crypto: skcipher - make chunksize and walksize accessors internal

The 'chunksize' and 'walksize' properties of skcipher algorithms are
implementation details that users of the skcipher API should not be
looking at.  So move their accessor functions from <crypto/skcipher.h>
to <crypto/internal/skcipher.h>.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 60 insertions, 0 deletions

diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h
index 9de6032209cb..abb1096495c2 100644
--- a/include/crypto/internal/skcipher.h
+++ b/include/crypto/internal/skcipher.h
@@ -205,6 +205,66 @@ static inline unsigned int crypto_skcipher_alg_max_keysize(
 	return alg->max_keysize;
 }
 
+static inline unsigned int crypto_skcipher_alg_chunksize(
+	struct skcipher_alg *alg)
+{
+	if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_BLKCIPHER)
+		return alg->base.cra_blocksize;
+
+	if (alg->base.cra_ablkcipher.encrypt)
+		return alg->base.cra_blocksize;
+
+	return alg->chunksize;
+}
+
+static inline unsigned int crypto_skcipher_alg_walksize(
+	struct skcipher_alg *alg)
+{
+	if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_BLKCIPHER)
+		return alg->base.cra_blocksize;
+
+	if (alg->base.cra_ablkcipher.encrypt)
+		return alg->base.cra_blocksize;
+
+	return alg->walksize;
+}
+
+/**
+ * crypto_skcipher_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_skcipher_chunksize(
+	struct crypto_skcipher *tfm)
+{
+	return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm));
+}
+
+/**
+ * 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)
+{
+	return crypto_skcipher_alg_walksize(crypto_skcipher_alg(tfm));
+}
+
 /* Helpers for simple block cipher modes of operation */
 struct skcipher_ctx_simple {
 	struct crypto_cipher *cipher;	/* underlying block cipher */