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1/* BEGIN_HEADER */
2#include "mbedtls/bignum.h"
3#include "mbedtls/entropy.h"
4#include "constant_time_internal.h"
5#include "test/constant_flow.h"
6
7#if MBEDTLS_MPI_MAX_BITS > 792
8#define MPI_MAX_BITS_LARGER_THAN_792
9#endif
10
11/* Check the validity of the sign bit in an MPI object. Reject representations
12 * that are not supported by the rest of the library and indicate a bug when
13 * constructing the value. */
14static int sign_is_valid( const mbedtls_mpi *X )
15{
16    /* Only +1 and -1 are valid sign bits, not e.g. 0 */
17    if( X->s != 1 && X->s != -1 )
18        return( 0 );
19
20    /* The value 0 must be represented with the sign +1. A "negative zero"
21     * with s=-1 is an invalid representation. Forbid that. As an exception,
22     * we sometimes test the robustness of library functions when given
23     * a negative zero input. If a test case has a negative zero as input,
24     * we don't mind if the function has a negative zero output. */
25    if( ! mbedtls_test_case_uses_negative_0 &&
26        mbedtls_mpi_bitlen( X ) == 0 && X->s != 1 )
27    {
28        return( 0 );
29    }
30
31    return( 1 );
32}
33
34typedef struct mbedtls_test_mpi_random
35{
36    data_t *data;
37    size_t  pos;
38    size_t  chunk_len;
39} mbedtls_test_mpi_random;
40
41/*
42 * This function is called by the Miller-Rabin primality test each time it
43 * chooses a random witness. The witnesses (or non-witnesses as provided by the
44 * test) are stored in the data member of the state structure. Each number is in
45 * the format that mbedtls_mpi_read_string understands and is chunk_len long.
46 */
47int mbedtls_test_mpi_miller_rabin_determinizer( void* state,
48                                                unsigned char* buf,
49                                                size_t len )
50{
51    mbedtls_test_mpi_random *random = (mbedtls_test_mpi_random*) state;
52
53    if( random == NULL || random->data->x == NULL || buf == NULL )
54        return( -1 );
55
56    if( random->pos + random->chunk_len > random->data->len
57            || random->chunk_len > len )
58    {
59        return( -1 );
60    }
61
62    memset( buf, 0, len );
63
64    /* The witness is written to the end of the buffer, since the buffer is
65     * used as big endian, unsigned binary data in mbedtls_mpi_read_binary.
66     * Writing the witness to the start of the buffer would result in the
67     * buffer being 'witness 000...000', which would be treated as
68     * witness * 2^n for some n. */
69    memcpy( buf + len - random->chunk_len, &random->data->x[random->pos],
70            random->chunk_len );
71
72    random->pos += random->chunk_len;
73
74    return( 0 );
75}
76
77/* Random generator that is told how many bytes to return. */
78static int f_rng_bytes_left( void *state, unsigned char *buf, size_t len )
79{
80    size_t *bytes_left = state;
81    size_t i;
82    for( i = 0; i < len; i++ )
83    {
84        if( *bytes_left == 0 )
85            return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
86        buf[i] = *bytes_left & 0xff;
87        --( *bytes_left );
88    }
89    return( 0 );
90}
91
92/* Test whether bytes represents (in big-endian base 256) a number b that
93 * is significantly above a power of 2. That is, b must not have a long run
94 * of unset bits after the most significant bit.
95 *
96 * Let n be the bit-size of b, i.e. the integer such that 2^n <= b < 2^{n+1}.
97 * This function returns 1 if, when drawing a number between 0 and b,
98 * the probability that this number is at least 2^n is not negligible.
99 * This probability is (b - 2^n) / b and this function checks that this
100 * number is above some threshold A. The threshold value is heuristic and
101 * based on the needs of mpi_random_many().
102 */
103static int is_significantly_above_a_power_of_2( data_t *bytes )
104{
105    const uint8_t *p = bytes->x;
106    size_t len = bytes->len;
107    unsigned x;
108
109    /* Skip leading null bytes */
110    while( len > 0 && p[0] == 0 )
111    {
112        ++p;
113        --len;
114    }
115    /* 0 is not significantly above a power of 2 */
116    if( len == 0 )
117        return( 0 );
118    /* Extract the (up to) 2 most significant bytes */
119    if( len == 1 )
120        x = p[0];
121    else
122        x = ( p[0] << 8 ) | p[1];
123
124    /* Shift the most significant bit of x to position 8 and mask it out */
125    while( ( x & 0xfe00 ) != 0 )
126        x >>= 1;
127    x &= 0x00ff;
128
129    /* At this point, x = floor((b - 2^n) / 2^(n-8)). b is significantly above
130     * a power of 2 iff x is significantly above 0 compared to 2^8.
131     * Testing x >= 2^4 amounts to picking A = 1/16 in the function
132     * description above. */
133    return( x >= 0x10 );
134}
135
136/* END_HEADER */
137
138/* BEGIN_DEPENDENCIES
139 * depends_on:MBEDTLS_BIGNUM_C
140 * END_DEPENDENCIES
141 */
142
143/* BEGIN_CASE */
144void mpi_null(  )
145{
146    mbedtls_mpi X, Y, Z;
147
148    mbedtls_mpi_init( &X );
149    mbedtls_mpi_init( &Y );
150    mbedtls_mpi_init( &Z );
151
152    TEST_ASSERT( mbedtls_mpi_get_bit( &X, 42 ) == 0 );
153    TEST_ASSERT( mbedtls_mpi_lsb( &X ) == 0 );
154    TEST_ASSERT( mbedtls_mpi_bitlen( &X ) == 0 );
155    TEST_ASSERT( mbedtls_mpi_size( &X ) == 0 );
156
157exit:
158    mbedtls_mpi_free( &X );
159}
160/* END_CASE */
161
162/* BEGIN_CASE */
163void mpi_read_write_string( int radix_X, char * input_X, int radix_A,
164                            char * input_A, int output_size, int result_read,
165                            int result_write )
166{
167    mbedtls_mpi X;
168    char str[1000];
169    size_t len;
170
171    mbedtls_mpi_init( &X );
172
173    memset( str, '!', sizeof( str ) );
174
175    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == result_read );
176    if( result_read == 0 )
177    {
178        TEST_ASSERT( sign_is_valid( &X ) );
179        TEST_ASSERT( mbedtls_mpi_write_string( &X, radix_A, str, output_size, &len ) == result_write );
180        if( result_write == 0 )
181        {
182            TEST_ASSERT( strcasecmp( str, input_A ) == 0 );
183            TEST_ASSERT( str[len] == '!' );
184        }
185    }
186
187exit:
188    mbedtls_mpi_free( &X );
189}
190/* END_CASE */
191
192/* BEGIN_CASE */
193void mpi_read_binary( data_t * buf, char * input_A )
194{
195    mbedtls_mpi X;
196    char str[1000];
197    size_t len;
198
199    mbedtls_mpi_init( &X );
200
201
202    TEST_ASSERT( mbedtls_mpi_read_binary( &X, buf->x, buf->len ) == 0 );
203    TEST_ASSERT( sign_is_valid( &X ) );
204    TEST_ASSERT( mbedtls_mpi_write_string( &X, 16, str, sizeof( str ), &len ) == 0 );
205    TEST_ASSERT( strcmp( (char *) str, input_A ) == 0 );
206
207exit:
208    mbedtls_mpi_free( &X );
209}
210/* END_CASE */
211
212/* BEGIN_CASE */
213void mpi_read_binary_le( data_t * buf, char * input_A )
214{
215    mbedtls_mpi X;
216    char str[1000];
217    size_t len;
218
219    mbedtls_mpi_init( &X );
220
221
222    TEST_ASSERT( mbedtls_mpi_read_binary_le( &X, buf->x, buf->len ) == 0 );
223    TEST_ASSERT( sign_is_valid( &X ) );
224    TEST_ASSERT( mbedtls_mpi_write_string( &X, 16, str, sizeof( str ), &len ) == 0 );
225    TEST_ASSERT( strcmp( (char *) str, input_A ) == 0 );
226
227exit:
228    mbedtls_mpi_free( &X );
229}
230/* END_CASE */
231
232/* BEGIN_CASE */
233void mpi_write_binary( char * input_X, data_t * input_A,
234                       int output_size, int result )
235{
236    mbedtls_mpi X;
237    unsigned char buf[1000];
238    size_t buflen;
239
240    memset( buf, 0x00, 1000 );
241
242    mbedtls_mpi_init( &X );
243
244    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
245
246    buflen = mbedtls_mpi_size( &X );
247    if( buflen > (size_t) output_size )
248        buflen = (size_t) output_size;
249
250    TEST_ASSERT( mbedtls_mpi_write_binary( &X, buf, buflen ) == result );
251    if( result == 0)
252    {
253
254        TEST_ASSERT( mbedtls_test_hexcmp( buf, input_A->x,
255                                          buflen, input_A->len ) == 0 );
256    }
257
258exit:
259    mbedtls_mpi_free( &X );
260}
261/* END_CASE */
262
263/* BEGIN_CASE */
264void mpi_write_binary_le( char * input_X, data_t * input_A,
265                          int output_size, int result )
266{
267    mbedtls_mpi X;
268    unsigned char buf[1000];
269    size_t buflen;
270
271    memset( buf, 0x00, 1000 );
272
273    mbedtls_mpi_init( &X );
274
275    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
276
277    buflen = mbedtls_mpi_size( &X );
278    if( buflen > (size_t) output_size )
279        buflen = (size_t) output_size;
280
281    TEST_ASSERT( mbedtls_mpi_write_binary_le( &X, buf, buflen ) == result );
282    if( result == 0)
283    {
284
285        TEST_ASSERT( mbedtls_test_hexcmp( buf, input_A->x,
286                                          buflen, input_A->len ) == 0 );
287    }
288
289exit:
290    mbedtls_mpi_free( &X );
291}
292/* END_CASE */
293
294/* BEGIN_CASE depends_on:MBEDTLS_FS_IO */
295void mpi_read_file( char * input_file, data_t * input_A, int result )
296{
297    mbedtls_mpi X;
298    unsigned char buf[1000];
299    size_t buflen;
300    FILE *file;
301    int ret;
302
303    memset( buf, 0x00, 1000 );
304
305    mbedtls_mpi_init( &X );
306
307    file = fopen( input_file, "r" );
308    TEST_ASSERT( file != NULL );
309    ret = mbedtls_mpi_read_file( &X, 16, file );
310    fclose(file);
311    TEST_ASSERT( ret == result );
312
313    if( result == 0 )
314    {
315        TEST_ASSERT( sign_is_valid( &X ) );
316        buflen = mbedtls_mpi_size( &X );
317        TEST_ASSERT( mbedtls_mpi_write_binary( &X, buf, buflen ) == 0 );
318
319
320        TEST_ASSERT( mbedtls_test_hexcmp( buf, input_A->x,
321                                          buflen, input_A->len ) == 0 );
322    }
323
324exit:
325    mbedtls_mpi_free( &X );
326}
327/* END_CASE */
328
329/* BEGIN_CASE depends_on:MBEDTLS_FS_IO */
330void mpi_write_file( char * input_X, char * output_file )
331{
332    mbedtls_mpi X, Y;
333    FILE *file_out, *file_in;
334    int ret;
335
336    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
337
338    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
339
340    file_out = fopen( output_file, "w" );
341    TEST_ASSERT( file_out != NULL );
342    ret = mbedtls_mpi_write_file( NULL, &X, 16, file_out );
343    fclose(file_out);
344    TEST_ASSERT( ret == 0 );
345
346    file_in = fopen( output_file, "r" );
347    TEST_ASSERT( file_in != NULL );
348    ret = mbedtls_mpi_read_file( &Y, 16, file_in );
349    fclose(file_in);
350    TEST_ASSERT( ret == 0 );
351
352    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &Y ) == 0 );
353
354exit:
355    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
356}
357/* END_CASE */
358
359/* BEGIN_CASE */
360void mpi_get_bit( char * input_X, int pos, int val )
361{
362    mbedtls_mpi X;
363    mbedtls_mpi_init( &X );
364    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
365    TEST_ASSERT( mbedtls_mpi_get_bit( &X, pos ) == val );
366
367exit:
368    mbedtls_mpi_free( &X );
369}
370/* END_CASE */
371
372/* BEGIN_CASE */
373void mpi_set_bit( char * input_X, int pos, int val,
374                  char * output_Y, int result )
375{
376    mbedtls_mpi X, Y;
377    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
378
379    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
380    TEST_ASSERT( mbedtls_test_read_mpi( &Y, output_Y ) == 0 );
381    TEST_ASSERT( mbedtls_mpi_set_bit( &X, pos, val ) == result );
382
383    if( result == 0 )
384    {
385        TEST_ASSERT( sign_is_valid( &X ) );
386        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &Y ) == 0 );
387    }
388
389exit:
390    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
391}
392/* END_CASE */
393
394/* BEGIN_CASE */
395void mpi_lsb( char * input_X, int nr_bits )
396{
397    mbedtls_mpi X;
398    mbedtls_mpi_init( &X );
399
400    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
401    TEST_ASSERT( mbedtls_mpi_lsb( &X ) == (size_t) nr_bits );
402
403exit:
404    mbedtls_mpi_free( &X );
405}
406/* END_CASE */
407
408/* BEGIN_CASE */
409void mpi_bitlen( char * input_X, int nr_bits )
410{
411    mbedtls_mpi X;
412    mbedtls_mpi_init( &X );
413
414    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
415    TEST_ASSERT( mbedtls_mpi_bitlen( &X ) == (size_t) nr_bits );
416
417exit:
418    mbedtls_mpi_free( &X );
419}
420/* END_CASE */
421
422/* BEGIN_CASE */
423void mpi_gcd( char * input_X, char * input_Y,
424              char * input_A )
425{
426    mbedtls_mpi A, X, Y, Z;
427    mbedtls_mpi_init( &A ); mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z );
428
429    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
430    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
431    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
432    TEST_ASSERT( mbedtls_mpi_gcd( &Z, &X, &Y ) == 0 );
433    TEST_ASSERT( sign_is_valid( &Z ) );
434    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
435
436exit:
437    mbedtls_mpi_free( &A ); mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z );
438}
439/* END_CASE */
440
441/* BEGIN_CASE */
442void mpi_cmp_int( int input_X, int input_A, int result_CMP )
443{
444    mbedtls_mpi X;
445    mbedtls_mpi_init( &X  );
446
447    TEST_ASSERT( mbedtls_mpi_lset( &X, input_X ) == 0);
448    TEST_ASSERT( mbedtls_mpi_cmp_int( &X, input_A ) == result_CMP);
449
450exit:
451    mbedtls_mpi_free( &X );
452}
453/* END_CASE */
454
455/* BEGIN_CASE */
456void mpi_cmp_mpi( char * input_X, char * input_Y,
457                  int input_A )
458{
459    mbedtls_mpi X, Y;
460    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
461
462    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
463    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
464    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &Y ) == input_A );
465
466exit:
467    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
468}
469/* END_CASE */
470
471/* BEGIN_CASE */
472void mpi_lt_mpi_ct( int size_X, char * input_X,
473                    int size_Y, char * input_Y,
474                    int input_ret, int input_err )
475{
476    unsigned ret = -1;
477    unsigned input_uret = input_ret;
478    mbedtls_mpi X, Y;
479    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
480
481    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
482    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
483
484    TEST_ASSERT( mbedtls_mpi_grow( &X, size_X ) == 0 );
485    TEST_ASSERT( mbedtls_mpi_grow( &Y, size_Y ) == 0 );
486
487    TEST_ASSERT( mbedtls_mpi_lt_mpi_ct( &X, &Y, &ret ) == input_err );
488    if( input_err == 0 )
489        TEST_ASSERT( ret == input_uret );
490
491exit:
492    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
493}
494/* END_CASE */
495
496/* BEGIN_CASE */
497void mpi_cmp_abs( char * input_X, char * input_Y,
498                  int input_A )
499{
500    mbedtls_mpi X, Y;
501    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
502
503    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
504    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
505    TEST_ASSERT( mbedtls_mpi_cmp_abs( &X, &Y ) == input_A );
506
507exit:
508    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
509}
510/* END_CASE */
511
512/* BEGIN_CASE */
513void mpi_copy( char *src_hex, char *dst_hex )
514{
515    mbedtls_mpi src, dst, ref;
516    mbedtls_mpi_init( &src );
517    mbedtls_mpi_init( &dst );
518    mbedtls_mpi_init( &ref );
519
520    TEST_ASSERT( mbedtls_test_read_mpi( &src, src_hex ) == 0 );
521    TEST_ASSERT( mbedtls_test_read_mpi( &ref, dst_hex ) == 0 );
522
523    /* mbedtls_mpi_copy() */
524    TEST_ASSERT( mbedtls_test_read_mpi( &dst, dst_hex ) == 0 );
525    TEST_ASSERT( mbedtls_mpi_copy( &dst, &src ) == 0 );
526    TEST_ASSERT( sign_is_valid( &dst ) );
527    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &dst, &src ) == 0 );
528
529    /* mbedtls_mpi_safe_cond_assign(), assignment done */
530    mbedtls_mpi_free( &dst );
531    TEST_ASSERT( mbedtls_test_read_mpi( &dst, dst_hex ) == 0 );
532    TEST_ASSERT( mbedtls_mpi_safe_cond_assign( &dst, &src, 1 ) == 0 );
533    TEST_ASSERT( sign_is_valid( &dst ) );
534    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &dst, &src ) == 0 );
535
536    /* mbedtls_mpi_safe_cond_assign(), assignment not done */
537    mbedtls_mpi_free( &dst );
538    TEST_ASSERT( mbedtls_test_read_mpi( &dst, dst_hex ) == 0 );
539    TEST_ASSERT( mbedtls_mpi_safe_cond_assign( &dst, &src, 0 ) == 0 );
540    TEST_ASSERT( sign_is_valid( &dst ) );
541    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &dst, &ref ) == 0 );
542
543exit:
544    mbedtls_mpi_free( &src );
545    mbedtls_mpi_free( &dst );
546    mbedtls_mpi_free( &ref );
547}
548/* END_CASE */
549
550/* BEGIN_CASE */
551void mpi_copy_self( char *input_X )
552{
553    mbedtls_mpi X, A;
554    mbedtls_mpi_init( &A );
555    mbedtls_mpi_init( &X );
556
557    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
558    TEST_ASSERT( mbedtls_mpi_copy( &X, &X ) == 0 );
559
560    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_X ) == 0 );
561    TEST_ASSERT( sign_is_valid( &X ) );
562    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
563
564exit:
565    mbedtls_mpi_free( &A );
566    mbedtls_mpi_free( &X );
567}
568/* END_CASE */
569
570/* BEGIN_CASE */
571void mpi_swap( char *X_hex, char *Y_hex )
572{
573    mbedtls_mpi X, Y, X0, Y0;
574    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
575    mbedtls_mpi_init( &X0 ); mbedtls_mpi_init( &Y0 );
576
577    TEST_ASSERT( mbedtls_test_read_mpi( &X0, X_hex ) == 0 );
578    TEST_ASSERT( mbedtls_test_read_mpi( &Y0, Y_hex ) == 0 );
579
580    /* mbedtls_mpi_swap() */
581    TEST_ASSERT( mbedtls_test_read_mpi( &X, X_hex ) == 0 );
582    TEST_ASSERT( mbedtls_test_read_mpi( &Y, Y_hex ) == 0 );
583    mbedtls_mpi_swap( &X, &Y );
584    TEST_ASSERT( sign_is_valid( &X ) );
585    TEST_ASSERT( sign_is_valid( &Y ) );
586    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &Y0 ) == 0 );
587    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &X0 ) == 0 );
588
589    /* mbedtls_mpi_safe_cond_swap(), swap done */
590    mbedtls_mpi_free( &X );
591    mbedtls_mpi_free( &Y );
592    TEST_ASSERT( mbedtls_test_read_mpi( &X, X_hex ) == 0 );
593    TEST_ASSERT( mbedtls_test_read_mpi( &Y, Y_hex ) == 0 );
594    TEST_ASSERT( mbedtls_mpi_safe_cond_swap( &X, &Y, 1 ) == 0 );
595    TEST_ASSERT( sign_is_valid( &X ) );
596    TEST_ASSERT( sign_is_valid( &Y ) );
597    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &Y0 ) == 0 );
598    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &X0 ) == 0 );
599
600    /* mbedtls_mpi_safe_cond_swap(), swap not done */
601    mbedtls_mpi_free( &X );
602    mbedtls_mpi_free( &Y );
603    TEST_ASSERT( mbedtls_test_read_mpi( &X, X_hex ) == 0 );
604    TEST_ASSERT( mbedtls_test_read_mpi( &Y, Y_hex ) == 0 );
605    TEST_ASSERT( mbedtls_mpi_safe_cond_swap( &X, &Y, 0 ) == 0 );
606    TEST_ASSERT( sign_is_valid( &X ) );
607    TEST_ASSERT( sign_is_valid( &Y ) );
608    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &X0 ) == 0 );
609    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &Y0 ) == 0 );
610
611exit:
612    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y );
613    mbedtls_mpi_free( &X0 ); mbedtls_mpi_free( &Y0 );
614}
615/* END_CASE */
616
617/* BEGIN_CASE */
618void mpi_swap_self( char *X_hex )
619{
620    mbedtls_mpi X, X0;
621    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &X0 );
622
623    TEST_ASSERT( mbedtls_test_read_mpi( &X, X_hex ) == 0 );
624    TEST_ASSERT( mbedtls_test_read_mpi( &X0, X_hex ) == 0 );
625
626    mbedtls_mpi_swap( &X, &X );
627    TEST_ASSERT( sign_is_valid( &X ) );
628    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &X0 ) == 0 );
629
630exit:
631    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &X0 );
632}
633/* END_CASE */
634
635/* BEGIN_CASE */
636void mpi_shrink( int before, int used, int min, int after )
637{
638    mbedtls_mpi X;
639    mbedtls_mpi_init( &X );
640
641    TEST_ASSERT( mbedtls_mpi_grow( &X, before ) == 0 );
642    if( used > 0 )
643    {
644        size_t used_bit_count = used * 8 * sizeof( mbedtls_mpi_uint );
645        TEST_ASSERT( mbedtls_mpi_set_bit( &X, used_bit_count - 1, 1 ) == 0 );
646    }
647    TEST_EQUAL( X.n, (size_t) before );
648    TEST_ASSERT( mbedtls_mpi_shrink( &X, min ) == 0 );
649    TEST_EQUAL( X.n, (size_t) after );
650
651exit:
652    mbedtls_mpi_free( &X );
653}
654/* END_CASE */
655
656/* BEGIN_CASE */
657void mpi_add_mpi( char * input_X, char * input_Y,
658                  char * input_A )
659{
660    mbedtls_mpi X, Y, Z, A;
661    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
662
663    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
664    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
665    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
666    TEST_ASSERT( mbedtls_mpi_add_mpi( &Z, &X, &Y ) == 0 );
667    TEST_ASSERT( sign_is_valid( &Z ) );
668    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
669
670    /* result == first operand */
671    TEST_ASSERT( mbedtls_mpi_add_mpi( &X, &X, &Y ) == 0 );
672    TEST_ASSERT( sign_is_valid( &X ) );
673    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
674    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
675
676    /* result == second operand */
677    TEST_ASSERT( mbedtls_mpi_add_mpi( &Y, &X, &Y ) == 0 );
678    TEST_ASSERT( sign_is_valid( &Y ) );
679    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
680
681exit:
682    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
683}
684/* END_CASE */
685
686/* BEGIN_CASE */
687void mpi_add_mpi_inplace( char * input_X, char * input_A )
688{
689    mbedtls_mpi X, A;
690    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &A );
691
692    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
693
694    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
695    TEST_ASSERT( mbedtls_mpi_sub_abs( &X, &X, &X ) == 0 );
696    TEST_ASSERT( mbedtls_mpi_cmp_int( &X, 0 ) == 0 );
697    TEST_ASSERT( sign_is_valid( &X ) );
698
699    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
700    TEST_ASSERT( mbedtls_mpi_add_abs( &X, &X, &X ) == 0 );
701    TEST_ASSERT( sign_is_valid( &X ) );
702    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
703
704    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
705    TEST_ASSERT( mbedtls_mpi_add_mpi( &X, &X, &X ) == 0 );
706    TEST_ASSERT( sign_is_valid( &X ) );
707    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
708
709exit:
710    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &A );
711}
712/* END_CASE */
713
714
715/* BEGIN_CASE */
716void mpi_add_abs( char * input_X, char * input_Y,
717                  char * input_A )
718{
719    mbedtls_mpi X, Y, Z, A;
720    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
721
722    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
723    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
724    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
725    TEST_ASSERT( mbedtls_mpi_add_abs( &Z, &X, &Y ) == 0 );
726    TEST_ASSERT( sign_is_valid( &Z ) );
727    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
728
729    /* result == first operand */
730    TEST_ASSERT( mbedtls_mpi_add_abs( &X, &X, &Y ) == 0 );
731    TEST_ASSERT( sign_is_valid( &X ) );
732    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
733    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
734
735    /* result == second operand */
736    TEST_ASSERT( mbedtls_mpi_add_abs( &Y, &X, &Y ) == 0 );
737    TEST_ASSERT( sign_is_valid( &Y ) );
738    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
739
740exit:
741    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
742}
743/* END_CASE */
744
745/* BEGIN_CASE */
746void mpi_add_int( char * input_X, int input_Y,
747                  char * input_A )
748{
749    mbedtls_mpi X, Z, A;
750    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
751
752    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
753    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
754    TEST_ASSERT( mbedtls_mpi_add_int( &Z, &X, input_Y ) == 0 );
755    TEST_ASSERT( sign_is_valid( &Z ) );
756    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
757
758exit:
759    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
760}
761/* END_CASE */
762
763/* BEGIN_CASE */
764void mpi_sub_mpi( char * input_X, char * input_Y,
765                  char * input_A )
766{
767    mbedtls_mpi X, Y, Z, A;
768    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
769
770    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
771    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
772    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
773    TEST_ASSERT( mbedtls_mpi_sub_mpi( &Z, &X, &Y ) == 0 );
774    TEST_ASSERT( sign_is_valid( &Z ) );
775    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
776
777    /* result == first operand */
778    TEST_ASSERT( mbedtls_mpi_sub_mpi( &X, &X, &Y ) == 0 );
779    TEST_ASSERT( sign_is_valid( &X ) );
780    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
781    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
782
783    /* result == second operand */
784    TEST_ASSERT( mbedtls_mpi_sub_mpi( &Y, &X, &Y ) == 0 );
785    TEST_ASSERT( sign_is_valid( &Y ) );
786    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
787
788exit:
789    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
790}
791/* END_CASE */
792
793/* BEGIN_CASE */
794void mpi_sub_abs( char * input_X, char * input_Y,
795                  char * input_A, int sub_result )
796{
797    mbedtls_mpi X, Y, Z, A;
798    int res;
799    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
800
801    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
802    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
803    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
804
805    res = mbedtls_mpi_sub_abs( &Z, &X, &Y );
806    TEST_ASSERT( res == sub_result );
807    TEST_ASSERT( sign_is_valid( &Z ) );
808    if( res == 0 )
809        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
810
811    /* result == first operand */
812    TEST_ASSERT( mbedtls_mpi_sub_abs( &X, &X, &Y ) == sub_result );
813    TEST_ASSERT( sign_is_valid( &X ) );
814    if( sub_result == 0 )
815        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
816    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
817
818    /* result == second operand */
819    TEST_ASSERT( mbedtls_mpi_sub_abs( &Y, &X, &Y ) == sub_result );
820    TEST_ASSERT( sign_is_valid( &Y ) );
821    if( sub_result == 0 )
822        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
823
824exit:
825    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
826}
827/* END_CASE */
828
829/* BEGIN_CASE */
830void mpi_sub_int( char * input_X, int input_Y,
831                  char * input_A )
832{
833    mbedtls_mpi X, Z, A;
834    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
835
836    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
837    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
838    TEST_ASSERT( mbedtls_mpi_sub_int( &Z, &X, input_Y ) == 0 );
839    TEST_ASSERT( sign_is_valid( &Z ) );
840    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
841
842exit:
843    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
844}
845/* END_CASE */
846
847/* BEGIN_CASE */
848void mpi_mul_mpi( char * input_X, char * input_Y,
849                  char * input_A )
850{
851    mbedtls_mpi X, Y, Z, A;
852    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
853
854    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
855    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
856    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
857    TEST_ASSERT( mbedtls_mpi_mul_mpi( &Z, &X, &Y ) == 0 );
858    TEST_ASSERT( sign_is_valid( &Z ) );
859    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
860
861exit:
862    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
863}
864/* END_CASE */
865
866/* BEGIN_CASE */
867void mpi_mul_int( char * input_X, int input_Y,
868                  char * input_A, char * result_comparison )
869{
870    mbedtls_mpi X, Z, A;
871    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
872
873    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
874    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
875    TEST_ASSERT( mbedtls_mpi_mul_int( &Z, &X, input_Y ) == 0 );
876    TEST_ASSERT( sign_is_valid( &Z ) );
877    if( strcmp( result_comparison, "==" ) == 0 )
878        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
879    else if( strcmp( result_comparison, "!=" ) == 0 )
880        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) != 0 );
881    else
882        TEST_ASSERT( "unknown operator" == 0 );
883
884exit:
885    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
886}
887/* END_CASE */
888
889/* BEGIN_CASE */
890void mpi_div_mpi( char * input_X, char * input_Y,
891                  char * input_A, char * input_B,
892                  int div_result )
893{
894    mbedtls_mpi X, Y, Q, R, A, B;
895    int res;
896    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &R );
897    mbedtls_mpi_init( &A ); mbedtls_mpi_init( &B );
898
899    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
900    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
901    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
902    TEST_ASSERT( mbedtls_test_read_mpi( &B, input_B ) == 0 );
903    res = mbedtls_mpi_div_mpi( &Q, &R, &X, &Y );
904    TEST_ASSERT( res == div_result );
905    if( res == 0 )
906    {
907        TEST_ASSERT( sign_is_valid( &Q ) );
908        TEST_ASSERT( sign_is_valid( &R ) );
909        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Q, &A ) == 0 );
910        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &R, &B ) == 0 );
911    }
912
913exit:
914    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Q ); mbedtls_mpi_free( &R );
915    mbedtls_mpi_free( &A ); mbedtls_mpi_free( &B );
916}
917/* END_CASE */
918
919/* BEGIN_CASE */
920void mpi_div_int( char * input_X, int input_Y,
921                  char * input_A, char * input_B,
922                  int div_result )
923{
924    mbedtls_mpi X, Q, R, A, B;
925    int res;
926    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &R ); mbedtls_mpi_init( &A );
927    mbedtls_mpi_init( &B );
928
929    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
930    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
931    TEST_ASSERT( mbedtls_test_read_mpi( &B, input_B ) == 0 );
932    res = mbedtls_mpi_div_int( &Q, &R, &X, input_Y );
933    TEST_ASSERT( res == div_result );
934    if( res == 0 )
935    {
936        TEST_ASSERT( sign_is_valid( &Q ) );
937        TEST_ASSERT( sign_is_valid( &R ) );
938        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Q, &A ) == 0 );
939        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &R, &B ) == 0 );
940    }
941
942exit:
943    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Q ); mbedtls_mpi_free( &R ); mbedtls_mpi_free( &A );
944    mbedtls_mpi_free( &B );
945}
946/* END_CASE */
947
948/* BEGIN_CASE */
949void mpi_mod_mpi( char * input_X, char * input_Y,
950                  char * input_A, int div_result )
951{
952    mbedtls_mpi X, Y, A;
953    int res;
954    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &A );
955
956    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
957    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
958    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
959    res = mbedtls_mpi_mod_mpi( &X, &X, &Y );
960    TEST_ASSERT( res == div_result );
961    if( res == 0 )
962    {
963        TEST_ASSERT( sign_is_valid( &X ) );
964        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
965    }
966
967exit:
968    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &A );
969}
970/* END_CASE */
971
972/* BEGIN_CASE */
973void mpi_mod_int( char * input_X, char * input_Y,
974                  char * input_A, int mod_result )
975{
976    mbedtls_mpi X;
977    mbedtls_mpi Y;
978    mbedtls_mpi A;
979    int res;
980    mbedtls_mpi_uint r;
981
982    mbedtls_mpi_init( &X );
983    mbedtls_mpi_init( &Y );
984    mbedtls_mpi_init( &A );
985
986    /* We use MPIs to read Y and A since the test framework limits us to
987     * ints, so we can't have 64-bit values */
988    TEST_EQUAL( mbedtls_test_read_mpi( &X, input_X ), 0 );
989    TEST_EQUAL( mbedtls_test_read_mpi( &Y, input_Y ), 0 );
990    TEST_EQUAL( mbedtls_test_read_mpi( &A, input_A ), 0 );
991
992    TEST_EQUAL( Y.n, 1 );
993    TEST_EQUAL( A.n, 1 );
994
995    /* Convert the MPIs for Y and A to (signed) mbedtls_mpi_sints */
996
997    /* Since we're converting sign+magnitude to two's complement, we lose one
998     * bit of value in the output. This means there are some values we can't
999     * represent, e.g. (hex) -A0000000 on 32-bit systems. These are technically
1000     * invalid test cases, so could be considered "won't happen", but they are
1001     * easy to test for, and this helps guard against human error. */
1002
1003    mbedtls_mpi_sint y = (mbedtls_mpi_sint) Y.p[0];
1004    TEST_ASSERT( y >= 0 );      /* If y < 0 here, we can't make negative y */
1005    if( Y.s == -1 )
1006        y = -y;
1007
1008    mbedtls_mpi_sint a = (mbedtls_mpi_sint) A.p[0];
1009    TEST_ASSERT( a >= 0 );      /* Same goes for a */
1010    if( A.s == -1 )
1011        a = -a;
1012
1013    res = mbedtls_mpi_mod_int( &r, &X, y );
1014    TEST_EQUAL( res, mod_result );
1015    if( res == 0 )
1016    {
1017        TEST_EQUAL( r, a );
1018    }
1019
1020exit:
1021    mbedtls_mpi_free( &X );
1022    mbedtls_mpi_free( &Y );
1023    mbedtls_mpi_free( &A );
1024}
1025/* END_CASE */
1026
1027/* BEGIN_CASE */
1028void mpi_exp_mod( char * input_A, char * input_E,
1029                  char * input_N, char * input_X,
1030                  int exp_result )
1031{
1032    mbedtls_mpi A, E, N, RR, Z, X;
1033    int res;
1034    mbedtls_mpi_init( &A  ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &N );
1035    mbedtls_mpi_init( &RR ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &X );
1036
1037    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
1038    TEST_ASSERT( mbedtls_test_read_mpi( &E, input_E ) == 0 );
1039    TEST_ASSERT( mbedtls_test_read_mpi( &N, input_N ) == 0 );
1040    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
1041
1042    res = mbedtls_mpi_exp_mod( &Z, &A, &E, &N, NULL );
1043    TEST_ASSERT( res == exp_result );
1044    if( res == 0 )
1045    {
1046        TEST_ASSERT( sign_is_valid( &Z ) );
1047        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &X ) == 0 );
1048    }
1049
1050    /* Now test again with the speed-up parameter supplied as an output. */
1051    res = mbedtls_mpi_exp_mod( &Z, &A, &E, &N, &RR );
1052    TEST_ASSERT( res == exp_result );
1053    if( res == 0 )
1054    {
1055        TEST_ASSERT( sign_is_valid( &Z ) );
1056        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &X ) == 0 );
1057    }
1058
1059    /* Now test again with the speed-up parameter supplied in calculated form. */
1060    res = mbedtls_mpi_exp_mod( &Z, &A, &E, &N, &RR );
1061    TEST_ASSERT( res == exp_result );
1062    if( res == 0 )
1063    {
1064        TEST_ASSERT( sign_is_valid( &Z ) );
1065        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &X ) == 0 );
1066    }
1067
1068exit:
1069    mbedtls_mpi_free( &A  ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &N );
1070    mbedtls_mpi_free( &RR ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &X );
1071}
1072/* END_CASE */
1073
1074/* BEGIN_CASE */
1075void mpi_exp_mod_size( int A_bytes, int E_bytes, int N_bytes,
1076                       char * input_RR, int exp_result )
1077{
1078    mbedtls_mpi A, E, N, RR, Z;
1079    mbedtls_mpi_init( &A  ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &N );
1080    mbedtls_mpi_init( &RR ); mbedtls_mpi_init( &Z );
1081
1082    /* Set A to 2^(A_bytes - 1) + 1 */
1083    TEST_ASSERT( mbedtls_mpi_lset( &A, 1 ) == 0 );
1084    TEST_ASSERT( mbedtls_mpi_shift_l( &A, ( A_bytes * 8 ) - 1 ) == 0 );
1085    TEST_ASSERT( mbedtls_mpi_set_bit( &A, 0, 1 ) == 0 );
1086
1087    /* Set E to 2^(E_bytes - 1) + 1 */
1088    TEST_ASSERT( mbedtls_mpi_lset( &E, 1 ) == 0 );
1089    TEST_ASSERT( mbedtls_mpi_shift_l( &E, ( E_bytes * 8 ) - 1 ) == 0 );
1090    TEST_ASSERT( mbedtls_mpi_set_bit( &E, 0, 1 ) == 0 );
1091
1092    /* Set N to 2^(N_bytes - 1) + 1 */
1093    TEST_ASSERT( mbedtls_mpi_lset( &N, 1 ) == 0 );
1094    TEST_ASSERT( mbedtls_mpi_shift_l( &N, ( N_bytes * 8 ) - 1 ) == 0 );
1095    TEST_ASSERT( mbedtls_mpi_set_bit( &N, 0, 1 ) == 0 );
1096
1097    if( strlen( input_RR ) )
1098        TEST_ASSERT( mbedtls_test_read_mpi( &RR, input_RR ) == 0 );
1099
1100    TEST_ASSERT( mbedtls_mpi_exp_mod( &Z, &A, &E, &N, &RR ) == exp_result );
1101
1102exit:
1103    mbedtls_mpi_free( &A  ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &N );
1104    mbedtls_mpi_free( &RR ); mbedtls_mpi_free( &Z );
1105}
1106/* END_CASE */
1107
1108/* BEGIN_CASE */
1109void mpi_inv_mod( char * input_X, char * input_Y,
1110                  char * input_A, int div_result )
1111{
1112    mbedtls_mpi X, Y, Z, A;
1113    int res;
1114    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
1115
1116    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
1117    TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 );
1118    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
1119    res = mbedtls_mpi_inv_mod( &Z, &X, &Y );
1120    TEST_ASSERT( res == div_result );
1121    if( res == 0 )
1122    {
1123        TEST_ASSERT( sign_is_valid( &Z ) );
1124        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
1125    }
1126
1127exit:
1128    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
1129}
1130/* END_CASE */
1131
1132/* BEGIN_CASE depends_on:MBEDTLS_GENPRIME */
1133void mpi_is_prime( char * input_X, int div_result )
1134{
1135    mbedtls_mpi X;
1136    int res;
1137    mbedtls_mpi_init( &X );
1138
1139    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
1140    res = mbedtls_mpi_is_prime_ext( &X, 40, mbedtls_test_rnd_std_rand, NULL );
1141    TEST_ASSERT( res == div_result );
1142
1143exit:
1144    mbedtls_mpi_free( &X );
1145}
1146/* END_CASE */
1147
1148/* BEGIN_CASE depends_on:MBEDTLS_GENPRIME */
1149void mpi_is_prime_det( data_t * input_X, data_t * witnesses,
1150                       int chunk_len, int rounds )
1151{
1152    mbedtls_mpi X;
1153    int res;
1154    mbedtls_test_mpi_random rand;
1155
1156    mbedtls_mpi_init( &X );
1157    rand.data = witnesses;
1158    rand.pos = 0;
1159    rand.chunk_len = chunk_len;
1160
1161    TEST_ASSERT( mbedtls_mpi_read_binary( &X, input_X->x, input_X->len ) == 0 );
1162    res = mbedtls_mpi_is_prime_ext( &X, rounds - 1,
1163                                    mbedtls_test_mpi_miller_rabin_determinizer,
1164                                    &rand );
1165    TEST_ASSERT( res == 0 );
1166
1167    rand.data = witnesses;
1168    rand.pos = 0;
1169    rand.chunk_len = chunk_len;
1170
1171    res = mbedtls_mpi_is_prime_ext( &X, rounds,
1172                                    mbedtls_test_mpi_miller_rabin_determinizer,
1173                                    &rand );
1174    TEST_ASSERT( res == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
1175
1176exit:
1177    mbedtls_mpi_free( &X );
1178}
1179/* END_CASE */
1180
1181/* BEGIN_CASE depends_on:MBEDTLS_GENPRIME */
1182void mpi_gen_prime( int bits, int flags, int ref_ret )
1183{
1184    mbedtls_mpi X;
1185    int my_ret;
1186
1187    mbedtls_mpi_init( &X );
1188
1189    my_ret = mbedtls_mpi_gen_prime( &X, bits, flags,
1190                                    mbedtls_test_rnd_std_rand, NULL );
1191    TEST_ASSERT( my_ret == ref_ret );
1192
1193    if( ref_ret == 0 )
1194    {
1195        size_t actual_bits = mbedtls_mpi_bitlen( &X );
1196
1197        TEST_ASSERT( actual_bits >= (size_t) bits );
1198        TEST_ASSERT( actual_bits <= (size_t) bits + 1 );
1199        TEST_ASSERT( sign_is_valid( &X ) );
1200
1201        TEST_ASSERT( mbedtls_mpi_is_prime_ext( &X, 40,
1202                                               mbedtls_test_rnd_std_rand,
1203                                               NULL ) == 0 );
1204        if( flags & MBEDTLS_MPI_GEN_PRIME_FLAG_DH )
1205        {
1206            /* X = ( X - 1 ) / 2 */
1207            TEST_ASSERT( mbedtls_mpi_shift_r( &X, 1 ) == 0 );
1208            TEST_ASSERT( mbedtls_mpi_is_prime_ext( &X, 40,
1209                                                   mbedtls_test_rnd_std_rand,
1210                                                   NULL ) == 0 );
1211        }
1212    }
1213
1214exit:
1215    mbedtls_mpi_free( &X );
1216}
1217/* END_CASE */
1218
1219/* BEGIN_CASE */
1220void mpi_shift_l( char * input_X, int shift_X,
1221                  char * input_A )
1222{
1223    mbedtls_mpi X, A;
1224    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &A );
1225
1226    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
1227    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
1228    TEST_ASSERT( mbedtls_mpi_shift_l( &X, shift_X ) == 0 );
1229    TEST_ASSERT( sign_is_valid( &X ) );
1230    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
1231
1232exit:
1233    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &A );
1234}
1235/* END_CASE */
1236
1237/* BEGIN_CASE */
1238void mpi_shift_r( char * input_X, int shift_X,
1239                  char * input_A )
1240{
1241    mbedtls_mpi X, A;
1242    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &A );
1243
1244    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
1245    TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 );
1246    TEST_ASSERT( mbedtls_mpi_shift_r( &X, shift_X ) == 0 );
1247    TEST_ASSERT( sign_is_valid( &X ) );
1248    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
1249
1250exit:
1251    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &A );
1252}
1253/* END_CASE */
1254
1255/* BEGIN_CASE */
1256void mpi_fill_random( int wanted_bytes, int rng_bytes,
1257                      int before, int expected_ret )
1258{
1259    mbedtls_mpi X;
1260    int ret;
1261    size_t bytes_left = rng_bytes;
1262    mbedtls_mpi_init( &X );
1263
1264    if( before != 0 )
1265    {
1266        /* Set X to sign(before) * 2^(|before|-1) */
1267        TEST_ASSERT( mbedtls_mpi_lset( &X, before > 0 ? 1 : -1 ) == 0 );
1268        if( before < 0 )
1269            before = - before;
1270        TEST_ASSERT( mbedtls_mpi_shift_l( &X, before - 1 ) == 0 );
1271    }
1272
1273    ret = mbedtls_mpi_fill_random( &X, wanted_bytes,
1274                                   f_rng_bytes_left, &bytes_left );
1275    TEST_ASSERT( ret == expected_ret );
1276
1277    if( expected_ret == 0 )
1278    {
1279        /* mbedtls_mpi_fill_random is documented to use bytes from the RNG
1280         * as a big-endian representation of the number. We know when
1281         * our RNG function returns null bytes, so we know how many
1282         * leading zero bytes the number has. */
1283        size_t leading_zeros = 0;
1284        if( wanted_bytes > 0 && rng_bytes % 256 == 0 )
1285            leading_zeros = 1;
1286        TEST_ASSERT( mbedtls_mpi_size( &X ) + leading_zeros ==
1287                     (size_t) wanted_bytes );
1288        TEST_ASSERT( (int) bytes_left == rng_bytes - wanted_bytes );
1289        TEST_ASSERT( sign_is_valid( &X ) );
1290    }
1291
1292exit:
1293    mbedtls_mpi_free( &X );
1294}
1295/* END_CASE */
1296
1297/* BEGIN_CASE */
1298void mpi_random_many( int min, data_t *bound_bytes, int iterations )
1299{
1300    /* Generate numbers in the range 1..bound-1. Do it iterations times.
1301     * This function assumes that the value of bound is at least 2 and
1302     * that iterations is large enough that a one-in-2^iterations chance
1303     * effectively never occurs.
1304     */
1305
1306    mbedtls_mpi upper_bound;
1307    size_t n_bits;
1308    mbedtls_mpi result;
1309    size_t b;
1310    /* If upper_bound is small, stats[b] is the number of times the value b
1311     * has been generated. Otherwise stats[b] is the number of times a
1312     * value with bit b set has been generated. */
1313    size_t *stats = NULL;
1314    size_t stats_len;
1315    int full_stats;
1316    size_t i;
1317
1318    mbedtls_mpi_init( &upper_bound );
1319    mbedtls_mpi_init( &result );
1320
1321    TEST_EQUAL( 0, mbedtls_mpi_read_binary( &upper_bound,
1322                                            bound_bytes->x, bound_bytes->len ) );
1323    n_bits = mbedtls_mpi_bitlen( &upper_bound );
1324    /* Consider a bound "small" if it's less than 2^5. This value is chosen
1325     * to be small enough that the probability of missing one value is
1326     * negligible given the number of iterations. It must be less than
1327     * 256 because some of the code below assumes that "small" values
1328     * fit in a byte. */
1329    if( n_bits <= 5 )
1330    {
1331        full_stats = 1;
1332        stats_len = bound_bytes->x[bound_bytes->len - 1];
1333    }
1334    else
1335    {
1336        full_stats = 0;
1337        stats_len = n_bits;
1338    }
1339    ASSERT_ALLOC( stats, stats_len );
1340
1341    for( i = 0; i < (size_t) iterations; i++ )
1342    {
1343        mbedtls_test_set_step( i );
1344        TEST_EQUAL( 0, mbedtls_mpi_random( &result, min, &upper_bound,
1345                                           mbedtls_test_rnd_std_rand, NULL ) );
1346
1347        TEST_ASSERT( sign_is_valid( &result ) );
1348        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &result, &upper_bound ) < 0 );
1349        TEST_ASSERT( mbedtls_mpi_cmp_int( &result, min ) >= 0 );
1350        if( full_stats )
1351        {
1352            uint8_t value;
1353            TEST_EQUAL( 0, mbedtls_mpi_write_binary( &result, &value, 1 ) );
1354            TEST_ASSERT( value < stats_len );
1355            ++stats[value];
1356        }
1357        else
1358        {
1359            for( b = 0; b < n_bits; b++ )
1360                stats[b] += mbedtls_mpi_get_bit( &result, b );
1361        }
1362    }
1363
1364    if( full_stats )
1365    {
1366        for( b = min; b < stats_len; b++ )
1367        {
1368            mbedtls_test_set_step( 1000000 + b );
1369            /* Assert that each value has been reached at least once.
1370             * This is almost guaranteed if the iteration count is large
1371             * enough. This is a very crude way of checking the distribution.
1372             */
1373            TEST_ASSERT( stats[b] > 0 );
1374        }
1375    }
1376    else
1377    {
1378        int statistically_safe_all_the_way =
1379            is_significantly_above_a_power_of_2( bound_bytes );
1380        for( b = 0; b < n_bits; b++ )
1381        {
1382            mbedtls_test_set_step( 1000000 + b );
1383            /* Assert that each bit has been set in at least one result and
1384             * clear in at least one result. Provided that iterations is not
1385             * too small, it would be extremely unlikely for this not to be
1386             * the case if the results are uniformly distributed.
1387             *
1388             * As an exception, the top bit may legitimately never be set
1389             * if bound is a power of 2 or only slightly above.
1390             */
1391            if( statistically_safe_all_the_way || b != n_bits - 1 )
1392            {
1393                TEST_ASSERT( stats[b] > 0 );
1394            }
1395            TEST_ASSERT( stats[b] < (size_t) iterations );
1396        }
1397    }
1398
1399exit:
1400    mbedtls_mpi_free( &upper_bound );
1401    mbedtls_mpi_free( &result );
1402    mbedtls_free( stats );
1403}
1404/* END_CASE */
1405
1406/* BEGIN_CASE */
1407void mpi_random_sizes( int min, data_t *bound_bytes, int nlimbs, int before )
1408{
1409    mbedtls_mpi upper_bound;
1410    mbedtls_mpi result;
1411
1412    mbedtls_mpi_init( &upper_bound );
1413    mbedtls_mpi_init( &result );
1414
1415    if( before != 0 )
1416    {
1417        /* Set result to sign(before) * 2^(|before|-1) */
1418        TEST_ASSERT( mbedtls_mpi_lset( &result, before > 0 ? 1 : -1 ) == 0 );
1419        if( before < 0 )
1420            before = - before;
1421        TEST_ASSERT( mbedtls_mpi_shift_l( &result, before - 1 ) == 0 );
1422    }
1423
1424    TEST_EQUAL( 0, mbedtls_mpi_grow( &result, nlimbs ) );
1425    TEST_EQUAL( 0, mbedtls_mpi_read_binary( &upper_bound,
1426                                            bound_bytes->x, bound_bytes->len ) );
1427    TEST_EQUAL( 0, mbedtls_mpi_random( &result, min, &upper_bound,
1428                                       mbedtls_test_rnd_std_rand, NULL ) );
1429    TEST_ASSERT( sign_is_valid( &result ) );
1430    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &result, &upper_bound ) < 0 );
1431    TEST_ASSERT( mbedtls_mpi_cmp_int( &result, min ) >= 0 );
1432
1433exit:
1434    mbedtls_mpi_free( &upper_bound );
1435    mbedtls_mpi_free( &result );
1436}
1437/* END_CASE */
1438
1439/* BEGIN_CASE */
1440void mpi_random_fail( int min, data_t *bound_bytes, int expected_ret )
1441{
1442    mbedtls_mpi upper_bound;
1443    mbedtls_mpi result;
1444    int actual_ret;
1445
1446    mbedtls_mpi_init( &upper_bound );
1447    mbedtls_mpi_init( &result );
1448
1449    TEST_EQUAL( 0, mbedtls_mpi_read_binary( &upper_bound,
1450                                            bound_bytes->x, bound_bytes->len ) );
1451    actual_ret = mbedtls_mpi_random( &result, min, &upper_bound,
1452                                     mbedtls_test_rnd_std_rand, NULL );
1453    TEST_EQUAL( expected_ret, actual_ret );
1454
1455exit:
1456    mbedtls_mpi_free( &upper_bound );
1457    mbedtls_mpi_free( &result );
1458}
1459/* END_CASE */
1460
1461/* BEGIN_CASE */
1462void most_negative_mpi_sint( )
1463{
1464    /* Ad hoc tests for n = -p = -2^(biL-1) as a mbedtls_mpi_sint. We
1465     * guarantee that mbedtls_mpi_sint is a two's complement type, so this
1466     * is a valid value. However, negating it (`-n`) has undefined behavior
1467     * (although in practice `-n` evaluates to the value n).
1468     *
1469     * This function has ad hoc tests for this value. It's separated from other
1470     * functions because the test framework makes it hard to pass this value
1471     * into test cases.
1472     *
1473     * In the comments here:
1474     * - biL = number of bits in limbs
1475     * - p = 2^(biL-1) (smallest positive value not in mbedtls_mpi_sint range)
1476     * - n = -2^(biL-1) (largest negative value in mbedtls_mpi_sint range)
1477     */
1478
1479    mbedtls_mpi A, R, X;
1480    mbedtls_mpi_init( &A );
1481    mbedtls_mpi_init( &R );
1482    mbedtls_mpi_init( &X );
1483
1484    const size_t biL = 8 * sizeof( mbedtls_mpi_sint );
1485    mbedtls_mpi_uint most_positive_plus_1 = (mbedtls_mpi_uint) 1 << ( biL - 1 );
1486    const mbedtls_mpi_sint most_positive = most_positive_plus_1 - 1;
1487    const mbedtls_mpi_sint most_negative = - most_positive - 1;
1488    TEST_EQUAL( (mbedtls_mpi_uint) most_negative,
1489                (mbedtls_mpi_uint) 1 << ( biL - 1 ) );
1490    TEST_EQUAL( (mbedtls_mpi_uint) most_negative << 1, 0 );
1491
1492    /* Test mbedtls_mpi_lset() */
1493    TEST_EQUAL( mbedtls_mpi_lset( &A, most_negative ), 0 );
1494    TEST_EQUAL( A.s, -1 );
1495    TEST_EQUAL( A.n, 1 );
1496    TEST_EQUAL( A.p[0], most_positive_plus_1 );
1497
1498    /* Test mbedtls_mpi_cmp_int(): -p == -p */
1499    TEST_EQUAL( mbedtls_mpi_cmp_int( &A, most_negative ), 0 );
1500
1501    /* Test mbedtls_mpi_cmp_int(): -(p+1) < -p */
1502    A.p[0] = most_positive_plus_1 + 1;
1503    TEST_EQUAL( mbedtls_mpi_cmp_int( &A, most_negative ), -1 );
1504
1505    /* Test mbedtls_mpi_cmp_int(): -(p-1) > -p */
1506    A.p[0] = most_positive_plus_1 - 1;
1507    TEST_EQUAL( mbedtls_mpi_cmp_int( &A, most_negative ), 1 );
1508
1509    /* Test mbedtls_mpi_add_int(): (p-1) + (-p) */
1510    TEST_EQUAL( mbedtls_mpi_lset( &A, most_positive ), 0 );
1511    TEST_EQUAL( mbedtls_mpi_add_int( &X, &A, most_negative ), 0 );
1512    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, -1 ), 0 );
1513
1514    /* Test mbedtls_mpi_add_int(): (0) + (-p) */
1515    TEST_EQUAL( mbedtls_mpi_lset( &A, 0 ), 0 );
1516    TEST_EQUAL( mbedtls_mpi_add_int( &X, &A, most_negative ), 0 );
1517    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, most_negative ), 0 );
1518
1519    /* Test mbedtls_mpi_add_int(): (-p) + (-p) */
1520    TEST_EQUAL( mbedtls_mpi_lset( &A, most_negative ), 0 );
1521    TEST_EQUAL( mbedtls_mpi_add_int( &X, &A, most_negative ), 0 );
1522    TEST_EQUAL( X.s, -1 );
1523    TEST_EQUAL( X.n, 2 );
1524    TEST_EQUAL( X.p[0], 0 );
1525    TEST_EQUAL( X.p[1], 1 );
1526
1527    /* Test mbedtls_mpi_sub_int(): (p) - (-p) */
1528    mbedtls_mpi_free( &X );
1529    TEST_EQUAL( mbedtls_mpi_lset( &A, most_positive ), 0 );
1530    TEST_EQUAL( mbedtls_mpi_sub_int( &X, &A, most_negative ), 0 );
1531    TEST_EQUAL( X.s, 1 );
1532    TEST_EQUAL( X.n, 1 );
1533    TEST_EQUAL( X.p[0], ~(mbedtls_mpi_uint)0 );
1534
1535    /* Test mbedtls_mpi_sub_int(): (0) - (-p) */
1536    TEST_EQUAL( mbedtls_mpi_lset( &A, 0 ), 0 );
1537    TEST_EQUAL( mbedtls_mpi_sub_int( &X, &A, most_negative ), 0 );
1538    TEST_EQUAL( X.s, 1 );
1539    TEST_EQUAL( X.n, 1 );
1540    TEST_EQUAL( X.p[0], most_positive_plus_1 );
1541
1542    /* Test mbedtls_mpi_sub_int(): (-p) - (-p) */
1543    TEST_EQUAL( mbedtls_mpi_lset( &A, most_negative ), 0 );
1544    TEST_EQUAL( mbedtls_mpi_sub_int( &X, &A, most_negative ), 0 );
1545    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, 0 ), 0 );
1546
1547    /* Test mbedtls_mpi_div_int(): (-p+1) / (-p) */
1548    TEST_EQUAL( mbedtls_mpi_lset( &A, -most_positive ), 0 );
1549    TEST_EQUAL( mbedtls_mpi_div_int( &X, &R, &A, most_negative ), 0 );
1550    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, 0 ), 0 );
1551    TEST_EQUAL( mbedtls_mpi_cmp_int( &R, -most_positive ), 0 );
1552
1553    /* Test mbedtls_mpi_div_int(): (-p) / (-p) */
1554    TEST_EQUAL( mbedtls_mpi_lset( &A, most_negative ), 0 );
1555    TEST_EQUAL( mbedtls_mpi_div_int( &X, &R, &A, most_negative ), 0 );
1556    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, 1 ), 0 );
1557    TEST_EQUAL( mbedtls_mpi_cmp_int( &R, 0 ), 0 );
1558
1559    /* Test mbedtls_mpi_div_int(): (-2*p) / (-p) */
1560    TEST_EQUAL( mbedtls_mpi_shift_l( &A, 1 ), 0 );
1561    TEST_EQUAL( mbedtls_mpi_div_int( &X, &R, &A, most_negative ), 0 );
1562    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, 2 ), 0 );
1563    TEST_EQUAL( mbedtls_mpi_cmp_int( &R, 0 ), 0 );
1564
1565    /* Test mbedtls_mpi_div_int(): (-2*p+1) / (-p) */
1566    TEST_EQUAL( mbedtls_mpi_add_int( &A, &A, 1 ), 0 );
1567    TEST_EQUAL( mbedtls_mpi_div_int( &X, &R, &A, most_negative ), 0 );
1568    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, 1 ), 0 );
1569    TEST_EQUAL( mbedtls_mpi_cmp_int( &R, -most_positive ), 0 );
1570
1571    /* Test mbedtls_mpi_div_int(): (p-1) / (-p) */
1572    TEST_EQUAL( mbedtls_mpi_lset( &A, most_positive ), 0 );
1573    TEST_EQUAL( mbedtls_mpi_div_int( &X, &R, &A, most_negative ), 0 );
1574    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, 0 ), 0 );
1575    TEST_EQUAL( mbedtls_mpi_cmp_int( &R, most_positive ), 0 );
1576
1577    /* Test mbedtls_mpi_div_int(): (p) / (-p) */
1578    TEST_EQUAL( mbedtls_mpi_add_int( &A, &A, 1 ), 0 );
1579    TEST_EQUAL( mbedtls_mpi_div_int( &X, &R, &A, most_negative ), 0 );
1580    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, -1 ), 0 );
1581    TEST_EQUAL( mbedtls_mpi_cmp_int( &R, 0 ), 0 );
1582
1583    /* Test mbedtls_mpi_div_int(): (2*p) / (-p) */
1584    TEST_EQUAL( mbedtls_mpi_shift_l( &A, 1 ), 0 );
1585    TEST_EQUAL( mbedtls_mpi_div_int( &X, &R, &A, most_negative ), 0 );
1586    TEST_EQUAL( mbedtls_mpi_cmp_int( &X, -2 ), 0 );
1587    TEST_EQUAL( mbedtls_mpi_cmp_int( &R, 0 ), 0 );
1588
1589    /* Test mbedtls_mpi_mod_int(): never valid */
1590    TEST_EQUAL( mbedtls_mpi_mod_int( X.p, &A, most_negative ),
1591                MBEDTLS_ERR_MPI_NEGATIVE_VALUE );
1592
1593    /* Test mbedtls_mpi_random(): never valid */
1594    TEST_EQUAL( mbedtls_mpi_random( &X, most_negative, &A,
1595                                    mbedtls_test_rnd_std_rand, NULL ),
1596                MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
1597
1598exit:
1599    mbedtls_mpi_free( &A );
1600    mbedtls_mpi_free( &R );
1601    mbedtls_mpi_free( &X );
1602}
1603/* END_CASE */
1604
1605/* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */
1606void mpi_selftest(  )
1607{
1608    TEST_ASSERT( mbedtls_mpi_self_test( 1 ) == 0 );
1609}
1610/* END_CASE */
1611