/*
* Apply a symmetric encryption/decryption algorithm.
*/
static int
swcr_encdec(struct cryptodesc *crd, struct swcr_data *sw, caddr_t buf,
int outtype)
{
unsigned char iv[EALG_MAX_BLOCK_LEN], blk[EALG_MAX_BLOCK_LEN], *idat;
unsigned char *ivp, piv[EALG_MAX_BLOCK_LEN];
struct enc_xform *exf;
int i, k, j, blks;
exf = sw->sw_exf;
blks = exf->blocksize;
/* Check for non-padded data */
if (crd->crd_len % blks)
return EINVAL;
/* Initialize the IV */
if (crd->crd_flags & CRD_F_ENCRYPT) {
/* IV explicitly provided ? */
if (crd->crd_flags & CRD_F_IV_EXPLICIT)
bcopy(crd->crd_iv, iv, blks);
else {
/* Get random IV */
for (i = 0;
i + sizeof (u_int32_t) < EALG_MAX_BLOCK_LEN;
i += sizeof (u_int32_t)) {
u_int32_t temp = arc4random();
bcopy(&temp, iv + i, sizeof(u_int32_t));
}
/*
* What if the block size is not a multiple
* of sizeof (u_int32_t), which is the size of
* what arc4random() returns ?
*/
if (EALG_MAX_BLOCK_LEN % sizeof (u_int32_t) != 0) {
u_int32_t temp = arc4random();
bcopy (&temp, iv + i,
EALG_MAX_BLOCK_LEN - i);
}
}
/* Do we need to write the IV */
if (!(crd->crd_flags & CRD_F_IV_PRESENT)) {
COPYBACK(outtype, buf, crd->crd_inject, blks, iv);
}
} else { /* Decryption */
/* IV explicitly provided ? */
if (crd->crd_flags & CRD_F_IV_EXPLICIT)
bcopy(crd->crd_iv, iv, blks);
else {
/* Get IV off buf */
COPYDATA(outtype, buf, crd->crd_inject, blks, iv);
}
}
ivp = iv;
if (outtype == CRYPTO_BUF_CONTIG) {
if (crd->crd_flags & CRD_F_ENCRYPT) {
for (i = crd->crd_skip;
i < crd->crd_skip + crd->crd_len; i += blks) {
/* XOR with the IV/previous block, as appropriate. */
if (i == crd->crd_skip)
for (k = 0; k < blks; k++)
buf[i + k] ^= ivp[k];
else
for (k = 0; k < blks; k++)
buf[i + k] ^= buf[i + k - blks];
exf->encrypt(sw->sw_kschedule, buf + i);
}
} else { /* Decrypt */
/*
* Start at the end, so we don't need to keep the encrypted
* block as the IV for the next block.
*/
for (i = crd->crd_skip + crd->crd_len - blks;
i >= crd->crd_skip; i -= blks) {
exf->decrypt(sw->sw_kschedule, buf + i);
/* XOR with the IV/previous block, as appropriate */
if (i == crd->crd_skip)
for (k = 0; k < blks; k++)
buf[i + k] ^= ivp[k];
else
for (k = 0; k < blks; k++)
buf[i + k] ^= buf[i + k - blks];
}
}
return 0;
} else if (outtype == CRYPTO_BUF_MBUF) {
struct mbuf *m = (struct mbuf *) buf;
/* Find beginning of data */
m = m_getptr(m, crd->crd_skip, &k);
if (m == NULL)
return EINVAL;
i = crd->crd_len;
while (i > 0) {
/*
* If there's insufficient data at the end of
* an mbuf, we have to do some copying.
*/
if (m->m_len < k + blks && m->m_len != k) {
m_copydata(m, k, blks, blk);
/* Actual encryption/decryption */
if (crd->crd_flags & CRD_F_ENCRYPT) {
/* XOR with previous block */
for (j = 0; j < blks; j++)
blk[j] ^= ivp[j];
exf->encrypt(sw->sw_kschedule, blk);
/*
* Keep encrypted block for XOR'ing
* with next block
*/
bcopy(blk, iv, blks);
ivp = iv;
} else { /* decrypt */
/*
* Keep encrypted block for XOR'ing
* with next block
*/
if (ivp == iv)
bcopy(blk, piv, blks);
else
bcopy(blk, iv, blks);
exf->decrypt(sw->sw_kschedule, blk);
/* XOR with previous block */
for (j = 0; j < blks; j++)
blk[j] ^= ivp[j];
if (ivp == iv)
bcopy(piv, iv, blks);
else
ivp = iv;
}
/* Copy back decrypted block */
m_copyback(m, k, blks, blk);
/* Advance pointer */
m = m_getptr(m, k + blks, &k);
if (m == NULL)
return EINVAL;
i -= blks;
/* Could be done... */
if (i == 0)
break;
}
/* Skip possibly empty mbufs */
if (k == m->m_len) {
for (m = m->m_next; m && m->m_len == 0;
m = m->m_next)
;
k = 0;
}
/* Sanity check */
if (m == NULL)
return EINVAL;
/*
* Warning: idat may point to garbage here, but
* we only use it in the while() loop, only if
* there are indeed enough data.
*/
idat = mtod(m, unsigned char *) + k;
while (m->m_len >= k + blks && i > 0) {
if (crd->crd_flags & CRD_F_ENCRYPT) {
/* XOR with previous block/IV */
for (j = 0; j < blks; j++)
idat[j] ^= ivp[j];
exf->encrypt(sw->sw_kschedule, idat);
ivp = idat;
} else { /* decrypt */
/*
* Keep encrypted block to be used
* in next block's processing.
*/
if (ivp == iv)
bcopy(idat, piv, blks);
else
bcopy(idat, iv, blks);
exf->decrypt(sw->sw_kschedule, idat);
/* XOR with previous block/IV */
for (j = 0; j < blks; j++)
idat[j] ^= ivp[j];
if (ivp == iv)
bcopy(piv, iv, blks);
else
ivp = iv;
}
idat += blks;
k += blks;
i -= blks;
}
}
return 0; /* Done with mbuf encryption/decryption */
} else if (outtype == CRYPTO_BUF_IOV) {
/*
* Apply a symmetric encryption/decryption algorithm.
*/
int
swcr_encdec(struct cryptodesc *crd, struct swcr_data *sw, caddr_t buf,
int outtype)
{
unsigned char iv[EALG_MAX_BLOCK_LEN], blk[EALG_MAX_BLOCK_LEN], *idat;
unsigned char *ivp, piv[EALG_MAX_BLOCK_LEN];
struct enc_xform *exf;
int i, k, j, blks, ind, count, ivlen;
struct mbuf *m = NULL;
struct uio *uio = NULL;
exf = sw->sw_exf;
blks = exf->blocksize;
ivlen = exf->ivsize;
/* Check for non-padded data */
if (crd->crd_len % blks)
return EINVAL;
if (outtype == CRYPTO_BUF_MBUF)
m = (struct mbuf *) buf;
else
uio = (struct uio *) buf;
/* Initialize the IV */
if (crd->crd_flags & CRD_F_ENCRYPT) {
/* IV explicitly provided ? */
if (crd->crd_flags & CRD_F_IV_EXPLICIT)
bcopy(crd->crd_iv, iv, ivlen);
else
arc4random_bytes(iv, ivlen);
/* Do we need to write the IV */
if (!(crd->crd_flags & CRD_F_IV_PRESENT)) {
COPYBACK(outtype, buf, crd->crd_inject, ivlen, iv);
}
} else { /* Decryption */
/* IV explicitly provided ? */
if (crd->crd_flags & CRD_F_IV_EXPLICIT)
bcopy(crd->crd_iv, iv, ivlen);
else {
/* Get IV off buf */
COPYDATA(outtype, buf, crd->crd_inject, ivlen, iv);
}
}
ivp = iv;
if (exf->reinit)
exf->reinit(sw->sw_kschedule, iv);
if (outtype == CRYPTO_BUF_MBUF) {
/* Find beginning of data */
m = m_getptr(m, crd->crd_skip, &k);
if (m == NULL)
return EINVAL;
i = crd->crd_len;
while (i > 0) {
/*
* If there's insufficient data at the end of
* an mbuf, we have to do some copying.
*/
if (m->m_len < k + blks && m->m_len != k) {
m_copydata(m, k, blks, blk);
/* Actual encryption/decryption */
if (exf->reinit) {
exf->encrypt(sw->sw_kschedule, blk);
} else if (crd->crd_flags & CRD_F_ENCRYPT) {
/* XOR with previous block */
for (j = 0; j < blks; j++)
blk[j] ^= ivp[j];
exf->encrypt(sw->sw_kschedule, blk);
/*
* Keep encrypted block for XOR'ing
* with next block
*/
bcopy(blk, iv, blks);
ivp = iv;
} else { /* decrypt */
/*
* Keep encrypted block for XOR'ing
* with next block
*/
if (ivp == iv)
bcopy(blk, piv, blks);
else
bcopy(blk, iv, blks);
exf->decrypt(sw->sw_kschedule, blk);
/* XOR with previous block */
for (j = 0; j < blks; j++)
blk[j] ^= ivp[j];
if (ivp == iv)
bcopy(piv, iv, blks);
else
ivp = iv;
}
/* Copy back decrypted block */
m_copyback(m, k, blks, blk);
/* Advance pointer */
m = m_getptr(m, k + blks, &k);
if (m == NULL)
return EINVAL;
i -= blks;
/* Could be done... */
if (i == 0)
break;
}
/* Skip possibly empty mbufs */
if (k == m->m_len) {
for (m = m->m_next; m && m->m_len == 0;
m = m->m_next)
;
k = 0;
}
/* Sanity check */
if (m == NULL)
return EINVAL;
/*
* Warning: idat may point to garbage here, but
* we only use it in the while() loop, only if
* there are indeed enough data.
*/
idat = mtod(m, unsigned char *) + k;
while (m->m_len >= k + blks && i > 0) {
if (exf->reinit) {
exf->encrypt(sw->sw_kschedule, idat);
} else if (crd->crd_flags & CRD_F_ENCRYPT) {
/* XOR with previous block/IV */
for (j = 0; j < blks; j++)
idat[j] ^= ivp[j];
exf->encrypt(sw->sw_kschedule, idat);
ivp = idat;
} else { /* decrypt */
/*
* Keep encrypted block to be used
* in next block's processing.
*/
if (ivp == iv)
bcopy(idat, piv, blks);
else
bcopy(idat, iv, blks);
exf->decrypt(sw->sw_kschedule, idat);
/* XOR with previous block/IV */
for (j = 0; j < blks; j++)
idat[j] ^= ivp[j];
if (ivp == iv)
bcopy(piv, iv, blks);
else
ivp = iv;
}
idat += blks;
k += blks;
i -= blks;
}
}
} else {
