Merge branch 'Mbed-TLS:development' into threadsafe-key-locking
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index beafc48..43b597c 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -954,7 +954,7 @@
error:
*p_slot = NULL;
- psa_unregister_read(slot);
+ psa_unregister_read_under_mutex(slot);
return status;
}
@@ -986,7 +986,7 @@
}
if (psa_key_lifetime_is_external((*p_slot)->attr.lifetime)) {
- psa_unregister_read(*p_slot);
+ psa_unregister_read_under_mutex(*p_slot);
*p_slot = NULL;
return PSA_ERROR_NOT_SUPPORTED;
}
@@ -1303,7 +1303,7 @@
psa_reset_key_attributes(attributes);
}
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
@@ -1399,7 +1399,7 @@
slot->key.data, slot->key.bytes,
data, data_size, data_length);
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
@@ -1513,7 +1513,7 @@
data, data_size, data_length);
exit:
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
@@ -2185,7 +2185,7 @@
psa_fail_key_creation(target_slot, driver);
}
- unlock_status = psa_unregister_read(source_slot);
+ unlock_status = psa_unregister_read_under_mutex(source_slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
@@ -2692,7 +2692,7 @@
psa_wipe_tag_output_buffer(mac, status, mac_size, *mac_length);
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
@@ -2836,7 +2836,7 @@
psa_wipe_tag_output_buffer(signature, status, signature_size,
*signature_length);
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
@@ -2884,7 +2884,7 @@
signature, signature_length);
}
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
@@ -3151,7 +3151,7 @@
alg, input, input_length, salt, salt_length,
output, output_size, output_length);
exit:
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
@@ -3203,7 +3203,7 @@
output, output_size, output_length);
exit:
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
@@ -4274,7 +4274,7 @@
output_size - default_iv_length, output_length);
exit:
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
if (status == PSA_SUCCESS) {
status = unlock_status;
}
@@ -4335,7 +4335,7 @@
output, output_size, output_length);
exit:
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
if (status == PSA_SUCCESS) {
status = unlock_status;
}
@@ -4461,7 +4461,7 @@
}
exit:
- psa_unregister_read(slot);
+ psa_unregister_read_under_mutex(slot);
return status;
}
@@ -4516,7 +4516,7 @@
}
exit:
- psa_unregister_read(slot);
+ psa_unregister_read_under_mutex(slot);
return status;
}
@@ -7220,7 +7220,7 @@
*output_length = output_size;
}
- unlock_status = psa_unregister_read(slot);
+ unlock_status = psa_unregister_read_under_mutex(slot);
return (status == PSA_SUCCESS) ? unlock_status : status;
}
diff --git a/library/psa_crypto_slot_management.c b/library/psa_crypto_slot_management.c
index 47ace35..53ebf31 100644
--- a/library/psa_crypto_slot_management.c
+++ b/library/psa_crypto_slot_management.c
@@ -70,6 +70,9 @@
* On success, the function locks the key slot. It is the responsibility of
* the caller to unlock the key slot when it does not access it anymore.
*
+ * If multi-threading is enabled, the caller must hold the
+ * global key slot mutex.
+ *
* \param key Key identifier to query.
* \param[out] p_slot On success, `*p_slot` contains a pointer to the
* key slot containing the description of the key
@@ -94,16 +97,14 @@
if (psa_key_id_is_volatile(key_id)) {
slot = &global_data.key_slots[key_id - PSA_KEY_ID_VOLATILE_MIN];
- /*
- * Check if both the PSA key identifier key_id and the owner
- * identifier of key match those of the key slot.
- *
- * Note that, if the key slot is not occupied, its PSA key identifier
- * is equal to zero. This is an invalid value for a PSA key identifier
- * and thus cannot be equal to the valid PSA key identifier key_id.
- */
- status = mbedtls_svc_key_id_equal(key, slot->attr.id) ?
- PSA_SUCCESS : PSA_ERROR_DOES_NOT_EXIST;
+ /* Check if both the PSA key identifier key_id and the owner
+ * identifier of key match those of the key slot. */
+ if ((slot->state == PSA_SLOT_FULL) &&
+ (mbedtls_svc_key_id_equal(key, slot->attr.id))) {
+ status = PSA_SUCCESS;
+ } else {
+ status = PSA_ERROR_DOES_NOT_EXIST;
+ }
} else {
if (!psa_is_valid_key_id(key, 1)) {
return PSA_ERROR_INVALID_HANDLE;
@@ -248,11 +249,6 @@
data = (psa_se_key_data_storage_t *) key_data;
status = psa_copy_key_material_into_slot(
slot, data->slot_number, sizeof(data->slot_number));
-
- if (status == PSA_SUCCESS) {
- status = psa_key_slot_state_transition(slot, PSA_SLOT_FILLING,
- PSA_SLOT_FULL);
- }
goto exit;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
@@ -262,9 +258,6 @@
goto exit;
}
- status = psa_key_slot_state_transition(slot, PSA_SLOT_FILLING,
- PSA_SLOT_FULL);
-
exit:
psa_free_persistent_key_data(key_data, key_data_length);
return status;
@@ -337,9 +330,6 @@
/* Copy actual key length and core attributes into the slot on success */
slot->key.bytes = key_buffer_length;
slot->attr = attributes.core;
-
- status = psa_key_slot_state_transition(slot, PSA_SLOT_FILLING,
- PSA_SLOT_FULL);
exit:
if (status != PSA_SUCCESS) {
psa_remove_key_data_from_memory(slot);
@@ -358,12 +348,24 @@
return PSA_ERROR_BAD_STATE;
}
+#if defined(MBEDTLS_THREADING_C)
+ /* If the key is persistent and not loaded, we cannot unlock the mutex
+ * between checking if the key is loaded and setting the slot as FULL,
+ * as otherwise another thread may load and then destroy the key
+ * in the meantime. */
+ PSA_THREADING_CHK_RET(mbedtls_mutex_lock(
+ &mbedtls_threading_key_slot_mutex));
+#endif
/*
* On success, the pointer to the slot is passed directly to the caller
* thus no need to unlock the key slot here.
*/
status = psa_get_and_lock_key_slot_in_memory(key, p_slot);
if (status != PSA_ERROR_DOES_NOT_EXIST) {
+#if defined(MBEDTLS_THREADING_C)
+ PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+ &mbedtls_threading_key_slot_mutex));
+#endif
return status;
}
@@ -374,6 +376,10 @@
status = psa_reserve_free_key_slot(&volatile_key_id, p_slot);
if (status != PSA_SUCCESS) {
+#if defined(MBEDTLS_THREADING_C)
+ PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+ &mbedtls_threading_key_slot_mutex));
+#endif
return status;
}
@@ -407,10 +413,15 @@
status = psa_register_read(*p_slot);
}
- return status;
#else /* MBEDTLS_PSA_CRYPTO_STORAGE_C || MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS */
- return PSA_ERROR_INVALID_HANDLE;
+ status = PSA_ERROR_INVALID_HANDLE;
#endif /* MBEDTLS_PSA_CRYPTO_STORAGE_C || MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS */
+
+#if defined(MBEDTLS_THREADING_C)
+ PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+ &mbedtls_threading_key_slot_mutex));
+#endif
+ return status;
}
psa_status_t psa_unregister_read(psa_key_slot_t *slot)
@@ -447,6 +458,21 @@
return PSA_ERROR_CORRUPTION_DETECTED;
}
+psa_status_t psa_unregister_read_under_mutex(psa_key_slot_t *slot)
+{
+ psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+#if defined(MBEDTLS_THREADING_C)
+ PSA_THREADING_CHK_RET(mbedtls_mutex_lock(
+ &mbedtls_threading_key_slot_mutex));
+#endif
+ status = psa_unregister_read(slot);
+#if defined(MBEDTLS_THREADING_C)
+ PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+ &mbedtls_threading_key_slot_mutex));
+#endif
+ return status;
+}
+
psa_status_t psa_validate_key_location(psa_key_lifetime_t lifetime,
psa_se_drv_table_entry_t **p_drv)
{
diff --git a/library/psa_crypto_slot_management.h b/library/psa_crypto_slot_management.h
index 002429b..c6ba68b 100644
--- a/library/psa_crypto_slot_management.h
+++ b/library/psa_crypto_slot_management.h
@@ -200,6 +200,27 @@
*/
psa_status_t psa_unregister_read(psa_key_slot_t *slot);
+/** Wrap a call to psa_unregister_read in the global key slot mutex.
+ *
+ * If threading is disabled, this simply calls psa_unregister_read.
+ *
+ * \note To ease the handling of errors in retrieving a key slot
+ * a NULL input pointer is valid, and the function returns
+ * successfully without doing anything in that case.
+ *
+ * \param[in] slot The key slot.
+ * \retval #PSA_SUCCESS
+ * \p slot is NULL or the key slot reader counter has been
+ * decremented (and potentially wiped) successfully.
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * The slot's state was neither PSA_SLOT_FULL nor
+ * PSA_SLOT_PENDING_DELETION.
+ * Or a wipe was attempted and the slot's state was not
+ * PSA_SLOT_PENDING_DELETION.
+ * Or registered_readers was equal to 0.
+ */
+psa_status_t psa_unregister_read_under_mutex(psa_key_slot_t *slot);
+
/** Test whether a lifetime designates a key in an external cryptoprocessor.
*
* \param lifetime The lifetime to test.