458 lines
11 KiB
C
458 lines
11 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);
|
|
}
|
|
|
|
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)(void *, u8 *, const u8 *) = desc->crfn;
|
|
u8 *iv = desc->info;
|
|
unsigned int done = 0;
|
|
|
|
do {
|
|
xor(iv, src);
|
|
fn(crypto_tfm_ctx(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);
|
|
|
|
u8 stack[src == dst ? bsize : 0];
|
|
u8 *buf = stack;
|
|
u8 **dst_p = src == dst ? &buf : &dst;
|
|
|
|
void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
|
|
u8 *iv = desc->info;
|
|
unsigned int done = 0;
|
|
|
|
do {
|
|
u8 *tmp_dst = *dst_p;
|
|
|
|
fn(crypto_tfm_ctx(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)(void *, u8 *, const u8 *) = desc->crfn;
|
|
unsigned int done = 0;
|
|
|
|
do {
|
|
fn(crypto_tfm_ctx(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;
|
|
|
|
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(crypto_tfm_ctx(tfm), key, keylen,
|
|
&tfm->crt_flags);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
int crypto_init_cipher_ops(struct crypto_tfm *tfm)
|
|
{
|
|
int ret = 0;
|
|
struct cipher_tfm *ops = &tfm->crt_cipher;
|
|
|
|
ops->cit_setkey = setkey;
|
|
|
|
switch (tfm->crt_cipher.cit_mode) {
|
|
case CRYPTO_TFM_MODE_ECB:
|
|
ops->cit_encrypt = ecb_encrypt;
|
|
ops->cit_decrypt = ecb_decrypt;
|
|
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)
|
|
{
|
|
}
|