NetBSD/sys/crypto/cast128/cast128_cbc.c

223 lines
5.1 KiB
C

/* $NetBSD: cast128_cbc.c,v 1.1.1.1 2000/06/14 19:45:34 thorpej Exp $ */
/* $KAME: cast128_cbc.c,v 1.4 2000/06/14 10:41:17 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* based on sys/crypto/des/des_cbc.c, rewrote by Tomomi Suzuki
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <crypto/cast128/cast128.h>
#define panic(x) do { printf(x); return EINVAL; } while (0)
int
cast128_cbc_process(m0, skip, length, subkey, iv, keylen, mode)
struct mbuf *m0;
size_t skip;
size_t length;
u_int32_t *subkey;
u_int8_t *iv;
size_t keylen;
int mode;
{
struct mbuf *m;
u_int8_t inbuf[8], outbuf[8];
size_t off;
/* sanity check */
if (m0->m_pkthdr.len < skip) {
printf("cast128_cbc_process: mbuf length < skip\n");
return EINVAL;
}
if (m0->m_pkthdr.len < length) {
printf("cast128_cbc_process: mbuf length < encrypt length\n");
return EINVAL;
}
if (m0->m_pkthdr.len < skip + length) {
printf("cast128_cbc_process: "
"mbuf length < skip + encrypt length\n");
return EINVAL;
}
if (length % 8) {
printf("cast128_cbc_process: length is not multiple of 8\n");
return EINVAL;
}
m = m0;
off = 0;
/* skip over the header */
while (skip) {
if (!m)
panic("cast128_cbc_process: mbuf chain?\n");
if (m->m_len <= skip) {
skip -= m->m_len;
m = m->m_next;
off = 0;
} else {
off = skip;
skip = 0;
}
}
/* copy iv into outbuf for XOR (encrypt) */
bcopy(iv, outbuf, 8);
/*
* encrypt/decrypt packet
*/
while (length > 0) {
int i;
if (!m)
panic("cast128_cbc_process: mbuf chain?\n");
/*
* copy the source into input buffer.
* don't update off or m, since we need to use them
* later.
*/
if (off + 8 <= m->m_len)
bcopy(mtod(m, u_int8_t *)+off, inbuf, 8);
else {
struct mbuf *n;
size_t noff;
u_int8_t *p, *in;
n = m;
noff = off;
p = mtod(n, u_int8_t *) + noff;
in = inbuf;
while (in - inbuf < 8) {
if (!p) {
panic("cast128_cbc_process: "
"mbuf chain?\n");
}
*in++ = *p++;
noff++;
if (noff < n->m_len)
continue;
do {
n = n->m_next;
} while (n && !n->m_len);
noff = 0;
if (n)
p = mtod(n, u_int8_t *);
else
p = NULL;
}
}
/* encrypt/decrypt */
switch (mode) {
case CAST128_ENCRYPT:
/* XOR */
for (i = 0; i < 8; i++)
inbuf[i] ^= outbuf[i];
/* encrypt */
if (keylen <= 80/8)
cast128_encrypt_round12(outbuf, inbuf, subkey);
else
cast128_encrypt_round16(outbuf, inbuf, subkey);
break;
case CAST128_DECRYPT:
/* decrypt */
if (keylen <= 80/8)
cast128_decrypt_round12(outbuf, inbuf, subkey);
else
cast128_decrypt_round16(outbuf, inbuf, subkey);
/* XOR */
for (i = 0; i < 8; i++)
outbuf[i] ^= iv[i];
/* copy inbuf into iv for next XOR */
bcopy(inbuf, iv, 8);
break;
}
/*
* copy the output buffer into the result.
* need to update off and m.
*/
if (off + 8 < m->m_len) {
bcopy(outbuf, mtod(m, u_int8_t *) + off, 8);
off += 8;
} else if (off + 8 == m->m_len) {
bcopy(outbuf, mtod(m, u_int8_t *) + off, 8);
do {
m = m->m_next;
} while (m && !m->m_len);
off = 0;
} else {
struct mbuf *n;
size_t noff;
u_int8_t *p, *out;
n = m;
noff = off;
p = mtod(n, u_int8_t *) + noff;
out = outbuf;
while (out - outbuf < 8) {
if (!p) {
panic("cast128_cbc_process: "
"mbuf chain?\n");
}
*p++ = *out++;
noff++;
if (noff < n->m_len)
continue;
do {
n = n->m_next;
} while (n && !n->m_len);
noff = 0;
if (n)
p = mtod(n, u_int8_t *);
else
p = NULL;
}
m = n;
off = noff;
}
length -= 8;
}
return 0;
}