Add driver wrapper function for raw key agreement, along with test call for transparent drivers.

Signed-off-by: Aditya Deshpande <aditya.deshpande@arm.com>
diff --git a/tests/include/test/drivers/key_agreement.h b/tests/include/test/drivers/key_agreement.h
new file mode 100644
index 0000000..57de81a
--- /dev/null
+++ b/tests/include/test/drivers/key_agreement.h
@@ -0,0 +1,71 @@
+/*
+ * Test driver for key agreement functions.
+ */
+/*  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifndef PSA_CRYPTO_TEST_DRIVERS_KEY_AGREEMENT_H
+#define PSA_CRYPTO_TEST_DRIVERS_KEY_AGREEMENT_H
+
+#include "mbedtls/build_info.h"
+
+#if defined(PSA_CRYPTO_DRIVER_TEST)
+#include <psa/crypto_driver_common.h>
+
+typedef struct {
+    /* If non-null, on success, copy this to the output. */
+    void *forced_output;
+    size_t forced_output_length;
+    /* If not PSA_SUCCESS, return this error code instead of processing the
+     * function call. */
+    psa_status_t forced_status;
+    /* Count the amount of times one of the signature driver functions is called. */
+    unsigned long hits;
+} mbedtls_test_driver_key_agreement_hooks_t;
+
+#define MBEDTLS_TEST_DRIVER_KEY_AGREEMENT_INIT { NULL, 0, PSA_SUCCESS, 0 }
+static inline mbedtls_test_driver_key_agreement_hooks_t
+    mbedtls_test_driver_key_agreement_hooks_init( void )
+{
+    const mbedtls_test_driver_key_agreement_hooks_t
+        v = MBEDTLS_TEST_DRIVER_KEY_AGREEMENT_INIT;
+    return( v );
+}
+
+psa_status_t mbedtls_test_transparent_key_agreement(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer,
+    size_t key_buffer_size,
+    psa_algorithm_t alg,
+    const uint8_t *peer_key,
+    size_t peer_key_length,
+    uint8_t *shared_secret,
+    size_t shared_secret_size,
+    size_t *shared_secret_length );
+
+psa_status_t mbedtls_test_opaque_key_agreement(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer,
+    size_t key_buffer_size,
+    psa_algorithm_t alg,
+    const uint8_t *peer_key,
+    size_t peer_key_length,
+    uint8_t *shared_secret,
+    size_t shared_secret_size,
+    size_t *shared_secret_length );
+
+#endif /*PSA_CRYPTO_DRIVER_TEST */
+#endif /* PSA_CRYPTO_TEST_DRIVERS_KEY_AGREEMENT_H */
\ No newline at end of file
diff --git a/tests/include/test/drivers/test_driver.h b/tests/include/test/drivers/test_driver.h
index 098b21a..0bfeb66 100644
--- a/tests/include/test/drivers/test_driver.h
+++ b/tests/include/test/drivers/test_driver.h
@@ -29,5 +29,6 @@
 #include "test/drivers/key_management.h"
 #include "test/drivers/signature.h"
 #include "test/drivers/asymmetric_encryption.h"
+#include "test/drivers/key_agreement.h"
 
 #endif /* PSA_CRYPTO_TEST_DRIVER_H */
diff --git a/tests/src/drivers/test_driver_key_agreement.c b/tests/src/drivers/test_driver_key_agreement.c
new file mode 100644
index 0000000..40681c3
--- /dev/null
+++ b/tests/src/drivers/test_driver_key_agreement.c
@@ -0,0 +1,73 @@
+/*
+ * Test driver for key agreement functions.
+ */
+/*  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <test/helpers.h>
+
+#include "psa/crypto.h"
+#include "psa_crypto_core.h"
+
+#include "test/drivers/key_agreement.h"
+#include "test/drivers/test_driver.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_PSA_CRYPTO_DRIVERS) && defined(PSA_CRYPTO_DRIVER_TEST)
+
+mbedtls_test_driver_key_agreement_hooks_t
+    mbedtls_test_driver_key_agreement_hooks = MBEDTLS_TEST_DRIVER_KEY_AGREEMENT_INIT;
+
+psa_status_t mbedtls_test_transparent_key_agreement(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer,
+    size_t key_buffer_size,
+    psa_algorithm_t alg,
+    const uint8_t *peer_key,
+    size_t peer_key_length,
+    uint8_t *shared_secret,
+    size_t shared_secret_size,
+    size_t *shared_secret_length )
+{
+    if( mbedtls_test_driver_key_agreement_hooks.forced_status != PSA_SUCCESS )
+        return( mbedtls_test_driver_key_agreement_hooks.forced_status );
+
+    if( mbedtls_test_driver_key_agreement_hooks.forced_output != NULL )
+    {
+        if( mbedtls_test_driver_key_agreement_hooks.forced_output_length > shared_secret_size )
+            return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+        memcpy( shared_secret, mbedtls_test_driver_key_agreement_hooks.forced_output,
+                mbedtls_test_driver_key_agreement_hooks.forced_output_length );
+        *shared_secret_length = mbedtls_test_driver_key_agreement_hooks.forced_output_length;
+
+        return( PSA_SUCCESS );
+    }
+
+    return( psa_key_agreement_raw_builtin( 
+                attributes,
+                key_buffer,
+                key_buffer_size,
+                alg,
+                peer_key,
+                peer_key_length,
+                shared_secret,
+                shared_secret_size,
+                shared_secret_length ) );
+}
+
+#endif /* MBEDTLS_PSA_CRYPTO_DRIVERS && PSA_CRYPTO_DRIVER_TEST */
\ No newline at end of file