feat: add base Rsa encryption class with method for data encryption and decryption including method to generate keys

Author: selfmadecode

src/SafeCrypt.Lib/Encryption/RsaEncryption/RsaEncryption.cs

@@ -0,0 +1,65 @@
+using System.Security.Cryptography;
+using System.Text;
+using System;
+using System.Threading.Tasks;
+
+namespace SafeCrypt.RsaEncryption
+{
+    public class RsaEncryption
+    {
+        /// <summary>
+        /// Generates RSA key pair.
+        /// </summary>
+        /// <param name="keySize">The size of the key pair (e.g., 1024, 2048 bits).</param>
+        /// <returns>The generated RSA key pair.</returns>
+        public static Tuple<string, string> GenerateRsaKeys(int keySize)
+        {
+            using (var rsa = new RSACryptoServiceProvider(keySize))
+            {
+                string publicKey = rsa.ToXmlString(false); // Don't include private key
+                string privateKey = rsa.ToXmlString(true); // Include private key
+
+                return new Tuple<string, string>(publicKey, privateKey);
+            }
+        }
+
+        /// <summary>
+        /// Encrypts data using RSA public key.
+        /// </summary>
+        /// <param name="data">The data to be encrypted.</param>
+        /// <param name="publicKey">The RSA public key.</param>
+        /// <returns>The encrypted data.</returns>
+        public static async Task<byte[]> EncryptAsync(string data, string publicKey)
+        {
+
+            return await Task.Run(() => {
+                using (var rsa = new RSACryptoServiceProvider())
+                {
+                    rsa.FromXmlString(publicKey);
+                    byte[] dataBytes = Encoding.UTF8.GetBytes(data);
+                    byte[] encryptedData = rsa.Encrypt(dataBytes, false);
+                    return encryptedData;
+                }
+            });
+        }
+
+        /// <summary>
+        /// Decrypts data using RSA private key.
+        /// </summary>
+        /// <param name="encryptedData">The encrypted data.</param>
+        /// <param name="privateKey">The RSA private key.</param>
+        /// <returns>The decrypted data.</returns>
+        public static async Task<string> DecryptAsync(byte[] encryptedData, string privateKey)
+        {
+            return await Task.Run(() =>
+            {
+                using (var rsa = new RSACryptoServiceProvider())
+                {
+                    rsa.FromXmlString(privateKey);
+                    byte[] decryptedData = rsa.Decrypt(encryptedData, false);
+                    return Encoding.UTF8.GetString(decryptedData);
+                }
+            });
+        }
+    }
+}