diff options
| -rw-r--r-- | passgen.c | 74 |
1 files changed, 49 insertions, 25 deletions
@@ -9,26 +9,31 @@ || defined (__APPLE__) \ || defined (__FreeBSD__) \ || defined (__OpenBSD__) -# define USE_GETENTROPY 1 +# define USE_GETENTROPY +#elif defined (_WIN32) && ! defined (__MINGW32__) +# define USE_WINCRYPT #endif + /* getentropy() vs rand()+time()+getpid() */ #ifdef USE_GETENTROPY #if defined (__linux__) || defined (__APPLE__) -# include <sys/random.h> +# include <sys/random.h> #else -# include <unistd.h> +# include <unistd.h> #endif +#elif defined (USE_WINCRYPT) +# define WIN32_LEAN_AND_MEAN +# include <Windows.h> +# include <wincrypt.h> #else -#include <time.h> - -/* getpid() on Windows */ -#if defined (_WIN32) && ! defined (__MINGW32__) -#include <io.h> -#else -#include <unistd.h> -#endif - +# include <time.h> + /* getpid() on Windows */ +# if defined (_WIN32) && ! defined (__MINGW32__) +# include <io.h> +# else +# include <unistd.h> +# endif #endif @@ -39,34 +44,46 @@ break; -void init_rng(void) +#ifdef USE_WINCRYPT +HCRYPTPROV win_rng; +#endif +bool init_rng(void) { - /* For now, this is only needed on rand() */ -#ifndef USE_GETENTROPY +#ifdef USE_WINCRYPT + CryptAcquireContext( + &win_rng, + NULL, + NULL, + PROV_RSA_FULL, + CRYPT_VERIFYCONTEXT | CRYPT_SILENT + ); + if (!win_rng) + return false; +#elif ! defined (USE_GETENTROPY) && ! defined (USE_WINCRYPT) /* * TODO: seed better RNG * this isn't very good, but it's enough(?) for now * - * on linux we use the `getrandom` api which is supposedly - * what crypto uses to generate. potentially on win we - * can use the crypto thing (but it's more complicated - * to invoke). - * - * anything else we could use on posix systems? + * anything else we could use on general posix systems? + * perhaps /dev/urandom is a better fallback before doing this */ srand(time(NULL) + getpid() % 420 - 69); #endif + return true; } unsigned int get_rng(void) { -#ifdef USE_GETENTROPY unsigned int r; +#ifdef USE_GETENTROPY getentropy(&r, sizeof(r)); - return r; +#elif defined (USE_WINCRYPT) + /* TODO: This could fail. Figure out how to handle */ + CryptGenRandom(win_rng, sizeof(r), (BYTE *) &r); #else - return rand(); + r = rand(); #endif + return r; } char *build_grammar(int triplets, int specials, int numbers) @@ -125,7 +142,11 @@ int main(int argc, char *argv[]) } password[grammar_size] = 0; - init_rng(); + if (!init_rng()) { + fprintf(stderr, "ERROR: Could not initialise RNG."); + err = true; + goto cleanup; + } for (int i = 0; i < grammar_size; ++i) { char c = grammar[i]; @@ -154,6 +175,9 @@ int main(int argc, char *argv[]) printf("%s\n", password); cleanup: +#ifdef USE_WINCRYPT + CryptReleaseContext(win_rng, 0); +#endif if (custom_grammar) free(grammar); if (password) |