X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/fc8f52d72cb5d0296e85faf6fb834cd7bf10d7bf..318c3c31be343fdba362cb60f33aab3e88798d8a:/rand/noise.c diff --git a/rand/noise.c b/rand/noise.c index 7eb4c712..c120e6f2 100644 --- a/rand/noise.c +++ b/rand/noise.c @@ -29,10 +29,13 @@ #include "config.h" +#include #include +#include #include +#include #include -#include +#include #include #include @@ -45,7 +48,14 @@ # include #endif +#if defined(HAVE_LINUX_RANDOM_H) +# include +# include +#endif + #include +#include +#include #include #include "noise.h" @@ -55,7 +65,28 @@ /*----- Magical numbers ---------------------------------------------------*/ #define NOISE_KIDLIFE 100000 /* @noise_filter@ child lifetime */ -#define MILLION 1000000 /* One million */ + +#if HAVE_CLOCK_GETTIME && _POSIX_TIMERS > 0 +# define TIMESTRUCT timespec +# define tv_SEC tv_sec +# define tv_FRAC tv_nsec +# define TIMERES 1000000000 +# if _POSIX_MONOTONIC_CLOCK > 0 +# define GETTIME(tv) (clock_gettime(CLOCK_MONOTONIC, (tv))) +# else +# define GETTIME(tv) (clock_gettime(CLOCK_REALTIME, (tv))) +# endif +# define TOTIMEVAL(tv, xx) \ + ((tv)->tv_sec = (xx)->tv_sec, \ + (tv)->tv_usec = ((xx)->tv_nsec + 500)/1000) +#else +# define TIMESTRUCT timeval +# define tv_SEC tv_sec +# define tv_FRAC tv_usec +# define TIMERES 1000000 +# define GETTIME(tv) (gettimeofday((tv), 0)) +# define TOTIMEVAL(tv, xx) (*(tv) = *(xx)) +#endif /*----- Noise source definition -------------------------------------------*/ @@ -84,8 +115,8 @@ static gid_t noise_gid = NOISE_NOSETGID; /* Gid to set to spawn processes */ static int bitcount(unsigned long x) { - char ctab[] = { 0, 1, 1, 2, 1, 2, 2, 3, - 1, 2, 2, 3, 2, 3, 3, 4 }; + static const char ctab[] = { 0, 1, 1, 2, 1, 2, 2, 3, + 1, 2, 2, 3, 2, 3, 3, 4 }; int count = 0; while (x) { count += ctab[x & 0xfu]; @@ -97,20 +128,20 @@ static int bitcount(unsigned long x) /* --- @timer@ --- * * * Arguments: @rand_pool *r@ = pointer to randomness pool - * @struct timeval *tv@ = pointer to time block + * @const struct TIMESTRUCT *tv@ = pointer to time block * * Returns: Nonzero if some randomness was contributed. * * Use: Low-level timer contributor. */ -static int timer(rand_pool *r, struct timeval *tv) +static int timer(rand_pool *r, const struct TIMESTRUCT *tv) { unsigned long x, d, dd; int de, dde; int ret; - x = tv->tv_usec + MILLION * tv->tv_sec; + x = tv->tv_FRAC + TIMERES*tv->tv_SEC; d = x ^ noise_last; dd = d ^ noise_diff; noise_last = x; @@ -137,9 +168,8 @@ static int timer(rand_pool *r, struct timeval *tv) int noise_timer(rand_pool *r) { - struct timeval tv; - gettimeofday(&tv, 0); - return (timer(r, &tv)); + struct TIMESTRUCT tv; + GETTIME(&tv); return (timer(r, &tv)); } /* --- @noise_devrandom@ --- * @@ -154,11 +184,57 @@ int noise_timer(rand_pool *r) int noise_devrandom(rand_pool *r) { - int fd; + int fd = -1; octet buf[RAND_POOLSZ]; ssize_t len; size_t n = 0; int ret = 0; +#ifdef __linux__ + fd_set infd; + struct timeval tv = { 0, 0 }; +#endif +#ifdef HAVE_GETENTROPY + size_t nn; +#endif + +#if defined(HAVE_LINUX_RANDOM_H) && \ + defined(GRND_NONBLOCK) && \ + defined(SYS_getrandom) + /* --- Use the new shinies if available --- */ + + while (n < sizeof(buf)) { + if ((len = syscall(SYS_getrandom, buf + n, sizeof(buf) - n, + GRND_NONBLOCK)) <= 0) { + if (errno == ENOSYS) break; + else goto done; + } + n += len; + } + if (n == sizeof(buf)) goto win; +#endif + +#ifdef HAVE_GETENTROPY + /* --- OpenBSD-flavoured shinies --- */ + + while (n < sizeof(buf)) { + nn = sizeof(buf) - n; + if (nn > 256) nn = 256; + if (getentropy(buf + n, nn)) break; + n += nn; + } + if (n == sizeof(buf)) goto win; +#endif + +#ifdef __linux__ + /* --- Don't take from `/dev/urandom' if `/dev/random' would block --- */ + + if ((fd = open("/dev/random", O_RDONLY | O_NONBLOCK)) < 0) goto done; + FD_ZERO(&infd); + FD_SET(fd, &infd); + if (select(fd + 1, &infd, 0, 0, &tv) < 0 || !FD_ISSET(fd, &infd)) + goto done; + close(fd); fd = -1; +#endif /* --- Be nice to other clients of the random device --- * * @@ -168,18 +244,24 @@ int noise_devrandom(rand_pool *r) * needs to get some more entropy from somewhere. */ - if ((fd = open("/dev/urandom", O_RDONLY | O_NONBLOCK)) >= 0 || + if (fd >= 0 || + (fd = open("/dev/urandom", O_RDONLY | O_NONBLOCK)) >= 0 || (fd = open("/dev/arandom", O_RDONLY | O_NONBLOCK)) >= 0 || (fd = open("/dev/random", O_RDONLY | O_NONBLOCK)) >= 0) { while (n < sizeof(buf)) { if ((len = read(fd, buf + n, sizeof(buf) - n)) <= 0) break; n += len; } - rand_add(r, buf, n, n * 8); - BURN(buf); - if (n == sizeof(buf)) ret = 1; - close(fd); + if (n == sizeof(buf)) goto win; } + goto done; + +win: + ret = 1; +done: + if (fd >= 0) close(fd); + rand_add(r, buf, n, 8*n); + BURN(buf); noise_timer(r); return (ret); } @@ -226,13 +308,44 @@ void noise_setid(uid_t uid, gid_t gid) * This interface is Unix-specific. */ +struct noisekid { + rand_pool *r; + int good; + char buf[4096]; + int donep; + int ret; +}; + +static void kid_read(int fd, unsigned mode, void *p) +{ + struct noisekid *nk = p; + ssize_t sz; + int goodbits; + + noise_timer(nk->r); + if ((sz = read(fd, nk->buf, sizeof(nk->buf))) <= 0) + nk->donep = 1; + else { + goodbits = (sz * nk->good) / 128; + rand_add(nk->r, nk->buf, sz, goodbits); + nk->ret = 1; + } +} + +static void kid_dead(struct timeval *tv, void *p) + { struct noisekid *nk = p; nk->donep = 1; } + int noise_filter(rand_pool *r, int good, const char *c) { - char buf[4096]; pid_t kid; int fd[2]; struct timeval dead; + struct TIMESTRUCT now; int ret = 0; + struct noisekid nk = { 0 }; + sel_state sel; + sel_file sf; + sel_timer st; const char *env[] = { "PATH=/bin:/usr/bin:/sbin:/usr/sbin:/etc", 0 @@ -240,8 +353,8 @@ int noise_filter(rand_pool *r, int good, const char *c) /* --- Remember when this business started --- */ - gettimeofday(&dead, 0); - timer(r, &dead); + GETTIME(&now); timer(r, &now); + TOTIMEVAL(&dead, &now); /* --- Create a pipe --- */ @@ -261,78 +374,47 @@ int noise_filter(rand_pool *r, int good, const char *c) /* --- Handle the child end of the deal --- */ if (kid == 0) { - int f; + mdup_fd mfd[3]; + int f, i = 0; /* --- Set the pipe as standard output, close standard input --- */ - close(0); close(1); close(2); - - if (fd[1] != 1) { - if (dup2(fd[1], 1) < 0) _exit(127); - close(fd[1]); - } - - if ((f = open("/dev/null", O_RDONLY)) != 0 || - (f = open("/dev/null", O_WRONLY)) != 2) - _exit(127); + if ((f = open("/dev/null", O_RDONLY)) < 0) _exit(127); + mfd[i].cur = f; mfd[i].want = 0; i++; + mfd[i].cur = fd[1]; mfd[i].want = 1; i++; + mfd[i].cur = f; mfd[i].want = 2; i++; + if (mdup(mfd, i)) _exit(127); /* --- Play games with uids --- */ if (noise_gid != NOISE_NOSETGID) { - setgid(noise_gid); - setegid(noise_gid); + if (setgid(noise_gid) || setegid(noise_gid) #ifdef HAVE_SETGROUPS - setgroups(1, &noise_gid); + || setgroups(1, &noise_gid) #endif + ) _exit(127); } if (noise_uid != NOISE_NOSETUID) { - setuid(noise_uid); - seteuid(noise_uid); + if (setuid(noise_uid) || seteuid(noise_uid)) _exit(127); } /* --- Start the process up --- */ - execle("/bin/sh", "-c", c, (char *)0, env); + execle("/bin/sh", "sh", "-c", c, (char *)0, env); _exit(127); } /* --- Sort out my end of the deal --- */ close(fd[1]); - - /* --- Decide on the deadline --- */ - + sel_init(&sel); + nk.r = r; nk.good = good; TV_ADDL(&dead, &dead, 0, NOISE_KIDLIFE); - - /* --- Now read, and think --- */ - - for (;;) { - struct timeval now, diff; - fd_set rd; - - gettimeofday(&now, 0); - timer(r, &now); - if (TV_CMP(&now, >, &dead)) - break; - TV_SUB(&diff, &dead, &now); - - FD_ZERO(&rd); - FD_SET(fd[0], &rd); - - if (select(fd[0] + 1, &rd, 0, 0, &diff) < 0) - break; - if (FD_ISSET(fd[0], &rd)) { - ssize_t sz; - int goodbits; - - if ((sz = read(fd[0], buf, sizeof(buf))) <= 0) - break; - goodbits = (sz * good) / 128; - rand_add(r, buf, sz, goodbits); - ret = 1; - } - } + sel_initfile(&sel, &sf, fd[0], SEL_READ, kid_read, &nk); + sel_addfile(&sf); + sel_addtimer(&sel, &st, &dead, kid_dead, &nk); + while (!nk.donep && !sel_select(&sel)); /* --- We've finished with it: kill the child process --- * * @@ -342,11 +424,11 @@ int noise_filter(rand_pool *r, int good, const char *c) */ close(fd[0]); - BURN(buf); + BURN(nk.buf); noise_timer(r); kill(kid, SIGKILL); waitpid(kid, 0, 0); - return (ret); + return (nk.ret); } /* --- @noise_freewheel@ --- * @@ -362,7 +444,7 @@ int noise_filter(rand_pool *r, int good, const char *c) #ifdef USE_FREEWHEEL -static jmp_buf fwjmp; +static sigjmp_buf fwjmp; static void fwalarm(int sig) { @@ -453,7 +535,7 @@ void noise_acquire(rand_pool *r) unsigned i; for (i = 0; i < 8; i++) noise_freewheel(r); - if (!noise_devrandom(r)) { + if (!noise_devrandom(r) || getenv("CATACOMB_FORCE_ESOTERIC_SOURCES")) { noise_enquire(r); for (i = 0; i < 8; i++) noise_freewheel(r);