User Code: Make an SHA Fingerprint from a String

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Originally published at Internet.com

It's possible, in an applet, that this code won't work for some Netscape Navigator versions, because they don't have the MessageDigest class included (perhaps this only concerns European versions, because of some export restrictions to cryptographic code).

In that case, as far as I know, the only way to implement the SHA is to follow Steve Reid's originial C++ code step by step. But there also exist some Java translations on the Net.

How It Works

You just call makeSHA("Hello World!"), and you'll get back a string consisting of the hex-view of the encoded bytes.

import java.io.*; import java.lang.*; import java.security.*; import java.util.*; public class mysha { public static String toHexString(byte b) { int value = (b & 0x7F) + (b < 0 ? 128 : 0); String ret = (value < 16 ? "0" : ""); ret += Integer.toHexString(value).toUpperCase(); return ret; } public static String makeSHA(String inputstring) { String outputstring=""; try { // Objekt mit SHA" holen => initialize SHA object MessageDigest md = MessageDigest.getInstance("SHA"); byte[] myText = inputstring.getBytes(); md.update(myText); // Berechnen => Calculate byte[] result = md.digest(); // Ausgeben => Output for (int i = 0; i < result.length; ++i) { outputstring=outputstring+toHexString(result[i]); } } catch ( Exception e) { System.out.println("Error"+e); } return outputstring; } public static void main(String arguments[]) { // runs test-vector "abc" System.out.println(makeSHA("abc")); } }

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