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Fix pkgfs stat so it satisfies libsecureboot

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We need a valid st_dev, st_ino and st_mtime
to correctly track which files have been verified
and to update our notion of time.

ve_utc_set(): ignore utc if it would jump our current time
by more than VE_UTC_MAX_JUMP (20 years).

Allow testing of install command via userboot.
Need to fix its stat implementation too.

bhyveload also needs stat fixed - due to change to userboot.h

Call ve_error_get() from vectx_close() when hash is wrong.

Track the names of files we have hashed into pcr

For the purposes of measured boot, it is important
to be able to reproduce the hash reflected in
loader.ve.pcr
so loader.ve.hashed provides a list of names in the order they
were added.

Reviewed by:	imp
MFC after:	1 week
Sponsored by:	Juniper Networks
Differential Revision:	https://reviews.freebsd.org//D24027
This commit is contained in:
Simon J. Gerraty 2020-03-25 19:12:19 +00:00
parent 7c63520c42
commit 53f151f906
13 changed files with 184 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
lib/libsecureboot/h/libsecureboot.h
View File

@ -78,10 +78,11 @@ unsigned char *verify_sig(const char *, int);
unsigned char *verify_asc(const char *, int); /* OpenPGP */
void ve_pcr_init(void);
void ve_pcr_update(unsigned char *, size_t);
void ve_pcr_update(const char *, unsigned char *, size_t);
ssize_t ve_pcr_get(unsigned char *, size_t);
int ve_pcr_updating_get(void);
void ve_pcr_updating_set(int);
char * ve_pcr_hashed_get(int);
/* flags for verify_{asc,sig,signed} */
#define VEF_VERBOSE 1

24
lib/libsecureboot/vectx.c
View File

@ -104,8 +104,8 @@ vectx_open(int fd, const char *path, off_t off, struct stat *stp,
rc = verify_prep(fd, path, off, stp, __func__);
DEBUG_PRINTF(2,
("vectx_open: caller=%s,name='%s',prep_rc=%d\n",
caller,path, rc));
("vectx_open: caller=%s,fd=%d,name='%s',prep_rc=%d\n",
caller, fd, path, rc));
switch (rc) {
case VE_FINGERPRINT_NONE:
@ -316,6 +316,9 @@ vectx_lseek(struct vectx *ctx, off_t off, int whence)
* We have finished reading file, compare the hash with what
* we wanted.
*
* Be sure to call this before closing the file, since we may
* need to seek to the end to ensure hashing is complete.
*
* @param[in] pctx
* pointer to ctx
*
@ -337,20 +340,25 @@ vectx_close(struct vectx *ctx, int severity, const char *caller)
*/
ve_pcr_updating_set((severity == VE_MUST));
#endif
/* make sure we have hashed it all */
vectx_lseek(ctx, 0, SEEK_END);
rc = ve_check_hash(&ctx->vec_ctx, ctx->vec_md,
ctx->vec_path, ctx->vec_want, ctx->vec_hashsz);
}
DEBUG_PRINTF(2,
("vectx_close: caller=%s,name='%s',rc=%d,severity=%d\n",
caller,ctx->vec_path, rc, severity));
if (severity > VE_WANT || rc == VE_FINGERPRINT_WRONG)
if (rc == VE_FINGERPRINT_WRONG) {
printf("Unverified: %s\n", ve_error_get());
#if !defined(UNIT_TEST) && !defined(DEBUG_VECTX)
/* we are generally called with VE_MUST */
if (severity > VE_WANT)
panic("cannot continue");
#endif
} else if (severity > VE_WANT) {
printf("%serified %s\n", (rc <= 0) ? "Unv" : "V",
ctx->vec_path);
#if !defined(UNIT_TEST) && !defined(DEBUG_VECTX)
/* we are generally called with VE_MUST */
if (severity > VE_WANT && rc == VE_FINGERPRINT_WRONG)
panic("cannot continue");
#endif
}
free(ctx);
return ((rc < 0) ? rc : 0);
}

8
lib/libsecureboot/veopen.c
View File

@ -86,9 +86,11 @@ fingerprint_info_add(const char *filename, const char *prefix,
}
nfip->fi_prefix = strdup(filename);
cp = strrchr(nfip->fi_prefix, '/');
if (cp)
if (cp == nfip->fi_prefix) {
cp[1] = '\0';
} else if (cp) {
*cp = '\0';
else {
} else {
free(nfip->fi_prefix);
free(nfip);
return;
@ -96,7 +98,7 @@ fingerprint_info_add(const char *filename, const char *prefix,
}
/* collapse any trailing ..[/] */
n = 0;
while ((cp = strrchr(nfip->fi_prefix, '/')) != NULL) {
while ((cp = strrchr(nfip->fi_prefix, '/')) > nfip->fi_prefix) {
if (cp[1] == '\0') { /* trailing "/" */
*cp = '\0';
continue;

79
lib/libsecureboot/vepcr.c
View File

@ -25,6 +25,7 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/queue.h>
#include "libsecureboot-priv.h"
/*
@ -43,7 +44,16 @@ __FBSDID("$FreeBSD$");
static const br_hash_class *pcr_md = NULL;
static br_hash_compat_context pcr_ctx;
static size_t pcr_hlen = 0;
static int pcr_updating;
static int pcr_updating = -1;
struct hashed_info {
const char *hi_path;
const char *hi_basename;
STAILQ_ENTRY(hashed_info) entries;
};
static STAILQ_HEAD(, hashed_info) hi_list;
/**
* @brief initialize pcr context
@ -54,10 +64,13 @@ static int pcr_updating;
void
ve_pcr_init(void)
{
pcr_updating = 0;
pcr_hlen = br_sha256_SIZE;
pcr_md = &br_sha256_vtable;
pcr_md->init(&pcr_ctx.vtable);
if (pcr_updating < 0) {
pcr_updating = 0;
pcr_hlen = br_sha256_SIZE;
pcr_md = &br_sha256_vtable;
pcr_md->init(&pcr_ctx.vtable);
STAILQ_INIT(&hi_list);
}
}
/**
@ -82,10 +95,28 @@ ve_pcr_updating_set(int updating)
* @brief update pcr context
*/
void
ve_pcr_update(unsigned char *data, size_t dlen)
ve_pcr_update(const char *path, unsigned char *data, size_t dlen)
{
if (pcr_updating != 0 && pcr_md != NULL)
struct hashed_info *hip;
if (pcr_updating > 0 && pcr_md != NULL) {
pcr_md->update(&pcr_ctx.vtable, data, dlen);
/* if mallocs fail, measured boot will likely fail too */
if ((hip = malloc(sizeof(struct hashed_info)))) {
hip->hi_path = strdup(path);
if (!hip->hi_path) {
free(hip);
return;
}
hip->hi_basename = strrchr(hip->hi_path, '/');
if (hip->hi_basename) {
hip->hi_basename++;
} else {
hip->hi_basename = hip->hi_path;
}
STAILQ_INSERT_TAIL(&hi_list, hip, entries);
}
}
}
/**
@ -102,3 +133,37 @@ ve_pcr_get(unsigned char *buf, size_t sz)
return (pcr_hlen);
}
/**
* @brief get list of paths in prc
*/
char *
ve_pcr_hashed_get(int flags)
{
const char *cp;
char *hinfo;
struct hashed_info *hip;
size_t nbytes;
size_t x;
int n;
n = 0;
nbytes = x = 0;
hinfo = NULL;
STAILQ_FOREACH(hip, &hi_list, entries) {
nbytes += 1 + strlen(flags ? hip->hi_basename : hip->hi_path);
}
if (nbytes > 1) {
hinfo = malloc(nbytes + 2);
if (hinfo) {
STAILQ_FOREACH(hip, &hi_list, entries) {
cp = flags ? hip->hi_basename : hip->hi_path;
n = snprintf(&hinfo[x], nbytes - x, "%s,", cp);
x += n;
}
if (x > 0) {
hinfo[x-1] = '\0';
}
}
}
return hinfo;
}

26
lib/libsecureboot/verify_file.c
View File

@ -117,10 +117,12 @@ is_verified(struct stat *stp)
{
struct verify_status *vsp;
for (vsp = verified_files; vsp != NULL; vsp = vsp->vs_next) {
if (stp->st_dev == vsp->vs_dev &&
stp->st_ino == vsp->vs_ino)
return (vsp->vs_status);
if (stp->st_ino > 0) {
for (vsp = verified_files; vsp != NULL; vsp = vsp->vs_next) {
if (stp->st_dev == vsp->vs_dev &&
stp->st_ino == vsp->vs_ino)
return (vsp->vs_status);
}
}
return (VE_NOT_CHECKED);
}
@ -367,10 +369,11 @@ verify_prep(int fd, const char *filename, off_t off, struct stat *stp,
return (0);
}
DEBUG_PRINTF(2,
("caller=%s,fd=%d,name='%s',off=%lld,dev=%lld,ino=%lld\n",
("verify_prep: caller=%s,fd=%d,name='%s',off=%lld,dev=%lld,ino=%lld\n",
caller, fd, filename, (long long)off, (long long)stp->st_dev,
(long long)stp->st_ino));
rc = is_verified(stp);
DEBUG_PRINTF(4,("verify_prep: is_verified()->%d\n", rc));
if (rc == VE_NOT_CHECKED) {
rc = find_manifest(filename);
} else {
@ -458,7 +461,6 @@ verify_file(int fd, const char *filename, off_t off, int severity,
#endif
}
if (severity < VE_MUST) { /* not a kernel or module */
if ((cp = strrchr(filename, '/'))) {
cp++;
if (strncmp(cp, "loader.ve.", 10) == 0) {
@ -511,6 +513,7 @@ verify_pcr_export(void)
#ifdef VE_PCR_SUPPORT
char hexbuf[br_sha256_SIZE * 2 + 2];
unsigned char hbuf[br_sha256_SIZE];
char *hinfo;
char *hex;
ssize_t hlen;
@ -520,6 +523,17 @@ verify_pcr_export(void)
if (hex) {
hex[hlen*2] = '\0'; /* clobber newline */
setenv("loader.ve.pcr", hex, 1);
DEBUG_PRINTF(1,
("%s: setenv(loader.ve.pcr, %s\n", __func__,
hex));
hinfo = ve_pcr_hashed_get(1);
if (hinfo) {
setenv("loader.ve.hashed", hinfo, 1);
DEBUG_PRINTF(1,
("%s: setenv(loader.ve.hashed, %s\n",
__func__, hinfo));
free(hinfo);
}
}
}
#endif

16
lib/libsecureboot/vets.c
View File

@ -44,6 +44,10 @@ __FBSDID("$FreeBSD$");
#endif
#define SECONDS_PER_DAY 86400
#define SECONDS_PER_YEAR 365 * SECONDS_PER_DAY
#ifndef VE_UTC_MAX_JUMP
# define VE_UTC_MAX_JUMP 20 * SECONDS_PER_YEAR
#endif
#define X509_DAYS_TO_UTC0 719528
int DebugVe = 0;
@ -113,12 +117,14 @@ static time_t ve_utc = 0;
* set ve_utc used for certificate verification
*
* @param[in] utc
* time - ignored unless greater than current value.
* time - ignored unless greater than current value
* and not a leap of 20 years or more.
*/
void
ve_utc_set(time_t utc)
{
if (utc > ve_utc) {
if (utc > ve_utc &&
(ve_utc == 0 || (utc - ve_utc) < VE_UTC_MAX_JUMP)) {
DEBUG_PRINTF(2, ("Set ve_utc=%jd\n", (intmax_t)utc));
ve_utc = utc;
}
@ -346,10 +352,10 @@ ve_trust_init(void)
if (once >= 0)
return (once);
once = 0; /* to be sure */
ve_utc_set(time(NULL));
#ifdef BUILD_UTC
ve_utc_set(BUILD_UTC); /* just in case */
ve_utc_set(BUILD_UTC); /* ensure sanity */
#endif
ve_utc_set(time(NULL));
ve_error_set(NULL); /* make sure it is empty */
#ifdef VE_PCR_SUPPORT
ve_pcr_init();
@ -903,7 +909,7 @@ ve_check_hash(br_hash_compat_context *ctx, const br_hash_class *md,
md->out(&ctx->vtable, hbuf);
#ifdef VE_PCR_SUPPORT
ve_pcr_update(hbuf, hlen);
ve_pcr_update(path, hbuf, hlen);
#endif
hex = hexdigest(hexbuf, sizeof(hexbuf), hbuf, hlen);
if (!hex)

11
stand/common/install.c
View File

@ -210,6 +210,13 @@ install(char *pkgname)
if (currdev != NULL && strcmp(currdev, "pxe0:") == 0) {
devname = "pxe0";
proto = NULL;
#ifdef HOSTPROG
} else if (currdev != NULL && strcmp(currdev, "host0:") == 0) {
extern struct fs_ops host_fsops;
devname = "host0";
proto = &host_fsops;
#endif
} else {
devname = "disk1";
proto = &dosfs_fsops;
@ -237,6 +244,10 @@ install(char *pkgname)
setenv("serverip", inet_ntoa(servip), 1);
if (proto == &tftp_fsops) {
tftpip.s_addr = servip.s_addr;
}
*pkgname = '/';
} else
pkgname = s;

19
stand/libsa/pkgfs.c
View File

@ -46,6 +46,7 @@ static int pkg_read(struct open_file *, void *, size_t, size_t *);
static off_t pkg_seek(struct open_file *, off_t, int);
static int pkg_stat(struct open_file *, struct stat *);
static int pkg_readdir(struct open_file *, struct dirent *);
static off_t pkg_atol(const char *, unsigned);
struct fs_ops pkgfs_fsops = {
"pkg",
@ -59,7 +60,7 @@ struct fs_ops pkgfs_fsops = {
};
#define PKG_BUFSIZE 512
#define PKG_MAXCACHESZ 4096
#define PKG_MAXCACHESZ 16384
#define PKG_FILEEXT ".tgz"
@ -334,6 +335,7 @@ pkg_seek(struct open_file *f, off_t ofs, int whence)
char buf[512];
struct tarfile *tf;
off_t delta;
off_t nofs;
size_t sz, res;
int error;
@ -359,6 +361,14 @@ pkg_seek(struct open_file *f, off_t ofs, int whence)
}
if (delta < 0) {
/* seeking backwards - ok if within cache */
if (tf->tf_cachesz > 0 && tf->tf_fp <= tf->tf_cachesz) {
nofs = tf->tf_fp + delta;
if (nofs >= 0) {
tf->tf_fp = nofs;
return (tf->tf_fp);
}
}
DBG(("%s: negative file seek (%jd)\n", __func__,
(intmax_t)delta));
errno = ESPIPE;
@ -388,8 +398,15 @@ pkg_stat(struct open_file *f, struct stat *sb)
return (EBADF);
memset(sb, 0, sizeof(*sb));
sb->st_mode = get_mode(tf);
if ((sb->st_mode & S_IFMT) == 0) {
/* tar file bug - assume regular file */
sb->st_mode |= S_IFREG;
}
sb->st_size = tf->tf_size;
sb->st_blocks = (tf->tf_size + 511) / 512;
sb->st_mtime = pkg_atol(tf->tf_hdr.ut_mtime, 12);
sb->st_dev = (off_t)tf->tf_pkg;
sb->st_ino = tf->tf_ofs; /* unique per tf_pkg */
return (0);
}

17
stand/userboot/test/test.c
View File

@ -224,15 +224,20 @@ test_seek(void *arg, void *h, uint64_t offset, int whence)
}
int
test_stat(void *arg, void *h, int *mode_return, int *uid_return, int *gid_return,
uint64_t *size_return)
test_stat(void *arg, void *h, struct stat *stp)
{
struct test_file *tf = h;
*mode_return = tf->tf_stat.st_mode;
*uid_return = tf->tf_stat.st_uid;
*gid_return = tf->tf_stat.st_gid;
*size_return = tf->tf_stat.st_size;
if (!stp)
return (-1);
memset(stp, 0, sizeof(struct stat));
stp->st_mode = tf->tf_stat.st_mode;
stp->st_uid = tf->tf_stat.st_uid;
stp->st_gid = tf->tf_stat.st_gid;
stp->st_size = tf->tf_stat.st_size;
stp->st_ino = tf->tf_stat.st_ino;
stp->st_dev = tf->tf_stat.st_dev;
stp->st_mtime = tf->tf_stat.st_mtime;
return (0);
}

3
stand/userboot/userboot.h
View File

@ -119,8 +119,7 @@ struct loader_callbacks {
/*
* Return some stat(2) related information about the file
*/
int (*stat)(void *arg, void *h, int *mode_return,
int *uid_return, int *gid_return, uint64_t *size_return);
int (*stat)(void *arg, void *h, struct stat *stp);
/*
* Disk image i/o

5
stand/userboot/userboot/conf.c
View File

@ -73,6 +73,11 @@ struct fs_ops *file_system[] = {
NULL
};
/* to keep libsa happy */
struct netif_driver *netif_drivers[] = {
NULL
};
/* Exported for i386 only */
/*
* Sort formats so that those that can detect based on arguments

12
stand/userboot/userboot/host.c
View File

@ -84,16 +84,8 @@ host_seek(struct open_file *f, off_t offset, int where)
static int
host_stat(struct open_file *f, struct stat *sb)
{
int mode;
int uid;
int gid;
uint64_t size;
CALLBACK(stat, f->f_fsdata, &mode, &uid, &gid, &size);
sb->st_mode = mode;
sb->st_uid = uid;
sb->st_gid = gid;
sb->st_size = size;
CALLBACK(stat, f->f_fsdata, sb);
return (0);
}

15
usr.sbin/bhyveload/bhyveload.c
View File

@ -278,14 +278,19 @@ cb_seek(void *arg, void *h, uint64_t offset, int whence)
}
static int
cb_stat(void *arg, void *h, int *mode, int *uid, int *gid, uint64_t *size)
cb_stat(void *arg, void *h, struct stat *sbp)
{
struct cb_file *cf = h;
*mode = cf->cf_stat.st_mode;
*uid = cf->cf_stat.st_uid;
*gid = cf->cf_stat.st_gid;
*size = cf->cf_stat.st_size;
memset(sbp, 0, sizeof(struct stat));
sbp->st_mode = cf->cf_stat.st_mode;
sbp->st_uid = cf->cf_stat.st_uid;
sbp->st_gid = cf->cf_stat.st_gid;
sbp->st_size = cf->cf_stat.st_size;
sbp->st_mtime = cf->cf_stat.st_mtime;
sbp->st_dev = cf->cf_stat.st_dev;
sbp->st_ino = cf->cf_stat.st_ino;
return (0);
}