.NET Core C# Requires Chilkat v11.7.0+

Extract Text from a Password-Protected PDF

See more PDF Text Extraction Examples

Demonstrates extracting text from a PDF that requires a password to open. The PDF loads without the password (its structure can be read), but the "text" operation fails because the content cannot be decrypted; "assess" reports that a password is required. With the UserPassword property set before loading, extraction works normally. .NET Core C#

bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  The PDF used in this example (user password: secret) is available at encrypted_user_password.pdf

Chilkat.Pdf pdf = new Chilkat.Pdf();
Chilkat.JsonObject json = new Chilkat.JsonObject();
Chilkat.JsonObject jsonOut = new Chilkat.JsonObject();

//  The PDF loads without its password: the file's structure is readable, so properties such as
//  NumPages and the security settings are available...
success = pdf.LoadFile("qa_data/pdf/encrypted_user_password.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

//  ...but the content cannot be decrypted, so extracting text fails.
success = pdf.ExtractText("text",json,jsonOut);
if (success == false) {
    Debug.WriteLine("Cannot extract: " + pdf.LastErrorText);
}

//  "assess" still works: it reports that a password is required and nothing else.
success = pdf.ExtractText("assess",json,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("passwordRequired: " + Convert.ToString(jsonOut.BoolOf("quality.passwordRequired")));
Debug.WriteLine("rating: " + jsonOut.StringOf("quality.rating"));

//  Set the password and load again.
pdf.UserPassword = "secret";
success = pdf.LoadFile("qa_data/pdf/encrypted_user_password.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

success = pdf.ExtractText("text",json,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine(jsonOut.StringOf("text"));

//  Sample output:

//  Cannot extract: ChilkatLog:
//    ExtractText:
//      ...
//        The PDF is encrypted and could not be opened (wrong or missing password); its text cannot be read.
//      ...
//  passwordRequired: true
//  rating: none
//  Board Minutes (Confidential)
//  
//  The board met on 3 November 2026. Present: the chair, the treasurer and four members. The treasurer reported that spending for the season came in under budget.
//  
//  The meeting closed at 8.45 p.m.