diff options
Diffstat (limited to 'security/nss/lib/freebl/unix_rand.c')
| -rw-r--r-- | security/nss/lib/freebl/unix_rand.c | 1176 |
1 files changed, 1176 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/unix_rand.c b/security/nss/lib/freebl/unix_rand.c new file mode 100644 index 000000000..ea3b6af3d --- /dev/null +++ b/security/nss/lib/freebl/unix_rand.c @@ -0,0 +1,1176 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include <stdio.h> +#include <string.h> +#include <signal.h> +#include <unistd.h> +#include <limits.h> +#include <errno.h> +#include <stdlib.h> +#include <sys/time.h> +#include <sys/wait.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <dirent.h> +#include "secrng.h" +#include "secerr.h" +#include "prerror.h" +#include "prthread.h" +#include "prprf.h" +#include "prenv.h" + +size_t RNG_FileUpdate(const char *fileName, size_t limit); + +/* + * When copying data to the buffer we want the least signicant bytes + * from the input since those bits are changing the fastest. The address + * of least significant byte depends upon whether we are running on + * a big-endian or little-endian machine. + * + * Does this mean the least signicant bytes are the most significant + * to us? :-) + */ + +static size_t +CopyLowBits(void *dst, size_t dstlen, void *src, size_t srclen) +{ + union endianness { + PRInt32 i; + char c[4]; + } u; + + if (srclen <= dstlen) { + memcpy(dst, src, srclen); + return srclen; + } + u.i = 0x01020304; + if (u.c[0] == 0x01) { + /* big-endian case */ + memcpy(dst, (char *)src + (srclen - dstlen), dstlen); + } else { + /* little-endian case */ + memcpy(dst, src, dstlen); + } + return dstlen; +} + +#ifdef SOLARIS + +#include <kstat.h> + +static const PRUint32 entropy_buf_len = 4096; /* buffer up to 4 KB */ + +/* Buffer entropy data, and feed it to the RNG, entropy_buf_len bytes at a time. + * Returns error if RNG_RandomUpdate fails. Also increments *total_fed + * by the number of bytes successfully buffered. + */ +static SECStatus +BufferEntropy(char *inbuf, PRUint32 inlen, + char *entropy_buf, PRUint32 *entropy_buffered, + PRUint32 *total_fed) +{ + PRUint32 tocopy = 0; + PRUint32 avail = 0; + SECStatus rv = SECSuccess; + + while (inlen) { + avail = entropy_buf_len - *entropy_buffered; + if (!avail) { + /* Buffer is full, time to feed it to the RNG. */ + rv = RNG_RandomUpdate(entropy_buf, entropy_buf_len); + if (SECSuccess != rv) { + break; + } + *entropy_buffered = 0; + avail = entropy_buf_len; + } + tocopy = PR_MIN(avail, inlen); + memcpy(entropy_buf + *entropy_buffered, inbuf, tocopy); + *entropy_buffered += tocopy; + inlen -= tocopy; + inbuf += tocopy; + *total_fed += tocopy; + } + return rv; +} + +/* Feed kernel statistics structures and ks_data field to the RNG. + * Returns status as well as the number of bytes successfully fed to the RNG. + */ +static SECStatus +RNG_kstat(PRUint32 *fed) +{ + kstat_ctl_t *kc = NULL; + kstat_t *ksp = NULL; + PRUint32 entropy_buffered = 0; + char *entropy_buf = NULL; + SECStatus rv = SECSuccess; + + PORT_Assert(fed); + if (!fed) { + return SECFailure; + } + *fed = 0; + + kc = kstat_open(); + PORT_Assert(kc); + if (!kc) { + return SECFailure; + } + entropy_buf = (char *)PORT_Alloc(entropy_buf_len); + PORT_Assert(entropy_buf); + if (entropy_buf) { + for (ksp = kc->kc_chain; ksp != NULL; ksp = ksp->ks_next) { + if (-1 == kstat_read(kc, ksp, NULL)) { + /* missing data from a single kstat shouldn't be fatal */ + continue; + } + rv = BufferEntropy((char *)ksp, sizeof(kstat_t), + entropy_buf, &entropy_buffered, + fed); + if (SECSuccess != rv) { + break; + } + + if (ksp->ks_data && ksp->ks_data_size > 0 && ksp->ks_ndata > 0) { + rv = BufferEntropy((char *)ksp->ks_data, ksp->ks_data_size, + entropy_buf, &entropy_buffered, + fed); + if (SECSuccess != rv) { + break; + } + } + } + if (SECSuccess == rv && entropy_buffered) { + /* Buffer is not empty, time to feed it to the RNG */ + rv = RNG_RandomUpdate(entropy_buf, entropy_buffered); + } + PORT_Free(entropy_buf); + } else { + rv = SECFailure; + } + if (kstat_close(kc)) { + PORT_Assert(0); + rv = SECFailure; + } + return rv; +} + +#endif + +#if defined(SCO) || defined(UNIXWARE) || defined(BSDI) || defined(FREEBSD) || defined(NETBSD) || defined(DARWIN) || defined(OPENBSD) || defined(NTO) || defined(__riscos__) +#include <sys/times.h> + +#define getdtablesize() sysconf(_SC_OPEN_MAX) + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + int ticks; + struct tms buffer; + + ticks = times(&buffer); + return CopyLowBits(buf, maxbytes, &ticks, sizeof(ticks)); +} + +static void +GiveSystemInfo(void) +{ + long si; + + /* + * Is this really necessary? Why not use rand48 or something? + */ + si = sysconf(_SC_CHILD_MAX); + RNG_RandomUpdate(&si, sizeof(si)); + + si = sysconf(_SC_STREAM_MAX); + RNG_RandomUpdate(&si, sizeof(si)); + + si = sysconf(_SC_OPEN_MAX); + RNG_RandomUpdate(&si, sizeof(si)); +} +#endif + +#if defined(__sun) +#if defined(__svr4) || defined(SVR4) +#include <sys/systeminfo.h> + +#define getdtablesize() sysconf(_SC_OPEN_MAX) + +static void +GiveSystemInfo(void) +{ + int rv; + char buf[2000]; + + rv = sysinfo(SI_MACHINE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_RELEASE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_HW_SERIAL, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } +} + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + hrtime_t t; + t = gethrtime(); + if (t) { + return CopyLowBits(buf, maxbytes, &t, sizeof(t)); + } + return 0; +} +#else /* SunOS (Sun, but not SVR4) */ + +extern long sysconf(int name); + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + return 0; +} + +static void +GiveSystemInfo(void) +{ + long si; + + /* This is not very good */ + si = sysconf(_SC_CHILD_MAX); + RNG_RandomUpdate(&si, sizeof(si)); +} +#endif +#endif /* Sun */ + +#if defined(__hpux) +#include <sys/unistd.h> + +#define getdtablesize() sysconf(_SC_OPEN_MAX) + +#if defined(__ia64) +#include <ia64/sys/inline.h> + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + PRUint64 t; + + t = _Asm_mov_from_ar(_AREG44); + return CopyLowBits(buf, maxbytes, &t, sizeof(t)); +} +#else +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + extern int ret_cr16(); + int cr16val; + + cr16val = ret_cr16(); + return CopyLowBits(buf, maxbytes, &cr16val, sizeof(cr16val)); +} +#endif + +static void +GiveSystemInfo(void) +{ + long si; + + /* This is not very good */ + si = sysconf(_AES_OS_VERSION); + RNG_RandomUpdate(&si, sizeof(si)); + si = sysconf(_SC_CPU_VERSION); + RNG_RandomUpdate(&si, sizeof(si)); +} +#endif /* HPUX */ + +#if defined(OSF1) +#include <sys/types.h> +#include <sys/sysinfo.h> +#include <sys/systeminfo.h> +#include <c_asm.h> + +static void +GiveSystemInfo(void) +{ + char buf[BUFSIZ]; + int rv; + int off = 0; + + rv = sysinfo(SI_MACHINE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_RELEASE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_HW_SERIAL, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } +} + +/* + * Use the "get the cycle counter" instruction on the alpha. + * The low 32 bits completely turn over in less than a minute. + * The high 32 bits are some non-counter gunk that changes sometimes. + */ +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + unsigned long t; + + t = asm("rpcc %v0"); + return CopyLowBits(buf, maxbytes, &t, sizeof(t)); +} + +#endif /* Alpha */ + +#if defined(_IBMR2) +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + return 0; +} + +static void +GiveSystemInfo(void) +{ + /* XXX haven't found any yet! */ +} +#endif /* IBM R2 */ + +#if defined(LINUX) +#include <sys/sysinfo.h> + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + return 0; +} + +static void +GiveSystemInfo(void) +{ +#ifndef NO_SYSINFO + struct sysinfo si; + if (sysinfo(&si) == 0) { + RNG_RandomUpdate(&si, sizeof(si)); + } +#endif +} +#endif /* LINUX */ + +#if defined(NCR) + +#include <sys/utsname.h> +#include <sys/systeminfo.h> + +#define getdtablesize() sysconf(_SC_OPEN_MAX) + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + return 0; +} + +static void +GiveSystemInfo(void) +{ + int rv; + char buf[2000]; + + rv = sysinfo(SI_MACHINE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_RELEASE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_HW_SERIAL, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } +} + +#endif /* NCR */ + +#if defined(sgi) +#include <fcntl.h> +#undef PRIVATE +#include <sys/mman.h> +#include <sys/syssgi.h> +#include <sys/immu.h> +#include <sys/systeminfo.h> +#include <sys/utsname.h> +#include <wait.h> + +static void +GiveSystemInfo(void) +{ + int rv; + char buf[4096]; + + rv = syssgi(SGI_SYSID, &buf[0]); + if (rv > 0) { + RNG_RandomUpdate(buf, MAXSYSIDSIZE); + } +#ifdef SGI_RDUBLK + rv = syssgi(SGI_RDUBLK, getpid(), &buf[0], sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, sizeof(buf)); + } +#endif /* SGI_RDUBLK */ + rv = syssgi(SGI_INVENT, SGI_INV_READ, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, sizeof(buf)); + } + rv = sysinfo(SI_MACHINE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_RELEASE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_HW_SERIAL, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } +} + +static size_t +GetHighResClock(void *buf, size_t maxbuf) +{ + unsigned phys_addr, raddr, cycleval; + static volatile unsigned *iotimer_addr = NULL; + static int tries = 0; + static int cntr_size; + int mfd; + long s0[2]; + struct timeval tv; + +#ifndef SGI_CYCLECNTR_SIZE +#define SGI_CYCLECNTR_SIZE 165 /* Size user needs to use to read CC */ +#endif + + if (iotimer_addr == NULL) { + if (tries++ > 1) { + /* Don't keep trying if it didn't work */ + return 0; + } + + /* + ** For SGI machines we can use the cycle counter, if it has one, + ** to generate some truly random numbers + */ + phys_addr = syssgi(SGI_QUERY_CYCLECNTR, &cycleval); + if (phys_addr) { + int pgsz = getpagesize(); + int pgoffmask = pgsz - 1; + + raddr = phys_addr & ~pgoffmask; + mfd = open("/dev/mmem", O_RDONLY); + if (mfd < 0) { + return 0; + } + iotimer_addr = (unsigned *) + mmap(0, pgoffmask, PROT_READ, MAP_PRIVATE, mfd, (int)raddr); + if (iotimer_addr == (void *)-1) { + close(mfd); + iotimer_addr = NULL; + return 0; + } + iotimer_addr = (unsigned *)((__psint_t)iotimer_addr | (phys_addr & pgoffmask)); + /* + * The file 'mfd' is purposefully not closed. + */ + cntr_size = syssgi(SGI_CYCLECNTR_SIZE); + if (cntr_size < 0) { + struct utsname utsinfo; + + /* + * We must be executing on a 6.0 or earlier system, since the + * SGI_CYCLECNTR_SIZE call is not supported. + * + * The only pre-6.1 platforms with 64-bit counters are + * IP19 and IP21 (Challenge, PowerChallenge, Onyx). + */ + uname(&utsinfo); + if (!strncmp(utsinfo.machine, "IP19", 4) || + !strncmp(utsinfo.machine, "IP21", 4)) + cntr_size = 64; + else + cntr_size = 32; + } + cntr_size /= 8; /* Convert from bits to bytes */ + } + } + + s0[0] = *iotimer_addr; + if (cntr_size > 4) + s0[1] = *(iotimer_addr + 1); + memcpy(buf, (char *)&s0[0], cntr_size); + return CopyLowBits(buf, maxbuf, &s0, cntr_size); +} +#endif + +#if defined(sony) +#include <sys/systeminfo.h> + +#define getdtablesize() sysconf(_SC_OPEN_MAX) + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + return 0; +} + +static void +GiveSystemInfo(void) +{ + int rv; + char buf[2000]; + + rv = sysinfo(SI_MACHINE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_RELEASE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_HW_SERIAL, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } +} +#endif /* sony */ + +#if defined(sinix) +#include <sys/systeminfo.h> +#include <sys/times.h> + +int gettimeofday(struct timeval *, struct timezone *); +int gethostname(char *, int); + +#define getdtablesize() sysconf(_SC_OPEN_MAX) + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + int ticks; + struct tms buffer; + + ticks = times(&buffer); + return CopyLowBits(buf, maxbytes, &ticks, sizeof(ticks)); +} + +static void +GiveSystemInfo(void) +{ + int rv; + char buf[2000]; + + rv = sysinfo(SI_MACHINE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_RELEASE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_HW_SERIAL, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } +} +#endif /* sinix */ + +#ifdef BEOS +#include <be/kernel/OS.h> + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + bigtime_t bigtime; /* Actually a int64 */ + + bigtime = real_time_clock_usecs(); + return CopyLowBits(buf, maxbytes, &bigtime, sizeof(bigtime)); +} + +static void +GiveSystemInfo(void) +{ + system_info *info = NULL; + PRInt32 val; + get_system_info(info); + if (info) { + val = info->boot_time; + RNG_RandomUpdate(&val, sizeof(val)); + val = info->used_pages; + RNG_RandomUpdate(&val, sizeof(val)); + val = info->used_ports; + RNG_RandomUpdate(&val, sizeof(val)); + val = info->used_threads; + RNG_RandomUpdate(&val, sizeof(val)); + val = info->used_teams; + RNG_RandomUpdate(&val, sizeof(val)); + } +} +#endif /* BEOS */ + +#if defined(nec_ews) +#include <sys/systeminfo.h> + +#define getdtablesize() sysconf(_SC_OPEN_MAX) + +static size_t +GetHighResClock(void *buf, size_t maxbytes) +{ + return 0; +} + +static void +GiveSystemInfo(void) +{ + int rv; + char buf[2000]; + + rv = sysinfo(SI_MACHINE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_RELEASE, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } + rv = sysinfo(SI_HW_SERIAL, buf, sizeof(buf)); + if (rv > 0) { + RNG_RandomUpdate(buf, rv); + } +} +#endif /* nec_ews */ + +size_t +RNG_GetNoise(void *buf, size_t maxbytes) +{ + struct timeval tv; + int n = 0; + int c; + + n = GetHighResClock(buf, maxbytes); + maxbytes -= n; + + (void)gettimeofday(&tv, 0); + c = CopyLowBits((char *)buf + n, maxbytes, &tv.tv_usec, sizeof(tv.tv_usec)); + n += c; + maxbytes -= c; + c = CopyLowBits((char *)buf + n, maxbytes, &tv.tv_sec, sizeof(tv.tv_sec)); + n += c; + return n; +} + +#define SAFE_POPEN_MAXARGS 10 /* must be at least 2 */ + +/* + * safe_popen is static to this module and we know what arguments it is + * called with. Note that this version only supports a single open child + * process at any time. + */ +static pid_t safe_popen_pid; +static struct sigaction oldact; + +static FILE * +safe_popen(char *cmd) +{ + int p[2], fd, argc; + pid_t pid; + char *argv[SAFE_POPEN_MAXARGS + 1]; + FILE *fp; + static char blank[] = " \t"; + static struct sigaction newact; + + if (pipe(p) < 0) + return 0; + + fp = fdopen(p[0], "r"); + if (fp == 0) { + close(p[0]); + close(p[1]); + return 0; + } + + /* Setup signals so that SIGCHLD is ignored as we want to do waitpid */ + newact.sa_handler = SIG_DFL; + newact.sa_flags = 0; + sigfillset(&newact.sa_mask); + sigaction(SIGCHLD, &newact, &oldact); + + pid = fork(); + switch (pid) { + int ndesc; + + case -1: + fclose(fp); /* this closes p[0], the fd associated with fp */ + close(p[1]); + sigaction(SIGCHLD, &oldact, NULL); + return 0; + + case 0: + /* dup write-side of pipe to stderr and stdout */ + if (p[1] != 1) + dup2(p[1], 1); + if (p[1] != 2) + dup2(p[1], 2); + + /* + * close the other file descriptors, except stdin which we + * try reassociating with /dev/null, first (bug 174993) + */ + if (!freopen("/dev/null", "r", stdin)) + close(0); + ndesc = getdtablesize(); + for (fd = PR_MIN(65536, ndesc); --fd > 2; close(fd)) + ; + + /* clean up environment in the child process */ + putenv("PATH=/bin:/usr/bin:/sbin:/usr/sbin:/etc:/usr/etc"); + putenv("SHELL=/bin/sh"); + putenv("IFS= \t"); + + /* + * The caller may have passed us a string that is in text + * space. It may be illegal to modify the string + */ + cmd = strdup(cmd); + /* format argv */ + argv[0] = strtok(cmd, blank); + argc = 1; + while ((argv[argc] = strtok(0, blank)) != 0) { + if (++argc == SAFE_POPEN_MAXARGS) { + argv[argc] = 0; + break; + } + } + + /* and away we go */ + execvp(argv[0], argv); + exit(127); + break; + + default: + close(p[1]); + break; + } + + /* non-zero means there's a cmd running */ + safe_popen_pid = pid; + return fp; +} + +static int +safe_pclose(FILE *fp) +{ + pid_t pid; + int status = -1, rv; + + if ((pid = safe_popen_pid) == 0) + return -1; + safe_popen_pid = 0; + + fclose(fp); + + /* yield the processor so the child gets some time to exit normally */ + PR_Sleep(PR_INTERVAL_NO_WAIT); + + /* if the child hasn't exited, kill it -- we're done with its output */ + while ((rv = waitpid(pid, &status, WNOHANG)) == -1 && errno == EINTR) + ; + if (rv == 0) { + kill(pid, SIGKILL); + while ((rv = waitpid(pid, &status, 0)) == -1 && errno == EINTR) + ; + } + + /* Reset SIGCHLD signal hander before returning */ + sigaction(SIGCHLD, &oldact, NULL); + + return status; +} + +#ifdef DARWIN +#include <TargetConditionals.h> +#if !TARGET_OS_IPHONE +#include <crt_externs.h> +#endif +#endif + +/* Fork netstat to collect its output by default. Do not unset this unless + * another source of entropy is available + */ +#define DO_NETSTAT 1 + +void +RNG_SystemInfoForRNG(void) +{ + FILE *fp; + char buf[BUFSIZ]; + size_t bytes; + const char *const *cp; + char *randfile; +#ifdef DARWIN +#if TARGET_OS_IPHONE + /* iOS does not expose a way to access environ. */ + char **environ = NULL; +#else + char **environ = *_NSGetEnviron(); +#endif +#else + extern char **environ; +#endif +#ifdef BEOS + static const char *const files[] = { + "/boot/var/swap", + "/boot/var/log/syslog", + "/boot/var/tmp", + "/boot/home/config/settings", + "/boot/home", + 0 + }; +#else + static const char *const files[] = { + "/etc/passwd", + "/etc/utmp", + "/tmp", + "/var/tmp", + "/usr/tmp", + 0 + }; +#endif + +#if defined(BSDI) + static char netstat_ni_cmd[] = "netstat -nis"; +#else + static char netstat_ni_cmd[] = "netstat -ni"; +#endif + + GiveSystemInfo(); + + bytes = RNG_GetNoise(buf, sizeof(buf)); + RNG_RandomUpdate(buf, bytes); + + /* + * Pass the C environment and the addresses of the pointers to the + * hash function. This makes the random number function depend on the + * execution environment of the user and on the platform the program + * is running on. + */ + if (environ != NULL) { + cp = (const char *const *)environ; + while (*cp) { + RNG_RandomUpdate(*cp, strlen(*cp)); + cp++; + } + RNG_RandomUpdate(environ, (char *)cp - (char *)environ); + } + + /* Give in system information */ + if (gethostname(buf, sizeof(buf)) == 0) { + RNG_RandomUpdate(buf, strlen(buf)); + } + GiveSystemInfo(); + + /* grab some data from system's PRNG before any other files. */ + bytes = RNG_FileUpdate("/dev/urandom", SYSTEM_RNG_SEED_COUNT); + + /* If the user points us to a random file, pass it through the rng */ + randfile = PR_GetEnvSecure("NSRANDFILE"); + if ((randfile != NULL) && (randfile[0] != '\0')) { + char *randCountString = PR_GetEnvSecure("NSRANDCOUNT"); + int randCount = randCountString ? atoi(randCountString) : 0; + if (randCount != 0) { + RNG_FileUpdate(randfile, randCount); + } else { + RNG_FileForRNG(randfile); + } + } + + /* pass other files through */ + for (cp = files; *cp; cp++) + RNG_FileForRNG(*cp); + +/* + * Bug 100447: On BSD/OS 4.2 and 4.3, we have problem calling safe_popen + * in a pthreads environment. Therefore, we call safe_popen last and on + * BSD/OS we do not call safe_popen when we succeeded in getting data + * from /dev/urandom. + * + * Bug 174993: On platforms providing /dev/urandom, don't fork netstat + * either, if data has been gathered successfully. + */ + +#if defined(BSDI) || defined(FREEBSD) || defined(NETBSD) || defined(OPENBSD) || defined(DARWIN) || defined(LINUX) || defined(HPUX) + if (bytes) + return; +#endif + +#ifdef SOLARIS + +/* + * On Solaris, NSS may be initialized automatically from libldap in + * applications that are unaware of the use of NSS. safe_popen forks, and + * sometimes creates issues with some applications' pthread_atfork handlers. + * We always have /dev/urandom on Solaris 9 and above as an entropy source, + * and for Solaris 8 we have the libkstat interface, so we don't need to + * fork netstat. + */ + +#undef DO_NETSTAT + if (!bytes) { + /* On Solaris 8, /dev/urandom isn't available, so we use libkstat. */ + PRUint32 kstat_bytes = 0; + if (SECSuccess != RNG_kstat(&kstat_bytes)) { + PORT_Assert(0); + } + bytes += kstat_bytes; + PORT_Assert(bytes); + } +#endif + +#ifdef DO_NETSTAT + fp = safe_popen(netstat_ni_cmd); + if (fp != NULL) { + while ((bytes = fread(buf, 1, sizeof(buf), fp)) > 0) + RNG_RandomUpdate(buf, bytes); + safe_pclose(fp); + } +#endif +} + +#define TOTAL_FILE_LIMIT 1000000 /* one million */ + +size_t +RNG_FileUpdate(const char *fileName, size_t limit) +{ + FILE *file; + int fd; + int bytes; + size_t fileBytes = 0; + struct stat stat_buf; + unsigned char buffer[BUFSIZ]; + static size_t totalFileBytes = 0; + + /* suppress valgrind warnings due to holes in struct stat */ + memset(&stat_buf, 0, sizeof(stat_buf)); + + if (stat((char *)fileName, &stat_buf) < 0) + return fileBytes; + RNG_RandomUpdate(&stat_buf, sizeof(stat_buf)); + + file = fopen(fileName, "r"); + if (file != NULL) { + /* Read from the underlying file descriptor directly to bypass stdio + * buffering and avoid reading more bytes than we need from + * /dev/urandom. NOTE: we can't use fread with unbuffered I/O because + * fread may return EOF in unbuffered I/O mode on Android. + * + * Moreover, we read into a buffer of size BUFSIZ, so buffered I/O + * has no performance advantage. */ + fd = fileno(file); + /* 'file' was just opened, so this should not fail. */ + PORT_Assert(fd != -1); + while (limit > fileBytes && fd != -1) { + bytes = PR_MIN(sizeof buffer, limit - fileBytes); + bytes = read(fd, buffer, bytes); + if (bytes <= 0) + break; + RNG_RandomUpdate(buffer, bytes); + fileBytes += bytes; + totalFileBytes += bytes; + /* after TOTAL_FILE_LIMIT has been reached, only read in first + ** buffer of data from each subsequent file. + */ + if (totalFileBytes > TOTAL_FILE_LIMIT) + break; + } + fclose(file); + } + /* + * Pass yet another snapshot of our highest resolution clock into + * the hash function. + */ + bytes = RNG_GetNoise(buffer, sizeof(buffer)); + RNG_RandomUpdate(buffer, bytes); + return fileBytes; +} + +void +RNG_FileForRNG(const char *fileName) +{ + RNG_FileUpdate(fileName, TOTAL_FILE_LIMIT); +} + +void +ReadSingleFile(const char *fileName) +{ + FILE *file; + unsigned char buffer[BUFSIZ]; + + file = fopen(fileName, "rb"); + if (file != NULL) { + while (fread(buffer, 1, sizeof(buffer), file) > 0) + ; + fclose(file); + } +} + +#define _POSIX_PTHREAD_SEMANTICS +#include <dirent.h> + +PRBool +ReadFileOK(char *dir, char *file) +{ + struct stat stat_buf; + char filename[PATH_MAX]; + int count = snprintf(filename, sizeof filename, "%s/%s", dir, file); + + if (count <= 0) { + return PR_FALSE; /* name too long, can't read it anyway */ + } + + if (stat(filename, &stat_buf) < 0) + return PR_FALSE; /* can't stat, probably can't read it then as well */ + return S_ISREG(stat_buf.st_mode) ? PR_TRUE : PR_FALSE; +} + +/* + * read one file out of either /etc or the user's home directory. + * fileToRead tells which file to read. + * + * return 1 if it's time to reset the fileToRead (no more files to read). + */ +static int +ReadOneFile(int fileToRead) +{ + char *dir = "/etc"; + DIR *fd = opendir(dir); + int resetCount = 0; + struct dirent *entry; +#if defined(__sun) + char firstName[256]; +#else + char firstName[NAME_MAX + 1]; +#endif + const char *name = NULL; + int i; + + if (fd == NULL) { + dir = PR_GetEnvSecure("HOME"); + if (dir) { + fd = opendir(dir); + } + } + if (fd == NULL) { + return 1; + } + + firstName[0] = '\0'; + for (i = 0; i <= fileToRead; i++) { + do { + /* readdir() isn't guaranteed to be thread safe on every platform; + * this code assumes the same directory isn't read concurrently. + * This usage is confirmed safe on Linux, see bug 1254334. */ + entry = readdir(fd); + } while (entry != NULL && !ReadFileOK(dir, &entry->d_name[0])); + if (entry == NULL) { + resetCount = 1; /* read to the end, start again at the beginning */ + if (firstName[0]) { + /* ran out of entries in the directory, use the first one */ + name = firstName; + } + break; + } + name = entry->d_name; + if (i == 0) { + /* copy the name of the first in case we run out of entries */ + PORT_Assert(PORT_Strlen(name) < sizeof(firstName)); + PORT_Strncpy(firstName, name, sizeof(firstName) - 1); + firstName[sizeof(firstName) - 1] = '\0'; + } + } + + if (name) { + char filename[PATH_MAX]; + int count = snprintf(filename, sizeof(filename), "%s/%s", dir, name); + if (count >= 1) { + ReadSingleFile(filename); + } + } + + closedir(fd); + return resetCount; +} + +/* + * do something to try to introduce more noise into the 'GetNoise' call + */ +static void +rng_systemJitter(void) +{ + static int fileToRead = 1; + + if (ReadOneFile(fileToRead)) { + fileToRead = 1; + } else { + fileToRead++; + } +} + +size_t +RNG_SystemRNG(void *dest, size_t maxLen) +{ + FILE *file; + int fd; + int bytes; + size_t fileBytes = 0; + unsigned char *buffer = dest; + + file = fopen("/dev/urandom", "r"); + if (file == NULL) { + return rng_systemFromNoise(dest, maxLen); + } + /* Read from the underlying file descriptor directly to bypass stdio + * buffering and avoid reading more bytes than we need from /dev/urandom. + * NOTE: we can't use fread with unbuffered I/O because fread may return + * EOF in unbuffered I/O mode on Android. + */ + fd = fileno(file); + /* 'file' was just opened, so this should not fail. */ + PORT_Assert(fd != -1); + while (maxLen > fileBytes && fd != -1) { + bytes = maxLen - fileBytes; + bytes = read(fd, buffer, bytes); + if (bytes <= 0) + break; + fileBytes += bytes; + buffer += bytes; + } + fclose(file); + if (fileBytes != maxLen) { + PORT_SetError(SEC_ERROR_NEED_RANDOM); /* system RNG failed */ + fileBytes = 0; + } + return fileBytes; +} |