From 042761cdd0ee5f76ecd62ee1e9ae984cfbcda8e1 Mon Sep 17 00:00:00 2001 From: djm Date: Thu, 5 May 2011 03:48:37 +0000 Subject: - (djm) [Makefile.in WARNING.RNG aclocal.m4 buildpkg.sh.in configure.ac] [entropy.c ssh-add.c ssh-agent.c ssh-keygen.c ssh-keyscan.c] [ssh-keysign.c ssh-pkcs11-helper.c ssh-rand-helper.8 ssh-rand-helper.c] [ssh.c ssh_prng_cmds.in sshd.c contrib/aix/buildbff.sh] [regress/README.regress] Remove ssh-rand-helper and all its tentacles. PRNGd seeding has been rolled into entropy.c directly. Thanks to tim@ for testing on affected platforms. --- entropy.c | 238 ++++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 139 insertions(+), 99 deletions(-) (limited to 'entropy.c') diff --git a/entropy.c b/entropy.c index a8216625..2d6d3ec5 100644 --- a/entropy.c +++ b/entropy.c @@ -25,19 +25,19 @@ #include "includes.h" #include -#include - -#ifdef HAVE_SYS_STAT_H -# include +#include +#ifdef HAVE_SYS_UN_H +# include #endif -#ifdef HAVE_FCNTL_H -# include -#endif -#include -#include +#include +#include + +#include #include +#include #include +#include /* for offsetof */ #include #include @@ -54,118 +54,128 @@ /* * Portable OpenSSH PRNG seeding: * If OpenSSL has not "internally seeded" itself (e.g. pulled data from - * /dev/random), then we execute a "ssh-rand-helper" program which - * collects entropy and writes it to stdout. The child program must - * write at least RANDOM_SEED_SIZE bytes. The child is run with stderr - * attached, so error/debugging output should be visible. - * - * XXX: we should tell the child how many bytes we need. + * /dev/random), then collect RANDOM_SEED_SIZE bytes of randomness from + * PRNGd. */ - #ifndef OPENSSL_PRNG_ONLY + #define RANDOM_SEED_SIZE 48 -static uid_t original_uid, original_euid; -#endif -void -seed_rng(void) +/* + * Collect 'len' bytes of entropy into 'buf' from PRNGD/EGD daemon + * listening either on 'tcp_port', or via Unix domain socket at * + * 'socket_path'. + * Either a non-zero tcp_port or a non-null socket_path must be + * supplied. + * Returns 0 on success, -1 on error + */ +int +get_random_bytes_prngd(unsigned char *buf, int len, + unsigned short tcp_port, char *socket_path) { -#ifndef OPENSSL_PRNG_ONLY - int devnull; - int p[2]; - pid_t pid; - int ret; - unsigned char buf[RANDOM_SEED_SIZE]; - mysig_t old_sigchld; + int fd, addr_len, rval, errors; + u_char msg[2]; + struct sockaddr_storage addr; + struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr; + struct sockaddr_un *addr_un = (struct sockaddr_un *)&addr; + mysig_t old_sigpipe; + + /* Sanity checks */ + if (socket_path == NULL && tcp_port == 0) + fatal("You must specify a port or a socket"); + if (socket_path != NULL && + strlen(socket_path) >= sizeof(addr_un->sun_path)) + fatal("Random pool path is too long"); + if (len <= 0 || len > 255) + fatal("Too many bytes (%d) to read from PRNGD", len); + + memset(&addr, '\0', sizeof(addr)); + + if (tcp_port != 0) { + addr_in->sin_family = AF_INET; + addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK); + addr_in->sin_port = htons(tcp_port); + addr_len = sizeof(*addr_in); + } else { + addr_un->sun_family = AF_UNIX; + strlcpy(addr_un->sun_path, socket_path, + sizeof(addr_un->sun_path)); + addr_len = offsetof(struct sockaddr_un, sun_path) + + strlen(socket_path) + 1; + } - if (RAND_status() == 1) { - debug3("RNG is ready, skipping seeding"); - return; + old_sigpipe = mysignal(SIGPIPE, SIG_IGN); + + errors = 0; + rval = -1; +reopen: + fd = socket(addr.ss_family, SOCK_STREAM, 0); + if (fd == -1) { + error("Couldn't create socket: %s", strerror(errno)); + goto done; } - debug3("Seeding PRNG from %s", SSH_RAND_HELPER); - - if ((devnull = open("/dev/null", O_RDWR)) == -1) - fatal("Couldn't open /dev/null: %s", strerror(errno)); - if (pipe(p) == -1) - fatal("pipe: %s", strerror(errno)); - - old_sigchld = signal(SIGCHLD, SIG_DFL); - if ((pid = fork()) == -1) - fatal("Couldn't fork: %s", strerror(errno)); - if (pid == 0) { - dup2(devnull, STDIN_FILENO); - dup2(p[1], STDOUT_FILENO); - /* Keep stderr open for errors */ - close(p[0]); - close(p[1]); - close(devnull); - - if (original_uid != original_euid && - ( seteuid(getuid()) == -1 || - setuid(original_uid) == -1) ) { - fprintf(stderr, "(rand child) setuid(%li): %s\n", - (long int)original_uid, strerror(errno)); - _exit(1); + if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) { + if (tcp_port != 0) { + error("Couldn't connect to PRNGD port %d: %s", + tcp_port, strerror(errno)); + } else { + error("Couldn't connect to PRNGD socket \"%s\": %s", + addr_un->sun_path, strerror(errno)); } - - execl(SSH_RAND_HELPER, "ssh-rand-helper", NULL); - fprintf(stderr, "(rand child) Couldn't exec '%s': %s\n", - SSH_RAND_HELPER, strerror(errno)); - _exit(1); + goto done; } - close(devnull); - close(p[1]); + /* Send blocking read request to PRNGD */ + msg[0] = 0x02; + msg[1] = len; - memset(buf, '\0', sizeof(buf)); - ret = atomicio(read, p[0], buf, sizeof(buf)); - if (ret == -1) - fatal("Couldn't read from ssh-rand-helper: %s", + if (atomicio(vwrite, fd, msg, sizeof(msg)) != sizeof(msg)) { + if (errno == EPIPE && errors < 10) { + close(fd); + errors++; + goto reopen; + } + error("Couldn't write to PRNGD socket: %s", strerror(errno)); - if (ret != sizeof(buf)) - fatal("ssh-rand-helper child produced insufficient data"); - - close(p[0]); + goto done; + } - if (waitpid(pid, &ret, 0) == -1) - fatal("Couldn't wait for ssh-rand-helper completion: %s", + if (atomicio(read, fd, buf, len) != (size_t)len) { + if (errno == EPIPE && errors < 10) { + close(fd); + errors++; + goto reopen; + } + error("Couldn't read from PRNGD socket: %s", strerror(errno)); - signal(SIGCHLD, old_sigchld); - - /* We don't mind if the child exits upon a SIGPIPE */ - if (!WIFEXITED(ret) && - (!WIFSIGNALED(ret) || WTERMSIG(ret) != SIGPIPE)) - fatal("ssh-rand-helper terminated abnormally"); - if (WEXITSTATUS(ret) != 0) - fatal("ssh-rand-helper exit with exit status %d", ret); - - RAND_add(buf, sizeof(buf), sizeof(buf)); - memset(buf, '\0', sizeof(buf)); + goto done; + } -#endif /* OPENSSL_PRNG_ONLY */ - if (RAND_status() != 1) - fatal("PRNG is not seeded"); + rval = 0; +done: + mysignal(SIGPIPE, old_sigpipe); + if (fd != -1) + close(fd); + return rval; } -void -init_rng(void) +static int +seed_from_prngd(unsigned char *buf, size_t bytes) { - /* - * OpenSSL version numbers: MNNFFPPS: major minor fix patch status - * We match major, minor, fix and status (not patch) - */ - if ((SSLeay() ^ OPENSSL_VERSION_NUMBER) & ~0xff0L) - fatal("OpenSSL version mismatch. Built against %lx, you " - "have %lx", (u_long)OPENSSL_VERSION_NUMBER, SSLeay()); - -#ifndef OPENSSL_PRNG_ONLY - original_uid = getuid(); - original_euid = geteuid(); +#ifdef PRNGD_PORT + debug("trying egd/prngd port %d", PRNGD_PORT); + if (get_random_bytes_prngd(buf, bytes, PRNGD_PORT, NULL) == 0) + return 0; +#endif +#ifdef PRNGD_SOCKET + debug("trying egd/prngd socket %s", PRNGD_SOCKET); + if (get_random_bytes_prngd(buf, bytes, 0, PRNGD_SOCKET) == 0) + return 0; #endif + return -1; } -#ifndef OPENSSL_PRNG_ONLY void rexec_send_rng_seed(Buffer *m) { @@ -191,4 +201,34 @@ rexec_recv_rng_seed(Buffer *m) RAND_add(buf, len, len); } } +#endif /* OPENSSL_PRNG_ONLY */ + +void +seed_rng(void) +{ +#ifndef OPENSSL_PRNG_ONLY + unsigned char buf[RANDOM_SEED_SIZE]; #endif + /* + * OpenSSL version numbers: MNNFFPPS: major minor fix patch status + * We match major, minor, fix and status (not patch) + */ + if ((SSLeay() ^ OPENSSL_VERSION_NUMBER) & ~0xff0L) + fatal("OpenSSL version mismatch. Built against %lx, you " + "have %lx", (u_long)OPENSSL_VERSION_NUMBER, SSLeay()); + +#ifndef OPENSSL_PRNG_ONLY + if (RAND_status() == 1) { + debug3("RNG is ready, skipping seeding"); + return; + } + + if (seed_from_prngd(buf, sizeof(buf)) == -1) + fatal("Could not obtain seed from PRNGd"); + RAND_add(buf, sizeof(buf), sizeof(buf)); + memset(buf, '\0', sizeof(buf)); + +#endif /* OPENSSL_PRNG_ONLY */ + if (RAND_status() != 1) + fatal("PRNG is not seeded"); +} -- cgit v1.2.1