1 /**
2  * \file helpers.h
3  *
4  * \brief   This file contains the prototypes of helper functions for the
5  *          purpose of testing.
6  */
7 
8 /*
9  *  Copyright The Mbed TLS Contributors
10  *  SPDX-License-Identifier: Apache-2.0
11  *
12  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
13  *  not use this file except in compliance with the License.
14  *  You may obtain a copy of the License at
15  *
16  *  http://www.apache.org/licenses/LICENSE-2.0
17  *
18  *  Unless required by applicable law or agreed to in writing, software
19  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
20  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
21  *  See the License for the specific language governing permissions and
22  *  limitations under the License.
23  */
24 
25 #ifndef TEST_HELPERS_H
26 #define TEST_HELPERS_H
27 
28 /* Most fields of publicly available structs are private and are wrapped with
29  * MBEDTLS_PRIVATE macro. This define allows tests to access the private fields
30  * directly (without using the MBEDTLS_PRIVATE wrapper). */
31 #define MBEDTLS_ALLOW_PRIVATE_ACCESS
32 
33 #include "mbedtls/build_info.h"
34 
35 #if defined(MBEDTLS_THREADING_C) && defined(MBEDTLS_THREADING_PTHREAD) && \
36     defined(MBEDTLS_TEST_HOOKS)
37 #define MBEDTLS_TEST_MUTEX_USAGE
38 #endif
39 
40 #include "mbedtls/platform.h"
41 
42 #include <stddef.h>
43 #include <stdint.h>
44 
45 #if defined(MBEDTLS_BIGNUM_C)
46 #include "mbedtls/bignum.h"
47 #endif
48 
49 /** The type of test case arguments that contain binary data. */
50 typedef struct data_tag
51 {
52     uint8_t *   x;
53     uint32_t    len;
54 } data_t;
55 
56 typedef enum
57 {
58     MBEDTLS_TEST_RESULT_SUCCESS = 0,
59     MBEDTLS_TEST_RESULT_FAILED,
60     MBEDTLS_TEST_RESULT_SKIPPED
61 } mbedtls_test_result_t;
62 
63 typedef struct
64 {
65     mbedtls_test_result_t result;
66     const char *test;
67     const char *filename;
68     int line_no;
69     unsigned long step;
70     char line1[76];
71     char line2[76];
72 #if defined(MBEDTLS_TEST_MUTEX_USAGE)
73     const char *mutex_usage_error;
74 #endif
75 }
76 mbedtls_test_info_t;
77 extern mbedtls_test_info_t mbedtls_test_info;
78 
79 int mbedtls_test_platform_setup( void );
80 void mbedtls_test_platform_teardown( void );
81 
82 /**
83  * \brief           Record the current test case as a failure.
84  *
85  *                  This function can be called directly however it is usually
86  *                  called via macros such as TEST_ASSERT, TEST_EQUAL,
87  *                  PSA_ASSERT, etc...
88  *
89  * \note            If the test case was already marked as failed, calling
90  *                  `mbedtls_test_fail( )` again will not overwrite any
91  *                  previous information about the failure.
92  *
93  * \param test      Description of the failure or assertion that failed. This
94  *                  MUST be a string literal.
95  * \param line_no   Line number where the failure originated.
96  * \param filename  Filename where the failure originated.
97  */
98 void mbedtls_test_fail( const char *test, int line_no, const char* filename );
99 
100 /**
101  * \brief           Record the current test case as skipped.
102  *
103  *                  This function can be called directly however it is usually
104  *                  called via the TEST_ASSUME macro.
105  *
106  * \param test      Description of the assumption that caused the test case to
107  *                  be skipped. This MUST be a string literal.
108  * \param line_no   Line number where the test case was skipped.
109  * \param filename  Filename where the test case was skipped.
110  */
111 void mbedtls_test_skip( const char *test, int line_no, const char* filename );
112 
113 /**
114  * \brief       Set the test step number for failure reports.
115  *
116  *              Call this function to display "step NNN" in addition to the
117  *              line number and file name if a test fails. Typically the "step
118  *              number" is the index of a for loop but it can be whatever you
119  *              want.
120  *
121  * \param step  The step number to report.
122  */
123 void mbedtls_test_set_step( unsigned long step );
124 
125 /**
126  * \brief       Reset mbedtls_test_info to a ready/starting state.
127  */
128 void mbedtls_test_info_reset( void );
129 
130 /**
131  * \brief           Record the current test case as a failure if two integers
132  *                  have a different value.
133  *
134  *                  This function is usually called via the macro
135  *                  #TEST_EQUAL.
136  *
137  * \param test      Description of the failure or assertion that failed. This
138  *                  MUST be a string literal. This normally has the form
139  *                  "EXPR1 == EXPR2" where EXPR1 has the value \p value1
140  *                  and EXPR2 has the value \p value2.
141  * \param line_no   Line number where the failure originated.
142  * \param filename  Filename where the failure originated.
143  * \param value1    The first value to compare.
144  * \param value2    The second value to compare.
145  *
146  * \return          \c 1 if the values are equal, otherwise \c 0.
147  */
148 int mbedtls_test_equal( const char *test, int line_no, const char* filename,
149                         unsigned long long value1, unsigned long long value2 );
150 
151 /**
152  * \brief           Record the current test case as a failure based
153  *                  on comparing two unsigned integers.
154  *
155  *                  This function is usually called via the macro
156  *                  #TEST_LE_U.
157  *
158  * \param test      Description of the failure or assertion that failed. This
159  *                  MUST be a string literal. This normally has the form
160  *                  "EXPR1 <= EXPR2" where EXPR1 has the value \p value1
161  *                  and EXPR2 has the value \p value2.
162  * \param line_no   Line number where the failure originated.
163  * \param filename  Filename where the failure originated.
164  * \param value1    The first value to compare.
165  * \param value2    The second value to compare.
166  *
167  * \return          \c 1 if \p value1 <= \p value2, otherwise \c 0.
168  */
169 int mbedtls_test_le_u( const char *test, int line_no, const char* filename,
170                        unsigned long long value1, unsigned long long value2 );
171 
172 /**
173  * \brief           Record the current test case as a failure based
174  *                  on comparing two signed integers.
175  *
176  *                  This function is usually called via the macro
177  *                  #TEST_LE_S.
178  *
179  * \param test      Description of the failure or assertion that failed. This
180  *                  MUST be a string literal. This normally has the form
181  *                  "EXPR1 <= EXPR2" where EXPR1 has the value \p value1
182  *                  and EXPR2 has the value \p value2.
183  * \param line_no   Line number where the failure originated.
184  * \param filename  Filename where the failure originated.
185  * \param value1    The first value to compare.
186  * \param value2    The second value to compare.
187  *
188  * \return          \c 1 if \p value1 <= \p value2, otherwise \c 0.
189  */
190 int mbedtls_test_le_s( const char *test, int line_no, const char* filename,
191                        long long value1, long long value2 );
192 
193 /**
194  * \brief          This function decodes the hexadecimal representation of
195  *                 data.
196  *
197  * \note           The output buffer can be the same as the input buffer. For
198  *                 any other overlapping of the input and output buffers, the
199  *                 behavior is undefined.
200  *
201  * \param obuf     Output buffer.
202  * \param obufmax  Size in number of bytes of \p obuf.
203  * \param ibuf     Input buffer.
204  * \param len      The number of unsigned char written in \p obuf. This must
205  *                 not be \c NULL.
206  *
207  * \return         \c 0 on success.
208  * \return         \c -1 if the output buffer is too small or the input string
209  *                 is not a valid hexadecimal representation.
210  */
211 int mbedtls_test_unhexify( unsigned char *obuf, size_t obufmax,
212                            const char *ibuf, size_t *len );
213 
214 void mbedtls_test_hexify( unsigned char *obuf,
215                           const unsigned char *ibuf,
216                           int len );
217 
218 /**
219  * Allocate and zeroize a buffer.
220  *
221  * If the size if zero, a pointer to a zeroized 1-byte buffer is returned.
222  *
223  * For convenience, dies if allocation fails.
224  */
225 unsigned char *mbedtls_test_zero_alloc( size_t len );
226 
227 /**
228  * Allocate and fill a buffer from hex data.
229  *
230  * The buffer is sized exactly as needed. This allows to detect buffer
231  * overruns (including overreads) when running the test suite under valgrind.
232  *
233  * If the size if zero, a pointer to a zeroized 1-byte buffer is returned.
234  *
235  * For convenience, dies if allocation fails.
236  */
237 unsigned char *mbedtls_test_unhexify_alloc( const char *ibuf, size_t *olen );
238 
239 int mbedtls_test_hexcmp( uint8_t * a, uint8_t * b,
240                          uint32_t a_len, uint32_t b_len );
241 
242 #if defined(MBEDTLS_PSA_CRYPTO_C) && defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
243 #include "test/fake_external_rng_for_test.h"
244 #endif
245 
246 #if defined(MBEDTLS_TEST_MUTEX_USAGE)
247 /** Permanently activate the mutex usage verification framework. See
248  * threading_helpers.c for information. */
249 void mbedtls_test_mutex_usage_init( void );
250 
251 /** Call this function after executing a test case to check for mutex usage
252  * errors. */
253 void mbedtls_test_mutex_usage_check( void );
254 #endif /* MBEDTLS_TEST_MUTEX_USAGE */
255 
256 #if defined(MBEDTLS_TEST_HOOKS)
257 /**
258  * \brief   Check that only a pure high-level error code is being combined with
259  *          a pure low-level error code as otherwise the resultant error code
260  *          would be corrupted.
261  *
262  * \note    Both high-level and low-level error codes cannot be greater than
263  *          zero however can be zero. If one error code is zero then the
264  *          other error code is returned even if both codes are zero.
265  *
266  * \note    If the check fails, fail the test currently being run.
267  */
268 void mbedtls_test_err_add_check( int high, int low,
269                                  const char *file, int line);
270 #endif
271 
272 #if defined(MBEDTLS_BIGNUM_C)
273 /** Allocate and populate a core MPI from a test case argument.
274  *
275  * This function allocates exactly as many limbs as necessary to fit
276  * the length of the input. In other words, it preserves leading zeros.
277  *
278  * The limb array is allocated with mbedtls_calloc() and must later be
279  * freed with mbedtls_free().
280  *
281  * \param[in,out] pX    The address where a pointer to the allocated limb
282  *                      array will be stored.
283  *                      \c *pX must be null on entry.
284  *                      On exit, \c *pX is null on error or if the number
285  *                      of limbs is 0.
286  * \param[out] plimbs   The address where the number of limbs will be stored.
287  * \param[in] input     The test argument to read.
288  *                      It is interpreted as a hexadecimal representation
289  *                      of a non-negative integer.
290  *
291  * \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
292  */
293 int mbedtls_test_read_mpi_core( mbedtls_mpi_uint **pX, size_t *plimbs,
294                                 const char *input );
295 
296 /** Read an MPI from a hexadecimal string.
297  *
298  * Like mbedtls_mpi_read_string(), but with tighter guarantees around
299  * edge cases.
300  *
301  * - This function guarantees that if \p s begins with '-' then the sign
302  *   bit of the result will be negative, even if the value is 0.
303  *   When this function encounters such a "negative 0", it
304  *   increments #mbedtls_test_case_uses_negative_0.
305  * - The size of the result is exactly the minimum number of limbs needed
306  *   to fit the digits in the input. In particular, this function constructs
307  *   a bignum with 0 limbs for an empty string, and a bignum with leading 0
308  *   limbs if the string has sufficiently many leading 0 digits.
309  *   This is important so that the "0 (null)" and "0 (1 limb)" and
310  *   "leading zeros" test cases do what they claim.
311  *
312  * \param[out] X        The MPI object to populate. It must be initialized.
313  * \param[in] s         The null-terminated hexadecimal string to read from.
314  *
315  * \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
316  */
317 int mbedtls_test_read_mpi( mbedtls_mpi *X, const char *s );
318 
319 /** Nonzero if the current test case had an input parsed with
320  * mbedtls_test_read_mpi() that is a negative 0 (`"-"`, `"-0"`, `"-00"`, etc.,
321  * constructing a result with the sign bit set to -1 and the value being
322  * all-limbs-0, which is not a valid representation in #mbedtls_mpi but is
323  * tested for robustness).
324  */
325 extern unsigned mbedtls_test_case_uses_negative_0;
326 #endif /* MBEDTLS_BIGNUM_C */
327 
328 #endif /* TEST_HELPERS_H */
329