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, "print tag contents"),
  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 }