path: root/include/crypto
diff options
authorEric Biggers <ebiggers@google.com>2020-05-01 22:31:03 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2020-05-08 15:32:12 +1000
commit822a98b862d5b511826765d64ddf18192fc5b694 (patch)
tree292c80ad704e481f41ad14cedf96abe8d918012f /include/crypto
parentcrypto: lib/sha256 - return void (diff)
crypto: hash - introduce crypto_shash_tfm_digest()
Currently the simplest use of the shash API is to use crypto_shash_digest() to digest a whole buffer. However, this still requires allocating a hash descriptor (struct shash_desc). Many users don't really want to preallocate one and instead just use a one-off descriptor on the stack like the following: { SHASH_DESC_ON_STACK(desc, tfm); int err; desc->tfm = tfm; err = crypto_shash_digest(desc, data, len, out); shash_desc_zero(desc); } Wrap this in a new helper function crypto_shash_tfm_digest() that can be used instead of the above. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include/crypto')
1 files changed, 19 insertions, 0 deletions
diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index cee446c59497..4829d2367eda 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -856,6 +856,25 @@ int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out);
+ * crypto_shash_tfm_digest() - calculate message digest for buffer
+ * @tfm: hash transformation object
+ * @data: see crypto_shash_update()
+ * @len: see crypto_shash_update()
+ * @out: see crypto_shash_final()
+ *
+ * This is a simplified version of crypto_shash_digest() for users who don't
+ * want to allocate their own hash descriptor (shash_desc). Instead,
+ * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
+ * directly, and it allocates a hash descriptor on the stack internally.
+ * Note that this stack allocation may be fairly large.
+ *
+ * Context: Any context.
+ * Return: 0 on success; < 0 if an error occurred.
+ */
+int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
+ unsigned int len, u8 *out);
* crypto_shash_export() - extract operational state for message digest
* @desc: reference to the operational state handle whose state is exported
* @out: output buffer of sufficient size that can hold the hash state