架构师训练营第十一周作业

public interface IHasher {
	String hash(String source);
}

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.util.Objects;
import org.apache.commons.codec.binary.Hex;
/**
 * 基于md5的hash
 */
public class MD5Hasher implements IHasher {
	
	@Override
	public String hash(String source) {
		source = Objects.requireNonNull(source);
		try {
			MessageDigest md5 = MessageDigest.getInstance("md5");
			return Hex.encodeHexString(md5.digest(source.getBytes(StandardCharsets.UTF_8)));
		} catch (Exception e) {
			throw new IllegalStateException(e);
		}
	}
}

public interface IPasswordChecker {
	boolean checkPW(String userId, String password, String encryptPassword);
}

/**
 * 简单的密码检查
 */
public class SimplePasswordChecker implements IPasswordChecker {
	private final IHasher hasher;
	public SimplePasswordChecker(IHasher hasher) {
		this.hasher = hasher;
	}
	
	@Override
	public boolean checkPW(String userId, String password, String encryptPassword) {
		String hash = hasher.hash("simple_" + userId + "_" + password + "_" + getUserSalt(userId));
//		System.out.println(hash);
		return hash.equals(encryptPassword);
	}
	
	/**
	 * 根据用户id返回特定的salt，这里为了简化，直接返回某个固定的值
	 * @param userId
	 * @return
	 */
	protected String getUserSalt(String userId) {
		return "TODO";
	}
}

public class Main {
	public static void main(String[] args) {
		IPasswordChecker checker = new SimplePasswordChecker(new MD5Hasher());
		System.out.println(checker.checkPW("user", "password", "a16c6d10c839e8e0e3141f654e008aa4"));
	}
}