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import: make verification code generic, in preparation for using it pull-tar

This commit is contained in:
Lennart Poettering 2015-01-21 03:46:01 +01:00
parent 5a3b1abd0e
commit 98c3800184
5 changed files with 270 additions and 224 deletions
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26
src/import/import-job.c
View File

@ -38,22 +38,20 @@ ImportJob* import_job_unref(ImportJob *j) {
else if (j->compressed == IMPORT_JOB_GZIP)
inflateEnd(&j->gzip);
if (j->hash_context)
gcry_md_close(j->hash_context);
if (j->checksum_context)
gcry_md_close(j->checksum_context);
free(j->url);
free(j->etag);
strv_free(j->old_etags);
free(j->payload);
free(j->sha256);
free(j->checksum);
free(j);
return NULL;
}
DEFINE_TRIVIAL_CLEANUP_FUNC(ImportJob*, import_job_unref);
static void import_job_finish(ImportJob *j, int ret) {
assert(j);
@ -124,23 +122,23 @@ void import_job_curl_on_finished(CurlGlue *g, CURL *curl, CURLcode result) {
goto finish;
}
if (j->hash_context) {
if (j->checksum_context) {
uint8_t *k;
k = gcry_md_read(j->hash_context, GCRY_MD_SHA256);
k = gcry_md_read(j->checksum_context, GCRY_MD_SHA256);
if (!k) {
log_error("Failed to get checksum.");
r = -EIO;
goto finish;
}
j->sha256 = hexmem(k, gcry_md_get_algo_dlen(GCRY_MD_SHA256));
if (!j->sha256) {
j->checksum = hexmem(k, gcry_md_get_algo_dlen(GCRY_MD_SHA256));
if (!j->checksum) {
r = log_oom();
goto finish;
}
log_debug("SHA256 of %s is %s.", j->url, j->sha256);
log_debug("SHA256 of %s is %s.", j->url, j->checksum);
}
if (j->disk_fd >= 0 && j->allow_sparse) {
@ -243,8 +241,8 @@ static int import_job_write_compressed(ImportJob *j, void *p, size_t sz) {
return -EFBIG;
}
if (j->hash_context)
gcry_md_write(j->hash_context, p, sz);
if (j->checksum_context)
gcry_md_write(j->checksum_context, p, sz);
switch (j->compressed) {
@ -335,8 +333,8 @@ static int import_job_open_disk(ImportJob *j) {
}
}
if (j->calc_hash) {
if (gcry_md_open(&j->hash_context, GCRY_MD_SHA256, 0) != 0) {
if (j->calc_checksum) {
if (gcry_md_open(&j->checksum_context, GCRY_MD_SHA256, 0) != 0) {
log_error("Failed to initialize hash context.");
return -EIO;
}

8
src/import/import-job.h
View File

@ -96,10 +96,10 @@ struct ImportJob {
bool allow_sparse;
bool calc_hash;
gcry_md_hd_t hash_context;
bool calc_checksum;
gcry_md_hd_t checksum_context;
char *sha256;
char *checksum;
};
int import_job_new(ImportJob **job, const char *url, CurlGlue *glue, void *userdata);
@ -108,3 +108,5 @@ ImportJob* import_job_unref(ImportJob *job);
int import_job_begin(ImportJob *j);
void import_job_curl_on_finished(CurlGlue *g, CURL *curl, CURLcode result);
DEFINE_TRIVIAL_CLEANUP_FUNC(ImportJob*, import_job_unref);

221
src/import/import-raw.c
View File

@ -21,9 +21,7 @@
#include <sys/xattr.h>
#include <linux/fs.h>
#include <sys/prctl.h>
#include <curl/curl.h>
#include <gcrypt.h>
#include "utf8.h"
#include "strv.h"
@ -47,7 +45,7 @@ struct RawImport {
char *image_root;
ImportJob *raw_job;
ImportJob *sha256sums_job;
ImportJob *checksum_job;
ImportJob *signature_job;
RawImportFinished on_finished;
@ -67,7 +65,7 @@ RawImport* raw_import_unref(RawImport *i) {
return NULL;
import_job_unref(i->raw_job);
import_job_unref(i->sha256sums_job);
import_job_unref(i->checksum_job);
import_job_unref(i->signature_job);
curl_glue_unref(i->glue);
@ -251,170 +249,6 @@ static int raw_import_make_local_copy(RawImport *i) {
return 0;
}
static int raw_import_verify_sha256sum(RawImport *i) {
_cleanup_close_pair_ int gpg_pipe[2] = { -1, -1 };
_cleanup_free_ char *fn = NULL;
_cleanup_close_ int sig_file = -1;
const char *p, *line;
char sig_file_path[] = "/tmp/sigXXXXXX";
_cleanup_sigkill_wait_ pid_t pid = 0;
int r;
assert(i);
assert(i->raw_job);
if (!i->sha256sums_job)
return 0;
assert(i->raw_job->state == IMPORT_JOB_DONE);
assert(i->raw_job->sha256);
assert(i->sha256sums_job->state == IMPORT_JOB_DONE);
assert(i->sha256sums_job->payload);
assert(i->sha256sums_job->payload_size > 0);
r = import_url_last_component(i->raw_job->url, &fn);
if (r < 0)
return log_oom();
if (!filename_is_valid(fn)) {
log_error("Cannot verify checksum, could not determine valid server-side file name.");
return -EBADMSG;
}
line = strappenda(i->raw_job->sha256, " *", fn, "\n");
p = memmem(i->sha256sums_job->payload,
i->sha256sums_job->payload_size,
line,
strlen(line));
if (!p || (p != (char*) i->sha256sums_job->payload && p[-1] != '\n')) {
log_error("Checksum did not check out, payload has been tempered with.");
return -EBADMSG;
}
log_info("SHA256 checksum of %s is valid.", i->raw_job->url);
if (!i->signature_job)
return 0;
assert(i->signature_job->state == IMPORT_JOB_DONE);
assert(i->signature_job->payload);
assert(i->signature_job->payload_size > 0);
r = pipe2(gpg_pipe, O_CLOEXEC);
if (r < 0)
return log_error_errno(errno, "Failed to create pipe: %m");
sig_file = mkostemp(sig_file_path, O_RDWR);
if (sig_file < 0)
return log_error_errno(errno, "Failed to create temporary file: %m");
r = loop_write(sig_file, i->signature_job->payload, i->signature_job->payload_size, false);
if (r < 0) {
log_error_errno(r, "Failed to write to temporary file: %m");
goto finish;
}
pid = fork();
if (pid < 0)
return log_error_errno(errno, "Failed to fork off gpg: %m");
if (pid == 0) {
const char *cmd[] = {
"gpg",
"--no-options",
"--no-default-keyring",
"--no-auto-key-locate",
"--no-auto-check-trustdb",
"--batch",
"--trust-model=always",
"--keyring=" VENDOR_KEYRING_PATH,
NULL, /* maybe user keyring */
NULL, /* --verify */
NULL, /* signature file */
NULL, /* dash */
NULL /* trailing NULL */
};
unsigned k = ELEMENTSOF(cmd) - 5;
int null_fd;
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
gpg_pipe[1] = safe_close(gpg_pipe[1]);
if (dup2(gpg_pipe[0], STDIN_FILENO) != STDIN_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (gpg_pipe[0] != STDIN_FILENO)
gpg_pipe[0] = safe_close(gpg_pipe[0]);
null_fd = open("/dev/null", O_WRONLY|O_NOCTTY);
if (null_fd < 0) {
log_error_errno(errno, "Failed to open /dev/null: %m");
_exit(EXIT_FAILURE);
}
if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (null_fd != STDOUT_FILENO)
null_fd = safe_close(null_fd);
/* We add the user keyring only to the command line
* arguments, if it's around since gpg fails
* otherwise. */
if (access(USER_KEYRING_PATH, F_OK) >= 0)
cmd[k++] = "--keyring=" USER_KEYRING_PATH;
cmd[k++] = "--verify";
cmd[k++] = sig_file_path;
cmd[k++] = "-";
cmd[k++] = NULL;
execvp("gpg", (char * const *) cmd);
log_error_errno(errno, "Failed to execute gpg: %m");
_exit(EXIT_FAILURE);
}
gpg_pipe[0] = safe_close(gpg_pipe[0]);
r = loop_write(gpg_pipe[1], i->sha256sums_job->payload, i->sha256sums_job->payload_size, false);
if (r < 0) {
log_error_errno(r, "Failed to write to pipe: %m");
goto finish;
}
gpg_pipe[1] = safe_close(gpg_pipe[1]);
r = wait_for_terminate_and_warn("gpg", pid, true);
pid = 0;
if (r < 0)
goto finish;
if (r > 0) {
log_error("Signature verification failed.");
r = -EBADMSG;
} else {
log_info("Signature verification succeeded.");
r = 0;
}
finish:
if (sig_file >= 0)
unlink(sig_file_path);
return r;
}
static void raw_import_job_on_finished(ImportJob *j) {
RawImport *i;
int r;
@ -424,7 +258,7 @@ static void raw_import_job_on_finished(ImportJob *j) {
i = j->userdata;
if (j->error != 0) {
if (j == i->sha256sums_job)
if (j == i->checksum_job)
log_error_errno(j->error, "Failed to retrieve SHA256 checksum, cannot verify. (Try --verify=no?)");
else if (j == i->signature_job)
log_error_errno(j->error, "Failed to retrieve signature file, cannot verify. (Try --verify=no?)");
@ -442,17 +276,18 @@ static void raw_import_job_on_finished(ImportJob *j) {
*
* We only do something when we got all three files */
if (!IMPORT_JOB_STATE_IS_COMPLETE(i->raw_job))
if (i->raw_job->state != IMPORT_JOB_DONE)
return;
if (i->sha256sums_job && !IMPORT_JOB_STATE_IS_COMPLETE(i->sha256sums_job))
if (i->checksum_job && i->checksum_job->state != IMPORT_JOB_DONE)
return;
if (i->signature_job && !IMPORT_JOB_STATE_IS_COMPLETE(i->signature_job))
if (i->signature_job && i->signature_job->state != IMPORT_JOB_DONE)
return;
if (!i->raw_job->etag_exists) {
/* This is a new download, verify it, and move it into place */
assert(i->raw_job->disk_fd >= 0);
r = raw_import_verify_sha256sum(i);
r = import_verify(i->raw_job, i->checksum_job, i->signature_job);
if (r < 0)
goto finish;
@ -546,50 +381,22 @@ int raw_import_pull(RawImport *i, const char *url, const char *local, bool force
i->raw_job->on_finished = raw_import_job_on_finished;
i->raw_job->on_open_disk = raw_import_job_on_open_disk;
i->raw_job->calc_hash = true;
i->raw_job->calc_checksum = verify != IMPORT_VERIFY_NO;
r = import_find_old_etags(url, i->image_root, DT_REG, ".raw-", ".raw", &i->raw_job->old_etags);
if (r < 0)
return r;
if (verify != IMPORT_VERIFY_NO) {
_cleanup_free_ char *sha256sums_url = NULL;
/* Queue job for the SHA256SUMS file for the image */
r = import_url_change_last_component(url, "SHA256SUMS", &sha256sums_url);
if (r < 0)
return r;
r = import_job_new(&i->sha256sums_job, sha256sums_url, i->glue, i);
if (r < 0)
return r;
i->sha256sums_job->on_finished = raw_import_job_on_finished;
i->sha256sums_job->uncompressed_max = i->sha256sums_job->compressed_max = 1ULL * 1024ULL * 1024ULL;
}
if (verify == IMPORT_VERIFY_SIGNATURE) {
_cleanup_free_ char *sha256sums_sig_url = NULL;
/* Queue job for the SHA256SUMS.gpg file for the image. */
r = import_url_change_last_component(url, "SHA256SUMS.gpg", &sha256sums_sig_url);
if (r < 0)
return r;
r = import_job_new(&i->signature_job, sha256sums_sig_url, i->glue, i);
if (r < 0)
return r;
i->signature_job->on_finished = raw_import_job_on_finished;
i->signature_job->uncompressed_max = i->signature_job->compressed_max = 1ULL * 1024ULL * 1024ULL;
}
r = import_make_verification_jobs(&i->checksum_job, &i->signature_job, verify, url, i->glue, raw_import_job_on_finished, i);
if (r < 0)
return r;
r = import_job_begin(i->raw_job);
if (r < 0)
return r;
if (i->sha256sums_job) {
r = import_job_begin(i->sha256sums_job);
if (i->checksum_job) {
r = import_job_begin(i->checksum_job);
if (r < 0)
return r;
}

234
src/import/import-util.c
View File

@ -19,10 +19,13 @@
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <sys/prctl.h>
#include "util.h"
#include "strv.h"
#include "copy.h"
#include "btrfs-util.h"
#include "import-job.h"
#include "import-util.h"
#define FILENAME_ESCAPE "/.#\"\'"
@ -278,3 +281,234 @@ static const char* const import_verify_table[_IMPORT_VERIFY_MAX] = {
};
DEFINE_STRING_TABLE_LOOKUP(import_verify, ImportVerify);
int import_make_verification_jobs(
ImportJob **ret_checksum_job,
ImportJob **ret_signature_job,
ImportVerify verify,
const char *url,
CurlGlue *glue,
ImportJobFinished on_finished,
void *userdata) {
_cleanup_(import_job_unrefp) ImportJob *checksum_job = NULL, *signature_job = NULL;
int r;
assert(ret_checksum_job);
assert(ret_signature_job);
assert(verify >= 0);
assert(verify < _IMPORT_VERIFY_MAX);
assert(url);
assert(glue);
if (verify != IMPORT_VERIFY_NO) {
_cleanup_free_ char *checksum_url = NULL;
/* Queue job for the SHA256SUMS file for the image */
r = import_url_change_last_component(url, "SHA256SUMS", &checksum_url);
if (r < 0)
return r;
r = import_job_new(&checksum_job, checksum_url, glue, userdata);
if (r < 0)
return r;
checksum_job->on_finished = on_finished;
checksum_job->uncompressed_max = checksum_job->compressed_max = 1ULL * 1024ULL * 1024ULL;
}
if (verify == IMPORT_VERIFY_SIGNATURE) {
_cleanup_free_ char *signature_url = NULL;
/* Queue job for the SHA256SUMS.gpg file for the image. */
r = import_url_change_last_component(url, "SHA256SUMS.gpg", &signature_url);
if (r < 0)
return r;
r = import_job_new(&signature_job, signature_url, glue, userdata);
if (r < 0)
return r;
signature_job->on_finished = on_finished;
signature_job->uncompressed_max = signature_job->compressed_max = 1ULL * 1024ULL * 1024ULL;
}
*ret_checksum_job = checksum_job;
*ret_signature_job = signature_job;
checksum_job = signature_job = NULL;
return 0;
}
int import_verify(
ImportJob *main_job,
ImportJob *checksum_job,
ImportJob *signature_job) {
_cleanup_close_pair_ int gpg_pipe[2] = { -1, -1 };
_cleanup_free_ char *fn = NULL;
_cleanup_close_ int sig_file = -1;
const char *p, *line;
char sig_file_path[] = "/tmp/sigXXXXXX";
_cleanup_sigkill_wait_ pid_t pid = 0;
int r;
assert(main_job);
assert(main_job->state == IMPORT_JOB_DONE);
if (!checksum_job)
return 0;
assert(main_job->calc_checksum);
assert(main_job->checksum);
assert(checksum_job->state == IMPORT_JOB_DONE);
if (!checksum_job->payload || checksum_job->payload_size <= 0) {
log_error("Checksum is empty, cannot verify.");
return -EBADMSG;
}
r = import_url_last_component(main_job->url, &fn);
if (r < 0)
return log_oom();
if (!filename_is_valid(fn)) {
log_error("Cannot verify checksum, could not determine valid server-side file name.");
return -EBADMSG;
}
line = strappenda(main_job->checksum, " *", fn, "\n");
p = memmem(checksum_job->payload,
checksum_job->payload_size,
line,
strlen(line));
if (!p || (p != (char*) checksum_job->payload && p[-1] != '\n')) {
log_error("Checksum did not check out, payload has been tempered with.");
return -EBADMSG;
}
log_info("SHA256 checksum of %s is valid.", main_job->url);
if (!signature_job)
return 0;
assert(signature_job->state == IMPORT_JOB_DONE);
if (!signature_job->payload || signature_job->payload_size <= 0) {
log_error("Signature is empty, cannot verify.");
return -EBADMSG;
}
r = pipe2(gpg_pipe, O_CLOEXEC);
if (r < 0)
return log_error_errno(errno, "Failed to create pipe: %m");
sig_file = mkostemp(sig_file_path, O_RDWR);
if (sig_file < 0)
return log_error_errno(errno, "Failed to create temporary file: %m");
r = loop_write(sig_file, signature_job->payload, signature_job->payload_size, false);
if (r < 0) {
log_error_errno(r, "Failed to write to temporary file: %m");
goto finish;
}
pid = fork();
if (pid < 0)
return log_error_errno(errno, "Failed to fork off gpg: %m");
if (pid == 0) {
const char *cmd[] = {
"gpg",
"--no-options",
"--no-default-keyring",
"--no-auto-key-locate",
"--no-auto-check-trustdb",
"--batch",
"--trust-model=always",
"--keyring=" VENDOR_KEYRING_PATH,
NULL, /* maybe user keyring */
NULL, /* --verify */
NULL, /* signature file */
NULL, /* dash */
NULL /* trailing NULL */
};
unsigned k = ELEMENTSOF(cmd) - 5;
int null_fd;
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
gpg_pipe[1] = safe_close(gpg_pipe[1]);
if (dup2(gpg_pipe[0], STDIN_FILENO) != STDIN_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (gpg_pipe[0] != STDIN_FILENO)
gpg_pipe[0] = safe_close(gpg_pipe[0]);
null_fd = open("/dev/null", O_WRONLY|O_NOCTTY);
if (null_fd < 0) {
log_error_errno(errno, "Failed to open /dev/null: %m");
_exit(EXIT_FAILURE);
}
if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (null_fd != STDOUT_FILENO)
null_fd = safe_close(null_fd);
/* We add the user keyring only to the command line
* arguments, if it's around since gpg fails
* otherwise. */
if (access(USER_KEYRING_PATH, F_OK) >= 0)
cmd[k++] = "--keyring=" USER_KEYRING_PATH;
cmd[k++] = "--verify";
cmd[k++] = sig_file_path;
cmd[k++] = "-";
cmd[k++] = NULL;
execvp("gpg", (char * const *) cmd);
log_error_errno(errno, "Failed to execute gpg: %m");
_exit(EXIT_FAILURE);
}
gpg_pipe[0] = safe_close(gpg_pipe[0]);
r = loop_write(gpg_pipe[1], checksum_job->payload, checksum_job->payload_size, false);
if (r < 0) {
log_error_errno(r, "Failed to write to pipe: %m");
goto finish;
}
gpg_pipe[1] = safe_close(gpg_pipe[1]);
r = wait_for_terminate_and_warn("gpg", pid, true);
pid = 0;
if (r < 0)
goto finish;
if (r > 0) {
log_error("Signature verification failed.");
r = -EBADMSG;
} else {
log_info("Signature verification succeeded.");
r = 0;
}
finish:
if (sig_file >= 0)
unlink(sig_file_path);
return r;
}

5
src/import/import-util.h
View File

@ -23,6 +23,8 @@
#include <stdbool.h>
#include "import-job.h"
typedef enum ImportVerify {
IMPORT_VERIFY_NO,
IMPORT_VERIFY_SUM,
@ -47,3 +49,6 @@ int import_url_change_last_component(const char *url, const char *suffix, char *
const char* import_verify_to_string(ImportVerify v) _const_;
ImportVerify import_verify_from_string(const char *s) _pure_;
int import_make_verification_jobs(ImportJob **ret_checksum_job, ImportJob **ret_signature_job, ImportVerify verify, const char *url, CurlGlue *glue, ImportJobFinished on_finished, void *userdata);
int import_verify(ImportJob *main_job, ImportJob *checksum_job, ImportJob *signature_job);