Encrypt a String with AES256/ECB/PKCS5 with a password

String+AES256ECBPKCS5.swift

// MARK: - String

extension String {
    func aes256ECBPKCS5(hexKey: String) throws -> Data {

        let keyData: NSData = try Data(hex: hexKey) as NSData
        let data: NSData = Data(utf8) as NSData

        guard let cryptData: NSMutableData = NSMutableData(length: Int(data.length) + kCCBlockSizeAES128) else {
            throw NSError(domain: "", code: 1234, userInfo: [NSLocalizedDescriptionKey: "Prepare crypt data failed"])
        }
        
        let keyLength: size_t = size_t(kCCKeySizeAES256)
        let operation: CCOperation = UInt32(kCCEncrypt)
        let algorithm: CCAlgorithm = UInt32(kCCAlgorithmAES)
        let options: CCOptions = UInt32(kCCOptionECBMode + kCCOptionPKCS7Padding) // kCCOptionPKCS7Padding used as PKCS5Padding
        var numBytesEncrypted: size_t = 0
        let cryptStatus: CCCryptorStatus = CCCrypt(
            operation,
            algorithm,
            options,
            keyData.bytes,
            keyLength,
            nil,
            data.bytes,
            data.length,
            cryptData.mutableBytes,
            cryptData.length,
            &numBytesEncrypted
        )

        if UInt32(cryptStatus) == UInt32(kCCSuccess) {
            cryptData.length = Int(numBytesEncrypted)
            var bytes: [UInt8] = Array(repeating: 0, count: cryptData.length)
            cryptData.getBytes(&bytes, length: cryptData.length)
            return Data(bytes)
        }

        throw NSError(domain: "", code: 1234, userInfo: [NSLocalizedDescriptionKey: "Key is not HEX String format"])
    }
}

// MARK: - Data

private extension Data {
    init(hex: String) throws {
        guard hex.count.isMultiple(of: 2) else {
            throw NSError(domain: "", code: 1234, userInfo: [NSLocalizedDescriptionKey: "Key is not HEX String format"])
        }

        let chars: [Character] = hex.map { $0 }
        let charCounts: StrideTo<Int> = stride(from: 0, to: chars.count, by: 2)
        let hexStrings: [String] = charCounts.map { String(chars[$0]) + String(chars[$0 + 1]) }
        let bytes: [UInt8] = hexStrings.compactMap { UInt8($0, radix: 16) }

        guard hex.count / bytes.count == 2 else {
            throw NSError(domain: "", code: 1234, userInfo: [NSLocalizedDescriptionKey: "Key is corrupted"])
        }
        self.init(bytes)
    }
}

How to use:

do {
    let encryptedData: Data = try "Hello World".aes256ECBPKCS5(hexKey: "b109dba59329b93f3fab0736d2d27e6b6a536482ef8c7fe061d7eeca68cefee6")
    print("Encrypted data: ", \(encryptedData))
} catch {
    print("Encrypted error: ", \(error))
}