/* $OpenBSD: misc.c,v 1.67 2008/01/01 08:47:04 dtucker Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2005,2006 Damien Miller. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_PATHS_H # include #include #endif #ifdef SSH_TUN_OPENBSD #include #endif #include "xmalloc.h" #include "misc.h" #include "log.h" #include "ssh.h" #define UNUSED(expr) do { (void)(expr); } while (0) /* remove newline at end of string */ char * pamsshagentauth_chop(char *s) { char *t = s; while (*t) { if (*t == '\n' || *t == '\r') { *t = '\0'; return s; } t++; } return s; } /* set/unset filedescriptor to non-blocking */ int pamsshagentauth_set_nonblock(int fd) { int val; val = fcntl(fd, F_GETFL, 0); if (val < 0) { pamsshagentauth_logerror("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno)); return (-1); } if (val & O_NONBLOCK) { pamsshagentauth_verbose("fd %d is O_NONBLOCK", fd); return (0); } pamsshagentauth_verbose("fd %d setting O_NONBLOCK", fd); val |= O_NONBLOCK; if (fcntl(fd, F_SETFL, val) == -1) { pamsshagentauth_verbose("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, strerror(errno)); return (-1); } return (0); } int pamsshagentauth_unset_nonblock(int fd) { int val; val = fcntl(fd, F_GETFL, 0); if (val < 0) { pamsshagentauth_logerror("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno)); return (-1); } if (!(val & O_NONBLOCK)) { pamsshagentauth_verbose("fd %d is not O_NONBLOCK", fd); return (0); } pamsshagentauth_verbose("fd %d clearing O_NONBLOCK", fd); val &= ~O_NONBLOCK; if (fcntl(fd, F_SETFL, val) == -1) { pamsshagentauth_verbose("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", fd, strerror(errno)); return (-1); } return (0); } const char * ssh_gai_strerror(int gaierr) { if (gaierr == EAI_SYSTEM) return strerror(errno); return gai_strerror(gaierr); } /* disable nagle on socket */ void pamsshagentauth_set_nodelay(int fd) { int opt; socklen_t optlen; optlen = sizeof opt; if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { pamsshagentauth_verbose("getsockopt TCP_NODELAY: %.100s", strerror(errno)); return; } if (opt == 1) { pamsshagentauth_verbose("fd %d is TCP_NODELAY", fd); return; } opt = 1; pamsshagentauth_verbose("fd %d setting TCP_NODELAY", fd); if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) pamsshagentauth_logerror("setsockopt TCP_NODELAY: %.100s", strerror(errno)); } /* Characters considered whitespace in strsep calls. */ #define WHITESPACE " \t\r\n" #define QUOTE "\"" /* return next token in configuration line */ char * pamsshagentauth_strdelim(char **s) { char *old; int wspace = 0; if (*s == NULL) return NULL; old = *s; *s = strpbrk(*s, WHITESPACE QUOTE "="); if (*s == NULL) return (old); if (*s[0] == '\"') { memmove(*s, *s + 1, strlen(*s)); /* move nul too */ /* Find matching quote */ if ((*s = strpbrk(*s, QUOTE)) == NULL) { return (NULL); /* no matching quote */ } else { *s[0] = '\0'; return (old); } } /* Allow only one '=' to be skipped */ if (*s[0] == '=') wspace = 1; *s[0] = '\0'; /* Skip any extra whitespace after first token */ *s += strspn(*s + 1, WHITESPACE) + 1; if (*s[0] == '=' && !wspace) *s += strspn(*s + 1, WHITESPACE) + 1; return (old); } struct passwd * pamsshagentauth_pwcopy(struct passwd *pw) { struct passwd *copy = pamsshagentauth_xcalloc(1, sizeof(*copy)); copy->pw_name = pamsshagentauth_xstrdup(pw->pw_name); copy->pw_passwd = pamsshagentauth_xstrdup(pw->pw_passwd); copy->pw_gecos = pamsshagentauth_xstrdup(pw->pw_gecos); copy->pw_uid = pw->pw_uid; copy->pw_gid = pw->pw_gid; #ifdef HAVE_PW_EXPIRE_IN_PASSWD copy->pw_expire = pw->pw_expire; #endif #ifdef HAVE_PW_CHANGE_IN_PASSWD copy->pw_change = pw->pw_change; #endif #ifdef HAVE_PW_CLASS_IN_PASSWD copy->pw_class = pamsshagentauth_xstrdup(pw->pw_class); #endif copy->pw_dir = pamsshagentauth_xstrdup(pw->pw_dir); copy->pw_shell = pamsshagentauth_xstrdup(pw->pw_shell); return copy; } /* * Convert ASCII string to TCP/IP port number. * Port must be >0 and <=65535. * Return 0 if invalid. */ int pamsshagentauth_a2port(const char *s) { long port; char *endp; errno = 0; port = strtol(s, &endp, 0); if (s == endp || *endp != '\0' || (errno == ERANGE && (port == LONG_MIN || port == LONG_MAX)) || port <= 0 || port > 65535) return 0; return port; } int pamsshagentauth_a2tun(const char *s, int *remote) { const char *errstr = NULL; char *sp, *ep; int tun; if (remote != NULL) { *remote = SSH_TUNID_ANY; sp = pamsshagentauth_xstrdup(s); if ((ep = strchr(sp, ':')) == NULL) { pamsshagentauth_xfree(sp); return (pamsshagentauth_a2tun(s, NULL)); } ep[0] = '\0'; ep++; *remote = pamsshagentauth_a2tun(ep, NULL); tun = pamsshagentauth_a2tun(sp, NULL); pamsshagentauth_xfree(sp); return (*remote == SSH_TUNID_ERR ? *remote : tun); } if (strcasecmp(s, "any") == 0) return (SSH_TUNID_ANY); tun = pamsshagentauth_strtonum(s, 0, SSH_TUNID_MAX, &errstr); if (errstr != NULL) return (SSH_TUNID_ERR); return (tun); } #define SECONDS 1 #define MINUTES (SECONDS * 60) #define HOURS (MINUTES * 60) #define DAYS (HOURS * 24) #define WEEKS (DAYS * 7) /* * Convert a time string into seconds; format is * a sequence of: * time[qualifier] * * Valid time qualifiers are: * seconds * s|S seconds * m|M minutes * h|H hours * d|D days * w|W weeks * * Examples: * 90m 90 minutes * 1h30m 90 minutes * 2d 2 days * 1w 1 week * * Return -1 if time string is invalid. */ long pamsshagentauth_convtime(const char *s) { long total, secs; const char *p; char *endp; errno = 0; total = 0; p = s; if (p == NULL || *p == '\0') return -1; while (*p) { secs = strtol(p, &endp, 10); if (p == endp || (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) || secs < 0) return -1; switch (*endp++) { case '\0': endp--; break; case 's': case 'S': break; case 'm': case 'M': secs *= MINUTES; break; case 'h': case 'H': secs *= HOURS; break; case 'd': case 'D': secs *= DAYS; break; case 'w': case 'W': secs *= WEEKS; break; default: return -1; } total += secs; if (total < 0) return -1; p = endp; } return total; } /* * Returns a standardized host+port identifier string. * Caller must free returned string. */ char * pamsshagentauth_put_host_port(const char *host, u_short port) { char *hoststr; if (port == 0 || port == SSH_DEFAULT_PORT) return(pamsshagentauth_xstrdup(host)); if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0) pamsshagentauth_fatal("put_host_port: asprintf: %s", strerror(errno)); pamsshagentauth_verbose("put_host_port: %s", hoststr); return hoststr; } /* * Search for next delimiter between hostnames/addresses and ports. * Argument may be modified (for termination). * Returns *cp if parsing succeeds. * *cp is set to the start of the next delimiter, if one was found. * If this is the last field, *cp is set to NULL. */ char * pamsshagentauth_hpdelim(char **cp) { char *s, *old; if (cp == NULL || *cp == NULL) return NULL; old = s = *cp; if (*s == '[') { if ((s = strchr(s, ']')) == NULL) return NULL; else s++; } else if ((s = strpbrk(s, ":/")) == NULL) s = *cp + strlen(*cp); /* skip to end (see first case below) */ switch (*s) { case '\0': *cp = NULL; /* no more fields*/ break; case ':': case '/': *s = '\0'; /* terminate */ *cp = s + 1; break; default: return NULL; } return old; } char * pamsshagentauth_cleanhostname(char *host) { if (*host == '[' && host[strlen(host) - 1] == ']') { host[strlen(host) - 1] = '\0'; return (host + 1); } else return host; } char * pamsshagentauth_colon(char *cp) { int flag = 0; if (*cp == ':') /* Leading colon is part of file name. */ return (0); if (*cp == '[') flag = 1; for (; *cp; ++cp) { if (*cp == '@' && *(cp+1) == '[') flag = 1; if (*cp == ']' && *(cp+1) == ':' && flag) return (cp+1); if (*cp == ':' && !flag) return (cp); if (*cp == '/') return (0); } return (0); } /* function to assist building execv() arguments */ void pamsshagentauth_addargs(arglist *args, char *fmt, ...) { va_list ap; char *cp; u_int nalloc; int r; va_start(ap, fmt); r = vasprintf(&cp, fmt, ap); va_end(ap); if (r == -1) pamsshagentauth_fatal("addargs: argument too long"); nalloc = args->nalloc; if (args->list == NULL) { nalloc = 32; args->num = 0; } else if (args->num+2 >= nalloc) nalloc *= 2; args->list = pamsshagentauth_xrealloc(args->list, nalloc, sizeof(char *)); args->nalloc = nalloc; args->list[args->num++] = cp; args->list[args->num] = NULL; } void pamsshagentauth_replacearg(arglist *args, u_int which, char *fmt, ...) { va_list ap; char *cp; int r; va_start(ap, fmt); r = vasprintf(&cp, fmt, ap); va_end(ap); if (r == -1) pamsshagentauth_fatal("replacearg: argument too long"); if (which >= args->num) pamsshagentauth_fatal("replacearg: tried to replace invalid arg %d >= %d", which, args->num); pamsshagentauth_xfree(args->list[which]); args->list[which] = cp; } void pamsshagentauth_freeargs(arglist *args) { u_int i; if (args->list != NULL) { for (i = 0; i < args->num; i++) pamsshagentauth_xfree(args->list[i]); pamsshagentauth_xfree(args->list); args->nalloc = args->num = 0; args->list = NULL; } } /* * Expands tildes in the file name. Returns data allocated by xmalloc. * Warning: this calls getpw*. */ char * pamsshagentauth_tilde_expand_filename(const char *filename, uid_t uid) { const char *path; char user[128], ret[MAXPATHLEN]; struct passwd *pw; u_int len, slash; if (*filename != '~') return (pamsshagentauth_xstrdup(filename)); filename++; path = strchr(filename, '/'); if (path != NULL && path > filename) { /* ~user/path */ slash = path - filename; if (slash > sizeof(user) - 1) pamsshagentauth_fatal("tilde_expand_filename: ~username too long"); memcpy(user, filename, slash); user[slash] = '\0'; if ((pw = getpwnam(user)) == NULL) pamsshagentauth_fatal("tilde_expand_filename: No such user %s", user); } else if ((pw = getpwuid(uid)) == NULL) /* ~/path */ pamsshagentauth_fatal("tilde_expand_filename: No such uid %lu", (unsigned long) uid); if (pamsshagentauth_strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret)) pamsshagentauth_fatal("tilde_expand_filename: Path too long"); /* Make sure directory has a trailing '/' */ len = strlen(pw->pw_dir); if ((len == 0 || pw->pw_dir[len - 1] != '/') && pamsshagentauth_strlcat(ret, "/", sizeof(ret)) >= sizeof(ret)) pamsshagentauth_fatal("tilde_expand_filename: Path too long"); /* Skip leading '/' from specified path */ if (path != NULL) filename = path + 1; if (pamsshagentauth_strlcat(ret, filename, sizeof(ret)) >= sizeof(ret)) pamsshagentauth_fatal("tilde_expand_filename: Path too long"); return (pamsshagentauth_xstrdup(ret)); } /* * Expand a string with a set of %[char] escapes. A number of escapes may be * specified as (char *escape_chars, char *replacement) pairs. The list must * be terminated by a NULL escape_char. Returns replaced string in memory * allocated by xmalloc. */ char * pamsshagentauth_percent_expand(const char *string, ...) { #define EXPAND_MAX_KEYS 16 struct { const char *key; const char *repl; } keys[EXPAND_MAX_KEYS]; u_int num_keys, i, j; char buf[4096]; va_list ap; /* Gather keys */ va_start(ap, string); for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { keys[num_keys].key = va_arg(ap, char *); if (keys[num_keys].key == NULL) break; keys[num_keys].repl = va_arg(ap, char *); if (keys[num_keys].repl == NULL) pamsshagentauth_fatal("percent_expand: NULL replacement"); } va_end(ap); if (num_keys >= EXPAND_MAX_KEYS) pamsshagentauth_fatal("percent_expand: too many keys"); /* Expand string */ *buf = '\0'; for (i = 0; *string != '\0'; string++) { if (*string != '%') { append: buf[i++] = *string; if (i >= sizeof(buf)) pamsshagentauth_fatal("percent_expand: string too long"); buf[i] = '\0'; continue; } string++; if (*string == '%') goto append; for (j = 0; j < num_keys; j++) { if (strchr(keys[j].key, *string) != NULL) { i = pamsshagentauth_strlcat(buf, keys[j].repl, sizeof(buf)); if (i >= sizeof(buf)) pamsshagentauth_fatal("percent_expand: string too long"); break; } } if (j >= num_keys) pamsshagentauth_fatal("percent_expand: unknown key %%%c", *string); } return (pamsshagentauth_xstrdup(buf)); #undef EXPAND_MAX_KEYS } /* * Read an entire line from a public key file into a static buffer, discarding * lines that exceed the buffer size. Returns 0 on success, -1 on failure. */ int read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz, u_long *lineno) { while (fgets(buf, bufsz, f) != NULL) { if (buf[0] == '\0') continue; (*lineno)++; if (buf[strlen(buf) - 1] == '\n' || feof(f)) { return 0; } else { pamsshagentauth_verbose("%s: %s line %lu exceeds size limit", __func__, filename, *lineno); /* discard remainder of line */ while (fgetc(f) != '\n' && !feof(f)) ; /* nothing */ } } return -1; } int pamsshagentauth_tun_open(int tun, int mode) { #if defined(CUSTOM_SYS_TUN_OPEN) return (sys_tun_open(tun, mode)); #elif defined(SSH_TUN_OPENBSD) struct ifreq ifr; char name[100]; int fd = -1, sock; /* Open the tunnel device */ if (tun <= SSH_TUNID_MAX) { snprintf(name, sizeof(name), "/dev/tun%d", tun); fd = open(name, O_RDWR); } else if (tun == SSH_TUNID_ANY) { for (tun = 100; tun >= 0; tun--) { snprintf(name, sizeof(name), "/dev/tun%d", tun); if ((fd = open(name, O_RDWR)) >= 0) break; } } else { pamsshagentauth_verbose("%s: invalid tunnel %u", __func__, tun); return (-1); } if (fd < 0) { pamsshagentauth_verbose("%s: %s open failed: %s", __func__, name, strerror(errno)); return (-1); } pamsshagentauth_verbose("%s: %s mode %d fd %d", __func__, name, mode, fd); /* Set the tunnel device operation mode */ snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun); if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) goto failed; if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) goto failed; /* Set interface mode */ ifr.ifr_flags &= ~IFF_UP; if (mode == SSH_TUNMODE_ETHERNET) ifr.ifr_flags |= IFF_LINK0; else ifr.ifr_flags &= ~IFF_LINK0; if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) goto failed; /* Bring interface up */ ifr.ifr_flags |= IFF_UP; if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) goto failed; close(sock); return (fd); failed: if (fd >= 0) close(fd); if (sock >= 0) close(sock); pamsshagentauth_verbose("%s: failed to set %s mode %d: %s", __func__, name, mode, strerror(errno)); return (-1); #else UNUSED(tun); UNUSED(mode); pamsshagentauth_logerror("Tunnel interfaces are not supported on this platform"); return (-1); #endif } void pamsshagentauth_sanitise_stdfd(void) { int nullfd, dupfd; if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno)); exit(1); } while (++dupfd <= 2) { /* Only clobber closed fds */ if (fcntl(dupfd, F_GETFL, 0) >= 0) continue; if (dup2(nullfd, dupfd) == -1) { fprintf(stderr, "dup2: %s", strerror(errno)); exit(1); } } if (nullfd > 2) close(nullfd); } char * pamsshagentauth_tohex(const void *vp, size_t l) { const u_char *p = (const u_char *)vp; char b[3], *r; size_t i, hl; if (l > 65536) return pamsshagentauth_xstrdup("tohex: length > 65536"); hl = l * 2 + 1; r = pamsshagentauth_xcalloc(1, hl); for (i = 0; i < l; i++) { snprintf(b, sizeof(b), "%02x", p[i]); pamsshagentauth_strlcat(r, b, hl); } return (r); } u_int64_t pamsshagentauth_get_u64(const void *vp) { const u_char *p = (const u_char *)vp; u_int64_t v; v = (u_int64_t)p[0] << 56; v |= (u_int64_t)p[1] << 48; v |= (u_int64_t)p[2] << 40; v |= (u_int64_t)p[3] << 32; v |= (u_int64_t)p[4] << 24; v |= (u_int64_t)p[5] << 16; v |= (u_int64_t)p[6] << 8; v |= (u_int64_t)p[7]; return (v); } u_int32_t pamsshagentauth_get_u32(const void *vp) { const u_char *p = (const u_char *)vp; u_int32_t v; v = (u_int32_t)p[0] << 24; v |= (u_int32_t)p[1] << 16; v |= (u_int32_t)p[2] << 8; v |= (u_int32_t)p[3]; return (v); } u_int16_t pamsshagentauth_get_u16(const void *vp) { const u_char *p = (const u_char *)vp; u_int16_t v; v = (u_int16_t)p[0] << 8; v |= (u_int16_t)p[1]; return (v); } void pamsshagentauth_put_u64(void *vp, u_int64_t v) { u_char *p = (u_char *)vp; p[0] = (u_char)(v >> 56) & 0xff; p[1] = (u_char)(v >> 48) & 0xff; p[2] = (u_char)(v >> 40) & 0xff; p[3] = (u_char)(v >> 32) & 0xff; p[4] = (u_char)(v >> 24) & 0xff; p[5] = (u_char)(v >> 16) & 0xff; p[6] = (u_char)(v >> 8) & 0xff; p[7] = (u_char)v & 0xff; } void pamsshagentauth_put_u32(void *vp, u_int32_t v) { u_char *p = (u_char *)vp; p[0] = (u_char)(v >> 24) & 0xff; p[1] = (u_char)(v >> 16) & 0xff; p[2] = (u_char)(v >> 8) & 0xff; p[3] = (u_char)v & 0xff; } void pamsshagentauth_put_u16(void *vp, u_int16_t v) { u_char *p = (u_char *)vp; p[0] = (u_char)(v >> 8) & 0xff; p[1] = (u_char)v & 0xff; }