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/*-
* Copyright (c) 2019 Stormshield.
* Copyright (c) 2019 Semihalf.
*
* 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/stat.h>
#include "libsecureboot-priv.h"
#include <verify_file.h>
/*
* Values to pass to kernel by envs.
*/
static char manifest_path[MAXPATHLEN];
static char manifest_prefix[MAXPATHLEN];
static char manifest_hash[2 * br_sha256_SIZE + 2];
static int manifest_present = 0;
/*
* Verify and pass manifest path and digest to kernel through envs.
* The paths in manifest can be either absolute,
* or "prefix", if exists will be added to the ones that are not.
*/
int
pass_manifest(const char *path, const char *prefix)
{
char *content;
struct stat st;
unsigned char digest[br_sha256_SIZE];
const br_hash_class *md;
br_hash_compat_context ctx;
int rc;
content = NULL;
md = &br_sha256_vtable;
if (strnlen(path, MAXPATHLEN) == MAXPATHLEN ||
strnlen(prefix, MAXPATHLEN) == MAXPATHLEN)
return (EINVAL);
rc = stat(path, &st);
if (rc != 0)
goto out;
if (!S_ISREG(st.st_mode)) {
rc = EINVAL;
goto out;
}
rc = is_verified(&st);
if (rc != VE_NOT_CHECKED && rc != VE_VERIFIED) {
rc = EPERM;
goto out;
}
if (rc == VE_VERIFIED)
content = read_file(path, NULL);
else
content = (char *)verify_signed(path, VEF_VERBOSE);
if (content == NULL) {
add_verify_status(&st, VE_FINGERPRINT_WRONG);
rc = EIO;
goto out;
}
add_verify_status(&st, VE_VERIFIED);
md->init(&ctx.vtable);
md->update(&ctx.vtable, content, st.st_size);
md->out(&ctx.vtable, digest);
if (prefix == NULL)
manifest_prefix[0] = '\0';
else
strcpy(manifest_prefix, prefix);
strcpy(manifest_path, path);
hexdigest(manifest_hash, 2 * br_sha256_SIZE + 2,
digest, br_sha256_SIZE);
manifest_hash[2*br_sha256_SIZE] = '\0';
manifest_present = 1;
rc = 0;
out:
if (content != NULL)
free(content);
return (rc);
}
/*
* Set appropriate envs to inform kernel about manifest location and digest.
* This should be called right before boot so that envs can't be replaced.
*/
int
pass_manifest_export_envs()
{
int rc;
/* If we have nothing to pass make sure that envs are empty. */
if (!manifest_present) {
unsetenv("veriexec.manifest_path");
unsetenv("veriexec.manifest_hash");
unsetenv("veriexec.manifest_prefix");
return (0);
}
rc = setenv("veriexec.manifest_path", manifest_path, 1);
if (rc != 0)
return (rc);
rc = setenv("veriexec.manifest_hash", manifest_hash, 1);
if (rc != 0) {
unsetenv("veriexec.manifest_path");
return (rc);
}
if (manifest_prefix[0] != '\0')
rc = setenv("veriexec.manifest_prefix", manifest_prefix, 1);
return (rc);
}
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