KPP mechanisms like DH require a parameter set to be provided by the
caller. That parameter set may be provided by the crypto_kpp_set_secret
function. Yet, the parameters hare handled independently from the secret
key which implies that they should be able to be set independently from
the key.
The new API allows KPP mechanisms to register a callback allowing to set
such parameters.
Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>
---
Documentation/crypto/api-kpp.rst | 2 +-
include/crypto/kpp.h | 28 ++++++++++++++++++++++++++++
2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/Documentation/crypto/api-kpp.rst b/Documentation/crypto/api-kpp.rst
index 7d86ab9..7b2c0d4 100644
--- a/Documentation/crypto/api-kpp.rst
+++ b/Documentation/crypto/api-kpp.rst
@@ -11,7 +11,7 @@ Key-agreement Protocol Primitives (KPP) Cipher API
:doc: Generic Key-agreement Protocol Primitives API
.. kernel-doc:: include/crypto/kpp.h
- :functions: crypto_alloc_kpp crypto_free_kpp crypto_kpp_set_secret crypto_kpp_generate_public_key crypto_kpp_compute_shared_secret crypto_kpp_maxsize
+ :functions: crypto_alloc_kpp crypto_free_kpp crypto_kpp_set_params crypto_kpp_set_secret crypto_kpp_generate_public_key crypto_kpp_compute_shared_secret crypto_kpp_maxsize
Key-agreement Protocol Primitives (KPP) Cipher Request Handle
-------------------------------------------------------------
diff --git a/include/crypto/kpp.h b/include/crypto/kpp.h
index ce8e1f7..5931364 100644
--- a/include/crypto/kpp.h
+++ b/include/crypto/kpp.h
@@ -51,6 +51,9 @@ struct crypto_kpp {
/**
* struct kpp_alg - generic key-agreement protocol primitives
*
+ * @set_params: Function allows the caller to set the parameters
+ * separately from the key. The format of the parameters
+ * is protocol specific.
* @set_secret: Function invokes the protocol specific function to
* store the secret private key along with parameters.
* The implementation knows how to decode thie buffer
@@ -74,6 +77,8 @@ struct crypto_kpp {
* @base: Common crypto API algorithm data structure
*/
struct kpp_alg {
+ int (*set_params)(struct crypto_kpp *tfm, const void *buffer,
+ unsigned int len);
int (*set_secret)(struct crypto_kpp *tfm, const void *buffer,
unsigned int len);
int (*generate_public_key)(struct kpp_request *req);
@@ -259,6 +264,29 @@ struct kpp_secret {
};
/**
+ * crypto_kpp_set_params() - Set parameters needed for kpp operation
+ *
+ * Function invokes the specific kpp operation for a given alg.
+ *
+ * @tfm: tfm handle
+ * @buffer: Buffer holding the protocol specific representation of the
+ * parameters (e.g. PKCS#3 DER for DH)
+ * @len: Length of the parameter buffer.
+ *
+ * Return: zero on success; error code in case of error
+ */
+static inline int crypto_kpp_set_params(struct crypto_kpp *tfm,
+ const void *buffer, unsigned int len)
+{
+ struct kpp_alg *alg = crypto_kpp_alg(tfm);
+
+ if (alg->set_params)
+ return alg->set_params(tfm, buffer, len);
+ else
+ return -EOPNOTSUPP;
+}
+
+/**
* crypto_kpp_set_secret() - Invoke kpp operation
*
* Function invokes the specific kpp operation for a given alg.
--
2.9.3
