diff options
Diffstat (limited to 'crypto/openssh/ssh-rand-helper.c')
-rw-r--r-- | crypto/openssh/ssh-rand-helper.c | 932 |
1 files changed, 0 insertions, 932 deletions
diff --git a/crypto/openssh/ssh-rand-helper.c b/crypto/openssh/ssh-rand-helper.c deleted file mode 100644 index fa50704..0000000 --- a/crypto/openssh/ssh-rand-helper.c +++ /dev/null @@ -1,932 +0,0 @@ -/* - * 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"); -} |