cgitsb/ui-snapshot.c
Christian Hesse 7ba41963dd snapshot: support tar signature for compressed tar
This adds support for kernel.org style signatures where the uncompressed
tar archive is signed and compressed later. The signature is valid for
all tar* snapshots.

We have a filter which snapshots may be generated and downloaded. This has
to allow tar signatures now even if tar itself is not allowed. To simplify
things we allow all signatures.

Signed-off-by: Christian Hesse <mail@eworm.de>
2018-07-03 20:37:44 +02:00

302 sor
8.0 KiB
C

/* ui-snapshot.c: generate snapshot of a commit
*
* Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
*
* Licensed under GNU General Public License v2
* (see COPYING for full license text)
*/
#include "cgit.h"
#include "ui-snapshot.h"
#include "html.h"
#include "ui-shared.h"
static int write_archive_type(const char *format, const char *hex, const char *prefix)
{
struct argv_array argv = ARGV_ARRAY_INIT;
const char **nargv;
int result;
argv_array_push(&argv, "snapshot");
argv_array_push(&argv, format);
if (prefix) {
struct strbuf buf = STRBUF_INIT;
strbuf_addstr(&buf, prefix);
strbuf_addch(&buf, '/');
argv_array_push(&argv, "--prefix");
argv_array_push(&argv, buf.buf);
strbuf_release(&buf);
}
argv_array_push(&argv, hex);
/*
* Now we need to copy the pointers to arguments into a new
* structure because write_archive will rearrange its arguments
* which may result in duplicated/missing entries causing leaks
* or double-frees in argv_array_clear.
*/
nargv = xmalloc(sizeof(char *) * (argv.argc + 1));
/* argv_array guarantees a trailing NULL entry. */
memcpy(nargv, argv.argv, sizeof(char *) * (argv.argc + 1));
result = write_archive(argv.argc, nargv, NULL, NULL, 0);
argv_array_clear(&argv);
free(nargv);
return result;
}
static int write_tar_archive(const char *hex, const char *prefix)
{
return write_archive_type("--format=tar", hex, prefix);
}
static int write_zip_archive(const char *hex, const char *prefix)
{
return write_archive_type("--format=zip", hex, prefix);
}
static int write_compressed_tar_archive(const char *hex,
const char *prefix,
char *filter_argv[])
{
int rv;
struct cgit_exec_filter f;
cgit_exec_filter_init(&f, filter_argv[0], filter_argv);
cgit_open_filter(&f.base);
rv = write_tar_archive(hex, prefix);
cgit_close_filter(&f.base);
return rv;
}
static int write_tar_gzip_archive(const char *hex, const char *prefix)
{
char *argv[] = { "gzip", "-n", NULL };
return write_compressed_tar_archive(hex, prefix, argv);
}
static int write_tar_bzip2_archive(const char *hex, const char *prefix)
{
char *argv[] = { "bzip2", NULL };
return write_compressed_tar_archive(hex, prefix, argv);
}
static int write_tar_xz_archive(const char *hex, const char *prefix)
{
char *argv[] = { "xz", NULL };
return write_compressed_tar_archive(hex, prefix, argv);
}
const struct cgit_snapshot_format cgit_snapshot_formats[] = {
/* .tar must remain the 0 index */
{ ".tar", "application/x-tar", write_tar_archive },
{ ".tar.gz", "application/x-gzip", write_tar_gzip_archive },
{ ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive },
{ ".tar.xz", "application/x-xz", write_tar_xz_archive },
{ ".zip", "application/x-zip", write_zip_archive },
{ NULL }
};
static struct notes_tree snapshot_sig_notes[ARRAY_SIZE(cgit_snapshot_formats)];
const struct object_id *cgit_snapshot_get_sig(const char *ref,
const struct cgit_snapshot_format *f)
{
struct notes_tree *tree;
struct object_id oid;
if (get_oid(ref, &oid))
return NULL;
tree = &snapshot_sig_notes[f - &cgit_snapshot_formats[0]];
if (!tree->initialized) {
struct strbuf notes_ref = STRBUF_INIT;
strbuf_addf(&notes_ref, "refs/notes/signatures/%s",
f->suffix + 1);
init_notes(tree, notes_ref.buf, combine_notes_ignore, 0);
strbuf_release(&notes_ref);
}
return get_note(tree, &oid);
}
static const struct cgit_snapshot_format *get_format(const char *filename)
{
const struct cgit_snapshot_format *fmt;
for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
if (ends_with(filename, fmt->suffix))
return fmt;
}
return NULL;
}
const unsigned cgit_snapshot_format_bit(const struct cgit_snapshot_format *f)
{
return BIT(f - &cgit_snapshot_formats[0]);
}
static int make_snapshot(const struct cgit_snapshot_format *format,
const char *hex, const char *prefix,
const char *filename)
{
struct object_id oid;
if (get_oid(hex, &oid)) {
cgit_print_error_page(404, "Not found",
"Bad object id: %s", hex);
return 1;
}
if (!lookup_commit_reference(&oid)) {
cgit_print_error_page(400, "Bad request",
"Not a commit reference: %s", hex);
return 1;
}
ctx.page.etag = oid_to_hex(&oid);
ctx.page.mimetype = xstrdup(format->mimetype);
ctx.page.filename = xstrdup(filename);
cgit_print_http_headers();
format->write_func(hex, prefix);
return 0;
}
static int write_sig(const struct cgit_snapshot_format *format,
const char *hex, const char *archive,
const char *filename)
{
const struct object_id *note = cgit_snapshot_get_sig(hex, format);
enum object_type type;
unsigned long size;
char *buf;
if (!note) {
cgit_print_error_page(404, "Not found",
"No signature for %s", archive);
return 0;
}
buf = read_object_file(note, &type, &size);
if (!buf) {
cgit_print_error_page(404, "Not found", "Not found");
return 0;
}
html("X-Content-Type-Options: nosniff\n");
html("Content-Security-Policy: default-src 'none'\n");
ctx.page.etag = oid_to_hex(note);
ctx.page.mimetype = xstrdup("application/pgp-signature");
ctx.page.filename = xstrdup(filename);
cgit_print_http_headers();
html_raw(buf, size);
free(buf);
return 0;
}
/* Try to guess the requested revision from the requested snapshot name.
* First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
* "cgit-0.7.2". If this is a valid commit object name we've got a winner.
* Otherwise, if the snapshot name has a prefix matching the result from
* repo_basename(), we strip the basename and any following '-' and '_'
* characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
* more. If this still isn't a valid commit object name, we check if pre-
* pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
* "v0.7.2") gives us something valid.
*/
static const char *get_ref_from_filename(const struct cgit_repo *repo,
const char *filename,
const struct cgit_snapshot_format *format)
{
const char *reponame;
struct object_id oid;
struct strbuf snapshot = STRBUF_INIT;
int result = 1;
strbuf_addstr(&snapshot, filename);
strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
if (get_oid(snapshot.buf, &oid) == 0)
goto out;
reponame = cgit_snapshot_prefix(repo);
if (starts_with(snapshot.buf, reponame)) {
const char *new_start = snapshot.buf;
new_start += strlen(reponame);
while (new_start && (*new_start == '-' || *new_start == '_'))
new_start++;
strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
}
if (get_oid(snapshot.buf, &oid) == 0)
goto out;
strbuf_insert(&snapshot, 0, "v", 1);
if (get_oid(snapshot.buf, &oid) == 0)
goto out;
strbuf_splice(&snapshot, 0, 1, "V", 1);
if (get_oid(snapshot.buf, &oid) == 0)
goto out;
result = 0;
strbuf_release(&snapshot);
out:
return result ? strbuf_detach(&snapshot, NULL) : NULL;
}
void cgit_print_snapshot(const char *head, const char *hex,
const char *filename, int dwim)
{
const struct cgit_snapshot_format* f;
const char *sig_filename = NULL;
char *adj_filename = NULL;
char *prefix = NULL;
if (!filename) {
cgit_print_error_page(400, "Bad request",
"No snapshot name specified");
return;
}
if (ends_with(filename, ".asc")) {
sig_filename = filename;
/* Strip ".asc" from filename for common format processing */
adj_filename = xstrdup(filename);
adj_filename[strlen(adj_filename) - 4] = '\0';
filename = adj_filename;
}
f = get_format(filename);
if (!f || (!sig_filename && !(ctx.repo->snapshots & cgit_snapshot_format_bit(f)))) {
cgit_print_error_page(400, "Bad request",
"Unsupported snapshot format: %s", filename);
return;
}
if (!hex && dwim) {
hex = get_ref_from_filename(ctx.repo, filename, f);
if (hex == NULL) {
cgit_print_error_page(404, "Not found", "Not found");
return;
}
prefix = xstrdup(filename);
prefix[strlen(filename) - strlen(f->suffix)] = '\0';
}
if (!hex)
hex = head;
if (!prefix)
prefix = xstrdup(cgit_snapshot_prefix(ctx.repo));
if (sig_filename)
write_sig(f, hex, filename, sig_filename);
else
make_snapshot(f, hex, prefix, filename);
free(prefix);
free(adj_filename);
}