| /* |
| * Copyright (c) 2000 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> |
| |
| /* SunOS 4.4.4 needs this */ |
| #ifdef HAVE_FLOATINGPOINT_H |
| # include <floatingpoint.h> |
| #endif /* HAVE_FLOATINGPOINT_H */ |
| |
| #include "ssh.h" |
| #include "xmalloc.h" |
| #include "atomicio.h" |
| #include "log.h" |
| |
| RCSID("$Id: entropy.c,v 1.24 2001/01/22 05:34:41 mouring Exp $"); |
| |
| #ifndef offsetof |
| # define offsetof(type, member) ((size_t) &((type *)0)->member) |
| #endif |
| |
| /* Number of times to pass through command list gathering entropy */ |
| #define NUM_ENTROPY_RUNS 1 |
| |
| /* Scale entropy estimates back by this amount on subsequent runs */ |
| #define SCALE_PER_RUN 10.0 |
| |
| /* Minimum number of commands to be considered valid */ |
| #define MIN_ENTROPY_SOURCES 16 |
| |
| #define WHITESPACE " \t\n" |
| |
| #ifndef RUSAGE_SELF |
| # define RUSAGE_SELF 0 |
| #endif |
| #ifndef RUSAGE_CHILDREN |
| # define RUSAGE_CHILDREN 0 |
| #endif |
| |
| #if defined(EGD_SOCKET) || defined(RANDOM_POOL) |
| |
| #ifdef EGD_SOCKET |
| /* Collect entropy from EGD */ |
| int get_random_bytes(unsigned char *buf, int len) |
| { |
| int fd; |
| char msg[2]; |
| struct sockaddr_un addr; |
| int addr_len; |
| |
| /* Sanity checks */ |
| if (sizeof(EGD_SOCKET) > sizeof(addr.sun_path)) |
| fatal("Random pool path is too long"); |
| if (len > 255) |
| fatal("Too many bytes to read from EGD"); |
| |
| memset(&addr, '\0', sizeof(addr)); |
| addr.sun_family = AF_UNIX; |
| strlcpy(addr.sun_path, EGD_SOCKET, sizeof(addr.sun_path)); |
| addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(EGD_SOCKET); |
| |
| fd = socket(AF_UNIX, SOCK_STREAM, 0); |
| if (fd == -1) { |
| error("Couldn't create AF_UNIX socket: %s", strerror(errno)); |
| return(0); |
| } |
| |
| if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) { |
| error("Couldn't connect to EGD socket \"%s\": %s", |
| addr.sun_path, strerror(errno)); |
| close(fd); |
| return(0); |
| } |
| |
| /* Send blocking read request to EGD */ |
| msg[0] = 0x02; |
| msg[1] = len; |
| |
| if (atomicio(write, fd, msg, sizeof(msg)) != sizeof(msg)) { |
| error("Couldn't write to EGD socket \"%s\": %s", |
| EGD_SOCKET, strerror(errno)); |
| close(fd); |
| return(0); |
| } |
| |
| if (atomicio(read, fd, buf, len) != len) { |
| error("Couldn't read from EGD socket \"%s\": %s", |
| EGD_SOCKET, strerror(errno)); |
| close(fd); |
| return(0); |
| } |
| |
| close(fd); |
| |
| return(1); |
| } |
| #else /* !EGD_SOCKET */ |
| #ifdef RANDOM_POOL |
| /* Collect entropy from /dev/urandom or pipe */ |
| int get_random_bytes(unsigned char *buf, int len) |
| { |
| int random_pool; |
| |
| random_pool = open(RANDOM_POOL, O_RDONLY); |
| if (random_pool == -1) { |
| error("Couldn't open random pool \"%s\": %s", |
| RANDOM_POOL, strerror(errno)); |
| return(0); |
| } |
| |
| if (atomicio(read, random_pool, buf, len) != len) { |
| error("Couldn't read from random pool \"%s\": %s", |
| RANDOM_POOL, strerror(errno)); |
| close(random_pool); |
| return(0); |
| } |
| |
| close(random_pool); |
| |
| return(1); |
| } |
| #endif /* RANDOM_POOL */ |
| #endif /* EGD_SOCKET */ |
| |
| /* |
| * 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"); |
| |
| if (!get_random_bytes(buf, sizeof(buf))) { |
| if (!RAND_status()) |
| fatal("Entropy collection failed and entropy exhausted"); |
| } else { |
| RAND_add(buf, sizeof(buf), sizeof(buf)); |
| } |
| |
| memset(buf, '\0', sizeof(buf)); |
| } |
| |
| /* No-op */ |
| void init_rng(void) {} |
| |
| #else /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */ |
| |
| /* |
| * FIXME: proper entropy estimations. All current values are guesses |
| * FIXME: (ATL) do estimates at compile time? |
| * FIXME: More entropy sources |
| */ |
| |
| /* slow command timeouts (all in milliseconds) */ |
| /* static int entropy_timeout_default = ENTROPY_TIMEOUT_MSEC; */ |
| static int entropy_timeout_current = ENTROPY_TIMEOUT_MSEC; |
| |
| static int prng_seed_saved = 0; |
| static int prng_initialised = 0; |
| uid_t original_uid; |
| |
| 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[5]; |
| /* full command string (debug) */ |
| char *cmdstring; |
| } entropy_source_t; |
| |
| 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(entropy_source_t *src, char *hash); |
| |
| /* this is initialised from a file, by prng_read_commands() */ |
| entropy_source_t *entropy_sources = NULL; |
| |
| 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 i; |
| int c; |
| double entropy_estimate; |
| double total_entropy_estimate; |
| char hash[SHA_DIGEST_LENGTH]; |
| |
| total_entropy_estimate = 0; |
| for(i = 0; i < NUM_ENTROPY_RUNS; i++) { |
| c = 0; |
| while (entropy_sources[c].path != NULL) { |
| |
| if (!entropy_sources[c].badness) { |
| /* Hash output from command */ |
| entropy_estimate = hash_output_from_command(&entropy_sources[c], 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; |
| |
| /* Scale back estimates for subsequent passes through list */ |
| entropy_estimate /= SCALE_PER_RUN * (i + 1.0); |
| |
| /* Stir it in */ |
| RAND_add(hash, sizeof(hash), entropy_estimate); |
| |
| debug3("Got %0.2f bytes of entropy from '%s'", entropy_estimate, |
| entropy_sources[c].cmdstring); |
| |
| 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); |
| } else { |
| debug2("Command '%s' disabled (badness %d)", |
| entropy_sources[c].cmdstring, entropy_sources[c].badness); |
| |
| if (entropy_sources[c].badness > 0) |
| entropy_sources[c].badness--; |
| } |
| |
| 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) |
| { |
| #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 |
| _get_timeval_msec_difference(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_output_from_command(entropy_source_t *src, char *hash) |
| { |
| static int devnull = -1; |
| int p[2]; |
| fd_set rdset; |
| int cmd_eof = 0, error_abort = 0; |
| struct timeval tv_start, tv_current; |
| int msec_elapsed = 0; |
| pid_t pid; |
| int status; |
| char buf[16384]; |
| int bytes_read; |
| int total_bytes_read; |
| SHA_CTX sha; |
| |
| 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); |
| |
| setuid(original_uid); |
| 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); |
| total_bytes_read = 0; |
| |
| while (!error_abort && !cmd_eof) { |
| int ret; |
| struct timeval tv; |
| int msec_remaining; |
| |
| (void) gettimeofday(&tv_current, 0); |
| msec_elapsed = _get_timeval_msec_difference(&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; |
| break; |
| case 1: |
| /* command input */ |
| bytes_read = read(p[0], buf, sizeof(buf)); |
| 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); |
| } |
| |
| /* |
| * prng seedfile functions |
| */ |
| int |
| prng_check_seedfile(char *filename) { |
| |
| struct stat st; |
| |
| /* FIXME raceable: eg replace seed between this stat and subsequent open */ |
| /* Not such a problem because we don't trust the seed file anyway */ |
| if (lstat(filename, &st) == -1) { |
| /* Give up on hard errors */ |
| if (errno != ENOENT) |
| debug("WARNING: Couldn't stat random seed file \"%s\": %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 == original_uid)) { |
| debug("WARNING: PRNG seedfile %.100s must be mode 0600, owned by uid %d", |
| filename, getuid()); |
| return(0); |
| } |
| |
| return(1); |
| } |
| |
| void |
| prng_write_seedfile(void) { |
| int fd; |
| char seed[1024]; |
| char filename[1024]; |
| struct passwd *pw; |
| |
| /* Don't bother if we have already saved a seed */ |
| if (prng_seed_saved) |
| return; |
| |
| setuid(original_uid); |
| |
| prng_seed_saved = 1; |
| |
| pw = getpwuid(original_uid); |
| if (pw == NULL) |
| fatal("Couldn't get password entry for current user (%i): %s", |
| original_uid, strerror(errno)); |
| |
| /* Try to ensure that the parent directory is there */ |
| snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir, |
| SSH_USER_DIR); |
| mkdir(filename, 0700); |
| |
| snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir, |
| SSH_PRNG_SEED_FILE); |
| |
| debug("writing PRNG seed to file %.100s", filename); |
| |
| RAND_bytes(seed, sizeof(seed)); |
| |
| /* Don't care if the seed doesn't exist */ |
| prng_check_seedfile(filename); |
| |
| if ((fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0600)) == -1) { |
| debug("WARNING: couldn't access PRNG seedfile %.100s (%.100s)", |
| filename, strerror(errno)); |
| } else { |
| if (atomicio(write, fd, &seed, sizeof(seed)) != sizeof(seed)) |
| fatal("problem writing PRNG seedfile %.100s (%.100s)", filename, |
| strerror(errno)); |
| |
| close(fd); |
| } |
| } |
| |
| void |
| prng_read_seedfile(void) { |
| int fd; |
| char seed[1024]; |
| char filename[1024]; |
| struct passwd *pw; |
| |
| pw = getpwuid(original_uid); |
| if (pw == NULL) |
| fatal("Couldn't get password entry for current user (%i): %s", |
| original_uid, 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 not valid, 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) |
| { |
| FILE *f; |
| char *cp; |
| char line[1024]; |
| char cmd[1024]; |
| char path[256]; |
| int linenum; |
| int num_cmds = 64; |
| int cur_cmd = 0; |
| double est; |
| entropy_source_t *entcmd; |
| |
| f = fopen(cmdfilename, "r"); |
| if (!f) { |
| fatal("couldn't read entropy commands file %.100s: %.100s", |
| cmdfilename, strerror(errno)); |
| } |
| |
| entcmd = (entropy_source_t *)xmalloc(num_cmds * sizeof(entropy_source_t)); |
| memset(entcmd, '\0', num_cmds * sizeof(entropy_source_t)); |
| |
| /* Read in file */ |
| linenum = 0; |
| while (fgets(line, sizeof(line), f)) { |
| int arg; |
| char *argv; |
| |
| linenum++; |
| |
| /* skip leading whitespace, test for blank line or comment */ |
| cp = line + strspn(line, WHITESPACE); |
| if ((*cp == 0) || (*cp == '#')) |
| continue; /* done with this line */ |
| |
| /* First non-whitespace char should be double quote delimiting */ |
| /* 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, &argv); |
| |
| /* 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; |
| argv = NULL; |
| do { |
| char *s = (char*)xmalloc(strlen(cp) + 1); |
| strncpy(s, cp, strlen(cp) + 1); |
| entcmd[cur_cmd].args[arg] = s; |
| arg++; |
| } while ((arg < 5) && (cp = strtok(NULL, WHITESPACE))); |
| |
| if (strtok(NULL, WHITESPACE)) |
| error("ignored extra command elements (max 5), %.100s line %d", |
| 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_source_t)); |
| } |
| } |
| |
| /* zero the last entry */ |
| memset(&entcmd[cur_cmd], '\0', sizeof(entropy_source_t)); |
| |
| /* trim to size */ |
| entropy_sources = xrealloc(entcmd, (cur_cmd+1) * sizeof(entropy_source_t)); |
| |
| debug("Loaded %d entropy commands from %.100s", cur_cmd, cmdfilename); |
| |
| return (cur_cmd >= MIN_ENTROPY_SOURCES); |
| } |
| |
| /* |
| * Write a keyfile at exit |
| */ |
| void |
| prng_seed_cleanup(void *junk) |
| { |
| prng_write_seedfile(); |
| } |
| |
| /* |
| * Conditionally Seed OpenSSL's random number pool from |
| * syscalls and program output |
| */ |
| void |
| seed_rng(void) |
| { |
| void *old_sigchld_handler; |
| |
| if (!prng_initialised) |
| fatal("RNG not initialised"); |
| |
| /* Make sure some other sigchld handler doesn't reap our entropy */ |
| /* commands */ |
| old_sigchld_handler = signal(SIGCHLD, SIG_DFL); |
| |
| debug("Seeded RNG with %i bytes from programs", (int)stir_from_programs()); |
| debug("Seeded RNG with %i bytes from system calls", (int)stir_from_system()); |
| |
| if (!RAND_status()) |
| fatal("Not enough entropy in RNG"); |
| |
| signal(SIGCHLD, old_sigchld_handler); |
| |
| if (!RAND_status()) |
| fatal("Couldn't initialise builtin random number generator -- exiting."); |
| } |
| |
| void init_rng(void) |
| { |
| int original_euid; |
| |
| original_uid = getuid(); |
| original_euid = geteuid(); |
| |
| /* Read in collection commands */ |
| if (!prng_read_commands(SSH_PRNG_COMMAND_FILE)) |
| fatal("PRNG initialisation failed -- exiting."); |
| |
| /* Set ourselves up to save a seed upon exit */ |
| prng_seed_saved = 0; |
| |
| /* Give up privs while reading seed file */ |
| if ((original_uid != original_euid) && (seteuid(original_uid) == -1)) |
| fatal("Couldn't give up privileges"); |
| |
| prng_read_seedfile(); |
| |
| if ((original_uid != original_euid) && (seteuid(original_euid) == -1)) |
| fatal("Couldn't restore privileges"); |
| |
| fatal_add_cleanup(prng_seed_cleanup, NULL); |
| atexit(prng_write_seedfile); |
| |
| prng_initialised = 1; |
| } |
| |
| #endif /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */ |