[GNU Crypto] GNU crypto and gcj

[Casey Marshall]

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Hello,

I think I've found the reason why all the cipher tests fail when
compiled natively with gcj -O2: the toBytesFromString method in
gnu.crypto.util.Util.

This program:

- ------

import gnu.crypto.util.Util;

class utilTest {
   public static void main(String[] argv) throws Throwable {
      byte[] b = new byte[] {
         0x01, 0x23, 0x45, 0x67, (byte) 0x89, (byte) 0xab,
         (byte) 0xcd, (byte) 0xef
      };
      String s = "0123456789abcdef";
      System.err.println(Util.toString(b));
      System.err.println(s);
      System.err.println(Util.toString(Util.toBytesFromString(s)));
   }
}

- ------

when compiled, linked, and run with the gnu-crypto libraries prints out

0123456789abcdef
0123456789abcdef
1032547698badcfe

So it appears that when gcj -O2 compiles the statement

result[j++] = (byte)((fromDigit(s.charAt(i++)) << 4) |
fromDigit(s.charAt(i++)));

it flips the order of the two calls to 'fromDigit(s.charAt(i++))',
swapping the lower four bits and the top four for each byte.

The attached patch will fix the gcj build. If someone can confirm this
fix I'll check it in.

This result is with GCC 3.1; I don't know if the problem exists with
more recent versions.

Cheers,

- --
Casey Marshall < address@hidden > http://metastatic.org/
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util-patch
Description: application/java-vm