Java Compute SHA-1

Question

I'm looking for a way of getting an SHA-1 checksum with a Java byte array as the message

Should I use a third party tool or is there something built in to the JVM that can help?

Answer 1

What about:

import java.security.MessageDigest;

public static String SHAsum(byte[] convertme) {
    MessageDigest md = MessageDigest.getInstance("SHA-1"); 
    return String sum = new String(md.digest(convertme));
}

Answer 2

This a snippet of code we use to convert to SHA-1 but takes a String instead of a Byte[] see this javadoc for further info

        import java.io.UnsupportedEncodingException;
        import java.security.MessageDigest;
        import java.security.NoSuchAlgorithmException;

        public class DoSHA1 {

            private static String convToHex(byte[] data) {
                StringBuilder buf = new StringBuilder();
                for (int i = 0; i < data.length; i++) {
                    int halfbyte = (data[i] >>> 4) & 0x0F;
                    int two_halfs = 0;
                    do {
                        if ((0 <= halfbyte) && (halfbyte <= 9))
                            buf.append((char) ('0' + halfbyte));
                        else
                         buf.append((char) ('a' + (halfbyte - 10)));
                        halfbyte = data[i] & 0x0F;
                    } while(two_halfs++ < 1);
                }
                return buf.toString();
            }

            public static String SHA1(String text) throws NoSuchAlgorithmException,
UnsupportedEncodingException  {
            MessageDigest md = MessageDigest.getInstance("SHA-1");
            byte[] sha1hash = new byte[40];
            md.update(text.getBytes("iso-8859-1"), 0, text.length());
            sha1hash = md.digest();
            return convToHex(sha1hash);
            }
        }