OPC # 0001: Extract Clarity into standalone repo
This commit is contained in:
amadzarak
@@ -0,0 +1,272 @@
|
||||
using Microsoft.EntityFrameworkCore;
|
||||
using Microsoft.EntityFrameworkCore.Diagnostics;
|
||||
using System.Security.Cryptography;
|
||||
using System.Text;
|
||||
using System.Text.Json.Serialization;
|
||||
using VaultSharp;
|
||||
using VaultSharp.V1.SecretsEngines;
|
||||
using VaultSharp.V1.SecretsEngines.Transit;
|
||||
using VaultSharp.V1.Commons;
|
||||
using System.Collections.Generic;
|
||||
|
||||
namespace Clarity.Server.Data;
|
||||
|
||||
public interface IPIIEntity
|
||||
{
|
||||
public byte[] EncryptedDek { get; set; }
|
||||
public string Tenant { get; set; }
|
||||
}
|
||||
|
||||
public interface IPIIVault
|
||||
{
|
||||
Task<(byte[] PlaintextKey, string CiphertextKey)> GenerateTenantKEKAsync(string tenantId);
|
||||
Task<byte[]> DecryptTenantKEKAsync(string encryptedKek, string tenantId);
|
||||
Task<string> RewrapTenantKEKAsync(string encryptedKek, string tenantId);
|
||||
}
|
||||
|
||||
|
||||
public class TenantKeyProvider
|
||||
{
|
||||
public byte[]? CurrentKey { get; private set; }
|
||||
public void SetKey(byte[] key) => CurrentKey = key;
|
||||
}
|
||||
|
||||
public class PIIVault : IPIIVault
|
||||
{
|
||||
private readonly IVaultClient _vaultClient;
|
||||
|
||||
private const string TransitPath = "clarity-transit";
|
||||
private const string MasterKeyName = "master-key";
|
||||
|
||||
public PIIVault(IVaultClient vaultClient)
|
||||
{
|
||||
_vaultClient = vaultClient;
|
||||
}
|
||||
|
||||
// https://github.com/rajanadar/VaultSharp/blob/master/test/VaultSharp.Samples/Backends/Secrets/TransitSecretsBackendSamples.cs
|
||||
public async Task<(byte[] PlaintextKey, string CiphertextKey)> GenerateTenantKEKAsync(string tenantId)
|
||||
{
|
||||
var encodedContext = Convert.ToBase64String(Encoding.UTF8.GetBytes(tenantId));
|
||||
var dataKeyOptions = new DataKeyRequestOptions
|
||||
{
|
||||
DataKeyType = TransitDataKeyType.plaintext,
|
||||
Base64EncodedContext = encodedContext
|
||||
};
|
||||
|
||||
Secret<DataKeyResponse> response = await _vaultClient.V1.Secrets.Transit.GenerateDataKeyAsync(
|
||||
MasterKeyName,
|
||||
dataKeyOptions,
|
||||
TransitPath);
|
||||
|
||||
byte[] rawPlaintextBytes = Convert.FromBase64String(response.Data.Base64EncodedPlainText);
|
||||
string ciphertext = response.Data.CipherText;
|
||||
|
||||
return (rawPlaintextBytes, ciphertext);
|
||||
}
|
||||
|
||||
public async Task<byte[]> DecryptTenantKEKAsync(string encryptedKek, string tenantId)
|
||||
{
|
||||
var encodedContext = Convert.ToBase64String(Encoding.UTF8.GetBytes(tenantId));
|
||||
var decryptOptions = new DecryptRequestOptions
|
||||
{
|
||||
CipherText = encryptedKek,
|
||||
Base64EncodedContext = encodedContext
|
||||
};
|
||||
|
||||
Secret<DecryptionResponse> response = await _vaultClient.V1.Secrets.Transit.DecryptAsync(
|
||||
MasterKeyName,
|
||||
decryptOptions,
|
||||
TransitPath);
|
||||
|
||||
return Convert.FromBase64String(response.Data.Base64EncodedPlainText);
|
||||
}
|
||||
|
||||
public async Task<string> RewrapTenantKEKAsync(string encryptedKek, string tenantId)
|
||||
{
|
||||
var encodedContext = Convert.ToBase64String(Encoding.UTF8.GetBytes(tenantId));
|
||||
|
||||
var rewrapOptions = new RewrapRequestOptions
|
||||
{
|
||||
CipherText = encryptedKek,
|
||||
Base64EncodedContext = encodedContext
|
||||
};
|
||||
|
||||
var response = await _vaultClient.V1.Secrets.Transit.RewrapAsync(
|
||||
MasterKeyName,
|
||||
rewrapOptions,
|
||||
TransitPath);
|
||||
|
||||
return response.Data.CipherText;
|
||||
}
|
||||
}
|
||||
public static class TenantSecurityExtensions
|
||||
{
|
||||
public static async Task InitializeTenantSecurityAsync(this WebApplication app)
|
||||
{
|
||||
using var scope = app.Services.CreateScope();
|
||||
var db = scope.ServiceProvider.GetRequiredService<ApplicationDbContext>();
|
||||
var piiVault = scope.ServiceProvider.GetRequiredService<IPIIVault>();
|
||||
var keyProvider = scope.ServiceProvider.GetRequiredService<TenantKeyProvider>();
|
||||
|
||||
var tenantId = app.Configuration["Tenant__Id"] ?? "CLARITY_01000000";
|
||||
|
||||
var settings = await db.SysParams.FirstOrDefaultAsync();
|
||||
|
||||
if (settings == null)
|
||||
{
|
||||
// Generate the key!
|
||||
var (plaintext, ciphertext) = await piiVault.GenerateTenantKEKAsync(tenantId);
|
||||
|
||||
// Save ciphertext to DB so we have it for the next restart
|
||||
db.SysParams.Add(new SysParams { EncryptedKek = ciphertext });
|
||||
await db.SaveChangesAsync();
|
||||
|
||||
// Store plaintext in RAM
|
||||
keyProvider.SetKey(plaintext);
|
||||
}
|
||||
else
|
||||
{
|
||||
// Ask Vault to unwrap the existing key using the Master Key + Context
|
||||
var plaintext = await piiVault.DecryptTenantKEKAsync(settings.EncryptedKek, tenantId);
|
||||
|
||||
// Store plaintext back in RAM
|
||||
keyProvider.SetKey(plaintext);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
[AttributeUsage(AttributeTargets.Property)]
|
||||
public class PiiDataAttribute : Attribute
|
||||
{
|
||||
|
||||
}
|
||||
|
||||
|
||||
public class EnvelopeEncryptionInterceptor : SaveChangesInterceptor, IMaterializationInterceptor
|
||||
{
|
||||
private readonly TenantKeyProvider _keyProvider;
|
||||
|
||||
public EnvelopeEncryptionInterceptor(TenantKeyProvider keyProvider)
|
||||
{
|
||||
_keyProvider = keyProvider;
|
||||
}
|
||||
|
||||
public override InterceptionResult<int> SavingChanges(DbContextEventData eventData, InterceptionResult<int> result)
|
||||
{
|
||||
EncryptEntities(eventData.Context);
|
||||
return base.SavingChanges(eventData, result);
|
||||
}
|
||||
|
||||
public override ValueTask<InterceptionResult<int>> SavingChangesAsync(DbContextEventData eventData, InterceptionResult<int> result, CancellationToken cancellationToken = default)
|
||||
{
|
||||
EncryptEntities(eventData.Context);
|
||||
return base.SavingChangesAsync(eventData, result, cancellationToken);
|
||||
}
|
||||
|
||||
public object InitializedInstance(MaterializationInterceptionData materializationData, object entity)
|
||||
{
|
||||
if (entity is not IPIIEntity piiEntity || _keyProvider.CurrentKey == null || piiEntity.EncryptedDek == null)
|
||||
{
|
||||
return entity;
|
||||
}
|
||||
|
||||
try
|
||||
{
|
||||
// 1. Open the Envelope (Unwrap Row DEK)
|
||||
byte[] rowDek = AesGcmHelper.Decrypt(piiEntity.EncryptedDek, _keyProvider.CurrentKey);
|
||||
|
||||
var props = entity.GetType().GetProperties()
|
||||
.Where(p => p.PropertyType == typeof(string) && Attribute.IsDefined(p, typeof(PiiDataAttribute)));
|
||||
|
||||
foreach (var prop in props)
|
||||
{
|
||||
var cipherText = (string?)prop.GetValue(entity);
|
||||
if (!string.IsNullOrEmpty(cipherText))
|
||||
{
|
||||
prop.SetValue(entity, AesGcmHelper.DecryptString(cipherText, rowDek));
|
||||
}
|
||||
}
|
||||
}
|
||||
catch (CryptographicException) { /* Log unauthorized tampering! */ }
|
||||
|
||||
return entity;
|
||||
}
|
||||
|
||||
private void EncryptEntities(DbContext? context)
|
||||
{
|
||||
if (context == null || _keyProvider.CurrentKey == null) return;
|
||||
|
||||
var entries = context.ChangeTracker.Entries<IPIIEntity>()
|
||||
.Where(e => e.State == EntityState.Added || e.State == EntityState.Modified);
|
||||
|
||||
foreach (var entry in entries)
|
||||
{
|
||||
var entity = entry.Entity;
|
||||
byte[] rowDek = RandomNumberGenerator.GetBytes(32);
|
||||
|
||||
// 2. Wrap the Row DEK
|
||||
entity.EncryptedDek = AesGcmHelper.Encrypt(rowDek, _keyProvider.CurrentKey);
|
||||
|
||||
var props = entity.GetType().GetProperties()
|
||||
.Where(p => p.PropertyType == typeof(string) && Attribute.IsDefined(p, typeof(PiiDataAttribute)));
|
||||
|
||||
foreach (var prop in props)
|
||||
{
|
||||
var plainText = (string?)prop.GetValue(entity);
|
||||
if (!string.IsNullOrEmpty(plainText))
|
||||
{
|
||||
prop.SetValue(entity, AesGcmHelper.EncryptString(plainText, rowDek));
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// AES-GCM High-Performance Helper
|
||||
/// Uses Span<byte> for speed, but returns byte[] for EF Core storage.
|
||||
/// </summary>
|
||||
public static class AesGcmHelper
|
||||
{
|
||||
private const int NonceSize = 12; // AesGcm.NonceByteSizes.MaxSize
|
||||
private const int TagSize = 16; // AesGcm.TagByteSizes.MaxSize
|
||||
|
||||
public static byte[] Encrypt(ReadOnlySpan<byte> data, ReadOnlySpan<byte> key)
|
||||
{
|
||||
// Final buffer: [Nonce (12)] [Tag (16)] [Ciphertext (N)]
|
||||
byte[] result = new byte[NonceSize + TagSize + data.Length];
|
||||
|
||||
Span<byte> nonce = result.AsSpan(0, NonceSize);
|
||||
Span<byte> tag = result.AsSpan(NonceSize, TagSize);
|
||||
Span<byte> cipher = result.AsSpan(NonceSize + TagSize);
|
||||
|
||||
RandomNumberGenerator.Fill(nonce);
|
||||
|
||||
using var aes = new AesGcm(key);
|
||||
aes.Encrypt(nonce, data, cipher, tag);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
public static byte[] Decrypt(ReadOnlySpan<byte> encryptedData, ReadOnlySpan<byte> key)
|
||||
{
|
||||
if (encryptedData.Length < NonceSize + TagSize)
|
||||
throw new CryptographicException("Ciphertext too short.");
|
||||
|
||||
ReadOnlySpan<byte> nonce = encryptedData.Slice(0, NonceSize);
|
||||
ReadOnlySpan<byte> tag = encryptedData.Slice(NonceSize, TagSize);
|
||||
ReadOnlySpan<byte> cipher = encryptedData.Slice(NonceSize + TagSize);
|
||||
|
||||
byte[] result = new byte[cipher.Length];
|
||||
using var aes = new AesGcm(key);
|
||||
aes.Decrypt(nonce, cipher, tag, result);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
public static string EncryptString(string text, byte[] key) =>
|
||||
Convert.ToBase64String(Encrypt(System.Text.Encoding.UTF8.GetBytes(text), key));
|
||||
|
||||
public static string DecryptString(string cipher, byte[] key) =>
|
||||
System.Text.Encoding.UTF8.GetString(Decrypt(Convert.FromBase64String(cipher), key));
|
||||
}
|
||||
Reference in New Issue
Block a user