diffieHellman.verifyError
包含在 DiffieHellman 对象初始化期间执行的检查所产生的任何警告和/或错误的位字段。
以下值对此属性有效（如 constants 模块中所定义）：
DH_CHECK_P_NOT_SAFE_PRIMEDH_CHECK_P_NOT_PRIMEDH_UNABLE_TO_CHECK_GENERATORDH_NOT_SUITABLE_GENERATOR
A bit field containing any warnings and/or errors resulting from a check
performed during initialization of the DiffieHellman object.
The following values are valid for this property (as defined in constants
module):
DH_CHECK_P_NOT_SAFE_PRIMEDH_CHECK_P_NOT_PRIMEDH_UNABLE_TO_CHECK_GENERATORDH_NOT_SUITABLE_GENERATOR