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authorHerbert Xu <herbert@gondor.apana.org.au>2006-07-30 11:53:01 +1000
committerHerbert Xu <herbert@gondor.apana.org.au>2006-09-21 11:41:50 +1000
commit6d7d684d635ac5a345f075015f2c84169c111c6a (patch)
tree9a1b397fe8db3c14cc69880aba747e50c1a1faa2 /crypto
parent65b75c36f4e8422602826c75c803136e0da94122 (diff)
downloadlinux-linaro-stable-6d7d684d635ac5a345f075015f2c84169c111c6a.tar.gz
[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 <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/api.c60
1 files changed, 60 insertions, 0 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;