[#143] Fix segfault for missing home directory

doc/man/pgagroal-admin.1.rst

@@ -46,7 +46,7 @@ COMMANDS
 ========
 
 master-key
-  Create or update the master key
+  Create or update the master key. The master key will be created in the pgagroal user home directory under ~/.pgagroal
 
 add-user
   Add a user

src/admin.c

@@ -285,6 +285,22 @@ master_key(char* password, bool generate_pwd, int pwd_length)
    struct stat st = {0};
    bool do_free = true;
 
+   if (pgagroal_get_home_directory() == NULL)
+   {
+      char* username = pgagroal_get_user_name();
+
+      if (username != NULL)
+      {
+         printf("No home directory for user \'%s\'\n", username);
+      }
+      else
+      {
+         printf("No home directory for user running pgagroal\n");
+      }
+
+      goto error;
+   }
+
    memset(&buf, 0, sizeof(buf));
    snprintf(&buf[0], sizeof(buf), "%s/.pgagroal", pgagroal_get_home_directory());
 

src/include/utils.h

@@ -209,6 +209,13 @@ pgagroal_libev_engine(unsigned int val);
 char*
 pgagroal_get_home_directory(void);
 
+/**
+ * Get the user name
+ * @return The user name
+ */
+char*
+pgagroal_get_user_name(void);
+
 /**
  * Get a password from stdin
  * @return The password

src/libpgagroal/utils.c

@@ -557,9 +557,27 @@ pgagroal_get_home_directory(void)
 {
    struct passwd *pw = getpwuid(getuid());
 
+   if (pw == NULL)
+   {
+      return NULL;
+   }
+
    return pw->pw_dir;
 }
 
+char*
+pgagroal_get_user_name(void)
+{
+   struct passwd *pw = getpwuid(getuid());
+
+   if (pw == NULL)
+   {
+      return NULL;
+   }
+
+   return pw->pw_name;
+}
+
 char*
 pgagroal_get_password(void)
 {