/*
- * Copyright (c) 2000 Damien Miller. All rights reserved.
+ * Copyright (c) 2001 Damien Miller. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by Markus Friedl.
- * 4. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
#include "includes.h"
-#include "ssh.h"
-#include "xmalloc.h"
+#include <sys/types.h>
+#include <sys/wait.h>
-#ifdef HAVE_OPENSSL
-# include <openssl/rand.h>
-# include <openssl/sha.h>
-#endif
-#ifdef HAVE_SSL
-# include <ssl/rand.h>
-# include <ssl/sha.h>
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
#endif
-RCSID("$Id$");
-
-#ifdef EGD_SOCKET
-#ifndef offsetof
-# define offsetof(type, member) ((size_t) &((type *)0)->member)
+#ifdef HAVE_FCNTL_H
+# include <fcntl.h>
#endif
-/* Collect entropy from EGD */
-void get_random_bytes(unsigned char *buf, int len)
-{
- static int egd_socket = -1;
- int c;
- char egd_message[2] = { 0x02, 0x00 };
- struct sockaddr_un addr;
- int addr_len;
+#include <stdarg.h>
+#include <string.h>
+#include <signal.h>
+#include <unistd.h>
- memset(&addr, '\0', sizeof(addr));
- addr.sun_family = AF_UNIX;
-
- /* FIXME: compile time check? */
- if (sizeof(EGD_SOCKET) > sizeof(addr.sun_path))
- fatal("Random pool path is too long");
-
- strcpy(addr.sun_path, EGD_SOCKET);
-
- 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));
- }
+#include <openssl/rand.h>
+#include <openssl/crypto.h>
+#include <openssl/err.h>
- if (len > 255)
- fatal("Too many bytes to read from EGD");
-
- /* Send blocking read request to EGD */
- egd_message[1] = len;
+#include "ssh.h"
+#include "misc.h"
+#include "xmalloc.h"
+#include "atomicio.h"
+#include "pathnames.h"
+#include "log.h"
+#include "buffer.h"
- 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));
+/*
+ * 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.
+ */
- c = atomicio(read, egd_socket, buf, len);
- if (c <= 0)
- fatal("Couldn't read from EGD socket \"%s\": %s", EGD_SOCKET, strerror(errno));
-
- close(EGD_SOCKET);
-}
-#else /* !EGD_SOCKET */
-#ifdef RANDOM_POOL
-/* Collect entropy from /dev/urandom or pipe */
-void get_random_bytes(unsigned char *buf, int len)
+#ifndef OPENSSL_PRNG_ONLY
+#define RANDOM_SEED_SIZE 48
+static uid_t original_uid, original_euid;
+#endif
+
+void
+seed_rng(void)
{
- static int random_pool = -1;
- int c;
+#ifndef OPENSSL_PRNG_ONLY
+ int devnull;
+ int p[2];
+ pid_t pid;
+ int ret;
+ unsigned char buf[RANDOM_SEED_SIZE];
+ mysig_t old_sigchld;
- 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));
+ if (RAND_status() == 1) {
+ debug3("RNG is ready, skipping seeding");
+ return;
}
-
- c = atomicio(read, random_pool, buf, len);
- if (c <= 0)
- fatal("Couldn't read from random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
-}
-#endif /* RANDOM_POOL */
-#endif /* EGD_SOCKET */
-#if !defined(EGD_SOCKET) && !defined(RANDOM_POOL)
-/*
- * FIXME: proper entropy estimations. All current values are guesses
- * FIXME: Need timeout for slow moving programs
- * FIXME: More entropy sources
- */
+ debug3("Seeding PRNG from %s", SSH_RAND_HELPER);
-double stir_from_system(void);
-double stir_from_programs(void);
-double stir_gettimeofday(double entropy_estimate);
-double stir_clock(double entropy_estimate);
-double stir_rusage(int who, double entropy_estimate);
-double hash_output_from_command(const char *path, const char **args, char *hash);
+ 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));
+
+ 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);
+ }
-typedef struct
-{
- /* Proportion of data that is entropy */
- double rate;
- /* Path to executable */
- const char *path;
- /* argv to pass to executable */
- const char *args[5];
-} entropy_source_t;
+ 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);
+ }
-entropy_source_t entropy_sources[] = {
-#ifdef PROG_LS
- { 0.002, PROG_LS, { "ls", "-alni", "/var/log", NULL } },
- { 0.002, PROG_LS, { "ls", "-alni", "/var/adm", NULL } },
- { 0.002, PROG_LS, { "ls", "-alni", "/var/mail", NULL } },
- { 0.002, PROG_LS, { "ls", "-alni", "/var/spool/mail", NULL } },
- { 0.002, PROG_LS, { "ls", "-alni", "/proc", NULL } },
- { 0.002, PROG_LS, { "ls", "-alni", "/tmp", NULL } },
-#endif
-#ifdef PROG_NETSTAT
- { 0.005, PROG_NETSTAT, { "netstat","-an", NULL, NULL } },
- { 0.010, PROG_NETSTAT, { "netstat","-in", NULL, NULL } },
- { 0.002, PROG_NETSTAT, { "netstat","-rn", NULL, NULL } },
- { 0.002, PROG_NETSTAT, { "netstat","-s", NULL, NULL } },
-#endif
-#ifdef PROG_ARP
- { 0.002, PROG_ARP, { "arp","-a","-n", NULL } },
-#endif
-#ifdef PROG_IFCONFIG
- { 0.002, PROG_IFCONFIG, { "ifconfig", "-a", NULL, NULL } },
-#endif
-#ifdef PROG_PS
- { 0.003, PROG_PS, { "ps", "laxww", NULL, NULL } },
- { 0.003, PROG_PS, { "ps", "-al", NULL, NULL } },
- { 0.003, PROG_PS, { "ps", "-efl", NULL, NULL } },
-#endif
-#ifdef PROG_W
- { 0.005, PROG_W, { "w", NULL, NULL, NULL } },
-#endif
-#ifdef PROG_WHO
- { 0.001, PROG_WHO, { "who","-i", NULL, NULL } },
-#endif
-#ifdef PROG_LAST
- { 0.001, PROG_LAST, { "last", NULL, NULL, NULL } },
-#endif
-#ifdef PROG_LASTLOG
- { 0.001, PROG_LASTLOG, { "lastlog", NULL, NULL, NULL } },
-#endif
-#ifdef PROG_DF
- { 0.010, PROG_DF, { "df", NULL, NULL, NULL } },
- { 0.010, PROG_DF, { "df", "-i", NULL, NULL } },
-#endif
-#ifdef PROG_VMSTAT
- { 0.010, PROG_VMSTAT, { "vmstat", NULL, NULL, NULL } },
-#endif
-#ifdef PROG_UPTIME
- { 0.001, PROG_UPTIME, { "uptime", NULL, NULL, NULL } },
-#endif
-#ifdef PROG_IPCS
- { 0.001, PROG_IPCS, { "-a", NULL, NULL, NULL } },
-#endif
-#ifdef PROG_TAIL
- { 0.001, PROG_TAIL, { "tail", "-200", "/var/log/messages", NULL, NULL } },
- { 0.001, PROG_TAIL, { "tail", "-200", "/var/log/syslog", NULL, NULL } },
- { 0.001, PROG_TAIL, { "tail", "-200", "/var/adm/messages", NULL, NULL } },
- { 0.001, PROG_TAIL, { "tail", "-200", "/var/adm/syslog", NULL, NULL } },
- { 0.001, PROG_TAIL, { "tail", "-200", "/var/log/maillog", NULL, NULL } },
- { 0.001, PROG_TAIL, { "tail", "-200", "/var/adm/maillog", NULL, NULL } },
-#endif
- { 0.000, NULL, { NULL, NULL, NULL, NULL, NULL } },
-};
+ close(devnull);
+ close(p[1]);
+ 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",
+ strerror(errno));
+ if (ret != sizeof(buf))
+ fatal("ssh-rand-helper child produced insufficient data");
-double
-stir_from_system(void)
-{
- double total_entropy_estimate;
- long int i;
-
- total_entropy_estimate = 0;
-
- i = getpid();
- RAND_add(&i, sizeof(i), 0.1);
- total_entropy_estimate += 0.1;
-
- i = getppid();
- RAND_add(&i, sizeof(i), 0.1);
- total_entropy_estimate += 0.1;
+ close(p[0]);
- i = getuid();
- RAND_add(&i, sizeof(i), 0.0);
- i = getgid();
- RAND_add(&i, sizeof(i), 0.0);
+ if (waitpid(pid, &ret, 0) == -1)
+ fatal("Couldn't wait for ssh-rand-helper completion: %s",
+ strerror(errno));
+ signal(SIGCHLD, old_sigchld);
- total_entropy_estimate += stir_gettimeofday(1.0);
- total_entropy_estimate += stir_clock(0.2);
- total_entropy_estimate += stir_rusage(RUSAGE_SELF, 2.0);
+ /* 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);
- return(total_entropy_estimate);
+ 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");
}
-double
-stir_from_programs(void)
+void
+init_rng(void)
{
- int i;
- int c;
- double entropy_estimate;
- double total_entropy_estimate;
- char hash[SHA_DIGEST_LENGTH];
-
/*
- * Run through list of programs twice to catch differences
+ * OpenSSL version numbers: MNNFFPPS: major minor fix patch status
+ * We match major, minor, fix and status (not patch)
*/
- total_entropy_estimate = 0;
- for(i = 0; i < 2; i++) {
- c = 0;
- while (entropy_sources[c].path != NULL) {
- /* Hash output from command */
- entropy_estimate = hash_output_from_command(entropy_sources[c].path,
- entropy_sources[c].args, hash);
-
- /* Scale back entropy estimate according to command's rate */
- entropy_estimate *= entropy_sources[c].rate;
-
- /* Upper bound of entropy estimate is SHA_DIGEST_LENGTH */
- if (entropy_estimate > SHA_DIGEST_LENGTH)
- entropy_estimate = SHA_DIGEST_LENGTH;
+ if ((SSLeay() ^ OPENSSL_VERSION_NUMBER) & ~0xff0L)
+ fatal("OpenSSL version mismatch. Built against %lx, you "
+ "have %lx", OPENSSL_VERSION_NUMBER, SSLeay());
- /* * Scale back estimates for subsequent passes through list */
- entropy_estimate /= 10.0 * (i + 1.0);
-
- /* Stir it in */
- RAND_add(hash, sizeof(hash), entropy_estimate);
-
-/* FIXME: turn this off later */
-#if 1
- debug("Got %0.2f bytes of entropy from %s", entropy_estimate,
- entropy_sources[c].path);
+#ifndef OPENSSL_PRNG_ONLY
+ original_uid = getuid();
+ original_euid = geteuid();
#endif
-
- total_entropy_estimate += entropy_estimate;
-
- /* Execution times should be a little unpredictable */
- total_entropy_estimate += stir_gettimeofday(0.05);
- total_entropy_estimate += stir_clock(0.05);
- total_entropy_estimate += stir_rusage(RUSAGE_SELF, 0.1);
- total_entropy_estimate += stir_rusage(RUSAGE_CHILDREN, 0.1);
-
- c++;
- }
- }
-
- return(total_entropy_estimate);
-}
-
-double
-stir_gettimeofday(double entropy_estimate)
-{
- struct timeval tv;
-
- if (gettimeofday(&tv, NULL) == -1)
- fatal("Couldn't gettimeofday: %s", strerror(errno));
-
- RAND_add(&tv, sizeof(tv), entropy_estimate);
-
- return(entropy_estimate);
-}
-
-double
-stir_clock(double entropy_estimate)
-{
-#ifdef HAVE_CLOCK
- clock_t c;
-
- c = clock();
- RAND_add(&c, sizeof(c), entropy_estimate);
-
- return(entropy_estimate);
-#else /* _HAVE_CLOCK */
- return(0);
-#endif /* _HAVE_CLOCK */
}
-double
-stir_rusage(int who, double entropy_estimate)
+#ifndef OPENSSL_PRNG_ONLY
+void
+rexec_send_rng_seed(Buffer *m)
{
-#ifdef HAVE_GETRUSAGE
- struct rusage ru;
-
- if (getrusage(who, &ru) == -1)
- fatal("Couldn't getrusage: %s", strerror(errno));
-
- RAND_add(&ru, sizeof(ru), 0.1);
-
- return(entropy_estimate);
-#else /* _HAVE_GETRUSAGE */
- return(0);
-#endif /* _HAVE_GETRUSAGE */
+ u_char buf[RANDOM_SEED_SIZE];
+
+ if (RAND_bytes(buf, sizeof(buf)) <= 0) {
+ error("Couldn't obtain random bytes (error %ld)",
+ ERR_get_error());
+ buffer_put_string(m, "", 0);
+ } else
+ buffer_put_string(m, buf, sizeof(buf));
}
-double
-hash_output_from_command(const char *path, const char **args, char *hash)
+void
+rexec_recv_rng_seed(Buffer *m)
{
- static int devnull = -1;
- int p[2];
- pid_t pid;
- int status;
- char buf[2048];
- int bytes_read;
- int total_bytes_read;
- SHA_CTX sha;
-
- if (devnull == -1) {
- devnull = open("/dev/null", O_RDWR);
- if (devnull == -1)
- fatal("Couldn't open /dev/null: %s", strerror(errno));
- }
-
- if (pipe(p) == -1)
- fatal("Couldn't open pipe: %s", strerror(errno));
-
- switch (pid = fork()) {
- case -1: /* Error */
- close(p[0]);
- close(p[1]);
- fatal("Couldn't fork: %s", strerror(errno));
- /* NOTREACHED */
- case 0: /* Child */
- close(0);
- close(1);
- close(2);
- dup2(devnull, 0);
- dup2(p[1], 1);
- dup2(p[1], 2);
- close(p[0]);
- close(p[1]);
- close(devnull);
+ u_char *buf;
+ u_int len;
- execv(path, (char**)args);
- debug("(child) Couldn't exec '%s': %s", path, strerror(errno));
- _exit(-1);
- default: /* Parent */
- break;
+ buf = buffer_get_string_ret(m, &len);
+ if (buf != NULL) {
+ debug3("rexec_recv_rng_seed: seeding rng with %u bytes", len);
+ RAND_add(buf, len, len);
}
-
- RAND_add(&pid, sizeof(&pid), 0.0);
-
- close(p[1]);
-
- /* Hash output from child */
- SHA1_Init(&sha);
- total_bytes_read = 0;
- while ((bytes_read = read(p[0], buf, sizeof(buf))) > 0) {
- SHA1_Update(&sha, buf, bytes_read);
- total_bytes_read += bytes_read;
- RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
- }
- SHA1_Final(hash, &sha);
-
- close(p[0]);
-
- if (waitpid(pid, &status, 0) == -1) {
- error("Couldn't wait for child '%s' completion: %s", path,
- strerror(errno));
- return(-1);
- }
-
- RAND_add(&status, sizeof(&status), 0.0);
-
- if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
- return(0.0);
- else
- return(total_bytes_read);
}
-#endif /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
-
-#if defined(EGD_SOCKET) || defined(RANDOM_POOL)
-/*
- * Seed OpenSSL's random number pool from Kernel random number generator
- * or EGD
- */
-void
-seed_rng(void)
-{
- char buf[32];
-
- debug("Seeding random number generator");
- get_random_bytes(buf, sizeof(buf));
- RAND_add(buf, sizeof(buf), sizeof(buf));
- memset(buf, '\0', sizeof(buf));
-}
-#else /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
-/*
- * Conditionally Seed OpenSSL's random number pool syscalls and program output
- */
-void
-seed_rng(void)
-{
- 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());
-}
-#endif /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
+#endif
andersk / openssh.git / blobdiff