Android Guides Digital signature

Digital Signatures

ComPDFKit_Tools provides signature field interaction, certificate import and creation, appearance settings, and validation information. For direct file operations, see Digital Signatures.

Show the Signature Toolbar

Use ToolbarConfig to control toolbar visibility in signature mode:

{
  "toolbarConfig": {
    "signatureToolbarVisible": true
  }
}

CSignatureToolBar is in com.compdfkit.tools.signature.

Sign Through the UI

1. Create a signature field (signaturesFields) in form mode or use an existing unsigned field.
2. Tap the field and select digital certificate signing. Handwritten or image-based electronic signatures are a separate operation.
3. Import a .p12 or .pfx certificate or use the certificate creation UI.
4. Enter the certificate password, configure appearance and signing information, choose the output location, and apply the signature.
5. Open the output to inspect signature and certificate validation information.

To create certificates through the API, see Create Digital Certificates. For custom fields and appearance, see Create Digital Signatures.

Validation Information and Components

Tools displays signature integrity, document modification, certificate trust, and expiry information. Read the SDK's complete report when applying a custom signature acceptance policy.

Component	Purpose
CSignatureToolBar	Signature mode toolbar
CImportCertificateDigitalDialog	Certificate import UI
CreateCertificateDigitalDialog	Certificate creation UI
CDigitalSignStylePreviewDialog	Signature appearance preview
CPDFCertDigitalSignListDialog	Document signature list
CertDigitalSignInfoDialog	Signature information UI

Timestamp and Long-Term Validation Status

The 3.2.0 signature information UI adds embedded timestamp and LTV-related status. The default Tools signing flow calls writeSignature() without a TSA address and does not automatically request an embedded timestamp.

Information	Interpretation
Embedded timestamp	Indicates timestamp-related information is present; assess trust through the report
Document LTV material readiness	Checks DSS/VRI material completeness with CPDFLtvService.assessReadiness(document)
Signature validity and trust	Based on integrity, document changes, certificates, and related validation results

Document-level readiness does not mean each signature passed long-term validation. For signature-level LTV results, use the report in Verify Digital Signatures with revocation and LTV checks enabled.

For TSA requests in a custom flow, see Digital Signature Timestamps. To add materials to signed files, see Long-Term Validation and PAdES Signing.