crypto: cipher - remove crt_u.cipher (struct cipher_tfm)

Of the three fields in crt_u.cipher (struct cipher_tfm), ->cit_setkey()
is pointless because it always points to setkey() in crypto/cipher.c.

->cit_decrypt_one() and ->cit_encrypt_one() are slightly less pointless,
since if the algorithm doesn't have an alignmask, they are set directly
to ->cia_encrypt() and ->cia_decrypt().  However, this "optimization"
isn't worthwhile because:

- The "cipher" algorithm type is the only algorithm still using crt_u,
  so it's bloating every struct crypto_tfm for every algorithm type.

- If the algorithm has an alignmask, this "optimization" actually makes
  things slower, as it causes 2 indirect calls per block rather than 1.

- It adds extra code complexity.

- Some templates already call ->cia_encrypt()/->cia_decrypt() directly
  instead of going through ->cit_encrypt_one()/->cit_decrypt_one().

- The "cipher" algorithm type never gives optimal performance anyway.
  For that, a higher-level type such as skcipher needs to be used.

Therefore, just remove the extra indirection, and make
crypto_cipher_setkey(), crypto_cipher_encrypt_one(), and
crypto_cipher_decrypt_one() be direct calls into crypto/cipher.c.

Also remove the unused function crypto_cipher_cast().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 36 insertions, 56 deletions

diff --git a/crypto/cipher.c b/crypto/cipher.c
index 108427026e7c..aadd51cb7250 100644
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -2,7 +2,7 @@
 /*
  * Cryptographic API.
  *
- * Cipher operations.
+ * Single-block cipher operations.
  *
  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
@@ -16,11 +16,11 @@
 #include <linux/string.h>
 #include "internal.h"
 
-static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
+static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
 			    unsigned int keylen)
 {
-	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
-	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+	struct cipher_alg *cia = crypto_cipher_alg(tfm);
+	unsigned long alignmask = crypto_cipher_alignmask(tfm);
 	int ret;
 	u8 *buffer, *alignbuffer;
 	unsigned long absize;
@@ -32,83 +32,63 @@ static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
 
 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 	memcpy(alignbuffer, key, keylen);
-	ret = cia->cia_setkey(tfm, alignbuffer, keylen);
+	ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
 	memset(alignbuffer, 0, keylen);
 	kfree(buffer);
 	return ret;
 
 }
 
-static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
+int crypto_cipher_setkey(struct crypto_cipher *tfm,
+			 const u8 *key, unsigned int keylen)
 {
-	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
-	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+	struct cipher_alg *cia = crypto_cipher_alg(tfm);
+	unsigned long alignmask = crypto_cipher_alignmask(tfm);
 
-	tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
+	crypto_cipher_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
 	if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
-		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+		crypto_cipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 		return -EINVAL;
 	}
 
 	if ((unsigned long)key & alignmask)
 		return setkey_unaligned(tfm, key, keylen);
 
-	return cia->cia_setkey(tfm, key, keylen);
+	return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
 }
+EXPORT_SYMBOL_GPL(crypto_cipher_setkey);
 
-static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
-					      const u8 *),
-				   struct crypto_tfm *tfm,
-				   u8 *dst, const u8 *src)
+static inline void cipher_crypt_one(struct crypto_cipher *tfm,
+				    u8 *dst, const u8 *src, bool enc)
 {
-	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
-	unsigned int size = crypto_tfm_alg_blocksize(tfm);
-	u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
-	u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
-
-	memcpy(tmp, src, size);
-	fn(tfm, tmp, tmp);
-	memcpy(dst, tmp, size);
-}
-
-static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
-				     u8 *dst, const u8 *src)
-{
-	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
-	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
+	unsigned long alignmask = crypto_cipher_alignmask(tfm);
+	struct cipher_alg *cia = crypto_cipher_alg(tfm);
+	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
+		enc ? cia->cia_encrypt : cia->cia_decrypt;
 
 	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
-		cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
-		return;
+		unsigned int bs = crypto_cipher_blocksize(tfm);
+		u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
+		u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+
+		memcpy(tmp, src, bs);
+		fn(crypto_cipher_tfm(tfm), tmp, tmp);
+		memcpy(dst, tmp, bs);
+	} else {
+		fn(crypto_cipher_tfm(tfm), dst, src);
 	}
-
-	cipher->cia_encrypt(tfm, dst, src);
 }
 
-static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
-				     u8 *dst, const u8 *src)
+void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
+			       u8 *dst, const u8 *src)
 {
-	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
-	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
-
-	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
-		cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
-		return;
-	}
-
-	cipher->cia_decrypt(tfm, dst, src);
+	cipher_crypt_one(tfm, dst, src, true);
 }
+EXPORT_SYMBOL_GPL(crypto_cipher_encrypt_one);
 
-int crypto_init_cipher_ops(struct crypto_tfm *tfm)
+void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
+			       u8 *dst, const u8 *src)
 {
-	struct cipher_tfm *ops = &tfm->crt_cipher;
-	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
-
-	ops->cit_setkey = setkey;
-	ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
-		cipher_encrypt_unaligned : cipher->cia_encrypt;
-	ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
-		cipher_decrypt_unaligned : cipher->cia_decrypt;
-
-	return 0;
+	cipher_crypt_one(tfm, dst, src, false);
 }
+EXPORT_SYMBOL_GPL(crypto_cipher_decrypt_one);