diff --git a/configure.ac b/configure.ac index 010072c7..111de09e 100644 --- a/configure.ac +++ b/configure.ac @@ -44,18 +44,19 @@ AC_HEADER_STDBOOL AC_CHECK_HEADERS(errno.h fcntl.h limits.h unistd.h sys/time.h utmp.h \ utmpx.h termios.h termio.h sgtty.h sys/ioctl.h syslog.h paths.h \ - utime.h ulimit.h sys/capability.h sys/resource.h gshadow.h lastlog.h \ - locale.h rpc/key_prot.h netdb.h acl/libacl.h attr/libattr.h \ - attr/error_context.h) + utime.h ulimit.h sys/capability.h sys/random.h sys/resource.h \ + gshadow.h lastlog.h locale.h rpc/key_prot.h netdb.h acl/libacl.h \ + attr/libattr.h attr/error_context.h) dnl shadow now uses the libc's shadow implementation AC_CHECK_HEADER([shadow.h],,[AC_MSG_ERROR([You need a libc with shadow.h])]) -AC_CHECK_FUNCS(l64a fchmod fchown fsync futimes getgroups gethostname getspnam \ - gettimeofday getusershell getutent initgroups lchown lckpwdf lstat \ - lutimes memcpy memset setgroups sigaction strchr updwtmp updwtmpx innetgr \ - getpwnam_r getpwuid_r getgrnam_r getgrgid_r getspnam_r getaddrinfo \ - ruserok dlopen) +AC_CHECK_FUNCS(arc4random_buf l64a fchmod fchown fsync futimes getgroups \ + gethostname getentropy getrandom getspnam gettimeofday getusershell \ + getutent initgroups lchown lckpwdf lstat lutimes memcpy memset \ + setgroups sigaction strchr updwtmp updwtmpx innetgr getpwnam_r \ + getpwuid_r getgrnam_r getgrgid_r getspnam_r getaddrinfo ruserok \ + dlopen) AC_SYS_LARGEFILE dnl Checks for typedefs, structures, and compiler characteristics. diff --git a/libmisc/salt.c b/libmisc/salt.c index af9f011f..13408a53 100644 --- a/libmisc/salt.c +++ b/libmisc/salt.c @@ -15,6 +15,9 @@ #include #include #include +#if HAVE_SYS_RANDOM_H +#include +#endif #include "prototypes.h" #include "defines.h" #include "getdef.h" @@ -128,19 +131,46 @@ static /*@observer@*/char *l64a (long value) static long read_random_bytes (void) { long randval = 0; + +#ifdef HAVE_ARC4RANDOM_BUF + /* arc4random_buf, if it exists, can never fail. */ + arc4random_buf (&randval, sizeof (randval)); + goto end; + +#elif defined(HAVE_GETENTROPY) + /* getentropy may exist but lack kernel support. */ + if (getentropy (&randval, sizeof (randval))) { + goto fail; + } + + goto end; + +#elif defined(HAVE_GETRANDOM) + /* Likewise getrandom. */ + if ((size_t) getrandom (&randval, sizeof (randval), 0) != sizeof (randval)) { + goto fail; + } + + goto end; + +#else FILE *f = fopen ("/dev/urandom", "r"); - if (fread (&randval, sizeof (randval), 1, f) != sizeof (randval)) - { - fprintf (shadow_logfd, - _("Unable to read from /dev/urandom.\n")); - + if (fread (&randval, sizeof (randval), 1, f) != sizeof (randval)) { fclose(f); - exit (1); + goto fail; } fclose(f); + goto end; +#endif +fail: + fprintf (shadow_logfd, + _("Unable to obtain random bytes.\n")); + exit (1); + +end: return randval; }