Entropy tests: support multiple dummy sources

Always pass a context object to entropy_dummy_source. This lets us
write tests that register more than one source and keep track of how
many times each one is called.
This commit is contained in:
Gilles Peskine 2019-10-08 14:37:27 +02:00
parent c34b839d85
commit ed04a676ee

View file

@ -3,10 +3,19 @@
#include "mbedtls/entropy_poll.h"
#include "string.h"
/*
* Number of calls made to entropy_dummy_source()
*/
static size_t entropy_dummy_calls;
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
@ -14,25 +23,25 @@ static size_t entropy_dummy_calls;
* 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,
static int entropy_dummy_source( void *arg, unsigned char *output,
size_t len, size_t *olen )
{
entropy_dummy_calls++;
entropy_dummy_context *context = arg;
++context->calls;
if( data == NULL )
*olen = len;
else
switch( context->instruction )
{
int *d = (int *) data;
if( *d < 0 )
case DUMMY_CONSTANT_LENGTH:
*olen = context->length;
break;
case DUMMY_REQUESTED_LENGTH:
*olen = len;
break;
case DUMMY_FAIL:
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
else
*olen = *d;
}
memset( output, 0x2a, *olen );
return( 0 );
}
@ -144,6 +153,7 @@ 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 );
@ -152,10 +162,10 @@ void entropy_too_many_sources( )
* 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,
(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, NULL,
TEST_ASSERT( mbedtls_entropy_add_source( &ctx, entropy_dummy_source, &dummy,
16, MBEDTLS_ENTROPY_SOURCE_WEAK )
== MBEDTLS_ERR_ENTROPY_MAX_SOURCES );
@ -197,13 +207,13 @@ void entropy_func_len( int len, int ret )
void entropy_source_fail( char * path )
{
mbedtls_entropy_context ctx;
int fail = -1;
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,
&fail, 16,
&dummy, 16,
MBEDTLS_ENTROPY_SOURCE_WEAK )
== 0 );
@ -229,16 +239,16 @@ exit:
void entropy_threshold( int threshold, int chunk_size, int result )
{
mbedtls_entropy_context ctx;
entropy_dummy_context dummy = {DUMMY_CONSTANT_LENGTH, chunk_size, 0};
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,
&dummy, threshold,
MBEDTLS_ENTROPY_SOURCE_WEAK ) == 0 );
entropy_dummy_calls = 0;
ret = mbedtls_entropy_func( &ctx, buf, sizeof( buf ) );
if( result >= 0 )
@ -248,7 +258,7 @@ void entropy_threshold( int threshold, int chunk_size, int result )
// Two times as much calls due to the NV seed update
result *= 2;
#endif
TEST_ASSERT( entropy_dummy_calls == (size_t) result );
TEST_ASSERT( dummy.calls == (size_t) result );
}
else
{