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crypto: cbc - Convert to skcipher

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This patch converts cbc over to the skcipher interface.  It also
rearranges the code to allow it to be reused by drivers.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2016-11-22 20:08:39 +08:00
parent da40e7a4ba
commit 79c65d179a
1 changed files with 138 additions and 104 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

240
crypto/cbc.c
View file

@ -10,42 +10,39 @@
* *
*/ */
#include <crypto/algapi.h> #include <crypto/internal/skcipher.h>
#include <linux/err.h> #include <linux/err.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/log2.h> #include <linux/log2.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/slab.h> #include <linux/slab.h>
struct crypto_cbc_ctx { struct crypto_cbc_ctx {
struct crypto_cipher *child; struct crypto_cipher *child;
}; };
static int crypto_cbc_setkey(struct crypto_tfm *parent, const u8 *key, static int crypto_cbc_setkey(struct crypto_skcipher *parent, const u8 *key,
unsigned int keylen) unsigned int keylen)
{ {
struct crypto_cbc_ctx *ctx = crypto_tfm_ctx(parent); struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(parent);
struct crypto_cipher *child = ctx->child; struct crypto_cipher *child = ctx->child;
int err; int err;
crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) & crypto_cipher_set_flags(child, crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK); CRYPTO_TFM_REQ_MASK);
err = crypto_cipher_setkey(child, key, keylen); err = crypto_cipher_setkey(child, key, keylen);
crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) & crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(child) &
CRYPTO_TFM_RES_MASK); CRYPTO_TFM_RES_MASK);
return err; return err;
} }
static int crypto_cbc_encrypt_segment(struct blkcipher_desc *desc, static inline int crypto_cbc_encrypt_segment(
struct blkcipher_walk *walk, struct skcipher_walk *walk, struct crypto_skcipher *tfm,
struct crypto_cipher *tfm) void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))
{ {
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = unsigned int bsize = crypto_skcipher_blocksize(tfm);
crypto_cipher_alg(tfm)->cia_encrypt;
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes; unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr; u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr; u8 *dst = walk->dst.virt.addr;
@ -53,7 +50,7 @@ static int crypto_cbc_encrypt_segment(struct blkcipher_desc *desc,
do { do {
crypto_xor(iv, src, bsize); crypto_xor(iv, src, bsize);
fn(crypto_cipher_tfm(tfm), dst, iv); fn(tfm, iv, dst);
memcpy(iv, dst, bsize); memcpy(iv, dst, bsize);
src += bsize; src += bsize;
@ -63,20 +60,18 @@ static int crypto_cbc_encrypt_segment(struct blkcipher_desc *desc,
return nbytes; return nbytes;
} }
static int crypto_cbc_encrypt_inplace(struct blkcipher_desc *desc, static inline int crypto_cbc_encrypt_inplace(
struct blkcipher_walk *walk, struct skcipher_walk *walk, struct crypto_skcipher *tfm,
struct crypto_cipher *tfm) void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))
{ {
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = unsigned int bsize = crypto_skcipher_blocksize(tfm);
crypto_cipher_alg(tfm)->cia_encrypt;
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes; unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr; u8 *src = walk->src.virt.addr;
u8 *iv = walk->iv; u8 *iv = walk->iv;
do { do {
crypto_xor(src, iv, bsize); crypto_xor(src, iv, bsize);
fn(crypto_cipher_tfm(tfm), src, src); fn(tfm, src, src);
iv = src; iv = src;
src += bsize; src += bsize;
@ -87,44 +82,52 @@ static int crypto_cbc_encrypt_inplace(struct blkcipher_desc *desc,
return nbytes; return nbytes;
} }
static int crypto_cbc_encrypt(struct blkcipher_desc *desc, static inline int crypto_cbc_encrypt_walk(struct skcipher_request *req,
struct scatterlist *dst, struct scatterlist *src, void (*fn)(struct crypto_skcipher *,
unsigned int nbytes) const u8 *, u8 *))
{ {
struct blkcipher_walk walk; struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_blkcipher *tfm = desc->tfm; struct skcipher_walk walk;
struct crypto_cbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
struct crypto_cipher *child = ctx->child;
int err; int err;
blkcipher_walk_init(&walk, dst, src, nbytes); err = skcipher_walk_virt(&walk, req, false);
err = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) { while (walk.nbytes) {
if (walk.src.virt.addr == walk.dst.virt.addr) if (walk.src.virt.addr == walk.dst.virt.addr)
nbytes = crypto_cbc_encrypt_inplace(desc, &walk, child); err = crypto_cbc_encrypt_inplace(&walk, tfm, fn);
else else
nbytes = crypto_cbc_encrypt_segment(desc, &walk, child); err = crypto_cbc_encrypt_segment(&walk, tfm, fn);
err = blkcipher_walk_done(desc, &walk, nbytes); err = skcipher_walk_done(&walk, err);
} }
return err; return err;
} }
static int crypto_cbc_decrypt_segment(struct blkcipher_desc *desc, static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
struct blkcipher_walk *walk, const u8 *src, u8 *dst)
struct crypto_cipher *tfm)
{ {
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_cipher_alg(tfm)->cia_decrypt;
int bsize = crypto_cipher_blocksize(tfm); crypto_cipher_encrypt_one(ctx->child, dst, src);
}
static int crypto_cbc_encrypt(struct skcipher_request *req)
{
return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
}
static inline int crypto_cbc_decrypt_segment(
struct skcipher_walk *walk, struct crypto_skcipher *tfm,
void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))
{
unsigned int bsize = crypto_skcipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes; unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr; u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr; u8 *dst = walk->dst.virt.addr;
u8 *iv = walk->iv; u8 *iv = walk->iv;
do { do {
fn(crypto_cipher_tfm(tfm), dst, src); fn(tfm, src, dst);
crypto_xor(dst, iv, bsize); crypto_xor(dst, iv, bsize);
iv = src; iv = src;
@ -137,13 +140,11 @@ static int crypto_cbc_decrypt_segment(struct blkcipher_desc *desc,
return nbytes; return nbytes;
} }
static int crypto_cbc_decrypt_inplace(struct blkcipher_desc *desc, static inline int crypto_cbc_decrypt_inplace(
struct blkcipher_walk *walk, struct skcipher_walk *walk, struct crypto_skcipher *tfm,
struct crypto_cipher *tfm) void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))
{ {
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = unsigned int bsize = crypto_skcipher_blocksize(tfm);
crypto_cipher_alg(tfm)->cia_decrypt;
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes; unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr; u8 *src = walk->src.virt.addr;
u8 last_iv[bsize]; u8 last_iv[bsize];
@ -153,7 +154,7 @@ static int crypto_cbc_decrypt_inplace(struct blkcipher_desc *desc,
memcpy(last_iv, src, bsize); memcpy(last_iv, src, bsize);
for (;;) { for (;;) {
fn(crypto_cipher_tfm(tfm), src, src); fn(tfm, src, src);
if ((nbytes -= bsize) < bsize) if ((nbytes -= bsize) < bsize)
break; break;
crypto_xor(src, src - bsize, bsize); crypto_xor(src, src - bsize, bsize);
@ -166,35 +167,46 @@ static int crypto_cbc_decrypt_inplace(struct blkcipher_desc *desc,
return nbytes; return nbytes;
} }
static int crypto_cbc_decrypt(struct blkcipher_desc *desc, static inline int crypto_cbc_decrypt_blocks(
struct scatterlist *dst, struct scatterlist *src, struct skcipher_walk *walk, struct crypto_skcipher *tfm,
unsigned int nbytes) void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))
{ {
struct blkcipher_walk walk; if (walk->src.virt.addr == walk->dst.virt.addr)
struct crypto_blkcipher *tfm = desc->tfm; return crypto_cbc_decrypt_inplace(walk, tfm, fn);
struct crypto_cbc_ctx *ctx = crypto_blkcipher_ctx(tfm); else
struct crypto_cipher *child = ctx->child; return crypto_cbc_decrypt_segment(walk, tfm, fn);
}
static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
const u8 *src, u8 *dst)
{
struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_cipher_decrypt_one(ctx->child, dst, src);
}
static int crypto_cbc_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct skcipher_walk walk;
int err; int err;
blkcipher_walk_init(&walk, dst, src, nbytes); err = skcipher_walk_virt(&walk, req, false);
err = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) { while (walk.nbytes) {
if (walk.src.virt.addr == walk.dst.virt.addr) err = crypto_cbc_decrypt_blocks(&walk, tfm,
nbytes = crypto_cbc_decrypt_inplace(desc, &walk, child); crypto_cbc_decrypt_one);
else err = skcipher_walk_done(&walk, err);
nbytes = crypto_cbc_decrypt_segment(desc, &walk, child);
err = blkcipher_walk_done(desc, &walk, nbytes);
} }
return err; return err;
} }
static int crypto_cbc_init_tfm(struct crypto_tfm *tfm) static int crypto_cbc_init_tfm(struct crypto_skcipher *tfm)
{ {
struct crypto_instance *inst = (void *)tfm->__crt_alg; struct skcipher_instance *inst = skcipher_alg_instance(tfm);
struct crypto_spawn *spawn = crypto_instance_ctx(inst); struct crypto_spawn *spawn = skcipher_instance_ctx(inst);
struct crypto_cbc_ctx *ctx = crypto_tfm_ctx(tfm); struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_cipher *cipher; struct crypto_cipher *cipher;
cipher = crypto_spawn_cipher(spawn); cipher = crypto_spawn_cipher(spawn);
@ -205,72 +217,94 @@ static int crypto_cbc_init_tfm(struct crypto_tfm *tfm)
return 0; return 0;
} }
static void crypto_cbc_exit_tfm(struct crypto_tfm *tfm) static void crypto_cbc_exit_tfm(struct crypto_skcipher *tfm)
{ {
struct crypto_cbc_ctx *ctx = crypto_tfm_ctx(tfm); struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_free_cipher(ctx->child); crypto_free_cipher(ctx->child);
} }
static struct crypto_instance *crypto_cbc_alloc(struct rtattr **tb) static void crypto_cbc_free(struct skcipher_instance *inst)
{ {
struct crypto_instance *inst; crypto_drop_skcipher(skcipher_instance_ctx(inst));
kfree(inst);
}
static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct skcipher_instance *inst;
struct crypto_spawn *spawn;
struct crypto_alg *alg; struct crypto_alg *alg;
int err; int err;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER); err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER);
if (err) if (err)
return ERR_PTR(err); return err;
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return -ENOMEM;
alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
CRYPTO_ALG_TYPE_MASK); CRYPTO_ALG_TYPE_MASK);
err = PTR_ERR(alg);
if (IS_ERR(alg)) if (IS_ERR(alg))
return ERR_CAST(alg); goto err_free_inst;
inst = ERR_PTR(-EINVAL); spawn = skcipher_instance_ctx(inst);
err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst),
CRYPTO_ALG_TYPE_MASK);
crypto_mod_put(alg);
if (err)
goto err_free_inst;
err = crypto_inst_setname(skcipher_crypto_instance(inst), "cbc", alg);
if (err)
goto err_drop_spawn;
err = -EINVAL;
if (!is_power_of_2(alg->cra_blocksize)) if (!is_power_of_2(alg->cra_blocksize))
goto out_put_alg; goto err_drop_spawn;
inst = crypto_alloc_instance("cbc", alg); inst->alg.base.cra_priority = alg->cra_priority;
if (IS_ERR(inst)) inst->alg.base.cra_blocksize = alg->cra_blocksize;
goto out_put_alg; inst->alg.base.cra_alignmask = alg->cra_alignmask;
inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
inst->alg.cra_priority = alg->cra_priority;
inst->alg.cra_blocksize = alg->cra_blocksize;
inst->alg.cra_alignmask = alg->cra_alignmask;
inst->alg.cra_type = &crypto_blkcipher_type;
/* We access the data as u32s when xoring. */ /* We access the data as u32s when xoring. */
inst->alg.cra_alignmask |= __alignof__(u32) - 1; inst->alg.base.cra_alignmask |= __alignof__(u32) - 1;
inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize; inst->alg.ivsize = alg->cra_blocksize;
inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize; inst->alg.min_keysize = alg->cra_cipher.cia_min_keysize;
inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize; inst->alg.max_keysize = alg->cra_cipher.cia_max_keysize;
inst->alg.cra_ctxsize = sizeof(struct crypto_cbc_ctx); inst->alg.base.cra_ctxsize = sizeof(struct crypto_cbc_ctx);
inst->alg.cra_init = crypto_cbc_init_tfm; inst->alg.init = crypto_cbc_init_tfm;
inst->alg.cra_exit = crypto_cbc_exit_tfm; inst->alg.exit = crypto_cbc_exit_tfm;
inst->alg.cra_blkcipher.setkey = crypto_cbc_setkey; inst->alg.setkey = crypto_cbc_setkey;
inst->alg.cra_blkcipher.encrypt = crypto_cbc_encrypt; inst->alg.encrypt = crypto_cbc_encrypt;
inst->alg.cra_blkcipher.decrypt = crypto_cbc_decrypt; inst->alg.decrypt = crypto_cbc_decrypt;
out_put_alg: inst->free = crypto_cbc_free;
crypto_mod_put(alg);
return inst;
}
static void crypto_cbc_free(struct crypto_instance *inst) err = skcipher_register_instance(tmpl, inst);
{ if (err)
crypto_drop_spawn(crypto_instance_ctx(inst)); goto err_drop_spawn;
out:
return err;
err_drop_spawn:
crypto_drop_spawn(spawn);
err_free_inst:
kfree(inst); kfree(inst);
goto out;
} }
static struct crypto_template crypto_cbc_tmpl = { static struct crypto_template crypto_cbc_tmpl = {
.name = "cbc", .name = "cbc",
.alloc = crypto_cbc_alloc, .create = crypto_cbc_create,
.free = crypto_cbc_free,
.module = THIS_MODULE, .module = THIS_MODULE,
}; };