receive-pack: detect aliased updates which can occur with symrefs
[git] / builtin-verify-tag.c
1 /*
2  * Builtin "git verify-tag"
3  *
4  * Copyright (c) 2007 Carlos Rica <jasampler@gmail.com>
5  *
6  * Based on git-verify-tag.sh
7  */
8 #include "cache.h"
9 #include "builtin.h"
10 #include "tag.h"
11 #include "run-command.h"
12 #include <signal.h>
13 #include "parse-options.h"
14
15 static const char * const verify_tag_usage[] = {
16                 "git verify-tag [-v|--verbose] <tag>...",
17                 NULL
18 };
19
20 #define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
21
22 static int run_gpg_verify(const char *buf, unsigned long size, int verbose)
23 {
24         struct child_process gpg;
25         const char *args_gpg[] = {"gpg", "--verify", "FILE", "-", NULL};
26         char path[PATH_MAX], *eol;
27         size_t len;
28         int fd, ret;
29
30         fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX");
31         if (fd < 0)
32                 return error("could not create temporary file '%s': %s",
33                                                 path, strerror(errno));
34         if (write_in_full(fd, buf, size) < 0)
35                 return error("failed writing temporary file '%s': %s",
36                                                 path, strerror(errno));
37         close(fd);
38
39         /* find the length without signature */
40         len = 0;
41         while (len < size && prefixcmp(buf + len, PGP_SIGNATURE)) {
42                 eol = memchr(buf + len, '\n', size - len);
43                 len += eol ? eol - (buf + len) + 1 : size - len;
44         }
45         if (verbose)
46                 write_in_full(1, buf, len);
47
48         memset(&gpg, 0, sizeof(gpg));
49         gpg.argv = args_gpg;
50         gpg.in = -1;
51         args_gpg[2] = path;
52         if (start_command(&gpg)) {
53                 unlink(path);
54                 return error("could not run gpg.");
55         }
56
57         write_in_full(gpg.in, buf, len);
58         close(gpg.in);
59         ret = finish_command(&gpg);
60
61         unlink_or_warn(path);
62
63         return ret;
64 }
65
66 static int verify_tag(const char *name, int verbose)
67 {
68         enum object_type type;
69         unsigned char sha1[20];
70         char *buf;
71         unsigned long size;
72         int ret;
73
74         if (get_sha1(name, sha1))
75                 return error("tag '%s' not found.", name);
76
77         type = sha1_object_info(sha1, NULL);
78         if (type != OBJ_TAG)
79                 return error("%s: cannot verify a non-tag object of type %s.",
80                                 name, typename(type));
81
82         buf = read_sha1_file(sha1, &type, &size);
83         if (!buf)
84                 return error("%s: unable to read file.", name);
85
86         ret = run_gpg_verify(buf, size, verbose);
87
88         free(buf);
89         return ret;
90 }
91
92 int cmd_verify_tag(int argc, const char **argv, const char *prefix)
93 {
94         int i = 1, verbose = 0, had_error = 0;
95         const struct option verify_tag_options[] = {
96                 OPT__VERBOSE(&verbose),
97                 OPT_END()
98         };
99
100         git_config(git_default_config, NULL);
101
102         argc = parse_options(argc, argv, prefix, verify_tag_options,
103                              verify_tag_usage, PARSE_OPT_KEEP_ARGV0);
104         if (argc <= i)
105                 usage_with_options(verify_tag_usage, verify_tag_options);
106
107         /* sometimes the program was terminated because this signal
108          * was received in the process of writing the gpg input: */
109         signal(SIGPIPE, SIG_IGN);
110         while (i < argc)
111                 if (verify_tag(argv[i++], verbose))
112                         had_error = 1;
113         return had_error;
114 }