Move ECP key generation code to the PSA ECP specific C file

Signed-off-by: Ronald Cron <ronald.cron@arm.com>

library/psa_crypto.c

@@ -34,6 +34,7 @@
 #include "psa_crypto_driver_wrappers.h"
 #include "psa_crypto_ecp.h"
 #include "psa_crypto_rsa.h"
+#include "psa_crypto_ecp.h"
 #if defined(MBEDTLS_PSA_CRYPTO_SE_C)
 #include "psa_crypto_se.h"
 #endif
@@ -6053,38 +6054,10 @@ psa_status_t psa_generate_key_internal(
 #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR)
     if ( PSA_KEY_TYPE_IS_ECC( type ) && PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
     {
-        psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY( type );
+        return( mbedtls_psa_ecp_generate_key( attributes,
-        mbedtls_ecp_group_id grp_id =
+                                              key_buffer,
-            mbedtls_ecc_group_of_psa( curve, attributes->core.bits, 0 );
+                                              key_buffer_size,
-
+                                              key_buffer_length ) );
-        const mbedtls_ecp_curve_info *curve_info =
-            mbedtls_ecp_curve_info_from_grp_id( grp_id );
-        mbedtls_ecp_keypair ecp;
-        int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-        if( attributes->domain_parameters_size != 0 )
-            return( PSA_ERROR_NOT_SUPPORTED );
-        if( grp_id == MBEDTLS_ECP_DP_NONE || curve_info == NULL )
-            return( PSA_ERROR_NOT_SUPPORTED );
-
-        mbedtls_ecp_keypair_init( &ecp );
-        ret = mbedtls_ecp_gen_key( grp_id, &ecp,
-                                   mbedtls_psa_get_random,
-                                   MBEDTLS_PSA_RANDOM_STATE );
-        if( ret != 0 )
-        {
-            mbedtls_ecp_keypair_free( &ecp );
-            return( mbedtls_to_psa_error( ret ) );
-        }
-
-        status = mbedtls_to_psa_error(
-            mbedtls_ecp_write_key( &ecp, key_buffer, key_buffer_size ) );
-
-        mbedtls_ecp_keypair_free( &ecp );
-
-        if( status == PSA_SUCCESS )
-            *key_buffer_length = key_buffer_size;
-
-        return( status );
     }
     else
 #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) */

library/psa_crypto_ecp.c

@@ -292,6 +292,52 @@ static psa_status_t ecp_export_public_key(
 #endif /* defined(BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
         * defined(BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
 
+#if defined(BUILTIN_KEY_TYPE_ECC_KEY_PAIR)
+psa_status_t mbedtls_psa_ecp_generate_key(
+    const psa_key_attributes_t *attributes,
+    uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length )
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+    psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY(
+                                 attributes->core.type );
+    mbedtls_ecp_group_id grp_id =
+         mbedtls_ecc_group_of_psa( curve, attributes->core.bits, 0 );
+
+    const mbedtls_ecp_curve_info *curve_info =
+        mbedtls_ecp_curve_info_from_grp_id( grp_id );
+    mbedtls_ecp_keypair ecp;
+
+    if( attributes->domain_parameters_size != 0 )
+        return( PSA_ERROR_NOT_SUPPORTED );
+
+    if( grp_id == MBEDTLS_ECP_DP_NONE || curve_info == NULL )
+        return( PSA_ERROR_NOT_SUPPORTED );
+
+    mbedtls_ecp_keypair_init( &ecp );
+    ret = mbedtls_ecp_gen_key( grp_id, &ecp,
+                               mbedtls_psa_get_random,
+                               MBEDTLS_PSA_RANDOM_STATE );
+    if( ret != 0 )
+    {
+        mbedtls_ecp_keypair_free( &ecp );
+        return( mbedtls_to_psa_error( ret ) );
+    }
+
+    status = mbedtls_to_psa_error(
+        mbedtls_ecp_write_key( &ecp, key_buffer, key_buffer_size ) );
+
+    mbedtls_ecp_keypair_free( &ecp );
+
+    if( status == PSA_SUCCESS )
+        *key_buffer_length = key_buffer_size;
+
+    return( status );
+}
+#endif /* defined(BUILTIN_KEY_TYPE_ECC_KEY_PAIR) */
+
+
 #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
     defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
 

library/psa_crypto_ecp.h

@@ -123,6 +123,29 @@ psa_status_t mbedtls_psa_ecp_export_public_key(
     const uint8_t *key_buffer, size_t key_buffer_size,
     uint8_t *data, size_t data_size, size_t *data_length );
 
+/**
+ * \brief Generate an ECP key.
+ *
+ * \note The signature of the function is that of a PSA driver generate_key
+ *       entry point.
+ *
+ * \param[in]  attributes         The attributes for the ECP key to generate.
+ * \param[out] key_buffer         Buffer where the key data is to be written.
+ * \param[in]  key_buffer_size    Size of \p key_buffer in bytes.
+ * \param[out] key_buffer_length  On success, the number of bytes written in
+ *                                \p key_buffer.
+ *
+ * \retval #PSA_SUCCESS
+ *         The key was successfully generated.
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ *         Key length or type not supported.
+ * \retval #PSA_ERROR_BUFFER_TOO_SMALL
+ *         The size of \p key_buffer is too small.
+ */
+psa_status_t mbedtls_psa_ecp_generate_key(
+    const psa_key_attributes_t *attributes,
+    uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length );
+
 /*
  * BEYOND THIS POINT, TEST DRIVER ENTRY POINTS ONLY.
  */