This patch adds code to the skcipher/lskcipher API to make use
of the internal state if present. In particular, the skcipher
lskcipher wrapper will allocate a buffer for the IV/state and
feed that to the underlying lskcipher algorithm.
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
---
crypto/lskcipher.c | 34 ++++++++++++++++++++----
crypto/skcipher.c | 64 ++++++++++++++++++++++++++++++++++++++++++++--
include/crypto/skcipher.h | 33 +++++++++++++++++++++++
3 files changed, 123 insertions(+), 8 deletions(-)
diff --git a/crypto/lskcipher.c b/crypto/lskcipher.c
index 51bcf85070c7..e6b87787bd64 100644
--- a/crypto/lskcipher.c
+++ b/crypto/lskcipher.c
@@ -90,6 +90,7 @@ static int crypto_lskcipher_crypt_unaligned(
u8 *iv, int (*crypt)(struct crypto_lskcipher *tfm, const u8 *src,
u8 *dst, unsigned len, u8 *iv, u32 flags))
{
+ unsigned statesize = crypto_lskcipher_statesize(tfm);
unsigned ivsize = crypto_lskcipher_ivsize(tfm);
unsigned bs = crypto_lskcipher_blocksize(tfm);
unsigned cs = crypto_lskcipher_chunksize(tfm);
@@ -104,7 +105,7 @@ static int crypto_lskcipher_crypt_unaligned(
if (!tiv)
return -ENOMEM;
- memcpy(tiv, iv, ivsize);
+ memcpy(tiv, iv, ivsize + statesize);
p = kmalloc(PAGE_SIZE, GFP_ATOMIC);
err = -ENOMEM;
@@ -132,7 +133,7 @@ static int crypto_lskcipher_crypt_unaligned(
err = len ? -EINVAL : 0;
out:
- memcpy(iv, tiv, ivsize);
+ memcpy(iv, tiv, ivsize + statesize);
kfree_sensitive(p);
kfree_sensitive(tiv);
return err;
@@ -197,25 +198,45 @@ EXPORT_SYMBOL_GPL(crypto_lskcipher_decrypt);
static int crypto_lskcipher_crypt_sg(struct skcipher_request *req,
int (*crypt)(struct crypto_lskcipher *tfm,
const u8 *src, u8 *dst,
- unsigned len, u8 *iv,
+ unsigned len, u8 *ivs,
u32 flags))
{
struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);
+ u8 *ivs = skcipher_request_ctx(req);
struct crypto_lskcipher *tfm = *ctx;
struct skcipher_walk walk;
+ unsigned ivsize;
+ u32 flags;
int err;
+ ivsize = crypto_lskcipher_ivsize(tfm);
+ ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(skcipher) + 1);
+
+ flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ if (req->base.flags & CRYPTO_SKCIPHER_REQ_CONT)
+ flags |= CRYPTO_LSKCIPHER_FLAG_CONT;
+ else
+ memcpy(ivs, req->iv, ivsize);
+
+ if (!(req->base.flags & CRYPTO_SKCIPHER_REQ_NOTFINAL))
+ flags |= CRYPTO_LSKCIPHER_FLAG_FINAL;
+
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes) {
err = crypt(tfm, walk.src.virt.addr, walk.dst.virt.addr,
- walk.nbytes, walk.iv,
- walk.nbytes == walk.total ?
- CRYPTO_LSKCIPHER_FLAG_FINAL : 0);
+ walk.nbytes, ivs,
+ flags & ~(walk.nbytes == walk.total ?
+ 0 : CRYPTO_LSKCIPHER_FLAG_FINAL));
err = skcipher_walk_done(&walk, err);
+ flags |= CRYPTO_LSKCIPHER_FLAG_CONT;
}
+ if (flags & CRYPTO_LSKCIPHER_FLAG_FINAL)
+ memcpy(req->iv, ivs, ivsize);
+
return err;
}
@@ -278,6 +299,7 @@ static void __maybe_unused crypto_lskcipher_show(
seq_printf(m, "max keysize : %u\n", skcipher->co.max_keysize);
seq_printf(m, "ivsize : %u\n", skcipher->co.ivsize);
seq_printf(m, "chunksize : %u\n", skcipher->co.chunksize);
+ seq_printf(m, "statesize : %u\n", skcipher->co.statesize);
}
static int __maybe_unused crypto_lskcipher_report(
diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index ac8b8c042654..b8e1d15c2807 100644
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -698,6 +698,54 @@ int crypto_skcipher_decrypt(struct skcipher_request *req)
}
EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt);
+static int crypto_lskcipher_export(struct skcipher_request *req, void *out)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ u8 *ivs = skcipher_request_ctx(req);
+
+ ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(tfm) + 1);
+
+ memcpy(out, ivs + crypto_skcipher_ivsize(tfm),
+ crypto_skcipher_statesize(tfm));
+
+ return 0;
+}
+
+static int crypto_lskcipher_import(struct skcipher_request *req, const void *in)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ u8 *ivs = skcipher_request_ctx(req);
+
+ ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(tfm) + 1);
+
+ memcpy(ivs + crypto_skcipher_ivsize(tfm), in,
+ crypto_skcipher_statesize(tfm));
+
+ return 0;
+}
+
+int crypto_skcipher_export(struct skcipher_request *req, void *out)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
+
+ if (alg->co.base.cra_type != &crypto_skcipher_type)
+ return crypto_lskcipher_export(req, out);
+ return alg->export(req, out);
+}
+EXPORT_SYMBOL_GPL(crypto_skcipher_export);
+
+int crypto_skcipher_import(struct skcipher_request *req, const void *in)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
+
+ if (alg->co.base.cra_type != &crypto_skcipher_type)
+ return crypto_lskcipher_import(req, in);
+ return alg->import(req, in);
+}
+EXPORT_SYMBOL_GPL(crypto_skcipher_import);
+
static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
@@ -713,8 +761,17 @@ static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
skcipher_set_needkey(skcipher);
- if (tfm->__crt_alg->cra_type != &crypto_skcipher_type)
+ if (tfm->__crt_alg->cra_type != &crypto_skcipher_type) {
+ unsigned am = crypto_skcipher_alignmask(skcipher);
+ unsigned reqsize;
+
+ reqsize = am & ~(crypto_tfm_ctx_alignment() - 1);
+ reqsize += crypto_skcipher_ivsize(skcipher);
+ reqsize += crypto_skcipher_statesize(skcipher);
+ crypto_skcipher_set_reqsize(skcipher, reqsize);
+
return crypto_init_lskcipher_ops_sg(tfm);
+ }
if (alg->exit)
skcipher->base.exit = crypto_skcipher_exit_tfm;
@@ -756,6 +813,7 @@ static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
seq_printf(m, "ivsize : %u\n", skcipher->ivsize);
seq_printf(m, "chunksize : %u\n", skcipher->chunksize);
seq_printf(m, "walksize : %u\n", skcipher->walksize);
+ seq_printf(m, "statesize : %u\n", skcipher->statesize);
}
static int __maybe_unused crypto_skcipher_report(
@@ -870,7 +928,9 @@ int skcipher_prepare_alg_common(struct skcipher_alg_common *alg)
struct crypto_istat_cipher *istat = skcipher_get_stat_common(alg);
struct crypto_alg *base = &alg->base;
- if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8)
+ if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
+ alg->statesize > PAGE_SIZE / 2 ||
+ (alg->ivsize + alg->statesize) > PAGE_SIZE / 2)
return -EINVAL;
if (!alg->chunksize)
diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h
index 0cfbe86f957b..b2faab27bed4 100644
--- a/include/crypto/skcipher.h
+++ b/include/crypto/skcipher.h
@@ -746,6 +746,39 @@ int crypto_skcipher_encrypt(struct skcipher_request *req);
*/
int crypto_skcipher_decrypt(struct skcipher_request *req);
+/**
+ * crypto_skcipher_export() - export partial state
+ * @req: reference to the skcipher_request handle that holds all information
+ * needed to perform the operation
+ * @out: output buffer of sufficient size that can hold the state
+ *
+ * Export partial state of the transformation. This function dumps the
+ * entire state of the ongoing transformation into a provided block of
+ * data so it can be @import 'ed back later on. This is useful in case
+ * you want to save partial result of the transformation after
+ * processing certain amount of data and reload this partial result
+ * multiple times later on for multiple re-use. No data processing
+ * happens at this point.
+ *
+ * Return: 0 if the cipher operation was successful; < 0 if an error occurred
+ */
+int crypto_skcipher_export(struct skcipher_request *req, void *out);
+
+/**
+ * crypto_skcipher_import() - import partial state
+ * @req: reference to the skcipher_request handle that holds all information
+ * needed to perform the operation
+ * @in: buffer holding the state
+ *
+ * Import partial state of the transformation. This function loads the
+ * entire state of the ongoing transformation from a provided block of
+ * data so the transformation can continue from this point onward. No
+ * data processing happens at this point.
+ *
+ * Return: 0 if the cipher operation was successful; < 0 if an error occurred
+ */
+int crypto_skcipher_import(struct skcipher_request *req, const void *in);
+
/**
* crypto_lskcipher_encrypt() - encrypt plaintext
* @tfm: lskcipher handle
