psa: Move xxx_load_representation functions to RSA/ECP specific modules

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
2025-08-08 17:42:09 +03:00 · 2020-11-25 15:25:26 +01:00
parent 3c8ca3ad00
commit 00b7bfc2c4
8 changed files with 359 additions and 205 deletions
--- a/library/psa_crypto_ecp.c
+++ b/library/psa_crypto_ecp.c
@@ -0,0 +1,139 @@
+/*
+ *  PSA ECP layer on top of Mbed TLS crypto
+ */
+/*
+ *  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 "common.h"
+
+#if defined(MBEDTLS_PSA_CRYPTO_C)
+
+#include <psa/crypto.h>
+#include "psa_crypto_core.h"
+#include "psa_crypto_ecp.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include "mbedtls/platform.h"
+#if !defined(MBEDTLS_PLATFORM_C)
+#define mbedtls_calloc calloc
+#define mbedtls_free   free
+#endif
+
+#include <mbedtls/ecp.h>
+#include <mbedtls/error.h>
+
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
+    defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
+psa_status_t mbedtls_psa_ecp_load_representation(
+    psa_key_type_t type, const uint8_t *data, size_t data_length,
+    mbedtls_ecp_keypair **p_ecp )
+{
+    mbedtls_ecp_group_id grp_id = MBEDTLS_ECP_DP_NONE;
+    psa_status_t status;
+    mbedtls_ecp_keypair *ecp = NULL;
+    size_t curve_size = data_length;
+
+    if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) &&
+        PSA_KEY_TYPE_ECC_GET_FAMILY( type ) != PSA_ECC_FAMILY_MONTGOMERY )
+    {
+        /* A Weierstrass public key is represented as:
+         * - The byte 0x04;
+         * - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
+         * - `y_P` as a `ceiling(m/8)`-byte string, big-endian.
+         * So its data length is 2m+1 where m is the curve size in bits.
+         */
+        if( ( data_length & 1 ) == 0 )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        curve_size = data_length / 2;
+
+        /* Montgomery public keys are represented in compressed format, meaning
+         * their curve_size is equal to the amount of input. */
+
+        /* Private keys are represented in uncompressed private random integer
+         * format, meaning their curve_size is equal to the amount of input. */
+    }
+
+    /* Allocate and initialize a key representation. */
+    ecp = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
+    if( ecp == NULL )
+        return( PSA_ERROR_INSUFFICIENT_MEMORY );
+    mbedtls_ecp_keypair_init( ecp );
+
+    /* Load the group. */
+    grp_id = mbedtls_ecc_group_of_psa( PSA_KEY_TYPE_ECC_GET_FAMILY( type ),
+                                       curve_size );
+    if( grp_id == MBEDTLS_ECP_DP_NONE )
+    {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    status = mbedtls_to_psa_error(
+                mbedtls_ecp_group_load( &ecp->grp, grp_id ) );
+    if( status != PSA_SUCCESS )
+        goto exit;
+
+    /* Load the key material. */
+    if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) )
+    {
+        /* Load the public value. */
+        status = mbedtls_to_psa_error(
+            mbedtls_ecp_point_read_binary( &ecp->grp, &ecp->Q,
+                                           data,
+                                           data_length ) );
+        if( status != PSA_SUCCESS )
+            goto exit;
+
+        /* Check that the point is on the curve. */
+        status = mbedtls_to_psa_error(
+            mbedtls_ecp_check_pubkey( &ecp->grp, &ecp->Q ) );
+        if( status != PSA_SUCCESS )
+            goto exit;
+    }
+    else
+    {
+        /* Load and validate the secret value. */
+        status = mbedtls_to_psa_error(
+            mbedtls_ecp_read_key( ecp->grp.id,
+                                  ecp,
+                                  data,
+                                  data_length ) );
+        if( status != PSA_SUCCESS )
+            goto exit;
+    }
+
+    *p_ecp = ecp;
+exit:
+    if( status != PSA_SUCCESS )
+    {
+        mbedtls_ecp_keypair_free( ecp );
+        mbedtls_free( ecp );
+    }
+
+    return( status );
+}
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
+        * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
+
+#endif /* MBEDTLS_PSA_CRYPTO_C */