Fix/configurable storage paths (#55)

* when writing files, create directories if they do not exist

* revert botched merge file

* modify tasks to include debug shared lib builds

* use FILENAME_MAX from stdio instead of PATH_MAX from linux/limits

* include header guard

* Fix windows support for mkdir

Author: AddressXception

.vscode/c_cpp_properties.json

@@ -1,5 +1,16 @@
 {
     "configurations": [
+        {
+            "name": "Linux",
+            "includePath": [
+                "${workspaceFolder}/**"
+            ],
+            "defines": [],
+            "compilerPath": "/usr/bin/gcc",
+            "cStandard": "c11",
+            "cppStandard": "c++17",
+            "intelliSenseMode": "clang-x64"
+        },
         {
             "name": "Mac",
             "includePath": [
@@ -8,13 +19,38 @@
             "defines": [],
             "macFrameworkPath": [
                 "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks",
-                "/System/Library/Frameworks", 
+                "/System/Library/Frameworks",
                 "/Library/Frameworks"
             ],
             "compilerPath": "/usr/bin/clang",
             "cStandard": "c11",
             "cppStandard": "c++17",
             "intelliSenseMode": "${default}"
+        },
+        {
+            "name": "Win64",
+            "includePath": [
+                "${workspaceFolder}/**",
+                "C:\\msys64\\mingw64\\include"
+            ],
+            "defines": [
+                "_DEBUG",
+                "UNICODE",
+                "_UNICODE"
+            ],
+            "windowsSdkVersion": "10.0.18362.0",
+            "compilerPath": "C:\\msys64\\mingw64\\bin\\gcc.exe",
+            "cStandard": "c11",
+            "cppStandard": "c++17",
+            "intelliSenseMode": "gcc-x64",
+            "browse": {
+                "path": [
+                    "C:\\msys64\\mingw64\\include"
+                ],
+                "limitSymbolsToIncludedHeaders": true,
+                "databaseFilename": ""
+            },
+            "forcedInclude": []
         }
     ],
     "version": 4

.vscode/tasks.json

@@ -79,6 +79,35 @@
                 }
             }
         },
+        {
+            "label": "Build Shared Library (debug)",
+            "type": "shell",
+            "command": "cmake",
+            "group": "build",
+            "dependsOn": [ "CMake Build (debug)"],
+            "presentation": {
+                "echo": true,
+                "reveal": "always",
+                "focus": false,
+                "panel": "shared"
+            },
+            "args": ["--build", "build"],
+            "problemMatcher": {
+                "owner": "cpp",
+                "fileLocation": [
+                    "relative",
+                    "${workspaceRoot}"
+                ],
+                "pattern": {
+                    "regexp": "^(.*):(\\d+):(\\d+):\\s+(warning|error):\\s+(.*)$",
+                    "file": 1,
+                    "line": 2,
+                    "column": 3,
+                    "severity": 4,
+                    "message": 5
+                }
+            }
+        },
         {
             "label": "Build Shared Library (release)",
             "type": "shell",

CMakeLists.txt

@@ -63,6 +63,8 @@ add_library(electionguard
     ${PROJECT_SOURCE_DIR}/src/electionguard/random_source.c
     ${PROJECT_SOURCE_DIR}/src/electionguard/trustee_state_rep.h
     ${PROJECT_SOURCE_DIR}/src/electionguard/file.c
+    ${PROJECT_SOURCE_DIR}/src/electionguard/directory.c
+    ${PROJECT_SOURCE_DIR}/src/electionguard/directory.h
     ${PROJECT_SOURCE_DIR}/include/electionguard/api/config.h
     ${PROJECT_SOURCE_DIR}/include/electionguard/api/create_election.h
     ${PROJECT_SOURCE_DIR}/include/electionguard/api/encrypt_ballot.h

examples/api/main.c

@@ -131,7 +131,7 @@ int main()
     if (ok)
     {
         // Assigning an output_path fails if this folder doesn't already exist
-        char *output_path = "../"; // This outputs to the directy above the cwd.
+        char *output_path = "./ballots/"; // This outputs to the directy above the cwd.
         char *output_prefix = "ballots-";
         ok = API_RecordBallots(config.num_selections, current_cast_index, current_spoiled_index,
                 NUM_RANDOM_BALLOT_SELECTIONS, casted_ballot_ids, spoiled_ballot_ids, encrypted_ballots,
@@ -162,7 +162,7 @@ int main()
     uint32_t tally_results[config.num_selections];
     if (ok)
     {
-        char *output_path = "../"; // This outputs to the directy above the cwd.
+        char *output_path = "./tallies/"; // This outputs to the directy above the cwd.
         char *output_prefix = "tally-";
         ok = API_TallyVotes(config, trustee_states, DECRYPTING_TRUSTEES,
                 ballots_filename, output_path, output_prefix, &tally_filename, tally_results);

src/electionguard/api/record_ballots.c

@@ -6,6 +6,7 @@
 #include "api/filename.h"
 #include "serialize/voting.h"
 #include "voting/num_ballots.h"
+#include "directory.h"
 
 static bool initialize_coordinator(uint32_t num_selections);
 static bool get_serialized_ballot_identifier(int64_t ballot_id, struct ballot_identifier *ballot_identifier);
@@ -206,6 +207,10 @@ bool export_ballots(char *export_path, char *filename_prefix, char **output_file
     printf("API_RecordBallots :: generated unique filename for export at \"%s\"\n", *output_filename);
 #endif
 
+    if (ok) {
+        ok = create_directory(export_path);
+    }
+
     if (ok)
     {
         FILE *out = fopen(*output_filename, "w+");

src/electionguard/api/tally_votes.c

@@ -5,6 +5,7 @@
 
 #include "api/base_hash.h"
 #include "api/filename.h"
+#include "directory.h"
 
 // Initialize
 static bool initialize_coordinator(void);
@@ -267,6 +268,10 @@ bool export_tally_votes(char *export_path, char *filename_prefix,
     printf("API_TALLYVOTES :: generated unique filename for export at \"%s\"\n", *output_filename);
 #endif
 
+    if (ok) {
+        ok = create_directory(export_path);
+    }
+
     if (ok)
     {
         FILE *out = fopen(*output_filename, "w+");

src/electionguard/directory.c

@@ -0,0 +1,70 @@
+
+
+#include <stdio.h>     /* FILENAME_MAX */
+#include <sys/stat.h>   /* mkdir(2) */
+#include <errno.h>
+
+#include "directory.h"
+
+#ifndef FILENAME_MAX
+#define FILENAME_MAX=256
+#endif
+
+bool create_directory(const char *path)
+{
+    /* Adapted from http://stackoverflow.com/a/2336245/119527 */
+    const size_t len = strlen(path);
+    char _path[FILENAME_MAX];
+    char *p; 
+
+    errno = 0;
+
+    /* Copy string so its mutable */
+    if (len > sizeof(_path)-1) {
+        errno = ENAMETOOLONG;
+        return false; 
+    }   
+    strcpy(_path, path);
+
+    char *directory_separator;
+#ifdef _WIN32
+        directory_separator = "\\";
+#else
+        directory_separator = "/";
+#endif
+
+    /* Iterate the string */
+    for (p = _path + 1; *p; p++) {
+        if (*p == directory_separator[0]) {
+            /* Temporarily truncate */
+            *p = '\0';
+
+            int mk_dir_res = -1;
+#ifdef _WIN32
+            mk_dir_res = mkdir(_path);
+#else
+            mk_dir_res = mkdir(_path, S_IRWXU);
+#endif
+            if (mk_dir_res != 0) {
+                if (errno != EEXIST)
+                    return false; 
+            }
+
+            *p = directory_separator[0];
+        }
+    }   
+
+    int mk_dir_res = -1;
+#ifdef _WIN32
+    mk_dir_res = mkdir(_path);
+#else
+    mk_dir_res = mkdir(_path, S_IRWXU);
+#endif
+
+    if (mk_dir_res != 0) {
+        if (errno != EEXIST)
+            return false; 
+    }   
+
+    return true;
+}

src/electionguard/directory.h

@@ -0,0 +1,9 @@
+#ifndef __DIRECTORY_H__
+#define __DIRECTORY_H__
+
+#include <stdbool.h>
+#include <string.h>
+
+bool create_directory(const char *path);
+
+#endif /* __DIRECTORY_H__ */

src/electionguard/voting/encrypter.c

@@ -182,6 +182,7 @@ Voting_Encrypter_encrypt_ballot(Voting_Encrypter encrypter,
 
     struct Voting_Encrypter_encrypt_ballot_r balotR;
     balotR.status = VOTING_ENCRYPTER_SUCCESS;
+
     // validate selection
     if (!Validate_selections(selections, encrypter->num_selections, expected_num_selected))
         balotR.status = VOTING_ENCRYPTER_SELECTION_ERROR;