usign-exec.c

   1 /*
   2  * wrapper functions around the usign executable
   3  * Copyright (C) 2018 Daniel Golle <daniel@makrotopia.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 3
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <stdbool.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18 #include <unistd.h>
  19 #include <sys/wait.h>
  20
  21 #include "usign.h"
  22
  23 int usign_s(const char *msgfile, const char *seckeyfile, const char *sigfile, bool quiet) {
  24         pid_t pid;
  25         int status;
  26         const char *usign_argv[16] = {0};
  27         unsigned int usign_argc = 0;
  28
  29         usign_argv[usign_argc++] = "/usr/bin/usign";
  30         usign_argv[usign_argc++] = "-S";
  31         usign_argv[usign_argc++] = "-m";
  32         usign_argv[usign_argc++] = msgfile;
  33         usign_argv[usign_argc++] = "-s";
  34         usign_argv[usign_argc++] = seckeyfile;
  35         usign_argv[usign_argc++] = "-x";
  36         usign_argv[usign_argc++] = sigfile;
  37
  38         if (quiet)
  39                 usign_argv[usign_argc++] = "-q";
  40
  41         pid = fork();
  42         switch (pid) {
  43         case -1:
  44                 return -1;
  45
  46         case 0:
  47                 if (execv(usign_argv[0], usign_argv))
  48                         return -1;
  49
  50                 break;
  51
  52         default:
  53                 waitpid(pid, &status, 0);
  54                 return WEXITSTATUS(status);
  55         }
  56
  57         return -1;
  58 }
  59
  60 static int usign_f(char *fingerprint, const char *pubkeyfile, const char *seckeyfile, const char *sigfile) {
  61         int fds[2];
  62         pid_t pid;
  63         int status;
  64         const char *usign_argv[16] = {0};
  65         unsigned int usign_argc = 0;
  66
  67         if (pipe(fds))
  68                 return -1;
  69
  70         usign_argv[usign_argc++] = "/usr/bin/usign";
  71         usign_argv[usign_argc++] = "-F";
  72
  73         if (pubkeyfile) {
  74                 usign_argv[usign_argc++] = "-p";
  75                 usign_argv[usign_argc++] = pubkeyfile;
  76         }
  77
  78         if (seckeyfile) {
  79                 usign_argv[usign_argc++] = "-s";
  80                 usign_argv[usign_argc++] = seckeyfile;
  81         }
  82
  83         if (sigfile) {
  84                 usign_argv[usign_argc++] = "-x";
  85                 usign_argv[usign_argc++] = sigfile;
  86         }
  87
  88         pid = fork();
  89         switch (pid) {
  90         case -1:
  91                 return -1;
  92
  93         case 0:
  94                 dup2(fds[1], 1);
  95
  96                 close(0);
  97                 close(2);
  98                 close(fds[0]);
  99                 close(fds[1]);
 100
 101                 if (execv(usign_argv[0], usign_argv))
 102                         return -1;
 103
 104                 break;
 105
 106         default:
 107                 waitpid(pid, &status, 0);
 108                 if (fingerprint && !WEXITSTATUS(status)) {
 109                         memset(fingerprint, 0, 16);
 110                         read(fds[0], fingerprint, 16);
 111                         fingerprint[16] = '\0';
 112                 }
 113                 close(fds[0]);
 114                 close(fds[1]);
 115                 return WEXITSTATUS(status);
 116         }
 117
 118         return -1;
 119 }
 120
 121 int usign_f_pubkey(char *fingerprint, const char *pubkeyfile) {
 122         return usign_f(fingerprint, pubkeyfile, NULL, NULL);
 123 }
 124
 125 int usign_f_seckey(char *fingerprint, const char *seckeyfile) {
 126         return usign_f(fingerprint, NULL, seckeyfile, NULL);
 127 }
 128
 129 int usign_f_sig(char *fingerprint, const char *sigfile) {
 130         return usign_f(fingerprint, NULL, NULL, sigfile);
 131 }
 132
 133 int _usign_key_is_revoked(const char *fingerprint, const char *pubkeydir) {
 134         char tml[64] = {0};
 135         char rfname[256] = {0};
 136
 137         snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
 138         if (readlink(rfname, tml, sizeof(tml)) > 0 &&
 139             !strcmp(tml, ".revoked.")) {
 140                 return true;
 141         };
 142
 143         return false;
 144 }
 145
 146 int usign_v(const char *msgfile, const char *pubkeyfile,
 147             const char *pubkeydir, const char *sigfile, bool quiet) {
 148         pid_t pid;
 149         int status;
 150         const char *usign_argv[16] = {0};
 151         unsigned int usign_argc = 0;
 152         char fingerprint[17];
 153
 154         if (usign_f_sig(fingerprint, sigfile))
 155                 return 1;
 156
 157         if (pubkeydir && _usign_key_is_revoked(fingerprint, pubkeydir))
 158                 return 1;
 159
 160         usign_argv[usign_argc++] = "/usr/bin/usign";
 161         usign_argv[usign_argc++] = "-V";
 162         usign_argv[usign_argc++] = "-m";
 163         usign_argv[usign_argc++] = msgfile;
 164
 165         if (quiet)
 166                 usign_argv[usign_argc++] = "-q";
 167
 168         if (pubkeyfile) {
 169                 usign_argv[usign_argc++] = "-p";
 170                 usign_argv[usign_argc++] = pubkeyfile;
 171         }
 172
 173         if (pubkeydir) {
 174                 usign_argv[usign_argc++] = "-P";
 175                 usign_argv[usign_argc++] = pubkeydir;
 176         }
 177
 178         if (sigfile) {
 179                 usign_argv[usign_argc++] = "-x";
 180                 usign_argv[usign_argc++] = sigfile;
 181         }
 182
 183         pid = fork();
 184         switch (pid) {
 185         case -1:
 186                 return -1;
 187
 188         case 0:
 189                 if (execv(usign_argv[0], usign_argv))
 190                         return -1;
 191
 192                 break;
 193
 194         default:
 195                 waitpid(pid, &status, 0);
 196                 return WEXITSTATUS(status);
 197         }
 198
 199         return -1;
 200 }