Allow direct encryption of binary blobs

Rijndael256.Tests/RijndaelEtMTests.cs

@@ -142,5 +142,16 @@ public void GenerateAeKeyRing()
             Assert.Equal(keyRing.CipherKey, AeKeyRingProof.CipherKey);
             Assert.True(keyRing.MacKey.SequenceEqual(AeKeyRingProof.MacKey));
         }
+
+        [Fact]
+        public void BinaryBlob()
+        {
+            var plainblob = UTF8Encoding.UTF8.GetBytes(Plaintext);
+
+            var cipherblob = RijndaelEtM.EncryptBinary(plainblob, Password, KeySize.Aes128);
+            var plainresult = RijndaelEtM.DecryptBinary(cipherblob, Password, KeySize.Aes128);
+
+            Assert.Equal(plainblob, plainresult);
+        }
     }
 }

Rijndael256.Tests/RijndaelTests.cs

@@ -98,5 +98,16 @@ public void RandomIv256()
             Assert.Equal(plaintext, Plaintext);
             Assert.NotEqual(ciphertext1, ciphertext2);
         }
+
+        [Fact]
+        public void BinaryBlob()
+        {
+            var plainblob = UTF8Encoding.UTF8.GetBytes(Plaintext);
+
+            var cipherblob = Rijndael.EncryptBinary(plainblob, Password, KeySize.Aes128);
+            var plainresult = Rijndael.DecryptBinary(cipherblob, Password, KeySize.Aes128);
+
+            Assert.Equal(plainblob, plainresult);
+        }
     }
 }

Rijndael256/Rijndael.cs

@@ -54,6 +54,26 @@ public static string Encrypt(byte[] plaintext, string password, KeySize keySize)
             return Convert.ToBase64String(ciphertext);
         }
 
+        /// <summary>
+        /// Encrypts plaintext using the Rijndael cipher in CBC mode with a password derived HMAC SHA-512 salt.
+        /// A random 128-bit Initialization Vector is generated for the cipher.
+        /// </summary>
+        /// <param name="plaintext">The plaintext to encrypt.</param>
+        /// <param name="password">The password to encrypt the plaintext with.</param>
+        /// <param name="keySize">The cipher key size. 256-bit is stronger, but slower.</param>
+        /// <returns>The encoded ciphertext.</returns>
+        public static byte[] EncryptBinary(byte[] plaintext, string password, KeySize keySize)
+        {
+            // Generate a random IV
+            var iv = Rng.GenerateRandomBytes(InitializationVectorSize);
+
+            // Encrypt the plaintext
+            var ciphertext = Encrypt(plaintext, password, iv, keySize);
+
+            // Encode the ciphertext
+            return ciphertext;
+        }
+
         /// <summary>
         /// Encrypts plaintext using the Rijndael cipher in CBC mode with a password derived HMAC SHA-512 salt.
         /// </summary>
@@ -142,6 +162,34 @@ public static string Decrypt(string ciphertext, string password, KeySize keySize
             return Decrypt(Convert.FromBase64String(ciphertext), password, keySize);
         }
 
+        /// <summary>
+        /// Decrypts ciphertext using the Rijndael cipher in CBC mode with a password derived HMAC SHA-512 salt.
+        /// </summary>
+        /// <param name="ciphertext">The ciphertext to decrypt.</param>
+        /// <param name="password">The password to decrypt the ciphertext with.</param>
+        /// <param name="keySize">The size of the cipher key used to create the ciphertext.</param>
+        /// <returns>The plaintext.</returns>
+        public static byte[] DecryptBinary(byte[] ciphertext, string password, KeySize keySize)
+        {
+            using (var ms = new MemoryStream(ciphertext))
+            {
+                // Extract the IV from the ciphertext
+                var iv = new byte[InitializationVectorSize];
+                ms.Read(iv, 0, iv.Length);
+
+                // Create a CryptoStream to decrypt the ciphertext
+                using (var cs = new CryptoStream(ms, CreateDecryptor(password, iv, keySize), CryptoStreamMode.Read))
+                {
+                    // Decrypt the ciphertext
+                    using (var buffer = new MemoryStream())
+                    {
+                        cs.CopyTo(buffer);
+                        return buffer.ToArray();
+                    }
+                }
+            }
+        }
+
         /// <summary>
         /// Decrypts ciphertext using the Rijndael cipher in CBC mode with a password derived HMAC SHA-512 salt.
         /// </summary>

Rijndael256/RijndaelEtM.cs

@@ -54,6 +54,27 @@ public class RijndaelEtM : Rijndael
             return Convert.ToBase64String(etmCiphertext);
         }
 
+        /// <summary>
+        /// Encrypts plaintext using the Encrypt-then-MAC (EtM) mode via the Rijndael cipher in 
+        /// CBC mode with a password derived HMAC SHA-512 salt. A random 128-bit Initialization 
+        /// Vector is generated for the cipher.
+        /// </summary>
+        /// <param name="plaintext">The plaintext to encrypt.</param>
+        /// <param name="password">The password to encrypt the plaintext with.</param>
+        /// <param name="keySize">The cipher key size. 256-bit is stronger, but slower.</param>
+        /// <returns>The encoded EtM ciphertext.</returns>
+        public static new byte[] EncryptBinary(byte[] plaintext, string password, KeySize keySize)
+        {
+            // Generate a random IV
+            var iv = Rng.GenerateRandomBytes(InitializationVectorSize);
+
+            // Encrypt the plaintext
+            var etmCiphertext = Encrypt(plaintext, password, iv, keySize);
+
+            // Encode the EtM ciphertext
+            return etmCiphertext;
+        }
+
         /// <summary>
         /// Encrypts plaintext using the Encrypt-then-MAC (EtM) mode via the Rijndael cipher in 
         /// CBC mode with a password derived HMAC SHA-512 salt.
@@ -96,6 +117,41 @@ public class RijndaelEtM : Rijndael
             return Decrypt(Convert.FromBase64String(etmCiphertext), password, keySize);
         }
 
+        /// <summary>
+        /// Decrypts authenticated ciphertext using the Rijndael cipher in CBC mode with a password derived 
+        /// HMAC SHA-512 salt.
+        /// </summary>
+        /// <param name="etmCiphertext">The EtM ciphertext to decrypt.</param>
+        /// <param name="password">The password to decrypt the EtM ciphertext with.</param>
+        /// <param name="keySize">The size of the cipher key used to create the EtM ciphertext.</param>
+        /// <returns>The plaintext.</returns>
+        public static new byte[] DecryptBinary(byte[] etmCiphertext, string password, KeySize keySize)
+        {
+            // Generate AE keys
+            var keyRing = AeKeyRing.Generate(password);
+
+            // Extract the ciphertext and MAC from the EtM ciphertext
+            var mac = new byte[keyRing.MacKey.Length];
+            var ciphertext = new byte[etmCiphertext.Length - mac.Length];
+            using (var ms = new MemoryStream(etmCiphertext))
+            {
+                // Extract the ciphertext
+                ms.Read(ciphertext, 0, ciphertext.Length);
+
+                // Extract the MAC
+                ms.Read(mac, 0, mac.Length);
+            }
+
+            // Calculate the MAC from the ciphertext
+            var newMac = CalculateMac(ciphertext, keyRing.MacKey);
+
+            // Authenticate ciphertext
+            if (!mac.SequenceEqual(newMac)) throw new Exception("Authentication failed!");
+
+            // Decrypt the ciphertext
+            return Rijndael.DecryptBinary(ciphertext, keyRing.CipherKey, keySize);
+        }
+
         /// <summary>
         /// Decrypts authenticated ciphertext using the Rijndael cipher in CBC mode with a password derived 
         /// HMAC SHA-512 salt.