GPSW serialization (#28)

.circleci/config.yml

@@ -19,6 +19,26 @@ jobs:
             python -m pip install --upgrade pip
             pip install cmake
 
+      - run:
+          name: Install Protobuff
+          command: |
+            wget https://github.com/protocolbuffers/protobuf/releases/download/v3.12.2/protobuf-cpp-3.12.2.tar.gz
+            tar xvzf protobuf-cpp-3.12.2.tar.gz --no-same-owner
+            cd protobuf-3.12.2
+            ./configure
+            make
+            make check
+            make install
+            ldconfig
+
+      - run:
+          name: Install Protobuff-c
+          command: |
+            wget https://github.com/protobuf-c/protobuf-c/releases/download/v1.3.3/protobuf-c-1.3.3.tar.gz
+            tar xvzf protobuf-c-1.3.3.tar.gz --no-same-owner
+            cd protobuf-c-1.3.3
+            ./configure && make && make install
+
       - run:
           name: Install AMCL
           command: |

CMakeLists.txt

@@ -68,12 +68,28 @@ set(library_SOURCES
         src/abe/fame.c
         src/abe/dippe.c
         src/quadratic/sgp.c
+        src/serialization/fame_ser.c
+        src/serialization/data_ser.c
+        src/serialization/gpsw_ser.c
+        include/cifer/serialization/fame.pb-c.c
+        include/cifer/serialization/data.pb-c.c
+        include/cifer/serialization/gpsw.pb-c.c
         )
 
 add_library(cifer SHARED ${library_SOURCES})
 
 # Link libraries that are used in our library
 target_link_libraries(cifer gmp sodium m amcl)
+# Search for protobuf-c library
+find_package(PkgConfig)
+if (PKG_CONFIG_FOUND)
+    pkg_check_modules(PBUFC "libprotobuf-c >= 1.0.0")
+    if (PBUFC_FOUND)
+        target_link_libraries(cifer ${PBUFC_LIBRARIES})
+        add_definitions(${PBUFC_CFLAGS} ${PBUFC_CFLAGS_OTHER})
+        link_directories(${PBUFC_LIBRARY_DIRS})
+    endif()
+endif()
 
 # Install library and copy header to install dir
 install(TARGETS cifer DESTINATION lib)
@@ -114,6 +130,9 @@ set(binary_SOURCES
         test/abe/dippe.c
         external/munit/munit.c
         test/quadratic/sgp.c
+        test/serialization/data_ser.c
+        test/serialization/fame_ser.c
+        test/serialization/gpsw_ser.c
         )
 
 add_executable(cifer_test ${binary_SOURCES})

README.md

@@ -544,3 +544,25 @@ cfe_fame_generate_attrib_keys(&keys, owned_attrib, 3, &sk, &fame);
 FP12_BN254 decryption;
 cfe_fame_decrypt(&decryption, &cipher, &keys, &fame);
 ```
+
+##### Serialize ABE material
+
+In the example below we demonstrate how to serialize public key for ABE scheme GPSW.
+The serialization is done by using [Protobuf](https://github.com/protocolbuffers/protobuf)
+library, converting CiFEr structures to a single array of bytes.
+The serialization is currently available for ABE schemes FAME and GPSW.
+```c
+// create GPSW structure
+cfe_gpsw gpsw;
+cfe_gpsw_init(&gpsw, 10);
+
+// create and init GPSW master keys
+cfe_gpsw_pub_key pk;
+cfe_vec sk;
+cfe_gpsw_master_keys_init(&pk, &sk, &gpsw);
+cfe_gpsw_generate_master_keys(&pk, &sk, &gpsw);
+
+// serialize public key into a buffer of bytes
+cfe_ser buf;
+cfe_gpsw_pub_key_ser(&pk, &buf);
+```

include/cifer/data/vec_curve.h

@@ -52,6 +52,14 @@ typedef struct cfe_vec_GT {
     size_t size; /** The size of the vector */
 } cfe_vec_GT;
 
+/**
+ * Vector of octets elements.
+ */
+typedef struct cfe_vec_octet {
+    octet *vec; /** A pointer to the first element */
+    size_t size; /** The size of the vector */
+} cfe_vec_octet;
+
 /**
  * Initializes a vector of ECP_BN254 elements of given size.
  *
@@ -178,4 +186,21 @@ void cfe_vec_G2_free(cfe_vec_G2 *v);
  */
 void cfe_vec_GT_free(cfe_vec_GT *v);
 
+/**
+ * Initializes a vector of octet elements of given size.
+ *
+ * @param v A pointer to an uninitialized cfe_vec_G1 vector
+ * @param size Size of the vector
+ */
+void cfe_vec_octet_init(cfe_vec_octet *v, size_t size);
+
+/**
+ * Frees the memory occupied by the struct members. It does not free
+ * memory occupied by the struct itself.
+ *
+ * @param v A pointer to a vector (*initialized*
+ * cfe_vec_octet struct)
+ */
+void cfe_vec_octet_free(cfe_vec_octet *v);
+
 #endif