crypto function service

src/Core/Abstractions/ICryptoFunctionService.cs

@@ -0,0 +1,10 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Bit.Core.Abstractions
+{
+    public interface ICryptoFunctionService
+    {
+    }
+}

src/Core/Abstractions/ICryptoPrimitiveService.cs

@@ -0,0 +1,9 @@
+using Bit.Core.Enums;
+
+namespace Bit.Core.Abstractions
+{
+    public interface ICryptoPrimitiveService
+    {
+        byte[] Pbkdf2(byte[] password, byte[] salt, CryptoHashAlgorithm algorithm, int iterations);
+    }
+}

src/Core/Core.csproj

@@ -14,6 +14,7 @@
   <ItemGroup>
     <PackageReference Include="LiteDB" Version="4.1.4" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.1" />
+    <PackageReference Include="PCLCrypto" Version="2.0.147" />
     <PackageReference Include="Xamarin.Essentials" Version="1.1.0" />
   </ItemGroup>
 

src/Core/Enums/CryptoHashAlgorithm.cs

@@ -0,0 +1,10 @@
+namespace Bit.Core.Enums
+{
+    public enum CryptoHashAlgorithm
+    {
+        Sha1 = 0,
+        Sha256 = 1,
+        Sha512 = 2,
+        Md5 = 3
+    }
+}

src/Core/Services/PclCryptoFunctionService.cs

@@ -0,0 +1,162 @@
+using Bit.Core.Abstractions;
+using Bit.Core.Enums;
+using PCLCrypto;
+using System;
+using System.Text;
+using System.Threading.Tasks;
+using static PCLCrypto.WinRTCrypto;
+
+namespace Bit.Core.Services
+{
+    public class PclCryptoFunctionService
+    {
+        private readonly ICryptoPrimitiveService _cryptoPrimitiveService;
+
+        public PclCryptoFunctionService(ICryptoPrimitiveService cryptoPrimitiveService)
+        {
+            _cryptoPrimitiveService = cryptoPrimitiveService;
+        }
+
+        public Task<byte[]> Pbkdf2Async(string password, string salt, CryptoHashAlgorithm algorithm, int iterations)
+        {
+            return Pbkdf2Async(Encoding.UTF8.GetBytes(password), Encoding.UTF8.GetBytes(salt), algorithm, iterations);
+        }
+
+        public Task<byte[]> Pbkdf2Async(byte[] password, string salt, CryptoHashAlgorithm algorithm, int iterations)
+        {
+            return Pbkdf2Async(password, Encoding.UTF8.GetBytes(salt), algorithm, iterations);
+        }
+
+        public Task<byte[]> Pbkdf2Async(string password, byte[] salt, CryptoHashAlgorithm algorithm, int iterations)
+        {
+            return Pbkdf2Async(Encoding.UTF8.GetBytes(password), salt, algorithm, iterations);
+        }
+
+        public Task<byte[]> Pbkdf2Async(byte[] password, byte[] salt, CryptoHashAlgorithm algorithm, int iterations)
+        {
+            if(algorithm != CryptoHashAlgorithm.Sha256 && algorithm != CryptoHashAlgorithm.Sha512)
+            {
+                throw new ArgumentException("Unsupported PBKDF2 algorithm.");
+            }
+            return Task.FromResult(_cryptoPrimitiveService.Pbkdf2(password, salt, algorithm, iterations));
+        }
+
+        public Task<byte[]> HashAsync(string value, CryptoHashAlgorithm algorithm)
+        {
+            return HashAsync(Encoding.UTF8.GetBytes(value), algorithm);
+        }
+
+        public Task<byte[]> HashAsync(byte[] value, CryptoHashAlgorithm algorithm)
+        {
+            var provider = HashAlgorithmProvider.OpenAlgorithm(ToHashAlgorithm(algorithm));
+            return Task.FromResult(provider.HashData(value));
+        }
+
+        public Task<byte[]> HmacAsync(byte[] value, byte[] key, CryptoHashAlgorithm algorithm)
+        {
+            var provider = MacAlgorithmProvider.OpenAlgorithm(ToMacAlgorithm(algorithm));
+            var hasher = provider.CreateHash(key);
+            hasher.Append(value);
+            return Task.FromResult(hasher.GetValueAndReset());
+        }
+
+        public Task<byte[]> AesEncryptAsync(byte[] data, byte[] iv, byte[] key)
+        {
+            var provider = SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
+            var cryptoKey = provider.CreateSymmetricKey(key);
+            return Task.FromResult(CryptographicEngine.Encrypt(cryptoKey, data, iv));
+        }
+
+        public Task<byte[]> AesDecryptAsync(byte[] data, byte[] iv, byte[] key)
+        {
+            var provider = SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
+            var cryptoKey = provider.CreateSymmetricKey(key);
+            return Task.FromResult(CryptographicEngine.Decrypt(cryptoKey, data, iv));
+        }
+
+        public Task<byte[]> RsaEncryptAsync(byte[] data, byte[] publicKey, CryptoHashAlgorithm algorithm)
+        {
+            var provider = AsymmetricKeyAlgorithmProvider.OpenAlgorithm(ToAsymmetricAlgorithm(algorithm));
+            var cryptoKey = provider.ImportPublicKey(publicKey,
+                CryptographicPublicKeyBlobType.X509SubjectPublicKeyInfo);
+            return Task.FromResult(CryptographicEngine.Encrypt(cryptoKey, data));
+        }
+
+        public Task<byte[]> RsaDecryptAsync(byte[] data, byte[] privateKey, CryptoHashAlgorithm algorithm)
+        {
+            var provider = AsymmetricKeyAlgorithmProvider.OpenAlgorithm(ToAsymmetricAlgorithm(algorithm));
+            var cryptoKey = provider.ImportKeyPair(privateKey, CryptographicPrivateKeyBlobType.Pkcs8RawPrivateKeyInfo);
+            return Task.FromResult(CryptographicEngine.Decrypt(cryptoKey, data));
+        }
+
+        public Task<byte[]> RsaExtractPublicKeyAsync(byte[] privateKey)
+        {
+            // Have to specify some algorithm
+            var provider = AsymmetricKeyAlgorithmProvider.OpenAlgorithm(AsymmetricAlgorithm.RsaOaepSha1);
+            var cryptoKey = provider.ImportKeyPair(privateKey, CryptographicPrivateKeyBlobType.Pkcs8RawPrivateKeyInfo);
+            return Task.FromResult(cryptoKey.ExportPublicKey(CryptographicPublicKeyBlobType.X509SubjectPublicKeyInfo));
+        }
+
+        public Task<Tuple<byte[], byte[]>> RsaGenerateKeyPairAsync(int length)
+        {
+            // Have to specify some algorithm
+            var provider = AsymmetricKeyAlgorithmProvider.OpenAlgorithm(AsymmetricAlgorithm.RsaOaepSha1);
+            var cryptoKey = provider.CreateKeyPair(length);
+            var publicKey = cryptoKey.ExportPublicKey(CryptographicPublicKeyBlobType.X509SubjectPublicKeyInfo);
+            var privateKey = cryptoKey.Export(CryptographicPrivateKeyBlobType.Pkcs8RawPrivateKeyInfo);
+            return Task.FromResult(new Tuple<byte[], byte[]>(publicKey, privateKey));
+        }
+
+        public Task<byte[]> RandomBytesAsync(int length)
+        {
+            return Task.FromResult(CryptographicBuffer.GenerateRandom(length));
+        }
+
+        private HashAlgorithm ToHashAlgorithm(CryptoHashAlgorithm algorithm)
+        {
+            switch(algorithm)
+            {
+                case CryptoHashAlgorithm.Sha1:
+                    return HashAlgorithm.Sha1;
+                case CryptoHashAlgorithm.Sha256:
+                    return HashAlgorithm.Sha256;
+                case CryptoHashAlgorithm.Sha512:
+                    return HashAlgorithm.Sha512;
+                case CryptoHashAlgorithm.Md5:
+                    return HashAlgorithm.Md5;
+                default:
+                    throw new ArgumentException("Unsupported hash algorithm.");
+            }
+        }
+
+        private MacAlgorithm ToMacAlgorithm(CryptoHashAlgorithm algorithm)
+        {
+            switch(algorithm)
+            {
+                case CryptoHashAlgorithm.Sha1:
+                    return MacAlgorithm.HmacSha1;
+                case CryptoHashAlgorithm.Sha256:
+                    return MacAlgorithm.HmacSha256;
+                case CryptoHashAlgorithm.Sha512:
+                    return MacAlgorithm.HmacSha512;
+                default:
+                    throw new ArgumentException("Unsupported mac algorithm.");
+            }
+        }
+
+        private AsymmetricAlgorithm ToAsymmetricAlgorithm(CryptoHashAlgorithm algorithm)
+        {
+            switch(algorithm)
+            {
+                case CryptoHashAlgorithm.Sha1:
+                    return AsymmetricAlgorithm.RsaOaepSha1;
+                // RsaOaepSha256 is not supported on iOS
+                // ref: https://github.com/AArnott/PCLCrypto/issues/124
+                // case CryptoHashAlgorithm.SHA256:
+                //    return AsymmetricAlgorithm.RsaOaepSha256;
+                default:
+                    throw new ArgumentException("Unsupported asymmetric algorithm.");
+            }
+        }
+    }
+}