Add test vectors

Author: bauer-andreas

Tests/CryptoExtrasTests/SHA512256Tests.swift

@@ -0,0 +1,97 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftCrypto open source project
+//
+// Copyright (c) 2026 Apple Inc. and the SwiftCrypto project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftCrypto project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import Crypto
+import CryptoExtras
+import XCTest
+
+final class SHA512256DigestTests: XCTestCase {
+    func testHashFunction() throws {
+        let data =
+            "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu"
+            .data(using: .ascii)!
+
+        var hasher = SHA512256()
+        hasher.update(data: data)
+        let digest = hasher.finalize()
+
+        let expected = try Array(hexString: "3928e184fb8690f840da3988121d31be65cb9d3ef83ee6146feac861e19b563a")
+        XCTAssertEqual(Array(digest), expected)
+        XCTAssertEqual(Array(SHA512256.hash(data: data)), expected)
+
+        let (contiguousResult, discontiguousResult) = expected.asDataProtocols()
+        XCTAssert(digest == contiguousResult)
+        XCTAssert(digest == discontiguousResult)
+        XCTAssertFalse(digest == DispatchData.empty)
+    }
+
+    func testNullHash() throws {
+        let digest = SHA512256.hash(data: Data())
+
+        let expected = try Array(hexString: "c672b8d1ef56ed28ab87c3622c5114069bdd3ad7b8f9737498d0c01ecef0967a")
+        XCTAssertEqual(Array(digest), expected)
+    }
+
+    func testABC() throws {
+        let digest = SHA512256.hash(data: "abc".data(using: .ascii)!)
+
+        let expected = try Array(hexString: "53048e2681941ef99b2e29b76b4c7dabe4c2d0c634fc6d46e0e2f13107e7af23")
+        XCTAssertEqual(Array(digest), expected)
+    }
+
+    func testTwoBlockMessage() throws {
+        let data = "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopmopq".data(using: .ascii)!
+        let digest = SHA512256.hash(data: data)
+
+        let expected = try Array(hexString: "35de8c8794b9ed4b463c257fe50e62b516e07976a2931f4f78f1cd69a456dccd")
+        XCTAssertEqual(Array(digest), expected)
+    }
+
+    func testSingleByte() throws {
+        let digest = SHA512256.hash(data: Data([0x61]))
+
+        let expected = try Array(hexString: "455e518824bc0601f9fb858ff5c37d417d67c2f8e0df2babe4808858aea830f8")
+        XCTAssertEqual(Array(digest), expected)
+    }
+
+    func testRepeatedBytes() throws {
+        let data = Data(repeating: 0x61, count: 1_000_000)
+        let digest = SHA512256.hash(data: data)
+
+        let expected = try Array(hexString: "9a59a052930187a97038cae692f30708aa6491923ef5194394dc68d56c74fb21")
+        XCTAssertEqual(Array(digest), expected)
+    }
+
+    func testCopyOnWrite() {
+        var hasher = SHA512256()
+        hasher.update(data: [1, 2, 3, 4])
+
+        var copy = hasher
+        hasher.update(data: [5, 6, 7, 8])
+        let digest = hasher.finalize()
+
+        copy.update(data: [5, 6, 7, 8])
+        let copyDigest = copy.finalize()
+
+        XCTAssertEqual(digest, copyDigest)
+    }
+
+    func testBlockSize() {
+        XCTAssertEqual(SHA512256.blockByteCount, 128)
+    }
+
+    func testDigestByteCount() {
+        XCTAssertEqual(SHA512256Digest.byteCount, 32)
+    }
+}