Merge pull request #31 from hartbit/crypto-sha256

HashAlgorithm conformance that wraps CryptoKit.SHA256

Author: neonichu

Sources/TSCBasic/HashAlgorithms.swift

@@ -8,6 +8,10 @@
  See http://swift.org/CONTRIBUTORS.txt for Swift project authors
 */
 
+#if canImport(CryptoKit)
+import CryptoKit
+#endif
+
 public protocol HashAlgorithm {
 
     /// Hashes the input bytes, returning the digest.
@@ -169,6 +173,24 @@ public struct SHA256: HashAlgorithm {
     }
 }
 
+/// Wraps CryptoKit.SHA256 to provide a HashAlgorithm conformance to it.
+@available(macOS 10.15, *)
+public struct CryptoKitSHA256: HashAlgorithm {
+    public init() {
+    }
+
+    public func hash(_ bytes: ByteString) -> ByteString {
+      #if canImport(CryptoKit)
+        return bytes.withData { data in
+            let digest = CryptoKit.SHA256.hash(data: data)
+            return ByteString(digest)
+        }
+      #else
+        fatalError("not supported on this platform")
+      #endif
+    }
+}
+
 // MARK:- Helpers
 
 private extension UInt64 {

Tests/TSCBasicTests/SHA256Tests.swift

@@ -43,4 +43,15 @@ class SHA256Tests: XCTestCase {
         let digest = SHA256().hash(ByteString(data)).hexadecimalRepresentation
         XCTAssertEqual(digest, "907422e2f24d749d0add2b504ccae8ad1aa392477591905880fb2dc494e33d63")
     }
+
+  #if os(macOS)
+    @available(macOS 10.15, *)
+    func testCryptoKitSHA256() {
+        let sha = CryptoKitSHA256()
+        XCTAssertEqual(
+            sha.hash(ByteString("The quick brown fox jumps over the lazy dog")).hexadecimalRepresentation,
+            "d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592"
+        )
+    }
+  #endif
 }