From 0eb76ba29d16df2951d37c54ca279c4e5630b071 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 11 Dec 2020 13:27:15 +0100 Subject: crypto: remove cipher routines from public crypto API The cipher routines in the crypto API are mostly intended for templates implementing skcipher modes generically in software, and shouldn't be used outside of the crypto subsystem. So move the prototypes and all related definitions to a new header file under include/crypto/internal. Also, let's use the new module namespace feature to move the symbol exports into a new namespace CRYPTO_INTERNAL. Signed-off-by: Ard Biesheuvel Acked-by: Eric Biggers Signed-off-by: Herbert Xu --- include/linux/crypto.h | 163 ------------------------------------------------- 1 file changed, 163 deletions(-) (limited to 'include/linux') diff --git a/include/linux/crypto.h b/include/linux/crypto.h index ef90e07c9635..9b55cd6b1f1b 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -636,10 +636,6 @@ struct crypto_tfm { void *__crt_ctx[] CRYPTO_MINALIGN_ATTR; }; -struct crypto_cipher { - struct crypto_tfm base; -}; - struct crypto_comp { struct crypto_tfm base; }; @@ -743,165 +739,6 @@ static inline unsigned int crypto_tfm_ctx_alignment(void) return __alignof__(tfm->__crt_ctx); } -/** - * DOC: Single Block Cipher API - * - * The single block cipher API is used with the ciphers of type - * CRYPTO_ALG_TYPE_CIPHER (listed as type "cipher" in /proc/crypto). - * - * Using the single block cipher API calls, operations with the basic cipher - * primitive can be implemented. These cipher primitives exclude any block - * chaining operations including IV handling. - * - * The purpose of this single block cipher API is to support the implementation - * of templates or other concepts that only need to perform the cipher operation - * on one block at a time. Templates invoke the underlying cipher primitive - * block-wise and process either the input or the output data of these cipher - * operations. - */ - -static inline struct crypto_cipher *__crypto_cipher_cast(struct crypto_tfm *tfm) -{ - return (struct crypto_cipher *)tfm; -} - -/** - * crypto_alloc_cipher() - allocate single block cipher handle - * @alg_name: is the cra_name / name or cra_driver_name / driver name of the - * single block cipher - * @type: specifies the type of the cipher - * @mask: specifies the mask for the cipher - * - * Allocate a cipher handle for a single block cipher. The returned struct - * crypto_cipher is the cipher handle that is required for any subsequent API - * invocation for that single block cipher. - * - * Return: allocated cipher handle in case of success; IS_ERR() is true in case - * of an error, PTR_ERR() returns the error code. - */ -static inline struct crypto_cipher *crypto_alloc_cipher(const char *alg_name, - u32 type, u32 mask) -{ - type &= ~CRYPTO_ALG_TYPE_MASK; - type |= CRYPTO_ALG_TYPE_CIPHER; - mask |= CRYPTO_ALG_TYPE_MASK; - - return __crypto_cipher_cast(crypto_alloc_base(alg_name, type, mask)); -} - -static inline struct crypto_tfm *crypto_cipher_tfm(struct crypto_cipher *tfm) -{ - return &tfm->base; -} - -/** - * crypto_free_cipher() - zeroize and free the single block cipher handle - * @tfm: cipher handle to be freed - */ -static inline void crypto_free_cipher(struct crypto_cipher *tfm) -{ - crypto_free_tfm(crypto_cipher_tfm(tfm)); -} - -/** - * crypto_has_cipher() - Search for the availability of a single block cipher - * @alg_name: is the cra_name / name or cra_driver_name / driver name of the - * single block cipher - * @type: specifies the type of the cipher - * @mask: specifies the mask for the cipher - * - * Return: true when the single block cipher is known to the kernel crypto API; - * false otherwise - */ -static inline int crypto_has_cipher(const char *alg_name, u32 type, u32 mask) -{ - type &= ~CRYPTO_ALG_TYPE_MASK; - type |= CRYPTO_ALG_TYPE_CIPHER; - mask |= CRYPTO_ALG_TYPE_MASK; - - return crypto_has_alg(alg_name, type, mask); -} - -/** - * crypto_cipher_blocksize() - obtain block size for cipher - * @tfm: cipher handle - * - * The block size for the single block cipher referenced with the cipher handle - * tfm 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_cipher_blocksize(struct crypto_cipher *tfm) -{ - return crypto_tfm_alg_blocksize(crypto_cipher_tfm(tfm)); -} - -static inline unsigned int crypto_cipher_alignmask(struct crypto_cipher *tfm) -{ - return crypto_tfm_alg_alignmask(crypto_cipher_tfm(tfm)); -} - -static inline u32 crypto_cipher_get_flags(struct crypto_cipher *tfm) -{ - return crypto_tfm_get_flags(crypto_cipher_tfm(tfm)); -} - -static inline void crypto_cipher_set_flags(struct crypto_cipher *tfm, - u32 flags) -{ - crypto_tfm_set_flags(crypto_cipher_tfm(tfm), flags); -} - -static inline void crypto_cipher_clear_flags(struct crypto_cipher *tfm, - u32 flags) -{ - crypto_tfm_clear_flags(crypto_cipher_tfm(tfm), flags); -} - -/** - * crypto_cipher_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 single block cipher 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_cipher_setkey(struct crypto_cipher *tfm, - const u8 *key, unsigned int keylen); - -/** - * crypto_cipher_encrypt_one() - encrypt one block of plaintext - * @tfm: cipher handle - * @dst: points to the buffer that will be filled with the ciphertext - * @src: buffer holding the plaintext to be encrypted - * - * Invoke the encryption operation of one block. The caller must ensure that - * the plaintext and ciphertext buffers are at least one block in size. - */ -void crypto_cipher_encrypt_one(struct crypto_cipher *tfm, - u8 *dst, const u8 *src); - -/** - * crypto_cipher_decrypt_one() - decrypt one block of ciphertext - * @tfm: cipher handle - * @dst: points to the buffer that will be filled with the plaintext - * @src: buffer holding the ciphertext to be decrypted - * - * Invoke the decryption operation of one block. The caller must ensure that - * the plaintext and ciphertext buffers are at least one block in size. - */ -void crypto_cipher_decrypt_one(struct crypto_cipher *tfm, - u8 *dst, const u8 *src); - static inline struct crypto_comp *__crypto_comp_cast(struct crypto_tfm *tfm) { return (struct crypto_comp *)tfm; -- cgit v1.2.3 From 660d2062190db131d2feaf19914e90f868fe285c Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 13 Jan 2021 10:11:35 +0100 Subject: crypto - shash: reduce minimum alignment of shash_desc structure Unlike many other structure types defined in the crypto API, the 'shash_desc' structure is permitted to live on the stack, which implies its contents may not be accessed by DMA masters. (This is due to the fact that the stack may be located in the vmalloc area, which requires a different virtual-to-physical translation than the one implemented by the DMA subsystem) Our definition of CRYPTO_MINALIGN_ATTR is based on ARCH_KMALLOC_MINALIGN, which may take DMA constraints into account on architectures that support non-cache coherent DMA such as ARM and arm64. In this case, the value is chosen to reflect the largest cacheline size in the system, in order to ensure that explicit cache maintenance as required by non-coherent DMA masters does not affect adjacent, unrelated slab allocations. On arm64, this value is currently set at 128 bytes. This means that applying CRYPTO_MINALIGN_ATTR to struct shash_desc is both unnecessary (as it is never used for DMA), and undesirable, given that it wastes stack space (on arm64, performing the alignment costs 112 bytes in the worst case, and the hole between the 'tfm' and '__ctx' members takes up another 120 bytes, resulting in an increased stack footprint of up to 232 bytes.) So instead, let's switch to the minimum SLAB alignment, which does not take DMA constraints into account. Note that this is a no-op for x86. Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- include/linux/crypto.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 9b55cd6b1f1b..da5e0d74bb2f 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -151,9 +151,12 @@ * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual * declaration) is used to ensure that the crypto_tfm context structure is * aligned correctly for the given architecture so that there are no alignment - * faults for C data types. In particular, this is required on platforms such - * as arm where pointers are 32-bit aligned but there are data types such as - * u64 which require 64-bit alignment. + * faults for C data types. On architectures that support non-cache coherent + * DMA, such as ARM or arm64, it also takes into account the minimal alignment + * that is required to ensure that the context struct member does not share any + * cachelines with the rest of the struct. This is needed to ensure that cache + * maintenance for non-coherent DMA (cache invalidation in particular) does not + * affect data that may be accessed by the CPU concurrently. */ #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN -- cgit v1.2.3