From 1acc058d0a7913838c830ed998a1a1fb5b7864bf Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Tue, 23 Feb 2016 16:12:13 +1100 Subject: Disable tests where fs perms are incorrect Some tests have strict requirements on the filesystem permissions for certain files and directories. This adds a regress/check-perm tool that copies the relevant logic from sshd to exactly test the paths in question. This lets us skip tests when the local filesystem doesn't conform to our expectations rather than continuing and failing the test run. ok dtucker@ --- regress/check-perm.c | 205 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 205 insertions(+) create mode 100644 regress/check-perm.c (limited to 'regress/check-perm.c') diff --git a/regress/check-perm.c b/regress/check-perm.c new file mode 100644 index 000000000..dac307d24 --- /dev/null +++ b/regress/check-perm.c @@ -0,0 +1,205 @@ +/* + * Placed in the public domain + */ + +/* $OpenBSD: modpipe.c,v 1.6 2013/11/21 03:16:47 djm Exp $ */ + +#include "includes.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#ifdef HAVE_LIBGEN_H +#include +#endif + +static void +fatal(const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + vfprintf(stderr, fmt, args); + fputc('\n', stderr); + va_end(args); + exit(1); +} +/* Based on session.c. NB. keep tests in sync */ +static void +safely_chroot(const char *path, uid_t uid) +{ + const char *cp; + char component[PATH_MAX]; + struct stat st; + + if (*path != '/') + fatal("chroot path does not begin at root"); + if (strlen(path) >= sizeof(component)) + fatal("chroot path too long"); + + /* + * Descend the path, checking that each component is a + * root-owned directory with strict permissions. + */ + for (cp = path; cp != NULL;) { + if ((cp = strchr(cp, '/')) == NULL) + strlcpy(component, path, sizeof(component)); + else { + cp++; + memcpy(component, path, cp - path); + component[cp - path] = '\0'; + } + + /* debug3("%s: checking '%s'", __func__, component); */ + + if (stat(component, &st) != 0) + fatal("%s: stat(\"%s\"): %s", __func__, + component, strerror(errno)); + if (st.st_uid != 0 || (st.st_mode & 022) != 0) + fatal("bad ownership or modes for chroot " + "directory %s\"%s\"", + cp == NULL ? "" : "component ", component); + if (!S_ISDIR(st.st_mode)) + fatal("chroot path %s\"%s\" is not a directory", + cp == NULL ? "" : "component ", component); + + } + + if (chdir(path) == -1) + fatal("Unable to chdir to chroot path \"%s\": " + "%s", path, strerror(errno)); +} + +/* from platform.c */ +int +platform_sys_dir_uid(uid_t uid) +{ + if (uid == 0) + return 1; +#ifdef PLATFORM_SYS_DIR_UID + if (uid == PLATFORM_SYS_DIR_UID) + return 1; +#endif + return 0; +} + +/* from auth.c */ +int +auth_secure_path(const char *name, struct stat *stp, const char *pw_dir, + uid_t uid, char *err, size_t errlen) +{ + char buf[PATH_MAX], homedir[PATH_MAX]; + char *cp; + int comparehome = 0; + struct stat st; + + if (realpath(name, buf) == NULL) { + snprintf(err, errlen, "realpath %s failed: %s", name, + strerror(errno)); + return -1; + } + if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) + comparehome = 1; + + if (!S_ISREG(stp->st_mode)) { + snprintf(err, errlen, "%s is not a regular file", buf); + return -1; + } + if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || + (stp->st_mode & 022) != 0) { + snprintf(err, errlen, "bad ownership or modes for file %s", + buf); + return -1; + } + + /* for each component of the canonical path, walking upwards */ + for (;;) { + if ((cp = dirname(buf)) == NULL) { + snprintf(err, errlen, "dirname() failed"); + return -1; + } + strlcpy(buf, cp, sizeof(buf)); + + if (stat(buf, &st) < 0 || + (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || + (st.st_mode & 022) != 0) { + snprintf(err, errlen, + "bad ownership or modes for directory %s", buf); + return -1; + } + + /* If are past the homedir then we can stop */ + if (comparehome && strcmp(homedir, buf) == 0) + break; + + /* + * dirname should always complete with a "/" path, + * but we can be paranoid and check for "." too + */ + if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) + break; + } + return 0; +} + +static void +usage(void) +{ + fprintf(stderr, "check-perm -m [chroot | keys-command] [path]\n"); + exit(1); +} + +int +main(int argc, char **argv) +{ + const char *path = "."; + char errmsg[256]; + int ch, mode = -1; + extern char *optarg; + extern int optind; + struct stat st; + + while ((ch = getopt(argc, argv, "hm:")) != -1) { + switch (ch) { + case 'm': + if (strcasecmp(optarg, "chroot") == 0) + mode = 1; + else if (strcasecmp(optarg, "keys-command") == 0) + mode = 2; + else { + fprintf(stderr, "Invalid -m option\n"), + usage(); + } + break; + default: + usage(); + } + } + argc -= optind; + argv += optind; + + if (argc > 1) + usage(); + else if (argc == 1) + path = argv[0]; + + if (mode == 1) + safely_chroot(path, getuid()); + else if (mode == 2) { + if (stat(path, &st) < 0) + fatal("Could not stat %s: %s", path, strerror(errno)); + if (auth_secure_path(path, &st, NULL, 0, + errmsg, sizeof(errmsg)) != 0) + fatal("Unsafe %s: %s", path, errmsg); + } else { + fprintf(stderr, "Invalid mode\n"); + usage(); + } + return 0; +} -- cgit v1.2.3