| /* |
| * 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 <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" |
| |
| RCSID("$Id: ssh-rand-helper.c,v 1.22 2005/02/16 02:20:07 dtucker Exp $"); |
| |
| /* 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; |
| 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 > 255) |
| fatal("Too many bytes to read from PRNGD"); |
| |
| 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) != 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); |
| mkdir(filename, 0700); |
| |
| 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 = xmalloc(num_cmds * sizeof(entropy_cmd_t)); |
| memset(entcmd, '\0', 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); |
| |
| 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; |
| 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(); |
| } |
| } |
| |
| log_init(argv[0], ll, SYSLOG_FACILITY_USER, 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 -> 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"); |
| } |