How to SHA1 hash a string in Android?

Question

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 1

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.

import java.io.UnsupportedEncodingException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException;  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.

Answer 2

A simpler SHA-1 method: (updated from the commenter's suggestions, also using a massively more efficient byte->string algorithm)

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 ); }