cryptodev: formalize key wrap method in API

The Key Wrap approach is used by applications in order to protect keys
located in untrusted storage or transmitted over untrusted
communications networks. The constructions are typically built from
standard primitives such as block ciphers and cryptographic hash
functions.

The Key Wrap method and its parameters are a secret between the keys
provider and the device, means that the device is preconfigured for
this method using very secured way.

The key wrap method may change the key length and layout.

Add a description for the cipher transformation key to allow wrapped key
to be forwarded by the same API.

Add a new feature flag RTE_CRYPTODEV_FF_CIPHER_WRAPPED_KEY to be enabled
by PMDs support wrapped key in cipher trasformation.

Signed-off-by: Matan Azrad <matan@nvidia.com>
Acked-by: Akhil Goyal <gakhil@marvell.com>

doc/guides/cryptodevs/features/default.ini

@@ -32,6 +32,7 @@ Symmetric sessionless  =
 Non-Byte aligned data  =
 Sym raw data path API  =
 Cipher multiple data units =
+Cipher wrapped key     =
 
 ;
 ; Supported crypto algorithms of a default crypto driver.

doc/guides/cryptodevs/overview.rst

@@ -49,6 +49,9 @@ Supported Feature Flags
    - "CIPHER_MULTIPLE_DATA_UNITS" feature flag means PMD support operations
       on multiple data-units message.
 
+   - "CIPHER_WRAPPED_KEY" feature flag means PMD support wrapped key in cipher
+      xform.
+
 
 Supported Cipher Algorithms
 ---------------------------

doc/guides/rel_notes/release_21_05.rst

@@ -156,6 +156,11 @@ New Features
   data-units for AES-XTS algorithm, the data-unit length should be set in the
   transformation. A capability for it was added too.
 
+* **Added a cryptodev feature flag to support cipher wrapped keys.**
+
+  A new feature flag has been added to allow application to provide
+  cipher wrapped keys in session xforms.
+
 * **Updated the OCTEON TX crypto PMD.**
 
   * Added support for DIGEST_ENCRYPTED mode in OCTEON TX crypto PMD.

lib/librte_cryptodev/rte_crypto_sym.h

@@ -203,6 +203,14 @@ struct rte_crypto_cipher_xform {
 		uint16_t length;	/**< key length in bytes */
 	} key;
 	/**< Cipher key
+	 *
+	 * In case the PMD supports RTE_CRYPTODEV_FF_CIPHER_WRAPPED_KEY, the
+	 * original key data provided may be wrapped(encrypted) using key wrap
+	 * algorithm such as AES key wrap (rfc3394) and hence length of the key
+	 * may increase beyond the PMD advertised supported key size.
+	 * PMD shall validate the key length and report EMSGSIZE error while
+	 * configuring the session and application can skip checking the
+	 * capability key length in such cases.
 	 *
 	 * For the RTE_CRYPTO_CIPHER_AES_F8 mode of operation, key.data will
 	 * point to a concatenation of the AES encryption key followed by a

lib/librte_cryptodev/rte_cryptodev.c

@@ -619,6 +619,8 @@ rte_cryptodev_get_feature_name(uint64_t flag)
 		return "NON_BYTE_ALIGNED_DATA";
 	case RTE_CRYPTODEV_FF_CIPHER_MULTIPLE_DATA_UNITS:
 		return "CIPHER_MULTIPLE_DATA_UNITS";
+	case RTE_CRYPTODEV_FF_CIPHER_WRAPPED_KEY:
+		return "CIPHER_WRAPPED_KEY";
 	default:
 		return NULL;
 	}

lib/librte_cryptodev/rte_cryptodev.h

@@ -477,6 +477,8 @@ rte_cryptodev_asym_get_xform_enum(enum rte_crypto_asym_xform_type *xform_enum,
 /**< Support accelerator specific symmetric raw data-path APIs */
 #define RTE_CRYPTODEV_FF_CIPHER_MULTIPLE_DATA_UNITS	(1ULL << 25)
 /**< Support operations on multiple data-units message */
+#define RTE_CRYPTODEV_FF_CIPHER_WRAPPED_KEY		(1ULL << 26)
+/**< Support wrapped key in cipher xform  */
 
 /**
  * Get the name of a crypto device feature flag