tests/suites/test_suite_entropy.function - mirror/mbed-tls.git - TrustedFirmware Git Browser

 /* 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 */
 void entropy_init_free( int reinit )
 {
     mbedtls_entropy_context ctx;

     /* Double free is not explicitly documented to work, but it is convenient
      * to call mbedtls_entropy_free() unconditionally on an error path without
      * checking whether it has already been called in the success path. */

     mbedtls_entropy_init( &ctx );
     mbedtls_entropy_free( &ctx );

     if( reinit )
         mbedtls_entropy_init( &ctx );
     mbedtls_entropy_free( &ctx );

     /* This test case always succeeds, functionally speaking. A plausible
      * bug might trigger an invalid pointer dereference or a memory leak. */
     goto exit;
 }
 /* END_CASE */

 /* 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 depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
 void entropy_write_base_seed_file( int ret )
 {
     mbedtls_entropy_context ctx;

     mbedtls_entropy_init( &ctx );

     TEST_ASSERT( mbedtls_entropy_write_seed_file( &ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE ) == ret );
     TEST_ASSERT( mbedtls_entropy_update_seed_file( &ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE ) == 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 */
	/* 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 */
	void entropy_init_free( int reinit )
	{
	mbedtls_entropy_context ctx;

	/* Double free is not explicitly documented to work, but it is convenient
	* to call mbedtls_entropy_free() unconditionally on an error path without
	* checking whether it has already been called in the success path. */

	mbedtls_entropy_init( &ctx );
	mbedtls_entropy_free( &ctx );

	if( reinit )
	mbedtls_entropy_init( &ctx );
	mbedtls_entropy_free( &ctx );

	/* This test case always succeeds, functionally speaking. A plausible
	* bug might trigger an invalid pointer dereference or a memory leak. */
	goto exit;
	}
	/* END_CASE */

	/* 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 depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
	void entropy_write_base_seed_file( int ret )
	{
	mbedtls_entropy_context ctx;

	mbedtls_entropy_init( &ctx );

	TEST_ASSERT( mbedtls_entropy_write_seed_file( &ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE ) == ret );
	TEST_ASSERT( mbedtls_entropy_update_seed_file( &ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE ) == 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 */