implemented configurable checksum algorithm, defaults to sha256, introduces openssl dependency to build module

data/security.conf

@@ -0,0 +1,2 @@
+[cryptography]
+checksum_algorithm=sha256

modules/build/CMakeLists.txt

@@ -10,6 +10,9 @@ else()
     set(DPM_ROOT_DIR "${CMAKE_SOURCE_DIR}")
 endif()
 
+# Find OpenSSL
+find_package(OpenSSL REQUIRED)
+
 # Module version - used by DPM
 add_library(build MODULE
         build.cpp
@@ -17,6 +20,7 @@ add_library(build MODULE
         src/cli_parsers.cpp
         src/commands.cpp
         src/package_staging.cpp
+        src/checksums.cpp
 )
 
 # Set output properties
@@ -30,10 +34,11 @@ set_target_properties(
 target_include_directories(build PRIVATE
         ${CMAKE_CURRENT_SOURCE_DIR}/include
         ${DPM_ROOT_DIR}
+        ${OPENSSL_INCLUDE_DIR}
 )
 
-# Link with filesystem library
-target_link_libraries(build stdc++fs)
+# Link with filesystem library and OpenSSL
+target_link_libraries(build stdc++fs ${OPENSSL_LIBRARIES})
 
 # Standalone version - used for debugging
 add_executable(build_standalone
@@ -42,6 +47,7 @@ add_executable(build_standalone
         src/cli_parsers.cpp
         src/commands.cpp
         src/package_staging.cpp
+        src/checksums.cpp
 )
 
 # Define the BUILD_STANDALONE macro for the standalone build
@@ -51,10 +57,11 @@ target_compile_definitions(build_standalone PRIVATE BUILD_STANDALONE)
 target_include_directories(build_standalone PRIVATE
         ${CMAKE_CURRENT_SOURCE_DIR}/include
         ${DPM_ROOT_DIR}
+        ${OPENSSL_INCLUDE_DIR}
 )
 
-# Link with filesystem library for standalone
-target_link_libraries(build_standalone stdc++fs)
+# Link with filesystem library and OpenSSL for standalone
+target_link_libraries(build_standalone stdc++fs ${OPENSSL_LIBRARIES})
 
 # Set the output name for the standalone executable
 set_target_properties(

modules/build/include/checksums.hpp

@@ -0,0 +1,48 @@
+/**
+* @file checksums.hpp
+ * @brief Functions for generating cryptographic checksums
+ *
+ * Provides functionality for generating checksums of files using
+ * configurable cryptographic hash algorithms via OpenSSL.
+ *
+ * @copyright Copyright (c) 2025 SILO GROUP LLC
+ * @author Chris Punches <chris.punches@silogroup.org>
+ *
+ * Part of the Dark Horse Linux Package Manager (DPM)
+ */
+#pragma once
+
+#include <string>
+#include <filesystem>
+
+/**
+ * @brief Gets the configured hash algorithm or defaults to SHA-256
+ *
+ * Retrieves the hash algorithm configured in the cryptography section
+ * or defaults to SHA-256 if not specified.
+ *
+ * @return String containing the name of the hash algorithm to use
+ */
+std::string get_configured_hash_algorithm();
+
+/**
+ * @brief Gets a list of available digest algorithms from OpenSSL
+ *
+ * Retrieves a list of supported digest algorithms from OpenSSL's
+ * internal algorithms list.
+ *
+ * @return String containing comma-separated list of available algorithms
+ */
+std::string get_available_algorithms();
+
+/**
+ * @brief Generates a file checksum using the configured hashing algorithm
+ *
+ * Uses OpenSSL to calculate a cryptographic hash of a file's contents
+ * based on the algorithm specified in the configuration.
+ * This method reads the file in chunks to handle large files efficiently.
+ *
+ * @param file_path Path to the file to be hashed
+ * @return String containing the hexadecimal representation of the checksum, or empty string on error
+ */
+std::string generate_file_checksum(const std::filesystem::path& file_path);

modules/build/include/package_staging.hpp

@@ -19,6 +19,7 @@
 #include <dpmdk/include/CommonModuleAPI.hpp>
 #include <pwd.h>
 #include <grp.h>
+#include "checksums.hpp"
 
 /**
  * @brief Stages a DPM package

modules/build/src/checksums.cpp

@@ -0,0 +1,139 @@
+/**
+ * @file checksums.cpp
+ * @brief Implementation of cryptographic checksum functions
+ *
+ * Implements functionality for generating checksums of files using
+ * configurable cryptographic hash algorithms via OpenSSL.
+ *
+ * @copyright Copyright (c) 2025 SILO GROUP LLC
+ * @author Chris Punches <chris.punches@silogroup.org>
+ *
+ * Part of the Dark Horse Linux Package Manager (DPM)
+ */
+
+#include "checksums.hpp"
+#include <openssl/evp.h>
+#include <openssl/objects.h>
+#include <fstream>
+#include <sstream>
+#include <iomanip>
+#include <dpmdk/include/CommonModuleAPI.hpp>
+
+std::string get_configured_hash_algorithm()
+{
+    const char* algorithm = dpm_get_config("cryptography", "checksum_algorithm");
+    if (algorithm) {
+        return std::string(algorithm);
+    }
+    return "sha256"; // Default to SHA-256
+}
+
+std::string get_available_algorithms()
+{
+    std::stringstream algorithms;
+
+    // The OBJ_NAME_do_all_sorted will call the supplied callback function
+    // for each algorithm
+    struct AlgorithmCollector {
+        static void callback(const OBJ_NAME* obj, void* arg) {
+            if (obj->type == OBJ_NAME_TYPE_MD_METH) {
+                std::stringstream* ss = static_cast<std::stringstream*>(arg);
+                if (!ss->str().empty()) {
+                    *ss << ", ";
+                }
+                *ss << obj->name;
+            }
+        }
+    };
+
+    // Initialize OpenSSL objects
+    OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);
+
+    // Collect all digest algorithm names
+    OBJ_NAME_do_all_sorted(OBJ_NAME_TYPE_MD_METH,
+                         reinterpret_cast<void (*)(const OBJ_NAME*, void*)>(AlgorithmCollector::callback),
+                         &algorithms);
+
+    return algorithms.str();
+}
+
+std::string generate_file_checksum(const std::filesystem::path& file_path)
+{
+    // Get configured algorithm
+    std::string algorithm_name = get_configured_hash_algorithm();
+    dpm_log(LOG_DEBUG, ("Using hash algorithm: " + algorithm_name).c_str());
+
+    // Initialize OpenSSL EVP context
+    EVP_MD_CTX* mdctx = EVP_MD_CTX_new();
+    if (!mdctx) {
+        dpm_log(LOG_ERROR, "Failed to create OpenSSL EVP context");
+        return "";
+    }
+
+    // Let OpenSSL look up the algorithm by name
+    const EVP_MD* md = EVP_get_digestbyname(algorithm_name.c_str());
+    if (!md) {
+        std::string available_algorithms = get_available_algorithms();
+        std::string error_msg = "Hash algorithm not supported by OpenSSL: " + algorithm_name +
+                     ". Please check your cryptography.checksum_algorithm configuration.\n" +
+                     "Available algorithms: " + available_algorithms;
+        dpm_log(LOG_FATAL, error_msg.c_str());
+        EVP_MD_CTX_free(mdctx);
+        return "";
+    }
+
+    if (EVP_DigestInit_ex(mdctx, md, nullptr) != 1) {
+        dpm_log(LOG_ERROR, "Failed to initialize digest context");
+        EVP_MD_CTX_free(mdctx);
+        return "";
+    }
+
+    // Open the file for reading in binary mode
+    std::ifstream file(file_path, std::ios::binary);
+    if (!file) {
+        dpm_log(LOG_ERROR, ("Failed to open file for checksum: " + file_path.string()).c_str());
+        EVP_MD_CTX_free(mdctx);
+        return "";
+    }
+
+    // Buffer for reading file chunks
+    const size_t buffer_size = 8192;  // 8KB chunks
+    unsigned char buffer[buffer_size];
+
+    // Read and update digest
+    while (file) {
+        file.read(reinterpret_cast<char*>(buffer), buffer_size);
+        size_t bytes_read = file.gcount();
+
+        if (bytes_read > 0) {
+            if (EVP_DigestUpdate(mdctx, buffer, bytes_read) != 1) {
+                dpm_log(LOG_ERROR, "Failed to update digest");
+                EVP_MD_CTX_free(mdctx);
+                file.close();
+                return "";
+            }
+        }
+    }
+
+    file.close();
+
+    // Finalize the digest
+    unsigned char hash[EVP_MAX_MD_SIZE];
+    unsigned int hash_len = 0;
+
+    if (EVP_DigestFinal_ex(mdctx, hash, &hash_len) != 1) {
+        dpm_log(LOG_ERROR, "Failed to finalize digest");
+        EVP_MD_CTX_free(mdctx);
+        return "";
+    }
+
+    EVP_MD_CTX_free(mdctx);
+
+    // Convert binary hash to hexadecimal string
+    std::stringstream ss;
+    for (unsigned int i = 0; i < hash_len; i++) {
+        ss << std::hex << std::setw(2) << std::setfill('0') << static_cast<int>(hash[i]);
+    }
+
+    return ss.str();
+}

modules/build/src/package_staging.cpp

@@ -345,6 +345,10 @@ static bool update_contents_manifest(const std::filesystem::path& package_dir)
         std::filesystem::path contents_dir = package_dir / "contents";
         std::filesystem::path manifest_path = package_dir / "metadata" / "CONTENTS_MANIFEST_DIGEST";
 
+        // Log which hash algorithm is being used
+        std::string hash_algorithm = get_configured_hash_algorithm();
+        dpm_log(LOG_INFO, ("Generating contents manifest using " + hash_algorithm + " checksums...").c_str());
+
         // Open manifest file for writing
         std::ofstream manifest_file(manifest_path);
         if (!manifest_file.is_open()) {
@@ -352,8 +356,6 @@ static bool update_contents_manifest(const std::filesystem::path& package_dir)
             return false;
         }
 
-        dpm_log(LOG_INFO, "Generating contents manifest...");
-
         // Process each file in the contents directory recursively
         for (const auto& entry : std::filesystem::recursive_directory_iterator(contents_dir)) {
             // Skip directories, we only need to record files
@@ -369,8 +371,8 @@ static bool update_contents_manifest(const std::filesystem::path& package_dir)
             // Get file stats for permissions
             struct stat file_stat;
             if (stat(file_path.c_str(), &file_stat) != 0) {
-                dpm_log(LOG_ERROR, ("Failed to get file stats for: " + file_path.string()).c_str());
-                continue;
+                dpm_log(LOG_FATAL, ("Failed to get file stats for: " + file_path.string()).c_str());
+                return false;
             }
 
             // Format permissions as octal
@@ -397,8 +399,12 @@ static bool update_contents_manifest(const std::filesystem::path& package_dir)
 
             std::string ownership = owner + ":" + group;
 
-            // Calculate file checksum (placeholder - would normally use SHA-256)
-            std::string checksum = "CHECKSUM_PLACEHOLDER";  // Actual hash calculation would be here
+            // Calculate file checksum using the configured algorithm
+            std::string checksum = generate_file_checksum(file_path);
+            if (checksum.empty()) {
+                dpm_log(LOG_FATAL, ("Failed to generate checksum for: " + file_path.string()).c_str());
+                return false;
+            }
 
             // By default, mark all files as controlled ('C')
             char control_designation = 'C';