README.md: update example applet build instructions

The build system in hello-stk.git has changed. We now use ANT to build
the applets along with a more modern JAVA SDK.

Related: OS#6069

README.md

@@ -35,10 +35,10 @@ Use the hello-stk example to get started.
 
 	$ mkdir javacard
 	$ cd javacard
-	$ git clone https://git.osmocom.org/sim/sim-tools
 	$ git clone https://git.osmocom.org/sim/hello-stk
 	$ cd hello-stk
-	$ make
+	$ git submodule update --init --recursive
+	$ ant
 
 To install the applet onto a SIM card, first set the type of reader you are using.
 

shadysim/shadysim.py

@@ -114,10 +114,10 @@ class AppLoaderCommands(object):
 		# Padding if Ciphering is used
 		if ((spi_1 & 0x04) != 0): # check ciphering bit
 			len_cipher = 6 + len_sig + (len(data) / 2)
-			# 8 Byte blocksize for DES-CBC (TODO: different padding)
-			if len_cipher % 8 > 0:
-				pad_cnt = 8 - (len_cipher % 8)
-				data += '00' * pad_cnt
+			pad_cnt = 8 - (len_cipher % 8) # 8 Byte blocksize for DES-CBC (TODO: different padding)
+			# TODO: there is probably a better way to add "pad_cnt" padding bytes
+			for i in range(0, pad_cnt):
+				data = data + '00';
 
 		# CHL + SPI first octet
 		part_head = ('%02x' % (0x0D + len_sig)) + ('%02x' % (spi_1))