java - 如何将 hexString 转换为关于 md5、sha-1 和 sha-256 的实际字符串
问题描述
我有一个根据为 md5,sha1 sha 256 命名的值将字符串转换为 hexString 的类。
如何根据这些安全算法将 hexString 转换为 String。
MD5 Hash: 06c219e5bc8378f3a8a3f83b4b7e4649 SHA-1 Hash: e9fe51f94eadabf54dbf2fbbd57188b9abee436e SHA-256 Hash: 652c7dc687d98c9889304ed2e408c74b611e86a40caa51c4b43f1dd5913c5cd0 Actual String : mysecret
这是我的代码片段,如下所示。
public class HashGenerator {
private HashGenerator() {
}
public static String generateMD5(String message) throws HashGenerationException {
return hashString(message, "MD5");
}
public static String generateSHA1(String message) throws HashGenerationException {
return hashString(message, "SHA-1");
}
public static String generateSHA256(String message) throws HashGenerationException {
return hashString(message, "SHA-256");
}
public static String convertFromMD5(String message) throws HashGenerationException{
return hexStringtoByteArray(message, "MD5");
}
public static String convertFromSHA1(String message) throws HashGenerationException{
return hexStringtoByteArray(message, "SHA-1");
}
public static String convertFromSHA256(String message) throws HashGenerationException{
return hexStringtoByteArray(message, "SHA-256");
}
private static String hashString(String message, String algorithm)
throws HashGenerationException {
try {
MessageDigest digest = MessageDigest.getInstance(algorithm);
byte[] hashedBytes = digest.digest(message.getBytes("UTF-8"));
return convertByteArrayToHexString(hashedBytes);
} catch (NoSuchAlgorithmException | UnsupportedEncodingException ex) {
throw new HashGenerationException(
"Could not generate hash from String", ex);
}
}
private static String convertByteArrayToHexString(byte[] arrayBytes) {
StringBuffer stringBuffer = new StringBuffer();
for (int i = 0; i < arrayBytes.length; i++) {
stringBuffer.append(Integer.toString((arrayBytes[i] & 0xff) + 0x100, 16)
.substring(1));
}
return stringBuffer.toString();
}
public static String hexStringtoByteArray(String str, String algorithm)
{
byte[] bytes = new byte[str.length() / 2];
for (int i = 0; i < bytes.length; i++)
{
bytes[i] = (byte) Integer
.parseInt(str.substring(2 * i, 2 * i + 2), 16);
}
try {
MessageDigest digest = MessageDigest.getInstance(algorithm);
byte[] hashedBytes = digest.digest(bytes);
return new String(hashedBytes);
} catch (Exception ex) {
throw new HashGenerationException(
"Could not generate hash from String", ex);
}
}
}
解决方案
一旦您使用 hex 字符串获得了一个字节数组hexStringtoByteArray
,您就可以使用new String(bytes, "UTF-8")
where bytes 是您方法中的字节数组来创建一个字符串。通过在创建字符串时指定 UTF-8,您将获得 hex 以外的字符。
因此,新方法如下:
public String hexStringtoByteArray(String str) {
byte[] bytes = new byte[str.length() / 2];
for (int i = 0; i < bytes.length; i++) {
bytes[i] = (byte) Integer.parseInt(str.substring(2 * i, 2 * i + 2), 16);
}
return new String(bytes, "UTF-8");
}