Crypto engine design enhancements and new library entry point

src/crypto.zig

@@ -6,17 +6,55 @@
 //
 
 const AES = @import("crypto/aes.zig");
+const ED25519 = @import("crypto/ed25519.zig");
+const HKDF = @import("crypto/hkdf.zig");
+const HMAC = @import("crypto/hmac.zig");
+const SHA256 = @import("crypto/sha256.zig");
+const SHA512 = @import("crypto/sha512.zig");
+const X25519= @import("crypto/x25519.zig");
 
 
-///////////////// Public functions
+///////////////// Structs
 //
 
-pub fn CryptoEngine(comptime Provider: anytype) type {
-    return struct {
-        const Self = @This();
+pub const PartialEngine = struct {
+    aes_cbc256: ? AES.CBC256_Implementation = null,
+    ed25519:    ? ED25519.Implementation    = null,
+    hkdf:       ? HKDF.Implementation       = null,
+    hmac:       ? HMAC.Implementation       = null,
+    sha256:     ? SHA256.Implementation     = null,
+    sha512:     ? SHA512.Implementation     = null,
+    x25519:     ? X25519.Implementation     = null,
+};
 
-        pub const Aes = AES.AesEngine(Provider);
+pub const Engine = struct {
+    aes_cbc256: AES.CBC256_Implementation,
+    ed25519:    ED25519.Implementation,
+    hkdf:       HKDF.Implementation,
+    hmac:       HMAC.Implementation,
+    sha256:     SHA256.Implementation,
+    sha512:     SHA512.Implementation,
+    x25519:     X25519.Implementation,
+};
+
+
+///////////////// Functions
+//
+
+// Initializes the cyrpto engine with the functions given inside Provider
+// These functions must follow the same structure as the struct returned by this
+// function and its sub-structs.
+pub fn resolveEngine(comptime provider: PartialEngine) Engine {
+    return .{
+        .aes_cbc256 = provider.aes_cbc256 orelse AES.CBC256_DefaultImplementation,
+        .ed25519    = provider.ed25519    orelse ED25519.DefaultImplementation,
+        .hkdf       = provider.hkdf       orelse HKDF.DefaultImplementation,
+        .hmac       = provider.hmac       orelse HMAC.DefaultImplementation,
+        .sha256     = provider.sha256     orelse SHA256.DefaultImplementation,
+        .sha512     = provider.sha512     orelse SHA512.DefaultImplementation,
+        .x25519     = provider.x25519     orelse X25519.DefaultImplementation,
     };
+
 }
 
 
@@ -27,7 +65,7 @@ const std = @import("std");
 
 test "AES encryption defaults" {
     
-    const crypto = CryptoEngine();
+    const crypto = resolveEngine(.{});
 
     var data = [_]u8{ 1, 2, 3, 4 };
     const key = [_]u8{ 1, 2, 3, 4 };