mbedtls/tests/suites/test_suite_entropy.function
Paul Bakker ffbfb4c24c Add test cases for NV seed functionality
A standard 'test' that writes a seed file is added so that regular tests
still can succeed. This is in lieu of a 'SUITE_PRE_CODE' kind of
arrangement where a suite can run code before (and after) all other code
runs.

A test is added that checks if we can read and write the standard NV
seed file

A test is added that actually checks if the entropy and seed file values
that are the result of just using the NV seed are the same as the manual
calculation.
2016-06-01 16:34:50 +01:00

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/* BEGIN_HEADER */
#include "mbedtls/entropy.h"
#include "mbedtls/entropy_poll.h"
/*
* Number of calls made to entropy_dummy_source()
*/
static size_t entropy_dummy_calls;
/*
* Dummy entropy source
*
* If data is NULL, write exactly the requested length.
* Otherwise, write the length indicated by data or error if negative
*/
static int entropy_dummy_source( void *data, unsigned char *output,
size_t len, size_t *olen )
{
entropy_dummy_calls++;
if( data == NULL )
*olen = len;
else
{
int *d = (int *) data;
if( *d < 0 )
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
else
*olen = *d;
}
memset( output, 0x2a, *olen );
return( 0 );
}
/*
* Ability to clear entropy sources to allow testing with just predefined
* entropy sources. This function or tests depending on it might break if there
* are internal changes to how entropy sources are registered.
*
* To be called immediately after mbedtls_entropy_init().
*
* Just resetting the counter. New sources will overwrite existing ones.
* This might break memory checks in the future if sources need 'free-ing' then
* as well.
*/
static void entropy_clear_sources( mbedtls_entropy_context *ctx )
{
ctx->source_count = 0;
}
/*
* NV seed read/write functions that use a buffer instead of a file
*/
static unsigned char buffer_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
static int buffer_nv_seed_read( unsigned char *buf, size_t buf_len )
{
if( buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE )
return( -1 );
memcpy( buf, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE );
return( 0 );
}
static int buffer_nv_seed_write( unsigned char *buf, size_t buf_len )
{
if( buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE )
return( -1 );
memcpy( buffer_seed, buf, MBEDTLS_ENTROPY_BLOCK_SIZE );
return( 0 );
}
/*
* NV seed read/write helpers that fill the base seedfile
*/
static int write_nv_seed( unsigned char *buf, size_t buf_len )
{
FILE *f;
if( buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE )
return( -1 );
if( ( f = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL )
return( -1 );
if( fwrite( buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f ) !=
MBEDTLS_ENTROPY_BLOCK_SIZE )
return( -1 );
fclose( f );
return( 0 );
}
static int read_nv_seed( unsigned char *buf, size_t buf_len )
{
FILE *f;
if( buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE )
return( -1 );
if( ( f = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL )
return( -1 );
if( fread( buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f ) !=
MBEDTLS_ENTROPY_BLOCK_SIZE )
return( -1 );
fclose( f );
return( 0 );
}
/* END_HEADER */
/* BEGIN_DEPENDENCIES
* depends_on:MBEDTLS_ENTROPY_C
* END_DEPENDENCIES
*/
/* BEGIN_CASE depends_on:MBEDTLS_FS_IO */
void entropy_seed_file( char *path, int ret )
{
mbedtls_entropy_context ctx;
mbedtls_entropy_init( &ctx );
TEST_ASSERT( mbedtls_entropy_write_seed_file( &ctx, path ) == ret );
TEST_ASSERT( mbedtls_entropy_update_seed_file( &ctx, path ) == ret );
exit:
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void entropy_too_many_sources( )
{
mbedtls_entropy_context ctx;
size_t i;
mbedtls_entropy_init( &ctx );
/*
* It's hard to tell precisely when the error will occur,
* since we don't know how many sources were automatically added.
*/
for( i = 0; i < MBEDTLS_ENTROPY_MAX_SOURCES; i++ )
(void) mbedtls_entropy_add_source( &ctx, entropy_dummy_source, NULL,
16, MBEDTLS_ENTROPY_SOURCE_WEAK );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source, NULL,
16, MBEDTLS_ENTROPY_SOURCE_WEAK )
== MBEDTLS_ERR_ENTROPY_MAX_SOURCES );
exit:
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void entropy_func_len( int len, int ret )
{
mbedtls_entropy_context ctx;
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE + 10] = { 0 };
unsigned char acc[MBEDTLS_ENTROPY_BLOCK_SIZE + 10] = { 0 };
size_t i, j;
mbedtls_entropy_init( &ctx );
/*
* See comments in mbedtls_entropy_self_test()
*/
for( i = 0; i < 8; i++ )
{
TEST_ASSERT( mbedtls_entropy_func( &ctx, buf, len ) == ret );
for( j = 0; j < sizeof( buf ); j++ )
acc[j] |= buf[j];
}
if( ret == 0 )
for( j = 0; j < (size_t) len; j++ )
TEST_ASSERT( acc[j] != 0 );
for( j = len; j < sizeof( buf ); j++ )
TEST_ASSERT( acc[j] == 0 );
}
/* END_CASE */
/* BEGIN_CASE */
void entropy_source_fail( char *path )
{
mbedtls_entropy_context ctx;
int fail = -1;
unsigned char buf[16];
mbedtls_entropy_init( &ctx );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source,
&fail, 16,
MBEDTLS_ENTROPY_SOURCE_WEAK )
== 0 );
TEST_ASSERT( mbedtls_entropy_func( &ctx, buf, sizeof( buf ) )
== MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
TEST_ASSERT( mbedtls_entropy_gather( &ctx )
== MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
#if defined(MBEDTLS_FS_IO)
TEST_ASSERT( mbedtls_entropy_write_seed_file( &ctx, path )
== MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
TEST_ASSERT( mbedtls_entropy_update_seed_file( &ctx, path )
== MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
#else
((void) path);
#endif
exit:
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void entropy_threshold( int threshold, int chunk_size, int result )
{
mbedtls_entropy_context ctx;
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
int ret;
mbedtls_entropy_init( &ctx );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source,
&chunk_size, threshold,
MBEDTLS_ENTROPY_SOURCE_WEAK ) == 0 );
entropy_dummy_calls = 0;
ret = mbedtls_entropy_func( &ctx, buf, sizeof( buf ) );
if( result >= 0 )
{
TEST_ASSERT( ret == 0 );
#if defined(MBEDTLS_ENTROPY_NV_SEED)
// Two times as much calls due to the NV seed update
result *= 2;
#endif
TEST_ASSERT( entropy_dummy_calls == (size_t) result );
}
else
{
TEST_ASSERT( ret == result );
}
exit:
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
void nv_seed_file_create()
{
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
TEST_ASSERT( write_nv_seed( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
void entropy_nv_seed_std_io()
{
unsigned char io_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
unsigned char check_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
memset( io_seed, 1, MBEDTLS_ENTROPY_BLOCK_SIZE );
memset( check_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
mbedtls_platform_set_nv_seed( mbedtls_platform_std_nv_seed_read,
mbedtls_platform_std_nv_seed_write );
/* Check if platform NV read and write manipulate the same data */
TEST_ASSERT( write_nv_seed( io_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
TEST_ASSERT( mbedtls_nv_seed_read( check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) ==
MBEDTLS_ENTROPY_BLOCK_SIZE );
TEST_ASSERT( memcmp( io_seed, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
memset( check_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
/* Check if platform NV write and raw read manipulate the same data */
TEST_ASSERT( mbedtls_nv_seed_write( io_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) ==
MBEDTLS_ENTROPY_BLOCK_SIZE );
TEST_ASSERT( read_nv_seed( check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
TEST_ASSERT( memcmp( io_seed, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_PLATFORM_NV_SEED_ALT:MBEDTLS_SHA512_C */
void entropy_nv_seed( char *read_seed_str )
{
mbedtls_sha512_context accumulator;
mbedtls_entropy_context ctx;
unsigned char header[2];
unsigned char entropy[MBEDTLS_ENTROPY_BLOCK_SIZE];
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
unsigned char empty[MBEDTLS_ENTROPY_BLOCK_SIZE];
unsigned char read_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
unsigned char check_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
unsigned char check_entropy[MBEDTLS_ENTROPY_BLOCK_SIZE];
memset( entropy, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
memset( buffer_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
memset( empty, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
memset( check_seed, 2, MBEDTLS_ENTROPY_BLOCK_SIZE );
memset( check_entropy, 3, MBEDTLS_ENTROPY_BLOCK_SIZE );
// Set the initial NV seed to read
unhexify( read_seed, read_seed_str );
memcpy( buffer_seed, read_seed, MBEDTLS_ENTROPY_BLOCK_SIZE );
// Make sure we read/write NV seed from our buffers
mbedtls_platform_set_nv_seed( buffer_nv_seed_read, buffer_nv_seed_write );
mbedtls_entropy_init( &ctx );
entropy_clear_sources( &ctx );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, mbedtls_nv_seed_poll, NULL,
MBEDTLS_ENTROPY_BLOCK_SIZE,
MBEDTLS_ENTROPY_SOURCE_STRONG ) == 0 );
// Do an entropy run
TEST_ASSERT( mbedtls_entropy_func( &ctx, entropy, sizeof( entropy ) ) == 0 );
// Determine what should have happened with manual entropy internal logic
// Only use the SHA-512 version to check
// Init accumulator
header[1] = MBEDTLS_ENTROPY_BLOCK_SIZE;
mbedtls_sha512_starts( &accumulator, 0 );
// First run for updating write_seed
header[0] = 0;
mbedtls_sha512_update( &accumulator, header, 2 );
mbedtls_sha512_update( &accumulator, read_seed, MBEDTLS_ENTROPY_BLOCK_SIZE );
mbedtls_sha512_finish( &accumulator, buf );
memset( &accumulator, 0, sizeof( mbedtls_sha512_context ) );
mbedtls_sha512_starts( &accumulator, 0 );
mbedtls_sha512_update( &accumulator, buf, MBEDTLS_ENTROPY_BLOCK_SIZE );
mbedtls_sha512( buf, MBEDTLS_ENTROPY_BLOCK_SIZE, check_seed, 0 );
// Second run for actual entropy (triggers mbedtls_entropy_update_nv_seed)
header[0] = MBEDTLS_ENTROPY_SOURCE_MANUAL;
mbedtls_sha512_update( &accumulator, header, 2 );
mbedtls_sha512_update( &accumulator, empty, MBEDTLS_ENTROPY_BLOCK_SIZE );
header[0] = 0;
mbedtls_sha512_update( &accumulator, header, 2 );
mbedtls_sha512_update( &accumulator, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE );
mbedtls_sha512_finish( &accumulator, buf );
mbedtls_sha512( buf, MBEDTLS_ENTROPY_BLOCK_SIZE, check_entropy, 0 );
// Check result of both NV file and entropy received with the manual calculations
TEST_ASSERT( memcmp( check_seed, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
TEST_ASSERT( memcmp( check_entropy, entropy, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */
void entropy_selftest( )
{
TEST_ASSERT( mbedtls_entropy_self_test( 0 ) == 0 );
}
/* END_CASE */