Prevent memory leak in ecp_check_pubkey_x25519()

Signed-off-by: Janos Follath <janos.follath@arm.com>
This commit is contained in:
Janos Follath 2021-06-24 14:24:13 +01:00
parent 520f0a0ea0
commit b4c676e6b3

View File

@ -2999,18 +2999,30 @@ static int ecp_check_pubkey_x25519( const mbedtls_mpi *X, const mbedtls_mpi *P )
/* Check against the known bad values that are less than P in the
* following list: https://cr.yp.to/ecdh.html#validate */
if( mbedtls_mpi_cmp_int( &XmP, 1 ) <= 0 ) /* takes care of 0 and 1 */
return( MBEDTLS_ERR_ECP_INVALID_KEY );
{
ret = MBEDTLS_ERR_ECP_INVALID_KEY;
goto cleanup;
}
if( mbedtls_mpi_cmp_mpi( &XmP, &ecp_x25519_bad_point_1 ) == 0 )
return( MBEDTLS_ERR_ECP_INVALID_KEY );
{
ret = MBEDTLS_ERR_ECP_INVALID_KEY;
goto cleanup;
}
if( mbedtls_mpi_cmp_mpi( &XmP, &ecp_x25519_bad_point_2 ) == 0 )
return( MBEDTLS_ERR_ECP_INVALID_KEY );
{
ret = MBEDTLS_ERR_ECP_INVALID_KEY;
goto cleanup;
}
/* Final check: check if XmP + 1 is P (final because it changes XmP!) */
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &XmP, &XmP, 1 ) );
if( mbedtls_mpi_cmp_mpi( &XmP, P ) == 0 )
return( MBEDTLS_ERR_ECP_INVALID_KEY );
{
ret = MBEDTLS_ERR_ECP_INVALID_KEY;
goto cleanup;
}
ret = 0;