtaining an access token. An application must set either the P12 or JSON private key, but not both.
LastErrorHtml
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.
topLastErrorText
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.
LastErrorXml
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.
topLastMethodSuccess
pub fn last_method_success(&self) -> bool
pub fn set_last_method_success(&self, value: 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.
NumSecondsRemaining
pub fn num_seconds_remaining(&self) -> i32
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.
topScope
A space-delimited list of the permissions that the application requests.
topSubEmailAddress
pub fn sub_email_address(&self) -> String
pub fn set_sub_email_address(&self, value: &str)
The email address of the user for which the application is requesting delegated access.
topValid
pub fn valid(&self) -> bool
true if the AccessToken property contains a valid non-expired access token obtained via the call to ObtainAccessToken.
VerboseLogging
pub fn verbose_logging(&self) -> bool
pub fn set_verbose_logging(&self, value: 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.
Version
Methods
AddClaims
Adds additional custom claims to the JWT claims set.
Returns Ok(()) for success, Err(chilkat::Error) for failure.
GetP12
Returns the private key in a PFX (P12) object. This is only possible if the private key was previously set by calling SetP12.
Returns Err(chilkat::Error) on failure.
ObtainAccessToken
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 Ok(()) for success, Err(chilkat::Error) for failure.
SetP12
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 Ok(()) for success, Err(chilkat::Error) for failure.
Events
All Chilkat methods are synchronous: the call returns when the work is done. During a call, AuthGoogle raises three events so your application can show progress and offer a way out. Implement the chilkat::EventHandler trait (every method has a do-nothing default, so implement only the events you need) and install it with set_event_handler:
use chilkat::{AuthGoogle, EventHandler};
struct Progress;
impl EventHandler for Progress {
fn percent_done(&mut self, pct: i32) -> bool {
println!("{pct}%");
false // return true to abort the method in progress
}
fn progress_info(&mut self, name: &str, value: &str) {
println!("{name}: {value}");
}
}
let auth_google = AuthGoogle::new();
auth_google.set_event_handler(Progress);
auth_google.set_heartbeat_ms(250); // raise abort_check 4 times per second during Chilkat callsFor a one-off handler the closure methods avoid writing a type; they may be combined, and each replaces the previously set closure for that one event (installing a closure removes a trait handler set earlier, and vice versa):
auth_google.on_percent_done(|pct| { println!("{pct}%"); false });
auth_google.on_progress_info(|name, value| println!("{name}: {value}"));Installs handler as the receiver of this object's events, replacing any handler or closures set earlier. The object owns the handler, which must be Send + 'static.
Removes the handler and any closures; 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 abort_check or percent_done aborts the running method, which then returns Err.
Events fire on the thread that called the method, before that method returns. A panic inside a handler aborts the running method and is re-raised to the caller once the native library has returned, so it never unwinds through C frames. To abort a long operation from another thread, share an Arc<AtomicBool> with an abort_check handler, or set the object's AbortCurrent property to true.
AbortCheck
fn abort_check(&mut self) -> 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.
Example (closure form; the EventHandler trait method is equivalent):
auth_google.set_heartbeat_ms(250); // call abort_check 4 times per second
let stop = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
let flag = stop.clone();
auth_google.on_abort_check(move || flag.load(std::sync::atomic::Ordering::Relaxed));
// ... another thread may now abort the method in progress with stop.store(true, Ordering::Relaxed)PercentDone
fn percent_done(&mut self, 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 pct_done 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 pct_done 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.
Example (closure form; the EventHandler trait method is equivalent):
auth_google.on_percent_done(|pct| {
// pct ranges from 1 to 100.
println!("Percent done: {pct}");
false // return true to abort the method in progress
});ProgressInfo
fn progress_info(&mut self, name: &str, value: &str)
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.
Example (closure form; the EventHandler trait method is equivalent):
auth_google.on_progress_info(|name, value| println!("{name}: {value}"));