diff options
Diffstat (limited to 'security/nss/lib/freebl/unix_rand.c')
| -rw-r--r-- | security/nss/lib/freebl/unix_rand.c | 811 |
1 files changed, 811 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 0000000000..e46bac6233 --- /dev/null +++ b/security/nss/lib/freebl/unix_rand.c @@ -0,0 +1,811 @@ +/* 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(_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 */ + +#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 + static const char *const files[] = { + "/etc/passwd", + "/etc/utmp", + "/tmp", + "/var/tmp", + "/usr/tmp", + 0 + }; + + 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; +} |