mbedtls/tests/suites/test_suite_psa_crypto_entropy.function

/* BEGIN_HEADER */
#include <stdint.h>

#include "mbedtls/entropy.h"
#include "mbedtls/entropy_poll.h"

#include "psa_crypto_helpers.h"
#if defined(MBEDTLS_PSA_ITS_FILE_C)
#include <stdio.h>
#else
#include <psa/internal_trusted_storage.h>
#endif

/* Calculating the minimum allowed entropy size in bytes */
#define MBEDTLS_PSA_INJECT_ENTROPY_MIN_SIZE MAX(MBEDTLS_ENTROPY_MIN_PLATFORM, MBEDTLS_ENTROPY_BLOCK_SIZE)

/* Remove the entropy seed file. Since the library does not expose a way
 * to do this (it would be a security risk if such a function was ever
 * accessible in production), implement this functionality in a white-box
 * manner. */
psa_status_t remove_seed_file( void )
{
#if defined(MBEDTLS_PSA_ITS_FILE_C)
    if( remove( "00000000ffffff52.psa_its" ) == 0 )
        return( PSA_SUCCESS );
    else
        return( PSA_ERROR_DOES_NOT_EXIST );
#else
    return( psa_its_remove( PSA_CRYPTO_ITS_RANDOM_SEED_UID ) );
#endif
}

/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_PSA_INJECT_ENTROPY
 * END_DEPENDENCIES
 */

/* BEGIN_CASE */
void validate_entropy_seed_injection( int seed_length_a,
                                      int expected_status_a,
                                      int seed_length_b,
                                      int expected_status_b )
{
    psa_status_t status;
    uint8_t output[32] = { 0 };
    uint8_t zeros[32] = { 0 };
    uint8_t *seed = NULL;
    int i;
    int seed_size;
    if( seed_length_a > seed_length_b )
    {
        seed_size = seed_length_a;
    }
    else
    {
        seed_size = seed_length_b;
    }
    ASSERT_ALLOC( seed, seed_size );
    /* fill seed with some data */
    for( i = 0; i < seed_size; ++i )
    {
        seed[i] = i;
    }
    status =  remove_seed_file( );
    TEST_ASSERT( ( status == PSA_SUCCESS ) ||
                 ( status == PSA_ERROR_DOES_NOT_EXIST ) );
    status = mbedtls_psa_inject_entropy( seed, seed_length_a );
    TEST_EQUAL( status, expected_status_a );
    status = mbedtls_psa_inject_entropy( seed, seed_length_b );
    TEST_EQUAL( status, expected_status_b );
    PSA_ASSERT( psa_crypto_init( ) );
    PSA_ASSERT( psa_generate_random( output,
                                     sizeof( output ) ) );
    TEST_ASSERT( memcmp( output, zeros, sizeof( output ) ) != 0 );
exit:
    mbedtls_free( seed );
    remove_seed_file( );
    PSA_DONE( );
}
/* END_CASE */

/* BEGIN_CASE */
void run_entropy_inject_with_crypto_init( )
{
    psa_status_t status;
    size_t i;
    uint8_t seed[MBEDTLS_PSA_INJECT_ENTROPY_MIN_SIZE] = { 0 };
    /* fill seed with some data */
    for( i = 0; i < sizeof( seed ); ++i )
    {
        seed[i] = i;
    }
    status =  remove_seed_file( );
    TEST_ASSERT( ( status == PSA_SUCCESS ) ||
                 ( status == PSA_ERROR_DOES_NOT_EXIST ) );
    status = mbedtls_psa_inject_entropy( seed, sizeof( seed ) );
    PSA_ASSERT( status );
    status =  remove_seed_file( );
    TEST_EQUAL( status, PSA_SUCCESS );
    status = psa_crypto_init( );
    TEST_EQUAL( status, PSA_ERROR_INSUFFICIENT_ENTROPY );
    status = mbedtls_psa_inject_entropy( seed, sizeof( seed ) );
    PSA_ASSERT( status );
    status = psa_crypto_init( );
    PSA_ASSERT( status );
    PSA_DONE( );
    /* The seed is written by nv_seed callback functions therefore the injection will fail */
    status = mbedtls_psa_inject_entropy( seed, sizeof( seed ) );
    TEST_EQUAL( status, PSA_ERROR_NOT_PERMITTED );
exit:
    remove_seed_file( );
    PSA_DONE( );
}
/* END_CASE */