| 摘要 |
An Improved CDSA system (CDSA-I) includes a standard CDSA framework coupled via an Application Program Interface to an application requiring cryptographic support. During manufacture, a cryptographic control privilege is incorporated into the application, as part of an exemption mechanism, which exemption may or may not be enforced by the CDSA framework. For maximum cryptographic strength, an application must be signed by a private key controlled by the CDSA framework vendor. Inside the CDSA framework, the corresponding public key is used to verify at runtime those applications that were appropriately signed. The CDSA framework is coupled via a Service Provider Interface (SPI) to a plurality of pluggable modules for performing cryptographic operations, storing signed digital certificates for applications, and trust policies relating to cryptographic strengths. The framework is initialized to provide the cryptographic support for the application. The application requests a a crypto context representing the algorithm ID, key and key length from the CDSA framework at runtime to be used in subsequent API calls to the CDSA framework. The application requests a privilege status and the CDSA framework uses its internal public key at runtime to determine if the application is privileged to perform strong crypto for the current thread using the current crypto context; this is determined by verifying that the application and its credentials were signed by the private key controlled by the CDSA framework vendor. A flag is set in the application if the application will be entitled to strong crypto when the application actually calls the APIs to encrypt data. Otherwise, the flag is not set and it will be stopped from using strong crypto when it calls the APIs to encrypt data.
|
