Re: [PATCH 4/8] crypto: KPP - add API crypto_kpp_set_params

[Stephan Müller]

Am Mittwoch, 19. April 2017, 16:51:54 CEST schrieb Benedetto, Salvatore:

Hi Salvatore,

> Hi Stephan,
> 
> > -Original Message-
> > From: keyrings-ow...@vger.kernel.org [mailto:keyrings-
> > ow...@vger.kernel.org] On Behalf Of Stephan Müller
> > Sent: Wednesday, April 19, 2017 12:06 AM
> > To: linux-crypto@vger.kernel.org
> > Cc: keyri...@vger.kernel.org
> > Subject: [PATCH 4/8] crypto: KPP - add API crypto_kpp_set_params
> > 
> > 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 <smuel...@chronox.de>
> > ---
> > 
> >  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.
> > 
> > 

RE: [PATCH 4/8] crypto: KPP - add API crypto_kpp_set_params

[Benedetto, Salvatore]

Hi Stephan,

> -Original Message-
> From: keyrings-ow...@vger.kernel.org [mailto:keyrings-
> ow...@vger.kernel.org] On Behalf Of Stephan Müller
> Sent: Wednesday, April 19, 2017 12:06 AM
> To: linux-crypto@vger.kernel.org
> Cc: keyri...@vger.kernel.org
> Subject: [PATCH 4/8] crypto: KPP - add API crypto_kpp_set_params
> 
> 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 <smuel...@chronox.de>
> ---
>  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

I'm not really in favor of having two ways for setting the params.
As you are probably aware, PKCS3 and set_params was my intial
approach, but then Herbert suggested a lighter approach like rtnetlink
which I actually prefer.

Can't you expose that through AF_ALG?

Regards,
Salvatore

[PATCH 4/8] crypto: KPP - add API crypto_kpp_set_params

[Stephan Müller]

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 
---
 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