src/signer_chain.cc

   1 /*
   2     Copyright (C) 2013 Carl Hetherington <cth@carlh.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   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     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #include <fstream>
  21 #include <sstream>
  22 #include <boost/filesystem.hpp>
  23 #include <boost/algorithm/string.hpp>
  24 #include <openssl/sha.h>
  25 #include <openssl/bio.h>
  26 #include <openssl/evp.h>
  27 #include "KM_util.h"
  28 #include "signer_chain.h"
  29 #include "exceptions.h"
  30 #include "util.h"
  31
  32 using std::string;
  33 using std::ofstream;
  34 using std::ifstream;
  35 using std::stringstream;
  36 using std::cout;
  37
  38 static void command (string cmd)
  39 {
  40 #ifdef LIBDCP_WINDOWS
  41         /* We need to use CreateProcessW on Windows so that the UTF-8/16 mess
  42            is handled correctly.
  43         */
  44         int const wn = MultiByteToWideChar (CP_UTF8, 0, cmd.c_str(), -1, 0, 0);
  45         wchar_t* buffer = new wchar_t[wn];
  46         if (MultiByteToWideChar (CP_UTF8, 0, cmd.c_str(), -1, buffer, wn) == 0) {
  47                 delete[] buffer;
  48                 return;
  49         }
  50
  51         int code = 1;
  52
  53         STARTUPINFOW startup_info;
  54         memset (&startup_info, 0, sizeof (startup_info));
  55         startup_info.cb = sizeof (startup_info);
  56         PROCESS_INFORMATION process_info;
  57         if (CreateProcessW (0, buffer, 0, 0, FALSE, CREATE_NO_WINDOW, 0, 0, &startup_info, &process_info)) {
  58                 WaitForSingleObject (process_info.hProcess, INFINITE);
  59                 CloseHandle (process_info.hProcess);
  60                 CloseHandle (process_info.hThread);
  61                 DWORD c;
  62                 GetExitCodeProcess (process_info.hProcess, &c);
  63                 code = c;
  64         }
  65
  66         delete[] buffer;
  67 #else
  68         int const code = WEXITSTATUS (system (cmd.c_str ()));
  69 #endif
  70         if (code) {
  71                 stringstream s;
  72                 s << "error " << code << " in " << cmd << " within " << boost::filesystem::current_path();
  73                 throw libdcp::MiscError (s.str());
  74         }
  75 }
  76
  77 /** Extract a public key from a private key and create a SHA1 digest of it.
  78  *  @param key Private key
  79  *  @param openssl openssl binary name (or full path if openssl is not on the system path).
  80  *  @return SHA1 digest of corresponding public key, with escaped / characters.
  81  */
  82
  83 static string
  84 public_key_digest (boost::filesystem::path private_key, boost::filesystem::path openssl)
  85 {
  86         boost::filesystem::path public_name = private_key.string() + ".public";
  87
  88         /* Create the public key from the private key */
  89         stringstream s;
  90         s << "\"" << openssl.string() << "\" rsa -outform PEM -pubout -in " << private_key.string() << " -out " << public_name.string ();
  91         command (s.str().c_str ());
  92
  93         /* Read in the public key from the file */
  94
  95         string pub;
  96         ifstream f (public_name.string().c_str ());
  97
  98         bool read = false;
  99         while (f.good ()) {
 100                 string line;
 101                 getline (f, line);
 102                 if (line.length() >= 10 && line.substr(0, 10) == "-----BEGIN") {
 103                         read = true;
 104                 } else if (line.length() >= 8 && line.substr(0, 8) == "-----END") {
 105                         break;
 106                 } else if (read) {
 107                         pub += line;
 108                 }
 109         }
 110
 111         /* Decode the base64 of the public key */
 112
 113         unsigned char buffer[512];
 114         int const N = libdcp::base64_decode (pub, buffer, 1024);
 115
 116         /* Hash it with SHA1 (without the first 24 bytes, for reasons that are not entirely clear) */
 117
 118         SHA_CTX context;
 119         if (!SHA1_Init (&context)) {
 120                 throw libdcp::MiscError ("could not init SHA1 context");
 121         }
 122
 123         if (!SHA1_Update (&context, buffer + 24, N - 24)) {
 124                 throw libdcp::MiscError ("could not update SHA1 digest");
 125         }
 126
 127         unsigned char digest[SHA_DIGEST_LENGTH];
 128         if (!SHA1_Final (digest, &context)) {
 129                 throw libdcp::MiscError ("could not finish SHA1 digest");
 130         }
 131
 132         char digest_base64[64];
 133         string dig = Kumu::base64encode (digest, SHA_DIGEST_LENGTH, digest_base64, 64);
 134 #ifdef LIBDCP_WINDOWS
 135         boost::replace_all (dig, "/", "\\/");
 136 #else
 137         boost::replace_all (dig, "/", "\\\\/");
 138 #endif
 139         return dig;
 140 }
 141
 142 void
 143 libdcp::make_signer_chain (boost::filesystem::path directory, boost::filesystem::path openssl)
 144 {
 145         boost::filesystem::path const cwd = boost::filesystem::current_path ();
 146
 147         string quoted_openssl = "\"" + openssl.string() + "\"";
 148
 149         boost::filesystem::current_path (directory);
 150         command (quoted_openssl + " genrsa -out ca.key 2048");
 151
 152         {
 153                 ofstream f ("ca.cnf");
 154                 f << "[ req ]\n"
 155                   << "distinguished_name = req_distinguished_name\n"
 156                   << "x509_extensions   = v3_ca\n"
 157                   << "[ v3_ca ]\n"
 158                   << "basicConstraints = critical,CA:true,pathlen:3\n"
 159                   << "keyUsage = keyCertSign,cRLSign\n"
 160                   << "subjectKeyIdentifier = hash\n"
 161                   << "authorityKeyIdentifier = keyid:always,issuer:always\n"
 162                   << "[ req_distinguished_name ]\n"
 163                   << "O = Unique organization name\n"
 164                   << "OU = Organization unit\n"
 165                   << "CN = Entity and dnQualifier\n";
 166         }
 167
 168         string const ca_subject = "/O=example.org/OU=example.org/CN=.smpte-430-2.ROOT.NOT_FOR_PRODUCTION/dnQualifier=" + public_key_digest ("ca.key", openssl);
 169
 170         {
 171                 stringstream c;
 172                 c << quoted_openssl
 173                   << " req -new -x509 -sha256 -config ca.cnf -days 3650 -set_serial 5"
 174                   << " -subj " << ca_subject << " -key ca.key -outform PEM -out ca.self-signed.pem";
 175                 command (c.str().c_str());
 176         }
 177
 178         command (quoted_openssl + " genrsa -out intermediate.key 2048");
 179
 180         {
 181                 ofstream f ("intermediate.cnf");
 182                 f << "[ default ]\n"
 183                   << "distinguished_name = req_distinguished_name\n"
 184                   << "x509_extensions = v3_ca\n"
 185                   << "[ v3_ca ]\n"
 186                   << "basicConstraints = critical,CA:true,pathlen:2\n"
 187                   << "keyUsage = keyCertSign,cRLSign\n"
 188                   << "subjectKeyIdentifier = hash\n"
 189                   << "authorityKeyIdentifier = keyid:always,issuer:always\n"
 190                   << "[ req_distinguished_name ]\n"
 191                   << "O = Unique organization name\n"
 192                   << "OU = Organization unit\n"
 193                   << "CN = Entity and dnQualifier\n";
 194         }
 195
 196         string const inter_subject = "/O=example.org/OU=example.org/CN=.smpte-430-2.INTERMEDIATE.NOT_FOR_PRODUCTION/dnQualifier="
 197                 + public_key_digest ("intermediate.key", openssl);
 198
 199         {
 200                 stringstream s;
 201                 s << quoted_openssl
 202                   << " req -new -config intermediate.cnf -days 3649 -subj " << inter_subject << " -key intermediate.key -out intermediate.csr";
 203                 command (s.str().c_str());
 204         }
 205
 206
 207         command (
 208                 quoted_openssl +
 209                 " x509 -req -sha256 -days 3649 -CA ca.self-signed.pem -CAkey ca.key -set_serial 6"
 210                 " -in intermediate.csr -extfile intermediate.cnf -extensions v3_ca -out intermediate.signed.pem"
 211                 );
 212
 213         command (quoted_openssl + " genrsa -out leaf.key 2048");
 214
 215         {
 216                 ofstream f ("leaf.cnf");
 217                 f << "[ default ]\n"
 218                   << "distinguished_name = req_distinguished_name\n"
 219                   << "x509_extensions   = v3_ca\n"
 220                   << "[ v3_ca ]\n"
 221                   << "basicConstraints = critical,CA:false\n"
 222                   << "keyUsage = digitalSignature,keyEncipherment\n"
 223                   << "subjectKeyIdentifier = hash\n"
 224                   << "authorityKeyIdentifier = keyid,issuer:always\n"
 225                   << "[ req_distinguished_name ]\n"
 226                   << "O = Unique organization name\n"
 227                   << "OU = Organization unit\n"
 228                   << "CN = Entity and dnQualifier\n";
 229         }
 230
 231         string const leaf_subject = "/O=example.org/OU=example.org/CN=CS.smpte-430-2.LEAF.NOT_FOR_PRODUCTION/dnQualifier="
 232                 + public_key_digest ("leaf.key", openssl);
 233
 234         {
 235                 stringstream s;
 236                 s << quoted_openssl << " req -new -config leaf.cnf -days 3648 -subj " << leaf_subject << " -key leaf.key -outform PEM -out leaf.csr";
 237                 command (s.str().c_str());
 238         }
 239
 240         command (
 241                 quoted_openssl +
 242                 " x509 -req -sha256 -days 3648 -CA intermediate.signed.pem -CAkey intermediate.key"
 243                 " -set_serial 7 -in leaf.csr -extfile leaf.cnf -extensions v3_ca -out leaf.signed.pem"
 244                 );
 245
 246         boost::filesystem::current_path (cwd);
 247 }