package ay.util;


import java.security.MessageDigest;

public class SecurityEncryptUtil {
	private static java.security.SecureRandom random = new java.security.SecureRandom();
	

	public static String md5(String source, int times) {
		String result = source;
		for (int i = 0; i < times; i++) {
			result = md5(source);
		}
		return result;
	}

	public static String sha1(String source, int times) {
		String result = source;
		for (int i = 0; i < times; i++) {
			result = sha1(source);
		}
		return result;
	}

	public static String sha256(String source, int times) {
		String result = source;
		for (int i = 0; i < times; i++) {
			result = sha256(source);
		}
		return result;
	}

	public static String sha384(String source, int times) {
		String result = source;
		for (int i = 0; i < times; i++) {
			result = sha384(source);
		}
		return result;
	}

	public static String sha512(String source, int times) {
		String result = source;
		for (int i = 0; i < times; i++) {
			result = sha512(source);
		}
		return result;
	}

	public static String md5(String source) {
		return hash("MD5", source);
	}

	public static String sha1(String source) {
		return hash("SHA-1", source);
	}

	public static String sha256(String source) {
		return hash("SHA-256", source);
	}

	public static String sha384(String source) {
		return hash("SHA-384", source);
	}

	public static String sha512(String source) {
		return hash("SHA-512", source);
	}

	public static String hash(String algorithm, String source) {
		try {
			StringBuilder result = new StringBuilder();
			MessageDigest md = MessageDigest.getInstance(algorithm);
			byte[] bytes = md.digest(source.getBytes("utf-8"));
			for (byte b : bytes) {
				String hex = Integer.toHexString(b & 0xFF);
				if (hex.length() == 1)
					result.append("0");
				result.append(hex);
			}
			return result.toString();
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	private static String toHex(byte[] bytes) {
		StringBuilder result = new StringBuilder();
		for (byte b : bytes) {
			String hex = Integer.toHexString(b & 0xFF);
			if (hex.length() == 1)
				result.append("0");
			result.append(hex);
		}
		return result.toString();
	}

	/**
	 * md5 128bit 16bytes
	 * <br/>
	 * sha1 160bit 20bytes
	 * <br/>
	 * sha256 256bit 32bytes
	 * <br/>
	 * sha384 384bit 48bites
	 * <br/>
	 * sha512 512bit 64bites
	 */
	public static String generateSalt(int numberOfBytes) {
		byte[] salt = new byte[numberOfBytes];
		random.nextBytes(salt);
		return toHex(salt);
	}
}