摘要算法:SHA 及 Java 實現樣例
相關鏈接:摘要算法:MD5及Java實現樣例
SHA = 安全散列算法(Secure Hash Algorithm)。
SHA 與 MD5 類似,都是單向不可逆散列函數,用於計算消息摘要,生成消息數字簽名(指紋)。
Algorithm | 散列值長度(單位比特) |
---|---|
SHA-1 | 160 |
SHA-224 | 224 |
SHA-256 | 256 |
SHA-384 | 384 |
SHA-512 | 512 |
Java 實現樣例:
import java.security.MessageDigest;
public class MySHA {
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
String msg = "0123456789abcdef";
{
MessageDigest sha = MessageDigest.getInstance("SHA");
sha.update(msg.getBytes());
byte []shaBin = sha.digest();
printBytes(shaBin);
}
{
MessageDigest sha1 = MessageDigest.getInstance("SHA-1");
sha1.update(msg.getBytes());
byte []sha1Bin = sha1.digest();
printBytes(sha1Bin);
}
{
MessageDigest sha224 = MessageDigest.getInstance("SHA-224");
sha224.update(msg.getBytes());
byte []sha224Bin = sha224.digest();
printBytes(sha224Bin);
}
{
MessageDigest sha256 = MessageDigest.getInstance("SHA-256");
sha256.update(msg.getBytes());
byte []sha256Bin = sha256.digest();
printBytes(sha256Bin);
}
{
MessageDigest sha384 = MessageDigest.getInstance("SHA-384");
sha384.update(msg.getBytes());
byte []sha384Bin = sha384.digest();
printBytes(sha384Bin);
}
{
MessageDigest sha512 = MessageDigest.getInstance("SHA-512");
sha512.update(msg.getBytes());
byte []sha512Bin = sha512.digest();
printBytes(sha512Bin);
}
}
/**
* 十六進制打印字節數組
* @param b byte[]
*/
public static void printBytes(byte[] b)
{
for(int i=0;i<b.length;i++)
{
System.out.printf("%02X", b[i]);
}
System.out.println();
}
}
注:散列值都是按照十六進制大寫字母編碼表示。