Re: Testing XTEA



Mike Simpson wrote:
"Mike Amling" <spamonly@xxxxxxxxxxx> wrote in message news:ene34i$6v6@xxxxxxxxxxxxxxxxxxxxxxxxxx
Mike Simpson wrote:
Thanks Mike, Woolfgang and Tom. The program works well with your plaintexts and cyphertexts, but I still don't get anything meaningfule with the Keith Lockstone vectors - so the problem must be my understanding of those vectors.
Forgive my ignorance, but what are the Keith Lockstone vectors? I may have missed a post somewhere.

--Mike Amling

Mentioned in several of the sites I came across when trying to find some way of checking that my
program was giving the right result. URL is

http://www.cix.co.uk/~klockstone/teavect.htm

Note that the code on that web page does not compile. In the tean() function, the first "else" needs a closing brace in front of it. But once that's done it does produce the XTEA output claimed.
I confirmed those XTEA results using the following small Java program.

int[] pz=new int[6], key=new int[4];
for (int jj=1; jj<=64; ++jj) {
System.arraycopy(pz, 2, key, 0, 4);
XTEA.encipher(pz, key, jj);
if ((jj & -jj)==jj) {
System.out.println(jj);
hexdump(pz);
}
int save=pz[0];
System.arraycopy(pz, 1, pz, 0, 5);
pz[5]=save;
}

Notes: It's a little odd to vary the XTEA iteration count rather than just use 32. hexdump() is a utility I wrote. The last three lines in the loop do a Rotate-Left of pz's six elements.
1
000000 .....7y......... 00000000 9E3779B9 00000000 00000000
000010 ........ 00000000 00000000
2
000000 ......%m........ EC01A1DE AAA0256D 00000000 00000000
000010 ........ 00000000 00000000
4
000000 .:}.N#.......... BC3A7DE2 4E238EB9 00000000 00000000
000010 .....Omt EC01A1DE 114F6D74
8
000000 1..l$.V..:}..XF. 31C5FA6C 241756D6 BC3A7DE2 845846CF
000010 '..'k... 2794A127 6B8EA8B8
16
000000 ..i..G..j.x...mg 1D8E6992 9A478905 6A1D78C8 08C86D67
000010 *e....nF 2A65BFBE B4BD6E46
32
000000 .d(.. ".'....... D26428AF 0A202283 27F917B1 C1DA8993
000010 `......= 60E2ACAA A6EB923D
64
000000 z....=`hb. ...z. 7A01CBC9 B03D6068 62EE209F 069B7AFC
000010 7j.6...# 376A8936 CDC9E923

HTH

--Mike Amling
.