CPPL - Compact Privacy Policy Language

Build Instructions

Preliminaries

Tested with Ubuntu 14.04

sudo apt-get install g++ flex bison libboost-all-dev libjsoncpp-dev

Configuration

See debug.hh and options.hh, e.g., #define DEBUG_POLICY_GENERATION 1 enables output of the policy generation including the compressed policy.

Compiling

make

Usage Examples

./cppl_generator --help

./cppl_generator --input-file examples/example_paper/policy_textual.cppl --policy-definition-file examples/example_paper/policy_definition.json --variables-file examples/example_paper/policy_nodeparams_1.json --runtime-variables-file examples/example_paper/policy_noderuntimeparams_1.json

In real use cases, compression and evaluation take place on different machines. More specifically, compression takes place at the client and evaluation takes place at policy decision points, e.g., routers, load balancers, or cloud servers. The following binaries separate compression and evaluation of a policy:

./cppl_compress --input-file examples/example_paper/policy_textual.cppl --policy-definition-file examples/example_paper/policy_definition.json -o examples/example_paper/policy_compressed.ccppl
./cppl_evaluate --ccppl-file examples/example_paper/policy_compressed.ccppl --policy-definition-file examples/example_paper/policy_definition.json --variables-file examples/example_paper/policy_nodeparams_1.json --runtime-variables-file examples/example_paper/policy_noderuntimeparams_1.json

Furthermore, the server needs to know which parts of the policy it has to apply, i.e., which of his attributes fulfill the formula. To this end, the option --print-reason FILE of cppl_evaluate outputs these attributes as a JSON file.

./cppl_evaluate --ccppl-file examples/example_paper/policy_compressed.ccppl --policy-definition-file examples/example_paper/policy_definition.json --variables-file examples/example_paper/policy_nodeparams_1.json --runtime-variables-file examples/example_paper/policy_noderuntimeparams_1.json --print-reason examples/example_paper/evaluation_result.json

Debugging

The compressed policy is a binary file. To compare it with the readable debugging output it is helpful to print it as a bitstream

xxd -b examples/example_paper/policy_compressed.ccppl