f28776a369
This patch adds two new operations for the simple cipher that encrypts or decrypts a single block at a time. This will be the main interface after the existing block operations have moved over to the new block ciphers. It also adds the crypto_cipher type which is currently only used on the new operations but will be extended to setkey as well once existing users have been converted to use block ciphers where applicable. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
515 lines
13 KiB
C
515 lines
13 KiB
C
/*
|
|
* Cryptographic API.
|
|
*
|
|
* Cipher operations.
|
|
*
|
|
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
|
|
* Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the Free
|
|
* Software Foundation; either version 2 of the License, or (at your option)
|
|
* any later version.
|
|
*
|
|
*/
|
|
#include <linux/compiler.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
#include <asm/scatterlist.h>
|
|
#include "internal.h"
|
|
#include "scatterwalk.h"
|
|
|
|
static inline void xor_64(u8 *a, const u8 *b)
|
|
{
|
|
((u32 *)a)[0] ^= ((u32 *)b)[0];
|
|
((u32 *)a)[1] ^= ((u32 *)b)[1];
|
|
}
|
|
|
|
static inline void xor_128(u8 *a, const u8 *b)
|
|
{
|
|
((u32 *)a)[0] ^= ((u32 *)b)[0];
|
|
((u32 *)a)[1] ^= ((u32 *)b)[1];
|
|
((u32 *)a)[2] ^= ((u32 *)b)[2];
|
|
((u32 *)a)[3] ^= ((u32 *)b)[3];
|
|
}
|
|
|
|
static unsigned int crypt_slow(const struct cipher_desc *desc,
|
|
struct scatter_walk *in,
|
|
struct scatter_walk *out, unsigned int bsize)
|
|
{
|
|
unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);
|
|
u8 buffer[bsize * 2 + alignmask];
|
|
u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
|
|
u8 *dst = src + bsize;
|
|
unsigned int n;
|
|
|
|
n = scatterwalk_copychunks(src, in, bsize, 0);
|
|
scatterwalk_advance(in, n);
|
|
|
|
desc->prfn(desc, dst, src, bsize);
|
|
|
|
n = scatterwalk_copychunks(dst, out, bsize, 1);
|
|
scatterwalk_advance(out, n);
|
|
|
|
return bsize;
|
|
}
|
|
|
|
static inline unsigned int crypt_fast(const struct cipher_desc *desc,
|
|
struct scatter_walk *in,
|
|
struct scatter_walk *out,
|
|
unsigned int nbytes, u8 *tmp)
|
|
{
|
|
u8 *src, *dst;
|
|
|
|
src = in->data;
|
|
dst = scatterwalk_samebuf(in, out) ? src : out->data;
|
|
|
|
if (tmp) {
|
|
memcpy(tmp, in->data, nbytes);
|
|
src = tmp;
|
|
dst = tmp;
|
|
}
|
|
|
|
nbytes = desc->prfn(desc, dst, src, nbytes);
|
|
|
|
if (tmp)
|
|
memcpy(out->data, tmp, nbytes);
|
|
|
|
scatterwalk_advance(in, nbytes);
|
|
scatterwalk_advance(out, nbytes);
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
/*
|
|
* Generic encrypt/decrypt wrapper for ciphers, handles operations across
|
|
* multiple page boundaries by using temporary blocks. In user context,
|
|
* the kernel is given a chance to schedule us once per page.
|
|
*/
|
|
static int crypt(const struct cipher_desc *desc,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes)
|
|
{
|
|
struct scatter_walk walk_in, walk_out;
|
|
struct crypto_tfm *tfm = desc->tfm;
|
|
const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
|
|
unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
|
|
unsigned long buffer = 0;
|
|
|
|
if (!nbytes)
|
|
return 0;
|
|
|
|
if (nbytes % bsize) {
|
|
tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
|
|
return -EINVAL;
|
|
}
|
|
|
|
scatterwalk_start(&walk_in, src);
|
|
scatterwalk_start(&walk_out, dst);
|
|
|
|
for(;;) {
|
|
unsigned int n = nbytes;
|
|
u8 *tmp = NULL;
|
|
|
|
if (!scatterwalk_aligned(&walk_in, alignmask) ||
|
|
!scatterwalk_aligned(&walk_out, alignmask)) {
|
|
if (!buffer) {
|
|
buffer = __get_free_page(GFP_ATOMIC);
|
|
if (!buffer)
|
|
n = 0;
|
|
}
|
|
tmp = (u8 *)buffer;
|
|
}
|
|
|
|
scatterwalk_map(&walk_in, 0);
|
|
scatterwalk_map(&walk_out, 1);
|
|
|
|
n = scatterwalk_clamp(&walk_in, n);
|
|
n = scatterwalk_clamp(&walk_out, n);
|
|
|
|
if (likely(n >= bsize))
|
|
n = crypt_fast(desc, &walk_in, &walk_out, n, tmp);
|
|
else
|
|
n = crypt_slow(desc, &walk_in, &walk_out, bsize);
|
|
|
|
nbytes -= n;
|
|
|
|
scatterwalk_done(&walk_in, 0, nbytes);
|
|
scatterwalk_done(&walk_out, 1, nbytes);
|
|
|
|
if (!nbytes)
|
|
break;
|
|
|
|
crypto_yield(tfm->crt_flags);
|
|
}
|
|
|
|
if (buffer)
|
|
free_page(buffer);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crypt_iv_unaligned(struct cipher_desc *desc,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes)
|
|
{
|
|
struct crypto_tfm *tfm = desc->tfm;
|
|
unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
|
|
u8 *iv = desc->info;
|
|
|
|
if (unlikely(((unsigned long)iv & alignmask))) {
|
|
unsigned int ivsize = tfm->crt_cipher.cit_ivsize;
|
|
u8 buffer[ivsize + alignmask];
|
|
u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
|
|
int err;
|
|
|
|
desc->info = memcpy(tmp, iv, ivsize);
|
|
err = crypt(desc, dst, src, nbytes);
|
|
memcpy(iv, tmp, ivsize);
|
|
|
|
return err;
|
|
}
|
|
|
|
return crypt(desc, dst, src, nbytes);
|
|
}
|
|
|
|
static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
|
|
u8 *dst, const u8 *src,
|
|
unsigned int nbytes)
|
|
{
|
|
struct crypto_tfm *tfm = desc->tfm;
|
|
void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
|
|
int bsize = crypto_tfm_alg_blocksize(tfm);
|
|
|
|
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;
|
|
u8 *iv = desc->info;
|
|
unsigned int done = 0;
|
|
|
|
nbytes -= bsize;
|
|
|
|
do {
|
|
xor(iv, src);
|
|
fn(tfm, dst, iv);
|
|
memcpy(iv, dst, bsize);
|
|
|
|
src += bsize;
|
|
dst += bsize;
|
|
} while ((done += bsize) <= nbytes);
|
|
|
|
return done;
|
|
}
|
|
|
|
static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,
|
|
u8 *dst, const u8 *src,
|
|
unsigned int nbytes)
|
|
{
|
|
struct crypto_tfm *tfm = desc->tfm;
|
|
void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
|
|
int bsize = crypto_tfm_alg_blocksize(tfm);
|
|
unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);
|
|
|
|
u8 stack[src == dst ? bsize + alignmask : 0];
|
|
u8 *buf = (u8 *)ALIGN((unsigned long)stack, alignmask + 1);
|
|
u8 **dst_p = src == dst ? &buf : &dst;
|
|
|
|
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;
|
|
u8 *iv = desc->info;
|
|
unsigned int done = 0;
|
|
|
|
nbytes -= bsize;
|
|
|
|
do {
|
|
u8 *tmp_dst = *dst_p;
|
|
|
|
fn(tfm, tmp_dst, src);
|
|
xor(tmp_dst, iv);
|
|
memcpy(iv, src, bsize);
|
|
if (tmp_dst != dst)
|
|
memcpy(dst, tmp_dst, bsize);
|
|
|
|
src += bsize;
|
|
dst += bsize;
|
|
} while ((done += bsize) <= nbytes);
|
|
|
|
return done;
|
|
}
|
|
|
|
static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,
|
|
const u8 *src, unsigned int nbytes)
|
|
{
|
|
struct crypto_tfm *tfm = desc->tfm;
|
|
int bsize = crypto_tfm_alg_blocksize(tfm);
|
|
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;
|
|
unsigned int done = 0;
|
|
|
|
nbytes -= bsize;
|
|
|
|
do {
|
|
fn(tfm, dst, src);
|
|
|
|
src += bsize;
|
|
dst += bsize;
|
|
} while ((done += bsize) <= nbytes);
|
|
|
|
return done;
|
|
}
|
|
|
|
static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
|
|
{
|
|
struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
|
|
|
|
tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
|
|
if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
|
|
tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
|
|
return -EINVAL;
|
|
} else
|
|
return cia->cia_setkey(tfm, key, keylen);
|
|
}
|
|
|
|
static int ecb_encrypt(struct crypto_tfm *tfm,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src, unsigned int nbytes)
|
|
{
|
|
struct cipher_desc desc;
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
desc.tfm = tfm;
|
|
desc.crfn = cipher->cia_encrypt;
|
|
desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process;
|
|
|
|
return crypt(&desc, dst, src, nbytes);
|
|
}
|
|
|
|
static int ecb_decrypt(struct crypto_tfm *tfm,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes)
|
|
{
|
|
struct cipher_desc desc;
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
desc.tfm = tfm;
|
|
desc.crfn = cipher->cia_decrypt;
|
|
desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process;
|
|
|
|
return crypt(&desc, dst, src, nbytes);
|
|
}
|
|
|
|
static int cbc_encrypt(struct crypto_tfm *tfm,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes)
|
|
{
|
|
struct cipher_desc desc;
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
desc.tfm = tfm;
|
|
desc.crfn = cipher->cia_encrypt;
|
|
desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
|
|
desc.info = tfm->crt_cipher.cit_iv;
|
|
|
|
return crypt(&desc, dst, src, nbytes);
|
|
}
|
|
|
|
static int cbc_encrypt_iv(struct crypto_tfm *tfm,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes, u8 *iv)
|
|
{
|
|
struct cipher_desc desc;
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
desc.tfm = tfm;
|
|
desc.crfn = cipher->cia_encrypt;
|
|
desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
|
|
desc.info = iv;
|
|
|
|
return crypt_iv_unaligned(&desc, dst, src, nbytes);
|
|
}
|
|
|
|
static int cbc_decrypt(struct crypto_tfm *tfm,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes)
|
|
{
|
|
struct cipher_desc desc;
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
desc.tfm = tfm;
|
|
desc.crfn = cipher->cia_decrypt;
|
|
desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
|
|
desc.info = tfm->crt_cipher.cit_iv;
|
|
|
|
return crypt(&desc, dst, src, nbytes);
|
|
}
|
|
|
|
static int cbc_decrypt_iv(struct crypto_tfm *tfm,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes, u8 *iv)
|
|
{
|
|
struct cipher_desc desc;
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
desc.tfm = tfm;
|
|
desc.crfn = cipher->cia_decrypt;
|
|
desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
|
|
desc.info = iv;
|
|
|
|
return crypt_iv_unaligned(&desc, dst, src, nbytes);
|
|
}
|
|
|
|
static int nocrypt(struct crypto_tfm *tfm,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static int nocrypt_iv(struct crypto_tfm *tfm,
|
|
struct scatterlist *dst,
|
|
struct scatterlist *src,
|
|
unsigned int nbytes, u8 *iv)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
|
|
{
|
|
u32 mode = flags & CRYPTO_TFM_MODE_MASK;
|
|
tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
|
|
return 0;
|
|
}
|
|
|
|
static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
|
|
const u8 *),
|
|
struct crypto_tfm *tfm,
|
|
u8 *dst, const u8 *src)
|
|
{
|
|
unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
|
|
unsigned int size = crypto_tfm_alg_blocksize(tfm);
|
|
u8 buffer[size + alignmask];
|
|
u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
|
|
|
|
memcpy(tmp, src, size);
|
|
fn(tfm, tmp, tmp);
|
|
memcpy(dst, tmp, size);
|
|
}
|
|
|
|
static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
|
|
u8 *dst, const u8 *src)
|
|
{
|
|
unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
|
|
cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
|
|
return;
|
|
}
|
|
|
|
cipher->cia_encrypt(tfm, dst, src);
|
|
}
|
|
|
|
static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
|
|
u8 *dst, const u8 *src)
|
|
{
|
|
unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
|
|
cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
|
|
return;
|
|
}
|
|
|
|
cipher->cia_decrypt(tfm, dst, src);
|
|
}
|
|
|
|
int crypto_init_cipher_ops(struct crypto_tfm *tfm)
|
|
{
|
|
int ret = 0;
|
|
struct cipher_tfm *ops = &tfm->crt_cipher;
|
|
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
|
|
|
|
ops->cit_setkey = setkey;
|
|
ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
|
|
cipher_encrypt_unaligned : cipher->cia_encrypt;
|
|
ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
|
|
cipher_decrypt_unaligned : cipher->cia_decrypt;
|
|
|
|
switch (tfm->crt_cipher.cit_mode) {
|
|
case CRYPTO_TFM_MODE_ECB:
|
|
ops->cit_encrypt = ecb_encrypt;
|
|
ops->cit_decrypt = ecb_decrypt;
|
|
ops->cit_encrypt_iv = nocrypt_iv;
|
|
ops->cit_decrypt_iv = nocrypt_iv;
|
|
break;
|
|
|
|
case CRYPTO_TFM_MODE_CBC:
|
|
ops->cit_encrypt = cbc_encrypt;
|
|
ops->cit_decrypt = cbc_decrypt;
|
|
ops->cit_encrypt_iv = cbc_encrypt_iv;
|
|
ops->cit_decrypt_iv = cbc_decrypt_iv;
|
|
break;
|
|
|
|
case CRYPTO_TFM_MODE_CFB:
|
|
ops->cit_encrypt = nocrypt;
|
|
ops->cit_decrypt = nocrypt;
|
|
ops->cit_encrypt_iv = nocrypt_iv;
|
|
ops->cit_decrypt_iv = nocrypt_iv;
|
|
break;
|
|
|
|
case CRYPTO_TFM_MODE_CTR:
|
|
ops->cit_encrypt = nocrypt;
|
|
ops->cit_decrypt = nocrypt;
|
|
ops->cit_encrypt_iv = nocrypt_iv;
|
|
ops->cit_decrypt_iv = nocrypt_iv;
|
|
break;
|
|
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
|
|
unsigned long align;
|
|
unsigned long addr;
|
|
|
|
switch (crypto_tfm_alg_blocksize(tfm)) {
|
|
case 8:
|
|
ops->cit_xor_block = xor_64;
|
|
break;
|
|
|
|
case 16:
|
|
ops->cit_xor_block = xor_128;
|
|
break;
|
|
|
|
default:
|
|
printk(KERN_WARNING "%s: block size %u not supported\n",
|
|
crypto_tfm_alg_name(tfm),
|
|
crypto_tfm_alg_blocksize(tfm));
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
|
|
align = crypto_tfm_alg_alignmask(tfm) + 1;
|
|
addr = (unsigned long)crypto_tfm_ctx(tfm);
|
|
addr = ALIGN(addr, align);
|
|
addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
|
|
ops->cit_iv = (void *)addr;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
|
|
{
|
|
}
|