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