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1 /*
2  * Helper functions for tests that use the PSA Crypto API.
3  */
4 /*
5  *  Copyright The Mbed TLS Contributors
6  *  SPDX-License-Identifier: Apache-2.0
7  *
8  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
9  *  not use this file except in compliance with the License.
10  *  You may obtain a copy of the License at
11  *
12  *  http://www.apache.org/licenses/LICENSE-2.0
13  *
14  *  Unless required by applicable law or agreed to in writing, software
15  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
16  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  *  See the License for the specific language governing permissions and
18  *  limitations under the License.
19  */
20 
21 #ifndef PSA_CRYPTO_HELPERS_H
22 #define PSA_CRYPTO_HELPERS_H
23 
24 #include "test/helpers.h"
25 
26 #if defined(MBEDTLS_PSA_CRYPTO_C)
27 #include "test/psa_helpers.h"
28 #include <psa/crypto.h>
29 #endif
30 
31 #if defined(MBEDTLS_USE_PSA_CRYPTO)
32 #include "mbedtls/psa_util.h"
33 #endif
34 
35 #if defined(MBEDTLS_PSA_CRYPTO_C)
36 /** Initialize the PSA Crypto subsystem. */
37 #define PSA_INIT() PSA_ASSERT(psa_crypto_init())
38 
39 /** Shut down the PSA Crypto subsystem and destroy persistent keys.
40  * Expect a clean shutdown, with no slots in use.
41  *
42  * If some key slots are still in use, record the test case as failed,
43  * but continue executing. This macro is suitable (and primarily intended)
44  * for use in the cleanup section of test functions.
45  *
46  * \note Persistent keys must be recorded with #TEST_USES_KEY_ID before
47  *       creating them.
48  */
49 #define PSA_DONE()                                                      \
50     do                                                                  \
51     {                                                                   \
52         mbedtls_test_fail_if_psa_leaking(__LINE__, __FILE__);           \
53         mbedtls_test_psa_purge_key_storage();                           \
54         mbedtls_psa_crypto_free();                                      \
55     }                                                                   \
56     while (0)
57 #else /*MBEDTLS_PSA_CRYPTO_C */
58 #define PSA_INIT() ((void) 0)
59 #define PSA_DONE() ((void) 0)
60 #endif /* MBEDTLS_PSA_CRYPTO_C */
61 
62 #if defined(MBEDTLS_PSA_CRYPTO_C)
63 
64 #if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
65 
66 /* Internal function for #TEST_USES_KEY_ID. Return 1 on success, 0 on failure. */
67 int mbedtls_test_uses_key_id(mbedtls_svc_key_id_t key_id);
68 
69 /** Destroy persistent keys recorded with #TEST_USES_KEY_ID.
70  */
71 void mbedtls_test_psa_purge_key_storage(void);
72 
73 /** Purge the in-memory cache of persistent keys recorded with
74  * #TEST_USES_KEY_ID.
75  *
76  * Call this function before calling PSA_DONE() if it's ok for
77  * persistent keys to still exist at this point.
78  */
79 void mbedtls_test_psa_purge_key_cache(void);
80 
81 /** \def TEST_USES_KEY_ID
82  *
83  * Call this macro in a test function before potentially creating a
84  * persistent key. Test functions that use this mechanism must call
85  * mbedtls_test_psa_purge_key_storage() in their cleanup code.
86  *
87  * This macro records a persistent key identifier as potentially used in the
88  * current test case. Recorded key identifiers will be cleaned up at the end
89  * of the test case, even on failure.
90  *
91  * This macro has no effect on volatile keys. Therefore, it is safe to call
92  * this macro in a test function that creates either volatile or persistent
93  * keys depending on the test data.
94  *
95  * This macro currently has no effect on special identifiers
96  * used to store implementation-specific files.
97  *
98  * Calling this macro multiple times on the same key identifier in the same
99  * test case has no effect.
100  *
101  * This macro can fail the test case if there isn't enough memory to
102  * record the key id.
103  *
104  * \param key_id    The PSA key identifier to record.
105  */
106 #define TEST_USES_KEY_ID(key_id)                      \
107     TEST_ASSERT(mbedtls_test_uses_key_id(key_id))
108 
109 #else /* MBEDTLS_PSA_CRYPTO_STORAGE_C */
110 
111 #define TEST_USES_KEY_ID(key_id) ((void) (key_id))
112 #define mbedtls_test_psa_purge_key_storage() ((void) 0)
113 #define mbedtls_test_psa_purge_key_cache() ((void) 0)
114 
115 #endif /* MBEDTLS_PSA_CRYPTO_STORAGE_C */
116 
117 /** Check for things that have not been cleaned up properly in the
118  * PSA subsystem.
119  *
120  * \return NULL if nothing has leaked.
121  * \return A string literal explaining what has not been cleaned up
122  *         if applicable.
123  */
124 const char *mbedtls_test_helper_is_psa_leaking(void);
125 
126 /** Check that no PSA Crypto key slots are in use.
127  *
128  * If any slots are in use, mark the current test as failed and jump to
129  * the exit label. This is equivalent to
130  * `TEST_ASSERT( ! mbedtls_test_helper_is_psa_leaking( ) )`
131  * but with a more informative message.
132  */
133 #define ASSERT_PSA_PRISTINE()                                           \
134     do                                                                  \
135     {                                                                   \
136         if (mbedtls_test_fail_if_psa_leaking(__LINE__, __FILE__))       \
137         goto exit;                                                      \
138     }                                                                   \
139     while (0)
140 
141 /** Shut down the PSA Crypto subsystem, allowing persistent keys to survive.
142  * Expect a clean shutdown, with no slots in use.
143  *
144  * If some key slots are still in use, record the test case as failed and
145  * jump to the `exit` label.
146  */
147 #define PSA_SESSION_DONE()                                             \
148     do                                                                  \
149     {                                                                   \
150         mbedtls_test_psa_purge_key_cache();                            \
151         ASSERT_PSA_PRISTINE();                                         \
152         mbedtls_psa_crypto_free();                                     \
153     }                                                                   \
154     while (0)
155 
156 
157 
158 #if defined(RECORD_PSA_STATUS_COVERAGE_LOG)
159 psa_status_t mbedtls_test_record_status(psa_status_t status,
160                                         const char *func,
161                                         const char *file, int line,
162                                         const char *expr);
163 
164 /** Return value logging wrapper macro.
165  *
166  * Evaluate \p expr. Write a line recording its value to the log file
167  * #STATUS_LOG_FILE_NAME and return the value. The line is a colon-separated
168  * list of fields:
169  * ```
170  * value of expr:string:__FILE__:__LINE__:expr
171  * ```
172  *
173  * The test code does not call this macro explicitly because that would
174  * be very invasive. Instead, we instrument the source code by defining
175  * a bunch of wrapper macros like
176  * ```
177  * #define psa_crypto_init() RECORD_STATUS("psa_crypto_init", psa_crypto_init())
178  * ```
179  * These macro definitions must be present in `instrument_record_status.h`
180  * when building the test suites.
181  *
182  * \param string    A string, normally a function name.
183  * \param expr      An expression to evaluate, normally a call of the function
184  *                  whose name is in \p string. This expression must return
185  *                  a value of type #psa_status_t.
186  * \return          The value of \p expr.
187  */
188 #define RECORD_STATUS(string, expr)                                   \
189     mbedtls_test_record_status((expr), string, __FILE__, __LINE__, #expr)
190 
191 #include "instrument_record_status.h"
192 
193 #endif /* defined(RECORD_PSA_STATUS_COVERAGE_LOG) */
194 
195 /** Return extended key usage policies.
196  *
197  * Do a key policy permission extension on key usage policies always involves
198  * permissions of other usage policies
199  * (like PSA_KEY_USAGE_SIGN_HASH involves PSA_KEY_USAGE_SIGN_MESSAGE).
200  */
201 psa_key_usage_t mbedtls_test_update_key_usage_flags(psa_key_usage_t usage_flags);
202 
203 /** Check that no PSA Crypto key slots are in use.
204  *
205  * If any slots are in use, mark the current test as failed.
206  *
207  * \return 0 if the key store is empty, 1 otherwise.
208  */
209 int mbedtls_test_fail_if_psa_leaking(int line_no, const char *filename);
210 
211 /** Skip a test case if the given key is a 192 bits AES key and the AES
212  *  implementation is at least partially provided by an accelerator or
213  *  alternative implementation.
214  *
215  *  Call this macro in a test case when a cryptographic operation that may
216  *  involve an AES operation returns a #PSA_ERROR_NOT_SUPPORTED error code.
217  *  The macro call will skip and not fail the test case in case the operation
218  *  involves a 192 bits AES key and the AES implementation is at least
219  *  partially provided by an accelerator or alternative implementation.
220  *
221  *  Hardware AES implementations not supporting 192 bits keys commonly exist.
222  *  Consequently, PSA test cases aim at not failing when an AES operation with
223  *  a 192 bits key performed by an alternative AES implementation returns
224  *  with the #PSA_ERROR_NOT_SUPPORTED error code. The purpose of this macro
225  *  is to facilitate this and make the test case code more readable.
226  *
227  *  \param key_type  Key type
228  *  \param key_bits  Key length in number of bits.
229  */
230 #if defined(MBEDTLS_AES_ALT) || \
231     defined(MBEDTLS_AES_SETKEY_ENC_ALT) || \
232     defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_AES)
233 #define MBEDTLS_TEST_HAVE_ALT_AES 1
234 #else
235 #define MBEDTLS_TEST_HAVE_ALT_AES 0
236 #endif
237 
238 #define MBEDTLS_TEST_PSA_SKIP_IF_ALT_AES_192(key_type, key_bits)        \
239     do                                                                    \
240     {                                                                     \
241         if ((MBEDTLS_TEST_HAVE_ALT_AES) &&                              \
242             ((key_type) == PSA_KEY_TYPE_AES) &&                       \
243             (key_bits == 192))                                         \
244         {                                                                 \
245             mbedtls_test_skip("AES-192 not supported", __LINE__, __FILE__);     \
246             goto exit;                                                    \
247         }                                                                 \
248     }                                                                     \
249     while (0)
250 
251 /** Skip a test case if a GCM operation with a nonce length different from
252  *  12 bytes fails and was performed by an accelerator or alternative
253  *  implementation.
254  *
255  *  Call this macro in a test case when an AEAD cryptography operation that
256  *  may involve the GCM mode returns with a #PSA_ERROR_NOT_SUPPORTED error
257  *  code. The macro call will skip and not fail the test case in case the
258  *  operation involves the GCM mode, a nonce with a length different from
259  *  12 bytes and the GCM mode implementation is an alternative one.
260  *
261  *  Hardware GCM implementations not supporting nonce lengths different from
262  *  12 bytes commonly exist, as supporting a non-12-byte nonce requires
263  *  additional computations involving the GHASH function.
264  *  Consequently, PSA test cases aim at not failing when an AEAD operation in
265  *  GCM mode with a nonce length different from 12 bytes is performed by an
266  *  alternative GCM implementation and returns with a #PSA_ERROR_NOT_SUPPORTED
267  *  error code. The purpose of this macro is to facilitate this check and make
268  *  the test case code more readable.
269  *
270  *  \param  alg             The AEAD algorithm.
271  *  \param  nonce_length    The nonce length in number of bytes.
272  */
273 #if defined(MBEDTLS_GCM_ALT) || \
274     defined(MBEDTLS_PSA_ACCEL_ALG_GCM)
275 #define MBEDTLS_TEST_HAVE_ALT_GCM  1
276 #else
277 #define MBEDTLS_TEST_HAVE_ALT_GCM  0
278 #endif
279 
280 #define MBEDTLS_TEST_PSA_SKIP_IF_ALT_GCM_NOT_12BYTES_NONCE(alg,           \
281                                                            nonce_length) \
282     do                                                                     \
283     {                                                                      \
284         if ((MBEDTLS_TEST_HAVE_ALT_GCM) &&                               \
285             (PSA_ALG_AEAD_WITH_SHORTENED_TAG((alg), 0) ==            \
286              PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0)) &&       \
287             ((nonce_length) != 12))                                   \
288         {                                                                  \
289             mbedtls_test_skip("GCM with non-12-byte IV is not supported", __LINE__, __FILE__); \
290             goto exit;                                                     \
291         }                                                                  \
292     }                                                                      \
293     while (0)
294 
295 #if !defined(MBEDTLS_MD_C)
296 #define PSA_INIT_IF_NO_MD() PSA_INIT()
297 #define PSA_DONE_IF_NO_MD() PSA_DONE()
298 #endif
299 #endif /* MBEDTLS_PSA_CRYPTO_C */
300 
301 #if defined(MBEDTLS_MD_C)
302 #define PSA_INIT_IF_NO_MD() ((void) 0)
303 #define PSA_DONE_IF_NO_MD() ((void) 0)
304 #endif
305 
306 /** \def USE_PSA_INIT
307  *
308  * Call this macro to initialize the PSA subsystem if #MBEDTLS_USE_PSA_CRYPTO
309  * or #MBEDTLS_SSL_PROTO_TLS1_3 (In contrast to TLS 1.2 implementation, the
310  * TLS 1.3 one uses PSA independently of the definition of
311  * #MBEDTLS_USE_PSA_CRYPTO) is enabled and do nothing otherwise. If the
312  * initialization fails, mark the test case as failed and jump to the \p exit
313  * label.
314  */
315 /** \def USE_PSA_DONE
316  *
317  * Call this macro at the end of a test case if you called #USE_PSA_INIT.
318  * This is like #PSA_DONE, except that it does nothing if
319  * #MBEDTLS_USE_PSA_CRYPTO is disabled.
320  */
321 #if defined(MBEDTLS_USE_PSA_CRYPTO) || defined(MBEDTLS_SSL_PROTO_TLS1_3)
322 #define USE_PSA_INIT() PSA_INIT()
323 #define USE_PSA_DONE() PSA_DONE()
324 #else /* MBEDTLS_USE_PSA_CRYPTO || MBEDTLS_SSL_PROTO_TLS1_3 */
325 /* Define empty macros so that we can use them in the preamble and teardown
326  * of every test function that uses PSA conditionally based on
327  * MBEDTLS_USE_PSA_CRYPTO. */
328 #define USE_PSA_INIT() ((void) 0)
329 #define USE_PSA_DONE() ((void) 0)
330 #endif /* !MBEDTLS_USE_PSA_CRYPTO && !MBEDTLS_SSL_PROTO_TLS1_3 */
331 
332 #endif /* PSA_CRYPTO_HELPERS_H */
333