passepartout-apple/Packages/PassepartoutOpenVPNOpenSSL/Tests/CPassepartoutCryptoOpenSSLTests/CryptoCBCTests.swift

//
//  CryptoCBCTests.swift
//  PassepartoutKit
//
//  Created by Davide De Rosa on 12/12/23.
//  Copyright (c) 2025 Davide De Rosa. All rights reserved.
//
//  https://github.com/passepartoutvpn
//
//  This file is part of PassepartoutKit.
//
//  PassepartoutKit is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  PassepartoutKit is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with PassepartoutKit.  If not, see <http://www.gnu.org/licenses/>.
//

internal import CPassepartoutCryptoOpenSSL
@testable import PassepartoutCryptoOpenSSL
import XCTest

final class CryptoCBCTests: XCTestCase {
    func test_givenDecrypted_whenEncryptWithoutCipher_thenEncodesWithHMAC() {
        let sut = CryptoCBC(cipherName: nil, digestName: "sha256")
        sut.configureEncryption(withCipherKey: nil, hmacKey: hmacKey)

        do {
            var flags = newFlags()
            let returnedData = try sut.encryptData(plainData, flags: &flags)
            XCTAssertEqual(returnedData, plainHMACData)
        } catch {
            XCTFail("Cannot encrypt: \(error)")
        }
    }

    func test_givenDecrypted_whenEncryptWithCipher_thenEncryptsWithHMAC() {
        let sut = CryptoCBC(cipherName: "aes-128-cbc", digestName: "sha256")
        sut.configureEncryption(withCipherKey: cipherKey, hmacKey: hmacKey)

        do {
            var flags = newFlags()
            let returnedData = try sut.encryptData(plainData, flags: &flags)
            XCTAssertEqual(returnedData, encryptedHMACData)
        } catch {
            XCTFail("Cannot encrypt: \(error)")
        }
    }

    func test_givenEncodedWithHMAC_thenDecodes() {
        let sut = CryptoCBC(cipherName: nil, digestName: "sha256")
        sut.configureDecryption(withCipherKey: nil, hmacKey: hmacKey)

        do {
            var flags = newFlags()
            let returnedData = try sut.decryptData(plainHMACData, flags: &flags)
            XCTAssertEqual(returnedData, plainData)
        } catch {
            XCTFail("Cannot decrypt: \(error)")
        }
    }

    func test_givenEncryptedWithHMAC_thenDecrypts() {
        let sut = CryptoCBC(cipherName: "aes-128-cbc", digestName: "sha256")
        sut.configureDecryption(withCipherKey: cipherKey, hmacKey: hmacKey)

        do {
            var flags = newFlags()
            let returnedData = try sut.decryptData(encryptedHMACData, flags: &flags)
            XCTAssertEqual(returnedData, plainData)
        } catch {
            XCTFail("Cannot decrypt: \(error)")
        }
    }

    func test_givenHMAC_thenVerifies() {
        let sut = CryptoCBC(cipherName: nil, digestName: "sha256")
        sut.configureDecryption(withCipherKey: nil, hmacKey: hmacKey)

        var flags = newFlags()
        XCTAssertNoThrow(try sut.verifyData(plainHMACData, flags: &flags))
        XCTAssertNoThrow(try sut.verifyData(encryptedHMACData, flags: &flags))
    }
}

private extension CryptoCBCTests {
    var cipherKey: ZeroingData {
        ZeroingData(length: 32)
    }

    var hmacKey: ZeroingData {
        ZeroingData(length: 32)
    }

    var plainData: Data {
        Data(hex: "00112233ffddaa")
    }

    var plainHMACData: Data {
        Data(hex: "8dd324c81ca32f52e4aa1aa35139deba799a68460e80b0e5ac8bceb043edf6e500112233ffddaa")
    }

    var encryptedHMACData: Data {
        Data(hex: "fea3fe87ee68eb21c697e62d3c29f7bea2f5b457d9a7fa66291322fc9c2fe6f700000000000000000000000000000000ebe197e706c3c5dcad026f4e3af1048b")
    }

    var packetId: [UInt8] {
        [0x56, 0x34, 0x12, 0x00]
    }

    var ad: [UInt8] {
        [0x00, 0x12, 0x34, 0x56]
    }

    func newFlags() -> CryptoFlags {
        packetId.withUnsafeBufferPointer { iv in
            ad.withUnsafeBufferPointer { ad in
                CryptoFlags(
                    iv: iv.baseAddress,
                    ivLength: iv.count,
                    ad: ad.baseAddress,
                    adLength: ad.count,
                    forTesting: true
                )
            }
        }
    }
}