From: Lennart Poettering Date: Tue, 20 Jan 2015 14:06:34 +0000 (+0100) Subject: import: add a simple scheme for validating the SHA256 sums of downloaded raw files X-Git-Tag: v219~416 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=85dbc41dc67ff49fd8a843dbac5b8b5cb0b61155 import: add a simple scheme for validating the SHA256 sums of downloaded raw files --- diff --git a/Makefile.am b/Makefile.am index f165042cb..b6a4e3e4e 100644 --- a/Makefile.am +++ b/Makefile.am @@ -5238,6 +5238,9 @@ lib_LTLIBRARIES += \ libnss_mymachines.la if HAVE_LIBCURL +if HAVE_XZ +if HAVE_ZLIB +if HAVE_GCRYPT bin_PROGRAMS += \ systemd-import @@ -5265,7 +5268,8 @@ systemd_import_CFLAGS = \ $(AM_CFLAGS) \ $(LIBCURL_CFLAGS) \ $(XZ_CFLAGS) \ - $(ZLIB_CFLAGS) + $(ZLIB_CFLAGS) \ + $(GCRYPT_CFLAGS) systemd_import_LDADD = \ libsystemd-internal.la \ @@ -5273,11 +5277,9 @@ systemd_import_LDADD = \ libsystemd-shared.la \ $(LIBCURL_LIBS) \ $(XZ_LIBS) \ - $(ZLIB_LIBS) - -endif + $(ZLIB_LIBS) \ + $(GCRYPT_LIBS) -if HAVE_ZLIB manual_tests += \ test-qcow2 @@ -5296,6 +5298,9 @@ test_qcow2_LDADD = \ libsystemd-shared.la \ $(ZLIB_LIBS) endif +endif +endif +endif endif diff --git a/src/import/import-job.c b/src/import/import-job.c index 37f8ef76e..6de32686c 100644 --- a/src/import/import-job.c +++ b/src/import/import-job.c @@ -38,10 +38,14 @@ 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); + free(j->url); free(j->etag); strv_free(j->old_etags); free(j->payload); + free(j->sha256); free(j); @@ -94,6 +98,7 @@ void import_job_curl_on_finished(CurlGlue *g, CURL *curl, CURLcode result) { goto finish; } else if (status == 304) { log_info("Image already downloaded. Skipping download."); + j->etag_exists = true; r = 0; goto finish; } else if (status >= 300) { @@ -119,6 +124,25 @@ void import_job_curl_on_finished(CurlGlue *g, CURL *curl, CURLcode result) { goto finish; } + if (j->hash_context) { + uint8_t *k; + + k = gcry_md_read(j->hash_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) { + r = log_oom(); + goto finish; + } + + log_debug("SHA256 of %s is %s.", j->url, j->sha256); + } + if (j->disk_fd >= 0 && j->allow_sparse) { /* Make sure the file size is right, in case the file was * sparse and we just seeked for the last part */ @@ -151,14 +175,12 @@ finish: import_job_finish(j, r); } - static int import_job_write_uncompressed(ImportJob *j, void *p, size_t sz) { ssize_t n; assert(j); assert(p); assert(sz > 0); - assert(j->disk_fd >= 0); if (j->written_uncompressed + sz < j->written_uncompressed) { log_error("File too large, overflow"); @@ -204,7 +226,6 @@ static int import_job_write_compressed(ImportJob *j, void *p, size_t sz) { assert(j); assert(p); assert(sz > 0); - assert(j->disk_fd >= 0); if (j->written_compressed + sz < j->written_compressed) { log_error("File too large, overflow"); @@ -222,6 +243,9 @@ 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); + switch (j->compressed) { case IMPORT_JOB_UNCOMPRESSED: @@ -311,6 +335,13 @@ static int import_job_open_disk(ImportJob *j) { } } + if (j->calc_hash) { + if (gcry_md_open(&j->hash_context, GCRY_MD_SHA256, 0) != 0) { + log_error("Failed to initialize hash context."); + return -EIO; + } + } + return 0; } @@ -459,6 +490,7 @@ static size_t import_job_header_callback(void *contents, size_t size, size_t nme if (strv_contains(j->old_etags, j->etag)) { log_info("Image already downloaded. Skipping download."); + j->etag_exists = true; import_job_finish(j, 0); return sz; } diff --git a/src/import/import-job.h b/src/import/import-job.h index 843daa217..9ccaaf2c0 100644 --- a/src/import/import-job.h +++ b/src/import/import-job.h @@ -23,6 +23,7 @@ #include #include +#include #include "macro.h" #include "curl-util.h" @@ -42,6 +43,8 @@ typedef enum ImportJobState { _IMPORT_JOB_STATE_INVALID = -1, } ImportJobState; +#define IMPORT_JOB_STATE_IS_COMPLETE(j) (IN_SET((j)->state, IMPORT_JOB_DONE, IMPORT_JOB_FAILED)) + typedef enum ImportJobCompression { IMPORT_JOB_UNCOMPRESSED, IMPORT_JOB_XZ, @@ -66,6 +69,7 @@ struct ImportJob { char *etag; char **old_etags; + bool etag_exists; uint64_t content_length; uint64_t written_compressed; @@ -91,6 +95,11 @@ struct ImportJob { usec_t last_status_usec; bool allow_sparse; + + bool calc_hash; + gcry_md_hd_t hash_context; + + char *sha256; }; int import_job_new(ImportJob **job, const char *url, CurlGlue *glue, void *userdata); diff --git a/src/import/import-raw.c b/src/import/import-raw.c index 635779c1b..8ca10919a 100644 --- a/src/import/import-raw.c +++ b/src/import/import-raw.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "utf8.h" #include "strv.h" @@ -45,6 +46,7 @@ struct RawImport { char *image_root; ImportJob *raw_job; + ImportJob *sha256sums_job; RawImportFinished on_finished; void *userdata; @@ -176,10 +178,11 @@ static int raw_import_make_local_copy(RawImport *i) { if (!i->local) return 0; - if (i->raw_job->disk_fd >= 0) { - if (lseek(i->raw_job->disk_fd, SEEK_SET, 0) == (off_t) -1) - return log_error_errno(errno, "Failed to seek to beginning of vendor image: %m"); - } else { + if (i->raw_job->etag_exists) { + /* We have downloaded this one previously, reopen it */ + + assert(i->raw_job->disk_fd < 0); + if (!i->final_path) { r = import_make_path(i->raw_job->url, i->raw_job->etag, i->image_root, ".raw-", ".raw", &i->final_path); if (r < 0) @@ -189,6 +192,13 @@ static int raw_import_make_local_copy(RawImport *i) { i->raw_job->disk_fd = open(i->final_path, O_RDONLY|O_NOCTTY|O_CLOEXEC); if (i->raw_job->disk_fd < 0) return log_error_errno(errno, "Failed to open vendor image: %m"); + } else { + /* We freshly downloaded the image, use it */ + + assert(i->raw_job->disk_fd >= 0); + + if (lseek(i->raw_job->disk_fd, SEEK_SET, 0) == (off_t) -1) + return log_error_errno(errno, "Failed to seek to beginning of vendor image: %m"); } p = strappenda(i->image_root, "/", i->local, ".raw"); @@ -235,7 +245,91 @@ static int raw_import_make_local_copy(RawImport *i) { return 0; } -static void raw_import_job_on_finished(ImportJob *j) { +static int raw_import_verify_sha256sum(RawImport *i) { + _cleanup_free_ char *fn = NULL; + const char *p, *line; + int r; + + assert(i); + + assert(i->raw_job); + assert(i->raw_job->sha256); + + assert(i->sha256sums_job); + 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); + + return 0; +} + +static int raw_import_finalize(RawImport *i) { + int r; + + assert(i); + + if (!IMPORT_JOB_STATE_IS_COMPLETE(i->raw_job) || + !IMPORT_JOB_STATE_IS_COMPLETE(i->sha256sums_job)) + return 0; + + if (!i->raw_job->etag_exists) { + assert(i->temp_path); + assert(i->final_path); + assert(i->raw_job->disk_fd >= 0); + + r = raw_import_verify_sha256sum(i); + if (r < 0) + return r; + + r = rename(i->temp_path, i->final_path); + if (r < 0) + return log_error_errno(errno, "Failed to move RAW file into place: %m"); + + free(i->temp_path); + i->temp_path = NULL; + } + + r = raw_import_make_local_copy(i); + if (r < 0) + return r; + + i->raw_job->disk_fd = safe_close(i->raw_job->disk_fd); + + return 1; +} + +static void raw_import_invoke_finished(RawImport *i, int r) { + assert(i); + + if (i->on_finished) + i->on_finished(i, r, i->userdata); + else + sd_event_exit(i->event, r); +} + +static void raw_import_raw_job_on_finished(ImportJob *j) { RawImport *i; int r; @@ -250,9 +344,12 @@ static void raw_import_job_on_finished(ImportJob *j) { /* This is invoked if either the download completed * successfully, or the download was skipped because we - * already have the etag. */ + * already have the etag. In this case ->etag_exists is + * true. */ + + if (!j->etag_exists) { + assert(j->disk_fd >= 0); - if (j->disk_fd >= 0) { r = raw_import_maybe_convert_qcow2(i); if (r < 0) goto finish; @@ -260,33 +357,45 @@ static void raw_import_job_on_finished(ImportJob *j) { r = import_make_read_only_fd(j->disk_fd); if (r < 0) goto finish; + } - r = rename(i->temp_path, i->final_path); - if (r < 0) { - r = log_error_errno(errno, "Failed to move RAW file into place: %m"); - goto finish; - } + r = raw_import_finalize(i); + if (r < 0) + goto finish; + if (r == 0) + return; - free(i->temp_path); - i->temp_path = NULL; + r = 0; + +finish: + raw_import_invoke_finished(i, r); +} + +static void raw_import_sha256sums_job_on_finished(ImportJob *j) { + RawImport *i; + int r; + + assert(j); + assert(j->userdata); + + i = j->userdata; + if (j->error != 0) { + r = j->error; + goto finish; } - r = raw_import_make_local_copy(i); + r = raw_import_finalize(i); if (r < 0) goto finish; - - j->disk_fd = safe_close(j->disk_fd); + if (r == 0) + return; r = 0; - finish: - if (i->on_finished) - i->on_finished(i, r, i->userdata); - else - sd_event_exit(i->event, r); + raw_import_invoke_finished(i, r); } -static int raw_import_job_on_open_disk(ImportJob *j) { +static int raw_import_raw_job_on_open_disk(ImportJob *j) { RawImport *i; int r; @@ -317,6 +426,7 @@ static int raw_import_job_on_open_disk(ImportJob *j) { } int raw_import_pull(RawImport *i, const char *url, const char *local, bool force_local) { + _cleanup_free_ char *sha256sums_url = NULL; int r; assert(i); @@ -333,19 +443,40 @@ int raw_import_pull(RawImport *i, const char *url, const char *local, bool force r = free_and_strdup(&i->local, local); if (r < 0) return r; - i->force_local = force_local; + /* Queue job for the image itself */ r = import_job_new(&i->raw_job, url, i->glue, i); if (r < 0) return r; - 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->on_finished = raw_import_raw_job_on_finished; + i->raw_job->on_open_disk = raw_import_raw_job_on_open_disk; + i->raw_job->calc_hash = true; r = import_find_old_etags(url, i->image_root, DT_REG, ".raw-", ".raw", &i->raw_job->old_etags); if (r < 0) return r; - return import_job_begin(i->raw_job); + /* 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_sha256sums_job_on_finished; + i->sha256sums_job->uncompressed_max = i->sha256sums_job->compressed_max = 1ULL * 1024ULL * 1024ULL; + + r = import_job_begin(i->raw_job); + if (r < 0) + return r; + + r = import_job_begin(i->sha256sums_job); + if (r < 0) + return r; + + return 0; } diff --git a/src/import/import-util.c b/src/import/import-util.c index 341a566e3..1212025d4 100644 --- a/src/import/import-util.c +++ b/src/import/import-util.c @@ -218,3 +218,55 @@ int import_make_path(const char *url, const char *etag, const char *image_root, *ret = path; return 0; } + +int import_url_last_component(const char *url, char **ret) { + const char *e, *p; + char *s; + + e = strchrnul(url, '?'); + + while (e > url && e[-1] == '/') + e--; + + p = e; + while (p > url && p[-1] != '/') + p--; + + if (e <= p) + return -EINVAL; + + s = strndup(p, e - p); + if (!s) + return -ENOMEM; + + *ret = s; + return 0; +} + + +int import_url_change_last_component(const char *url, const char *suffix, char **ret) { + const char *e; + char *s; + + assert(url); + assert(ret); + + e = strchrnul(url, '?'); + + while (e > url && e[-1] == '/') + e--; + + while (e > url && e[-1] != '/') + e--; + + if (e <= url) + return -EINVAL; + + s = new(char, (e - url) + strlen(suffix) + 1); + if (!s) + return -ENOMEM; + + strcpy(mempcpy(s, url, e - url), suffix); + *ret = s; + return 0; +} diff --git a/src/import/import-util.h b/src/import/import-util.h index a930ea48a..a8a5ca569 100644 --- a/src/import/import-util.h +++ b/src/import/import-util.h @@ -33,3 +33,6 @@ int import_make_read_only_fd(int fd); int import_make_read_only(const char *path); int import_make_path(const char *url, const char *etag, const char *image_root, const char *prefix, const char *suffix, char **ret); + +int import_url_last_component(const char *url, char **ret); +int import_url_change_last_component(const char *url, const char *suffix, char **ret); diff --git a/src/import/import.c b/src/import/import.c index 861a44858..3362f4a9e 100644 --- a/src/import/import.c +++ b/src/import/import.c @@ -29,6 +29,7 @@ #include "import-tar.h" #include "import-raw.h" #include "import-dkr.h" +#include "import-util.h" static bool arg_force = false; static const char *arg_image_root = "/var/lib/machines"; @@ -47,30 +48,6 @@ static void on_tar_finished(TarImport *import, int error, void *userdata) { sd_event_exit(event, error); } -static int url_final_component(const char *url, char **ret) { - const char *e, *p; - char *s; - - e = strchrnul(url, '?'); - - while (e > url && e[-1] == '/') - e--; - - p = e; - while (p > url && p[-1] != '/') - p--; - - if (e <= p) - return -EINVAL; - - s = strndup(p, e - p); - if (!s) - return -ENOMEM; - - *ret = s; - return 0; -} - static int strip_tar_suffixes(const char *name, char **ret) { const char *e; char *s; @@ -112,7 +89,7 @@ static int pull_tar(int argc, char *argv[], void *userdata) { if (argc >= 3) local = argv[2]; else { - r = url_final_component(url, &l); + r = import_url_last_component(url, &l); if (r < 0) return log_error_errno(r, "Failed get final component of URL: %m"); @@ -238,7 +215,7 @@ static int pull_raw(int argc, char *argv[], void *userdata) { if (argc >= 3) local = argv[2]; else { - r = url_final_component(url, &l); + r = import_url_last_component(url, &l); if (r < 0) return log_error_errno(r, "Failed get final component of URL: %m");