mbedtls/tests/suites/test_suite_entropy.function
Gilles Peskine 7aba036154 Add missing cleanup in test function
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-02-22 19:24:03 +01:00

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/* BEGIN_HEADER */
#include "mbedtls/entropy.h"
#include "mbedtls/entropy_poll.h"
#include "mbedtls/md.h"
#include "string.h"
typedef enum
{
DUMMY_CONSTANT_LENGTH, /* Output context->length bytes */
DUMMY_REQUESTED_LENGTH, /* Output whatever length was requested */
DUMMY_FAIL, /* Return an error code */
} entropy_dummy_instruction;
typedef struct
{
entropy_dummy_instruction instruction;
size_t length; /* Length to return for DUMMY_CONSTANT_LENGTH */
size_t calls; /* Incremented at each call */
} entropy_dummy_context;
/*
* 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 *arg, unsigned char *output,
size_t len, size_t *olen )
{
entropy_dummy_context *context = arg;
++context->calls;
switch( context->instruction )
{
case DUMMY_CONSTANT_LENGTH:
*olen = context->length;
break;
case DUMMY_REQUESTED_LENGTH:
*olen = len;
break;
case DUMMY_FAIL:
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
}
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;
}
#if defined(MBEDTLS_ENTROPY_NV_SEED)
/*
* NV seed read/write functions that use a buffer instead of a file
*/
static unsigned char buffer_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
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 );
}
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 );
}
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 );
}
#endif /* MBEDTLS_ENTROPY_NV_SEED */
/* END_HEADER */
/* BEGIN_DEPENDENCIES
* depends_on:MBEDTLS_ENTROPY_C
* END_DEPENDENCIES
*/
/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED: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_no_sources( )
{
mbedtls_entropy_context ctx;
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
mbedtls_entropy_init( &ctx );
entropy_clear_sources( &ctx );
TEST_EQUAL( mbedtls_entropy_func( &ctx, buf, sizeof( buf ) ),
MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED );
exit:
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void entropy_too_many_sources( )
{
mbedtls_entropy_context ctx;
size_t i;
entropy_dummy_context dummy = {DUMMY_REQUESTED_LENGTH, 0, 0};
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, &dummy,
16, MBEDTLS_ENTROPY_SOURCE_WEAK );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source, &dummy,
16, MBEDTLS_ENTROPY_SOURCE_WEAK )
== MBEDTLS_ERR_ENTROPY_MAX_SOURCES );
exit:
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE depends_on:ENTROPY_HAVE_STRONG */
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 );
exit:
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void entropy_source_fail( char * path )
{
mbedtls_entropy_context ctx;
unsigned char buf[16];
entropy_dummy_context dummy = {DUMMY_FAIL, 0, 0};
mbedtls_entropy_init( &ctx );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source,
&dummy, 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) && defined(MBEDTLS_ENTROPY_NV_SEED)
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;
entropy_dummy_context strong =
{DUMMY_CONSTANT_LENGTH, MBEDTLS_ENTROPY_BLOCK_SIZE, 0};
entropy_dummy_context weak = {DUMMY_CONSTANT_LENGTH, chunk_size, 0};
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
int ret;
mbedtls_entropy_init( &ctx );
entropy_clear_sources( &ctx );
/* Set strong source that reaches its threshold immediately and
* a weak source whose threshold is a test parameter. */
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source,
&strong, 1,
MBEDTLS_ENTROPY_SOURCE_STRONG ) == 0 );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source,
&weak, threshold,
MBEDTLS_ENTROPY_SOURCE_WEAK ) == 0 );
ret = mbedtls_entropy_func( &ctx, buf, sizeof( buf ) );
if( result >= 0 )
{
TEST_ASSERT( ret == 0 );
#if defined(MBEDTLS_ENTROPY_NV_SEED)
/* If the NV seed functionality is enabled, there are two entropy
* updates: before and after updating the NV seed. */
result *= 2;
#endif
TEST_ASSERT( weak.calls == (size_t) result );
}
else
{
TEST_ASSERT( ret == result );
}
exit:
mbedtls_entropy_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void entropy_calls( int strength1, int strength2,
int threshold, int chunk_size,
int result )
{
/*
* if result >= 0: result = expected number of calls to source 1
* if result < 0: result = expected return code from mbedtls_entropy_func()
*/
mbedtls_entropy_context ctx;
entropy_dummy_context dummy1 = {DUMMY_CONSTANT_LENGTH, chunk_size, 0};
entropy_dummy_context dummy2 = {DUMMY_CONSTANT_LENGTH, chunk_size, 0};
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
int ret;
mbedtls_entropy_init( &ctx );
entropy_clear_sources( &ctx );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source,
&dummy1, threshold,
strength1 ) == 0 );
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source,
&dummy2, threshold,
strength2 ) == 0 );
ret = mbedtls_entropy_func( &ctx, buf, sizeof( buf ) );
if( result >= 0 )
{
TEST_ASSERT( ret == 0 );
#if defined(MBEDTLS_ENTROPY_NV_SEED)
/* If the NV seed functionality is enabled, there are two entropy
* updates: before and after updating the NV seed. */
result *= 2;
#endif
TEST_ASSERT( dummy1.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:MBEDTLS_PLATFORM_NV_SEED_ALT */
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_MD_C:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_PLATFORM_NV_SEED_ALT */
void entropy_nv_seed( data_t * read_seed )
{
#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
const mbedtls_md_info_t *md_info =
mbedtls_md_info_from_type( MBEDTLS_MD_SHA512 );
#elif defined(MBEDTLS_ENTROPY_SHA256_ACCUMULATOR)
const mbedtls_md_info_t *md_info =
mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 );
#else
#error "Unsupported entropy accumulator"
#endif
mbedtls_md_context_t accumulator;
mbedtls_entropy_context ctx;
int (*original_mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len ) =
mbedtls_nv_seed_read;
int (*original_mbedtls_nv_seed_write)( unsigned char *buf, size_t buf_len ) =
mbedtls_nv_seed_write;
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 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( empty, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
memset( check_seed, 2, MBEDTLS_ENTROPY_BLOCK_SIZE );
memset( check_entropy, 3, 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_md_init( &accumulator );
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 );
// Set the initial NV seed to read
TEST_ASSERT( read_seed->len >= MBEDTLS_ENTROPY_BLOCK_SIZE );
memcpy( buffer_seed, read_seed->x, MBEDTLS_ENTROPY_BLOCK_SIZE );
// Do an entropy run
TEST_ASSERT( mbedtls_entropy_func( &ctx, entropy, sizeof( entropy ) ) == 0 );
// Determine what should have happened with manual entropy internal logic
// Init accumulator
header[1] = MBEDTLS_ENTROPY_BLOCK_SIZE;
TEST_ASSERT( mbedtls_md_setup( &accumulator, md_info, 0 ) == 0 );
// First run for updating write_seed
header[0] = 0;
TEST_ASSERT( mbedtls_md_starts( &accumulator ) == 0 );
TEST_ASSERT( mbedtls_md_update( &accumulator, header, 2 ) == 0 );
TEST_ASSERT( mbedtls_md_update( &accumulator,
read_seed->x, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
TEST_ASSERT( mbedtls_md_finish( &accumulator, buf ) == 0 );
TEST_ASSERT( mbedtls_md_starts( &accumulator ) == 0 );
TEST_ASSERT( mbedtls_md_update( &accumulator,
buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
TEST_ASSERT( mbedtls_md( md_info, 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;
TEST_ASSERT( mbedtls_md_update( &accumulator, header, 2 ) == 0 );
TEST_ASSERT( mbedtls_md_update( &accumulator,
empty, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
header[0] = 0;
TEST_ASSERT( mbedtls_md_update( &accumulator, header, 2 ) == 0 );
TEST_ASSERT( mbedtls_md_update( &accumulator,
check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
TEST_ASSERT( mbedtls_md_finish( &accumulator, buf ) == 0 );
TEST_ASSERT( mbedtls_md( md_info, 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 );
exit:
mbedtls_md_free( &accumulator );
mbedtls_entropy_free( &ctx );
mbedtls_nv_seed_read = original_mbedtls_nv_seed_read;
mbedtls_nv_seed_write = original_mbedtls_nv_seed_write;
}
/* END_CASE */
/* BEGIN_CASE depends_on:ENTROPY_HAVE_STRONG:MBEDTLS_SELF_TEST */
void entropy_selftest( int result )
{
TEST_ASSERT( mbedtls_entropy_self_test( 1 ) == result );
}
/* END_CASE */