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crypto: xts - prefix function and struct names with "xts"
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Overly-generic names can cause problems like naming collisions,
confusing crash reports, and reduced grep-ability.  E.g. see
commit d099ea6 ("crypto - Avoid free() namespace collision").

Clean this up for the xts template by prefixing the names with "xts_".

(I didn't use "crypto_xts_" instead because that seems overkill.)

Also constify the tfm context in a couple places, and make
xts_free_instance() use the instance context structure so that it
doesn't just assume the crypto_skcipher_spawn is at the beginning.

Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
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@ebiggers @herbertx
ebiggers authored and herbertx committed Jul 16, 2020
1 parent 10f33d3 commit a874f59
Showing 1 changed file with 72 additions and 65 deletions.
137 changes: 72 additions & 65 deletions crypto/xts.c
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Original file line number Diff line number Diff line change
Expand Up @@ -20,7 +20,7 @@
#include <crypto/b128ops.h>
#include <crypto/gf128mul.h>

struct priv {
struct xts_tfm_ctx {
struct crypto_skcipher *child;
struct crypto_cipher *tweak;
};
Expand All @@ -30,17 +30,17 @@ struct xts_instance_ctx {
char name[CRYPTO_MAX_ALG_NAME];
};

struct rctx {
struct xts_request_ctx {
le128 t;
struct scatterlist *tail;
struct scatterlist sg[2];
struct skcipher_request subreq;
};

static int setkey(struct crypto_skcipher *parent, const u8 *key,
unsigned int keylen)
static int xts_setkey(struct crypto_skcipher *parent, const u8 *key,
unsigned int keylen)
{
struct priv *ctx = crypto_skcipher_ctx(parent);
struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(parent);
struct crypto_skcipher *child;
struct crypto_cipher *tweak;
int err;
Expand Down Expand Up @@ -78,9 +78,10 @@ static int setkey(struct crypto_skcipher *parent, const u8 *key,
* mutliple calls to the 'ecb(..)' instance, which usually would be slower than
* just doing the gf128mul_x_ble() calls again.
*/
static int xor_tweak(struct skcipher_request *req, bool second_pass, bool enc)
static int xts_xor_tweak(struct skcipher_request *req, bool second_pass,
bool enc)
{
struct rctx *rctx = skcipher_request_ctx(req);
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
const bool cts = (req->cryptlen % XTS_BLOCK_SIZE);
const int bs = XTS_BLOCK_SIZE;
Expand Down Expand Up @@ -128,23 +129,23 @@ static int xor_tweak(struct skcipher_request *req, bool second_pass, bool enc)
return err;
}

static int xor_tweak_pre(struct skcipher_request *req, bool enc)
static int xts_xor_tweak_pre(struct skcipher_request *req, bool enc)
{
return xor_tweak(req, false, enc);
return xts_xor_tweak(req, false, enc);
}

static int xor_tweak_post(struct skcipher_request *req, bool enc)
static int xts_xor_tweak_post(struct skcipher_request *req, bool enc)
{
return xor_tweak(req, true, enc);
return xts_xor_tweak(req, true, enc);
}

static void cts_done(struct crypto_async_request *areq, int err)
static void xts_cts_done(struct crypto_async_request *areq, int err)
{
struct skcipher_request *req = areq->data;
le128 b;

if (!err) {
struct rctx *rctx = skcipher_request_ctx(req);
struct xts_request_ctx *rctx = skcipher_request_ctx(req);

scatterwalk_map_and_copy(&b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
le128_xor(&b, &rctx->t, &b);
Expand All @@ -154,12 +155,13 @@ static void cts_done(struct crypto_async_request *areq, int err)
skcipher_request_complete(req, err);
}

static int cts_final(struct skcipher_request *req,
int (*crypt)(struct skcipher_request *req))
static int xts_cts_final(struct skcipher_request *req,
int (*crypt)(struct skcipher_request *req))
{
struct priv *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
const struct xts_tfm_ctx *ctx =
crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
int offset = req->cryptlen & ~(XTS_BLOCK_SIZE - 1);
struct rctx *rctx = skcipher_request_ctx(req);
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
struct skcipher_request *subreq = &rctx->subreq;
int tail = req->cryptlen % XTS_BLOCK_SIZE;
le128 b[2];
Expand All @@ -177,7 +179,8 @@ static int cts_final(struct skcipher_request *req,
scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE + tail, 1);

skcipher_request_set_tfm(subreq, ctx->child);
skcipher_request_set_callback(subreq, req->base.flags, cts_done, req);
skcipher_request_set_callback(subreq, req->base.flags, xts_cts_done,
req);
skcipher_request_set_crypt(subreq, rctx->tail, rctx->tail,
XTS_BLOCK_SIZE, NULL);

Expand All @@ -192,18 +195,18 @@ static int cts_final(struct skcipher_request *req,
return 0;
}

static void encrypt_done(struct crypto_async_request *areq, int err)
static void xts_encrypt_done(struct crypto_async_request *areq, int err)
{
struct skcipher_request *req = areq->data;

if (!err) {
struct rctx *rctx = skcipher_request_ctx(req);
struct xts_request_ctx *rctx = skcipher_request_ctx(req);

rctx->subreq.base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
err = xor_tweak_post(req, true);
err = xts_xor_tweak_post(req, true);

if (!err && unlikely(req->cryptlen % XTS_BLOCK_SIZE)) {
err = cts_final(req, crypto_skcipher_encrypt);
err = xts_cts_final(req, crypto_skcipher_encrypt);
if (err == -EINPROGRESS)
return;
}
Expand All @@ -212,18 +215,18 @@ static void encrypt_done(struct crypto_async_request *areq, int err)
skcipher_request_complete(req, err);
}

static void decrypt_done(struct crypto_async_request *areq, int err)
static void xts_decrypt_done(struct crypto_async_request *areq, int err)
{
struct skcipher_request *req = areq->data;

if (!err) {
struct rctx *rctx = skcipher_request_ctx(req);
struct xts_request_ctx *rctx = skcipher_request_ctx(req);

rctx->subreq.base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
err = xor_tweak_post(req, false);
err = xts_xor_tweak_post(req, false);

if (!err && unlikely(req->cryptlen % XTS_BLOCK_SIZE)) {
err = cts_final(req, crypto_skcipher_decrypt);
err = xts_cts_final(req, crypto_skcipher_decrypt);
if (err == -EINPROGRESS)
return;
}
Expand All @@ -232,10 +235,12 @@ static void decrypt_done(struct crypto_async_request *areq, int err)
skcipher_request_complete(req, err);
}

static int init_crypt(struct skcipher_request *req, crypto_completion_t compl)
static int xts_init_crypt(struct skcipher_request *req,
crypto_completion_t compl)
{
struct priv *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
struct rctx *rctx = skcipher_request_ctx(req);
const struct xts_tfm_ctx *ctx =
crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
struct skcipher_request *subreq = &rctx->subreq;

if (req->cryptlen < XTS_BLOCK_SIZE)
Expand All @@ -252,45 +257,45 @@ static int init_crypt(struct skcipher_request *req, crypto_completion_t compl)
return 0;
}

static int encrypt(struct skcipher_request *req)
static int xts_encrypt(struct skcipher_request *req)
{
struct rctx *rctx = skcipher_request_ctx(req);
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
struct skcipher_request *subreq = &rctx->subreq;
int err;

err = init_crypt(req, encrypt_done) ?:
xor_tweak_pre(req, true) ?:
err = xts_init_crypt(req, xts_encrypt_done) ?:
xts_xor_tweak_pre(req, true) ?:
crypto_skcipher_encrypt(subreq) ?:
xor_tweak_post(req, true);
xts_xor_tweak_post(req, true);

if (err || likely((req->cryptlen % XTS_BLOCK_SIZE) == 0))
return err;

return cts_final(req, crypto_skcipher_encrypt);
return xts_cts_final(req, crypto_skcipher_encrypt);
}

static int decrypt(struct skcipher_request *req)
static int xts_decrypt(struct skcipher_request *req)
{
struct rctx *rctx = skcipher_request_ctx(req);
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
struct skcipher_request *subreq = &rctx->subreq;
int err;

err = init_crypt(req, decrypt_done) ?:
xor_tweak_pre(req, false) ?:
err = xts_init_crypt(req, xts_decrypt_done) ?:
xts_xor_tweak_pre(req, false) ?:
crypto_skcipher_decrypt(subreq) ?:
xor_tweak_post(req, false);
xts_xor_tweak_post(req, false);

if (err || likely((req->cryptlen % XTS_BLOCK_SIZE) == 0))
return err;

return cts_final(req, crypto_skcipher_decrypt);
return xts_cts_final(req, crypto_skcipher_decrypt);
}

static int init_tfm(struct crypto_skcipher *tfm)
static int xts_init_tfm(struct crypto_skcipher *tfm)
{
struct skcipher_instance *inst = skcipher_alg_instance(tfm);
struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
struct priv *ctx = crypto_skcipher_ctx(tfm);
struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *child;
struct crypto_cipher *tweak;

Expand All @@ -309,26 +314,28 @@ static int init_tfm(struct crypto_skcipher *tfm)
ctx->tweak = tweak;

crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(child) +
sizeof(struct rctx));
sizeof(struct xts_request_ctx));

return 0;
}

static void exit_tfm(struct crypto_skcipher *tfm)
static void xts_exit_tfm(struct crypto_skcipher *tfm)
{
struct priv *ctx = crypto_skcipher_ctx(tfm);
struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);

crypto_free_skcipher(ctx->child);
crypto_free_cipher(ctx->tweak);
}

static void crypto_xts_free(struct skcipher_instance *inst)
static void xts_free_instance(struct skcipher_instance *inst)
{
crypto_drop_skcipher(skcipher_instance_ctx(inst));
struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);

crypto_drop_skcipher(&ictx->spawn);
kfree(inst);
}

static int create(struct crypto_template *tmpl, struct rtattr **tb)
static int xts_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct skcipher_instance *inst;
struct xts_instance_ctx *ctx;
Expand Down Expand Up @@ -416,43 +423,43 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) * 2;
inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) * 2;

inst->alg.base.cra_ctxsize = sizeof(struct priv);
inst->alg.base.cra_ctxsize = sizeof(struct xts_tfm_ctx);

inst->alg.init = init_tfm;
inst->alg.exit = exit_tfm;
inst->alg.init = xts_init_tfm;
inst->alg.exit = xts_exit_tfm;

inst->alg.setkey = setkey;
inst->alg.encrypt = encrypt;
inst->alg.decrypt = decrypt;
inst->alg.setkey = xts_setkey;
inst->alg.encrypt = xts_encrypt;
inst->alg.decrypt = xts_decrypt;

inst->free = crypto_xts_free;
inst->free = xts_free_instance;

err = skcipher_register_instance(tmpl, inst);
if (err) {
err_free_inst:
crypto_xts_free(inst);
xts_free_instance(inst);
}
return err;
}

static struct crypto_template crypto_tmpl = {
static struct crypto_template xts_tmpl = {
.name = "xts",
.create = create,
.create = xts_create,
.module = THIS_MODULE,
};

static int __init crypto_module_init(void)
static int __init xts_module_init(void)
{
return crypto_register_template(&crypto_tmpl);
return crypto_register_template(&xts_tmpl);
}

static void __exit crypto_module_exit(void)
static void __exit xts_module_exit(void)
{
crypto_unregister_template(&crypto_tmpl);
crypto_unregister_template(&xts_tmpl);
}

subsys_initcall(crypto_module_init);
module_exit(crypto_module_exit);
subsys_initcall(xts_module_init);
module_exit(xts_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("XTS block cipher mode");
Expand Down

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