Move csrand() to a new file csrand.c

A set of APIs similar to arc4random(3) is complex enough to deserve its
own file.

Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Cristian Rodríguez <crrodriguez@opensuse.org>
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Björn Esser <besser82@fedoraproject.org>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Joseph Myers <joseph@codesourcery.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

diff --git a/lib/prototypes.h b/lib/prototypes.h
index 49e3db53ff410e42786604ca4560cc21315f82d7..3a04faa8b1bf34ba9ed80bbff326e0eadfc6cffa 100644 (file)
--- a/lib/prototypes.h
+++ b/lib/prototypes.h
@@ -356,6 +356,9 @@ extern /*@dependent@*/ /*@null@*/struct commonio_entry *__pw_get_head (void);
 extern /*@null@*/ /*@only@*/struct passwd *__pw_dup (const struct passwd *pwent);
 extern void pw_free (/*@out@*/ /*@only@*/struct passwd *pwent);
 
+/* csrand.c */
+unsigned long csrand (void);
+
 /* remove_tree.c */
 extern int remove_tree (const char *root, bool remove_root);
 

diff --git a/libmisc/Makefile.am b/libmisc/Makefile.am
index c2277a02343e34820d6ff68f3a1ad2dee20ff14e..b4ca708d7ae05eb50c9aedeebca65b538f6377b6 100644 (file)
--- a/libmisc/Makefile.am
+++ b/libmisc/Makefile.am
@@ -52,6 +52,7 @@ libmisc_la_SOURCES = \
        pwd2spwd.c \
        pwdcheck.c \
        pwd_init.c \
+       csrand.c \
        remove_tree.c \
        rlogin.c \
        root_flag.c \

diff --git a/libmisc/csrand.c b/libmisc/csrand.c
new file mode 100644 (file)
index 0000000..a023785
--- /dev/null
+++ b/libmisc/csrand.c
@@ -0,0 +1,61 @@
+#include <config.h>
+
+#ident "$Id$"
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#if HAVE_SYS_RANDOM_H
+#include <sys/random.h>
+#endif
+#include "bit.h"
+#include "prototypes.h"
+#include "shadowlog.h"
+
+
+/*
+ * Return a uniformly-distributed CS random u_long value.
+ */
+unsigned long
+csrand(void)
+{
+       FILE           *fp;
+       unsigned long  r;
+
+#ifdef HAVE_GETENTROPY
+       /* getentropy may exist but lack kernel support.  */
+       if (getentropy(&r, sizeof(r)) == 0)
+               return r;
+#endif
+
+#ifdef HAVE_GETRANDOM
+       /* Likewise getrandom.  */
+       if (getrandom(&r, sizeof(r), 0) == sizeof(r))
+               return r;
+#endif
+
+#ifdef HAVE_ARC4RANDOM_BUF
+       /* arc4random_buf can never fail.  */
+       arc4random_buf(&r, sizeof(r));
+       return r;
+#endif
+
+       /* Use /dev/urandom as a last resort.  */
+       fp = fopen("/dev/urandom", "r");
+       if (NULL == fp) {
+               goto fail;
+       }
+
+       if (fread(&r, sizeof(r), 1, fp) != 1) {
+               fclose(fp);
+               goto fail;
+       }
+
+       fclose(fp);
+       return r;
+
+fail:
+       fprintf(log_get_logfd(), _("Unable to obtain random bytes.\n"));
+       exit(1);
+}

diff --git a/libmisc/salt.c b/libmisc/salt.c
index 90ff702fbe9179df55ea83f4237eee680c15310d..c3f3d23a6c24f5bf55aa04c2c3d0506c3a3da071 100644 (file)
--- a/libmisc/salt.c
+++ b/libmisc/salt.c
@@ -20,9 +20,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#if HAVE_SYS_RANDOM_H
-#include <sys/random.h>
-#endif
 #include "prototypes.h"
 #include "defines.h"
 #include "getdef.h"
@@ -89,7 +86,6 @@
 #define GENSALT_SETTING_SIZE 100
 
 /* local function prototypes */
-static long csrand (void);
 #if !USE_XCRYPT_GENSALT
 static /*@observer@*/const char *gensalt (size_t salt_size);
 #endif /* !USE_XCRYPT_GENSALT */
@@ -109,53 +105,6 @@ static /*@observer@*/unsigned long YESCRYPT_get_salt_cost (/*@null@*/const int *
 static /*@observer@*/void YESCRYPT_salt_cost_to_buf (char *buf, unsigned long cost);
 #endif /* USE_YESCRYPT */
 
-/* Read sizeof (long) random bytes from /dev/urandom. */
-static long csrand (void)
-{
-       long randval = 0;
-
-#ifdef HAVE_GETENTROPY
-       /* getentropy may exist but lack kernel support.  */
-       if (getentropy (&randval, sizeof (randval)) == 0) {
-               goto end;
-       }
-#endif
-
-#ifdef HAVE_GETRANDOM
-       /* Likewise getrandom.  */
-       if ((size_t) getrandom (&randval, sizeof (randval), 0) == sizeof (randval)) {
-               goto end;
-       }
-#endif
-
-#ifdef HAVE_ARC4RANDOM_BUF
-       /* arc4random_buf, if it exists, can never fail.  */
-       arc4random_buf (&randval, sizeof (randval));
-       goto end;
-#endif
-
-       /* Use /dev/urandom as a last resort.  */
-       FILE *f = fopen ("/dev/urandom", "r");
-       if (NULL == f) {
-               goto fail;
-       }
-
-       if (fread (&randval, sizeof (randval), 1, f) != 1) {
-               fclose(f);
-               goto fail;
-       }
-
-       fclose(f);
-       goto end;
-
-fail:
-       fprintf (log_get_logfd(),
-                _("Unable to obtain random bytes.\n"));
-       exit (1);
-
-end:
-       return randval;
-}
 
 #if defined(USE_SHA_CRYPT) || defined(USE_BCRYPT)
 /*