| Werner Lewis | 0c6ea12 | 2022-09-30 13:02:16 +0100 | [diff] [blame^] | 1 | /* BEGIN_HEADER */ |
| 2 | #include "mbedtls/bignum.h" |
| 3 | #include "mbedtls/entropy.h" |
| 4 | #include "bignum_mod.h" |
| 5 | #include "constant_time_internal.h" |
| 6 | #include "test/constant_flow.h" |
| 7 | |
| 8 | /* Check the validity of the sign bit in an MPI object. Reject representations |
| 9 | * that are not supported by the rest of the library and indicate a bug when |
| 10 | * constructing the value. */ |
| 11 | static int sign_is_valid( const mbedtls_mpi *X ) |
| 12 | { |
| 13 | if( X->s != 1 && X->s != -1 ) |
| 14 | return( 0 ); // invalid sign bit, e.g. 0 |
| 15 | if( mbedtls_mpi_bitlen( X ) == 0 && X->s != 1 ) |
| 16 | return( 0 ); // negative zero |
| 17 | return( 1 ); |
| 18 | } |
| 19 | |
| 20 | /* END_HEADER */ |
| 21 | |
| 22 | /* BEGIN_DEPENDENCIES |
| 23 | * depends_on:MBEDTLS_BIGNUM_C |
| 24 | * END_DEPENDENCIES |
| 25 | */ |
| 26 | |
| 27 | /* BEGIN_CASE */ |
| 28 | void mpi_mod_setup( int ext_rep, int int_rep, int iret ) |
| 29 | { |
| 30 | #define MLIMBS 8 |
| 31 | mbedtls_mpi_uint mp[MLIMBS]; |
| 32 | mbedtls_mpi_mod_modulus m; |
| 33 | int ret; |
| 34 | |
| 35 | memset( mp, 0xFF, sizeof(mp) ); |
| 36 | |
| 37 | mbedtls_mpi_mod_modulus_init( &m ); |
| 38 | ret = mbedtls_mpi_mod_modulus_setup( &m, mp, MLIMBS, ext_rep, int_rep ); |
| 39 | TEST_EQUAL( ret, iret ); |
| 40 | |
| 41 | /* Address sanitiser should catch if we try to free mp */ |
| 42 | mbedtls_mpi_mod_modulus_free( &m ); |
| 43 | |
| 44 | /* Make sure that the modulus doesn't have reference to mp anymore */ |
| 45 | TEST_ASSERT( m.p != mp ); |
| 46 | |
| 47 | exit: |
| 48 | /* It should be safe to call an mbedtls free several times */ |
| 49 | mbedtls_mpi_mod_modulus_free( &m ); |
| 50 | |
| 51 | #undef MLIMBS |
| 52 | } |
| 53 | /* END_CASE */ |
| 54 | |
| 55 | |
| 56 | /* BEGIN_CASE */ |
| 57 | void mpi_mod_mpi( char * input_X, char * input_Y, |
| 58 | char * input_A, int div_result ) |
| 59 | { |
| 60 | mbedtls_mpi X, Y, A; |
| 61 | int res; |
| 62 | mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &A ); |
| 63 | |
| 64 | TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 ); |
| 65 | TEST_ASSERT( mbedtls_test_read_mpi( &Y, input_Y ) == 0 ); |
| 66 | TEST_ASSERT( mbedtls_test_read_mpi( &A, input_A ) == 0 ); |
| 67 | res = mbedtls_mpi_mod_mpi( &X, &X, &Y ); |
| 68 | TEST_ASSERT( res == div_result ); |
| 69 | if( res == 0 ) |
| 70 | { |
| 71 | TEST_ASSERT( sign_is_valid( &X ) ); |
| 72 | TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 ); |
| 73 | } |
| 74 | |
| 75 | exit: |
| 76 | mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &A ); |
| 77 | } |
| 78 | /* END_CASE */ |
| 79 | |
| 80 | /* BEGIN_CASE */ |
| 81 | void mpi_mod_int( char * input_X, int input_Y, |
| 82 | int input_A, int div_result ) |
| 83 | { |
| 84 | mbedtls_mpi X; |
| 85 | int res; |
| 86 | mbedtls_mpi_uint r; |
| 87 | mbedtls_mpi_init( &X ); |
| 88 | |
| 89 | TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 ); |
| 90 | res = mbedtls_mpi_mod_int( &r, &X, input_Y ); |
| 91 | TEST_ASSERT( res == div_result ); |
| 92 | if( res == 0 ) |
| 93 | { |
| 94 | TEST_ASSERT( r == (mbedtls_mpi_uint) input_A ); |
| 95 | } |
| 96 | |
| 97 | exit: |
| 98 | mbedtls_mpi_free( &X ); |
| 99 | } |
| 100 | /* END_CASE */ |