QCA

ciphertest.cpp
1 /*
2  Copyright (C) 2003 Justin Karneges <[email protected]>
3  Copyright (C) 2005-2006 Brad Hards <[email protected]>
4 
5  Permission is hereby granted, free of charge, to any person obtaining a copy
6  of this software and associated documentation files (the "Software"), to deal
7  in the Software without restriction, including without limitation the rights
8  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9  copies of the Software, and to permit persons to whom the Software is
10  furnished to do so, subject to the following conditions:
11 
12  The above copyright notice and this permission notice shall be included in
13  all copies or substantial portions of the Software.
14 
15  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18  AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
19  AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
20  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21 */
22 
23 // QtCrypto has the declarations for all of QCA
24 #include <QtCrypto>
25 #include <cstdio>
26 
27 #include <QCoreApplication>
28 
29 #ifdef QT_STATICPLUGIN
30 #include "import_plugins.h"
31 #endif
32 
33 int main(int argc, char **argv)
34 {
35  // the Initializer object sets things up, and
36  // also does cleanup when it goes out of scope
38 
39  QCoreApplication app(argc, argv);
40 
41  // we use the first argument if provided, or
42  // use "hello" if no arguments
43  QCA::SecureArray arg = (argc >= 2) ? argv[1] : "hello";
44 
45  // AES128 testing
46  if (!QCA::isSupported("aes128-cbc-pkcs7"))
47  printf("AES128-CBC not supported!\n");
48  else {
49  // Create a random key - you'd probably use one from another
50  // source in a real application
51  QCA::SymmetricKey key(16);
52 
53  // Create a random initialisation vector - you need this
54  // value to decrypt the resulting cipher text, but it
55  // need not be kept secret (unlike the key).
57 
58  // create a 128 bit AES cipher object using Cipher Block Chaining (CBC) mode
59  QCA::Cipher cipher(QStringLiteral("aes128"),
61  // use Default padding, which is equivalent to PKCS7 for CBC
63  // this object will encrypt
65  key,
66  iv);
67 
68  // we use the cipher object to encrypt the argument we passed in
69  // the result of that is returned - note that if there is less than
70  // 16 bytes (1 block), then nothing will be returned - it is buffered
71  // update() can be called as many times as required.
72  QCA::SecureArray u = cipher.update(arg);
73 
74  // We need to check if that update() call worked.
75  if (!cipher.ok()) {
76  printf("Update failed\n");
77  }
78  // output the results of that stage
79  printf("AES128 encryption of %s is [%s]\n", arg.data(), qPrintable(QCA::arrayToHex(u.toByteArray())));
80 
81  // Because we are using PKCS7 padding, we need to output the final (padded) block
82  // Note that we should always call final() even with no padding, to clean up
83  QCA::SecureArray f = cipher.final();
84 
85  // Check if the final() call worked
86  if (!cipher.ok()) {
87  printf("Final failed\n");
88  }
89  // and output the resulting block. The ciphertext is the results of update()
90  // and the result of final()
91  printf("Final block for AES128 encryption is [0x%s]\n", qPrintable(QCA::arrayToHex(f.toByteArray())));
92 
93  // re-use the Cipher t decrypt. We need to use the same key and
94  // initialisation vector as in the encryption.
95  cipher.setup(QCA::Decode, key, iv);
96 
97  // Build a single cipher text array. You could also call update() with
98  // each block as you receive it, if that is more useful.
99  QCA::SecureArray cipherText = u.append(f);
100 
101  // take that cipher text, and decrypt it
102  QCA::SecureArray plainText = cipher.update(cipherText);
103 
104  // check if the update() call worked
105  if (!cipher.ok()) {
106  printf("Update failed\n");
107  }
108 
109  // output results
110  printf("Decryption using AES128 of [0x%s] is %s\n",
111  qPrintable(QCA::arrayToHex(cipherText.toByteArray())),
112  plainText.data());
113 
114  // Again we need to call final(), to get the last block (with its padding removed)
115  plainText = cipher.final();
116 
117  // check if the final() call worked
118  if (!cipher.ok()) {
119  printf("Final failed\n");
120  }
121 
122  // output results
123  printf("Final decryption block using AES128 is %s\n", plainText.data());
124  // instead of update() and final(), you can do the whole thing
125  // in one step, using process()
126  printf("One step decryption using AES128: %s\n", QCA::SecureArray(cipher.process(cipherText)).data());
127  }
128 
129  return 0;
130 }
General class for cipher (encryption / decryption) algorithms.
Definition: qca_basic.h:581
SecureArray & append(const SecureArray &a)
Append a secure byte array to the end of this array.
char * data()
Pointer to the data in the secure array.
QByteArray toByteArray() const
Copy the contents of the secure array out to a standard QByteArray.
Container for keys for symmetric encryption algorithms.
Definition: qca_core.h:1263
QCA_EXPORT bool isSupported(const char *features, const QString &provider=QString())
Test if a capability (algorithm) is available.
Default for cipher-mode.
Definition: qca_basic.h:610
Container for initialisation vectors and nonces.
Definition: qca_core.h:1309
operate in Cipher Block Chaining mode
Definition: qca_basic.h:593
QCA_EXPORT QString arrayToHex(const QByteArray &array)
Convert a byte array to printable hexadecimal representation.
QCA_EXPORT void init()
Initialise QCA.
Secure array of bytes.
Definition: qca_tools.h:316
Operate in the "forward" direction; for example, encrypting.
Definition: qca_core.h:142
Operate in the "reverse" direction; for example, decrypting.
Definition: qca_core.h:143
Convenience method for initialising and cleaning up QCA.
Definition: qca_core.h:659
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