Fix entropy thresholds

This commit is contained in:
Manuel Pégourié-Gonnard 2015-06-19 09:40:51 +02:00
parent 60c793bdc9
commit bf82ff0209
3 changed files with 12 additions and 13 deletions

View File

@ -107,8 +107,8 @@ typedef struct
{ {
mbedtls_entropy_f_source_ptr f_source; /**< The entropy source callback */ mbedtls_entropy_f_source_ptr f_source; /**< The entropy source callback */
void * p_source; /**< The callback data pointer */ void * p_source; /**< The callback data pointer */
size_t size; /**< Amount received */ size_t size; /**< Amount received in bytes */
size_t threshold; /**< Minimum level required before release */ size_t threshold; /**< Minimum bytes required before release */
} }
mbedtls_entropy_source_state; mbedtls_entropy_source_state;
@ -155,7 +155,7 @@ void mbedtls_entropy_free( mbedtls_entropy_context *ctx );
* \param f_source Entropy function * \param f_source Entropy function
* \param p_source Function data * \param p_source Function data
* \param threshold Minimum required from source before entropy is released * \param threshold Minimum required from source before entropy is released
* ( with mbedtls_entropy_func() ) * ( with mbedtls_entropy_func() ) (in bytes)
* *
* \return 0 if successful or MBEDTLS_ERR_ENTROPY_MAX_SOURCES * \return 0 if successful or MBEDTLS_ERR_ENTROPY_MAX_SOURCES
*/ */

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@ -37,11 +37,11 @@ extern "C" {
#endif #endif
/* /*
* Default thresholds for built-in sources * Default thresholds for built-in sources, in bytes
*/ */
#define MBEDTLS_ENTROPY_MIN_PLATFORM 128 /**< Minimum for platform source */ #define MBEDTLS_ENTROPY_MIN_PLATFORM 32 /**< Minimum for platform source */
#define MBEDTLS_ENTROPY_MIN_HAVEGE 128 /**< Minimum for HAVEGE */ #define MBEDTLS_ENTROPY_MIN_HAVEGE 32 /**< Minimum for HAVEGE */
#define MBEDTLS_ENTROPY_MIN_HARDCLOCK 32 /**< Minimum for mbedtls_timing_hardclock() */ #define MBEDTLS_ENTROPY_MIN_HARDCLOCK 4 /**< Minimum for mbedtls_timing_hardclock() */
#if !defined(MBEDTLS_NO_PLATFORM_ENTROPY) #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
/** /**

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@ -250,7 +250,7 @@ int mbedtls_entropy_gather( mbedtls_entropy_context *ctx )
int mbedtls_entropy_func( void *data, unsigned char *output, size_t len ) int mbedtls_entropy_func( void *data, unsigned char *output, size_t len )
{ {
int ret, count = 0, i, reached; int ret, count = 0, i, done;
mbedtls_entropy_context *ctx = (mbedtls_entropy_context *) data; mbedtls_entropy_context *ctx = (mbedtls_entropy_context *) data;
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE]; unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
@ -276,13 +276,12 @@ int mbedtls_entropy_func( void *data, unsigned char *output, size_t len )
if( ( ret = entropy_gather_internal( ctx ) ) != 0 ) if( ( ret = entropy_gather_internal( ctx ) ) != 0 )
goto exit; goto exit;
reached = 0; done = 1;
for( i = 0; i < ctx->source_count; i++ ) for( i = 0; i < ctx->source_count; i++ )
if( ctx->source[i].size >= ctx->source[i].threshold ) if( ctx->source[i].size < ctx->source[i].threshold )
reached++; done = 0;
} }
while( reached != ctx->source_count ); while( ! done );
memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE ); memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );