Use #if canImport(Darwin) where possible (#148)

Co-authored-by: Cory Benfield <[email protected]>

Author: FranzBusch

Sources/NIOSSH/CSPRNG/CSPRNG.swift

@@ -31,7 +31,7 @@ struct CSPRNG: RandomNumberGenerator {
     private var baseRNG: SystemRandomNumberGenerator
 
     init() {
-        #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS) || os(Linux) || os(Android)
+        #if canImport(Darwin) || os(Linux) || os(Android)
         self.baseRNG = SystemRandomNumberGenerator()
         #else
         fatalError("Platform does not have a supported CSPRNG")

Sources/NIOSSH/Keys And Signatures/NIOSSHCertifiedPublicKey.swift

@@ -15,11 +15,11 @@
 import Crypto
 import Dispatch
 import NIOCore
-#if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+#if canImport(Darwin)
 import Darwin
 #else
 import Glibc
-#endif // os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+#endif // canImport(Darwin)
 
 /// A ``NIOSSHCertifiedPublicKey`` is an SSH public key combined with an SSH certificate.
 ///

Sources/NIOSSH/Keys And Signatures/NIOSSHPrivateKey.swift

@@ -46,7 +46,7 @@ public struct NIOSSHPrivateKey {
         self.backingKey = .ecdsaP521(key)
     }
 
-    #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+    #if canImport(Darwin)
     public init(secureEnclaveP256Key key: SecureEnclave.P256.Signing.PrivateKey) {
         self.backingKey = .secureEnclaveP256(key)
     }
@@ -63,7 +63,7 @@ public struct NIOSSHPrivateKey {
             return ["ecdsa-sha2-nistp384"]
         case .ecdsaP521:
             return ["ecdsa-sha2-nistp521"]
-        #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+        #if canImport(Darwin)
         case .secureEnclaveP256:
             return ["ecdsa-sha2-nistp256"]
         #endif
@@ -79,7 +79,7 @@ extension NIOSSHPrivateKey {
         case ecdsaP384(P384.Signing.PrivateKey)
         case ecdsaP521(P521.Signing.PrivateKey)
 
-        #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+        #if canImport(Darwin)
         case secureEnclaveP256(SecureEnclave.P256.Signing.PrivateKey)
         #endif
     }
@@ -109,7 +109,7 @@ extension NIOSSHPrivateKey {
             }
             return NIOSSHSignature(backingSignature: .ecdsaP521(signature))
 
-        #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+        #if canImport(Darwin)
         case .secureEnclaveP256(let key):
             let signature = try digest.withUnsafeBytes { ptr in
                 try key.signature(for: ptr)
@@ -133,7 +133,7 @@ extension NIOSSHPrivateKey {
         case .ecdsaP521(let key):
             let signature = try key.signature(for: payload.bytes.readableBytesView)
             return NIOSSHSignature(backingSignature: .ecdsaP521(signature))
-        #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+        #if canImport(Darwin)
         case .secureEnclaveP256(let key):
             let signature = try key.signature(for: payload.bytes.readableBytesView)
             return NIOSSHSignature(backingSignature: .ecdsaP256(signature))
@@ -154,7 +154,7 @@ extension NIOSSHPrivateKey {
             return NIOSSHPublicKey(backingKey: .ecdsaP384(privateKey.publicKey))
         case .ecdsaP521(let privateKey):
             return NIOSSHPublicKey(backingKey: .ecdsaP521(privateKey.publicKey))
-        #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+        #if canImport(Darwin)
         case .secureEnclaveP256(let privateKey):
             return NIOSSHPublicKey(backingKey: .ecdsaP256(privateKey.publicKey))
         #endif

Tests/NIOSSHTests/EndToEndTests.swift

@@ -411,7 +411,7 @@ class EndToEndTests: XCTestCase {
     func testSecureEnclaveKeys() throws {
         // This is a quick end-to-end test that validates that we support secure enclave private keys
         // on appropriate platforms.
-        #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+        #if canImport(Darwin)
         // If we can't create this key, we skip the test.
         let key: NIOSSHPrivateKey
         do {