DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (237e4c0633fd)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898
/* 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__) || defined(__GNU__) || defined(__FreeBSD_kernel__) || defined(__NetBSD_kernel__)
#include <sys/times.h>

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>

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>

#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>

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>

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);

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>

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;
}

#ifdef DARWIN
#include <TargetConditionals.h>
#if !TARGET_OS_IPHONE
#include <crt_externs.h>
#endif
#endif

void
RNG_SystemInfoForRNG(void)
{
    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

    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));
    }

    /* grab some data from system's PRNG before any other files. */
    bytes = RNG_FileUpdate("/dev/urandom", SYSTEM_RNG_SEED_COUNT);
    if (!bytes) {
        PORT_SetError(SEC_ERROR_NEED_RANDOM);
    }

    /* 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);

#if defined(BSDI) || defined(FREEBSD) || defined(NETBSD) || defined(OPENBSD) || defined(DARWIN) || defined(LINUX) || defined(HPUX)
    if (bytes)
        return;
#endif

#ifdef SOLARIS
    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
}

#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);
}

#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;
}

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) {
        PORT_SetError(SEC_ERROR_NEED_RANDOM);
        return 0;
    }
    /* 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;
}