Merge remote-tracking branch 'public/pr/2142' into development

This commit is contained in:
Simon Butcher 2018-10-27 18:30:08 +01:00
commit da095619bb
2 changed files with 12 additions and 3 deletions

View File

@ -233,7 +233,9 @@ int mbedtls_ecp_check_budget( const mbedtls_ecp_group *grp,
unsigned ops );
/* Utility macro for checking and updating ops budget */
#define MBEDTLS_ECP_BUDGET( ops ) MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, rs_ctx, ops ) );
#define MBEDTLS_ECP_BUDGET( ops ) \
MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, rs_ctx, \
(unsigned) (ops) ) );
#else /* MBEDTLS_ECP_RESTARTABLE */

View File

@ -248,9 +248,16 @@ int mbedtls_ecp_check_budget( const mbedtls_ecp_group *grp,
else if( grp->pbits >= 384 )
ops *= 2;
/* avoid infinite loops: always allow first step */
if( rs_ctx->ops_done != 0 && rs_ctx->ops_done + ops > ecp_max_ops )
/* Avoid infinite loops: always allow first step.
* Because of that, however, it's not generally true
* that ops_done <= ecp_max_ops, so the check
* ops_done > ecp_max_ops below is mandatory. */
if( ( rs_ctx->ops_done != 0 ) &&
( rs_ctx->ops_done > ecp_max_ops ||
ops > ecp_max_ops - rs_ctx->ops_done ) )
{
return( MBEDTLS_ERR_ECP_IN_PROGRESS );
}
/* update running count */
rs_ctx->ops_done += ops;