mcs/class/Mono.Security/Mono.Security.Authenticode/AuthenticodeFormatter.cs

   1 //
   2 // AuthenticodeFormatter.cs: Authenticode signature generator
   3 //
   4 // Author:
   5 //      Sebastien Pouliot <sebastien@ximian.com>
   6 //
   7 // (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   8 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System;
  31 using System.Collections;
  32 using System.Globalization;
  33 using System.IO;
  34 using System.Security.Cryptography;
  35 using System.Text;
  36 using System.Net;
  37
  38 using Mono.Security;
  39 using Mono.Security.X509;
  40
  41 namespace Mono.Security.Authenticode {
  42
  43         public class AuthenticodeFormatter : AuthenticodeBase {
  44
  45                 private Authority authority;
  46                 private X509CertificateCollection certs;
  47                 private ArrayList crls;
  48                 private string hash;
  49                 private RSA rsa;
  50                 private Uri timestamp;
  51                 private ASN1 authenticode;
  52                 private PKCS7.SignedData pkcs7;
  53                 private string description;
  54                 private Uri url;
  55                 private byte [] entry;
  56
  57                 public AuthenticodeFormatter () : base ()
  58                 {
  59                         certs = new X509CertificateCollection ();
  60                         crls = new ArrayList ();
  61                         authority = Authority.Maximum;
  62                         pkcs7 = new PKCS7.SignedData ();
  63                 }
  64
  65                 public Authority Authority {
  66                         get { return authority; }
  67                         set { authority = value; }
  68                 }
  69
  70                 public X509CertificateCollection Certificates {
  71                         get { return certs; }
  72                 }
  73
  74                 public ArrayList Crl {
  75                         get { return crls; }
  76                 }
  77
  78                 public string Hash {
  79                         get {
  80                                 if (hash == null)
  81                                         hash = "MD5";
  82                                 return hash;
  83                         }
  84                         set {
  85                                 if (value == null)
  86                                         throw new ArgumentNullException ("Hash");
  87
  88                                 string h = value.ToUpper (CultureInfo.InvariantCulture);
  89                                 switch (h) {
  90                                         case "MD5":
  91                                         case "SHA1":
  92                                                 hash = h;
  93                                                 break;
  94                                         default:
  95                                                 throw new ArgumentException ("Invalid Authenticode hash algorithm");
  96                                 }
  97                         }
  98                 }
  99
 100                 public RSA RSA {
 101                         get { return rsa; }
 102                         set { rsa = value; }
 103                 }
 104
 105                 public Uri TimestampUrl {
 106                         get { return timestamp; }
 107                         set { timestamp = value; }
 108                 }
 109
 110                 public string Description {
 111                         get { return description; }
 112                         set { description = value; }
 113                 }
 114
 115                 public Uri Url {
 116                         get { return url; }
 117                         set { url = value; }
 118                 }
 119
 120                 private ASN1 AlgorithmIdentifier (string oid)
 121                 {
 122                         ASN1 ai = new ASN1 (0x30);
 123                         ai.Add (ASN1Convert.FromOid (oid));
 124                         ai.Add (new ASN1 (0x05));       // NULL
 125                         return ai;
 126                 }
 127
 128                 private ASN1 Attribute (string oid, ASN1 value)
 129                 {
 130                         ASN1 attr = new ASN1 (0x30);
 131                         attr.Add (ASN1Convert.FromOid (oid));
 132                         ASN1 aset = attr.Add (new ASN1 (0x31));
 133                         aset.Add (value);
 134                         return attr;
 135                 }
 136
 137                 private ASN1 Opus (string description, string url)
 138                 {
 139                         ASN1 opus = new ASN1 (0x30);
 140                         if (description != null) {
 141                                 ASN1 part1 = opus.Add (new ASN1 (0xA0));
 142                                 part1.Add (new ASN1 (0x80, Encoding.BigEndianUnicode.GetBytes (description)));
 143                         }
 144                         if (url != null) {
 145                                 ASN1 part2 = opus.Add (new ASN1 (0xA1));
 146                                 part2.Add (new ASN1 (0x80, Encoding.ASCII.GetBytes (url)));
 147                         }
 148                         return opus;
 149                 }
 150
 151                 // pkcs 1
 152 //              private const string rsaEncryption = "1.2.840.113549.1.1.1";
 153                 // pkcs 7
 154 //              private const string data = "1.2.840.113549.1.7.1";
 155                 private const string signedData = "1.2.840.113549.1.7.2";
 156                 // pkcs 9
 157 //              private const string contentType = "1.2.840.113549.1.9.3";
 158 //              private const string messageDigest  = "1.2.840.113549.1.9.4";
 159                 private const string countersignature = "1.2.840.113549.1.9.6";
 160                 // microsoft spc (software publisher certificate)
 161                 private const string spcStatementType = "1.3.6.1.4.1.311.2.1.11";
 162                 private const string spcSpOpusInfo = "1.3.6.1.4.1.311.2.1.12";
 163                 private const string spcPelmageData = "1.3.6.1.4.1.311.2.1.15";
 164 //              private const string individualCodeSigning = "1.3.6.1.4.1.311.2.1.21";
 165                 private const string commercialCodeSigning = "1.3.6.1.4.1.311.2.1.22";
 166                 private const string timestampCountersignature = "1.3.6.1.4.1.311.3.2.1";
 167
 168                 //private static byte[] version = { 0x01 };
 169                 private static byte[] obsolete = { 0x03, 0x01, 0x00, 0xA0, 0x20, 0xA2, 0x1E, 0x80, 0x1C, 0x00, 0x3C, 0x00, 0x3C, 0x00, 0x3C, 0x00, 0x4F, 0x00, 0x62, 0x00, 0x73, 0x00, 0x6F, 0x00, 0x6C, 0x00, 0x65, 0x00, 0x74, 0x00, 0x65, 0x00, 0x3E, 0x00, 0x3E, 0x00, 0x3E };
 170
 171                 private byte[] Header (byte[] fileHash, string hashAlgorithm)
 172                 {
 173                         string hashOid = CryptoConfig.MapNameToOID (hashAlgorithm);
 174                         ASN1 content = new ASN1 (0x30);
 175                         ASN1 c1 = content.Add (new ASN1 (0x30));
 176                         c1.Add (ASN1Convert.FromOid (spcPelmageData));
 177                         c1.Add (new ASN1 (0x30, obsolete));
 178                         ASN1 c2 = content.Add (new ASN1 (0x30));
 179                         c2.Add (AlgorithmIdentifier (hashOid));
 180                         c2.Add (new ASN1 (0x04, fileHash));
 181
 182                         pkcs7.HashName = hashAlgorithm;
 183                         pkcs7.Certificates.AddRange (certs);
 184                         pkcs7.ContentInfo.ContentType = spcIndirectDataContext;
 185                         pkcs7.ContentInfo.Content.Add (content);
 186
 187                         pkcs7.SignerInfo.Certificate = certs [0];
 188                         pkcs7.SignerInfo.Key = rsa;
 189
 190                         ASN1 opus = null;
 191                         if (url == null)
 192                                 opus = Attribute (spcSpOpusInfo, Opus (description, null));
 193                         else
 194                                 opus = Attribute (spcSpOpusInfo, Opus (description, url.ToString ()));
 195                         pkcs7.SignerInfo.AuthenticatedAttributes.Add (opus);
 196                         pkcs7.SignerInfo.AuthenticatedAttributes.Add (Attribute (spcStatementType, new ASN1 (0x30, ASN1Convert.FromOid (commercialCodeSigning).GetBytes ())));
 197                         pkcs7.GetASN1 (); // sign
 198                         return pkcs7.SignerInfo.Signature;
 199                 }
 200
 201                 public ASN1 TimestampRequest (byte[] signature)
 202                 {
 203                         PKCS7.ContentInfo ci = new PKCS7.ContentInfo (PKCS7.Oid.data);
 204                         ci.Content.Add (new ASN1 (0x04, signature));
 205                         return PKCS7.AlgorithmIdentifier (timestampCountersignature, ci.ASN1);
 206                 }
 207
 208                 public void ProcessTimestamp (byte[] response)
 209                 {
 210                         ASN1 ts = new ASN1 (Convert.FromBase64String (Encoding.ASCII.GetString (response)));
 211                         // first validate the received message
 212                         // TODO
 213
 214                         // add the supplied certificates inside our signature
 215                         for (int i=0; i < ts[1][0][3].Count; i++)
 216                                 pkcs7.Certificates.Add (new X509Certificate (ts[1][0][3][i].GetBytes ()));
 217
 218                         // add an unauthentified attribute to our signature
 219                         pkcs7.SignerInfo.UnauthenticatedAttributes.Add (Attribute (countersignature, ts[1][0][4][0]));
 220                 }
 221
 222                 private byte[] Timestamp (byte[] signature)
 223                 {
 224                         ASN1 tsreq = TimestampRequest (signature);
 225                         WebClient wc = new WebClient ();
 226                         wc.Headers.Add ("Content-Type", "application/octet-stream");
 227                         wc.Headers.Add ("Accept", "application/octet-stream");
 228                         byte[] tsdata = Encoding.ASCII.GetBytes (Convert.ToBase64String (tsreq.GetBytes ()));
 229                         return wc.UploadData (timestamp.ToString (), tsdata);
 230                 }
 231
 232                 private byte[] file;
 233                 private int pe_offset = -1;
 234                 private int sec_offset = -1;
 235                 private int sec_size = -1;
 236
 237                 private int PEOffset {
 238                         get {
 239                                 if (file == null)
 240                                         return -1;
 241                                 if (pe_offset == -1) {
 242                                         int peOffset = BitConverterLE.ToInt32 (file, 60);
 243                                         if (peOffset < file.Length)
 244                                                 pe_offset = peOffset;
 245                                 }
 246                                 return pe_offset;
 247                         }
 248                 }
 249
 250                 private int SecurityOffset {
 251                         get {
 252                                 if (file == null)
 253                                         return -1;
 254                                 if (sec_offset == -1) {
 255                                         sec_offset = BitConverterLE.ToInt32 (file, PEOffset + 152);
 256                                 }
 257                                 return sec_offset;
 258                         }
 259                 }
 260
 261                 private int SecuritySize {
 262                         get {
 263                                 if (file == null)
 264                                         return -1;
 265                                 if (sec_size == -1) {
 266                                         sec_size = BitConverterLE.ToInt32 (file, PEOffset + 156);
 267                                 }
 268                                 return sec_size;
 269                         }
 270                 }
 271
 272                 private bool Open (string fileName)
 273                 {
 274                         using (FileStream fs = new FileStream (fileName, FileMode.Open, FileAccess.Read, FileShare.Read)) {
 275                                 file = new byte[fs.Length];
 276                                 fs.Read (file, 0, file.Length);
 277                                 fs.Close ();
 278                         }
 279
 280                         // MZ - DOS header
 281                         if (BitConverterLE.ToUInt16 (file, 0) != 0x5A4D)
 282                                 return false;
 283
 284                         // PE Header
 285                         if (PEOffset == -1)
 286                                 return false;
 287
 288                         // PE - NT header
 289                         if (BitConverterLE.ToUInt16 (file, PEOffset) != 0x4550)
 290                                 return false;
 291
 292                         // IMAGE_DIRECTORY_ENTRY_SECURITY
 293                         if (SecuritySize > 8) {
 294                                 entry = new byte[SecuritySize - 8];
 295                                 Buffer.BlockCopy (file, SecurityOffset + 8, entry, 0, entry.Length);
 296                         } else
 297                                 entry = null;
 298
 299                         return true;
 300                 }
 301
 302                 private bool Save (string fileName, byte[] asn)
 303                 {
 304 #if !DEBUG
 305                         using (FileStream fs = File.Open (fileName + ".sig", FileMode.Create, FileAccess.Write)) {
 306                                 fs.Write (asn, 0, asn.Length);
 307                                 fs.Close ();
 308                         }
 309 #endif
 310                         // someday I may be sure enough to move this into DEBUG ;-)
 311                         File.Copy (fileName, fileName + ".bak", true);
 312
 313                         using (FileStream fs = File.Open (fileName, FileMode.Create, FileAccess.Write)) {
 314                                 int filesize = (SecurityOffset == 0) ? file.Length : SecurityOffset;
 315                                 // IMAGE_DIRECTORY_ENTRY_SECURITY (offset, size)
 316                                 byte[] data = BitConverterLE.GetBytes (filesize);
 317                                 file[PEOffset + 152] = data[0];
 318                                 file[PEOffset + 153] = data[1];
 319                                 file[PEOffset + 154] = data[2];
 320                                 file[PEOffset + 155] = data[3];
 321                                 int size = asn.Length + 8;
 322                                 // must be a multiple of 8 bytes
 323                                 int addsize = (size % 8);
 324                                 if (addsize > 0)
 325                                         addsize = 8 - addsize;
 326                                 size += addsize;
 327                                 data = BitConverterLE.GetBytes (size);          // header
 328                                 file[PEOffset + 156] = data[0];
 329                                 file[PEOffset + 157] = data[1];
 330                                 file[PEOffset + 158] = data[2];
 331                                 file[PEOffset + 159] = data[3];
 332                                 fs.Write (file, 0, filesize);
 333                                 fs.Write (data, 0, data.Length);                // length (again)
 334                                 data = BitConverterLE.GetBytes (0x00020200);    // magic
 335                                 fs.Write (data, 0, data.Length);
 336                                 fs.Write (asn, 0, asn.Length);
 337                                 // fill up
 338                                 byte[] fillup = new byte[addsize];
 339                                 fs.Write (fillup, 0, fillup.Length);
 340                                 fs.Close ();
 341                         }
 342                         return true;
 343                 }
 344
 345                 public bool Sign (string fileName)
 346                 {
 347                         try {
 348                                 if (!Open (fileName))
 349                                         return false;
 350
 351                                 HashAlgorithm hash = HashAlgorithm.Create (Hash);
 352                                 // 0 to 215 (216) then skip 4 (checksum)
 353                                 int pe = PEOffset + 88;
 354                                 hash.TransformBlock (file, 0, pe, file, 0);
 355                                 pe += 4;
 356                                 // 220 to 279 (60) then skip 8 (IMAGE_DIRECTORY_ENTRY_SECURITY)
 357                                 hash.TransformBlock (file, pe, 60, file, pe);
 358                                 pe += 68;
 359                                 // 288 to end of file
 360                                 int n = file.Length - pe;
 361                                 // minus any authenticode signature (with 8 bytes header)
 362                                 if (SecurityOffset != 0)
 363                                         n -= (SecuritySize);
 364                                 hash.TransformFinalBlock (file, pe, n);
 365
 366                                 byte[] signature = Header (hash.Hash, Hash);
 367                                 if (timestamp != null) {
 368                                         byte[] ts = Timestamp (signature);
 369                                         // add timestamp information inside the current pkcs7 SignedData instance
 370                                         // (this is possible because the data isn't yet signed)
 371                                         ProcessTimestamp (ts);
 372                                 }
 373
 374                                 PKCS7.ContentInfo sign = new PKCS7.ContentInfo (signedData);
 375                                 sign.Content.Add (pkcs7.ASN1);
 376                                 authenticode = sign.ASN1;
 377
 378                                 return Save (fileName, authenticode.GetBytes ());
 379                         }
 380                         catch (Exception e) {
 381                                 Console.WriteLine (e);
 382                         }
 383                         return false;
 384                 }
 385
 386                 // in case we just want to timestamp the file
 387                 public bool Timestamp (string fileName)
 388                 {
 389                         try {
 390                                 AuthenticodeDeformatter def = new AuthenticodeDeformatter (fileName);
 391                                 byte[] signature = def.Signature;
 392                                 if ((signature != null) && Open (fileName)) {
 393                                         PKCS7.ContentInfo ci = new PKCS7.ContentInfo (signature);
 394                                         pkcs7 = new PKCS7.SignedData (ci.Content);
 395
 396                                         byte[] response = Timestamp (pkcs7.SignerInfo.Signature);
 397                                         ASN1 ts = new ASN1 (Convert.FromBase64String (Encoding.ASCII.GetString (response)));
 398                                         // insert new certificates and countersignature into the original signature
 399                                         ASN1 asn = new ASN1 (signature);
 400                                         ASN1 content = asn.Element (1, 0xA0);
 401                                         if (content == null)
 402                                                 return false;
 403
 404                                         ASN1 signedData = content.Element (0, 0x30);
 405                                         if (signedData == null)
 406                                                 return false;
 407
 408                                         // add the supplied certificates inside our signature
 409                                         ASN1 certificates = signedData.Element (3, 0xA0);
 410                                         if (certificates == null) {
 411                                                 certificates = new ASN1 (0xA0);
 412                                                 signedData.Add (certificates);
 413                                         }
 414                                         for (int i = 0; i < ts[1][0][3].Count; i++) {
 415                                                 certificates.Add (ts[1][0][3][i]);
 416                                         }
 417
 418                                         // add an unauthentified attribute to our signature
 419                                         ASN1 signerInfoSet = signedData[signedData.Count - 1];
 420                                         ASN1 signerInfo = signerInfoSet[0];
 421                                         ASN1 unauthenticated = signerInfo[signerInfo.Count - 1];
 422                                         if (unauthenticated.Tag != 0xA1) {
 423                                                 unauthenticated = new ASN1 (0xA1);
 424                                                 signerInfo.Add (unauthenticated);
 425                                         }
 426                                         unauthenticated.Add (Attribute (countersignature, ts[1][0][4][0]));
 427
 428                                         return Save (fileName, asn.GetBytes ());
 429                                 }
 430                         }
 431                         catch (Exception e) {
 432                                 Console.WriteLine (e);
 433                         }
 434                         return false;
 435                 }
 436         }
 437 }