Add PSA interruptible export public-key get num ops API

ChangeLog.d/add-psa-iop-export-public-key.txt

@@ -0,0 +1,3 @@
+Features
+   * Add an interruptible version of export public-key to the PSA interface.
+     See psa_export_public_key_iop_setup() and related functions.

tf-psa-crypto/core/psa_crypto.c

@@ -1676,6 +1676,8 @@ static psa_status_t psa_export_public_key_iop_abort_internal(psa_export_public_k
 
     status = mbedtls_psa_ecp_export_public_key_iop_abort(&operation->ctx);
 
+    memset(&operation->ctx, 0, sizeof(operation->ctx));
+
     operation->id = 0;
 
     return status;
@@ -1684,8 +1686,12 @@ static psa_status_t psa_export_public_key_iop_abort_internal(psa_export_public_k
 
 uint32_t psa_export_public_key_iop_get_num_ops(psa_export_public_key_iop_t *operation)
 {
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    return operation->num_ops;
+#else
     (void) operation;
     return 0;
+#endif
 }
 
 psa_status_t psa_export_public_key_iop_setup(psa_export_public_key_iop_t *operation,
@@ -1694,9 +1700,8 @@ psa_status_t psa_export_public_key_iop_setup(psa_export_public_key_iop_t *operat
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
     psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
-    size_t key_size = 0;
-    psa_key_attributes_t private_key_attributes;
-    psa_key_type_t private_key_type;
+    psa_key_attributes_t key_attributes;
+    psa_key_type_t key_type;
     psa_key_slot_t *slot = NULL;
 
     if (operation->id != 0 || operation->error_occurred) {
@@ -1713,29 +1718,22 @@ psa_status_t psa_export_public_key_iop_setup(psa_export_public_key_iop_t *operat
         goto exit;
     }
 
-    private_key_attributes = slot->attr;
+    key_attributes = slot->attr;
 
-    private_key_type = psa_get_key_type(&private_key_attributes);
+    key_type = psa_get_key_type(&key_attributes);
 
-    if (!PSA_KEY_TYPE_IS_KEY_PAIR(private_key_type)) {
+    if (!PSA_KEY_TYPE_IS_ASYMMETRIC(key_type)) {
         status = PSA_ERROR_INVALID_ARGUMENT;
         goto exit;
     }
 
-    if (!PSA_KEY_TYPE_IS_ECC_KEY_PAIR(private_key_type)) {
-        status = PSA_ERROR_NOT_SUPPORTED;
-        goto exit;
-    }
-
-    key_size = PSA_EXPORT_KEY_OUTPUT_SIZE(private_key_type,
-                                          psa_get_key_bits(&private_key_attributes));
-    if (key_size == 0) {
+    if (!PSA_KEY_TYPE_IS_ECC(key_type)) {
         status = PSA_ERROR_NOT_SUPPORTED;
         goto exit;
     }
 
     status = mbedtls_psa_ecp_export_public_key_iop_setup(&operation->ctx, slot->key.data,
-                                                         slot->key.bytes, &private_key_attributes);
+                                                         slot->key.bytes, &key_attributes);
 
 exit:
     unlock_status = psa_unregister_read_under_mutex(slot);
@@ -1757,12 +1755,35 @@ psa_status_t psa_export_public_key_iop_complete(psa_export_public_key_iop_t *ope
                                                 size_t data_size,
                                                 size_t *data_length)
 {
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (operation->id == 0 || operation->error_occurred) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    status = mbedtls_psa_ecp_export_public_key_iop_complete(&operation->ctx, data, data_size,
+                                                            data_length);
+
+    operation->num_ops = mbedtls_psa_ecp_export_public_key_iop_get_num_ops(&operation->ctx);
+
+    if (status != PSA_OPERATION_INCOMPLETE) {
+        psa_export_public_key_iop_abort_internal(operation);
+
+        if (status != PSA_SUCCESS) {
+            operation->error_occurred = 1;
+        }
+    }
+
+    return status;
+#else
     (void) operation;
     (void) data;
     (void) data_size;
     (void) data_length;
 
-    return PSA_ERROR_NOT_SUPPORTED;
+    return PSA_ERROR_BAD_STATE;
+#endif
 }
 
 psa_status_t psa_export_public_key_iop_abort(psa_export_public_key_iop_t *operation)

tf-psa-crypto/drivers/builtin/src/psa_crypto_ecp.c

@@ -664,19 +664,25 @@ psa_status_t mbedtls_psa_ecp_generate_key_iop_abort(
     return PSA_SUCCESS;
 }
 
+uint32_t mbedtls_psa_ecp_export_public_key_iop_get_num_ops(
+    mbedtls_psa_export_public_key_iop_t *operation)
+{
+    return operation->num_ops;
+}
+
 psa_status_t mbedtls_psa_ecp_export_public_key_iop_setup(
-    mbedtls_psa_export_public_key_iop_operation_t *operation,
-    uint8_t *private_key,
-    size_t private_key_len,
-    const psa_key_attributes_t *private_key_attributes)
+    mbedtls_psa_export_public_key_iop_t *operation,
+    uint8_t *key,
+    size_t key_len,
+    const psa_key_attributes_t *key_attributes)
 {
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
 
     status = mbedtls_psa_ecp_load_representation(
-        psa_get_key_type(private_key_attributes),
-        psa_get_key_bits(private_key_attributes),
-        private_key,
-        private_key_len,
+        psa_get_key_type(key_attributes),
+        psa_get_key_bits(key_attributes),
+        key,
+        key_len,
         &operation->key);
     if (status != PSA_SUCCESS) {
         goto exit;
@@ -689,8 +695,35 @@ psa_status_t mbedtls_psa_ecp_export_public_key_iop_setup(
     return status;
 }
 
+psa_status_t mbedtls_psa_ecp_export_public_key_iop_complete(
+    mbedtls_psa_export_public_key_iop_t *operation,
+    uint8_t *pub_key,
+    size_t pub_key_size,
+    size_t *pub_key_len)
+{
+    int ret = 0;
+
+    if (mbedtls_ecp_is_zero(&operation->key->Q)) {
+        mbedtls_psa_interruptible_set_max_ops(psa_interruptible_get_max_ops());
+
+        ret = mbedtls_ecp_mul_restartable(&operation->key->grp, &operation->key->Q,
+                                          &operation->key->d, &operation->key->grp.G,
+                                          mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE,
+                                          &operation->restart_ctx);
+        operation->num_ops += operation->restart_ctx.ops_done;
+    }
+
+    if (ret == 0) {
+        ret = mbedtls_ecp_write_public_key(operation->key,
+                                           MBEDTLS_ECP_PF_UNCOMPRESSED, pub_key_len,
+                                           pub_key, pub_key_size);
+    }
+
+    return mbedtls_to_psa_error(ret);
+}
+
 psa_status_t mbedtls_psa_ecp_export_public_key_iop_abort(
-    mbedtls_psa_export_public_key_iop_operation_t *operation)
+    mbedtls_psa_export_public_key_iop_t *operation)
 {
     mbedtls_ecp_keypair_free(operation->key);
     mbedtls_free(operation->key);

tf-psa-crypto/drivers/builtin/src/psa_crypto_ecp.h

@@ -120,10 +120,21 @@ 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 Get the total number of ops that an export public-key operation has taken
+ *        Since it's start.
+ *
+ * \param[in] operation                 The \c mbedtls_psa_export_public_key_iop_t to use.
+ *
+ * \return Total number of operations.
+ */
+uint32_t mbedtls_psa_ecp_export_public_key_iop_get_num_ops(
+    mbedtls_psa_export_public_key_iop_t *operation);
+
 /**
  * \brief Setup a new interruptible export public-key operation.
  *
- *  \param[in] operation                 The \c mbedtls_psa_export_public_key_iop_operation_t to use.
+ *  \param[in] operation                 The \c mbedtls_psa_export_public_key_iop_t to use.
  *                                       This must be initialized first.
  *  \param[in] private_key               pointer to private key.
  *  \param[in] private_key_len           size of \p private_key in bytes.
@@ -142,21 +153,46 @@ psa_status_t mbedtls_psa_ecp_export_public_key(
  *
  */
 psa_status_t mbedtls_psa_ecp_export_public_key_iop_setup(
-    mbedtls_psa_export_public_key_iop_operation_t *operation,
+    mbedtls_psa_export_public_key_iop_t *operation,
     uint8_t *private_key,
     size_t private_key_len,
     const psa_key_attributes_t *private_key_attributes);
 
+
+/**
+ * \brief Continue and eventually complete an export public-key operation.
+ *
+ * \param[in] operation                  The \c mbedtls_psa_export_public_key_iop_t to use.
+ *                                       This must be initialized first and
+ *                                       had \c mbedtls_psa_ecp_export_public_key_iop_setup()
+ *                                       called successfully.
+ * \param[out] pub_key                   Buffer where the public key data is to be written.
+ * \param[in]  pub_key_size              Size of the \p pub_key buffer in bytes.
+ * \param[out] pub_key_len               On success, the number of bytes that make up the public key data.
+ *
+ * \retval #PSA_SUCCESS
+ *         The key was exported successfully.
+ * \retval #PSA_ERROR_INVALID_ARGUMENT \emptydescription
+ * \retval #PSA_ERROR_BUFFER_TOO_SMALL \emptydescription
+ * \retval #PSA_ERROR_NOT_SUPPORTED \emptydescription
+ *
+ */
+psa_status_t mbedtls_psa_ecp_export_public_key_iop_complete(
+    mbedtls_psa_export_public_key_iop_t *operation,
+    uint8_t *pub_key,
+    size_t pub_key_size,
+    size_t *pub_key_len);
+
 /**
  * \brief Abort an interruptible export public-key operation.
  *
- * \param[in] operation               The \c mbedtls_psa_export_public_key_iop_operation_t to abort.
+ * \param[in] operation               The \c mbedtls_psa_export_public_key_iop_t to abort.
  *
  * \retval #PSA_SUCCESS
  *         The operation was aborted successfully.
  */
 psa_status_t mbedtls_psa_ecp_export_public_key_iop_abort(
-    mbedtls_psa_export_public_key_iop_operation_t *operation);
+    mbedtls_psa_export_public_key_iop_t *operation);
 
 /**
  * \brief Generate an ECP key.

tf-psa-crypto/include/psa/crypto_builtin_composites.h

@@ -258,7 +258,7 @@ typedef struct {
     /* Make the struct non-empty if algs not supported. */
     unsigned MBEDTLS_PRIVATE(dummy);
 #endif
-} mbedtls_psa_export_public_key_iop_operation_t;
+} mbedtls_psa_export_public_key_iop_t;
 
 #if defined(MBEDTLS_ECP_C) && defined(MBEDTLS_ECP_RESTARTABLE)
 #define MBEDTLS_PSA_EXPORT_PUBLIC_KEY_IOP_INIT { NULL, MBEDTLS_ECP_RESTART_INIT, 0 }

tf-psa-crypto/include/psa/crypto_struct.h

@@ -584,7 +584,7 @@ struct psa_export_public_key_iop_s {
      * any driver (i.e. none of the driver contexts are active).
      */
     unsigned int MBEDTLS_PRIVATE(id);
-    mbedtls_psa_export_public_key_iop_operation_t MBEDTLS_PRIVATE(ctx);
+    mbedtls_psa_export_public_key_iop_t MBEDTLS_PRIVATE(ctx);
     unsigned int MBEDTLS_PRIVATE(error_occurred) : 1;
     uint32_t MBEDTLS_PRIVATE(num_ops);
 #endif