Example Analysis of C # cryptographic class tools

5.SHA1 encryption

SHA1 Encrypt public    static string getSha1 (String str) {        if (str==null| | Str.length () ==0) {            return null;        }                Char hexdigits[] = {' 0 ', ' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ', ' 6 ', ' 7 ', ' 8 ', ' 9 ', ' A ', ' B ', ' C ', ' d ', ' e ', ' f '};                try {            MessageDigest mdtemp = messagedigest.getinstance ("SHA1");            Mdtemp.update (Str.getbytes ("UTF-8"));                        byte[] MD = Mdtemp.digest ();                        int j = md.length;                        Char buf[] = new char[j*2];                        int k = 0;                        for (int i = 0; i < J; i++) {                            byte byte0 = md[i];                buf[k++] = hexdigits[byte0 >>> 4 & 0xf];                buf[k++] = hexdigits[byte0 & 0xf];            }            return new String (BUF);        } catch (Exception e) {                    return null;        }    }

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6.MD5 encryption Tool Class:

Package Com.huihui.util;import java.security.messagedigest;/** * MD5 Encryption Tool class * @author Administrator * */public class Md5uti L {public final static string MD5 (string s) {char hexdigits[] = {' 0 ', ' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ', ' 6 ', ' 7 ', ' 8 ', ' 9 ', ' a ',         ' B ', ' C ', ' d ', ' e ', ' f '};            try {byte[] strtemp = S.getbytes ();            MessageDigest mdtemp = messagedigest.getinstance ("MD5");                        Mdtemp.update (strtemp);                        byte[] MD = Mdtemp.digest ();                        int j = Md.length;                        Char str[] = new CHAR[J*2];                        int k = 0;                for (int i = 0; i < J; i++) {byte byte0 = md[i];                str[k++] = hexdigits[byte0>>>4&0xf];            str[k++] = hexdigits[byte0 & 0xf];        } return new String (str);        } catch (Exception e) {return null;       }} public static void Main (string[] args) { System.out.println (MD5UTIL.MD5 ("B")); }}