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snapshot: support archive signatures
[ps-cgit] / ui-snapshot.c
1 /* ui-snapshot.c: generate snapshot of a commit
2  *
3  * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
4  *
5  * Licensed under GNU General Public License v2
6  *   (see COPYING for full license text)
7  */
8
9 #include "cgit.h"
10 #include "ui-snapshot.h"
11 #include "html.h"
12 #include "ui-shared.h"
13
14 static int write_archive_type(const char *format, const char *hex, const char *prefix)
15 {
16         struct argv_array argv = ARGV_ARRAY_INIT;
17         const char **nargv;
18         int result;
19         argv_array_push(&argv, "snapshot");
20         argv_array_push(&argv, format);
21         if (prefix) {
22                 struct strbuf buf = STRBUF_INIT;
23                 strbuf_addstr(&buf, prefix);
24                 strbuf_addch(&buf, '/');
25                 argv_array_push(&argv, "--prefix");
26                 argv_array_push(&argv, buf.buf);
27                 strbuf_release(&buf);
28         }
29         argv_array_push(&argv, hex);
30         /*
31          * Now we need to copy the pointers to arguments into a new
32          * structure because write_archive will rearrange its arguments
33          * which may result in duplicated/missing entries causing leaks
34          * or double-frees in argv_array_clear.
35          */
36         nargv = xmalloc(sizeof(char *) * (argv.argc + 1));
37         /* argv_array guarantees a trailing NULL entry. */
38         memcpy(nargv, argv.argv, sizeof(char *) * (argv.argc + 1));
39
40         result = write_archive(argv.argc, nargv, NULL, NULL, 0);
41         argv_array_clear(&argv);
42         free(nargv);
43         return result;
44 }
45
46 static int write_tar_archive(const char *hex, const char *prefix)
47 {
48         return write_archive_type("--format=tar", hex, prefix);
49 }
50
51 static int write_zip_archive(const char *hex, const char *prefix)
52 {
53         return write_archive_type("--format=zip", hex, prefix);
54 }
55
56 static int write_compressed_tar_archive(const char *hex,
57                                         const char *prefix,
58                                         char *filter_argv[])
59 {
60         int rv;
61         struct cgit_exec_filter f;
62         cgit_exec_filter_init(&f, filter_argv[0], filter_argv);
63
64         cgit_open_filter(&f.base);
65         rv = write_tar_archive(hex, prefix);
66         cgit_close_filter(&f.base);
67         return rv;
68 }
69
70 static int write_tar_gzip_archive(const char *hex, const char *prefix)
71 {
72         char *argv[] = { "gzip", "-n", NULL };
73         return write_compressed_tar_archive(hex, prefix, argv);
74 }
75
76 static int write_tar_bzip2_archive(const char *hex, const char *prefix)
77 {
78         char *argv[] = { "bzip2", NULL };
79         return write_compressed_tar_archive(hex, prefix, argv);
80 }
81
82 static int write_tar_xz_archive(const char *hex, const char *prefix)
83 {
84         char *argv[] = { "xz", NULL };
85         return write_compressed_tar_archive(hex, prefix, argv);
86 }
87
88 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
89         { ".zip", "application/x-zip", write_zip_archive, 0x01 },
90         { ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
91         { ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
92         { ".tar", "application/x-tar", write_tar_archive, 0x08 },
93         { ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
94         { NULL }
95 };
96
97 static struct notes_tree snapshot_sig_notes[ARRAY_SIZE(cgit_snapshot_formats)];
98
99 const struct object_id *cgit_snapshot_get_sig(const char *ref,
100                                               const struct cgit_snapshot_format *f)
101 {
102         struct notes_tree *tree;
103         struct object_id oid;
104
105         if (get_oid(ref, &oid))
106                 return NULL;
107
108         tree = &snapshot_sig_notes[f - &cgit_snapshot_formats[0]];
109         if (!tree->initialized) {
110                 struct strbuf notes_ref = STRBUF_INIT;
111
112                 strbuf_addf(&notes_ref, "refs/notes/signatures/%s",
113                             f->suffix + 1);
114
115                 init_notes(tree, notes_ref.buf, combine_notes_ignore, 0);
116                 strbuf_release(&notes_ref);
117         }
118
119         return get_note(tree, &oid);
120 }
121
122 static const struct cgit_snapshot_format *get_format(const char *filename)
123 {
124         const struct cgit_snapshot_format *fmt;
125
126         for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
127                 if (ends_with(filename, fmt->suffix))
128                         return fmt;
129         }
130         return NULL;
131 }
132
133 static int make_snapshot(const struct cgit_snapshot_format *format,
134                          const char *hex, const char *prefix,
135                          const char *filename)
136 {
137         struct object_id oid;
138
139         if (get_oid(hex, &oid)) {
140                 cgit_print_error_page(404, "Not found",
141                                 "Bad object id: %s", hex);
142                 return 1;
143         }
144         if (!lookup_commit_reference(&oid)) {
145                 cgit_print_error_page(400, "Bad request",
146                                 "Not a commit reference: %s", hex);
147                 return 1;
148         }
149         ctx.page.etag = oid_to_hex(&oid);
150         ctx.page.mimetype = xstrdup(format->mimetype);
151         ctx.page.filename = xstrdup(filename);
152         cgit_print_http_headers();
153         format->write_func(hex, prefix);
154         return 0;
155 }
156
157 static int write_sig(const struct cgit_snapshot_format *format,
158                      const char *hex, const char *archive,
159                      const char *filename)
160 {
161         const struct object_id *note = cgit_snapshot_get_sig(hex, format);
162         enum object_type type;
163         unsigned long size;
164         char *buf;
165
166         if (!note) {
167                 cgit_print_error_page(404, "Not found",
168                                 "No signature for %s", archive);
169                 return 0;
170         }
171
172         buf = read_sha1_file(note->hash, &type, &size);
173         if (!buf) {
174                 cgit_print_error_page(404, "Not found", "Not found");
175                 return 0;
176         }
177
178         html("X-Content-Type-Options: nosniff\n");
179         html("Content-Security-Policy: default-src 'none'\n");
180         ctx.page.etag = oid_to_hex(note);
181         ctx.page.mimetype = xstrdup("application/pgp-signature");
182         ctx.page.filename = xstrdup(filename);
183         cgit_print_http_headers();
184
185         html_raw(buf, size);
186         free(buf);
187         return 0;
188 }
189
190 /* Try to guess the requested revision from the requested snapshot name.
191  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
192  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
193  * Otherwise, if the snapshot name has a prefix matching the result from
194  * repo_basename(), we strip the basename and any following '-' and '_'
195  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
196  * more. If this still isn't a valid commit object name, we check if pre-
197  * pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
198  * "v0.7.2") gives us something valid.
199  */
200 static const char *get_ref_from_filename(const struct cgit_repo *repo,
201                                          const char *filename,
202                                          const struct cgit_snapshot_format *format)
203 {
204         const char *reponame;
205         struct object_id oid;
206         struct strbuf snapshot = STRBUF_INIT;
207         int result = 1;
208
209         strbuf_addstr(&snapshot, filename);
210         strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
211
212         if (get_oid(snapshot.buf, &oid) == 0)
213                 goto out;
214
215         reponame = cgit_snapshot_prefix(repo);
216         if (starts_with(snapshot.buf, reponame)) {
217                 const char *new_start = snapshot.buf;
218                 new_start += strlen(reponame);
219                 while (new_start && (*new_start == '-' || *new_start == '_'))
220                         new_start++;
221                 strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
222         }
223
224         if (get_oid(snapshot.buf, &oid) == 0)
225                 goto out;
226
227         strbuf_insert(&snapshot, 0, "v", 1);
228         if (get_oid(snapshot.buf, &oid) == 0)
229                 goto out;
230
231         strbuf_splice(&snapshot, 0, 1, "V", 1);
232         if (get_oid(snapshot.buf, &oid) == 0)
233                 goto out;
234
235         result = 0;
236         strbuf_release(&snapshot);
237
238 out:
239         return result ? strbuf_detach(&snapshot, NULL) : NULL;
240 }
241
242 void cgit_print_snapshot(const char *head, const char *hex,
243                          const char *filename, int dwim)
244 {
245         const struct cgit_snapshot_format* f;
246         const char *sig_filename = NULL;
247         char *adj_filename = NULL;
248         char *prefix = NULL;
249
250         if (!filename) {
251                 cgit_print_error_page(400, "Bad request",
252                                 "No snapshot name specified");
253                 return;
254         }
255
256         if (ends_with(filename, ".asc")) {
257                 sig_filename = filename;
258
259                 /* Strip ".asc" from filename for common format processing */
260                 adj_filename = xstrdup(filename);
261                 adj_filename[strlen(adj_filename) - 4] = '\0';
262                 filename = adj_filename;
263         }
264
265         f = get_format(filename);
266         if (!f || !(ctx.repo->snapshots & f->bit)) {
267                 cgit_print_error_page(400, "Bad request",
268                                 "Unsupported snapshot format: %s", filename);
269                 return;
270         }
271
272         if (!hex && dwim) {
273                 hex = get_ref_from_filename(ctx.repo, filename, f);
274                 if (hex == NULL) {
275                         cgit_print_error_page(404, "Not found", "Not found");
276                         return;
277                 }
278                 prefix = xstrdup(filename);
279                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
280         }
281
282         if (!hex)
283                 hex = head;
284
285         if (!prefix)
286                 prefix = xstrdup(cgit_snapshot_prefix(ctx.repo));
287
288         if (sig_filename)
289                 write_sig(f, hex, filename, sig_filename);
290         else
291                 make_snapshot(f, hex, prefix, filename);
292
293         free(prefix);
294         free(adj_filename);
295 }