Class PdfSignatureExtensions

Extension methods for PdfSignature to sign PDF files directly without loading into memory. Provides convenient file-based signing operations for batch processing.

Example - Sign PDF file:

var signature = new PdfSignature("certificate.pfx", "password");
signature.SignPdfFile("document.pdf", removeOldSignatures: true);

Inheritance

System.Object

PdfSignatureExtensions

Namespace: IronPdf.Signing

Assembly: IronPdf.dll

Syntax

public static class PdfSignatureExtensions : Object

Remarks

Related Resources:

Methods

SignPdfFile(PdfSignature, String, Boolean, String, String)

Digitally signs an existing PDF file using the specified certificate. The file is loaded, signed, and saved back to the same path.

Example:

var signature = new PdfSignature("certificate.pfx", "password");
// Sign single file:
signature.SignPdfFile("contract.pdf");
// Sign encrypted PDF with old signatures removed:
signature.SignPdfFile("encrypted.pdf",
removeOldSignatures: true,
userPassword: "user123",
ownerPassword: "owner456");
// Batch sign multiple files:
foreach (var file in Directory.GetFiles("contracts", "*.pdf"))
{
signature.SignPdfFile(file, removeOldSignatures: true);
}

Declaration

public static bool SignPdfFile(this PdfSignature signature, string pdfFilePath, bool removeOldSignatures = false, string userPassword = null, string ownerPassword = null)

Parameters

Type	Name	Description
PdfSignature	signature	The PdfSignature certificate to use for signing.
System.String	pdfFilePath	Full or relative path to the PDF file to sign.
System.Boolean	removeOldSignatures	If true, removes existing digital signatures before signing. Required for documents with invalid or expired signatures (default: false).
System.String	userPassword	User password if the PDF is encrypted for viewing (default: null).
System.String	ownerPassword	Owner password if the PDF has restricted permissions (default: null).

Returns

Type	Description
System.Boolean	true if signing completed successfully.

See Also

PdfSignature