> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/uwp/security/decrypt.md).

# Decrypt & read a PDF document in UWP

Guide to read a PDF document with password protection.

To read a PDF document with password protection.

{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}

```csharp
PDFDoc doc = new PDFDoc(filename);

// At this point MySecurityHandler callbacks will be invoked.
// MySecurityHandler.GetAuthorizationData() should collect the password and
// AuthorizeFailed() is called if user repeatedly enters a wrong password.
if (doc.InitStdSecurityHandler(password)) {
  // The password is correct! Document can now be used for reading and editing
}
```

{% endcode %}
{% endtab %}
{% endtabs %}

[Encrypt and Decrypt PDF Files](/uwp/get-started/samples.md#encryption) Full sample code which illustrates some of our encryption support.

## About reading a secured document

Apryse SDK fully supports the reading of secured and encrypted PDF documents. To test whether a document requires a password, check the return value of `PDFDoc.InitSecurityHandler()` as shown above. Because `InitSecurityHandler()` doesn't have any side effects on documents that are not encrypted you should always invoke this method, or `InitStdSecurityHandler()`, after constructing a document.

If a document doesn't require authentication data (such as a user password) in order to view its content, `InitSecurityHandler()` is enough to work with encrypted documents. If, on the other hand, the document requires a password, `InitStdSecurityHandler` allows you to provide one.

After the document's security handler is initialized, you can access it using the `doc.GetSecurityHandler()` method. You can edit permissions and authorization data on an existing handler, or set a completely new security handler using the `doc.SetSecurityHandler(handler)` method.

## Removing security from a document

To **remove** PDF security, call the `RemoveSecurity()` method:

{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}

```csharp
PDFDoc doc = new PDFDoc(filename);
doc.InitSecurityHandler();
doc.RemoveSecurity();
```

{% endcode %}
{% endtab %}
{% endtabs %}

A document may have both a current and a new security handler associated with it because a PDF document is not fully loaded in memory and decrypted when it is loaded. To fully decrypt the document, even after applying a new security handler, the original security handler is still required.

## PDF security permissions

The security mechanism for the high-level document works in the same way as with an SDF document. To secure a document, use the `PDFDoc.SetSecurityHandler()` method. To open a secured document, call `PDFDoc.InitSecurityHandler()`. To open a document with a password, call `PDFDoc.InitStdSecurityHandler()`.

The following table lists security permissions available through the standard security handler:

| Permission          | Description                                                                                                                                                                                                                                          |
| ------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| e\_owner            | All permissions are granted.                                                                                                                                                                                                                         |
| e\_doc\_open        | A permission to open a document.                                                                                                                                                                                                                     |
| e\_doc\_modify      | Modify the contents of the document.                                                                                                                                                                                                                 |
| e\_print            | Print the document.                                                                                                                                                                                                                                  |
| e\_print\_high      | Print the document to a representation from which a faithful digital copy of the PDF content could be generated. When this permission is not set, printing is limited to a low level representation of the appearance, possibly of degraded quality. |
| e\_extract\_content | Copy or otherwise extract text and graphics from the document.                                                                                                                                                                                       |
| e\_mod\_annot       | Add or modify text annotations, fill in interactive form fields.                                                                                                                                                                                     |
| e\_fill\_forms      | Fill in existing interactive form fields (including signature fields).                                                                                                                                                                               |
| e\_access\_support  | Extract text and graphics (in support of accessibility to disabled users or for other purposes).                                                                                                                                                     |
| e\_assemble\_doc    | Assemble the document (insert, rotate, or delete pages and create bookmarks or thumbnail images), even if e\_doc\_modify is not set.                                                                                                                 |


---

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