crypto function service

src/Android/Services/CryptoPrimitiveService.cs

@@ -0,0 +1,37 @@
+using Bit.Core.Abstractions;
+using Bit.Core.Enums;
+using Org.BouncyCastle.Crypto;
+using Org.BouncyCastle.Crypto.Digests;
+using Org.BouncyCastle.Crypto.Generators;
+using Org.BouncyCastle.Crypto.Parameters;
+using System;
+
+namespace Bit.Droid.Services
+{
+    public class CryptoPrimitiveService : ICryptoPrimitiveService
+    {
+        public byte[] Pbkdf2(byte[] password, byte[] salt, CryptoHashAlgorithm algorithm, int iterations)
+        {
+            int keySize = 256;
+            IDigest digest = null;
+            if(algorithm == CryptoHashAlgorithm.Sha256)
+            {
+                keySize = 256;
+                digest = new Sha256Digest();
+            }
+            else if(algorithm == CryptoHashAlgorithm.Sha512)
+            {
+                keySize = 512;
+                digest = new Sha512Digest();
+            }
+            else
+            {
+                throw new ArgumentException("Unsupported PBKDF2 algorithm.");
+            }
+
+            var generator = new Pkcs5S2ParametersGenerator(digest);
+            generator.Init(password, salt, iterations);
+            return ((KeyParameter)generator.GenerateDerivedMacParameters(keySize)).GetKey();
+        }
+    }
+}