1 /*
2  * Copyright (c) 2019-2023, Arm Limited. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  */
7 /**
8  * \file psa/crypto_compat.h
9  *
10  * \brief PSA cryptography module: Backward compatibility aliases
11  *
12  * This header declares alternative names for macro and functions.
13  * New application code should not use these names.
14  * These names may be removed in a future version of Mbed Crypto.
15  *
16  * \note This file may not be included directly. Applications must
17  * include psa/crypto.h.
18  */
19 
20 #ifndef PSA_CRYPTO_COMPAT_H
21 #define PSA_CRYPTO_COMPAT_H
22 
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26 
27 /*
28  * To support both openless APIs and psa_open_key() temporarily, define
29  * psa_key_handle_t to be equal to mbedtls_svc_key_id_t. Do not mark the
30  * type and its utility macros and functions deprecated yet. This will be done
31  * in a subsequent phase.
32  */
33 typedef mbedtls_svc_key_id_t psa_key_handle_t;
34 
35 #define PSA_KEY_HANDLE_INIT MBEDTLS_SVC_KEY_ID_INIT
36 
37 /** Check whether a handle is null.
38  *
39  * \param handle  Handle
40  *
41  * \return Non-zero if the handle is null, zero otherwise.
42  */
psa_key_handle_is_null(psa_key_handle_t handle)43 static inline int psa_key_handle_is_null(psa_key_handle_t handle)
44 {
45     return mbedtls_svc_key_id_is_null(handle);
46 }
47 
48 /** Open a handle to an existing persistent key.
49  *
50  * Open a handle to a persistent key. A key is persistent if it was created
51  * with a lifetime other than #PSA_KEY_LIFETIME_VOLATILE. A persistent key
52  * always has a nonzero key identifier, set with psa_set_key_id() when
53  * creating the key. Implementations may provide additional pre-provisioned
54  * keys that can be opened with psa_open_key(). Such keys have an application
55  * key identifier in the vendor range, as documented in the description of
56  * #psa_key_id_t.
57  *
58  * The application must eventually close the handle with psa_close_key() or
59  * psa_destroy_key() to release associated resources. If the application dies
60  * without calling one of these functions, the implementation should perform
61  * the equivalent of a call to psa_close_key().
62  *
63  * Some implementations permit an application to open the same key multiple
64  * times. If this is successful, each call to psa_open_key() will return a
65  * different key handle.
66  *
67  * \note This API is not part of the PSA Cryptography API Release 1.0.0
68  * specification. It was defined in the 1.0 Beta 3 version of the
69  * specification but was removed in the 1.0.0 released version. This API is
70  * kept for the time being to not break applications relying on it. It is not
71  * deprecated yet but will be in the near future.
72  *
73  * \note Applications that rely on opening a key multiple times will not be
74  * portable to implementations that only permit a single key handle to be
75  * opened. See also :ref:\`key-handles\`.
76  *
77  *
78  * \param key           The persistent identifier of the key.
79  * \param[out] handle   On success, a handle to the key.
80  *
81  * \retval #PSA_SUCCESS
82  *         Success. The application can now use the value of `*handle`
83  *         to access the key.
84  * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
85  *         The implementation does not have sufficient resources to open the
86  *         key. This can be due to reaching an implementation limit on the
87  *         number of open keys, the number of open key handles, or available
88  *         memory.
89  * \retval #PSA_ERROR_DOES_NOT_EXIST
90  *         There is no persistent key with key identifier \p key.
91  * \retval #PSA_ERROR_INVALID_ARGUMENT
92  *         \p key is not a valid persistent key identifier.
93  * \retval #PSA_ERROR_NOT_PERMITTED
94  *         The specified key exists, but the application does not have the
95  *         permission to access it. Note that this specification does not
96  *         define any way to create such a key, but it may be possible
97  *         through implementation-specific means.
98  * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
99  * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
100  * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription
101  * \retval #PSA_ERROR_DATA_INVALID \emptydescription
102  * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription
103  * \retval #PSA_ERROR_BAD_STATE
104  *         The library has not been previously initialized by psa_crypto_init().
105  *         It is implementation-dependent whether a failure to initialize
106  *         results in this error code.
107  */
108 psa_status_t psa_open_key(mbedtls_svc_key_id_t key,
109                           psa_key_handle_t *handle);
110 
111 /** Close a key handle.
112  *
113  * If the handle designates a volatile key, this will destroy the key material
114  * and free all associated resources, just like psa_destroy_key().
115  *
116  * If this is the last open handle to a persistent key, then closing the handle
117  * will free all resources associated with the key in volatile memory. The key
118  * data in persistent storage is not affected and can be opened again later
119  * with a call to psa_open_key().
120  *
121  * Closing the key handle makes the handle invalid, and the key handle
122  * must not be used again by the application.
123  *
124  * \note This API is not part of the PSA Cryptography API Release 1.0.0
125  * specification. It was defined in the 1.0 Beta 3 version of the
126  * specification but was removed in the 1.0.0 released version. This API is
127  * kept for the time being to not break applications relying on it. It is not
128  * deprecated yet but will be in the near future.
129  *
130  * \note If the key handle was used to set up an active
131  * :ref:\`multipart operation <multipart-operations>\`, then closing the
132  * key handle can cause the multipart operation to fail. Applications should
133  * maintain the key handle until after the multipart operation has finished.
134  *
135  * \param handle        The key handle to close.
136  *                      If this is \c 0, do nothing and return \c PSA_SUCCESS.
137  *
138  * \retval #PSA_SUCCESS
139  *         \p handle was a valid handle or \c 0. It is now closed.
140  * \retval #PSA_ERROR_INVALID_HANDLE
141  *         \p handle is not a valid handle nor \c 0.
142  * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
143  * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
144  * \retval #PSA_ERROR_BAD_STATE
145  *         The library has not been previously initialized by psa_crypto_init().
146  *         It is implementation-dependent whether a failure to initialize
147  *         results in this error code.
148  */
149 psa_status_t psa_close_key(psa_key_handle_t handle);
150 
151 #ifdef __cplusplus
152 }
153 #endif
154 
155 #endif /* PSA_CRYPTO_COMPAT_H */
156