added case for Linux

Author: CryptoSax

Package.swift

@@ -3,6 +3,7 @@
 
 import PackageDescription
 
+#if os(iOS) || os(macOS) || os(watchOS) || os(tvOS)
 let package = Package(
     name: "Keychain",
     platforms: [.macOS(.v10_15)],
@@ -32,3 +33,35 @@ let package = Package(
     ],
     swiftLanguageVersions: [.v5]
 )
+#else
+let package = Package(
+    name: "Keychain",
+    products: [
+        // Products define the executables and libraries a package produces, and make them visible to other packages.
+        .library(
+            name: "Keychain",
+            targets: ["Keychain"]),
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        // .package(url: /* package url */, from: "1.0.0"),
+        .package(url: "https://github.com/apple/swift-crypto.git",
+                         from: "2.0.0"),
+        .package(url: "https://github.com/OperatorFoundation/KeychainLinux.git", from: "1.0.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages this package depends on.
+        .target(
+            name: "Keychain",
+            dependencies: [
+                "KeychainLinux",
+                .product(name: "Crypto", package: "swift-crypto"),
+            ]),
+        .testTarget(
+            name: "KeychainTests",
+            dependencies: ["Keychain", "KeychainLinux"]),
+    ],
+    swiftLanguageVersions: [.v5]
+)
+#endif

Sources/Keychain/Keychain.swift

@@ -2,7 +2,7 @@
 import Crypto
 import Foundation
 
-
+#if os(macOS)
 public class Keychain
 {
     public init() {}
@@ -155,3 +155,8 @@ public class Keychain
         }
     }
 }
+#else
+
+@_exported import KeychainLinux
+
+#endif