Adding SHA256 password encryption and password verify

MainProject/Utils/CryptoUtils.cs

@@ -6,34 +6,36 @@ using BasicDotnetTemplate.MainProject.Models.Settings;
 namespace BasicDotnetTemplate.MainProject.Utils;
 public class CryptUtils
 {
-    private readonly string secretKey;
-    private const int M = 16;
-    private const int N = 32;
+    private readonly string _secretKey;
+    private readonly string _pepper;
+    private const int _M = 16;
+    private const int _N = 32;
 
     public CryptUtils(AppSettings appSettings)
     {
-        secretKey = appSettings.EncryptionSettings?.Salt ?? String.Empty;
+        _secretKey = appSettings.EncryptionSettings?.Salt ?? String.Empty;
+        _pepper = appSettings.EncryptionSettings?.Pepper ?? String.Empty;
     }
 
     public string Decrypt(string encryptedData)
     {
         var decrypted = String.Empty;
 
-        if (String.IsNullOrEmpty(this.secretKey) || this.secretKey.Length < M)
+        if (String.IsNullOrEmpty(this._secretKey) || this._secretKey.Length < _M)
         {
             throw new ArgumentException("Unable to proceed with decryption due to invalid settings");
         }
 
-        if (!String.IsNullOrEmpty(encryptedData) && encryptedData.Length > N)
+        if (!String.IsNullOrEmpty(encryptedData) && encryptedData.Length > _N)
         {
-            var iv = encryptedData.Substring(0, M);
+            var iv = encryptedData.Substring(0, _M);
 
-            var cipherText = encryptedData.Substring(N);
+            var cipherText = encryptedData.Substring(_N);
             var fullCipher = Convert.FromBase64String(cipherText);
 
             using (var aes = Aes.Create())
             {
-                aes.Key = Encoding.UTF8.GetBytes(this.secretKey);
+                aes.Key = Encoding.UTF8.GetBytes(this._secretKey);
                 aes.IV = Encoding.UTF8.GetBytes(iv);
 
                 using (var decryptor = aes.CreateDecryptor(aes.Key, aes.IV))
@@ -55,5 +57,37 @@ public class CryptUtils
         return decrypted;
     }
 
+    public static string GenerateSalt()
+    {
+        using var rng = RandomNumberGenerator.Create();
+        var byteSalt = new byte[16];
+        rng.GetBytes(byteSalt);
+        var salt = Convert.ToBase64String(byteSalt);
+        return salt;
+    }
+
+    public string GeneratePassword(string password, string salt, int iteration)
+    {
+        string hashedPassword = password;
+        for(var i = 0; i <= iteration; i++)
+        {
+            using var sha256 = SHA256.Create();
+            var passwordSaltPepper = $"{hashedPassword}{salt}{this._pepper}";
+            var byteValue = Encoding.UTF8.GetBytes(passwordSaltPepper);
+            var byteHash = sha256.ComputeHash(byteValue);
+            hashedPassword = Convert.ToBase64String(byteHash);
+        }
+
+        return hashedPassword;
+    }
+
+    public bool VerifyPassword(string password, string salt, int iteration, string userPassword)
+    {
+        string hashedPassword = this.GeneratePassword(password, salt, iteration);
+        return hashedPassword.Equals(userPassword, StringComparison.OrdinalIgnoreCase);
+    }
+
+
+
 }