Dynamically allocate password instead of using VLA

This allows the code to compile with `cl` (MS Windows).

Additionally allows massive passwords to be made more easily I suppose,
as we aren't allocating (potentially dangerously) on the stack anymore.
But, generation may be slightly slower due to allocation of memory. We
could possibly have some statically allocated memory (e.g. 20 bytes) and
if we go over then malloc().

1 files changed, 16 insertions, 1 deletions

diff --git a/passgen.c b/passgen.c
index a21f3ac..bea56fc 100644
--- a/passgen.c
+++ b/passgen.c
@@ -9,6 +9,11 @@
 #include <sys/random.h>
 #else
 #include <time.h>
+#endif
+
+#if defined (_WIN32) && ! defined (__MINGW32__)
+#include <io.h>
+#else
 #include <unistd.h>
 #endif
 
@@ -43,6 +48,10 @@ int main(int argc, char *argv[])
 
     grammar_size = triplets * 3 + specials + numbers;
     grammar = malloc(grammar_size + 1);
+    if (grammar == NULL) {
+      perror("malloc");
+      return 1;
+    }
     grammar[grammar_size] = 0;
 
     memcpy(grammar, "Cvc", 3);
@@ -55,7 +64,11 @@ int main(int argc, char *argv[])
     custom_grammar = true;
   }
 
-  char password[grammar_size+1];
+  char *password = malloc(grammar_size + 1);
+  if (password == NULL) {
+    perror("malloc");
+    return 1;
+  }
   password[grammar_size] = 0;
 
 #ifndef __linux__
@@ -80,6 +93,7 @@ int main(int argc, char *argv[])
       printf("ERROR: Invalid grammar character '%c'.\n", c);
       if (custom_grammar)
         free(grammar);
+      free(password);
       return 1;
     }
 
@@ -98,6 +112,7 @@ int main(int argc, char *argv[])
     free(grammar);
 
   printf("%s\n", password);
+  free(password);
 
   return 0;
 }