crypto: skcipher - Add lskcipher

Add a new API type lskcipher designed for taking straight kernel
pointers instead of SG lists.  Its relationship to skcipher will
be analogous to that between shash and ahash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 397 insertions, 26 deletions

diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h
index fb3d9e899f52..4382fd707b8a 100644
--- a/include/crypto/internal/skcipher.h
+++ b/include/crypto/internal/skcipher.h
@@ -36,10 +36,25 @@ struct skcipher_instance {
 	};
 };
 
+struct lskcipher_instance {
+	void (*free)(struct lskcipher_instance *inst);
+	union {
+		struct {
+			char head[offsetof(struct lskcipher_alg, co.base)];
+			struct crypto_instance base;
+		} s;
+		struct lskcipher_alg alg;
+	};
+};
+
 struct crypto_skcipher_spawn {
 	struct crypto_spawn base;
 };
 
+struct crypto_lskcipher_spawn {
+	struct crypto_spawn base;
+};
+
 struct skcipher_walk {
 	union {
 		struct {
@@ -80,6 +95,12 @@ static inline struct crypto_instance *skcipher_crypto_instance(
 	return &inst->s.base;
 }
 
+static inline struct crypto_instance *lskcipher_crypto_instance(
+	struct lskcipher_instance *inst)
+{
+	return &inst->s.base;
+}
+
 static inline struct skcipher_instance *skcipher_alg_instance(
 	struct crypto_skcipher *skcipher)
 {
@@ -87,11 +108,23 @@ static inline struct skcipher_instance *skcipher_alg_instance(
 			    struct skcipher_instance, alg);
 }
 
+static inline struct lskcipher_instance *lskcipher_alg_instance(
+	struct crypto_lskcipher *lskcipher)
+{
+	return container_of(crypto_lskcipher_alg(lskcipher),
+			    struct lskcipher_instance, alg);
+}
+
 static inline void *skcipher_instance_ctx(struct skcipher_instance *inst)
 {
 	return crypto_instance_ctx(skcipher_crypto_instance(inst));
 }
 
+static inline void *lskcipher_instance_ctx(struct lskcipher_instance *inst)
+{
+	return crypto_instance_ctx(lskcipher_crypto_instance(inst));
+}
+
 static inline void skcipher_request_complete(struct skcipher_request *req, int err)
 {
 	crypto_request_complete(&req->base, err);
@@ -101,29 +134,56 @@ int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
 			 struct crypto_instance *inst,
 			 const char *name, u32 type, u32 mask);
 
+int crypto_grab_lskcipher(struct crypto_lskcipher_spawn *spawn,
+			  struct crypto_instance *inst,
+			  const char *name, u32 type, u32 mask);
+
 static inline void crypto_drop_skcipher(struct crypto_skcipher_spawn *spawn)
 {
 	crypto_drop_spawn(&spawn->base);
 }
 
+static inline void crypto_drop_lskcipher(struct crypto_lskcipher_spawn *spawn)
+{
+	crypto_drop_spawn(&spawn->base);
+}
+
 static inline struct skcipher_alg *crypto_skcipher_spawn_alg(
 	struct crypto_skcipher_spawn *spawn)
 {
 	return container_of(spawn->base.alg, struct skcipher_alg, base);
 }
 
+static inline struct lskcipher_alg *crypto_lskcipher_spawn_alg(
+	struct crypto_lskcipher_spawn *spawn)
+{
+	return container_of(spawn->base.alg, struct lskcipher_alg, co.base);
+}
+
 static inline struct skcipher_alg *crypto_spawn_skcipher_alg(
 	struct crypto_skcipher_spawn *spawn)
 {
 	return crypto_skcipher_spawn_alg(spawn);
 }
 
+static inline struct lskcipher_alg *crypto_spawn_lskcipher_alg(
+	struct crypto_lskcipher_spawn *spawn)
+{
+	return crypto_lskcipher_spawn_alg(spawn);
+}
+
 static inline struct crypto_skcipher *crypto_spawn_skcipher(
 	struct crypto_skcipher_spawn *spawn)
 {
 	return crypto_spawn_tfm2(&spawn->base);
 }
 
+static inline struct crypto_lskcipher *crypto_spawn_lskcipher(
+	struct crypto_lskcipher_spawn *spawn)
+{
+	return crypto_spawn_tfm2(&spawn->base);
+}
+
 static inline void crypto_skcipher_set_reqsize(
 	struct crypto_skcipher *skcipher, unsigned int reqsize)
 {
@@ -144,6 +204,13 @@ void crypto_unregister_skciphers(struct skcipher_alg *algs, int count);
 int skcipher_register_instance(struct crypto_template *tmpl,
 			       struct skcipher_instance *inst);
 
+int crypto_register_lskcipher(struct lskcipher_alg *alg);
+void crypto_unregister_lskcipher(struct lskcipher_alg *alg);
+int crypto_register_lskciphers(struct lskcipher_alg *algs, int count);
+void crypto_unregister_lskciphers(struct lskcipher_alg *algs, int count);
+int lskcipher_register_instance(struct crypto_template *tmpl,
+				struct lskcipher_instance *inst);
+
 int skcipher_walk_done(struct skcipher_walk *walk, int err);
 int skcipher_walk_virt(struct skcipher_walk *walk,
 		       struct skcipher_request *req,
@@ -166,6 +233,11 @@ static inline void *crypto_skcipher_ctx(struct crypto_skcipher *tfm)
 	return crypto_tfm_ctx(&tfm->base);
 }
 
+static inline void *crypto_lskcipher_ctx(struct crypto_lskcipher *tfm)
+{
+	return crypto_tfm_ctx(&tfm->base);
+}
+
 static inline void *crypto_skcipher_ctx_dma(struct crypto_skcipher *tfm)
 {
 	return crypto_tfm_ctx_dma(&tfm->base);
@@ -209,21 +281,16 @@ static inline unsigned int crypto_skcipher_alg_walksize(
 	return alg->walksize;
 }
 
-/**
- * crypto_skcipher_walksize() - obtain walk size
- * @tfm: cipher handle
- *
- * In some cases, algorithms can only perform optimally when operating on
- * multiple blocks in parallel. This is reflected by the walksize, which
- * must be a multiple of the chunksize (or equal if the concern does not
- * apply)
- *
- * Return: walk size in bytes
- */
-static inline unsigned int crypto_skcipher_walksize(
-	struct crypto_skcipher *tfm)
+static inline unsigned int crypto_lskcipher_alg_min_keysize(
+	struct lskcipher_alg *alg)
+{
+	return alg->co.min_keysize;
+}
+
+static inline unsigned int crypto_lskcipher_alg_max_keysize(
+	struct lskcipher_alg *alg)
 {
-	return crypto_skcipher_alg_walksize(crypto_skcipher_alg(tfm));
+	return alg->co.max_keysize;
 }
 
 /* Helpers for simple block cipher modes of operation */
@@ -249,5 +316,24 @@ static inline struct crypto_alg *skcipher_ialg_simple(
 	return crypto_spawn_cipher_alg(spawn);
 }
 
+static inline struct crypto_lskcipher *lskcipher_cipher_simple(
+	struct crypto_lskcipher *tfm)
+{
+	struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);
+
+	return *ctx;
+}
+
+struct lskcipher_instance *lskcipher_alloc_instance_simple(
+	struct crypto_template *tmpl, struct rtattr **tb);
+
+static inline struct lskcipher_alg *lskcipher_ialg_simple(
+	struct lskcipher_instance *inst)
+{
+	struct crypto_lskcipher_spawn *spawn = lskcipher_instance_ctx(inst);
+
+	return crypto_lskcipher_spawn_alg(spawn);
+}
+
 #endif	/* _CRYPTO_INTERNAL_SKCIPHER_H */
 
diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h
index 080d1ba3611d..a648ef5ce897 100644
--- a/include/crypto/skcipher.h
+++ b/include/crypto/skcipher.h
@@ -49,6 +49,10 @@ struct crypto_sync_skcipher {
 	struct crypto_skcipher base;
 };
 
+struct crypto_lskcipher {
+	struct crypto_tfm base;
+};
+
 /*
  * struct crypto_istat_cipher - statistics for cipher algorithm
  * @encrypt_cnt:	number of encrypt requests
@@ -65,6 +69,43 @@ struct crypto_istat_cipher {
 	atomic64_t err_cnt;
 };
 
+#ifdef CONFIG_CRYPTO_STATS
+#define SKCIPHER_ALG_COMMON_STAT struct crypto_istat_cipher stat;
+#else
+#define SKCIPHER_ALG_COMMON_STAT
+#endif
+
+/*
+ * struct skcipher_alg_common - common properties of skcipher_alg
+ * @min_keysize: Minimum key size supported by the transformation. This is the
+ *		 smallest key length supported by this transformation algorithm.
+ *		 This must be set to one of the pre-defined values as this is
+ *		 not hardware specific. Possible values for this field can be
+ *		 found via git grep "_MIN_KEY_SIZE" include/crypto/
+ * @max_keysize: Maximum key size supported by the transformation. This is the
+ *		 largest key length supported by this transformation algorithm.
+ *		 This must be set to one of the pre-defined values as this is
+ *		 not hardware specific. Possible values for this field can be
+ *		 found via git grep "_MAX_KEY_SIZE" include/crypto/
+ * @ivsize: IV size applicable for transformation. The consumer must provide an
+ *	    IV of exactly that size to perform the encrypt or decrypt operation.
+ * @chunksize: Equal to the block size except for stream ciphers such as
+ *	       CTR where it is set to the underlying block size.
+ * @stat: Statistics for cipher algorithm
+ * @base: Definition of a generic crypto algorithm.
+ */
+#define SKCIPHER_ALG_COMMON {		\
+	unsigned int min_keysize;	\
+	unsigned int max_keysize;	\
+	unsigned int ivsize;		\
+	unsigned int chunksize;		\
+					\
+	SKCIPHER_ALG_COMMON_STAT	\
+					\
+	struct crypto_alg base;		\
+}
+struct skcipher_alg_common SKCIPHER_ALG_COMMON;
+
 /**
  * struct skcipher_alg - symmetric key cipher definition
  * @min_keysize: Minimum key size supported by the transformation. This is the
@@ -120,6 +161,7 @@ struct crypto_istat_cipher {
  * 	      in parallel. Should be a multiple of chunksize.
  * @stat: Statistics for cipher algorithm
  * @base: Definition of a generic crypto algorithm.
+ * @co: see struct skcipher_alg_common
  *
  * All fields except @ivsize are mandatory and must be filled.
  */
@@ -131,17 +173,55 @@ struct skcipher_alg {
 	int (*init)(struct crypto_skcipher *tfm);
 	void (*exit)(struct crypto_skcipher *tfm);
 
-	unsigned int min_keysize;
-	unsigned int max_keysize;
-	unsigned int ivsize;
-	unsigned int chunksize;
 	unsigned int walksize;
 
-#ifdef CONFIG_CRYPTO_STATS
-	struct crypto_istat_cipher stat;
-#endif
+	union {
+		struct SKCIPHER_ALG_COMMON;
+		struct skcipher_alg_common co;
+	};
+};
 
-	struct crypto_alg base;
+/**
+ * struct lskcipher_alg - linear symmetric key cipher definition
+ * @setkey: Set key for the transformation. This function is used to either
+ *	    program a supplied key into the hardware or store the key in the
+ *	    transformation context for programming it later. Note that this
+ *	    function does modify the transformation context. This function can
+ *	    be called multiple times during the existence of the transformation
+ *	    object, so one must make sure the key is properly reprogrammed into
+ *	    the hardware. This function is also responsible for checking the key
+ *	    length for validity. In case a software fallback was put in place in
+ *	    the @cra_init call, this function might need to use the fallback if
+ *	    the algorithm doesn't support all of the key sizes.
+ * @encrypt: Encrypt a number of bytes. This function is used to encrypt
+ *	     the supplied data.  This function shall not modify
+ *	     the transformation context, as this function may be called
+ *	     in parallel with the same transformation object.  Data
+ *	     may be left over if length is not a multiple of blocks
+ *	     and there is more to come (final == false).  The number of
+ *	     left-over bytes should be returned in case of success.
+ * @decrypt: Decrypt a number of bytes. This is a reverse counterpart to
+ *	     @encrypt and the conditions are exactly the same.
+ * @init: Initialize the cryptographic transformation object. This function
+ *	  is used to initialize the cryptographic transformation object.
+ *	  This function is called only once at the instantiation time, right
+ *	  after the transformation context was allocated.
+ * @exit: Deinitialize the cryptographic transformation object. This is a
+ *	  counterpart to @init, used to remove various changes set in
+ *	  @init.
+ * @co: see struct skcipher_alg_common
+ */
+struct lskcipher_alg {
+	int (*setkey)(struct crypto_lskcipher *tfm, const u8 *key,
+	              unsigned int keylen);
+	int (*encrypt)(struct crypto_lskcipher *tfm, const u8 *src,
+		       u8 *dst, unsigned len, u8 *iv, bool final);
+	int (*decrypt)(struct crypto_lskcipher *tfm, const u8 *src,
+		       u8 *dst, unsigned len, u8 *iv, bool final);
+	int (*init)(struct crypto_lskcipher *tfm);
+	void (*exit)(struct crypto_lskcipher *tfm);
+
+	struct skcipher_alg_common co;
 };
 
 #define MAX_SYNC_SKCIPHER_REQSIZE      384
@@ -213,12 +293,36 @@ struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(const char *alg_name,
 					      u32 type, u32 mask);
 
+
+/**
+ * crypto_alloc_lskcipher() - allocate linear symmetric key cipher handle
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ *	      lskcipher
+ * @type: specifies the type of the cipher
+ * @mask: specifies the mask for the cipher
+ *
+ * Allocate a cipher handle for an lskcipher. The returned struct
+ * crypto_lskcipher is the cipher handle that is required for any subsequent
+ * API invocation for that lskcipher.
+ *
+ * Return: allocated cipher handle in case of success; IS_ERR() is true in case
+ *	   of an error, PTR_ERR() returns the error code.
+ */
+struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name,
+						u32 type, u32 mask);
+
 static inline struct crypto_tfm *crypto_skcipher_tfm(
 	struct crypto_skcipher *tfm)
 {
 	return &tfm->base;
 }
 
+static inline struct crypto_tfm *crypto_lskcipher_tfm(
+	struct crypto_lskcipher *tfm)
+{
+	return &tfm->base;
+}
+
 /**
  * crypto_free_skcipher() - zeroize and free cipher handle
  * @tfm: cipher handle to be freed
@@ -236,6 +340,17 @@ static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
 }
 
 /**
+ * crypto_free_lskcipher() - zeroize and free cipher handle
+ * @tfm: cipher handle to be freed
+ *
+ * If @tfm is a NULL or error pointer, this function does nothing.
+ */
+static inline void crypto_free_lskcipher(struct crypto_lskcipher *tfm)
+{
+	crypto_destroy_tfm(tfm, crypto_lskcipher_tfm(tfm));
+}
+
+/**
  * crypto_has_skcipher() - Search for the availability of an skcipher.
  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
  *	      skcipher
@@ -253,6 +368,19 @@ static inline const char *crypto_skcipher_driver_name(
 	return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
 }
 
+static inline const char *crypto_lskcipher_driver_name(
+	struct crypto_lskcipher *tfm)
+{
+	return crypto_tfm_alg_driver_name(crypto_lskcipher_tfm(tfm));
+}
+
+static inline struct skcipher_alg_common *crypto_skcipher_alg_common(
+	struct crypto_skcipher *tfm)
+{
+	return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
+			    struct skcipher_alg_common, base);
+}
+
 static inline struct skcipher_alg *crypto_skcipher_alg(
 	struct crypto_skcipher *tfm)
 {
@@ -260,11 +388,24 @@ static inline struct skcipher_alg *crypto_skcipher_alg(
 			    struct skcipher_alg, base);
 }
 
+static inline struct lskcipher_alg *crypto_lskcipher_alg(
+	struct crypto_lskcipher *tfm)
+{
+	return container_of(crypto_lskcipher_tfm(tfm)->__crt_alg,
+			    struct lskcipher_alg, co.base);
+}
+
 static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
 {
 	return alg->ivsize;
 }
 
+static inline unsigned int crypto_lskcipher_alg_ivsize(
+	struct lskcipher_alg *alg)
+{
+	return alg->co.ivsize;
+}
+
 /**
  * crypto_skcipher_ivsize() - obtain IV size
  * @tfm: cipher handle
@@ -276,7 +417,7 @@ static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
  */
 static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
 {
-	return crypto_skcipher_alg(tfm)->ivsize;
+	return crypto_skcipher_alg_common(tfm)->ivsize;
 }
 
 static inline unsigned int crypto_sync_skcipher_ivsize(
@@ -286,6 +427,21 @@ static inline unsigned int crypto_sync_skcipher_ivsize(
 }
 
 /**
+ * crypto_lskcipher_ivsize() - obtain IV size
+ * @tfm: cipher handle
+ *
+ * The size of the IV for the lskcipher referenced by the cipher handle is
+ * returned. This IV size may be zero if the cipher does not need an IV.
+ *
+ * Return: IV size in bytes
+ */
+static inline unsigned int crypto_lskcipher_ivsize(
+	struct crypto_lskcipher *tfm)
+{
+	return crypto_lskcipher_alg(tfm)->co.ivsize;
+}
+
+/**
  * crypto_skcipher_blocksize() - obtain block size of cipher
  * @tfm: cipher handle
  *
@@ -301,12 +457,34 @@ static inline unsigned int crypto_skcipher_blocksize(
 	return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
 }
 
+/**
+ * crypto_lskcipher_blocksize() - obtain block size of cipher
+ * @tfm: cipher handle
+ *
+ * The block size for the lskcipher referenced with the cipher handle is
+ * returned. The caller may use that information to allocate appropriate
+ * memory for the data returned by the encryption or decryption operation
+ *
+ * Return: block size of cipher
+ */
+static inline unsigned int crypto_lskcipher_blocksize(
+	struct crypto_lskcipher *tfm)
+{
+	return crypto_tfm_alg_blocksize(crypto_lskcipher_tfm(tfm));
+}
+
 static inline unsigned int crypto_skcipher_alg_chunksize(
 	struct skcipher_alg *alg)
 {
 	return alg->chunksize;
 }
 
+static inline unsigned int crypto_lskcipher_alg_chunksize(
+	struct lskcipher_alg *alg)
+{
+	return alg->co.chunksize;
+}
+
 /**
  * crypto_skcipher_chunksize() - obtain chunk size
  * @tfm: cipher handle
@@ -321,7 +499,24 @@ static inline unsigned int crypto_skcipher_alg_chunksize(
 static inline unsigned int crypto_skcipher_chunksize(
 	struct crypto_skcipher *tfm)
 {
-	return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm));
+	return crypto_skcipher_alg_common(tfm)->chunksize;
+}
+
+/**
+ * crypto_lskcipher_chunksize() - obtain chunk size
+ * @tfm: cipher handle
+ *
+ * The block size is set to one for ciphers such as CTR.  However,
+ * you still need to provide incremental updates in multiples of
+ * the underlying block size as the IV does not have sub-block
+ * granularity.  This is known in this API as the chunk size.
+ *
+ * Return: chunk size in bytes
+ */
+static inline unsigned int crypto_lskcipher_chunksize(
+	struct crypto_lskcipher *tfm)
+{
+	return crypto_lskcipher_alg_chunksize(crypto_lskcipher_alg(tfm));
 }
 
 static inline unsigned int crypto_sync_skcipher_blocksize(
@@ -336,6 +531,12 @@ static inline unsigned int crypto_skcipher_alignmask(
 	return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
 }
 
+static inline unsigned int crypto_lskcipher_alignmask(
+	struct crypto_lskcipher *tfm)
+{
+	return crypto_tfm_alg_alignmask(crypto_lskcipher_tfm(tfm));
+}
+
 static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
 {
 	return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
@@ -371,6 +572,23 @@ static inline void crypto_sync_skcipher_clear_flags(
 	crypto_skcipher_clear_flags(&tfm->base, flags);
 }
 
+static inline u32 crypto_lskcipher_get_flags(struct crypto_lskcipher *tfm)
+{
+	return crypto_tfm_get_flags(crypto_lskcipher_tfm(tfm));
+}
+
+static inline void crypto_lskcipher_set_flags(struct crypto_lskcipher *tfm,
+					       u32 flags)
+{
+	crypto_tfm_set_flags(crypto_lskcipher_tfm(tfm), flags);
+}
+
+static inline void crypto_lskcipher_clear_flags(struct crypto_lskcipher *tfm,
+						 u32 flags)
+{
+	crypto_tfm_clear_flags(crypto_lskcipher_tfm(tfm), flags);
+}
+
 /**
  * crypto_skcipher_setkey() - set key for cipher
  * @tfm: cipher handle
@@ -396,16 +614,47 @@ static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
 	return crypto_skcipher_setkey(&tfm->base, key, keylen);
 }
 
+/**
+ * crypto_lskcipher_setkey() - set key for cipher
+ * @tfm: cipher handle
+ * @key: buffer holding the key
+ * @keylen: length of the key in bytes
+ *
+ * The caller provided key is set for the lskcipher referenced by the cipher
+ * handle.
+ *
+ * Note, the key length determines the cipher type. Many block ciphers implement
+ * different cipher modes depending on the key size, such as AES-128 vs AES-192
+ * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
+ * is performed.
+ *
+ * Return: 0 if the setting of the key was successful; < 0 if an error occurred
+ */
+int crypto_lskcipher_setkey(struct crypto_lskcipher *tfm,
+			    const u8 *key, unsigned int keylen);
+
 static inline unsigned int crypto_skcipher_min_keysize(
 	struct crypto_skcipher *tfm)
 {
-	return crypto_skcipher_alg(tfm)->min_keysize;
+	return crypto_skcipher_alg_common(tfm)->min_keysize;
 }
 
 static inline unsigned int crypto_skcipher_max_keysize(
 	struct crypto_skcipher *tfm)
 {
-	return crypto_skcipher_alg(tfm)->max_keysize;
+	return crypto_skcipher_alg_common(tfm)->max_keysize;
+}
+
+static inline unsigned int crypto_lskcipher_min_keysize(
+	struct crypto_lskcipher *tfm)
+{
+	return crypto_lskcipher_alg(tfm)->co.min_keysize;
+}
+
+static inline unsigned int crypto_lskcipher_max_keysize(
+	struct crypto_lskcipher *tfm)
+{
+	return crypto_lskcipher_alg(tfm)->co.max_keysize;
 }
 
 /**
@@ -458,6 +707,42 @@ int crypto_skcipher_encrypt(struct skcipher_request *req);
 int crypto_skcipher_decrypt(struct skcipher_request *req);
 
 /**
+ * crypto_lskcipher_encrypt() - encrypt plaintext
+ * @tfm: lskcipher handle
+ * @src: source buffer
+ * @dst: destination buffer
+ * @len: number of bytes to process
+ * @iv: IV for the cipher operation which must comply with the IV size defined
+ *      by crypto_lskcipher_ivsize
+ *
+ * Encrypt plaintext data using the lskcipher handle.
+ *
+ * Return: >=0 if the cipher operation was successful, if positive
+ *	   then this many bytes have been left unprocessed;
+ *	   < 0 if an error occurred
+ */
+int crypto_lskcipher_encrypt(struct crypto_lskcipher *tfm, const u8 *src,
+			     u8 *dst, unsigned len, u8 *iv);
+
+/**
+ * crypto_lskcipher_decrypt() - decrypt ciphertext
+ * @tfm: lskcipher handle
+ * @src: source buffer
+ * @dst: destination buffer
+ * @len: number of bytes to process
+ * @iv: IV for the cipher operation which must comply with the IV size defined
+ *      by crypto_lskcipher_ivsize
+ *
+ * Decrypt ciphertext data using the lskcipher handle.
+ *
+ * Return: >=0 if the cipher operation was successful, if positive
+ *	   then this many bytes have been left unprocessed;
+ *	   < 0 if an error occurred
+ */
+int crypto_lskcipher_decrypt(struct crypto_lskcipher *tfm, const u8 *src,
+			     u8 *dst, unsigned len, u8 *iv);
+
+/**
  * DOC: Symmetric Key Cipher Request Handle
  *
  * The skcipher_request data structure contains all pointers to data