CodeSign Dart Reference Documentation

CkCodeSign

Current Version: 11.6.1

Chilkat.CodeSign

Sign, verify, inspect, and remove Authenticode signatures on Windows executables.

Chilkat.CodeSign works directly with Authenticode signatures on Windows executable files such as .exe and .dll. It provides functionality for applying a code-signing signature, validating whether a signed executable can be trusted, extracting signature information, retrieving the signer certificate, and removing an existing signature.

Sign EXE and DLL files

Apply Authenticode signatures to Windows executable files using a certificate and associated private key.

Validate trust

Check whether a signed executable has a valid signature and whether the signing certificate chain can be trusted.

Inspect signatures

Extract details about the Authenticode signature, including signer information and signature-related metadata.

Retrieve signer certificates

Get the certificate used to sign the executable and inspect it with Chilkat.Cert.

Remove signatures

Remove an existing Authenticode signature from a Windows executable when an unsigned output file is required.

Diagnostics

Use detailed diagnostic output to troubleshoot signing, certificate, trust-chain, timestamping, or validation problems.

Common pattern: Load or provide a code-signing certificate that has access to its private key, sign the target .exe or .dll, optionally add timestamping if supported by the signing workflow, then verify the resulting signature and inspect diagnostics if validation does not succeed.

Object Creation

// pubspec.yaml:
//     dependencies:
//       chilkat: ^11.6.1

import 'package:chilkat/chilkat.dart';

// Once per process, before any other Chilkat call:
Chilkat.unlockBundle('Anything for 30-day trial');   // shorthand for CkGlobal().unlockBundle(..)

final codeSign = CkCodeSign();
// ... the native object is released when `codeSign` is garbage collected, or now with codeSign.dispose().
CkCodeSign CkCodeSign()

Creates the underlying native Chilkat object. Use a CkCodeSign only from the isolate that created it: Chilkat objects cannot be sent between isolates. Every call is synchronous; in a Flutter app, run long operations (network, large files) inside Isolate.run, creating the Chilkat objects inside the isolate.

void dispose()

Releases the native object immediately instead of waiting for garbage collection (useful for a large CkBinData or an open socket). Calling it more than once is harmless; any other use of the object afterwards throws a StateError. isDisposed tells whether it has been called.

Errors

A method that can fail throws a ChilkatException: a method whose only outcome is success or failure returns void and throws on failure; a method producing a String or an object returns it and throws where Chilkat would have returned null. The exception carries the object's LastErrorText at the time of the failure (lastErrorText), the class and method names (className, methodName) and a one-line message. Properties never throw, and methods that answer a question (has..., is..., ...) return a plain bool.

try {
  codeSign.someMethod(...);
} on ChilkatException catch (e) {
  print(e);                // CkCodeSign.someMethod failed: <reason>
  print(e.lastErrorText);  // the full Chilkat log of the failed call
}

Properties

DebugLogFilePath
// read/write
String get debugLogFilePath
set debugLogFilePath(String value)

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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HeartbeatMs
// read/write
int get heartbeatMs
set heartbeatMs(int value)
Introduced in version 9.5.0.98

Specifies the approximate interval, in milliseconds, between AbortCheck event callbacks during supported operations. An event handler can request that the current operation be aborted.

The default is 0, which disables AbortCheck callbacks. Setting a positive value enables periodic callbacks when an operation is sufficiently long-running; methods that finish quickly may complete without generating one.

Callback interval: The interval is a scheduling target rather than a real-time guarantee. Callback timing can vary while waiting for private-key hardware, a timestamp authority, certificate-chain processing, or other operating-system services.

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LastErrorHtml
// read-only
String get 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.

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LastErrorText
// read-only
String get lastErrorText

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
String get 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.

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LastMethodSuccess
// read/write
bool get lastMethodSuccess
set lastMethodSuccess(bool value)

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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UncommonOptions
// read/write
String get uncommonOptions
set uncommonOptions(String value)
Introduced in version 9.5.0.97

Provides a comma-separated list of specialized compatibility or validation options. The default is an empty string, which is appropriate for normal use.

OptionEffect
codesign-allow-expired-certPrevents Authenticode verification from failing solely because the signing certificate is expired.
Use only for an explicit trust policy: This option relaxes the certificate-expiration check; it does not disable file-integrity, signature, chain, or other validation checks. It is not a substitute for timestamping. A signature carrying a valid trusted timestamp should ordinarily remain verifiable after the signing certificate expires without this option.

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VerboseLogging
// read/write
bool get verboseLogging
set verboseLogging(bool value)

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
String get version

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

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Methods

AddSignature
void addSignature(String path, CkCert cert, CkJsonObject options)
Introduced in version 9.5.0.97

Adds a Microsoft Authenticode signature to the Windows executable or DLL specified by path. The file is modified in place. cert supplies the code-signing certificate and must provide access to its associated private key. options supplies the signing configuration as JSON.

Common options options include:

JSON memberPurpose
hashAlgSelects the file-digest algorithm, such as sha256.
timestampToken.enabledEnables an RFC 3161 timestamp token.
timestampToken.tsaUrlSpecifies the timestamp authority URL.
timestampToken.requestTsaCertRequests inclusion of the timestamp authority certificate.
timestampToken.hashAlgSelects the timestamp-request digest algorithm, such as sha256.
{
  "hashAlg": "sha256",
  "timestampToken": {
    "enabled": true,
    "tsaUrl": "http://timestamp.example.com",
    "requestTsaCert": true,
    "hashAlg": "sha256"
  }
}
Timestamping is strongly recommended: A trusted timestamp records that the signature existed while the code-signing certificate was valid. This normally allows the signature to continue validating after the signing certificate expires, provided the timestamp and certificate chains remain valid under the verifier's trust policy.

Returns normally on success; throws a ChilkatException on failure.

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GetSignerCert
void getSignerCert(CkCert cert)
Introduced in version 10.0.1

Retrieves the X.509 signer certificate discovered by the most recent call to VerifySignature on this CodeSign object. If the certificate is fully available, cert is loaded with it and the method returns true. Otherwise, the method returns false.

The returned object contains the public certificate only; it does not provide the signer's private key. Call this method after VerifySignature and use the same CodeSign instance.

Certificate retrieval versus trust: Successfully retrieving the signer certificate does not independently validate the signature or establish trust. Use the result of VerifySignature and the returned signature information when making a trust decision.

Returns normally on success; throws a ChilkatException on failure.

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RemoveSignature
void removeSignature(String path)
Introduced in version 9.5.0.97

Removes the embedded Authenticode signature from the Windows executable or DLL specified by path. The file is modified in place. Returns true if the signature is successfully removed; otherwise returns false.

Effect of removal: The resulting file is no longer Authenticode-signed and no longer carries the removed publisher and timestamp information. This operation does not delete the signing certificate from a Windows certificate store or alter the private key. Keep a backup when the original signed file must be retained.

Returns normally on success; throws a ChilkatException on failure.

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VerifySignature
void verifySignature(String path, CkJsonObject sigInfo)
Introduced in version 9.5.0.97

Verifies the embedded Microsoft Authenticode signature of the Windows executable or DLL specified by path. Structured information about the signature, signer, certificate chain, digest algorithms, timestamp, and validation result is written to sigInfo.

Returns true when the signature satisfies the applicable Authenticode validation checks under the current Windows trust configuration. This includes confirming that the signed portions of the file have not changed and evaluating the signing certificate and timestamp information, as applicable. An unsigned file or a signature that does not validate causes the method to return false. Inspect sigInfo and LastErrorText for details.

What successful verification means: Authenticode verifies publisher identity, file integrity, and certificate trust according to the validation policy. It does not prove that the software is bug-free, safe to execute, or free of malicious behavior. Trust results can also depend on the Windows trusted-root store, certificate-chain availability, timestamp validity, revocation policy, and other system trust settings.

Returns normally on success; throws a ChilkatException on failure.

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Events

All Chilkat methods are synchronous: the call returns when the work is done. During a call, CkCodeSign raises three events so your application can show progress and offer a way out. Each event is a nullable callback property on the object; assign a function to receive it, or null to stop receiving it:

final codeSign = CkCodeSign();
codeSign.onPercentDone = (pct) {
  print('$pct%');
  return false;   // return true to abort the method in progress
};
codeSign.onProgressInfo = (name, value) => print('$name: $value');
codeSign.heartbeatMs = 250;   // raise onAbortCheck 4 times per second during Chilkat calls
codeSign.onAbortCheck = () => _userPressedCancel;

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 onAbortCheck or onPercentDone aborts the running method, which then throws a ChilkatException.

Events fire on the thread that called the method, before that method returns. An exception thrown inside a callback aborts the running method and is rethrown from it once the native library has returned. In a Flutter app the callbacks run inside the worker isolate that owns the object; forward progress to the UI through a SendPort, and let onAbortCheck read a flag the UI sets the same way.

AbortCheck
// callback property; return true to abort the method in progress
bool Function()? onAbortCheck

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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Example:

codeSign.heartbeatMs = 250;   // call onAbortCheck 4 times per second

var cancelRequested = false;
codeSign.onAbortCheck = () => cancelRequested;
// ... set cancelRequested = true (e.g. from a message received on a ReceivePort) to abort the method in progress
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PercentDone
// callback property; return true to abort the method in progress
bool Function(int pctDone)? onPercentDone

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:

codeSign.onPercentDone = (pct) {
  // pct ranges from 1 to 100.
  print('Percent done: $pct');
  return false;   // return true to abort the method in progress
};
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ProgressInfo
// callback property
void Function(String name, String value)? onProgressInfo

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:

codeSign.onProgressInfo = (name, value) => print('$name: $value');
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