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-rw-r--r--crypto/openssh/ssh-rand-helper.c932
1 files changed, 932 insertions, 0 deletions
diff --git a/crypto/openssh/ssh-rand-helper.c b/crypto/openssh/ssh-rand-helper.c
new file mode 100644
index 0000000..fa50704
--- /dev/null
+++ b/crypto/openssh/ssh-rand-helper.c
@@ -0,0 +1,932 @@
+/*
+ * Copyright (c) 2001-2002 Damien Miller. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <string.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#ifdef HAVE_SYS_UN_H
+# include <sys/un.h>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <signal.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <openssl/rand.h>
+#include <openssl/sha.h>
+#include <openssl/crypto.h>
+
+/* SunOS 4.4.4 needs this */
+#ifdef HAVE_FLOATINGPOINT_H
+# include <floatingpoint.h>
+#endif /* HAVE_FLOATINGPOINT_H */
+
+#include "misc.h"
+#include "xmalloc.h"
+#include "atomicio.h"
+#include "pathnames.h"
+#include "log.h"
+
+/* Number of bytes we write out */
+#define OUTPUT_SEED_SIZE 48
+
+/* Length of on-disk seedfiles */
+#define SEED_FILE_SIZE 1024
+
+/* Maximum number of command-line arguments to read from file */
+#define NUM_ARGS 10
+
+/* Minimum number of usable commands to be considered sufficient */
+#define MIN_ENTROPY_SOURCES 16
+
+/* Path to on-disk seed file (relative to user's home directory */
+#ifndef SSH_PRNG_SEED_FILE
+# define SSH_PRNG_SEED_FILE _PATH_SSH_USER_DIR"/prng_seed"
+#endif
+
+/* Path to PRNG commands list */
+#ifndef SSH_PRNG_COMMAND_FILE
+# define SSH_PRNG_COMMAND_FILE SSHDIR "/ssh_prng_cmds"
+#endif
+
+extern char *__progname;
+
+#define WHITESPACE " \t\n"
+
+#ifndef RUSAGE_SELF
+# define RUSAGE_SELF 0
+#endif
+#ifndef RUSAGE_CHILDREN
+# define RUSAGE_CHILDREN 0
+#endif
+
+#if !defined(PRNGD_SOCKET) && !defined(PRNGD_PORT)
+# define USE_SEED_FILES
+#endif
+
+typedef struct {
+ /* Proportion of data that is entropy */
+ double rate;
+ /* Counter goes positive if this command times out */
+ unsigned int badness;
+ /* Increases by factor of two each timeout */
+ unsigned int sticky_badness;
+ /* Path to executable */
+ char *path;
+ /* argv to pass to executable */
+ char *args[NUM_ARGS]; /* XXX: arbitrary limit */
+ /* full command string (debug) */
+ char *cmdstring;
+} entropy_cmd_t;
+
+/* slow command timeouts (all in milliseconds) */
+/* static int entropy_timeout_default = ENTROPY_TIMEOUT_MSEC; */
+static int entropy_timeout_current = ENTROPY_TIMEOUT_MSEC;
+
+/* this is initialised from a file, by prng_read_commands() */
+static entropy_cmd_t *entropy_cmds = NULL;
+
+/* Prototypes */
+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_command_output(entropy_cmd_t *src, unsigned char *hash);
+int get_random_bytes_prngd(unsigned char *buf, int len,
+ unsigned short tcp_port, char *socket_path);
+
+/*
+ * 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)
+{
+ 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;
+
+ /* 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;
+ }
+
+ old_sigpipe = mysignal(SIGPIPE, SIG_IGN);
+
+ 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;
+ }
+
+ 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));
+ }
+ goto done;
+ }
+
+ /* Send blocking read request to PRNGD */
+ msg[0] = 0x02;
+ msg[1] = len;
+
+ 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));
+ goto done;
+ }
+
+ 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));
+ goto done;
+ }
+
+ rval = 0;
+done:
+ mysignal(SIGPIPE, old_sigpipe);
+ if (fd != -1)
+ close(fd);
+ return rval;
+}
+
+static int
+seed_from_prngd(unsigned char *buf, size_t bytes)
+{
+#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;
+}
+
+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)
+{
+#ifdef HAVE_GETRUSAGE
+ struct rusage ru;
+
+ if (getrusage(who, &ru) == -1)
+ return 0;
+
+ RAND_add(&ru, sizeof(ru), entropy_estimate);
+
+ return entropy_estimate;
+#else /* _HAVE_GETRUSAGE */
+ return 0;
+#endif /* _HAVE_GETRUSAGE */
+}
+
+static int
+timeval_diff(struct timeval *t1, struct timeval *t2)
+{
+ int secdiff, usecdiff;
+
+ secdiff = t2->tv_sec - t1->tv_sec;
+ usecdiff = (secdiff*1000000) + (t2->tv_usec - t1->tv_usec);
+ return (int)(usecdiff / 1000);
+}
+
+double
+hash_command_output(entropy_cmd_t *src, unsigned char *hash)
+{
+ char buf[8192];
+ fd_set rdset;
+ int bytes_read, cmd_eof, error_abort, msec_elapsed, p[2];
+ int status, total_bytes_read;
+ static int devnull = -1;
+ pid_t pid;
+ SHA_CTX sha;
+ struct timeval tv_start, tv_current;
+
+ debug3("Reading output from \'%s\'", src->cmdstring);
+
+ 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));
+
+ (void)gettimeofday(&tv_start, NULL); /* record start time */
+
+ switch (pid = fork()) {
+ case -1: /* Error */
+ close(p[0]);
+ close(p[1]);
+ fatal("Couldn't fork: %s", strerror(errno));
+ /* NOTREACHED */
+ case 0: /* Child */
+ dup2(devnull, STDIN_FILENO);
+ dup2(p[1], STDOUT_FILENO);
+ dup2(p[1], STDERR_FILENO);
+ close(p[0]);
+ close(p[1]);
+ close(devnull);
+
+ execv(src->path, (char**)(src->args));
+
+ debug("(child) Couldn't exec '%s': %s",
+ src->cmdstring, strerror(errno));
+ _exit(-1);
+ default: /* Parent */
+ break;
+ }
+
+ RAND_add(&pid, sizeof(&pid), 0.0);
+
+ close(p[1]);
+
+ /* Hash output from child */
+ SHA1_Init(&sha);
+
+ cmd_eof = error_abort = msec_elapsed = total_bytes_read = 0;
+ while (!error_abort && !cmd_eof) {
+ int ret;
+ struct timeval tv;
+ int msec_remaining;
+
+ (void) gettimeofday(&tv_current, 0);
+ msec_elapsed = timeval_diff(&tv_start, &tv_current);
+ if (msec_elapsed >= entropy_timeout_current) {
+ error_abort=1;
+ continue;
+ }
+ msec_remaining = entropy_timeout_current - msec_elapsed;
+
+ FD_ZERO(&rdset);
+ FD_SET(p[0], &rdset);
+ tv.tv_sec = msec_remaining / 1000;
+ tv.tv_usec = (msec_remaining % 1000) * 1000;
+
+ 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;
+ kill(pid, SIGINT);
+ break;
+ case 1:
+ /* command input */
+ do {
+ bytes_read = read(p[0], buf, sizeof(buf));
+ } while (bytes_read == -1 && errno == EINTR);
+ RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
+ if (bytes_read == -1) {
+ error_abort = 1;
+ break;
+ } else if (bytes_read) {
+ SHA1_Update(&sha, buf, bytes_read);
+ total_bytes_read += bytes_read;
+ } else {
+ cmd_eof = 1;
+ }
+ break;
+ case -1:
+ default:
+ /* error */
+ debug("Command '%s': select() failed: %s",
+ src->cmdstring, strerror(errno));
+ error_abort = 1;
+ break;
+ }
+ }
+
+ SHA1_Final(hash, &sha);
+
+ close(p[0]);
+
+ debug3("Time elapsed: %d msec", msec_elapsed);
+
+ if (waitpid(pid, &status, 0) == -1) {
+ error("Couldn't wait for child '%s' completion: %s",
+ src->cmdstring, strerror(errno));
+ return 0.0;
+ }
+
+ RAND_add(&status, sizeof(&status), 0.0);
+
+ if (error_abort) {
+ /*
+ * Closing p[0] on timeout causes the entropy command to
+ * SIGPIPE. Take whatever output we got, and mark this
+ * command as slow
+ */
+ debug2("Command '%s' timed out", src->cmdstring);
+ src->sticky_badness *= 2;
+ src->badness = src->sticky_badness;
+ return total_bytes_read;
+ }
+
+ if (WIFEXITED(status)) {
+ if (WEXITSTATUS(status) == 0) {
+ return total_bytes_read;
+ } else {
+ debug2("Command '%s' exit status was %d",
+ src->cmdstring, WEXITSTATUS(status));
+ src->badness = src->sticky_badness = 128;
+ return 0.0;
+ }
+ } else if (WIFSIGNALED(status)) {
+ debug2("Command '%s' returned on uncaught signal %d !",
+ src->cmdstring, status);
+ src->badness = src->sticky_badness = 128;
+ return 0.0;
+ } else
+ return 0.0;
+}
+
+double
+stir_from_system(void)
+{
+ double total_entropy_estimate;
+ long int i;
+
+ total_entropy_estimate = 0;
+
+ i = getpid();
+ RAND_add(&i, sizeof(i), 0.5);
+ total_entropy_estimate += 0.1;
+
+ i = getppid();
+ RAND_add(&i, sizeof(i), 0.5);
+ total_entropy_estimate += 0.1;
+
+ i = getuid();
+ RAND_add(&i, sizeof(i), 0.0);
+ i = getgid();
+ RAND_add(&i, sizeof(i), 0.0);
+
+ total_entropy_estimate += stir_gettimeofday(1.0);
+ total_entropy_estimate += stir_clock(0.5);
+ total_entropy_estimate += stir_rusage(RUSAGE_SELF, 2.0);
+
+ return total_entropy_estimate;
+}
+
+double
+stir_from_programs(void)
+{
+ int c;
+ double entropy, total_entropy;
+ unsigned char hash[SHA_DIGEST_LENGTH];
+
+ total_entropy = 0;
+ for(c = 0; entropy_cmds[c].path != NULL; c++) {
+ if (!entropy_cmds[c].badness) {
+ /* Hash output from command */
+ entropy = hash_command_output(&entropy_cmds[c],
+ hash);
+
+ /* Scale back estimate by command's rate */
+ entropy *= entropy_cmds[c].rate;
+
+ /* Upper bound of entropy is SHA_DIGEST_LENGTH */
+ if (entropy > SHA_DIGEST_LENGTH)
+ entropy = SHA_DIGEST_LENGTH;
+
+ /* Stir it in */
+ RAND_add(hash, sizeof(hash), entropy);
+
+ debug3("Got %0.2f bytes of entropy from '%s'",
+ entropy, entropy_cmds[c].cmdstring);
+
+ total_entropy += entropy;
+
+ /* Execution time should be a bit unpredictable */
+ total_entropy += stir_gettimeofday(0.05);
+ total_entropy += stir_clock(0.05);
+ total_entropy += stir_rusage(RUSAGE_SELF, 0.1);
+ total_entropy += stir_rusage(RUSAGE_CHILDREN, 0.1);
+ } else {
+ debug2("Command '%s' disabled (badness %d)",
+ entropy_cmds[c].cmdstring,
+ entropy_cmds[c].badness);
+
+ if (entropy_cmds[c].badness > 0)
+ entropy_cmds[c].badness--;
+ }
+ }
+
+ return total_entropy;
+}
+
+/*
+ * prng seedfile functions
+ */
+int
+prng_check_seedfile(char *filename)
+{
+ struct stat st;
+
+ /*
+ * XXX raceable: eg replace seed between this stat and subsequent
+ * open. Not such a problem because we don't really trust the
+ * seed file anyway.
+ * XXX: use secure path checking as elsewhere in OpenSSH
+ */
+ if (lstat(filename, &st) == -1) {
+ /* Give up on hard errors */
+ if (errno != ENOENT)
+ debug("WARNING: Couldn't stat random seed file "
+ "\"%.100s\": %s", filename, strerror(errno));
+ return 0;
+ }
+
+ /* regular file? */
+ if (!S_ISREG(st.st_mode))
+ 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())) {
+ debug("WARNING: PRNG seedfile %.100s must be mode 0600, "
+ "owned by uid %li", filename, (long int)getuid());
+ return 0;
+ }
+
+ return 1;
+}
+
+void
+prng_write_seedfile(void)
+{
+ int fd, save_errno;
+ unsigned char seed[SEED_FILE_SIZE];
+ char filename[MAXPATHLEN], tmpseed[MAXPATHLEN];
+ struct passwd *pw;
+ mode_t old_umask;
+
+ pw = getpwuid(getuid());
+ if (pw == NULL)
+ fatal("Couldn't get password entry for current user "
+ "(%li): %s", (long int)getuid(), strerror(errno));
+
+ /* Try to ensure that the parent directory is there */
+ snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
+ _PATH_SSH_USER_DIR);
+ if (mkdir(filename, 0700) < 0 && errno != EEXIST)
+ fatal("mkdir %.200s: %s", filename, strerror(errno));
+
+ snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
+ SSH_PRNG_SEED_FILE);
+
+ strlcpy(tmpseed, filename, sizeof(tmpseed));
+ if (strlcat(tmpseed, ".XXXXXXXXXX", sizeof(tmpseed)) >=
+ sizeof(tmpseed))
+ fatal("PRNG seed filename too long");
+
+ if (RAND_bytes(seed, sizeof(seed)) <= 0)
+ fatal("PRNG seed extraction failed");
+
+ /* Don't care if the seed doesn't exist */
+ prng_check_seedfile(filename);
+
+ old_umask = umask(0177);
+
+ if ((fd = mkstemp(tmpseed)) == -1) {
+ debug("WARNING: couldn't make temporary PRNG seedfile %.100s "
+ "(%.100s)", tmpseed, strerror(errno));
+ } else {
+ debug("writing PRNG seed to file %.100s", tmpseed);
+ if (atomicio(vwrite, fd, &seed, sizeof(seed)) < sizeof(seed)) {
+ save_errno = errno;
+ close(fd);
+ unlink(tmpseed);
+ fatal("problem writing PRNG seedfile %.100s "
+ "(%.100s)", filename, strerror(save_errno));
+ }
+ close(fd);
+ debug("moving temporary PRNG seed to file %.100s", filename);
+ if (rename(tmpseed, filename) == -1) {
+ save_errno = errno;
+ unlink(tmpseed);
+ fatal("problem renaming PRNG seedfile from %.100s "
+ "to %.100s (%.100s)", tmpseed, filename,
+ strerror(save_errno));
+ }
+ }
+ umask(old_umask);
+}
+
+void
+prng_read_seedfile(void)
+{
+ int fd;
+ char seed[SEED_FILE_SIZE], filename[MAXPATHLEN];
+ struct passwd *pw;
+
+ pw = getpwuid(getuid());
+ if (pw == NULL)
+ fatal("Couldn't get password entry for current user "
+ "(%li): %s", (long int)getuid(), strerror(errno));
+
+ snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
+ SSH_PRNG_SEED_FILE);
+
+ debug("loading PRNG seed from file %.100s", filename);
+
+ if (!prng_check_seedfile(filename)) {
+ verbose("Random seed file not found or invalid, ignoring.");
+ return;
+ }
+
+ /* open the file and read in the seed */
+ fd = open(filename, O_RDONLY);
+ if (fd == -1)
+ fatal("could not open PRNG seedfile %.100s (%.100s)",
+ filename, strerror(errno));
+
+ if (atomicio(read, fd, &seed, sizeof(seed)) < sizeof(seed)) {
+ verbose("invalid or short read from PRNG seedfile "
+ "%.100s - ignoring", filename);
+ memset(seed, '\0', sizeof(seed));
+ }
+ close(fd);
+
+ /* stir in the seed, with estimated entropy zero */
+ RAND_add(&seed, sizeof(seed), 0.0);
+}
+
+
+/*
+ * entropy command initialisation functions
+ */
+int
+prng_read_commands(char *cmdfilename)
+{
+ char cmd[SEED_FILE_SIZE], *cp, line[1024], path[SEED_FILE_SIZE];
+ double est;
+ entropy_cmd_t *entcmd;
+ FILE *f;
+ int cur_cmd, linenum, num_cmds, arg;
+
+ if ((f = fopen(cmdfilename, "r")) == NULL) {
+ fatal("couldn't read entropy commands file %.100s: %.100s",
+ cmdfilename, strerror(errno));
+ }
+
+ num_cmds = 64;
+ entcmd = xcalloc(num_cmds, sizeof(entropy_cmd_t));
+
+ /* Read in file */
+ cur_cmd = linenum = 0;
+ while (fgets(line, sizeof(line), f)) {
+ linenum++;
+
+ /* Skip leading whitespace, blank lines and comments */
+ cp = line + strspn(line, WHITESPACE);
+ if ((*cp == 0) || (*cp == '#'))
+ continue; /* done with this line */
+
+ /*
+ * The first non-whitespace char should be a double quote
+ * delimiting the commandline
+ */
+ if (*cp != '"') {
+ error("bad entropy command, %.100s line %d",
+ cmdfilename, linenum);
+ continue;
+ }
+
+ /*
+ * First token, command args (incl. argv[0]) in double
+ * quotes
+ */
+ cp = strtok(cp, "\"");
+ if (cp == NULL) {
+ error("missing or bad command string, %.100s "
+ "line %d -- ignored", cmdfilename, linenum);
+ continue;
+ }
+ strlcpy(cmd, cp, sizeof(cmd));
+
+ /* Second token, full command path */
+ if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
+ error("missing command path, %.100s "
+ "line %d -- ignored", cmdfilename, linenum);
+ continue;
+ }
+
+ /* Did configure mark this as dead? */
+ if (strncmp("undef", cp, 5) == 0)
+ continue;
+
+ strlcpy(path, cp, sizeof(path));
+
+ /* Third token, entropy rate estimate for this command */
+ if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
+ error("missing entropy estimate, %.100s "
+ "line %d -- ignored", cmdfilename, linenum);
+ continue;
+ }
+ est = strtod(cp, NULL);
+
+ /* end of line */
+ if ((cp = strtok(NULL, WHITESPACE)) != NULL) {
+ error("garbage at end of line %d in %.100s "
+ "-- ignored", linenum, cmdfilename);
+ continue;
+ }
+
+ /* save the command for debug messages */
+ entcmd[cur_cmd].cmdstring = xstrdup(cmd);
+
+ /* split the command args */
+ cp = strtok(cmd, WHITESPACE);
+ arg = 0;
+ do {
+ entcmd[cur_cmd].args[arg] = xstrdup(cp);
+ arg++;
+ } while(arg < NUM_ARGS && (cp = strtok(NULL, WHITESPACE)));
+
+ if (strtok(NULL, WHITESPACE))
+ error("ignored extra commands (max %d), %.100s "
+ "line %d", NUM_ARGS, cmdfilename, linenum);
+
+ /* Copy the command path and rate estimate */
+ entcmd[cur_cmd].path = xstrdup(path);
+ entcmd[cur_cmd].rate = est;
+
+ /* Initialise other values */
+ entcmd[cur_cmd].sticky_badness = 1;
+
+ cur_cmd++;
+
+ /*
+ * If we've filled the array, reallocate it twice the size
+ * Do this now because even if this we're on the last
+ * command we need another slot to mark the last entry
+ */
+ if (cur_cmd == num_cmds) {
+ num_cmds *= 2;
+ entcmd = xrealloc(entcmd, num_cmds,
+ sizeof(entropy_cmd_t));
+ }
+ }
+
+ /* zero the last entry */
+ memset(&entcmd[cur_cmd], '\0', sizeof(entropy_cmd_t));
+
+ /* trim to size */
+ entropy_cmds = xrealloc(entcmd, (cur_cmd + 1),
+ sizeof(entropy_cmd_t));
+
+ debug("Loaded %d entropy commands from %.100s", cur_cmd,
+ cmdfilename);
+
+ fclose(f);
+ return cur_cmd < MIN_ENTROPY_SOURCES ? -1 : 0;
+}
+
+void
+usage(void)
+{
+ fprintf(stderr, "Usage: %s [options]\n", __progname);
+ fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
+ fprintf(stderr, " Multiple -v increases verbosity.\n");
+ fprintf(stderr, " -x Force output in hexadecimal (for debugging)\n");
+ fprintf(stderr, " -X Force output in binary\n");
+ fprintf(stderr, " -b bytes Number of bytes to output (default %d)\n",
+ OUTPUT_SEED_SIZE);
+}
+
+int
+main(int argc, char **argv)
+{
+ unsigned char *buf;
+ int ret, ch, debug_level, output_hex, bytes;
+ extern char *optarg;
+ extern int optind;
+ LogLevel ll;
+
+ __progname = ssh_get_progname(argv[0]);
+ log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
+
+ ll = SYSLOG_LEVEL_INFO;
+ debug_level = output_hex = 0;
+ bytes = OUTPUT_SEED_SIZE;
+
+ /* Don't write binary data to a tty, unless we are forced to */
+ if (isatty(STDOUT_FILENO))
+ output_hex = 1;
+
+ while ((ch = getopt(argc, argv, "vxXhb:")) != -1) {
+ switch (ch) {
+ case 'v':
+ if (debug_level < 3)
+ ll = SYSLOG_LEVEL_DEBUG1 + debug_level++;
+ break;
+ case 'x':
+ output_hex = 1;
+ break;
+ case 'X':
+ output_hex = 0;
+ break;
+ case 'b':
+ if ((bytes = atoi(optarg)) <= 0)
+ fatal("Invalid number of output bytes");
+ break;
+ case 'h':
+ usage();
+ exit(0);
+ default:
+ error("Invalid commandline option");
+ usage();
+ exit(1);
+ }
+ }
+ log_init(argv[0], ll, SYSLOG_FACILITY_USER, 1);
+
+ if (argc != optind) {
+ error("Unexpected commandline arguments.");
+ usage();
+ exit(1);
+ }
+
+#ifdef USE_SEED_FILES
+ prng_read_seedfile();
+#endif
+
+ buf = xmalloc(bytes);
+
+ /*
+ * Seed the RNG from wherever we can
+ */
+
+ /* Take whatever is on the stack, but don't credit it */
+ RAND_add(buf, bytes, 0);
+
+ debug("Seeded RNG with %i bytes from system calls",
+ (int)stir_from_system());
+
+ /* try prngd, fall back to commands if prngd fails or not configured */
+ if (seed_from_prngd(buf, bytes) == 0) {
+ RAND_add(buf, bytes, bytes);
+ } else {
+ /* Read in collection commands */
+ if (prng_read_commands(SSH_PRNG_COMMAND_FILE) == -1)
+ fatal("PRNG initialisation failed -- exiting.");
+ debug("Seeded RNG with %i bytes from programs",
+ (int)stir_from_programs());
+ }
+
+#ifdef USE_SEED_FILES
+ prng_write_seedfile();
+#endif
+
+ /*
+ * Write the seed to stdout
+ */
+
+ if (!RAND_status())
+ fatal("Not enough entropy in RNG");
+
+ if (RAND_bytes(buf, bytes) <= 0)
+ fatal("Couldn't extract entropy from PRNG");
+
+ if (output_hex) {
+ for(ret = 0; ret < bytes; ret++)
+ printf("%02x", (unsigned char)(buf[ret]));
+ printf("\n");
+ } else
+ ret = atomicio(vwrite, STDOUT_FILENO, buf, bytes);
+
+ memset(buf, '\0', bytes);
+ xfree(buf);
+
+ return ret == bytes ? 0 : 1;
+}
+
+/*
+ * We may attempt to re-seed during mkstemp if we are using the one in the
+ * compat library (via mkstemp -> _gettemp -> arc4random -> seed_rng) so we
+ * need our own seed_rng(). We must also check that we have enough entropy.
+ */
+void
+seed_rng(void)
+{
+ if (!RAND_status())
+ fatal("Not enough entropy in RNG");
+}
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