I am currently developing a distributed system application. I want to verify a Python generated hash in the Android application. I have a python method to do hashing in given string variables.
This is the python function and it works well.
hash_value = hashlib.sha1("PARAMETER123".encode("UTF-8")).hexdigest()
I want to implement the same function in my Android application. I hope some expert can help as soon as possible.
You can try the following code snippet,
String text = "PARAMETER123";
MessageDigest md = MessageDigest.getInstance("SHA-1");
byte[] textBytes = text.getBytes("UTF-8");
md.update(textBytes, 0, textBytes.length);
byte[] sha1hash = md.digest();
String encrypted_text = = convertToHex(sha1hash);
and the convertToHex() method
private static String convertToHex(byte[] data) {
StringBuilder buf = new StringBuilder();
for (byte b : data) {
int halfbyte = (b >>> 4) & 0x0F;
int two_halfs = 0;
do {
buf.append((0 <= halfbyte) && (halfbyte <= 9) ? (char) ('0' + halfbyte) : (char) ('a' + (halfbyte - 10)));
halfbyte = b & 0x0F;
} while (two_halfs++ < 1);
}
return buf.toString();
}
This will convert a UTF-8 based text into a SHA1 hex.
Reference: https://stackoverflow.com/a/5980789/2506025
Here is a simple SHA1 method for Java:
String sha1Hash( String toHash )
{
String hash = null;
try
{
MessageDigest digest = MessageDigest.getInstance( "SHA-1" );
byte[] bytes = toHash.getBytes("UTF-8");
digest.update(bytes, 0, bytes.length);
bytes = digest.digest();
// This is ~55x faster than looping and String.formating()
hash = bytesToHex( bytes );
}
catch( NoSuchAlgorithmException e )
{
e.printStackTrace();
}
catch( UnsupportedEncodingException e )
{
e.printStackTrace();
}
return hash;
}
// http://stackoverflow.com/questions/9655181/convert-from-byte-array-to-hex-string-in-java
final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
public static String bytesToHex( byte[] bytes )
{
char[] hexChars = new char[ bytes.length * 2 ];
for( int j = 0; j < bytes.length; j++ )
{
int v = bytes[ j ] & 0xFF;
hexChars[ j * 2 ] = hexArray[ v >>> 4 ];
hexChars[ j * 2 + 1 ] = hexArray[ v & 0x0F ];
}
return new String( hexChars );
}
You can include those methods and call sha1hash.
