static void
cts_dec (unsigned char *out, unsigned char *in, unsigned char *iv,
unsigned int len)
{
int r;
unsigned int len2;
unsigned char pn1[B], pn[B], cn[B], cn1[B];
if (len < B + 1) abort ();
len2 = (len - B - 1) & ~(B-1);
cbc_dec (out, in, iv, len2);
out += len2;
in += len2;
len -= len2;
if (len2)
iv = in - B;
if (len <= B || len > 2 * B)
abort ();
memcpy (cn1, in, B);
r = camellia_dec_blk (cn1, pn, &dctx);
if (!r) fprintf(stderr, "error, line %d\n", __LINE__), exit(1);
memset (cn, 0, sizeof(cn));
memcpy (cn, in+B, len-B);
xor (pn, pn, cn);
memcpy (cn+len-B, pn+len-B, 2*B-len);
r = camellia_dec_blk (cn, pn1, &dctx);
if (!r) fprintf(stderr, "error, line %d\n", __LINE__), exit(1);
xor (pn1, pn1, iv);
memcpy(out, pn1, B);
memcpy(out+B, pn, len-B);
}
static void cbc_test ()
{
int testno;
unsigned char tmp[4*B];
printf ("CBC tests:\n");
printf ("initial vector:");
hexdump (ivec, sizeof(ivec));
for (testno = 0; testno < NTESTS; testno++) {
unsigned len = (test_case_len[testno] + 15) & ~15;
printf ("\ntest %d - %d bytes\n", testno, len);
printf ("input:");
hexdump (test_case[testno].input, len);
printf ("\n");
cbc_enc (test_case[testno].output, test_case[testno].input, ivec, len);
printf ("output:");
hexdump (test_case[testno].output, len);
printf ("\n");
cbc_dec (tmp, test_case[testno].output, ivec, len);
if (memcmp (tmp, test_case[testno].input, len)) {
printf("cbc decrypt failed!!");
hexdump (tmp, len);
printf ("\n");
exit(1);
}
}
printf ("\n");
}
int DES::decrypt (const char key[8], char* data, int blocks, int mode)
{
if ((!data)||(blocks<1))
return 0;
deskey((unsigned char*)key, DECRYPT);
if(mode == 1)
{
cbc_dec((unsigned char*)data, (unsigned char*)data, blocks);
}
else
{
des((unsigned char*)data, (unsigned char*)data, blocks);
}
return 1;
}
