Upgrade fsverity-utils to 2151209ce1dae61c4ee7480e2c39ada1d912fcb2
am: d318ab55d3
Change-Id: I07e68a88f63dd6b2dc3cfdfb01332ee48ac9d670
diff --git a/METADATA b/METADATA
index 2f19f50..c92888e 100644
--- a/METADATA
+++ b/METADATA
@@ -5,11 +5,11 @@
type: GIT
value: "https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/fsverity-utils.git"
}
- version: "23a20ab7e8371cc29015d7d5787daa73f2ddd374"
+ version: "2151209ce1dae61c4ee7480e2c39ada1d912fcb2"
license_type: RESTRICTED
last_upgrade_date {
year: 2019
- month: 2
- day: 11
+ month: 7
+ day: 24
}
}
diff --git a/README.md b/README.md
index be2a251..8a72088 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,9 @@
# Introduction
-This is `fsverity`, a userspace utility for fs-verity. fs-verity is
-a Linux kernel feature that does transparent on-demand
+This is `fsverity`, a userspace utility for fs-verity. fs-verity is a
+Linux kernel feature that does transparent on-demand
integrity/authenticity verification of the contents of read-only
-files, using a Merkle tree (hash tree) hidden after the end of the
+files, using a hidden Merkle tree (hash tree) associated with the
file. The mechanism is similar to dm-verity, but implemented at the
file level rather than at the block device level. The `fsverity`
utility allows you to set up fs-verity protected files.
@@ -35,7 +35,7 @@
## Basic use
```bash
- mkfs.f2fs -O verity /dev/vdc
+ mkfs.ext4 -O verity /dev/vdc
mount /dev/vdc /vdc
cd /vdc
@@ -43,18 +43,16 @@
head -c 1000000 /dev/urandom > file
md5sum file
- # Append the Merkle tree and other metadata to the file:
- fsverity setup file
-
- # Enable fs-verity on the file
+ # Enable verity on the file
fsverity enable file
- # Should show the same hash that 'fsverity setup' printed.
- # This hash can be logged, or compared to a trusted value.
+ # Show the verity file measurement
fsverity measure file
- # Contents are now transparently verified and should match the
- # original file contents, i.e. the metadata is hidden.
+ # File should still be readable as usual. However, all data read
+ # is now transparently checked against a hidden Merkle tree, whose
+ # root hash is incorporated into the verity file measurement.
+ # Reads of any corrupted parts of the data will fail.
md5sum file
```
@@ -67,7 +65,7 @@
With `CONFIG_FS_VERITY_BUILTIN_SIGNATURES=y`, the filesystem supports
automatically verifying a signed file measurement that has been
-included in the fs-verity metadata. The signature is verified against
+included in the verity metadata. The signature is verified against
the set of X.509 certificates that have been loaded into the
".fs-verity" kernel keyring. Here's an example:
@@ -85,24 +83,25 @@
# (requires keyctl v1.5.11 or later):
keyctl restrict_keyring %keyring:.fs-verity
- # Optionally, require that all fs-verity files be signed:
+ # Optionally, require that all verity files be signed:
sysctl fs.verity.require_signatures=1
# Now set up fs-verity on a test file:
md5sum file
- fsverity setup file --signing-key=key.pem --signing-cert=cert.pem
- fsverity enable file
+ fsverity sign file file.sig --key=key.pem --cert=cert.pem
+ fsverity enable file --signature=file.sig
+ rm -f file.sig
md5sum file
```
-By default, it's not required that fs-verity files have a signature.
+By default, it's not required that verity files have a signature.
This can be changed with `sysctl fs.verity.require_signatures=1`.
-When set, it's guaranteed that the contents of every fs-verity file
-has been signed by one of the certificates in the keyring.
+When set, it's guaranteed that the contents of every verity file has
+been signed by one of the certificates in the keyring.
Note: applications generally still need to check whether the file
-they're accessing really is a fs-verity file, since an attacker could
-replace a fs-verity file with a regular one.
+they're accessing really is a verity file, since an attacker could
+replace a verity file with a regular one.
## With IMA
diff --git a/cmd_enable.c b/cmd_enable.c
index ed092f0..1646299 100644
--- a/cmd_enable.c
+++ b/cmd_enable.c
@@ -8,30 +8,165 @@
*/
#include <fcntl.h>
+#include <getopt.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
#include <sys/ioctl.h>
#include "commands.h"
#include "fsverity_uapi.h"
+#include "hash_algs.h"
+static bool parse_hash_alg_option(const char *arg, u32 *alg_ptr)
+{
+ char *end;
+ unsigned long n = strtoul(arg, &end, 10);
+ const struct fsverity_hash_alg *alg;
+
+ if (*alg_ptr != 0) {
+ error_msg("--hash-alg can only be specified once");
+ return false;
+ }
+
+ /* Specified by number? */
+ if (n > 0 && n < INT32_MAX && *end == '\0') {
+ *alg_ptr = n;
+ return true;
+ }
+
+ /* Specified by name? */
+ alg = find_hash_alg_by_name(arg);
+ if (alg != NULL) {
+ *alg_ptr = alg - fsverity_hash_algs;
+ return true;
+ }
+ return false;
+}
+
+static bool read_signature(const char *filename, u8 **sig_ret,
+ u32 *sig_size_ret)
+{
+ struct filedes file = { .fd = -1 };
+ u64 file_size;
+ u8 *sig = NULL;
+ bool ok = false;
+
+ if (!open_file(&file, filename, O_RDONLY, 0))
+ goto out;
+ if (!get_file_size(&file, &file_size))
+ goto out;
+ if (file_size <= 0) {
+ error_msg("signature file '%s' is empty", filename);
+ goto out;
+ }
+ if (file_size > 1000000) {
+ error_msg("signature file '%s' is too large", filename);
+ goto out;
+ }
+ sig = xmalloc(file_size);
+ if (!full_read(&file, sig, file_size))
+ goto out;
+ *sig_ret = sig;
+ *sig_size_ret = file_size;
+ sig = NULL;
+ ok = true;
+out:
+ filedes_close(&file);
+ free(sig);
+ return ok;
+}
+
+enum {
+ OPT_HASH_ALG,
+ OPT_BLOCK_SIZE,
+ OPT_SALT,
+ OPT_SIGNATURE,
+};
+
+static const struct option longopts[] = {
+ {"hash-alg", required_argument, NULL, OPT_HASH_ALG},
+ {"block-size", required_argument, NULL, OPT_BLOCK_SIZE},
+ {"salt", required_argument, NULL, OPT_SALT},
+ {"signature", required_argument, NULL, OPT_SIGNATURE},
+ {NULL, 0, NULL, 0}
+};
+
+/* Enable fs-verity on a file. */
int fsverity_cmd_enable(const struct fsverity_command *cmd,
int argc, char *argv[])
{
+ struct fsverity_enable_arg arg = { .version = 1 };
+ u8 *salt = NULL;
+ u8 *sig = NULL;
struct filedes file;
+ int status;
+ int c;
- if (argc != 2) {
- usage(cmd, stderr);
- return 2;
+ while ((c = getopt_long(argc, argv, "", longopts, NULL)) != -1) {
+ switch (c) {
+ case OPT_HASH_ALG:
+ if (!parse_hash_alg_option(optarg, &arg.hash_algorithm))
+ goto out_usage;
+ break;
+ case OPT_BLOCK_SIZE:
+ if (!parse_block_size_option(optarg, &arg.block_size))
+ goto out_usage;
+ break;
+ case OPT_SALT:
+ if (!parse_salt_option(optarg, &salt, &arg.salt_size))
+ goto out_usage;
+ arg.salt_ptr = (uintptr_t)salt;
+ break;
+ case OPT_SIGNATURE:
+ if (sig != NULL) {
+ error_msg("--signature can only be specified once");
+ goto out_usage;
+ }
+ if (!read_signature(optarg, &sig, &arg.sig_size))
+ goto out_err;
+ arg.sig_ptr = (uintptr_t)sig;
+ break;
+ default:
+ goto out_usage;
+ }
}
- if (!open_file(&file, argv[1], O_RDONLY, 0))
- return 1;
- if (ioctl(file.fd, FS_IOC_ENABLE_VERITY, NULL) != 0) {
+ argv += optind;
+ argc -= optind;
+
+ if (argc != 1)
+ goto out_usage;
+
+ if (arg.hash_algorithm == 0)
+ arg.hash_algorithm = FS_VERITY_HASH_ALG_DEFAULT;
+
+ if (arg.block_size == 0)
+ arg.block_size = get_default_block_size();
+
+ if (!open_file(&file, argv[0], O_RDONLY, 0))
+ goto out_err;
+ if (ioctl(file.fd, FS_IOC_ENABLE_VERITY, &arg) != 0) {
error_msg_errno("FS_IOC_ENABLE_VERITY failed on '%s'",
file.name);
filedes_close(&file);
- return 1;
+ goto out_err;
}
if (!filedes_close(&file))
- return 1;
- return 0;
+ goto out_err;
+
+ status = 0;
+out:
+ free(salt);
+ free(sig);
+ return status;
+
+out_err:
+ status = 1;
+ goto out;
+
+out_usage:
+ usage(cmd, stderr);
+ status = 2;
+ goto out;
}
diff --git a/cmd_measure.c b/cmd_measure.c
index a5480a6..574e3ca 100644
--- a/cmd_measure.c
+++ b/cmd_measure.c
@@ -15,6 +15,7 @@
#include "fsverity_uapi.h"
#include "hash_algs.h"
+/* Display the measurement of the given verity file(s). */
int fsverity_cmd_measure(const struct fsverity_command *cmd,
int argc, char *argv[])
{
diff --git a/cmd_setup.c b/cmd_setup.c
deleted file mode 100644
index c598a71..0000000
--- a/cmd_setup.c
+++ /dev/null
@@ -1,565 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * The 'fsverity setup' command
- *
- * Copyright (C) 2018 Google LLC
- *
- * Written by Eric Biggers.
- */
-
-#include <fcntl.h>
-#include <getopt.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include "commands.h"
-#include "fsverity_uapi.h"
-#include "fsveritysetup.h"
-#include "hash_algs.h"
-
-enum {
- OPT_HASH,
- OPT_SALT,
- OPT_BLOCKSIZE,
- OPT_SIGNING_KEY,
- OPT_SIGNING_CERT,
- OPT_SIGNATURE,
- OPT_ELIDE,
- OPT_PATCH,
-};
-
-static const struct option longopts[] = {
- {"hash", required_argument, NULL, OPT_HASH},
- {"salt", required_argument, NULL, OPT_SALT},
- {"blocksize", required_argument, NULL, OPT_BLOCKSIZE},
- {"signing-key", required_argument, NULL, OPT_SIGNING_KEY},
- {"signing-cert", required_argument, NULL, OPT_SIGNING_CERT},
- {"signature", required_argument, NULL, OPT_SIGNATURE},
- {"elide", required_argument, NULL, OPT_ELIDE},
- {"patch", required_argument, NULL, OPT_PATCH},
- {NULL, 0, NULL, 0}
-};
-
-/* Parse the --blocksize=BLOCKSIZE option */
-static bool parse_blocksize_option(const char *opt, int *blocksize_ret)
-{
- char *end;
- unsigned long n = strtoul(opt, &end, 10);
-
- if (n <= 0 || n >= INT32_MAX || *end || !is_power_of_2(n)) {
- error_msg("Invalid block size: %s. Must be power of 2", opt);
- return false;
- }
- *blocksize_ret = n;
- return true;
-}
-
-#define FS_VERITY_MAX_LEVELS 64
-
-/*
- * Calculate the depth of the Merkle tree, then create a map from level to the
- * block offset at which that level's hash blocks start. Level 'depth - 1' is
- * the root and is stored first in the file, in the first block following the
- * original data. Level 0 is the "leaf" level: it's directly "above" the data
- * blocks and is stored last in the file.
- */
-static void compute_tree_layout(u64 data_size, u64 tree_offset, int blockbits,
- unsigned int hashes_per_block,
- u64 hash_lvl_region_idx[FS_VERITY_MAX_LEVELS],
- int *depth_ret, u64 *tree_end_ret)
-{
- u64 blocks = data_size >> blockbits;
- u64 offset = tree_offset >> blockbits;
- int depth = 0;
- int i;
-
- ASSERT(data_size > 0);
- ASSERT(data_size % (1 << blockbits) == 0);
- ASSERT(tree_offset % (1 << blockbits) == 0);
- ASSERT(hashes_per_block >= 2);
-
- while (blocks > 1) {
- ASSERT(depth < FS_VERITY_MAX_LEVELS);
- blocks = DIV_ROUND_UP(blocks, hashes_per_block);
- hash_lvl_region_idx[depth++] = blocks;
- }
- for (i = depth - 1; i >= 0; i--) {
- u64 next_count = hash_lvl_region_idx[i];
-
- hash_lvl_region_idx[i] = offset;
- offset += next_count;
- }
- *depth_ret = depth;
- *tree_end_ret = offset << blockbits;
-}
-
-/*
- * Build a Merkle tree (hash tree) over the data of a file.
- *
- * @params: Block size, hashes per block, and salt
- * @hash: Handle for the hash algorithm
- * @data_file: input data file
- * @data_size: size of data file in bytes; must be aligned to ->blocksize
- * @tree_file: output tree file
- * @tree_offset: byte offset in tree file at which to write the tree;
- * must be aligned to ->blocksize
- * @tree_end_ret: On success, the byte offset in the tree file of the end of the
- * tree is written here
- * @root_hash_ret: On success, the Merkle tree root hash is written here
- *
- * Return: exit status code (0 on success, nonzero on failure)
- */
-static int build_merkle_tree(const struct fsveritysetup_params *params,
- struct hash_ctx *hash,
- struct filedes *data_file, u64 data_size,
- struct filedes *tree_file, u64 tree_offset,
- u64 *tree_end_ret, u8 *root_hash_ret)
-{
- const unsigned int digest_size = hash->alg->digest_size;
- int depth;
- u64 hash_lvl_region_idx[FS_VERITY_MAX_LEVELS];
- u8 *data_to_hash = NULL;
- u8 *pending_hashes = NULL;
- unsigned int pending_hash_bytes;
- u64 nr_hashes_at_this_lvl;
- int lvl;
- int status;
-
- compute_tree_layout(data_size, tree_offset, params->blockbits,
- params->hashes_per_block, hash_lvl_region_idx,
- &depth, tree_end_ret);
-
- /* Allocate block buffers */
- data_to_hash = xmalloc(params->blocksize);
- pending_hashes = xmalloc(params->blocksize);
- pending_hash_bytes = 0;
- nr_hashes_at_this_lvl = data_size >> params->blockbits;
-
- /*
- * Generate each level of the Merkle tree, starting at the leaf level
- * ('lvl == 0') and ascending to the root node ('lvl == depth - 1').
- * Then at the end ('lvl == depth'), calculate the root node's hash.
- */
- for (lvl = 0; lvl <= depth; lvl++) {
- u64 i;
-
- for (i = 0; i < nr_hashes_at_this_lvl; i++) {
- struct filedes *file;
- u64 blk_idx;
-
- hash_init(hash);
- hash_update(hash, params->salt, params->saltlen);
-
- if (lvl == 0) {
- /* Leaf: hashing a data block */
- file = data_file;
- blk_idx = i;
- } else {
- /* Non-leaf: hashing a hash block */
- file = tree_file;
- blk_idx = hash_lvl_region_idx[lvl - 1] + i;
- }
- if (!full_pread(file, data_to_hash, params->blocksize,
- blk_idx << params->blockbits))
- goto out_err;
- hash_update(hash, data_to_hash, params->blocksize);
-
- hash_final(hash, &pending_hashes[pending_hash_bytes]);
- pending_hash_bytes += digest_size;
-
- if (lvl == depth) {
- /* Root hash */
- ASSERT(nr_hashes_at_this_lvl == 1);
- ASSERT(pending_hash_bytes == digest_size);
- memcpy(root_hash_ret, pending_hashes,
- digest_size);
- status = 0;
- goto out;
- }
-
- if (pending_hash_bytes + digest_size > params->blocksize
- || i + 1 == nr_hashes_at_this_lvl) {
- /* Flush the pending hash block */
- memset(&pending_hashes[pending_hash_bytes], 0,
- params->blocksize - pending_hash_bytes);
- blk_idx = hash_lvl_region_idx[lvl] +
- (i / params->hashes_per_block);
- if (!full_pwrite(tree_file,
- pending_hashes,
- params->blocksize,
- blk_idx << params->blockbits))
- goto out_err;
- pending_hash_bytes = 0;
- }
- }
-
- nr_hashes_at_this_lvl = DIV_ROUND_UP(nr_hashes_at_this_lvl,
- params->hashes_per_block);
- }
- ASSERT(0); /* unreachable; should exit via "Root hash" case above */
-out_err:
- status = 1;
-out:
- free(data_to_hash);
- free(pending_hashes);
- return status;
-}
-
-/*
- * Append to the buffer @*buf_p an extension (variable-length metadata) item of
- * type @type, containing the data @ext of length @extlen bytes.
- */
-void fsverity_append_extension(void **buf_p, int type,
- const void *ext, size_t extlen)
-{
- void *buf = *buf_p;
- struct fsverity_extension *hdr = buf;
-
- hdr->type = cpu_to_le16(type);
- hdr->length = cpu_to_le32(sizeof(*hdr) + extlen);
- hdr->reserved = 0;
- buf += sizeof(*hdr);
- memcpy(buf, ext, extlen);
- buf += extlen;
- memset(buf, 0, -extlen & 7);
- buf += -extlen & 7;
- ASSERT(buf - *buf_p == FSVERITY_EXTLEN(extlen));
- *buf_p = buf;
-}
-
-/*
- * Append the authenticated portion of the fs-verity descriptor to 'out', in the
- * process updating 'hash' with the data written.
- */
-static int append_fsverity_descriptor(const struct fsveritysetup_params *params,
- u64 filesize, const u8 *root_hash,
- struct filedes *out,
- struct hash_ctx *hash)
-{
- size_t desc_auth_len;
- void *buf;
- struct fsverity_descriptor *desc;
- u16 auth_ext_count;
- int status;
-
- desc_auth_len = sizeof(*desc);
- desc_auth_len += FSVERITY_EXTLEN(params->hash_alg->digest_size);
- if (params->saltlen)
- desc_auth_len += FSVERITY_EXTLEN(params->saltlen);
- desc_auth_len += total_elide_patch_ext_length(params);
- desc = buf = xzalloc(desc_auth_len);
-
- memcpy(desc->magic, FS_VERITY_MAGIC, sizeof(desc->magic));
- desc->major_version = 1;
- desc->minor_version = 0;
- desc->log_data_blocksize = params->blockbits;
- desc->log_tree_blocksize = params->blockbits;
- desc->data_algorithm = cpu_to_le16(params->hash_alg -
- fsverity_hash_algs);
- desc->tree_algorithm = desc->data_algorithm;
- desc->orig_file_size = cpu_to_le64(filesize);
-
- auth_ext_count = 1; /* root hash */
- if (params->saltlen)
- auth_ext_count++;
- auth_ext_count += params->num_elisions_and_patches;
- desc->auth_ext_count = cpu_to_le16(auth_ext_count);
-
- buf += sizeof(*desc);
- fsverity_append_extension(&buf, FS_VERITY_EXT_ROOT_HASH,
- root_hash, params->hash_alg->digest_size);
- if (params->saltlen)
- fsverity_append_extension(&buf, FS_VERITY_EXT_SALT,
- params->salt, params->saltlen);
- append_elide_patch_exts(&buf, params);
- ASSERT(buf - (void *)desc == desc_auth_len);
-
- hash_update(hash, desc, desc_auth_len);
- if (!full_write(out, desc, desc_auth_len))
- goto out_err;
- status = 0;
-out:
- free(desc);
- return status;
-
-out_err:
- status = 1;
- goto out;
-}
-
-/*
- * Append any needed unauthenticated extension items: currently, just possibly a
- * PKCS7_SIGNATURE item containing the signed file measurement.
- */
-static int
-append_unauthenticated_extensions(struct filedes *out,
- const struct fsveritysetup_params *params,
- const u8 *measurement)
-{
- u16 unauth_ext_count = 0;
- struct {
- __le16 unauth_ext_count;
- __le16 pad[3];
- } hdr;
- bool have_sig = params->signing_key_file || params->signature_file;
-
- if (have_sig)
- unauth_ext_count++;
-
- ASSERT(sizeof(hdr) % 8 == 0);
- memset(&hdr, 0, sizeof(hdr));
- hdr.unauth_ext_count = cpu_to_le16(unauth_ext_count);
-
- if (!full_write(out, &hdr, sizeof(hdr)))
- return 1;
-
- if (have_sig)
- return append_signed_measurement(out, params, measurement);
-
- return 0;
-}
-
-static int append_footer(struct filedes *out, u64 desc_offset)
-{
- struct fsverity_footer ftr;
- u32 offset = (out->pos + sizeof(ftr)) - desc_offset;
-
- ftr.desc_reverse_offset = cpu_to_le32(offset);
- memcpy(ftr.magic, FS_VERITY_MAGIC, sizeof(ftr.magic));
-
- if (!full_write(out, &ftr, sizeof(ftr)))
- return 1;
- return 0;
-}
-
-static int fsveritysetup(const char *infile, const char *outfile,
- const struct fsveritysetup_params *params)
-{
- struct filedes _in = { .fd = -1 };
- struct filedes _out = { .fd = -1 };
- struct filedes _tmp = { .fd = -1 };
- struct hash_ctx *hash = NULL;
- struct filedes *in = &_in, *out = &_out, *src;
- u64 filesize;
- u64 aligned_filesize;
- u64 src_filesize;
- u64 tree_end_offset;
- u8 root_hash[FS_VERITY_MAX_DIGEST_SIZE];
- u8 measurement[FS_VERITY_MAX_DIGEST_SIZE];
- char hash_hex[FS_VERITY_MAX_DIGEST_SIZE * 2 + 1];
- int status;
-
- if (!open_file(in, infile, (infile == outfile ? O_RDWR : O_RDONLY), 0))
- goto out_err;
-
- if (!get_file_size(in, &filesize))
- goto out_err;
-
- if (filesize <= 0) {
- error_msg("input file is empty: '%s'", infile);
- goto out_err;
- }
-
- if (infile == outfile) {
- /*
- * Invoked with one file argument: we're appending verity
- * metadata to an existing file.
- */
- out = in;
- if (!filedes_seek(out, filesize, SEEK_SET))
- goto out_err;
- } else {
- /*
- * Invoked with two file arguments: we're copying the first file
- * to the second file, then appending verity metadata to it.
- */
- if (!open_file(out, outfile, O_RDWR|O_CREAT|O_TRUNC, 0644))
- goto out_err;
- if (!copy_file_data(in, out, filesize))
- goto out_err;
- }
-
- /* Zero-pad the output file to the next block boundary */
- aligned_filesize = ALIGN(filesize, params->blocksize);
- if (!write_zeroes(out, aligned_filesize - filesize))
- goto out_err;
-
- if (params->num_elisions_and_patches) {
- /* Merkle tree is built over temporary elided/patched file */
- src = &_tmp;
- if (!apply_elisions_and_patches(params, in, filesize,
- src, &src_filesize))
- goto out_err;
- } else {
- /* Merkle tree is built over original file */
- src = out;
- src_filesize = aligned_filesize;
- }
-
- hash = hash_create(params->hash_alg);
-
- /* Build the file's Merkle tree and calculate its root hash */
- status = build_merkle_tree(params, hash, src, src_filesize,
- out, aligned_filesize,
- &tree_end_offset, root_hash);
- if (status)
- goto out;
- if (!filedes_seek(out, tree_end_offset, SEEK_SET))
- goto out_err;
-
- /* Append the additional needed metadata */
-
- hash_init(hash);
- status = append_fsverity_descriptor(params, filesize, root_hash,
- out, hash);
- if (status)
- goto out;
- hash_final(hash, measurement);
-
- status = append_unauthenticated_extensions(out, params, measurement);
- if (status)
- goto out;
-
- status = append_footer(out, tree_end_offset);
- if (status)
- goto out;
-
- bin2hex(measurement, params->hash_alg->digest_size, hash_hex);
- printf("File measurement: %s:%s\n", params->hash_alg->name, hash_hex);
- status = 0;
-out:
- hash_free(hash);
- if (status != 0 && out->fd >= 0) {
- /* Error occurred; undo what we wrote */
- if (in == out)
- (void)ftruncate(out->fd, filesize);
- else
- out->autodelete = true;
- }
- filedes_close(&_in);
- filedes_close(&_tmp);
- if (!filedes_close(&_out) && status == 0)
- status = 1;
- return status;
-
-out_err:
- status = 1;
- goto out;
-}
-
-int fsverity_cmd_setup(const struct fsverity_command *cmd,
- int argc, char *argv[])
-{
- struct fsveritysetup_params params = {
- .hash_alg = DEFAULT_HASH_ALG,
- };
- STRING_LIST(elide_opts);
- STRING_LIST(patch_opts);
- int c;
- int status;
-
- while ((c = getopt_long(argc, argv, "", longopts, NULL)) != -1) {
- switch (c) {
- case OPT_HASH:
- params.hash_alg = find_hash_alg_by_name(optarg);
- if (!params.hash_alg)
- goto out_usage;
- break;
- case OPT_SALT:
- if (params.salt) {
- error_msg("--salt can only be specified once");
- goto out_usage;
- }
- params.saltlen = strlen(optarg) / 2;
- params.salt = xmalloc(params.saltlen);
- if (!hex2bin(optarg, params.salt, params.saltlen)) {
- error_msg("salt is not a valid hex string");
- goto out_usage;
- }
- break;
- case OPT_BLOCKSIZE:
- if (!parse_blocksize_option(optarg, ¶ms.blocksize))
- goto out_usage;
- break;
- case OPT_SIGNING_KEY:
- params.signing_key_file = optarg;
- break;
- case OPT_SIGNING_CERT:
- params.signing_cert_file = optarg;
- break;
- case OPT_SIGNATURE:
- params.signature_file = optarg;
- break;
- case OPT_ELIDE:
- string_list_append(&elide_opts, optarg);
- break;
- case OPT_PATCH:
- string_list_append(&patch_opts, optarg);
- break;
- default:
- goto out_usage;
- }
- }
-
- argv += optind;
- argc -= optind;
-
- if (argc != 1 && argc != 2)
- goto out_usage;
-
- ASSERT(params.hash_alg->digest_size <= FS_VERITY_MAX_DIGEST_SIZE);
-
- if (params.blocksize == 0) {
- params.blocksize = sysconf(_SC_PAGESIZE);
- if (params.blocksize <= 0 || !is_power_of_2(params.blocksize)) {
- fprintf(stderr,
- "Warning: invalid _SC_PAGESIZE (%d). Assuming 4K blocks.\n",
- params.blocksize);
- params.blocksize = 4096;
- }
- }
- params.blockbits = ilog2(params.blocksize);
-
- params.hashes_per_block = params.blocksize /
- params.hash_alg->digest_size;
- if (params.hashes_per_block < 2) {
- error_msg("block size of %d bytes is too small for %s hash",
- params.blocksize, params.hash_alg->name);
- goto out_err;
- }
-
- if (params.signing_cert_file && !params.signing_key_file) {
- error_msg("--signing-cert was given, but --signing-key was not.\n"
-" You must provide the certificate's private key file using --signing-key.");
- goto out_err;
- }
-
- if ((params.signing_key_file || params.signature_file) &&
- !params.hash_alg->cryptographic) {
- error_msg("Signing a file using '%s' checksums does not make sense\n"
- " because '%s' is not a cryptographically secure hash algorithm.",
- params.hash_alg->name, params.hash_alg->name);
- goto out_err;
- }
-
- if (!load_elisions_and_patches(&elide_opts, &patch_opts, ¶ms))
- goto out_err;
-
- status = fsveritysetup(argv[0], argv[argc - 1], ¶ms);
-out:
- free(params.salt);
- free_elisions_and_patches(¶ms);
- string_list_destroy(&elide_opts);
- string_list_destroy(&patch_opts);
- return status;
-
-out_err:
- status = 1;
- goto out;
-
-out_usage:
- usage(cmd, stderr);
- status = 2;
- goto out;
-}
diff --git a/cmd_sign.c b/cmd_sign.c
new file mode 100644
index 0000000..dcb37ce
--- /dev/null
+++ b/cmd_sign.c
@@ -0,0 +1,635 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * The 'fsverity sign' command
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <fcntl.h>
+#include <getopt.h>
+#include <limits.h>
+#include <openssl/bio.h>
+#include <openssl/err.h>
+#include <openssl/pem.h>
+#include <openssl/pkcs7.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "commands.h"
+#include "fsverity_uapi.h"
+#include "hash_algs.h"
+
+/*
+ * Merkle tree properties. The file measurement is the hash of this structure
+ * excluding the signature and with the sig_size field set to 0.
+ */
+struct fsverity_descriptor {
+ __u8 version; /* must be 1 */
+ __u8 hash_algorithm; /* Merkle tree hash algorithm */
+ __u8 log_blocksize; /* log2 of size of data and tree blocks */
+ __u8 salt_size; /* size of salt in bytes; 0 if none */
+ __le32 sig_size; /* size of signature in bytes; 0 if none */
+ __le64 data_size; /* size of file the Merkle tree is built over */
+ __u8 root_hash[64]; /* Merkle tree root hash */
+ __u8 salt[32]; /* salt prepended to each hashed block */
+ __u8 __reserved[144]; /* must be 0's */
+ __u8 signature[]; /* optional PKCS#7 signature */
+};
+
+/*
+ * Format in which verity file measurements are signed. This is the same as
+ * 'struct fsverity_digest', except here some magic bytes are prepended to
+ * provide some context about what is being signed in case the same key is used
+ * for non-fsverity purposes, and here the fields have fixed endianness.
+ */
+struct fsverity_signed_digest {
+ char magic[8]; /* must be "FSVerity" */
+ __le16 digest_algorithm;
+ __le16 digest_size;
+ __u8 digest[];
+};
+
+static void __printf(1, 2) __cold
+error_msg_openssl(const char *format, ...)
+{
+ va_list va;
+
+ va_start(va, format);
+ do_error_msg(format, va, 0);
+ va_end(va);
+
+ if (ERR_peek_error() == 0)
+ return;
+
+ fprintf(stderr, "OpenSSL library errors:\n");
+ ERR_print_errors_fp(stderr);
+}
+
+/* Read a PEM PKCS#8 formatted private key */
+static EVP_PKEY *read_private_key(const char *keyfile)
+{
+ BIO *bio;
+ EVP_PKEY *pkey;
+
+ bio = BIO_new_file(keyfile, "r");
+ if (!bio) {
+ error_msg_openssl("can't open '%s' for reading", keyfile);
+ return NULL;
+ }
+
+ pkey = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);
+ if (!pkey) {
+ error_msg_openssl("Failed to parse private key file '%s'.\n"
+ " Note: it must be in PEM PKCS#8 format.",
+ keyfile);
+ }
+ BIO_free(bio);
+ return pkey;
+}
+
+/* Read a PEM X.509 formatted certificate */
+static X509 *read_certificate(const char *certfile)
+{
+ BIO *bio;
+ X509 *cert;
+
+ bio = BIO_new_file(certfile, "r");
+ if (!bio) {
+ error_msg_openssl("can't open '%s' for reading", certfile);
+ return NULL;
+ }
+ cert = PEM_read_bio_X509(bio, NULL, NULL, NULL);
+ if (!cert) {
+ error_msg_openssl("Failed to parse X.509 certificate file '%s'.\n"
+ " Note: it must be in PEM format.",
+ certfile);
+ }
+ BIO_free(bio);
+ return cert;
+}
+
+#ifdef OPENSSL_IS_BORINGSSL
+
+static bool sign_pkcs7(const void *data_to_sign, size_t data_size,
+ EVP_PKEY *pkey, X509 *cert, const EVP_MD *md,
+ u8 **sig_ret, u32 *sig_size_ret)
+{
+ CBB out, outer_seq, wrapped_seq, seq, digest_algos_set, digest_algo,
+ null, content_info, issuer_and_serial, signer_infos,
+ signer_info, sign_algo, signature;
+ EVP_MD_CTX md_ctx;
+ u8 *name_der = NULL, *sig = NULL, *pkcs7_data = NULL;
+ size_t pkcs7_data_len, sig_len;
+ int name_der_len, sig_nid;
+ bool ok = false;
+
+ EVP_MD_CTX_init(&md_ctx);
+ BIGNUM *serial = ASN1_INTEGER_to_BN(X509_get_serialNumber(cert), NULL);
+
+ if (!CBB_init(&out, 1024)) {
+ error_msg("out of memory");
+ goto out;
+ }
+
+ name_der_len = i2d_X509_NAME(X509_get_subject_name(cert), &name_der);
+ if (name_der_len < 0) {
+ error_msg_openssl("i2d_X509_NAME failed");
+ goto out;
+ }
+
+ if (!EVP_DigestSignInit(&md_ctx, NULL, md, NULL, pkey)) {
+ error_msg_openssl("EVP_DigestSignInit failed");
+ goto out;
+ }
+
+ sig_len = EVP_PKEY_size(pkey);
+ sig = xmalloc(sig_len);
+ if (!EVP_DigestSign(&md_ctx, sig, &sig_len, data_to_sign, data_size)) {
+ error_msg_openssl("EVP_DigestSign failed");
+ goto out;
+ }
+
+ sig_nid = EVP_PKEY_id(pkey);
+ /* To mirror OpenSSL behaviour, always use |NID_rsaEncryption| with RSA
+ * rather than the combined hash+pkey NID. */
+ if (sig_nid != NID_rsaEncryption) {
+ OBJ_find_sigid_by_algs(&sig_nid, EVP_MD_type(md),
+ EVP_PKEY_id(pkey));
+ }
+
+ // See https://tools.ietf.org/html/rfc2315#section-7
+ if (!CBB_add_asn1(&out, &outer_seq, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&outer_seq, NID_pkcs7_signed) ||
+ !CBB_add_asn1(&outer_seq, &wrapped_seq, CBS_ASN1_CONTEXT_SPECIFIC |
+ CBS_ASN1_CONSTRUCTED | 0) ||
+ // See https://tools.ietf.org/html/rfc2315#section-9.1
+ !CBB_add_asn1(&wrapped_seq, &seq, CBS_ASN1_SEQUENCE) ||
+ !CBB_add_asn1_uint64(&seq, 1 /* version */) ||
+ !CBB_add_asn1(&seq, &digest_algos_set, CBS_ASN1_SET) ||
+ !CBB_add_asn1(&digest_algos_set, &digest_algo, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&digest_algo, EVP_MD_type(md)) ||
+ !CBB_add_asn1(&digest_algo, &null, CBS_ASN1_NULL) ||
+ !CBB_add_asn1(&seq, &content_info, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&content_info, NID_pkcs7_data) ||
+ !CBB_add_asn1(&seq, &signer_infos, CBS_ASN1_SET) ||
+ !CBB_add_asn1(&signer_infos, &signer_info, CBS_ASN1_SEQUENCE) ||
+ !CBB_add_asn1_uint64(&signer_info, 1 /* version */) ||
+ !CBB_add_asn1(&signer_info, &issuer_and_serial,
+ CBS_ASN1_SEQUENCE) ||
+ !CBB_add_bytes(&issuer_and_serial, name_der, name_der_len) ||
+ !BN_marshal_asn1(&issuer_and_serial, serial) ||
+ !CBB_add_asn1(&signer_info, &digest_algo, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&digest_algo, EVP_MD_type(md)) ||
+ !CBB_add_asn1(&digest_algo, &null, CBS_ASN1_NULL) ||
+ !CBB_add_asn1(&signer_info, &sign_algo, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&sign_algo, sig_nid) ||
+ !CBB_add_asn1(&sign_algo, &null, CBS_ASN1_NULL) ||
+ !CBB_add_asn1(&signer_info, &signature, CBS_ASN1_OCTETSTRING) ||
+ !CBB_add_bytes(&signature, sig, sig_len) ||
+ !CBB_finish(&out, &pkcs7_data, &pkcs7_data_len)) {
+ error_msg_openssl("failed to construct PKCS#7 data");
+ goto out;
+ }
+
+ *sig_ret = xmemdup(pkcs7_data, pkcs7_data_len);
+ *sig_size_ret = pkcs7_data_len;
+ ok = true;
+out:
+ BN_free(serial);
+ EVP_MD_CTX_cleanup(&md_ctx);
+ CBB_cleanup(&out);
+ free(sig);
+ OPENSSL_free(name_der);
+ OPENSSL_free(pkcs7_data);
+ return ok;
+}
+
+#else /* OPENSSL_IS_BORINGSSL */
+
+static BIO *new_mem_buf(const void *buf, size_t size)
+{
+ BIO *bio;
+
+ ASSERT(size <= INT_MAX);
+ /*
+ * Prior to OpenSSL 1.1.0, BIO_new_mem_buf() took a non-const pointer,
+ * despite still marking the resulting bio as read-only. So cast away
+ * the const to avoid a compiler warning with older OpenSSL versions.
+ */
+ bio = BIO_new_mem_buf((void *)buf, size);
+ if (!bio)
+ error_msg_openssl("out of memory");
+ return bio;
+}
+
+static bool sign_pkcs7(const void *data_to_sign, size_t data_size,
+ EVP_PKEY *pkey, X509 *cert, const EVP_MD *md,
+ u8 **sig_ret, u32 *sig_size_ret)
+{
+ /*
+ * PKCS#7 signing flags:
+ *
+ * - PKCS7_BINARY signing binary data, so skip MIME translation
+ *
+ * - PKCS7_DETACHED omit the signed data (include signature only)
+ *
+ * - PKCS7_NOATTR omit extra authenticated attributes, such as
+ * SMIMECapabilities
+ *
+ * - PKCS7_NOCERTS omit the signer's certificate
+ *
+ * - PKCS7_PARTIAL PKCS7_sign() creates a handle only, then
+ * PKCS7_sign_add_signer() can add a signer later.
+ * This is necessary to change the message digest
+ * algorithm from the default of SHA-1. Requires
+ * OpenSSL 1.0.0 or later.
+ */
+ int pkcs7_flags = PKCS7_BINARY | PKCS7_DETACHED | PKCS7_NOATTR |
+ PKCS7_NOCERTS | PKCS7_PARTIAL;
+ u8 *sig;
+ u32 sig_size;
+ BIO *bio = NULL;
+ PKCS7 *p7 = NULL;
+ bool ok = false;
+
+ bio = new_mem_buf(data_to_sign, data_size);
+ if (!bio)
+ goto out;
+
+ p7 = PKCS7_sign(NULL, NULL, NULL, bio, pkcs7_flags);
+ if (!p7) {
+ error_msg_openssl("failed to initialize PKCS#7 signature object");
+ goto out;
+ }
+
+ if (!PKCS7_sign_add_signer(p7, cert, pkey, md, pkcs7_flags)) {
+ error_msg_openssl("failed to add signer to PKCS#7 signature object");
+ goto out;
+ }
+
+ if (PKCS7_final(p7, bio, pkcs7_flags) != 1) {
+ error_msg_openssl("failed to finalize PKCS#7 signature");
+ goto out;
+ }
+
+ BIO_free(bio);
+ bio = BIO_new(BIO_s_mem());
+ if (!bio) {
+ error_msg_openssl("out of memory");
+ goto out;
+ }
+
+ if (i2d_PKCS7_bio(bio, p7) != 1) {
+ error_msg_openssl("failed to DER-encode PKCS#7 signature object");
+ goto out;
+ }
+
+ sig_size = BIO_get_mem_data(bio, &sig);
+ *sig_ret = xmemdup(sig, sig_size);
+ *sig_size_ret = sig_size;
+ ok = true;
+out:
+ PKCS7_free(p7);
+ BIO_free(bio);
+ return ok;
+}
+
+#endif /* !OPENSSL_IS_BORINGSSL */
+
+/*
+ * Sign the specified @data_to_sign of length @data_size bytes using the private
+ * key in @keyfile, the certificate in @certfile, and the hash algorithm
+ * @hash_alg. Returns the DER-formatted PKCS#7 signature in @sig_ret and
+ * @sig_size_ret.
+ */
+static bool sign_data(const void *data_to_sign, size_t data_size,
+ const char *keyfile, const char *certfile,
+ const struct fsverity_hash_alg *hash_alg,
+ u8 **sig_ret, u32 *sig_size_ret)
+{
+ EVP_PKEY *pkey = NULL;
+ X509 *cert = NULL;
+ const EVP_MD *md;
+ bool ok = false;
+
+ pkey = read_private_key(keyfile);
+ if (!pkey)
+ goto out;
+
+ cert = read_certificate(certfile);
+ if (!cert)
+ goto out;
+
+ OpenSSL_add_all_digests();
+ md = EVP_get_digestbyname(hash_alg->name);
+ if (!md) {
+ fprintf(stderr,
+ "Warning: '%s' algorithm not found in OpenSSL library.\n"
+ " Falling back to SHA-256 signature.\n",
+ hash_alg->name);
+ md = EVP_sha256();
+ }
+
+ ok = sign_pkcs7(data_to_sign, data_size, pkey, cert, md,
+ sig_ret, sig_size_ret);
+out:
+ EVP_PKEY_free(pkey);
+ X509_free(cert);
+ return ok;
+}
+
+static bool write_signature(const char *filename, const u8 *sig, u32 sig_size)
+{
+ struct filedes file;
+ bool ok;
+
+ if (!open_file(&file, filename, O_WRONLY|O_CREAT|O_TRUNC, 0644))
+ return false;
+ ok = full_write(&file, sig, sig_size);
+ ok &= filedes_close(&file);
+ return ok;
+}
+
+#define FS_VERITY_MAX_LEVELS 64
+
+struct block_buffer {
+ u32 filled;
+ u8 *data;
+};
+
+/*
+ * Hash a block, writing the result to the next level's pending block buffer.
+ * Returns true if the next level's block became full, else false.
+ */
+static bool hash_one_block(struct hash_ctx *hash, struct block_buffer *cur,
+ u32 block_size, const u8 *salt, u32 salt_size)
+{
+ struct block_buffer *next = cur + 1;
+
+ /* Zero-pad the block if it's shorter than block_size. */
+ memset(&cur->data[cur->filled], 0, block_size - cur->filled);
+
+ hash_init(hash);
+ hash_update(hash, salt, salt_size);
+ hash_update(hash, cur->data, block_size);
+ hash_final(hash, &next->data[next->filled]);
+
+ next->filled += hash->alg->digest_size;
+ cur->filled = 0;
+
+ return next->filled + hash->alg->digest_size > block_size;
+}
+
+/*
+ * Compute the file's Merkle tree root hash using the given hash algorithm,
+ * block size, and salt.
+ */
+static bool compute_root_hash(struct filedes *file, u64 file_size,
+ struct hash_ctx *hash, u32 block_size,
+ const u8 *salt, u32 salt_size, u8 *root_hash)
+{
+ const u32 hashes_per_block = block_size / hash->alg->digest_size;
+ const u32 padded_salt_size = roundup(salt_size, hash->alg->block_size);
+ u8 *padded_salt = xzalloc(padded_salt_size);
+ u64 blocks;
+ int num_levels = 0;
+ int level;
+ struct block_buffer _buffers[1 + FS_VERITY_MAX_LEVELS + 1] = {};
+ struct block_buffer *buffers = &_buffers[1];
+ u64 offset;
+ bool ok = false;
+
+ if (salt_size != 0)
+ memcpy(padded_salt, salt, salt_size);
+
+ /* Compute number of levels */
+ for (blocks = DIV_ROUND_UP(file_size, block_size); blocks > 1;
+ blocks = DIV_ROUND_UP(blocks, hashes_per_block)) {
+ ASSERT(num_levels < FS_VERITY_MAX_LEVELS);
+ num_levels++;
+ }
+
+ /*
+ * Allocate the block buffers. Buffer "-1" is for data blocks.
+ * Buffers 0 <= level < num_levels are for the actual tree levels.
+ * Buffer 'num_levels' is for the root hash.
+ */
+ for (level = -1; level < num_levels; level++)
+ buffers[level].data = xmalloc(block_size);
+ buffers[num_levels].data = root_hash;
+
+ /* Hash each data block, also hashing the tree blocks as they fill up */
+ for (offset = 0; offset < file_size; offset += block_size) {
+ buffers[-1].filled = min(block_size, file_size - offset);
+
+ if (!full_read(file, buffers[-1].data, buffers[-1].filled))
+ goto out;
+
+ level = -1;
+ while (hash_one_block(hash, &buffers[level], block_size,
+ padded_salt, padded_salt_size)) {
+ level++;
+ ASSERT(level < num_levels);
+ }
+ }
+ /* Finish all nonempty pending tree blocks */
+ for (level = 0; level < num_levels; level++) {
+ if (buffers[level].filled != 0)
+ hash_one_block(hash, &buffers[level], block_size,
+ padded_salt, padded_salt_size);
+ }
+
+ /* Root hash was filled by the last call to hash_one_block() */
+ ASSERT(buffers[num_levels].filled == hash->alg->digest_size);
+ ok = true;
+out:
+ for (level = -1; level < num_levels; level++)
+ free(buffers[level].data);
+ free(padded_salt);
+ return ok;
+}
+
+/*
+ * Compute the fs-verity measurement of the given file.
+ *
+ * The fs-verity measurement is the hash of the fsverity_descriptor, which
+ * contains the Merkle tree properties including the root hash.
+ */
+static bool compute_file_measurement(const char *filename,
+ const struct fsverity_hash_alg *hash_alg,
+ u32 block_size, const u8 *salt,
+ u32 salt_size, u8 *measurement)
+{
+ struct filedes file = { .fd = -1 };
+ struct hash_ctx *hash = hash_create(hash_alg);
+ u64 file_size;
+ struct fsverity_descriptor desc;
+ bool ok = false;
+
+ if (!open_file(&file, filename, O_RDONLY, 0))
+ goto out;
+
+ if (!get_file_size(&file, &file_size))
+ goto out;
+
+ memset(&desc, 0, sizeof(desc));
+ desc.version = 1;
+ desc.hash_algorithm = hash_alg - fsverity_hash_algs;
+
+ ASSERT(is_power_of_2(block_size));
+ desc.log_blocksize = ilog2(block_size);
+
+ if (salt_size != 0) {
+ if (salt_size > sizeof(desc.salt)) {
+ error_msg("Salt too long (got %u bytes; max is %zu bytes)",
+ salt_size, sizeof(desc.salt));
+ goto out;
+ }
+ memcpy(desc.salt, salt, salt_size);
+ desc.salt_size = salt_size;
+ }
+
+ desc.data_size = cpu_to_le64(file_size);
+
+ /* Root hash of empty file is all 0's */
+ if (file_size != 0 &&
+ !compute_root_hash(&file, file_size, hash, block_size, salt,
+ salt_size, desc.root_hash))
+ goto out;
+
+ hash_full(hash, &desc, sizeof(desc), measurement);
+ ok = true;
+out:
+ filedes_close(&file);
+ hash_free(hash);
+ return ok;
+}
+
+enum {
+ OPT_HASH_ALG,
+ OPT_BLOCK_SIZE,
+ OPT_SALT,
+ OPT_KEY,
+ OPT_CERT,
+};
+
+static const struct option longopts[] = {
+ {"hash-alg", required_argument, NULL, OPT_HASH_ALG},
+ {"block-size", required_argument, NULL, OPT_BLOCK_SIZE},
+ {"salt", required_argument, NULL, OPT_SALT},
+ {"key", required_argument, NULL, OPT_KEY},
+ {"cert", required_argument, NULL, OPT_CERT},
+ {NULL, 0, NULL, 0}
+};
+
+/* Sign a file for fs-verity by computing its measurement, then signing it. */
+int fsverity_cmd_sign(const struct fsverity_command *cmd,
+ int argc, char *argv[])
+{
+ const struct fsverity_hash_alg *hash_alg = NULL;
+ u32 block_size = 0;
+ u8 *salt = NULL;
+ u32 salt_size = 0;
+ const char *keyfile = NULL;
+ const char *certfile = NULL;
+ struct fsverity_signed_digest *digest = NULL;
+ char digest_hex[FS_VERITY_MAX_DIGEST_SIZE * 2 + 1];
+ u8 *sig = NULL;
+ u32 sig_size;
+ int status;
+ int c;
+
+ while ((c = getopt_long(argc, argv, "", longopts, NULL)) != -1) {
+ switch (c) {
+ case OPT_HASH_ALG:
+ if (hash_alg != NULL) {
+ error_msg("--hash-alg can only be specified once");
+ goto out_usage;
+ }
+ hash_alg = find_hash_alg_by_name(optarg);
+ if (hash_alg == NULL)
+ goto out_usage;
+ break;
+ case OPT_BLOCK_SIZE:
+ if (!parse_block_size_option(optarg, &block_size))
+ goto out_usage;
+ break;
+ case OPT_SALT:
+ if (!parse_salt_option(optarg, &salt, &salt_size))
+ goto out_usage;
+ break;
+ case OPT_KEY:
+ if (keyfile != NULL) {
+ error_msg("--key can only be specified once");
+ goto out_usage;
+ }
+ keyfile = optarg;
+ break;
+ case OPT_CERT:
+ if (certfile != NULL) {
+ error_msg("--cert can only be specified once");
+ goto out_usage;
+ }
+ certfile = optarg;
+ break;
+ default:
+ goto out_usage;
+ }
+ }
+
+ argv += optind;
+ argc -= optind;
+
+ if (argc != 2)
+ goto out_usage;
+
+ if (hash_alg == NULL)
+ hash_alg = &fsverity_hash_algs[FS_VERITY_HASH_ALG_DEFAULT];
+
+ if (block_size == 0)
+ block_size = get_default_block_size();
+
+ if (keyfile == NULL) {
+ error_msg("Missing --key argument");
+ goto out_usage;
+ }
+ if (certfile == NULL)
+ certfile = keyfile;
+
+ digest = xzalloc(sizeof(*digest) + hash_alg->digest_size);
+ memcpy(digest->magic, "FSVerity", 8);
+ digest->digest_algorithm = cpu_to_le16(hash_alg - fsverity_hash_algs);
+ digest->digest_size = cpu_to_le16(hash_alg->digest_size);
+
+ if (!compute_file_measurement(argv[0], hash_alg, block_size,
+ salt, salt_size, digest->digest))
+ goto out_err;
+
+ if (!sign_data(digest, sizeof(*digest) + hash_alg->digest_size,
+ keyfile, certfile, hash_alg, &sig, &sig_size))
+ goto out_err;
+
+ if (!write_signature(argv[1], sig, sig_size))
+ goto out_err;
+
+ bin2hex(digest->digest, hash_alg->digest_size, digest_hex);
+ printf("Signed file '%s' (%s:%s)\n", argv[0], hash_alg->name,
+ digest_hex);
+ status = 0;
+out:
+ free(salt);
+ free(digest);
+ free(sig);
+ return status;
+
+out_err:
+ status = 1;
+ goto out;
+
+out_usage:
+ usage(cmd, stderr);
+ status = 2;
+ goto out;
+}
diff --git a/commands.h b/commands.h
index cc87368..98f9745 100644
--- a/commands.h
+++ b/commands.h
@@ -12,9 +12,13 @@
int fsverity_cmd_enable(const struct fsverity_command *cmd,
int argc, char *argv[]);
-int fsverity_cmd_setup(const struct fsverity_command *cmd,
- int argc, char *argv[]);
int fsverity_cmd_measure(const struct fsverity_command *cmd,
int argc, char *argv[]);
+int fsverity_cmd_sign(const struct fsverity_command *cmd,
+ int argc, char *argv[]);
+
+bool parse_block_size_option(const char *arg, u32 *size_ptr);
+u32 get_default_block_size(void);
+bool parse_salt_option(const char *arg, u8 **salt_ptr, u32 *salt_size_ptr);
#endif /* COMMANDS_H */
diff --git a/crc32c_table.h b/crc32c_table.h
deleted file mode 100644
index 822c0a6..0000000
--- a/crc32c_table.h
+++ /dev/null
@@ -1,74 +0,0 @@
-/*
- * crc32c_table.h - data table to accelerate CRC-32C computation
- *
- * This file was automatically generated by scripts/gen_crc32c_table.c
- */
-
-#include <stdint.h>
-
-static const uint32_t crc32c_table[] = {
- 0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4,
- 0xc79a971f, 0x35f1141c, 0x26a1e7e8, 0xd4ca64eb,
- 0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b,
- 0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24,
- 0x105ec76f, 0xe235446c, 0xf165b798, 0x030e349b,
- 0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384,
- 0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54,
- 0x5d1d08bf, 0xaf768bbc, 0xbc267848, 0x4e4dfb4b,
- 0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a,
- 0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35,
- 0xaa64d611, 0x580f5512, 0x4b5fa6e6, 0xb93425e5,
- 0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa,
- 0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45,
- 0xf779deae, 0x05125dad, 0x1642ae59, 0xe4292d5a,
- 0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a,
- 0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595,
- 0x417b1dbc, 0xb3109ebf, 0xa0406d4b, 0x522bee48,
- 0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957,
- 0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687,
- 0x0c38d26c, 0xfe53516f, 0xed03a29b, 0x1f682198,
- 0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927,
- 0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38,
- 0xdbfc821c, 0x2997011f, 0x3ac7f2eb, 0xc8ac71e8,
- 0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7,
- 0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096,
- 0xa65c047d, 0x5437877e, 0x4767748a, 0xb50cf789,
- 0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859,
- 0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46,
- 0x7198540d, 0x83f3d70e, 0x90a324fa, 0x62c8a7f9,
- 0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6,
- 0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36,
- 0x3cdb9bdd, 0xceb018de, 0xdde0eb2a, 0x2f8b6829,
- 0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c,
- 0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93,
- 0x082f63b7, 0xfa44e0b4, 0xe9141340, 0x1b7f9043,
- 0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c,
- 0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3,
- 0x55326b08, 0xa759e80b, 0xb4091bff, 0x466298fc,
- 0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c,
- 0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033,
- 0xa24bb5a6, 0x502036a5, 0x4370c551, 0xb11b4652,
- 0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d,
- 0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d,
- 0xef087a76, 0x1d63f975, 0x0e330a81, 0xfc588982,
- 0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d,
- 0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622,
- 0x38cc2a06, 0xcaa7a905, 0xd9f75af1, 0x2b9cd9f2,
- 0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed,
- 0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530,
- 0x0417b1db, 0xf67c32d8, 0xe52cc12c, 0x1747422f,
- 0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff,
- 0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0,
- 0xd3d3e1ab, 0x21b862a8, 0x32e8915c, 0xc083125f,
- 0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540,
- 0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90,
- 0x9e902e7b, 0x6cfbad78, 0x7fab5e8c, 0x8dc0dd8f,
- 0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee,
- 0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1,
- 0x69e9f0d5, 0x9b8273d6, 0x88d28022, 0x7ab90321,
- 0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e,
- 0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81,
- 0x34f4f86a, 0xc69f7b69, 0xd5cf889d, 0x27a40b9e,
- 0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e,
- 0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351,
-};
diff --git a/debian/changelog b/debian/changelog
deleted file mode 100644
index a2e894d..0000000
--- a/debian/changelog
+++ /dev/null
@@ -1,5 +0,0 @@
-fsverity-utils (0.1-1) experimental; urgency=low
-
- * Experimental: debian package for xfstests test appliances
-
- -- Eric Biggers <ebiggers@google.com> Mon, 02 Apr 2018 10:18:21 -0700
diff --git a/debian/compat b/debian/compat
deleted file mode 100644
index f599e28..0000000
--- a/debian/compat
+++ /dev/null
@@ -1 +0,0 @@
-10
diff --git a/debian/control b/debian/control
deleted file mode 100644
index aaa4ac3..0000000
--- a/debian/control
+++ /dev/null
@@ -1,14 +0,0 @@
-Source: fsverity-utils
-Priority: optional
-Maintainer: Eric Biggers <ebiggers@google.com>
-Build-Depends: debhelper (>= 10), libssl-dev (>= 1.0.0)
-Standards-Version: 4.0.0
-Vcs-Git: git://git.kernel.org/pub/scm/linux/kernel/git/mhalcrow/fsverity
-
-Package: fsverity-utils
-Section: utils
-Architecture: any
-Depends: ${shlibs:Depends}, ${misc:Depends}
-Description: fs-verity userspace utility. This program allows you to set up
- read-only, integrity and/or authenticity-protected files when supported by the
- underlying filesystem.
diff --git a/debian/copyright b/debian/copyright
deleted file mode 100644
index a728656..0000000
--- a/debian/copyright
+++ /dev/null
@@ -1,7 +0,0 @@
-Format: http://dep.debian.net/deps/dep5
-Upstream-Name: fsverity
-Source: git://git.kernel.org/pub/scm/linux/kernel/git/mhalcrow/fsverity
-
-Files: *
-Copyright: 2018 Google LLC
-License: GPL-2+
diff --git a/debian/rules b/debian/rules
deleted file mode 100755
index 9b694a1..0000000
--- a/debian/rules
+++ /dev/null
@@ -1,8 +0,0 @@
-#!/usr/bin/make -f
-
-export DH_VERBOSE=1
-
-include /usr/share/dpkg/default.mk
-
-%:
- dh $@
diff --git a/elide_patch.c b/elide_patch.c
deleted file mode 100644
index 3eed416..0000000
--- a/elide_patch.c
+++ /dev/null
@@ -1,307 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Elide and patch handling for 'fsverity setup'
- *
- * Copyright (C) 2018 Google LLC
- *
- * Written by Eric Biggers.
- */
-
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "fsverity_uapi.h"
-#include "fsveritysetup.h"
-
-/* An elision or a patch */
-struct fsverity_elide_patch {
- u64 offset; /* byte offset within the original data */
- u64 length; /* length in bytes */
- bool patch; /* false if elision, true if patch */
- u8 data[]; /* replacement data (if patch=true) */
-};
-
-/* Maximum supported patch size, in bytes */
-#define FS_VERITY_MAX_PATCH_SIZE 255
-
-/* Parse an --elide=OFFSET,LENGTH option */
-static struct fsverity_elide_patch *parse_elide_option(const char *optarg)
-{
- struct fsverity_elide_patch *ext = NULL;
- char *sep, *end;
- unsigned long long offset;
- unsigned long long length;
-
- sep = strchr(optarg, ',');
- if (!sep || sep == optarg)
- goto invalid;
- errno = 0;
- *sep = '\0';
- offset = strtoull(optarg, &end, 10);
- *sep = ',';
- if (errno || end != sep)
- goto invalid;
- length = strtoull(sep + 1, &end, 10);
- if (errno || *end)
- goto invalid;
- if (length <= 0 || length > UINT64_MAX - offset) {
- error_msg("Invalid length in '--elide=%s'", optarg);
- return NULL;
- }
- ext = xzalloc(sizeof(*ext));
- ext->offset = offset;
- ext->length = length;
- ext->patch = false;
- return ext;
-
-invalid:
- error_msg("Invalid --elide option: '%s'. Must be formatted as OFFSET,LENGTH",
- optarg);
- return NULL;
-}
-
-/* Parse a --patch=OFFSET,PATCHFILE option */
-static struct fsverity_elide_patch *parse_patch_option(const char *optarg)
-{
- struct fsverity_elide_patch *ext = NULL;
- struct filedes patchfile = { .fd = -1 };
- char *sep, *end;
- unsigned long long offset;
- u64 length;
-
- sep = strchr(optarg, ',');
- if (!sep || sep == optarg)
- goto invalid;
- errno = 0;
- *sep = '\0';
- offset = strtoull(optarg, &end, 10);
- *sep = ',';
- if (errno || end != sep)
- goto invalid;
- if (!open_file(&patchfile, sep + 1, O_RDONLY, 0))
- goto out;
- if (!get_file_size(&patchfile, &length))
- goto out;
- if (length <= 0) {
- error_msg("patch file '%s' is empty", patchfile.name);
- goto out;
- }
- if (length > FS_VERITY_MAX_PATCH_SIZE) {
- error_msg("Patch file '%s' is too long. Max patch size is %d bytes.",
- patchfile.name, FS_VERITY_MAX_PATCH_SIZE);
- goto out;
- }
- ext = xzalloc(sizeof(*ext) + length);
- ext->offset = offset;
- ext->length = length;
- ext->patch = true;
- if (!full_read(&patchfile, ext->data, length)) {
- free(ext);
- ext = NULL;
- }
-out:
- filedes_close(&patchfile);
- return ext;
-
-invalid:
- error_msg("Invalid --patch option: '%s'. Must be formatted as OFFSET,PATCHFILE",
- optarg);
- goto out;
-}
-
-/* Sort by increasing offset */
-static int cmp_elide_patch_exts(const void *_p1, const void *_p2)
-{
- const struct fsverity_elide_patch *ext1, *ext2;
-
- ext1 = *(const struct fsverity_elide_patch **)_p1;
- ext2 = *(const struct fsverity_elide_patch **)_p2;
-
- if (ext1->offset > ext2->offset)
- return 1;
- if (ext1->offset < ext2->offset)
- return -1;
- return 0;
-}
-
-/*
- * Given the lists of --elide and --patch options, validate and load the
- * elisions and patches into @params.
- */
-bool load_elisions_and_patches(const struct string_list *elide_opts,
- const struct string_list *patch_opts,
- struct fsveritysetup_params *params)
-{
- const size_t num_exts = elide_opts->length + patch_opts->length;
- struct fsverity_elide_patch **exts;
- size_t i, j;
-
- if (num_exts == 0) /* Normal case: no elisions or patches */
- return true;
- params->num_elisions_and_patches = num_exts;
- exts = xzalloc(num_exts * sizeof(exts[0]));
- params->elisions_and_patches = exts;
- j = 0;
-
- /* Parse the --elide options */
- for (i = 0; i < elide_opts->length; i++) {
- exts[j] = parse_elide_option(elide_opts->strings[i]);
- if (!exts[j++])
- return false;
- }
-
- /* Parse the --patch options */
- for (i = 0; i < patch_opts->length; i++) {
- exts[j] = parse_patch_option(patch_opts->strings[i]);
- if (!exts[j++])
- return false;
- }
-
- /* Sort the elisions and patches by increasing offset */
- qsort(exts, num_exts, sizeof(exts[0]), cmp_elide_patch_exts);
-
- /* Verify that no elisions or patches overlap */
- for (j = 1; j < num_exts; j++) {
- if (exts[j]->offset <
- exts[j - 1]->offset + exts[j - 1]->length) {
- error_msg("%s at [%"PRIu64", %"PRIu64") overlaps "
- "%s at [%"PRIu64", %"PRIu64")",
- exts[j - 1]->patch ? "Patch" : "Elision",
- exts[j - 1]->offset,
- exts[j - 1]->offset + exts[j - 1]->length,
- exts[j]->patch ? "patch" : "elision",
- exts[j]->offset,
- exts[j]->offset + exts[j]->length);
- return false;
- }
- }
- return true;
-}
-
-void free_elisions_and_patches(struct fsveritysetup_params *params)
-{
- size_t i;
-
- for (i = 0; i < params->num_elisions_and_patches; i++)
- free(params->elisions_and_patches[i]);
- free(params->elisions_and_patches);
-}
-
-/*
- * Given the original file @in of length @in_length bytes, create a temporary
- * file @out_ret and write to it the data with the elisions and patches applied,
- * with the end zero-padded to the next block boundary. Returns in
- * @out_length_ret the length of the elided/patched file in bytes.
- */
-bool apply_elisions_and_patches(const struct fsveritysetup_params *params,
- struct filedes *in, u64 in_length,
- struct filedes *out_ret, u64 *out_length_ret)
-{
- struct fsverity_elide_patch **exts = params->elisions_and_patches;
- struct filedes *out = out_ret;
- size_t i;
-
- for (i = 0; i < params->num_elisions_and_patches; i++) {
- if (exts[i]->offset + exts[i]->length > in_length) {
- error_msg("%s at [%"PRIu64", %"PRIu64") extends beyond end of input file",
- exts[i]->patch ? "Patch" : "Elision",
- exts[i]->offset,
- exts[i]->offset + exts[i]->length);
- return false;
- }
- }
-
- if (!filedes_seek(in, 0, SEEK_SET))
- return false;
-
- if (!open_tempfile(out))
- return false;
-
- for (i = 0; i < params->num_elisions_and_patches; i++) {
- printf("Applying %s: offset=%"PRIu64", length=%"PRIu64"\n",
- exts[i]->patch ? "patch" : "elision",
- exts[i]->offset, exts[i]->length);
-
- if (!copy_file_data(in, out, exts[i]->offset - in->pos))
- return false;
-
- if (exts[i]->patch &&
- !full_write(out, exts[i]->data, exts[i]->length))
- return false;
-
- if (!filedes_seek(in, exts[i]->length, SEEK_CUR))
- return false;
- }
- if (!copy_file_data(in, out, in_length - in->pos))
- return false;
- if (!write_zeroes(out, ALIGN(out->pos, params->blocksize) - out->pos))
- return false;
- *out_length_ret = out->pos;
- return true;
-}
-
-/* Calculate the size the elisions and patches will take up when serialized */
-size_t total_elide_patch_ext_length(const struct fsveritysetup_params *params)
-{
- size_t total = 0;
- size_t i;
-
- for (i = 0; i < params->num_elisions_and_patches; i++) {
- const struct fsverity_elide_patch *ext =
- params->elisions_and_patches[i];
- size_t inner_len;
-
- if (ext->patch) {
- inner_len = sizeof(struct fsverity_extension_patch) +
- ext->length;
- } else {
- inner_len = sizeof(struct fsverity_extension_elide);
- }
- total += FSVERITY_EXTLEN(inner_len);
- }
- return total;
-}
-
-/*
- * Append the elide and patch extensions (if any) to the given buffer.
- * The buffer must have enough space; call total_elide_patch_ext_length() first.
- */
-void append_elide_patch_exts(void **buf_p,
- const struct fsveritysetup_params *params)
-{
- void *buf = *buf_p;
- size_t i;
- union {
- struct {
- struct fsverity_extension_patch hdr;
- u8 data[FS_VERITY_MAX_PATCH_SIZE];
- } patch;
- struct fsverity_extension_elide elide;
- } u;
-
- for (i = 0; i < params->num_elisions_and_patches; i++) {
- const struct fsverity_elide_patch *ext =
- params->elisions_and_patches[i];
- int type;
- size_t extlen;
-
- if (ext->patch) {
- type = FS_VERITY_EXT_PATCH;
- u.patch.hdr.offset = cpu_to_le64(ext->offset);
- ASSERT(ext->length <= sizeof(u.patch.data));
- memcpy(u.patch.data, ext->data, ext->length);
- extlen = sizeof(u.patch.hdr) + ext->length;
- } else {
- type = FS_VERITY_EXT_ELIDE;
- u.elide.offset = cpu_to_le64(ext->offset),
- u.elide.length = cpu_to_le64(ext->length);
- extlen = sizeof(u.elide);
- }
- fsverity_append_extension(&buf, type, &u, extlen);
- }
-
- *buf_p = buf;
-}
diff --git a/fsverity.c b/fsverity.c
index a463c7f..6fabfa4 100644
--- a/fsverity.c
+++ b/fsverity.c
@@ -7,8 +7,10 @@
* Written by Eric Biggers.
*/
+#include <limits.h>
#include <stdlib.h>
#include <string.h>
+#include <unistd.h>
#include "commands.h"
#include "hash_algs.h"
@@ -22,26 +24,26 @@
{
.name = "enable",
.func = fsverity_cmd_enable,
- .short_desc =
-"Enable fs-verity on a file with verity metadata",
+ .short_desc = "Enable fs-verity on a file",
.usage_str =
" fsverity enable FILE\n"
+" [--hash-alg=HASH_ALG] [--block-size=BLOCK_SIZE] [--salt=SALT]\n"
+" [--signature=SIGFILE]\n"
}, {
.name = "measure",
.func = fsverity_cmd_measure,
.short_desc =
-"Display the measurement of the given fs-verity file(s)",
+"Display the measurement of the given verity file(s)",
.usage_str =
" fsverity measure FILE...\n"
}, {
- .name = "setup",
- .func = fsverity_cmd_setup,
- .short_desc = "Create the verity metadata for a file",
+ .name = "sign",
+ .func = fsverity_cmd_sign,
+ .short_desc = "Sign a file for fs-verity",
.usage_str =
-" fsverity setup INFILE [OUTFILE]\n"
-" [--hash=HASH_ALG] [--salt=SALT] [--signing-key=KEYFILE]\n"
-" [--signing-cert=CERTFILE] [--signature=SIGFILE]\n"
-" [--patch=OFFSET,PATCHFILE] [--elide=OFFSET,LENGTH]\n"
+" fsverity sign FILE OUT_SIGFILE --key=KEYFILE\n"
+" [--hash-alg=HASH_ALG] [--block-size=BLOCK_SIZE] [--salt=SALT]\n"
+" [--cert=CERTFILE]\n"
}
};
@@ -125,6 +127,52 @@
return NULL;
}
+bool parse_block_size_option(const char *arg, u32 *size_ptr)
+{
+ char *end;
+ unsigned long n = strtoul(arg, &end, 10);
+
+ if (*size_ptr != 0) {
+ error_msg("--block-size can only be specified once");
+ return false;
+ }
+
+ if (n <= 0 || n >= INT_MAX || !is_power_of_2(n) || *end != '\0') {
+ error_msg("Invalid block size: %s. Must be power of 2", arg);
+ return false;
+ }
+ *size_ptr = n;
+ return true;
+}
+
+bool parse_salt_option(const char *arg, u8 **salt_ptr, u32 *salt_size_ptr)
+{
+ if (*salt_ptr != NULL) {
+ error_msg("--salt can only be specified once");
+ return false;
+ }
+ *salt_size_ptr = strlen(arg) / 2;
+ *salt_ptr = xmalloc(*salt_size_ptr);
+ if (!hex2bin(arg, *salt_ptr, *salt_size_ptr)) {
+ error_msg("salt is not a valid hex string");
+ return false;
+ }
+ return true;
+}
+
+u32 get_default_block_size(void)
+{
+ long n = sysconf(_SC_PAGESIZE);
+
+ if (n <= 0 || n >= INT_MAX || !is_power_of_2(n)) {
+ fprintf(stderr,
+ "Warning: invalid _SC_PAGESIZE (%ld). Assuming 4K blocks.\n",
+ n);
+ return 4096;
+ }
+ return n;
+}
+
int main(int argc, char *argv[])
{
const struct fsverity_command *cmd;
diff --git a/fsverity_uapi.h b/fsverity_uapi.h
index 00c64f9..da0daf6 100644
--- a/fsverity_uapi.h
+++ b/fsverity_uapi.h
@@ -1,17 +1,32 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
- * fs-verity (file-based verity) support
+ * fs-verity user API
*
- * Copyright (C) 2018 Google LLC
+ * These ioctls can be used on filesystems that support fs-verity. See the
+ * "User API" section of Documentation/filesystems/fsverity.rst.
+ *
+ * Copyright 2019 Google LLC
*/
#ifndef _UAPI_LINUX_FSVERITY_H
#define _UAPI_LINUX_FSVERITY_H
-#include <linux/limits.h>
#include <linux/ioctl.h>
#include <linux/types.h>
-/* ========== Ioctls ========== */
+#define FS_VERITY_HASH_ALG_SHA256 1
+#define FS_VERITY_HASH_ALG_SHA512 2
+
+struct fsverity_enable_arg {
+ __u32 version;
+ __u32 hash_algorithm;
+ __u32 block_size;
+ __u32 salt_size;
+ __u64 salt_ptr;
+ __u32 sig_size;
+ __u32 __reserved1;
+ __u64 sig_ptr;
+ __u64 __reserved2[11];
+};
struct fsverity_digest {
__u16 digest_algorithm;
@@ -19,94 +34,7 @@
__u8 digest[];
};
-#define FS_IOC_ENABLE_VERITY _IO('f', 133)
+#define FS_IOC_ENABLE_VERITY _IOW('f', 133, struct fsverity_enable_arg)
#define FS_IOC_MEASURE_VERITY _IOWR('f', 134, struct fsverity_digest)
-/* ========== On-disk format ========== */
-
-#define FS_VERITY_MAGIC "FSVerity"
-
-/* Supported hash algorithms */
-#define FS_VERITY_ALG_SHA256 1
-#define FS_VERITY_ALG_SHA512 2
-#define FS_VERITY_ALG_CRC32C 3 /* for integrity only */
-
-/* Metadata stored near the end of fs-verity files, after the Merkle tree */
-/* This structure is 64 bytes long */
-struct fsverity_descriptor {
- __u8 magic[8]; /* must be FS_VERITY_MAGIC */
- __u8 major_version; /* must be 1 */
- __u8 minor_version; /* must be 0 */
- __u8 log_data_blocksize;/* log2(data-bytes-per-hash), e.g. 12 for 4KB */
- __u8 log_tree_blocksize;/* log2(tree-bytes-per-hash), e.g. 12 for 4KB */
- __le16 data_algorithm; /* hash algorithm for data blocks */
- __le16 tree_algorithm; /* hash algorithm for tree blocks */
- __le32 flags; /* flags */
- __le32 reserved1; /* must be 0 */
- __le64 orig_file_size; /* size of the original, unpadded data */
- __le16 auth_ext_count; /* number of authenticated extensions */
- __u8 reserved2[30]; /* must be 0 */
-};
-/* followed by list of 'auth_ext_count' authenticated extensions */
-/*
- * then followed by '__le16 unauth_ext_count' padded to next 8-byte boundary,
- * then a list of 'unauth_ext_count' (may be 0) unauthenticated extensions
- */
-
-/* Extension types */
-#define FS_VERITY_EXT_ROOT_HASH 1
-#define FS_VERITY_EXT_SALT 2
-#define FS_VERITY_EXT_PKCS7_SIGNATURE 3
-#define FS_VERITY_EXT_ELIDE 4
-#define FS_VERITY_EXT_PATCH 5
-
-/* Header of each extension (variable-length metadata item) */
-struct fsverity_extension {
- /*
- * Length in bytes, including this header but excluding padding to next
- * 8-byte boundary that is applied when advancing to the next extension.
- */
- __le32 length;
- __le16 type; /* Type of this extension (see codes above) */
- __le16 reserved; /* Reserved, must be 0 */
-};
-/* followed by the payload of 'length - 8' bytes */
-
-/* Extension payload formats */
-
-/*
- * FS_VERITY_EXT_ROOT_HASH payload is just a byte array, with size equal to the
- * digest size of the hash algorithm given in the fsverity_descriptor
- */
-
-/* FS_VERITY_EXT_SALT payload is just a byte array, any size */
-
-/*
- * FS_VERITY_EXT_PKCS7_SIGNATURE payload is a DER-encoded PKCS#7 message
- * containing the signed file measurement in the following format:
- */
-struct fsverity_digest_disk {
- __le16 digest_algorithm;
- __le16 digest_size;
- __u8 digest[];
-};
-
-/* FS_VERITY_EXT_ELIDE payload */
-struct fsverity_extension_elide {
- __le64 offset;
- __le64 length;
-};
-
-/* FS_VERITY_EXT_PATCH payload */
-struct fsverity_extension_patch {
- __le64 offset;
- /* followed by variable-length patch data */
-};
-
-/* Fields stored at the very end of the file */
-struct fsverity_footer {
- __le32 desc_reverse_offset; /* distance to fsverity_descriptor */
- __u8 magic[8]; /* FS_VERITY_MAGIC */
-} __attribute__((packed));
-
#endif /* _UAPI_LINUX_FSVERITY_H */
diff --git a/fsveritysetup.h b/fsveritysetup.h
deleted file mode 100644
index 282aabd..0000000
--- a/fsveritysetup.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
-#ifndef FSVERITYSETUP_H
-#define FSVERITYSETUP_H
-
-#include "util.h"
-
-struct fsveritysetup_params {
- const struct fsverity_hash_alg *hash_alg;
- u8 *salt;
- size_t saltlen;
- int blocksize;
- int blockbits; /* ilog2(blocksize) */
- unsigned int hashes_per_block; /* blocksize / digest_size */
- const char *signing_key_file;
- const char *signing_cert_file;
- const char *signature_file;
- struct fsverity_elide_patch **elisions_and_patches;
- size_t num_elisions_and_patches;
-};
-
-void fsverity_append_extension(void **buf_p, int type,
- const void *ext, size_t extlen);
-
-#define FSVERITY_EXTLEN(inner_len) \
- ALIGN(sizeof(struct fsverity_extension) + (inner_len), 8)
-
-/* elide_patch.c */
-bool load_elisions_and_patches(const struct string_list *elide_opts,
- const struct string_list *patch_opts,
- struct fsveritysetup_params *params);
-void free_elisions_and_patches(struct fsveritysetup_params *params);
-bool apply_elisions_and_patches(const struct fsveritysetup_params *params,
- struct filedes *in, u64 in_length,
- struct filedes *out_ret, u64 *out_length_ret);
-size_t total_elide_patch_ext_length(const struct fsveritysetup_params *params);
-void append_elide_patch_exts(void **buf_p,
- const struct fsveritysetup_params *params);
-/* sign.c */
-int append_signed_measurement(struct filedes *out,
- const struct fsveritysetup_params *params,
- const u8 *measurement);
-
-#endif /* FSVERITYSETUP_H */
diff --git a/hash_algs.c b/hash_algs.c
index 1e46924..7251bf2 100644
--- a/hash_algs.c
+++ b/hash_algs.c
@@ -14,11 +14,6 @@
#include "fsverity_uapi.h"
#include "hash_algs.h"
-static void free_hash_ctx(struct hash_ctx *ctx)
-{
- free(ctx);
-}
-
/* ========== libcrypto (OpenSSL) wrappers ========== */
struct openssl_hash_ctx {
@@ -104,79 +99,21 @@
return openssl_digest_ctx_create(alg, EVP_sha512());
}
-/* ========== CRC-32C ========== */
-
-/*
- * There are faster ways to calculate CRC's, but for now we just use the
- * 256-entry table method as it's portable and not too complex.
- */
-
-#include "crc32c_table.h"
-
-struct crc32c_hash_ctx {
- struct hash_ctx base; /* must be first */
- u32 remainder;
-};
-
-static void crc32c_init(struct hash_ctx *_ctx)
-{
- struct crc32c_hash_ctx *ctx = (void *)_ctx;
-
- ctx->remainder = ~0;
-}
-
-static void crc32c_update(struct hash_ctx *_ctx, const void *data, size_t size)
-{
- struct crc32c_hash_ctx *ctx = (void *)_ctx;
- const u8 *p = data;
- u32 r = ctx->remainder;
-
- while (size--)
- r = (r >> 8) ^ crc32c_table[(u8)r ^ *p++];
-
- ctx->remainder = r;
-}
-
-static void crc32c_final(struct hash_ctx *_ctx, u8 *digest)
-{
- struct crc32c_hash_ctx *ctx = (void *)_ctx;
- __le32 remainder = cpu_to_le32(~ctx->remainder);
-
- memcpy(digest, &remainder, sizeof(remainder));
-}
-
-static struct hash_ctx *create_crc32c_ctx(const struct fsverity_hash_alg *alg)
-{
- struct crc32c_hash_ctx *ctx = xzalloc(sizeof(*ctx));
-
- ctx->base.alg = alg;
- ctx->base.init = crc32c_init;
- ctx->base.update = crc32c_update;
- ctx->base.final = crc32c_final;
- ctx->base.free = free_hash_ctx;
- return &ctx->base;
-}
-
/* ========== Hash algorithm definitions ========== */
const struct fsverity_hash_alg fsverity_hash_algs[] = {
- [FS_VERITY_ALG_SHA256] = {
+ [FS_VERITY_HASH_ALG_SHA256] = {
.name = "sha256",
.digest_size = 32,
- .cryptographic = true,
+ .block_size = 64,
.create_ctx = create_sha256_ctx,
},
- [FS_VERITY_ALG_SHA512] = {
+ [FS_VERITY_HASH_ALG_SHA512] = {
.name = "sha512",
.digest_size = 64,
- .cryptographic = true,
+ .block_size = 128,
.create_ctx = create_sha512_ctx,
},
- [FS_VERITY_ALG_CRC32C] = {
- .name = "crc32c",
- .digest_size = 4,
- .create_ctx = create_crc32c_ctx,
- },
};
const struct fsverity_hash_alg *find_hash_alg_by_name(const char *name)
@@ -216,3 +153,11 @@
}
}
}
+
+/* ->init(), ->update(), and ->final() all in one step */
+void hash_full(struct hash_ctx *ctx, const void *data, size_t size, u8 *digest)
+{
+ hash_init(ctx);
+ hash_update(ctx, data, size);
+ hash_final(ctx, digest);
+}
diff --git a/hash_algs.h b/hash_algs.h
index 3cb0a98..3e90f49 100644
--- a/hash_algs.h
+++ b/hash_algs.h
@@ -9,7 +9,7 @@
struct fsverity_hash_alg {
const char *name;
unsigned int digest_size;
- bool cryptographic;
+ unsigned int block_size;
struct hash_ctx *(*create_ctx)(const struct fsverity_hash_alg *alg);
};
@@ -26,7 +26,9 @@
const struct fsverity_hash_alg *find_hash_alg_by_name(const char *name);
const struct fsverity_hash_alg *find_hash_alg_by_num(unsigned int num);
void show_all_hash_algs(FILE *fp);
-#define DEFAULT_HASH_ALG (&fsverity_hash_algs[FS_VERITY_ALG_SHA256])
+
+/* The hash algorithm that fsverity-utils assumes when none is specified */
+#define FS_VERITY_HASH_ALG_DEFAULT FS_VERITY_HASH_ALG_SHA256
/*
* Largest digest size among all hash algorithms supported by fs-verity.
@@ -61,4 +63,6 @@
ctx->free(ctx);
}
+void hash_full(struct hash_ctx *ctx, const void *data, size_t size, u8 *digest);
+
#endif /* HASH_ALGS_H */
diff --git a/scripts/gen_crc32c_table.c b/scripts/gen_crc32c_table.c
deleted file mode 100644
index 656a349..0000000
--- a/scripts/gen_crc32c_table.c
+++ /dev/null
@@ -1,64 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Generate a table for CRC-32C calculation.
- *
- * Copyright (C) 2018 Google LLC
- *
- * Written by Eric Biggers.
- */
-
-#include <stdint.h>
-#include <stdio.h>
-
-/*
- * This is the CRC-32C (Castagnoli) polynomial: x^32+x^28+x^27+x^26+x^25+x^23+
- * x^22+x^20+x^19+x^18+x^14+x^13+x^11+x^10+x^9+x^8+x^6+x^0, with the polynomial
- * coefficients mapped to bits using the "little endian" convention.
- */
-#define CRC32C_POLY_LE 0x82F63B78
-
-static uint32_t crc32c_update_bit(uint32_t remainder, uint8_t bit)
-{
- return (remainder >> 1) ^
- (((remainder ^ bit) & 1) ? CRC32C_POLY_LE : 0);
-}
-
-static uint32_t crc32c_update_byte(uint32_t remainder, uint8_t byte)
-{
- int bit;
-
- for (bit = 0; bit < 8; bit++, byte >>= 1)
- remainder = crc32c_update_bit(remainder, byte & 1);
- return remainder;
-}
-
-static uint32_t crc32c_table[256];
-
-int main(void)
-{
- int i, j;
-
- for (i = 0; i < 256; i++)
- crc32c_table[i] = crc32c_update_byte(0, i);
-
- printf("/*\n");
- printf(" * crc32c_table.h - data table to accelerate CRC-32C computation\n");
- printf(" *\n");
- printf(" * This file was automatically generated by scripts/gen_crc32c_table.c\n");
- printf(" */\n");
- printf("\n");
- printf("#include <stdint.h>\n");
- printf("\n");
- printf("static const uint32_t crc32c_table[] = {\n");
- for (i = 0; i < 64; i++) {
- printf("\t");
- for (j = 0; j < 4; j++) {
- printf("0x%08x,", crc32c_table[i * 4 + j]);
- if (j != 3)
- printf(" ");
- }
- printf("\n");
- }
- printf("};\n");
- return 0;
-}
diff --git a/sign.c b/sign.c
deleted file mode 100644
index 20fecfa..0000000
--- a/sign.c
+++ /dev/null
@@ -1,552 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Signature support for 'fsverity setup'
- *
- * Copyright (C) 2018 Google LLC
- *
- * Written by Eric Biggers.
- */
-
-#include <fcntl.h>
-#include <limits.h>
-#include <openssl/bio.h>
-#include <openssl/err.h>
-#include <openssl/pem.h>
-#include <openssl/pkcs7.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "fsverity_uapi.h"
-#include "fsveritysetup.h"
-#include "hash_algs.h"
-
-static void __printf(1, 2) __cold
-error_msg_openssl(const char *format, ...)
-{
- va_list va;
-
- va_start(va, format);
- do_error_msg(format, va, 0);
- va_end(va);
-
- if (ERR_peek_error() == 0)
- return;
-
- fprintf(stderr, "OpenSSL library errors:\n");
- ERR_print_errors_fp(stderr);
-}
-
-/* Read a PEM PKCS#8 formatted private key */
-static EVP_PKEY *read_private_key(const char *keyfile)
-{
- BIO *bio;
- EVP_PKEY *pkey;
-
- bio = BIO_new_file(keyfile, "r");
- if (!bio) {
- error_msg_openssl("can't open '%s' for reading", keyfile);
- return NULL;
- }
-
- pkey = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);
- if (!pkey) {
- error_msg_openssl("Failed to parse private key file '%s'.\n"
- " Note: it must be in PEM PKCS#8 format.",
- keyfile);
- }
- BIO_free(bio);
- return pkey;
-}
-
-/* Read a PEM X.509 formatted certificate */
-static X509 *read_certificate(const char *certfile)
-{
- BIO *bio;
- X509 *cert;
-
- bio = BIO_new_file(certfile, "r");
- if (!bio) {
- error_msg_openssl("can't open '%s' for reading", certfile);
- return NULL;
- }
- cert = PEM_read_bio_X509(bio, NULL, NULL, NULL);
- if (!cert) {
- error_msg_openssl("Failed to parse X.509 certificate file '%s'.\n"
- " Note: it must be in PEM format.",
- certfile);
- }
- BIO_free(bio);
- return cert;
-}
-
-/*
- * Check that the given data is a valid 'struct fsverity_digest_disk' that
- * matches the given @expected_digest and @hash_alg.
- *
- * Return: NULL if the digests match, else a string describing the difference.
- */
-static const char *
-compare_fsverity_digest(const void *data, size_t size,
- const u8 *expected_digest,
- const struct fsverity_hash_alg *hash_alg)
-{
- const struct fsverity_digest_disk *d = data;
-
- if (size != sizeof(*d) + hash_alg->digest_size)
- return "unexpected length";
-
- if (le16_to_cpu(d->digest_algorithm) != hash_alg - fsverity_hash_algs)
- return "unexpected hash algorithm";
-
- if (le16_to_cpu(d->digest_size) != hash_alg->digest_size)
- return "wrong digest size for hash algorithm";
-
- if (memcmp(expected_digest, d->digest, hash_alg->digest_size))
- return "wrong digest";
-
- return NULL;
-}
-
-#ifdef OPENSSL_IS_BORINGSSL
-
-static bool sign_pkcs7(const void *data_to_sign, size_t data_size,
- EVP_PKEY *pkey, X509 *cert, const EVP_MD *md,
- void **sig_ret, int *sig_size_ret)
-{
- CBB out, outer_seq, wrapped_seq, seq, digest_algos_set, digest_algo,
- null, content_info, issuer_and_serial, signed_data,
- wrapped_signed_data, signer_infos, signer_info, sign_algo,
- signature;
- EVP_MD_CTX md_ctx;
- u8 *name_der = NULL, *sig = NULL, *pkcs7_data = NULL;
- size_t pkcs7_data_len, sig_len;
- int name_der_len, sig_nid;
- bool ok = false;
-
- EVP_MD_CTX_init(&md_ctx);
- BIGNUM *serial = ASN1_INTEGER_to_BN(X509_get_serialNumber(cert), NULL);
-
- if (!CBB_init(&out, 1024)) {
- error_msg("out of memory");
- goto out;
- }
-
- name_der_len = i2d_X509_NAME(X509_get_subject_name(cert), &name_der);
- if (name_der_len < 0) {
- error_msg_openssl("i2d_X509_NAME failed");
- goto out;
- }
-
- if (!EVP_DigestSignInit(&md_ctx, NULL, md, NULL, pkey)) {
- error_msg_openssl("EVP_DigestSignInit failed");
- goto out;
- }
-
- sig_len = EVP_PKEY_size(pkey);
- sig = xmalloc(sig_len);
- if (!EVP_DigestSign(&md_ctx, sig, &sig_len, data_to_sign, data_size)) {
- error_msg_openssl("EVP_DigestSign failed");
- goto out;
- }
-
- sig_nid = EVP_PKEY_id(pkey);
- /* To mirror OpenSSL behaviour, always use |NID_rsaEncryption| with RSA
- * rather than the combined hash+pkey NID. */
- if (sig_nid != NID_rsaEncryption) {
- OBJ_find_sigid_by_algs(&sig_nid, EVP_MD_type(md),
- EVP_PKEY_id(pkey));
- }
-
- // See https://tools.ietf.org/html/rfc2315#section-7
- if (!CBB_add_asn1(&out, &outer_seq, CBS_ASN1_SEQUENCE) ||
- !OBJ_nid2cbb(&outer_seq, NID_pkcs7_signed) ||
- !CBB_add_asn1(&outer_seq, &wrapped_seq, CBS_ASN1_CONTEXT_SPECIFIC |
- CBS_ASN1_CONSTRUCTED | 0) ||
- // See https://tools.ietf.org/html/rfc2315#section-9.1
- !CBB_add_asn1(&wrapped_seq, &seq, CBS_ASN1_SEQUENCE) ||
- !CBB_add_asn1_uint64(&seq, 1 /* version */) ||
- !CBB_add_asn1(&seq, &digest_algos_set, CBS_ASN1_SET) ||
- !CBB_add_asn1(&digest_algos_set, &digest_algo, CBS_ASN1_SEQUENCE) ||
- !OBJ_nid2cbb(&digest_algo, EVP_MD_type(md)) ||
- !CBB_add_asn1(&digest_algo, &null, CBS_ASN1_NULL) ||
- !CBB_add_asn1(&seq, &content_info, CBS_ASN1_SEQUENCE) ||
- !OBJ_nid2cbb(&content_info, NID_pkcs7_data) ||
- !CBB_add_asn1(
- &content_info, &signed_data,
- CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
- !CBB_add_asn1(&signed_data, &wrapped_signed_data,
- CBS_ASN1_OCTETSTRING) ||
- !CBB_add_bytes(&wrapped_signed_data, (const u8 *)data_to_sign,
- data_size) ||
- !CBB_add_asn1(&seq, &signer_infos, CBS_ASN1_SET) ||
- !CBB_add_asn1(&signer_infos, &signer_info, CBS_ASN1_SEQUENCE) ||
- !CBB_add_asn1_uint64(&signer_info, 1 /* version */) ||
- !CBB_add_asn1(&signer_info, &issuer_and_serial,
- CBS_ASN1_SEQUENCE) ||
- !CBB_add_bytes(&issuer_and_serial, name_der, name_der_len) ||
- !BN_marshal_asn1(&issuer_and_serial, serial) ||
- !CBB_add_asn1(&signer_info, &digest_algo, CBS_ASN1_SEQUENCE) ||
- !OBJ_nid2cbb(&digest_algo, EVP_MD_type(md)) ||
- !CBB_add_asn1(&digest_algo, &null, CBS_ASN1_NULL) ||
- !CBB_add_asn1(&signer_info, &sign_algo, CBS_ASN1_SEQUENCE) ||
- !OBJ_nid2cbb(&sign_algo, sig_nid) ||
- !CBB_add_asn1(&sign_algo, &null, CBS_ASN1_NULL) ||
- !CBB_add_asn1(&signer_info, &signature, CBS_ASN1_OCTETSTRING) ||
- !CBB_add_bytes(&signature, sig, sig_len) ||
- !CBB_finish(&out, &pkcs7_data, &pkcs7_data_len)) {
- error_msg_openssl("failed to construct PKCS#7 data");
- goto out;
- }
-
- *sig_ret = xmemdup(pkcs7_data, pkcs7_data_len);
- *sig_size_ret = pkcs7_data_len;
- ok = true;
-out:
- BN_free(serial);
- EVP_MD_CTX_cleanup(&md_ctx);
- CBB_cleanup(&out);
- free(sig);
- OPENSSL_free(name_der);
- OPENSSL_free(pkcs7_data);
- return ok;
-}
-
-static const char *
-compare_fsverity_digest_pkcs7(const void *sig, size_t sig_len,
- const u8 *expected_measurement,
- const struct fsverity_hash_alg *hash_alg)
-{
- CBS in, content_info, content_type, wrapped_signed_data, signed_data,
- content, wrapped_data, data;
- u64 version;
-
- CBS_init(&in, sig, sig_len);
- if (!CBS_get_asn1(&in, &content_info, CBS_ASN1_SEQUENCE) ||
- !CBS_get_asn1(&content_info, &content_type, CBS_ASN1_OBJECT) ||
- (OBJ_cbs2nid(&content_type) != NID_pkcs7_signed) ||
- !CBS_get_asn1(
- &content_info, &wrapped_signed_data,
- CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
- !CBS_get_asn1(&wrapped_signed_data, &signed_data,
- CBS_ASN1_SEQUENCE) ||
- !CBS_get_asn1_uint64(&signed_data, &version) ||
- (version < 1) ||
- !CBS_get_asn1(&signed_data, NULL /* digests */, CBS_ASN1_SET) ||
- !CBS_get_asn1(&signed_data, &content, CBS_ASN1_SEQUENCE) ||
- !CBS_get_asn1(&content, &content_type, CBS_ASN1_OBJECT) ||
- (OBJ_cbs2nid(&content_type) != NID_pkcs7_data) ||
- !CBS_get_asn1(&content, &wrapped_data, CBS_ASN1_CONTEXT_SPECIFIC |
- CBS_ASN1_CONSTRUCTED | 0) ||
- !CBS_get_asn1(&wrapped_data, &data, CBS_ASN1_OCTETSTRING)) {
- return "invalid PKCS#7 data";
- }
-
- return compare_fsverity_digest(CBS_data(&data), CBS_len(&data),
- expected_measurement, hash_alg);
-}
-
-#else /* OPENSSL_IS_BORINGSSL */
-
-static BIO *new_mem_buf(const void *buf, size_t size)
-{
- BIO *bio;
-
- ASSERT(size <= INT_MAX);
- /*
- * Prior to OpenSSL 1.1.0, BIO_new_mem_buf() took a non-const pointer,
- * despite still marking the resulting bio as read-only. So cast away
- * the const to avoid a compiler warning with older OpenSSL versions.
- */
- bio = BIO_new_mem_buf((void *)buf, size);
- if (!bio)
- error_msg_openssl("out of memory");
- return bio;
-}
-
-static bool sign_pkcs7(const void *data_to_sign, size_t data_size,
- EVP_PKEY *pkey, X509 *cert, const EVP_MD *md,
- void **sig_ret, int *sig_size_ret)
-{
- /*
- * PKCS#7 signing flags:
- *
- * - PKCS7_BINARY signing binary data, so skip MIME translation
- *
- * - PKCS7_NOATTR omit extra authenticated attributes, such as
- * SMIMECapabilities
- *
- * - PKCS7_NOCERTS omit the signer's certificate
- *
- * - PKCS7_PARTIAL PKCS7_sign() creates a handle only, then
- * PKCS7_sign_add_signer() can add a signer later.
- * This is necessary to change the message digest
- * algorithm from the default of SHA-1. Requires
- * OpenSSL 1.0.0 or later.
- */
- int pkcs7_flags = PKCS7_BINARY | PKCS7_NOATTR | PKCS7_NOCERTS |
- PKCS7_PARTIAL;
- void *sig;
- int sig_size;
- BIO *bio = NULL;
- PKCS7 *p7 = NULL;
- bool ok = false;
-
- bio = new_mem_buf(data_to_sign, data_size);
- if (!bio)
- goto out;
-
- p7 = PKCS7_sign(NULL, NULL, NULL, bio, pkcs7_flags);
- if (!p7) {
- error_msg_openssl("failed to initialize PKCS#7 signature object");
- goto out;
- }
-
- if (!PKCS7_sign_add_signer(p7, cert, pkey, md, pkcs7_flags)) {
- error_msg_openssl("failed to add signer to PKCS#7 signature object");
- goto out;
- }
-
- if (PKCS7_final(p7, bio, pkcs7_flags) != 1) {
- error_msg_openssl("failed to finalize PKCS#7 signature");
- goto out;
- }
-
- BIO_free(bio);
- bio = BIO_new(BIO_s_mem());
- if (!bio) {
- error_msg_openssl("out of memory");
- goto out;
- }
-
- if (i2d_PKCS7_bio(bio, p7) != 1) {
- error_msg_openssl("failed to DER-encode PKCS#7 signature object");
- goto out;
- }
-
- sig_size = BIO_get_mem_data(bio, &sig);
- *sig_ret = xmemdup(sig, sig_size);
- *sig_size_ret = sig_size;
- ok = true;
-out:
- PKCS7_free(p7);
- BIO_free(bio);
- return ok;
-}
-
-static const char *
-compare_fsverity_digest_pkcs7(const void *sig, size_t sig_len,
- const u8 *expected_measurement,
- const struct fsverity_hash_alg *hash_alg)
-{
- BIO *bio = NULL;
- PKCS7 *p7 = NULL;
- const char *reason = NULL;
-
- bio = new_mem_buf(sig, sig_len);
- if (!bio)
- return "out of memory";
-
- p7 = d2i_PKCS7_bio(bio, NULL);
- if (!p7) {
- reason = "failed to decode PKCS#7 signature";
- goto out;
- }
-
- if (OBJ_obj2nid(p7->type) != NID_pkcs7_signed ||
- OBJ_obj2nid(p7->d.sign->contents->type) != NID_pkcs7_data) {
- reason = "unexpected PKCS#7 content type";
- } else {
- const ASN1_OCTET_STRING *o = p7->d.sign->contents->d.data;
-
- reason = compare_fsverity_digest(o->data, o->length,
- expected_measurement,
- hash_alg);
- }
-out:
- BIO_free(bio);
- PKCS7_free(p7);
- return reason;
-}
-
-#endif /* !OPENSSL_IS_BORINGSSL */
-
-/*
- * Sign the specified @data_to_sign of length @data_size bytes using the private
- * key in @keyfile, the certificate in @certfile, and the hash algorithm
- * @hash_alg. Returns the DER-formatted PKCS#7 signature, with the signed data
- * included (not detached), in @sig_ret and @sig_size_ret.
- */
-static bool sign_data(const void *data_to_sign, size_t data_size,
- const char *keyfile, const char *certfile,
- const struct fsverity_hash_alg *hash_alg,
- void **sig_ret, int *sig_size_ret)
-{
- EVP_PKEY *pkey = NULL;
- X509 *cert = NULL;
- const EVP_MD *md;
- bool ok = false;
-
- pkey = read_private_key(keyfile);
- if (!pkey)
- goto out;
-
- cert = read_certificate(certfile);
- if (!cert)
- goto out;
-
- OpenSSL_add_all_digests();
- ASSERT(hash_alg->cryptographic);
- md = EVP_get_digestbyname(hash_alg->name);
- if (!md) {
- fprintf(stderr,
- "Warning: '%s' algorithm not found in OpenSSL library.\n"
- " Falling back to SHA-256 signature.\n",
- hash_alg->name);
- md = EVP_sha256();
- }
-
- ok = sign_pkcs7(data_to_sign, data_size, pkey, cert, md,
- sig_ret, sig_size_ret);
-out:
- EVP_PKEY_free(pkey);
- X509_free(cert);
- return ok;
-}
-
-/*
- * Read a file measurement signature in PKCS#7 DER format from @signature_file,
- * validate that the signed data matches the expected measurement, then return
- * the PKCS#7 DER message in @sig_ret and @sig_size_ret.
- */
-static bool read_signature(const char *signature_file,
- const u8 *expected_measurement,
- const struct fsverity_hash_alg *hash_alg,
- void **sig_ret, int *sig_size_ret)
-{
- struct filedes file = { .fd = -1 };
- u64 filesize;
- void *sig = NULL;
- bool ok = false;
- const char *reason;
-
- if (!open_file(&file, signature_file, O_RDONLY, 0))
- goto out;
- if (!get_file_size(&file, &filesize))
- goto out;
- if (filesize <= 0) {
- error_msg("signature file '%s' is empty", signature_file);
- goto out;
- }
- if (filesize > 1000000) {
- error_msg("signature file '%s' is too large", signature_file);
- goto out;
- }
- sig = xmalloc(filesize);
- if (!full_read(&file, sig, filesize))
- goto out;
-
- reason = compare_fsverity_digest_pkcs7(sig, filesize,
- expected_measurement, hash_alg);
- if (reason) {
- error_msg("signed file measurement from '%s' is invalid (%s)",
- signature_file, reason);
- goto out;
- }
-
- printf("Using existing signed file measurement from '%s'\n",
- signature_file);
- *sig_ret = sig;
- *sig_size_ret = filesize;
- sig = NULL;
- ok = true;
-out:
- filedes_close(&file);
- free(sig);
- return ok;
-}
-
-static bool write_signature(const char *signature_file,
- const void *sig, int sig_size)
-{
- struct filedes file;
- bool ok;
-
- if (!open_file(&file, signature_file, O_WRONLY|O_CREAT|O_TRUNC, 0644))
- return false;
- ok = full_write(&file, sig, sig_size);
- ok &= filedes_close(&file);
- if (ok)
- printf("Wrote signed file measurement to '%s'\n",
- signature_file);
- return ok;
-}
-
-/*
- * Append the signed file measurement to the output file as a PKCS7_SIGNATURE
- * extension item.
- *
- * Return: exit status code (0 on success, nonzero on failure)
- */
-int append_signed_measurement(struct filedes *out,
- const struct fsveritysetup_params *params,
- const u8 *measurement)
-{
- struct fsverity_digest_disk *data_to_sign = NULL;
- void *sig = NULL;
- void *extbuf = NULL;
- void *tmp;
- int sig_size;
- int status;
-
- if (params->signing_key_file) {
- size_t data_size = sizeof(*data_to_sign) +
- params->hash_alg->digest_size;
-
- /* Sign the file measurement using the given key */
-
- data_to_sign = xzalloc(data_size);
- data_to_sign->digest_algorithm =
- cpu_to_le16(params->hash_alg - fsverity_hash_algs);
- data_to_sign->digest_size =
- cpu_to_le16(params->hash_alg->digest_size);
- memcpy(data_to_sign->digest, measurement,
- params->hash_alg->digest_size);
-
- ASSERT(compare_fsverity_digest(data_to_sign, data_size,
- measurement, params->hash_alg) == NULL);
-
- if (!sign_data(data_to_sign, data_size,
- params->signing_key_file,
- params->signing_cert_file ?:
- params->signing_key_file,
- params->hash_alg,
- &sig, &sig_size))
- goto out_err;
-
- if (params->signature_file &&
- !write_signature(params->signature_file, sig, sig_size))
- goto out_err;
- } else {
- /* Using a signature that was already created */
- if (!read_signature(params->signature_file, measurement,
- params->hash_alg, &sig, &sig_size))
- goto out_err;
- }
-
- tmp = extbuf = xzalloc(FSVERITY_EXTLEN(sig_size));
- fsverity_append_extension(&tmp, FS_VERITY_EXT_PKCS7_SIGNATURE,
- sig, sig_size);
- ASSERT(tmp == extbuf + FSVERITY_EXTLEN(sig_size));
- if (!full_write(out, extbuf, FSVERITY_EXTLEN(sig_size)))
- goto out_err;
- status = 0;
-out:
- free(data_to_sign);
- free(sig);
- free(extbuf);
- return status;
-
-out_err:
- status = 1;
- goto out;
-}
diff --git a/util.c b/util.c
index 58a2a60..2218f2e 100644
--- a/util.c
+++ b/util.c
@@ -45,26 +45,6 @@
return xmemdup(s, strlen(s) + 1);
}
-char *xasprintf(const char *format, ...)
-{
- va_list va1, va2;
- int size;
- char *s;
-
- va_start(va1, format);
-
- va_copy(va2, va1);
- size = vsnprintf(NULL, 0, format, va2);
- va_end(va2);
-
- ASSERT(size >= 0);
- s = xmalloc(size + 1);
- vsprintf(s, format, va1);
-
- va_end(va1);
- return s;
-}
-
/* ========== Error messages and assertions ========== */
void do_error_msg(const char *format, va_list va, int err)
@@ -121,26 +101,7 @@
"reading and writing");
return false;
}
- file->autodelete = false;
file->name = xstrdup(filename);
- file->pos = 0;
- return true;
-}
-
-bool open_tempfile(struct filedes *file)
-{
- const char *tmpdir = getenv("TMPDIR") ?: P_tmpdir;
- char *name = xasprintf("%s/fsverity-XXXXXX", tmpdir);
-
- file->fd = mkstemp(name);
- if (file->fd < 0) {
- error_msg_errno("can't create temporary file");
- free(name);
- return false;
- }
- file->autodelete = true;
- file->name = name;
- file->pos = 0;
return true;
}
@@ -156,19 +117,6 @@
return true;
}
-bool filedes_seek(struct filedes *file, u64 pos, int whence)
-{
- off_t res;
-
- res = lseek(file->fd, pos, whence);
- if (res < 0) {
- error_msg_errno("seek error on '%s'", file->name);
- return false;
- }
- file->pos = res;
- return true;
-}
-
bool full_read(struct filedes *file, void *buf, size_t count)
{
while (count) {
@@ -184,27 +132,6 @@
}
buf += n;
count -= n;
- file->pos += n;
- }
- return true;
-}
-
-bool full_pread(struct filedes *file, void *buf, size_t count, u64 offset)
-{
- while (count) {
- int n = pread(file->fd, buf, min(count, INT_MAX), offset);
-
- if (n < 0) {
- error_msg_errno("reading from '%s'", file->name);
- return false;
- }
- if (n == 0) {
- error_msg("unexpected end-of-file on '%s'", file->name);
- return false;
- }
- buf += n;
- count -= n;
- offset += n;
}
return true;
}
@@ -220,58 +147,6 @@
}
buf += n;
count -= n;
- file->pos += n;
- }
- return true;
-}
-
-bool full_pwrite(struct filedes *file, const void *buf, size_t count,
- u64 offset)
-{
- while (count) {
- int n = pwrite(file->fd, buf, min(count, INT_MAX), offset);
-
- if (n < 0) {
- error_msg_errno("writing to '%s'", file->name);
- return false;
- }
- buf += n;
- count -= n;
- offset += n;
- }
- return true;
-}
-
-/* Copy 'count' bytes of data from 'src' to 'dst' */
-bool copy_file_data(struct filedes *src, struct filedes *dst, u64 count)
-{
- char buf[4096];
-
- while (count) {
- size_t n = min(count, sizeof(buf));
-
- if (!full_read(src, buf, n))
- return false;
- if (!full_write(dst, buf, n))
- return false;
- count -= n;
- }
- return true;
-}
-
-/* Write 'count' bytes of zeroes to the file */
-bool write_zeroes(struct filedes *file, u64 count)
-{
- char buf[4096];
-
- memset(buf, 0, min(count, sizeof(buf)));
-
- while (count) {
- size_t n = min(count, sizeof(buf));
-
- if (!full_write(file, buf, n))
- return false;
- count -= n;
}
return true;
}
@@ -285,8 +160,6 @@
res = close(file->fd);
if (res != 0)
error_msg_errno("closing '%s'", file->name);
- if (file->autodelete)
- (void)unlink(file->name);
file->fd = -1;
free(file->name);
file->name = NULL;
@@ -340,23 +213,3 @@
}
*hex = '\0';
}
-
-void string_list_append(struct string_list *list, char *string)
-{
- ASSERT(list->length <= list->capacity);
- if (list->length == list->capacity) {
- list->capacity = (list->capacity * 2) + 4;
- list->strings = realloc(list->strings,
- sizeof(list->strings[0]) *
- list->capacity);
- if (!list->strings)
- fatal_error("out of memory");
- }
- list->strings[list->length++] = string;
-}
-
-void string_list_destroy(struct string_list *list)
-{
- free(list->strings);
- memset(list, 0, sizeof(*list));
-}
diff --git a/util.h b/util.h
index c4cbe48..dfa10f2 100644
--- a/util.h
+++ b/util.h
@@ -49,16 +49,15 @@
_a > _b ? _a : _b; \
})
+#define roundup(x, y) ({ \
+ __typeof__(y) _y = (y); \
+ (((x) + _y - 1) / _y) * _y; \
+})
+
#define ARRAY_SIZE(A) (sizeof(A) / sizeof((A)[0]))
#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
-/*
- * Round 'v' up to the next 'alignment'-byte aligned boundary.
- * 'alignment' must be a power of 2.
- */
-#define ALIGN(v, alignment) (((v) + ((alignment) - 1)) & ~((alignment) - 1))
-
static inline bool is_power_of_2(unsigned long n)
{
return n != 0 && ((n & (n - 1)) == 0);
@@ -78,12 +77,6 @@
# define le32_to_cpu(v) ((__force u32)(__le32)(v))
# define cpu_to_le64(v) ((__force __le64)(u64)(v))
# define le64_to_cpu(v) ((__force u64)(__le64)(v))
-# define cpu_to_be16(v) ((__force __be16)__builtin_bswap16(v))
-# define be16_to_cpu(v) (__builtin_bswap16((__force u16)(v)))
-# define cpu_to_be32(v) ((__force __be32)__builtin_bswap32(v))
-# define be32_to_cpu(v) (__builtin_bswap32((__force u32)(v)))
-# define cpu_to_be64(v) ((__force __be64)__builtin_bswap64(v))
-# define be64_to_cpu(v) (__builtin_bswap64((__force u64)(v)))
#else
# define cpu_to_le16(v) ((__force __le16)__builtin_bswap16(v))
# define le16_to_cpu(v) (__builtin_bswap16((__force u16)(v)))
@@ -91,12 +84,6 @@
# define le32_to_cpu(v) (__builtin_bswap32((__force u32)(v)))
# define cpu_to_le64(v) ((__force __le64)__builtin_bswap64(v))
# define le64_to_cpu(v) (__builtin_bswap64((__force u64)(v)))
-# define cpu_to_be16(v) ((__force __be16)(u16)(v))
-# define be16_to_cpu(v) ((__force u16)(__be16)(v))
-# define cpu_to_be32(v) ((__force __be32)(u32)(v))
-# define be32_to_cpu(v) ((__force u32)(__be32)(v))
-# define cpu_to_be64(v) ((__force __be64)(u64)(v))
-# define be64_to_cpu(v) ((__force u64)(__be64)(v))
#endif
/* ========== Memory allocation ========== */
@@ -105,7 +92,6 @@
void *xzalloc(size_t size);
void *xmemdup(const void *mem, size_t size);
char *xstrdup(const char *s);
-__printf(1, 2) char *xasprintf(const char *format, ...);
/* ========== Error messages and assertions ========== */
@@ -122,22 +108,13 @@
struct filedes {
int fd;
- bool autodelete; /* unlink when closed? */
char *name; /* filename, for logging or error messages */
- u64 pos; /* lseek() position */
};
bool open_file(struct filedes *file, const char *filename, int flags, int mode);
-bool open_tempfile(struct filedes *file);
bool get_file_size(struct filedes *file, u64 *size_ret);
-bool filedes_seek(struct filedes *file, u64 pos, int whence);
bool full_read(struct filedes *file, void *buf, size_t count);
-bool full_pread(struct filedes *file, void *buf, size_t count, u64 offset);
bool full_write(struct filedes *file, const void *buf, size_t count);
-bool full_pwrite(struct filedes *file, const void *buf, size_t count,
- u64 offset);
-bool copy_file_data(struct filedes *src, struct filedes *dst, u64 length);
-bool write_zeroes(struct filedes *file, u64 length);
bool filedes_close(struct filedes *file);
/* ========== String utilities ========== */
@@ -145,16 +122,4 @@
bool hex2bin(const char *hex, u8 *bin, size_t bin_len);
void bin2hex(const u8 *bin, size_t bin_len, char *hex);
-struct string_list {
- char **strings;
- size_t length;
- size_t capacity;
-};
-
-#define STRING_LIST_INITIALIZER { .strings = NULL, .length = 0, .capacity = 0 }
-#define STRING_LIST(_list) struct string_list _list = STRING_LIST_INITIALIZER
-
-void string_list_append(struct string_list *list, char *string);
-void string_list_destroy(struct string_list *list);
-
#endif /* UTIL_H */
