CSHARP-4944: Enable use of native crypto in libmongocrypt bindings (#796

)

bindings/cs/MongoDB.Libmongocrypt/CryptClientFactory.cs

@@ -15,6 +15,7 @@
  */
 
 using System;
+using System.Linq;
 
 namespace MongoDB.Libmongocrypt
 {
@@ -34,6 +35,9 @@ public class CryptClientFactory
         private static Library.Delegates.RandomCallback __randomCallback = new Library.Delegates.RandomCallback(SecureRandomCallback.GenerateRandom);
         private static Library.Delegates.CryptoHmacCallback __signRsaesPkcs1HmacCallback = new Library.Delegates.CryptoHmacCallback(SigningRSAESPKCSCallback.RsaSign);
 
+        // mongocrypt_is_crypto_available is only available in libmongocrypt version >= 1.9
+        private static readonly Version __mongocryptIsCryptoAvailableMinVersion = Version.Parse("1.9");
+
         /// <summary>Creates a CryptClient with the specified options.</summary>
         /// <param name="options">The options.</param>
         /// <returns>A CryptClient</returns>
@@ -42,14 +46,14 @@ public static CryptClient Create(CryptOptions options)
             MongoCryptSafeHandle handle = null;
             Status status = null;
 
+            var cryptoAvailable = Version.Parse(Library.Version.Split('-', '+').First()) >= __mongocryptIsCryptoAvailableMinVersion && Library.mongocrypt_is_crypto_available();
+
             try
             {
                 handle = Library.mongocrypt_new();
                 status = new Status();
-
-                // The below code can be avoided on Windows. So, we don't call it on this system 
-                // to avoid restrictions on target frameworks that present in some of below
-                if (OperatingSystemHelper.CurrentOperatingSystem != OperatingSystemPlatform.Windows)
+
+                if (!cryptoAvailable)
                 {
                     handle.Check(
                         status,

bindings/cs/MongoDB.Libmongocrypt/Library.cs

@@ -48,6 +48,9 @@ static Library()
             _mongocrypt_ctx_setopt_key_encryption_key = new Lazy<Delegates.mongocrypt_ctx_setopt_key_encryption_key>(
                 () => __loader.Value.GetFunction<Delegates.mongocrypt_ctx_setopt_key_encryption_key>(
                     ("mongocrypt_ctx_setopt_key_encryption_key")), true);
+
+            _mongocrypt_is_crypto_available = new Lazy<Delegates.mongocrypt_is_crypto_available>(
+                () => __loader.Value.GetFunction<Delegates.mongocrypt_is_crypto_available>("mongocrypt_is_crypto_available"), true);
 
             _mongocrypt_setopt_aes_256_ecb = new Lazy<Delegates.mongocrypt_setopt_aes_256_ecb>(
                 () => __loader.Value.GetFunction<Delegates.mongocrypt_setopt_aes_256_ecb>(
@@ -229,6 +232,8 @@ public static string Version
         internal static Delegates.mongocrypt_setopt_log_handler mongocrypt_setopt_log_handler => _mongocrypt_setopt_log_handler.Value;
         internal static Delegates.mongocrypt_setopt_kms_providers mongocrypt_setopt_kms_providers => _mongocrypt_setopt_kms_providers.Value;
         internal static Delegates.mongocrypt_ctx_setopt_key_encryption_key mongocrypt_ctx_setopt_key_encryption_key => _mongocrypt_ctx_setopt_key_encryption_key.Value;
+
+        internal static Delegates.mongocrypt_is_crypto_available mongocrypt_is_crypto_available => _mongocrypt_is_crypto_available.Value;
 
         internal static Delegates.mongocrypt_setopt_aes_256_ecb mongocrypt_setopt_aes_256_ecb => _mongocrypt_setopt_aes_256_ecb.Value;
         internal static Delegates.mongocrypt_setopt_bypass_query_analysis mongocrypt_setopt_bypass_query_analysis => _mongocrypt_setopt_bypass_query_analysis.Value;
@@ -306,6 +311,8 @@ public static string Version
 
         private static readonly Lazy<Delegates.mongocrypt_setopt_kms_providers> _mongocrypt_setopt_kms_providers;
         private static readonly Lazy<Delegates.mongocrypt_ctx_setopt_key_encryption_key> _mongocrypt_ctx_setopt_key_encryption_key;
+
+        private static readonly Lazy<Delegates.mongocrypt_is_crypto_available> _mongocrypt_is_crypto_available;
 
         private static readonly Lazy<Delegates.mongocrypt_setopt_aes_256_ecb> _mongocrypt_setopt_aes_256_ecb;
         private static readonly Lazy<Delegates.mongocrypt_setopt_bypass_query_analysis> _mongocrypt_setopt_bypass_query_analysis;
@@ -399,6 +406,9 @@ internal class Delegates
 
             public delegate MongoCryptSafeHandle mongocrypt_new();
 
+            [return: MarshalAs(UnmanagedType.I1)]
+            public delegate bool mongocrypt_is_crypto_available();
+
             public delegate void LogCallback([MarshalAs(UnmanagedType.I4)] LogLevel level, IntPtr messasge,
                 uint message_length, IntPtr context);
 

bindings/cs/MongoDB.Libmongocrypt/LibraryLoader.cs

@@ -28,6 +28,7 @@ namespace MongoDB.Libmongocrypt
     internal class LibraryLoader
     {
         private ISharedLibraryLoader _loader;
+        private static readonly string __libmongocryptLibPath = Environment.GetEnvironmentVariable("LIBMONGOCRYPT_PATH");
 
         public LibraryLoader()
         {
@@ -54,48 +55,21 @@ public LibraryLoader()
             switch (OperatingSystemHelper.CurrentOperatingSystem)
             {
                 case OperatingSystemPlatform.MacOS:
-                    {
-                        string[] suffixPaths = new[]
-                        {
-                            "../../runtimes/osx/native/",
-                            "runtimes/osx/native/",
-                            string.Empty
-                        };
-                        string path = FindLibrary(candidatePaths, suffixPaths, "libmongocrypt.dylib");
-                        _loader = new DarwinLibraryLoader(path);
-                    }
+                    _loader = new DarwinLibraryLoader(candidatePaths);
                     break;
                 case OperatingSystemPlatform.Linux:
-                    {
-                        string[] suffixPaths = new[]
-                        {
-                            "../../runtimes/linux/native/",
-                            "runtimes/linux/native/",
-                            string.Empty
-                        };
-                        string path = FindLibrary(candidatePaths, suffixPaths, "libmongocrypt.so");
-                        _loader = new LinuxLibrary(path);
-                    }
+                    _loader = new LinuxLibrary(candidatePaths);
                     break;
                 case OperatingSystemPlatform.Windows:
-                    {
-                        string[] suffixPaths = new[]
-                        {
-                            @"..\..\runtimes\win\native\",
-                            @".\runtimes\win\native\",
-                            string.Empty
-                        };
-                        string path = FindLibrary(candidatePaths, suffixPaths, "mongocrypt.dll");
-                        _loader = new WindowsLibrary(path);
-                    }
+                    _loader = new WindowsLibrary(candidatePaths);
                     break;
                 default:
                     // should not be reached. If we're here, then there is a bug in OperatingSystemHelper
                     throw new PlatformNotSupportedException("Unsupported operating system.");
             }
         }
 
-        private string FindLibrary(IList<string> basePaths, string[] suffixPaths, string library)
+        private static string FindLibrary(IList<string> basePaths, string[] suffixPaths, string library)
         {
             var candidates = new List<string>();
             foreach (var basePath in basePaths)
@@ -150,9 +124,17 @@ private class DarwinLibraryLoader : ISharedLibraryLoader
             public const int RTLD_GLOBAL = 0x8;
             public const int RTLD_NOW = 0x2;
 
+            private static readonly string[] __suffixPaths = 
+            {
+                "../../runtimes/osx/native/",
+                "runtimes/osx/native/",
+                string.Empty
+            };
+
             private readonly IntPtr _handle;
-            public DarwinLibraryLoader(string path)
+            public DarwinLibraryLoader(List<string> candidatePaths)
             {
+                var path = __libmongocryptLibPath ?? FindLibrary(candidatePaths, __suffixPaths, "libmongocrypt.dylib");
                 _handle = dlopen(path, RTLD_GLOBAL | RTLD_NOW);
                 if (_handle == IntPtr.Zero)
                 {
@@ -186,10 +168,18 @@ private class LinuxLibrary : ISharedLibraryLoader
             // #define RTLD_GLOBAL     0x100
             public const int RTLD_GLOBAL = 0x100;
             public const int RTLD_NOW = 0x2;
+
+            private static readonly string[] __suffixPaths = 
+            {
+                "../../runtimes/linux/native/",
+                "runtimes/linux/native/",
+                string.Empty
+            };
 
             private readonly IntPtr _handle;
-            public LinuxLibrary(string path)
+            public LinuxLibrary(List<string> candidatePaths)
             {
+                var path = __libmongocryptLibPath ?? FindLibrary(candidatePaths, __suffixPaths, "libmongocrypt.so");
                 _handle = dlopen(path, RTLD_GLOBAL | RTLD_NOW);
                 if (_handle == IntPtr.Zero)
                 {
@@ -216,9 +206,17 @@ public IntPtr GetFunction(string name)
         /// </summary>
         private class WindowsLibrary : ISharedLibraryLoader
         {
+            private static readonly string[] __suffixPaths = 
+            {
+                @"..\..\runtimes\win\native\",
+                @".\runtimes\win\native\",
+                string.Empty
+            };
+
             private readonly IntPtr _handle;
-            public WindowsLibrary(string path)
+            public WindowsLibrary(List<string> candidatePaths)
             {
+                var path = __libmongocryptLibPath ?? FindLibrary(candidatePaths, __suffixPaths, "mongocrypt.dll");
                 _handle = LoadLibrary(path);
                 if (_handle == IntPtr.Zero)
                 {

bindings/cs/README.md

@@ -54,6 +54,9 @@ If you see `Windows Error: 126` during tests, like the example below, it means t
 2. cd <build>/bindings/cs
 3. dotnet build cs.build
 ```
+*Note*: You can use the ```LIBMONGOCRYPT_PATH``` environment variable to load a locally installed
+libmongocrypt build. You should specify the absolute path to the libmongocrypt library itself, not just the containing folder. For example on Linux:
+```$ export LIBMONGOCRYPT_PATH='/path/to/libmongocrypt.so'```.
 
 # Testing
 Do not modify xunit.runner.json

bindings/cs/Scripts/build.cake

@@ -72,7 +72,7 @@ Task("Prepare")
             libmongocryptAllDirectory.Combine("ubuntu1804-64").Combine("nocrypto").Combine("lib").CombineWithFilePath("libmongocrypt.so"),
             downloadedMongocryptDirectory.CombineWithFilePath("libmongocrypt.so"));
         CopyFile(
-            libmongocryptAllDirectory.Combine("macos").Combine("nocrypto").Combine("lib").CombineWithFilePath("libmongocrypt.dylib"),
+            libmongocryptAllDirectory.Combine("macos").Combine("lib").CombineWithFilePath("libmongocrypt.dylib"),
             downloadedMongocryptDirectory.CombineWithFilePath("libmongocrypt.dylib"));
         CopyDirectory(downloadedMongocryptDirectory, libmongocryptRelWithDebInfoDirectory);
     });