#define WHITESPACE " \t\n"
+#ifndef RUSAGE_SELF
+# define RUSAGE_SELF 0
+#endif
+#ifndef RUSAGE_CHILDREN
+# define RUSAGE_CHILDREN 0
+#endif
+
#if defined(EGD_SOCKET) || defined(RANDOM_POOL)
#ifdef EGD_SOCKET
/* Collect entropy from EGD */
-void get_random_bytes(unsigned char *buf, int len)
+int get_random_bytes(unsigned char *buf, int len)
{
- static int egd_socket = -1;
- int c;
- char egd_message[2] = { 0x02, 0x00 };
+ int fd;
+ char msg[2];
struct sockaddr_un addr;
int addr_len;
- memset(&addr, '\0', sizeof(addr));
- addr.sun_family = AF_UNIX;
-
- /* FIXME: compile time check? */
+ /* Sanity checks */
if (sizeof(EGD_SOCKET) > sizeof(addr.sun_path))
fatal("Random pool path is too long");
-
+ if (len > 255)
+ fatal("Too many bytes to read from EGD");
+
+ memset(&addr, '\0', sizeof(addr));
+ addr.sun_family = AF_UNIX;
strlcpy(addr.sun_path, EGD_SOCKET, sizeof(addr.sun_path));
-
addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(EGD_SOCKET);
- if (egd_socket == -1) {
- egd_socket = socket(AF_UNIX, SOCK_STREAM, 0);
- if (egd_socket == -1)
- fatal("Couldn't create AF_UNIX socket: %s", strerror(errno));
- if (connect(egd_socket, (struct sockaddr*)&addr, addr_len) == -1)
- fatal("Couldn't connect to EGD socket \"%s\": %s", addr.sun_path, strerror(errno));
- }
+ fd = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (fd == -1) {
+ error("Couldn't create AF_UNIX socket: %s", strerror(errno));
+ return(0);
+ }
+
+ if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) {
+ error("Couldn't connect to EGD socket \"%s\": %s",
+ addr.sun_path, strerror(errno));
+ close(fd);
+ return(0);
+ }
- if (len > 255)
- fatal("Too many bytes to read from EGD");
-
/* Send blocking read request to EGD */
- egd_message[1] = len;
+ msg[0] = 0x02;
+ msg[1] = len;
- c = atomicio(write, egd_socket, egd_message, sizeof(egd_message));
- if (c == -1)
- fatal("Couldn't write to EGD socket \"%s\": %s", EGD_SOCKET, strerror(errno));
+ if (atomicio(write, fd, msg, sizeof(msg)) != sizeof(msg)) {
+ error("Couldn't write to EGD socket \"%s\": %s",
+ EGD_SOCKET, strerror(errno));
+ close(fd);
+ return(0);
+ }
- c = atomicio(read, egd_socket, buf, len);
- if (c <= 0)
- fatal("Couldn't read from EGD socket \"%s\": %s", EGD_SOCKET, strerror(errno));
+ if (atomicio(read, fd, buf, len) != len) {
+ error("Couldn't read from EGD socket \"%s\": %s",
+ EGD_SOCKET, strerror(errno));
+ close(fd);
+ return(0);
+ }
+
+ close(fd);
+
+ return(1);
}
#else /* !EGD_SOCKET */
#ifdef RANDOM_POOL
/* Collect entropy from /dev/urandom or pipe */
-void get_random_bytes(unsigned char *buf, int len)
+int get_random_bytes(unsigned char *buf, int len)
{
- static int random_pool = -1;
- int c;
+ int random_pool;
+ random_pool = open(RANDOM_POOL, O_RDONLY);
if (random_pool == -1) {
- random_pool = open(RANDOM_POOL, O_RDONLY);
- if (random_pool == -1)
- fatal("Couldn't open random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
+ error("Couldn't open random pool \"%s\": %s",
+ RANDOM_POOL, strerror(errno));
+ return(0);
}
- c = atomicio(read, random_pool, buf, len);
- if (c <= 0)
- fatal("Couldn't read from random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
+ if (atomicio(read, random_pool, buf, len) != len) {
+ error("Couldn't read from random pool \"%s\": %s",
+ RANDOM_POOL, strerror(errno));
+ close(random_pool);
+ return(0);
+ }
+
+ close(random_pool);
+
+ return(1);
}
#endif /* RANDOM_POOL */
#endif /* EGD_SOCKET */
char buf[32];
debug("Seeding random number generator");
- get_random_bytes(buf, sizeof(buf));
- RAND_add(buf, sizeof(buf), sizeof(buf));
+
+ if (!get_random_bytes(buf, sizeof(buf))) {
+ if (!RAND_status())
+ fatal("Entropy collection failed and entropy exhausted");
+ } else {
+ RAND_add(buf, sizeof(buf), sizeof(buf));
+ }
+
memset(buf, '\0', sizeof(buf));
}
+/* No-op */
+void init_rng(void) {}
+
#else /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
/*
/* static int entropy_timeout_default = ENTROPY_TIMEOUT_MSEC; */
static int entropy_timeout_current = ENTROPY_TIMEOUT_MSEC;
-static int prng_seed_loaded = 0;
static int prng_seed_saved = 0;
-static int prng_commands_loaded = 0;
+static int prng_initialised = 0;
+uid_t original_uid;
typedef struct
{
total_entropy_estimate = 0;
i = getpid();
- RAND_add(&i, sizeof(i), 0.1);
+ RAND_add(&i, sizeof(i), 0.5);
total_entropy_estimate += 0.1;
i = getppid();
- RAND_add(&i, sizeof(i), 0.1);
+ RAND_add(&i, sizeof(i), 0.5);
total_entropy_estimate += 0.1;
i = getuid();
RAND_add(&i, sizeof(i), 0.0);
total_entropy_estimate += stir_gettimeofday(1.0);
- total_entropy_estimate += stir_clock(0.2);
+ total_entropy_estimate += stir_clock(0.5);
total_entropy_estimate += stir_rusage(RUSAGE_SELF, 2.0);
return(total_entropy_estimate);
struct rusage ru;
if (getrusage(who, &ru) == -1)
- fatal("Couldn't getrusage: %s", strerror(errno));
+ return(0);
- RAND_add(&ru, sizeof(ru), 0.1);
+ RAND_add(&ru, sizeof(ru), entropy_estimate);
return(entropy_estimate);
#else /* _HAVE_GETRUSAGE */
close(p[1]);
close(devnull);
+ setuid(original_uid);
execv(src->path, (char**)(src->args));
debug("(child) Couldn't exec '%s': %s", src->cmdstring,
strerror(errno));
- src->badness = src->sticky_badness = 128;
_exit(-1);
default: /* Parent */
break;
ret = select(p[0]+1, &rdset, NULL, NULL, &tv);
+ RAND_add(&tv, sizeof(tv), 0.0);
+
switch (ret) {
case 0:
/* timer expired */
error_abort = 1;
break;
-
case 1:
/* command input */
bytes_read = read(p[0], buf, sizeof(buf));
+ RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
if (bytes_read == -1) {
error_abort = 1;
break;
- }
- if (bytes_read) {
+ } else if (bytes_read) {
SHA1_Update(&sha, buf, bytes_read);
total_bytes_read += bytes_read;
- RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
- } else
+ } else {
cmd_eof = 1;
-
+ }
break;
-
case -1:
default:
+ /* error */
debug("Command '%s': select() failed: %s", src->cmdstring,
strerror(errno));
error_abort = 1;
break;
- } /* switch ret */
-
- RAND_add(&tv, sizeof(&tv), 0.0);
- } /* while !error_abort && !cmd_eof */
+ }
+ }
SHA1_Final(hash, &sha);
fatal("PRNG seedfile %.100s is not a regular file", filename);
/* mode 0600, owned by root or the current user? */
- if (((st.st_mode & 0177) != 0) || !(st.st_uid == getuid()))
+ if (((st.st_mode & 0177) != 0) || !(st.st_uid == original_uid))
fatal("PRNG seedfile %.100s must be mode 0600, owned by uid %d",
filename, getuid());
if (prng_seed_saved)
return;
+ setuid(original_uid);
+
prng_seed_saved = 1;
- pw = getpwuid(getuid());
+ pw = getpwuid(original_uid);
if (pw == NULL)
fatal("Couldn't get password entry for current user (%i): %s",
- getuid(), strerror(errno));
+ original_uid, strerror(errno));
/* Try to ensure that the parent directory is there */
snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
char filename[1024];
struct passwd *pw;
- pw = getpwuid(getuid());
+ pw = getpwuid(original_uid);
if (pw == NULL)
fatal("Couldn't get password entry for current user (%i): %s",
- getuid(), strerror(errno));
+ original_uid, strerror(errno));
snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
SSH_PRNG_SEED_FILE);
/* trim to size */
entropy_sources = xrealloc(entcmd, (cur_cmd+1) * sizeof(entropy_source_t));
- debug("loaded %d entropy commands from %.100s", cur_cmd, cmdfilename);
+ debug("Loaded %d entropy commands from %.100s", cur_cmd, cmdfilename);
return (cur_cmd >= MIN_ENTROPY_SOURCES);
}
seed_rng(void)
{
void *old_sigchld_handler;
-
- if (!prng_commands_loaded) {
- if (!prng_read_commands(SSH_PRNG_COMMAND_FILE))
- fatal("PRNG initialisation failed -- exiting.");
- prng_commands_loaded = 1;
- }
+ if (!prng_initialised)
+ fatal("RNG not initialised");
+
/* Make sure some other sigchld handler doesn't reap our entropy */
/* commands */
old_sigchld_handler = signal(SIGCHLD, SIG_DFL);
- debug("Seeding random number generator.");
- debug("OpenSSL random status is now %i\n", RAND_status());
- debug("%i bytes from system calls", (int)stir_from_system());
- debug("%i bytes from programs", (int)stir_from_programs());
- debug("OpenSSL random status is now %i\n", RAND_status());
+ debug("Seeded RNG with %i bytes from programs", (int)stir_from_programs());
+ debug("Seeded RNG with %i bytes from system calls", (int)stir_from_system());
+
+ if (!RAND_status())
+ fatal("Not enough entropy in RNG");
signal(SIGCHLD, old_sigchld_handler);
if (!RAND_status())
fatal("Couldn't initialise builtin random number generator -- exiting.");
+}
- if (!prng_seed_loaded)
- {
- prng_seed_loaded = 1;
- prng_seed_saved = 0;
- prng_read_seedfile();
- fatal_add_cleanup(prng_seed_cleanup, NULL);
- atexit(prng_write_seedfile);
- }
+void init_rng(void)
+{
+ original_uid = getuid();
+
+ /* Read in collection commands */
+ if (!prng_read_commands(SSH_PRNG_COMMAND_FILE))
+ fatal("PRNG initialisation failed -- exiting.");
+
+ /* Set ourselves up to save a seed upon exit */
+ prng_seed_saved = 0;
+ prng_read_seedfile();
+ fatal_add_cleanup(prng_seed_cleanup, NULL);
+ atexit(prng_write_seedfile);
+
+ prng_initialised = 1;
}
+
#endif /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */