Techniques for permitting access across a context barrier on a small footprint device using an entry point object
First Claim
1. A small footprint device comprising a. at least one processing element;
- b. memory, c. a context barrier for isolating one program module from at least one other program module using said memory and processing element, and d. an entry point object for permitting one program module to access one other program module across said context barrier.
2 Assignments
0 Petitions
Accused Products
Abstract
A small footprint device can securely run multiple programs from unrelated vendors by the inclusion of a context barrier isolating the execution of the programs. The context barrier performs security checks to see that principal and object are within the same namespace or memory space and to see that a requested action is appropriate for an object to be operated upon. Each program or set of programs runs in a separate context. Access from one program to another program across the context barrier can be achieved under controlled circumstances by using an entry point object. The entry point object can either perform accesses across the context barrier on behalf of a requesting program or can pass the request to the program to be accessed and switch contexts to the program to be accessed.
-
Citations
57 Claims
-
1. A small footprint device comprising
a. at least one processing element; -
b. memory, c. a context barrier for isolating one program module from at least one other program module using said memory and processing element, and d. an entry point object for permitting one program module to access one other program module across said context barrier.
-
-
2-29. -29. (canceled)
-
30. A small footprint device comprising:
-
at least one processing element configured to execute groups of one or more program modules in separate contexts, said one or more program modules comprising zero or more sets of executable instructions and zero or more sets of data definitions, said zero or more sets of executable instructions and said zero or more data definitions grouped as object definitions, each context comprising a protected object instance space such that at least one of said object definitions is instantiated in association with a particular context;
a memory comprising instances of objects; and
a context barrier for separating and isolating said contexts, said context barrier configured for controlling execution of at least one instruction of one of said zero or more sets of instructions comprised by a program module based at least in part on whether said at least one instruction is executed for an object instance associated with a first one of said one or more separate contexts and whether said at least one instruction is requesting access to an instance of an object definition associated with a second one of said one or more separate contexts, said context barrier further configured to prevent said access if said access is unauthorized and enable said access if said access is authorized; and
an entry point object for permitting one program module to access information from another program module across said context barrier. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42)
-
-
43. A method of operating a small footprint device that includes a processing machine, wherein program modules are executed on the processing machine, the method comprising:
-
separating contexts using a context barrier, said context barrier configured to for controlling execution of at least one instruction of one of said zero or more sets of instructions comprised by a program module based at least in part on whether said at least one instruction is executed for an object instance associated with a first one of said one or more separate contexts and whether said at least one instruction is requesting access to an instance of an object definition associated with a second one of said one or more separate contexts, said separating further comprising;
preventing said access if said access is unauthorized; and
enabling said access if said access is authorized;
executing groups of one or more program modules in separate contexts, said one or more program modules comprising zero or more sets of executable instructions and zero or more sets of data definitions, said zero or more sets of executable instructions and said zero or more data definitions grouped as object definitions, each context comprising a protected object instance space such that at least one of said object definitions is instantiated in association with a particular context; and
permitting access to information across said context barrier using an entry point object. - View Dependent Claims (44, 45, 46)
-
-
47. A method of permitting access to information on a small footprint device from a first program module to a second program module separated by a context barrier, said small footprint device comprising:
-
at least one processing element configured to execute groups of one or more program modules in separate contexts, said one or more program modules comprising zero or more sets of executable instructions and zero or more sets of data definitions, said zero or more sets of executable instructions and said zero or more data definitions grouped as object definitions, each context comprising a protected object instance space such that at least one of said object definitions is instantiated in association with a particular context;
a memory comprising instances of objects; and
a context barrier for separating and isolating said contexts, said context barrier configured for controlling execution of at least one instruction of one of said zero or more sets of instructions comprised by a program module based at least in part on whether said at least one instruction is executed for an object instance associated with a first one of said one or more separate contexts and whether said at least one instruction is requesting access to an instance of an object definition associated with a second one of said one or more separate contexts, said context barrier further configured to prevent said access if said access is unauthorized and enable said access if said access is authorized, the method comprising;
creating an entry point object which may be accessed by at least two program modules; and
using said entry point object to permit access to information across said context barrier. - View Dependent Claims (48, 49, 50)
-
-
51. A computer program product, comprising:
-
a memory medium; and
a computer controlling element comprising instructions for implementing a context barrier on a small footprint device and for bypassing said context barrier using an entry point object, said small footprint device comprising;
at least one processing element configured to execute groups of one or more program modules in separate contexts, said one or more program modules comprising zero or more sets of executable instructions and zero or more sets of data definitions, said zero or more sets of executable instructions and said zero or more data definitions grouped as object definitions, each context comprising a protected object instance space such that at least one of said object definitions is instantiated in association with a particular context;
a memory comprising instances of objects; and
a context barrier for separating and isolating said contexts, said context barrier configured for controlling execution of at least one instruction of one of said zero or more sets of instructions comprised by a program module based at least in part on whether said at least one instruction is executed for an object instance associated with a first one of said one or more separate contexts and whether said at least one instruction is requesting access to an instance of an object definition associated with a second one of said one or more separate contexts, said context barrier further configured to prevent said access if said access is unauthorized and enable said access if said access is authorized. - View Dependent Claims (52)
-
-
53. A computer program product, comprising:
-
a memory medium; and
a computer controlling element comprising instructions for separating a plurality of programs on a small footprint device by running them in respective contexts and for permitting one program to access information from another program by bypassing a context barrier using an entry point object, said small footprint device comprising;
at least one processing element configured to execute groups of one or more program modules in separate contexts, said one or more program modules comprising zero or more sets of executable instructions and zero or more sets of data definitions, said zero or more sets of executable instructions and said zero or more data definitions grouped as object definitions, each context comprising a protected object instance space such that at least one of said object definitions is instantiated in association with a particular context;
a memory comprising instances of objects; and
a context barrier for separating and isolating said contexts, said context barrier configured for controlling execution of at least one instruction of one of said zero or more sets of instructions comprised by a program module based at least in part on whether said at least one instruction is executed for an object instance associated with a first one of said one or more separate contexts and whether said at least one instruction is requesting access to an instance of an object definition associated with a second one of said one or more separate contexts, said context barrier further configured to prevent said access if said access is unauthorized and enable said access if said access is authorized. - View Dependent Claims (54)
-
-
55. A carrier wave carrying instructions for implementing an entry point object for bypassing a context barrier on a small footprint device over a communications link, said small footprint device comprising:
-
at least one processing element configured to execute groups of one or more program modules in separate contexts, said one or more program modules comprising zero or more sets of executable instructions and zero or more sets of data definitions, said zero or more sets of executable instructions and said zero or more data definitions grouped as object definitions, each context comprising a protected object instance space such that at least one of said object definitions is instantiated in association with a particular context;
a memory comprising instances of objects; and
a context barrier for separating and isolating said contexts, said context barrier configured for controlling execution of at least one instruction of one of said zero or more sets of instructions comprised by a program module based at least in part on whether said at least one instruction is executed for an object instance associated with a first one of said one or more separate contexts and whether said at least one instruction is requesting access to an instance of an object definition associated with a second one of said one or more separate contexts, said context barrier further configured to prevent said access if said access is unauthorized and enable said access if said access is authorized.
-
-
56. A carrier wave carrying instructions over a communications link for separating a plurality of programs on a small footprint device by running them in respective contexts and for permitting one program to access information from another program using at least one entry point object, said small footprint device comprising:
-
at least one processing element configured to execute groups of one or more program modules in separate contexts, said one or more program modules comprising zero or more sets of executable instructions and zero or more sets of data definitions, said zero or more sets of executable instructions and said zero or more data definitions grouped as object definitions, each context comprising a protected object instance space such that at least one of said object definitions is instantiated in association with a particular context;
a memory comprising instances of objects; and
a context barrier for separating and isolating said contexts, said context barrier configured for controlling execution of at least one instruction of one of said zero or more sets of instructions comprised by a program module based at least in part on whether said at least one instruction is executed for an object instance associated with a first one of said one or more separate contexts and whether said at least one instruction is requesting access to an instance of an object definition associated with a second one of said one or more separate contexts, said context barrier further configured to prevent said access if said access is unauthorized and enable said access if said access is authorized.
-
-
57. A method of transmitting code over a network, comprising transmitting a block of code from a server, said block of code comprising instructions for implementing an entry point object for bypassing a context barrier on a small footprint device over a communications link, said small footprint device comprising:
-
at least one processing element configured to execute groups of one or more program modules in separate contexts, said one or more program modules comprising zero or more sets of executable instructions and zero or more sets of data definitions, said zero or more sets of executable instructions and said zero or more data definitions grouped as object definitions, each context comprising a protected object instance space such that at least one of said object definitions is instantiated in association with a particular context;
a memory comprising instances of objects; and
a context barrier for separating and isolating said contexts, said context barrier configured for controlling execution of at least one instruction of one of said zero or more sets of instructions comprised by a program module based at least in part on whether said at least one instruction is executed for an object instance associated with a first one of said one or more separate contexts and whether said at least one instruction is requesting access to an instance of an object definition associated with a second one of said one or more separate contexts, said context barrier further configured to prevent said access if said access is unauthorized and enable said access if said access is authorized.
-
Specification