From 6d7d684d635ac5a345f075015f2c84169c111c6a Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 30 Jul 2006 11:53:01 +1000 Subject: [PATCH] [CRYPTO] api: Added crypto_alloc_base Up until now all crypto transforms have been of the same type, struct crypto_tfm, regardless of whether they are ciphers, digests, or other types. As a result of that, we check the types at run-time before each crypto operation. This is rather cumbersome. We could instead use different C types for each crypto type to ensure that the correct types are used at compile time. That is, we would have crypto_cipher/crypto_digest instead of just crypto_tfm. The appropriate type would then be required for the actual operations such as crypto_digest_digest. Now that we have the type/mask fields when looking up algorithms, it is easy to request for an algorithm of the precise type that the user wants. However, crypto_alloc_tfm currently does not expose these new attributes. This patch introduces the function crypto_alloc_base which will carry these new parameters. It will be renamed to crypto_alloc_tfm once all existing users have been converted. Signed-off-by: Herbert Xu --- crypto/api.c | 60 ++++++++++++++++++++++++++++++++++++++++++ include/linux/crypto.h | 14 +++------- 2 files changed, 63 insertions(+), 11 deletions(-) diff --git a/crypto/api.c b/crypto/api.c index 1e4692a13474..bc4b7901acdf 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -372,6 +372,66 @@ struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags) return tfm; } +/* + * crypto_alloc_base - Locate algorithm and allocate transform + * @alg_name: Name of algorithm + * @type: Type of algorithm + * @mask: Mask for type comparison + * + * crypto_alloc_base() will first attempt to locate an already loaded + * algorithm. If that fails and the kernel supports dynamically loadable + * modules, it will then attempt to load a module of the same name or + * alias. If that fails it will send a query to any loaded crypto manager + * to construct an algorithm on the fly. A refcount is grabbed on the + * algorithm which is then associated with the new transform. + * + * The returned transform is of a non-determinate type. Most people + * should use one of the more specific allocation functions such as + * crypto_alloc_blkcipher. + * + * In case of error the return value is an error pointer. + */ +struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask) +{ + struct crypto_tfm *tfm; + int err; + + for (;;) { + struct crypto_alg *alg; + + alg = crypto_alg_mod_lookup(alg_name, type, mask); + err = PTR_ERR(alg); + tfm = ERR_PTR(err); + if (IS_ERR(alg)) + goto err; + + tfm = __crypto_alloc_tfm(alg, 0); + if (!IS_ERR(tfm)) + break; + + crypto_mod_put(alg); + err = PTR_ERR(tfm); + +err: + if (err != -EAGAIN) + break; + if (signal_pending(current)) { + err = -EINTR; + break; + } + }; + + return tfm; +} +EXPORT_SYMBOL_GPL(crypto_alloc_base); + +/* + * crypto_free_tfm - Free crypto transform + * @tfm: Transform to free + * + * crypto_free_tfm() frees up the transform and any associated resources, + * then drops the refcount on the associated algorithm. + */ void crypto_free_tfm(struct crypto_tfm *tfm) { struct crypto_alg *alg; diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 530dc4bf363c..6847ab0ea30e 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -194,8 +194,8 @@ static inline int crypto_alg_available(const char *name, u32 flags) /* * Transforms: user-instantiated objects which encapsulate algorithms - * and core processing logic. Managed via crypto_alloc_tfm() and - * crypto_free_tfm(), as well as the various helpers below. + * and core processing logic. Managed via crypto_alloc_*() and + * crypto_free_*(), as well as the various helpers below. */ struct cipher_tfm { @@ -278,16 +278,8 @@ struct crypto_attr_alg { * Transform user interface. */ -/* - * crypto_alloc_tfm() will first attempt to locate an already loaded algorithm. - * If that fails and the kernel supports dynamically loadable modules, it - * will then attempt to load a module of the same name or alias. A refcount - * is grabbed on the algorithm which is then associated with the new transform. - * - * crypto_free_tfm() frees up the transform and any associated resources, - * then drops the refcount on the associated algorithm. - */ struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags); +struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask); void crypto_free_tfm(struct crypto_tfm *tfm); /* -- 2.20.1