static void update(struct crypto_tfm *tfm,
struct scatterlist *sg, unsigned int nsg)
{
unsigned int i;
for (i = 0; i < nsg; i++) {
#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24))
struct page *pg = sg[i].page;
#else
struct page *pg = sg_page(&sg[i]);
#endif
unsigned int offset = sg[i].offset;
unsigned int l = sg[i].length;
do {
unsigned int bytes_from_page = min(l, ((unsigned int)
(PAGE_SIZE)) -
offset);
char *p = crypto_kmap(pg, 0) + offset;
tfm->__crt_alg->cra_digest.dia_update
(crypto_tfm_ctx(tfm), p,
bytes_from_page);
crypto_kunmap(p, 0);
crypto_yield(tfm);
offset = 0;
pg++;
l -= bytes_from_page;
} while (l > 0);
}
}
static int update2(struct hash_desc *desc,
struct scatterlist *sg, unsigned int nbytes)
{
struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
if (!nbytes)
return 0;
for (;;) {
struct page *pg = sg_page(sg);
unsigned int offset = sg->offset;
unsigned int l = sg->length;
if (unlikely(l > nbytes))
l = nbytes;
nbytes -= l;
do {
unsigned int bytes_from_page = min(l, ((unsigned int)
(PAGE_SIZE)) -
offset);
char *src = crypto_kmap(pg, 0);
char *p = src + offset;
if (unlikely(offset & alignmask)) {
unsigned int bytes =
alignmask + 1 - (offset & alignmask);
bytes = min(bytes, bytes_from_page);
tfm->__crt_alg->cra_digest.dia_update(tfm, p,
bytes);
p += bytes;
bytes_from_page -= bytes;
l -= bytes;
}
tfm->__crt_alg->cra_digest.dia_update(tfm, p,
bytes_from_page);
crypto_kunmap(src, 0);
crypto_yield(desc->flags);
offset = 0;
pg++;
l -= bytes_from_page;
} while (l > 0);
if (!nbytes)
break;
sg = scatterwalk_sg_next(sg);
}
return 0;
}
/*
* Do not call this unless the total length of all of the fragments
* has been verified as multiple of the block size.
*/
int scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
size_t nbytes, int out)
{
if (buf != walk->data) {
while (nbytes > walk->len_this_page) {
memcpy_dir(buf, walk->data, walk->len_this_page, out);
buf += walk->len_this_page;
nbytes -= walk->len_this_page;
crypto_kunmap(walk->data, out);
scatterwalk_pagedone(walk, out, 1);
scatterwalk_map(walk, out);
}
memcpy_dir(buf, walk->data, nbytes, out);
}
walk->offset += nbytes;
walk->len_this_page -= nbytes;
walk->len_this_segment -= nbytes;
return 0;
}
void scatterwalk_done(struct scatter_walk *walk, int out, int more)
{
crypto_kunmap(walk->data, out);
if (walk->len_this_page == 0 || !more)
scatterwalk_pagedone(walk, out, more);
}
void crypto_xcbc_update(struct crypto_tfm *tfm, struct scatterlist *sg, unsigned int nsg)
{
struct xcbc_ops *ops = (struct xcbc_ops*)tfm->crt_cipher.cit_xcbc_block;
const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
unsigned int i;
if (!(tfm->crt_cipher.cit_mode & CRYPTO_TFM_MODE_CBC))
return;
for(i = 0; i < nsg; i++) {
struct page *pg = sg[i].page;
unsigned int offset = sg[i].offset;
unsigned int slen = sg[i].length;
while (slen > 0) {
unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
char *p = crypto_kmap(pg, 0) + offset;
/* checking the data can fill the block */
if ((ops->len + len) <= bsize) {
memcpy(ops->prev + ops->len, p, len);
ops->len += len;
slen -= len;
/* checking the rest of the page */
if (len + offset >= PAGE_SIZE) {
offset = 0;
pg++;
} else
offset += len;
crypto_kunmap(p, 0);
crypto_yield(tfm);
continue;
}
/* filling ops->prev with new data and encrypting it */
memcpy(ops->prev + ops->len, p, bsize - ops->len);
len -= bsize - ops->len;
p += bsize - ops->len;
tfm->crt_u.cipher.cit_xor_block(tfm->crt_cipher.cit_iv,
ops->prev);
tfm->__crt_alg->cra_cipher.cia_encrypt(
crypto_tfm_ctx(tfm), tfm->crt_cipher.cit_iv,
tfm->crt_cipher.cit_iv);
/* clearing the length */
ops->len = 0;
/* encrypting the rest of data */
while (len > bsize) {
tfm->crt_u.cipher.cit_xor_block(tfm->crt_cipher.cit_iv, p);
tfm->__crt_alg->cra_cipher.cia_encrypt(
crypto_tfm_ctx(tfm), tfm->crt_cipher.cit_iv,
tfm->crt_cipher.cit_iv);
p += bsize;
len -= bsize;
}
/* keeping the surplus of blocksize */
if (len) {
memcpy(ops->prev, p, len);
ops->len = len;
}
crypto_kunmap(p, 0);
crypto_yield(tfm);
slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
offset = 0;
pg++;
}
}
}