Implement actual cryptographic functions using Crypto++ library

CMakeLists.txt

@@ -45,6 +45,41 @@ else()
     endif()
 endif()
 
+# Handle Crypto++ dependency
+# First try to find it as a package
+find_package(PkgConfig QUIET)
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(CRYPTOPP QUIET libcrypto++ cryptopp)
+endif()
+
+if(CRYPTOPP_FOUND)
+    # Use the found package
+    message(STATUS "Found Crypto++ package")
+    set(CRYPTOPP_INCLUDE_DIRS ${CRYPTOPP_INCLUDE_DIRS})
+    set(CRYPTOPP_LIBRARIES ${CRYPTOPP_LIBRARIES})
+else()
+    # Download it as a submodule or include it directly
+    message(STATUS "Crypto++ not found as package, will use submodule")
+    
+    # Check if we have it in external/cryptopp
+    if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/external/cryptopp/cryptlib.h")
+        set(CRYPTOPP_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/external/cryptopp")
+        # For local build, we assume the library is built separately
+        set(CRYPTOPP_LIBRARIES cryptopp)
+    else()
+        # Try to download it
+        include(FetchContent)
+        FetchContent_Declare(
+            cryptopp
+            GIT_REPOSITORY https://github.com/weidai11/cryptopp.git
+            GIT_TAG CRYPTOPP_8_8_0
+        )
+        FetchContent_MakeAvailable(cryptopp)
+        set(CRYPTOPP_INCLUDE_DIRS ${cryptopp_SOURCE_DIR})
+        set(CRYPTOPP_LIBRARIES cryptopp)
+    endif()
+endif()
+
 # Add library sources
 set(SOURCES
     src/privatebinapi.cpp
@@ -77,6 +112,10 @@ else()
     target_include_directories(privatebinapi PRIVATE ${NLOHMANN_JSON_INCLUDE_DIRS})
 endif()
 
+# Include Crypto++
+target_include_directories(privatebinapi PRIVATE ${CRYPTOPP_INCLUDE_DIRS})
+target_link_libraries(privatebinapi ${CRYPTOPP_LIBRARIES})
+
 # Link dependencies
 target_link_libraries(privatebinapi ${PLATFORM_LIBS})