Compute SHA-1 of byte array
JavaSha1Java Problem Overview
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?
Java Solutions
Solution 1 - Java
What about:
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Formatter;
public static String SHAsum(byte[] convertme) throws NoSuchAlgorithmException{
MessageDigest md = MessageDigest.getInstance("SHA-1");
return byteArray2Hex(md.digest(convertme));
}
private static String byteArray2Hex(final byte[] hash) {
Formatter formatter = new Formatter();
for (byte b : hash) {
formatter.format("%02x", b);
}
return formatter.toString();
}
Solution 2 - Java
You can do it yourself but I would recommend to use a library that has been proven to work, like Commons Codec. The class DigestUtils has several methods to calculate hashes.
Solution 3 - Java
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);
}
}
Solution 4 - Java
From CommonCodec DigestUtils Implementation the Hex coversion after the Digest calculation as shown before :
MessageDigest md = MessageDigest.getInstance("SHA-1");
return byteArray2Hex(md.digest(convertme));
should be http://commons.apache.org/codec/apidocs/src-html/org/apache/commons/codec/binary/Hex.html#line.129 :
private static final char[] DIGITS_LOWER =
{'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
private static final char[] DIGITS_UPPER =
{'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
protected static char[] encodeHex(byte[] data, char[] toDigits) {
int l = data.length;
char[] out = new char[l << 1];
// two characters form the hex value.
for (int i = 0, j = 0; i < l; i++) {
out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
out[j++] = toDigits[0x0F & data[i]];
}
return out;
}
protected static int toDigit(char ch, int index) throws DecoderException {
int digit = Character.digit(ch, 16);
if (digit == -1) {
throw new DecoderException(
"Illegal hexadecimal character "
+ ch + " at index " + index);
}
return digit;
}
public static String exampleSha1(String convertme){
MessageDigest md = MessageDigest.getInstance("SHA-1");
byte[] encodeHex = md.digest(convertme));
return new String(encodeHex);
}
Solution 5 - Java
...another option is to use Spring:
<bean id="passwordEncoder" class="org.springframework.security.authentication.encoding.ShaPasswordEncoder">
<constructor-arg value="256"/>
</bean>
read more here
HTH
Solution 6 - Java
I Just used this to compute the hash sum inside of a dex file and compare it with the value which is saved in the dex file.
i know this code hasnt very good style but its more PoC and only needed for some research which isnt time critical. may someone can use it!
class CheckDex{
public boolean checkSHA1(File f) throws IOException, NoSuchAlgorithmException{
RandomAccessFile raf = new RandomAccessFile(f, "r");
byte[] sig = new byte[20];
raf.seek(0xC);
for(int i = 0; i < 20; i++){
sig[i] = (byte) raf.readUnsignedByte();
}
MessageDigest md = MessageDigest.getInstance("SHA-1");
byte[] code = new byte[(int) (raf.length()-32)];
for(int i = 0; i < code.length; i++){
code[i] = (byte) raf.readUnsignedByte();
}
byte[] comsig = md.digest(code);
raf.close();
return Arrays.equals(sig,comsig);
}
}
Solution 7 - Java
How about Using This:
public class sha1Calculate {
public static void main(String[] args)throws Exception
{
File file = new File("D:\\Android Links.txt");
String outputTxt= "";
String hashcode = null;
try {
FileInputStream input = new FileInputStream(file);
ByteArrayOutputStream output = new ByteArrayOutputStream ();
byte [] buffer = new byte [65536];
int l;
while ((l = input.read (buffer)) > 0)
output.write (buffer, 0, l);
input.close ();
output.close ();
byte [] data = output.toByteArray ();
MessageDigest digest = MessageDigest.getInstance( "SHA-1" );
byte[] bytes = data;
digest.update(bytes, 0, bytes.length);
bytes = digest.digest();
StringBuilder sb = new StringBuilder();
for( byte b : bytes )
{
sb.append( String.format("%02X", b) );
}
System.out.println("Digest(in hex format):: " + sb.toString());
}catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Solution 8 - Java
The following code converts the given byte[] into a String of the SHA-1 hash.
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public static String hash(byte data[]) throws NoSuchAlgorithmException
{
MessageDigest digest;
BigInteger big;
String result;
byte hash[];
digest = MessageDigest.getInstance("SHA-1");
hash = digest.digest(data);
big = new BigInteger(1, hash);
result = big.toString(16);
return result;
}
Note: The leading zeros will be trimmed. So, this may or may not work depending on your use case.