Encryption

1//
2// Copyright (c) 2001-2020 by PDFTron Systems Inc. All Rights Reserved.
3//
4
5using System;
6using System.Collections.Generic;
7using System.Linq;
8using System.Text;
9using System.Threading.Tasks;
10using System.IO;
11using Windows.Foundation;
12
13using pdftron.PDF;
14using pdftron.SDF;
15
16using PDFNetUniversalSamples.ViewModels;
17
18namespace PDFNetSamples
19{
20    public sealed class EncTestCS : Sample
21    {
22        public EncTestCS() :
23            base("Encryption Test", "Illustrates how to add password protection to a document and how to open it again.")
24        {
25        }
26
27        public override IAsyncAction RunAsync()
28        {
29            return Task.Run(new System.Action(async () =>
30            {
31                WriteLine("--------------------------------");
32                WriteLine("Starting Encryption Test...");
33                WriteLine("--------------------------------\n");
34
35                // Example 1: Securing a document with password protection and adjusting permissions 
36                // on the document.
37                try
38                {
39                    // Open the test file
40                    WriteLine("-------------------------------------------------");
41                    WriteLine("Securing an existing document...");
42
43                    String input_file_path = Path.Combine(InputPath, "fish.pdf");
44                    PDFDoc doc = new PDFDoc(input_file_path);
45
46                    if (!doc.InitSecurityHandler())
47                    {
48                        WriteLine("Document authentication error...");
49                        return;
50                    }
51
52
53                    SecurityHandler new_handler = new SecurityHandler();
54
55                    string my_password = "test";
56                    new_handler.ChangeUserPassword(my_password);
57
58                    new_handler.SetPermission(SecurityHandlerPermission.e_print, true);
59                    new_handler.SetPermission(SecurityHandlerPermission.e_extract_content, false);
60
61                    doc.SetSecurityHandler(new_handler);
62
63                    WriteLine(string.Format("\nTo open document use password: {0}\n", my_password));
64
65                    String output_file_path = Path.Combine(OutputPath, "secured.pdf");
66                    await doc.SaveAsync(output_file_path, 0);
67
68                    WriteLine("Done. Result saved in " + output_file_path);
69                    await AddFileToOutputList(output_file_path).ConfigureAwait(false);
70
71                }
72                catch (Exception e)
73                {
74                    WriteLine(GetExceptionMessage(e));
75                }
76
77
78                // Example 2: Reading password protected document without user feedback.
79                try
80                {
81                    WriteLine("-------------------------------------------------");
82                    WriteLine("Open the password protected document from the first example...");
83
84                    String input_file_path = Path.Combine(OutputPath, "secured.pdf");
85                    PDFDoc doc = new PDFDoc(input_file_path);   // Open the encrypted document that we saved in the first example. 
86
87                    if (!doc.InitStdSecurityHandler("test"))
88                    {
89                        WriteLine("Document authentication error...");
90                        WriteLine("The password is not valid.");
91                        return;
92                    }
93                    else
94                    {
95                        WriteLine("The password is correct! Document can now be used for reading and editing");
96
97                        // Remove the password security and save the changes to a new file.
98                        doc.SetSecurityHandler(null);
99
100                        String output_file_path = Path.Combine(OutputPath, "secured_nomore1.pdf");
101                        await doc.SaveAsync(output_file_path, 0);
102
103                        WriteLine("Done. Result saved in " + output_file_path);
104                        await AddFileToOutputList(output_file_path).ConfigureAwait(false);
105                        
106                        WriteLine("Done. Result saved in secured_nomore1.pdf");
107
108                        
109                    }
110                }
111                catch (Exception e)
112                {
113                    WriteLine(GetExceptionMessage(e));
114                }
115
116                WriteLine("\n--------------------------------");
117                WriteLine("To see how to open a document with user feedback, see the PDFViewCtrlDemo and the Open and HandlePassword functions.");
118                WriteLine("--------------------------------\n");
119
120                WriteLine("\n--------------------------------");
121                WriteLine("Done Encryption Test.");
122                WriteLine("--------------------------------\n");
123            })).AsAsyncAction();
124        }
125    }
126}