- (djm) [Makefile.in WARNING.RNG aclocal.m4 buildpkg.sh.in configure.ac]
[entropy.c ssh-add.c ssh-agent.c ssh-keygen.c ssh-keyscan.c]
[ssh-keysign.c ssh-pkcs11-helper.c ssh-rand-helper.8 ssh-rand-helper.c]
[ssh.c ssh_prng_cmds.in sshd.c contrib/aix/buildbff.sh]
[regress/README.regress] Remove ssh-rand-helper and all its
tentacles. PRNGd seeding has been rolled into entropy.c directly.
Thanks to tim@ for testing on affected platforms.
diff --git a/entropy.c b/entropy.c
index a821662..2d6d3ec 100644
--- a/entropy.c
+++ b/entropy.c
@@ -25,19 +25,19 @@
#include "includes.h"
#include <sys/types.h>
-#include <sys/wait.h>
-
-#ifdef HAVE_SYS_STAT_H
-# include <sys/stat.h>
+#include <sys/socket.h>
+#ifdef HAVE_SYS_UN_H
+# include <sys/un.h>
#endif
-#ifdef HAVE_FCNTL_H
-# include <fcntl.h>
-#endif
-#include <stdarg.h>
-#include <string.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <errno.h>
#include <signal.h>
+#include <string.h>
#include <unistd.h>
+#include <stddef.h> /* for offsetof */
#include <openssl/rand.h>
#include <openssl/crypto.h>
@@ -54,118 +54,128 @@
/*
* Portable OpenSSH PRNG seeding:
* If OpenSSL has not "internally seeded" itself (e.g. pulled data from
- * /dev/random), then we execute a "ssh-rand-helper" program which
- * collects entropy and writes it to stdout. The child program must
- * write at least RANDOM_SEED_SIZE bytes. The child is run with stderr
- * attached, so error/debugging output should be visible.
- *
- * XXX: we should tell the child how many bytes we need.
+ * /dev/random), then collect RANDOM_SEED_SIZE bytes of randomness from
+ * PRNGd.
*/
-
#ifndef OPENSSL_PRNG_ONLY
+
#define RANDOM_SEED_SIZE 48
-static uid_t original_uid, original_euid;
-#endif
-void
-seed_rng(void)
+/*
+ * Collect 'len' bytes of entropy into 'buf' from PRNGD/EGD daemon
+ * listening either on 'tcp_port', or via Unix domain socket at *
+ * 'socket_path'.
+ * Either a non-zero tcp_port or a non-null socket_path must be
+ * supplied.
+ * Returns 0 on success, -1 on error
+ */
+int
+get_random_bytes_prngd(unsigned char *buf, int len,
+ unsigned short tcp_port, char *socket_path)
{
-#ifndef OPENSSL_PRNG_ONLY
- int devnull;
- int p[2];
- pid_t pid;
- int ret;
- unsigned char buf[RANDOM_SEED_SIZE];
- mysig_t old_sigchld;
+ int fd, addr_len, rval, errors;
+ u_char msg[2];
+ struct sockaddr_storage addr;
+ struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr;
+ struct sockaddr_un *addr_un = (struct sockaddr_un *)&addr;
+ mysig_t old_sigpipe;
- if (RAND_status() == 1) {
- debug3("RNG is ready, skipping seeding");
- return;
+ /* Sanity checks */
+ if (socket_path == NULL && tcp_port == 0)
+ fatal("You must specify a port or a socket");
+ if (socket_path != NULL &&
+ strlen(socket_path) >= sizeof(addr_un->sun_path))
+ fatal("Random pool path is too long");
+ if (len <= 0 || len > 255)
+ fatal("Too many bytes (%d) to read from PRNGD", len);
+
+ memset(&addr, '\0', sizeof(addr));
+
+ if (tcp_port != 0) {
+ addr_in->sin_family = AF_INET;
+ addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+ addr_in->sin_port = htons(tcp_port);
+ addr_len = sizeof(*addr_in);
+ } else {
+ addr_un->sun_family = AF_UNIX;
+ strlcpy(addr_un->sun_path, socket_path,
+ sizeof(addr_un->sun_path));
+ addr_len = offsetof(struct sockaddr_un, sun_path) +
+ strlen(socket_path) + 1;
}
- debug3("Seeding PRNG from %s", SSH_RAND_HELPER);
+ old_sigpipe = mysignal(SIGPIPE, SIG_IGN);
- if ((devnull = open("/dev/null", O_RDWR)) == -1)
- fatal("Couldn't open /dev/null: %s", strerror(errno));
- if (pipe(p) == -1)
- fatal("pipe: %s", strerror(errno));
+ errors = 0;
+ rval = -1;
+reopen:
+ fd = socket(addr.ss_family, SOCK_STREAM, 0);
+ if (fd == -1) {
+ error("Couldn't create socket: %s", strerror(errno));
+ goto done;
+ }
- old_sigchld = signal(SIGCHLD, SIG_DFL);
- if ((pid = fork()) == -1)
- fatal("Couldn't fork: %s", strerror(errno));
- if (pid == 0) {
- dup2(devnull, STDIN_FILENO);
- dup2(p[1], STDOUT_FILENO);
- /* Keep stderr open for errors */
- close(p[0]);
- close(p[1]);
- close(devnull);
-
- if (original_uid != original_euid &&
- ( seteuid(getuid()) == -1 ||
- setuid(original_uid) == -1) ) {
- fprintf(stderr, "(rand child) setuid(%li): %s\n",
- (long int)original_uid, strerror(errno));
- _exit(1);
+ if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) {
+ if (tcp_port != 0) {
+ error("Couldn't connect to PRNGD port %d: %s",
+ tcp_port, strerror(errno));
+ } else {
+ error("Couldn't connect to PRNGD socket \"%s\": %s",
+ addr_un->sun_path, strerror(errno));
}
-
- execl(SSH_RAND_HELPER, "ssh-rand-helper", NULL);
- fprintf(stderr, "(rand child) Couldn't exec '%s': %s\n",
- SSH_RAND_HELPER, strerror(errno));
- _exit(1);
+ goto done;
}
- close(devnull);
- close(p[1]);
+ /* Send blocking read request to PRNGD */
+ msg[0] = 0x02;
+ msg[1] = len;
- memset(buf, '\0', sizeof(buf));
- ret = atomicio(read, p[0], buf, sizeof(buf));
- if (ret == -1)
- fatal("Couldn't read from ssh-rand-helper: %s",
+ if (atomicio(vwrite, fd, msg, sizeof(msg)) != sizeof(msg)) {
+ if (errno == EPIPE && errors < 10) {
+ close(fd);
+ errors++;
+ goto reopen;
+ }
+ error("Couldn't write to PRNGD socket: %s",
strerror(errno));
- if (ret != sizeof(buf))
- fatal("ssh-rand-helper child produced insufficient data");
+ goto done;
+ }
- close(p[0]);
-
- if (waitpid(pid, &ret, 0) == -1)
- fatal("Couldn't wait for ssh-rand-helper completion: %s",
+ if (atomicio(read, fd, buf, len) != (size_t)len) {
+ if (errno == EPIPE && errors < 10) {
+ close(fd);
+ errors++;
+ goto reopen;
+ }
+ error("Couldn't read from PRNGD socket: %s",
strerror(errno));
- signal(SIGCHLD, old_sigchld);
+ goto done;
+ }
- /* We don't mind if the child exits upon a SIGPIPE */
- if (!WIFEXITED(ret) &&
- (!WIFSIGNALED(ret) || WTERMSIG(ret) != SIGPIPE))
- fatal("ssh-rand-helper terminated abnormally");
- if (WEXITSTATUS(ret) != 0)
- fatal("ssh-rand-helper exit with exit status %d", ret);
-
- RAND_add(buf, sizeof(buf), sizeof(buf));
- memset(buf, '\0', sizeof(buf));
-
-#endif /* OPENSSL_PRNG_ONLY */
- if (RAND_status() != 1)
- fatal("PRNG is not seeded");
+ rval = 0;
+done:
+ mysignal(SIGPIPE, old_sigpipe);
+ if (fd != -1)
+ close(fd);
+ return rval;
}
-void
-init_rng(void)
+static int
+seed_from_prngd(unsigned char *buf, size_t bytes)
{
- /*
- * OpenSSL version numbers: MNNFFPPS: major minor fix patch status
- * We match major, minor, fix and status (not patch)
- */
- if ((SSLeay() ^ OPENSSL_VERSION_NUMBER) & ~0xff0L)
- fatal("OpenSSL version mismatch. Built against %lx, you "
- "have %lx", (u_long)OPENSSL_VERSION_NUMBER, SSLeay());
-
-#ifndef OPENSSL_PRNG_ONLY
- original_uid = getuid();
- original_euid = geteuid();
+#ifdef PRNGD_PORT
+ debug("trying egd/prngd port %d", PRNGD_PORT);
+ if (get_random_bytes_prngd(buf, bytes, PRNGD_PORT, NULL) == 0)
+ return 0;
#endif
+#ifdef PRNGD_SOCKET
+ debug("trying egd/prngd socket %s", PRNGD_SOCKET);
+ if (get_random_bytes_prngd(buf, bytes, 0, PRNGD_SOCKET) == 0)
+ return 0;
+#endif
+ return -1;
}
-#ifndef OPENSSL_PRNG_ONLY
void
rexec_send_rng_seed(Buffer *m)
{
@@ -191,4 +201,34 @@
RAND_add(buf, len, len);
}
}
+#endif /* OPENSSL_PRNG_ONLY */
+
+void
+seed_rng(void)
+{
+#ifndef OPENSSL_PRNG_ONLY
+ unsigned char buf[RANDOM_SEED_SIZE];
#endif
+ /*
+ * OpenSSL version numbers: MNNFFPPS: major minor fix patch status
+ * We match major, minor, fix and status (not patch)
+ */
+ if ((SSLeay() ^ OPENSSL_VERSION_NUMBER) & ~0xff0L)
+ fatal("OpenSSL version mismatch. Built against %lx, you "
+ "have %lx", (u_long)OPENSSL_VERSION_NUMBER, SSLeay());
+
+#ifndef OPENSSL_PRNG_ONLY
+ if (RAND_status() == 1) {
+ debug3("RNG is ready, skipping seeding");
+ return;
+ }
+
+ if (seed_from_prngd(buf, sizeof(buf)) == -1)
+ fatal("Could not obtain seed from PRNGd");
+ RAND_add(buf, sizeof(buf), sizeof(buf));
+ memset(buf, '\0', sizeof(buf));
+
+#endif /* OPENSSL_PRNG_ONLY */
+ if (RAND_status() != 1)
+ fatal("PRNG is not seeded");
+}