snipt

Ctrl+h for KB shortcuts

C#

AES encryption

byte[] plainTextBytes;
RijndaelManaged aesAlgorithm;
ICryptoTransform encryptor;
MemoryStream memStream;
CryptoStream cryptoStream;
byte[] cipherTextBytes;

// Convert the plainText string into a byte array
plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText);

// Prepare the AES algorithm with the correct settings
aesAlgorithm = new RijndaelManaged(); // Rijndael are the authors of AES and Microsoft use this as their AES class
aesAlgorithm.Mode = CipherMode.CBC; // Sendible uses CBC mode
aesAlgorithm.Padding = PaddingMode.PKCS7; // Sendible uses PKCS7 padding

// Create an aes encryptor with the key and iv
encryptor = aesAlgorithm.CreateEncryptor(this.sharedKeyBytes, this.sharedIVBytes);

// Create a memory stream so that the encrypted cipher text can be read out to memory
memStream = new MemoryStream();

// Create a crypto stream to aes encrypt the plain text through to the memory stream
cryptoStream = new CryptoStream(memStream, encryptor, CryptoStreamMode.Write);

// Write the plain text to the crypto stream and ensure the final block is flushed
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();

// Read the encrypted cipher text from the memory stream to an array of bytes
// and close both the memory and crypto streams. Also explicitly nullify all encryption
// objects
cipherTextBytes = memStream.ToArray();
memStream.Close();
cryptoStream.Close();
cryptoStream = null;
memStream = null;
encryptor = null;
aesAlgorithm = null;
https://snipt.net/embed/2a745445ec6abbeb7c1438f624fb5f0f/
/raw/2a745445ec6abbeb7c1438f624fb5f0f/
2a745445ec6abbeb7c1438f624fb5f0f
csharp
C#
38
2019-08-23T06:49:02
True
False
False
Nov 02, 2012 at 01:51 PM
/api/public/snipt/49522/
aes-encryption
<table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><a href="#L-1"> 1</a> <a href="#L-2"> 2</a> <a href="#L-3"> 3</a> <a href="#L-4"> 4</a> <a href="#L-5"> 5</a> <a href="#L-6"> 6</a> <a href="#L-7"> 7</a> <a href="#L-8"> 8</a> <a href="#L-9"> 9</a> <a href="#L-10">10</a> <a href="#L-11">11</a> <a href="#L-12">12</a> <a href="#L-13">13</a> <a href="#L-14">14</a> <a href="#L-15">15</a> <a href="#L-16">16</a> <a href="#L-17">17</a> <a href="#L-18">18</a> <a href="#L-19">19</a> <a href="#L-20">20</a> <a href="#L-21">21</a> <a href="#L-22">22</a> <a href="#L-23">23</a> <a href="#L-24">24</a> <a href="#L-25">25</a> <a href="#L-26">26</a> <a href="#L-27">27</a> <a href="#L-28">28</a> <a href="#L-29">29</a> <a href="#L-30">30</a> <a href="#L-31">31</a> <a href="#L-32">32</a> <a href="#L-33">33</a> <a href="#L-34">34</a> <a href="#L-35">35</a> <a href="#L-36">36</a> <a href="#L-37">37</a> <a href="#L-38">38</a></pre></div></td><td class="code"><div class="highlight"><pre><span></span><span id="L-1"><a name="L-1"></a><span class="kt">byte</span><span class="p">[]</span> <span class="n">plainTextBytes</span><span class="p">;</span> </span><span id="L-2"><a name="L-2"></a><span class="n">RijndaelManaged</span> <span class="n">aesAlgorithm</span><span class="p">;</span> </span><span id="L-3"><a name="L-3"></a><span class="n">ICryptoTransform</span> <span class="n">encryptor</span><span class="p">;</span> </span><span id="L-4"><a name="L-4"></a><span class="n">MemoryStream</span> <span class="n">memStream</span><span class="p">;</span> </span><span id="L-5"><a name="L-5"></a><span class="n">CryptoStream</span> <span class="n">cryptoStream</span><span class="p">;</span> </span><span id="L-6"><a name="L-6"></a><span class="kt">byte</span><span class="p">[]</span> <span class="n">cipherTextBytes</span><span class="p">;</span> </span><span id="L-7"><a name="L-7"></a> </span><span id="L-8"><a name="L-8"></a><span class="c1">// Convert the plainText string into a byte array</span> </span><span id="L-9"><a name="L-9"></a><span class="n">plainTextBytes</span> <span class="p">=</span> <span class="n">System</span><span class="p">.</span><span class="n">Text</span><span class="p">.</span><span class="n">Encoding</span><span class="p">.</span><span class="n">UTF8</span><span class="p">.</span><span class="n">GetBytes</span><span class="p">(</span><span class="n">plainText</span><span class="p">);</span> </span><span id="L-10"><a name="L-10"></a> </span><span id="L-11"><a name="L-11"></a><span class="c1">// Prepare the AES algorithm with the correct settings</span> </span><span id="L-12"><a name="L-12"></a><span class="n">aesAlgorithm</span> <span class="p">=</span> <span class="k">new</span> <span class="n">RijndaelManaged</span><span class="p">();</span> <span class="c1">// Rijndael are the authors of AES and Microsoft use this as their AES class</span> </span><span id="L-13"><a name="L-13"></a><span class="n">aesAlgorithm</span><span class="p">.</span><span class="n">Mode</span> <span class="p">=</span> <span class="n">CipherMode</span><span class="p">.</span><span class="n">CBC</span><span class="p">;</span> <span class="c1">// Sendible uses CBC mode</span> </span><span id="L-14"><a name="L-14"></a><span class="n">aesAlgorithm</span><span class="p">.</span><span class="n">Padding</span> <span class="p">=</span> <span class="n">PaddingMode</span><span class="p">.</span><span class="n">PKCS7</span><span class="p">;</span> <span class="c1">// Sendible uses PKCS7 padding</span> </span><span id="L-15"><a name="L-15"></a> </span><span id="L-16"><a name="L-16"></a><span class="c1">// Create an aes encryptor with the key and iv</span> </span><span id="L-17"><a name="L-17"></a><span class="n">encryptor</span> <span class="p">=</span> <span class="n">aesAlgorithm</span><span class="p">.</span><span class="n">CreateEncryptor</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="n">sharedKeyBytes</span><span class="p">,</span> <span class="k">this</span><span class="p">.</span><span class="n">sharedIVBytes</span><span class="p">);</span> </span><span id="L-18"><a name="L-18"></a> </span><span id="L-19"><a name="L-19"></a><span class="c1">// Create a memory stream so that the encrypted cipher text can be read out to memory</span> </span><span id="L-20"><a name="L-20"></a><span class="n">memStream</span> <span class="p">=</span> <span class="k">new</span> <span class="n">MemoryStream</span><span class="p">();</span> </span><span id="L-21"><a name="L-21"></a> </span><span id="L-22"><a name="L-22"></a><span class="c1">// Create a crypto stream to aes encrypt the plain text through to the memory stream</span> </span><span id="L-23"><a name="L-23"></a><span class="n">cryptoStream</span> <span class="p">=</span> <span class="k">new</span> <span class="n">CryptoStream</span><span class="p">(</span><span class="n">memStream</span><span class="p">,</span> <span class="n">encryptor</span><span class="p">,</span> <span class="n">CryptoStreamMode</span><span class="p">.</span><span class="n">Write</span><span class="p">);</span> </span><span id="L-24"><a name="L-24"></a> </span><span id="L-25"><a name="L-25"></a><span class="c1">// Write the plain text to the crypto stream and ensure the final block is flushed</span> </span><span id="L-26"><a name="L-26"></a><span class="n">cryptoStream</span><span class="p">.</span><span class="n">Write</span><span class="p">(</span><span class="n">plainTextBytes</span><span class="p">,</span> <span class="m">0</span><span class="p">,</span> <span class="n">plainTextBytes</span><span class="p">.</span><span class="n">Length</span><span class="p">);</span> </span><span id="L-27"><a name="L-27"></a><span class="n">cryptoStream</span><span class="p">.</span><span class="n">FlushFinalBlock</span><span class="p">();</span> </span><span id="L-28"><a name="L-28"></a> </span><span id="L-29"><a name="L-29"></a><span class="c1">// Read the encrypted cipher text from the memory stream to an array of bytes</span> </span><span id="L-30"><a name="L-30"></a><span class="c1">// and close both the memory and crypto streams. Also explicitly nullify all encryption</span> </span><span id="L-31"><a name="L-31"></a><span class="c1">// objects</span> </span><span id="L-32"><a name="L-32"></a><span class="n">cipherTextBytes</span> <span class="p">=</span> <span class="n">memStream</span><span class="p">.</span><span class="n">ToArray</span><span class="p">();</span> </span><span id="L-33"><a name="L-33"></a><span class="n">memStream</span><span class="p">.</span><span class="n">Close</span><span class="p">();</span> </span><span id="L-34"><a name="L-34"></a><span class="n">cryptoStream</span><span class="p">.</span><span class="n">Close</span><span class="p">();</span> </span><span id="L-35"><a name="L-35"></a><span class="n">cryptoStream</span> <span class="p">=</span> <span class="k">null</span><span class="p">;</span> </span><span id="L-36"><a name="L-36"></a><span class="n">memStream</span> <span class="p">=</span> <span class="k">null</span><span class="p">;</span> </span><span id="L-37"><a name="L-37"></a><span class="n">encryptor</span> <span class="p">=</span> <span class="k">null</span><span class="p">;</span> </span><span id="L-38"><a name="L-38"></a><span class="n">aesAlgorithm</span> <span class="p">=</span> <span class="k">null</span><span class="p">;</span> </span></pre></div> </td></tr></table>