Martin Martin - 10 months ago 78
Android Question

How to SHA1 hash a string in Android?

In Objective C I've been using the following code to hash a string:

-(NSString *) sha1:(NSString*)stringToHash {
const char *cStr = [stringToHash UTF8String];
unsigned char result[20];
CC_SHA1( cStr, strlen(cStr), result );
return [NSString stringWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
result[0], result[1], result[2], result[3],
result[4], result[5], result[6], result[7],
result[8], result[9], result[10], result[11],
result[12], result[13], result[14], result[15],
result[16], result[17], result[18], result[19]

Now I need the same for Android but can't find out how to do it. I've been looking for example at this: Make SHA1 encryption on Android ?
but that doesn't give me the same result as on iPhone. Can anyone point me in the right direction?

Answer Source

You don't need andorid for this. You can just do it in simple java.

Have you tried a simple java example and see if this returns the right sha1.


public class AeSimpleSHA1 {
    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();

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

Also share what your expected sha1 should be. Maybe ObjectC is doing it wrong.