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yaml
---
r: 4171
b: refs/heads/master
c: c774e93
h: refs/heads/master
i:
  4169: b63ce35
  4167: 6242922
v: v3
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Herbert Xu authored and David S. Miller committed Jul 6, 2005
1 parent 78fb991 commit d26f842
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Showing 4 changed files with 162 additions and 96 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 8279dd748f9704b811e528b31304e2fab026abc5
refs/heads/master: c774e93e2152d0be2612739418689e6e6400f4eb
246 changes: 156 additions & 90 deletions trunk/crypto/cipher.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
* 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
Expand All @@ -22,9 +23,13 @@
#include "internal.h"
#include "scatterwalk.h"

typedef void (cryptfn_t)(void *, u8 *, const u8 *);
typedef void (procfn_t)(struct crypto_tfm *, u8 *,
u8*, cryptfn_t, void *);
struct cipher_desc {
struct crypto_tfm *tfm;
void (*crfn)(void *ctx, u8 *dst, const u8 *src);
unsigned int (*prfn)(const struct cipher_desc *desc, u8 *dst,
const u8 *src, unsigned int nbytes);
void *info;
};

static inline void xor_64(u8 *a, const u8 *b)
{
Expand All @@ -39,63 +44,57 @@ static inline void xor_128(u8 *a, const u8 *b)
((u32 *)a)[2] ^= ((u32 *)b)[2];
((u32 *)a)[3] ^= ((u32 *)b)[3];
}

static inline void *prepare_src(struct scatter_walk *walk, int bsize,
void *tmp, int in_place)

static unsigned int crypt_slow(const struct cipher_desc *desc,
struct scatter_walk *in,
struct scatter_walk *out, unsigned int bsize)
{
void *src = walk->data;
int n = bsize;
u8 src[bsize];
u8 dst[bsize];
unsigned int n;

if (unlikely(scatterwalk_across_pages(walk, bsize))) {
src = tmp;
n = scatterwalk_copychunks(src, walk, bsize, 0);
}
scatterwalk_advance(walk, n);
return src;
}
n = scatterwalk_copychunks(src, in, bsize, 0);
scatterwalk_advance(in, n);

static inline void *prepare_dst(struct scatter_walk *walk, int bsize,
void *tmp, int in_place)
{
void *dst = walk->data;
desc->prfn(desc, dst, src, bsize);

if (unlikely(scatterwalk_across_pages(walk, bsize)) || in_place)
dst = tmp;
return dst;
}
n = scatterwalk_copychunks(dst, out, bsize, 1);
scatterwalk_advance(out, n);

static inline void complete_src(struct scatter_walk *walk, int bsize,
void *src, int in_place)
{
return bsize;
}

static inline void complete_dst(struct scatter_walk *walk, int bsize,
void *dst, int in_place)
static inline unsigned int crypt_fast(const struct cipher_desc *desc,
struct scatter_walk *in,
struct scatter_walk *out,
unsigned int nbytes)
{
int n = bsize;
u8 *src, *dst;

src = in->data;
dst = scatterwalk_samebuf(in, out) ? src : out->data;

nbytes = desc->prfn(desc, dst, src, nbytes);

scatterwalk_advance(in, nbytes);
scatterwalk_advance(out, nbytes);

if (unlikely(scatterwalk_across_pages(walk, bsize)))
n = scatterwalk_copychunks(dst, walk, bsize, 1);
else if (in_place)
memcpy(walk->data, dst, bsize);
scatterwalk_advance(walk, n);
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 block.
* the kernel is given a chance to schedule us once per page.
*/
static int crypt(struct crypto_tfm *tfm,
static int crypt(const struct cipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src,
unsigned int nbytes, cryptfn_t crfn,
procfn_t prfn, void *info)
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);
u8 tmp_src[bsize];
u8 tmp_dst[bsize];

if (!nbytes)
return 0;
Expand All @@ -109,29 +108,20 @@ static int crypt(struct crypto_tfm *tfm,
scatterwalk_start(&walk_out, dst);

for(;;) {
u8 *src_p, *dst_p;
int in_place;
unsigned int n;

scatterwalk_map(&walk_in, 0);
scatterwalk_map(&walk_out, 1);

in_place = scatterwalk_samebuf(&walk_in, &walk_out);
n = scatterwalk_clamp(&walk_in, nbytes);
n = scatterwalk_clamp(&walk_out, n);

do {
src_p = prepare_src(&walk_in, bsize, tmp_src,
in_place);
dst_p = prepare_dst(&walk_out, bsize, tmp_dst,
in_place);
if (likely(n >= bsize))
n = crypt_fast(desc, &walk_in, &walk_out, n);
else
n = crypt_slow(desc, &walk_in, &walk_out, bsize);

prfn(tfm, dst_p, src_p, crfn, info);

complete_src(&walk_in, bsize, src_p, in_place);
complete_dst(&walk_out, bsize, dst_p, in_place);

nbytes -= bsize;
} while (nbytes &&
!scatterwalk_across_pages(&walk_in, bsize) &&
!scatterwalk_across_pages(&walk_out, bsize));
nbytes -= n;

scatterwalk_done(&walk_in, 0, nbytes);
scatterwalk_done(&walk_out, 1, nbytes);
Expand All @@ -143,30 +133,78 @@ static int crypt(struct crypto_tfm *tfm,
}
}

static void cbc_process_encrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src,
cryptfn_t fn, void *info)
static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
u8 *dst, const u8 *src,
unsigned int nbytes)
{
u8 *iv = info;
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);

tfm->crt_u.cipher.cit_xor_block(iv, src);
fn(crypto_tfm_ctx(tfm), dst, iv);
memcpy(iv, dst, crypto_tfm_alg_blocksize(tfm));
src += bsize;
dst += bsize;
} while ((done += bsize) < nbytes);

return done;
}

static void cbc_process_decrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src,
cryptfn_t fn, void *info)
static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,
u8 *dst, const u8 *src,
unsigned int nbytes)
{
u8 *iv = info;
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), dst, src);
tfm->crt_u.cipher.cit_xor_block(dst, iv);
memcpy(iv, src, crypto_tfm_alg_blocksize(tfm));
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 void ecb_process(struct crypto_tfm *tfm, u8 *dst, u8 *src,
cryptfn_t fn, void *info)
static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,
const u8 *src, unsigned int nbytes)
{
fn(crypto_tfm_ctx(tfm), dst, src);
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)
Expand All @@ -185,59 +223,87 @@ static int ecb_encrypt(struct crypto_tfm *tfm,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
return crypt(tfm, dst, src, nbytes,
tfm->__crt_alg->cra_cipher.cia_encrypt,
ecb_process, NULL);
struct cipher_desc desc;

desc.tfm = tfm;
desc.crfn = tfm->__crt_alg->cra_cipher.cia_encrypt;
desc.prfn = 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)
{
return crypt(tfm, dst, src, nbytes,
tfm->__crt_alg->cra_cipher.cia_decrypt,
ecb_process, NULL);
struct cipher_desc desc;

desc.tfm = tfm;
desc.crfn = tfm->__crt_alg->cra_cipher.cia_decrypt;
desc.prfn = 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)
{
return crypt(tfm, dst, src, nbytes,
tfm->__crt_alg->cra_cipher.cia_encrypt,
cbc_process_encrypt, tfm->crt_cipher.cit_iv);
struct cipher_desc desc;

desc.tfm = tfm;
desc.crfn = tfm->__crt_alg->cra_cipher.cia_encrypt;
desc.prfn = 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)
{
return crypt(tfm, dst, src, nbytes,
tfm->__crt_alg->cra_cipher.cia_encrypt,
cbc_process_encrypt, iv);
struct cipher_desc desc;

desc.tfm = tfm;
desc.crfn = tfm->__crt_alg->cra_cipher.cia_encrypt;
desc.prfn = cbc_process_encrypt;
desc.info = iv;

return crypt(&desc, dst, src, nbytes);
}

static int cbc_decrypt(struct crypto_tfm *tfm,
struct scatterlist *dst,
struct scatterlist *src,
unsigned int nbytes)
{
return crypt(tfm, dst, src, nbytes,
tfm->__crt_alg->cra_cipher.cia_decrypt,
cbc_process_decrypt, tfm->crt_cipher.cit_iv);
struct cipher_desc desc;

desc.tfm = tfm;
desc.crfn = tfm->__crt_alg->cra_cipher.cia_decrypt;
desc.prfn = 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)
{
return crypt(tfm, dst, src, nbytes,
tfm->__crt_alg->cra_cipher.cia_decrypt,
cbc_process_decrypt, iv);
struct cipher_desc desc;

desc.tfm = tfm;
desc.crfn = tfm->__crt_alg->cra_cipher.cia_decrypt;
desc.prfn = cbc_process_decrypt;
desc.info = iv;

return crypt(&desc, dst, src, nbytes);
}

static int nocrypt(struct crypto_tfm *tfm,
Expand Down
4 changes: 2 additions & 2 deletions trunk/crypto/scatterwalk.c
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Original file line number Diff line number Diff line change
Expand Up @@ -100,15 +100,15 @@ void scatterwalk_done(struct scatter_walk *walk, int out, int more)
int scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
size_t nbytes, int out)
{
do {
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;

scatterwalk_unmap(walk, out);
scatterwalk_pagedone(walk, out, 1);
scatterwalk_map(walk, out);
} while (nbytes > walk->len_this_page);
}

memcpy_dir(buf, walk->data, nbytes, out);
return nbytes;
Expand Down
6 changes: 3 additions & 3 deletions trunk/crypto/scatterwalk.h
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Original file line number Diff line number Diff line change
Expand Up @@ -40,10 +40,10 @@ static inline int scatterwalk_samebuf(struct scatter_walk *walk_in,
walk_in->offset == walk_out->offset;
}

static inline int scatterwalk_across_pages(struct scatter_walk *walk,
unsigned int nbytes)
static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
unsigned int nbytes)
{
return nbytes > walk->len_this_page;
return nbytes > walk->len_this_page ? walk->len_this_page : nbytes;
}

static inline void scatterwalk_advance(struct scatter_walk *walk,
Expand Down

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