Here I am storing the values in database using LINQ queries as encrypted form.

We can encrypt or decrypt values using other algorithms.

But here, I am using SALT to encrypt and decrypt the values.

Step 1:

  1. public byte[] AES_Encrypt(byte[] bytesToBeEncrypted, byte[] passwordBytes)
  2. {
  3. byte[] encryptedBytes = null;
  5. // Set your salt here, change it to meet your flavor:
  6. byte[] saltBytes = passwordBytes;
  7. // Example:
  8. //saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };
  10. using (MemoryStream ms = new MemoryStream())
  11. {
  12. using (RijndaelManaged AES = new RijndaelManaged())
  13. {
  14. AES.KeySize = 256;
  15. AES.BlockSize = 128;
  17. var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000);
  18. AES.Key = key.GetBytes(AES.KeySize / 8);
  19. AES.IV = key.GetBytes(AES.BlockSize / 8);
  21. AES.Mode = CipherMode.CBC;
  23. using (CryptoStream cs = new CryptoStream(ms, AES.CreateEncryptor(), CryptoStreamMode.Write))
  24. {
  25. cs.Write(bytesToBeEncrypted, 0, bytesToBeEncrypted.Length);
  26. cs.Close();
  27. }
  28. encryptedBytes = ms.ToArray();
  29. }
  30. }
  32. return encryptedBytes;
  33. }
  34. public byte[] AES_Decrypt(byte[] bytesToBeDecrypted, byte[] passwordBytes)
  35. {
  36. try
  37. {
  38. byte[] decryptedBytes = null;
  39. // Set your salt here to meet your flavor:
  40. byte[] saltBytes = passwordBytes;
  41. // Example:
  42. //saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };
  44. using (MemoryStream ms = new MemoryStream())
  45. {
  46. using (RijndaelManaged AES = new RijndaelManaged())
  47. {
  48. AES.KeySize = 256;
  49. AES.BlockSize = 128;
  51. var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000);
  52. AES.Key = key.GetBytes(AES.KeySize / 8);
  53. AES.IV = key.GetBytes(AES.BlockSize / 8);
  55. //AES.Mode = CipherMode.CBC;
  57. using (CryptoStream cs = new CryptoStream(ms, AES.CreateDecryptor(), CryptoStreamMode.Write))
  58. {
  59. cs.Write(bytesToBeDecrypted, 0, bytesToBeDecrypted.Length);
  60. //If(cs.Length = ""
  61. cs.Close();
  62. }
  63. decryptedBytes = ms.ToArray();
  64. }
  65. }
  66. return decryptedBytes;
  67. }
  68. catch (Exception Ex)
  69. {
  70. return null;
  71. }
  72. }
  73. public string Encrypt(string text, string pwd)
  74. {
  75. byte[] originalBytes = Encoding.UTF8.GetBytes(text);
  76. byte[] encryptedBytes = null;
  77. byte[] passwordBytes = Encoding.UTF8.GetBytes(pwd);
  79. // Hash the password with SHA256
  80. passwordBytes = SHA256.Create().ComputeHash(passwordBytes);
  82. // Getting the salt size
  83. int saltSize = GetSaltSize(passwordBytes);
  84. // Generating salt bytes
  85. byte[] saltBytes = GetRandomBytes(saltSize);
  87. // Appending salt bytes to original bytes
  88. byte[] bytesToBeEncrypted = new byte[saltBytes.Length + originalBytes.Length];
  89. for (int i = 0; i < saltBytes.Length; i++)
  90. {
  91. bytesToBeEncrypted[i] = saltBytes[i];
  92. }
  93. for (int i = 0; i < originalBytes.Length; i++)
  94. {
  95. bytesToBeEncrypted[i + saltBytes.Length] = originalBytes[i];
  96. }
  98. encryptedBytes = AES_Encrypt(bytesToBeEncrypted, passwordBytes);
  100. return Convert.ToBase64String(encryptedBytes);
  101. }
  102. public string Decrypt(string decryptedText, string pwd)
  103. {
  104. byte[] bytesToBeDecrypted = Convert.FromBase64String(decryptedText);
  105. byte[] passwordBytes = Encoding.UTF8.GetBytes(pwd);
  107. // Hash the password with SHA256
  108. passwordBytes = SHA256.Create().ComputeHash(passwordBytes);
  110. byte[] decryptedBytes = AES_Decrypt(bytesToBeDecrypted, passwordBytes);
  112. if (decryptedBytes != null)
  113. {
  114. // Getting the size of salt
  115. int saltSize = GetSaltSize(passwordBytes);
  117. // Removing salt bytes, retrieving original bytes
  118. byte[] originalBytes = new byte[decryptedBytes.Length - saltSize];
  119. for (int i = saltSize; i < decryptedBytes.Length; i++)
  120. {
  121. originalBytes[i - saltSize] = decryptedBytes[i];
  122. }
  123. return Encoding.UTF8.GetString(originalBytes);
  124. }
  125. else
  126. {
  127. return null;
  128. }
  129. }
  130. private int GetSaltSize(byte[] passwordBytes)
  131. {
  132. var key = new Rfc2898DeriveBytes(passwordBytes, passwordBytes, 1000);
  133. byte[] ba = key.GetBytes(2);
  134. StringBuilder sb = new StringBuilder();
  135. for (int i = 0; i < ba.Length; i++)
  136. {
  137. sb.Append(Convert.ToInt32(ba[i]).ToString());
  138. }
  139. int saltSize = 0;
  140. string s = sb.ToString();
  141. foreach (char c in s)
  142. {
  143. int intc = Convert.ToInt32(c.ToString());
  144. saltSize = saltSize + intc;
  145. }
  147. return saltSize;
  148. }
  149. public byte[] GetRandomBytes(int length)
  150. {
  151. byte[] ba = new byte[length];
  152. RNGCryptoServiceProvider.Create().GetBytes(ba);
  153. return ba;
  154. }
  156. public bool Add(Movy movie)
  157. {
  158. demo.Movies.InsertOnSubmit(movie);
  159. demo.SubmitChanges();
  160. return true;
  161. }
Step 2: Call that methods in .cs file.
  1. public partial class Add: System.Web.UI.Page
  2. {
  3. /// <summary>
  4. /// Linq To SQL : Connection object.
  5. /// </summary>
  6. DemoDataContext demo = new DemoDataContext();
  8. protected void Page_Load(object sender, EventArgs e)
  9. {
  11. }
  13. /// <summary>
  14. /// Button submit click event : Storing value in database as encrypted form
  15. /// </summary>
  16. /// <param name="sender"></param>
  17. /// <param name="e"></param>
  18. protected void btnSubmit_Click(object sender, EventArgs e) {
  19. try {
  20. if (txtName.Text != "")
  21. {
  22. var m = new Movy
  23. {
  24. MovieName = new SecurityClass().Encrypt(txtName.Text, txtName.Text),
  25. };
  26. new SecurityClass().Add(m);
  27. lblMessgae.Text = "Submitted successfully.";
  28. txtName.Text = "";
  29. }
  30. }
  31. catch (Exception ex)
  32. {
  33. ex.Message.ToString();
  34. }
  35. }
  37. protected void btnSearch_Click(object sender, EventArgs e) {
  38. try {
  39. if (txtSearchByName.Text != "")
  40. {
  41. var movienameEncrypted = new SecurityClass().Encrypt(txtName.Text, txtName.Text);
  42. if (movienameEncrypted != null)
  43. {
  44. string movienameDecrypt = new SecurityClass().Decrypt(movienameEncrypted, txtSearchByName.Text);
  45. if (movienameDecrypt != null)
  46. {
  47. var Details = (from m in demo.Movies where movienameDecrypt == txtSearchByName.Text select new
  48. {
  49. UserName = m.Id
  50. })
  51. .FirstOrDefault();
  52. if (Details != null)
  53. {
  54. lblMessgae.Text = "Movie exist into the database.";
  55. }
  56. else
  57. {
  58. lblMessgae.Text = "Not exist.";
  59. }
  60. }
  61. else
  62. {
  63. lblMessgae.Text = "Not exist.";
  64. }
  65. }
  66. }
  67. }
  68. catch (Exception ex)
  69. {
  70. ex.Message.ToString();
  71. }
  72. }
Screen:

output