src/ssl/certificate_db.cc

   1 /*
   2  * Copyright (C) 1996-2014 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #include "squid.h"
  10 #include "ssl/certificate_db.h"
  11
  12 #include <cerrno>
  13 #include <fstream>
  14 #include <stdexcept>
  15 #if HAVE_SYS_STAT_H
  16 #include <sys/stat.h>
  17 #endif
  18 #if HAVE_SYS_FILE_H
  19 #include <sys/file.h>
  20 #endif
  21 #if HAVE_FCNTL_H
  22 #include <fcntl.h>
  23 #endif
  24
  25 #define HERE "(ssl_crtd) " << __FILE__ << ':' << __LINE__ << ": "
  26
  27 Ssl::Lock::Lock(std::string const &aFilename) :
  28         filename(aFilename),
  29 #if _SQUID_WINDOWS_
  30         hFile(INVALID_HANDLE_VALUE)
  31 #else
  32         fd(-1)
  33 #endif
  34 {
  35 }
  36
  37 bool Ssl::Lock::locked() const
  38 {
  39 #if _SQUID_WINDOWS_
  40     return hFile != INVALID_HANDLE_VALUE;
  41 #else
  42     return fd != -1;
  43 #endif
  44 }
  45
  46 void Ssl::Lock::lock()
  47 {
  48
  49 #if _SQUID_WINDOWS_
  50     hFile = CreateFile(TEXT(filename.c_str()), GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
  51     if (hFile == INVALID_HANDLE_VALUE)
  52 #else
  53     fd = open(filename.c_str(), 0);
  54     if (fd == -1)
  55 #endif
  56         throw std::runtime_error("Failed to open file " + filename);
  57
  58 #if _SQUID_WINDOWS_
  59     if (!LockFile(hFile, 0, 0, 1, 0))
  60 #else
  61     if (flock(fd, LOCK_EX) != 0)
  62 #endif
  63         throw std::runtime_error("Failed to get a lock of " + filename);
  64 }
  65
  66 void Ssl::Lock::unlock()
  67 {
  68 #if _SQUID_WINDOWS_
  69     if (hFile != INVALID_HANDLE_VALUE) {
  70         UnlockFile(hFile, 0, 0, 1, 0);
  71         CloseHandle(hFile);
  72         hFile = INVALID_HANDLE_VALUE;
  73     }
  74 #else
  75     if (fd != -1) {
  76         flock(fd, LOCK_UN);
  77         close(fd);
  78         fd = -1;
  79     }
  80 #endif
  81     else
  82         throw std::runtime_error("Lock is already unlocked for " + filename);
  83 }
  84
  85 Ssl::Lock::~Lock()
  86 {
  87     if (locked())
  88         unlock();
  89 }
  90
  91 Ssl::Locker::Locker(Lock &aLock, const char *aFileName, int aLineNo):
  92         weLocked(false), lock(aLock), fileName(aFileName), lineNo(aLineNo)
  93 {
  94     if (!lock.locked()) {
  95         lock.lock();
  96         weLocked = true;
  97     }
  98 }
  99
 100 Ssl::Locker::~Locker()
 101 {
 102     if (weLocked)
 103         lock.unlock();
 104 }
 105
 106 Ssl::CertificateDb::Row::Row()
 107         :   width(cnlNumber)
 108 {
 109     row = (char **)OPENSSL_malloc(sizeof(char *) * (width + 1));
 110     for (size_t i = 0; i < width + 1; ++i)
 111         row[i] = NULL;
 112 }
 113
 114 Ssl::CertificateDb::Row::Row(char **aRow, size_t aWidth): width(aWidth)
 115 {
 116     row = aRow;
 117 }
 118
 119 Ssl::CertificateDb::Row::~Row()
 120 {
 121     if (!row)
 122         return;
 123
 124     void *max;
 125     if ((max = (void *)row[width]) != NULL) {
 126         // It is an openSSL allocated row. The TXT_DB_read function stores the
 127         // index and row items one one memory segment. The row[width] points
 128         // to the end of buffer. We have to check for items in the array which
 129         // are not stored in this segment. These items should released.
 130         for (size_t i = 0; i < width + 1; ++i) {
 131             if (((row[i] < (char *)row) || (row[i] > max)) && (row[i] != NULL))
 132                 OPENSSL_free(row[i]);
 133         }
 134     } else {
 135         for (size_t i = 0; i < width + 1; ++i) {
 136             if (row[i])
 137                 OPENSSL_free(row[i]);
 138         }
 139     }
 140     OPENSSL_free(row);
 141 }
 142
 143 void Ssl::CertificateDb::Row::reset()
 144 {
 145     row = NULL;
 146 }
 147
 148 void Ssl::CertificateDb::Row::setValue(size_t cell, char const * value)
 149 {
 150     assert(cell < width);
 151     if (row[cell]) {
 152         free(row[cell]);
 153     }
 154     if (value) {
 155         row[cell] = static_cast<char *>(OPENSSL_malloc(sizeof(char) * (strlen(value) + 1)));
 156         memcpy(row[cell], value, sizeof(char) * (strlen(value) + 1));
 157     } else
 158         row[cell] = NULL;
 159 }
 160
 161 char ** Ssl::CertificateDb::Row::getRow()
 162 {
 163     return row;
 164 }
 165
 166 void Ssl::CertificateDb::sq_TXT_DB_delete(TXT_DB *db, const char **row)
 167 {
 168     if (!db)
 169         return;
 170
 171 #if SQUID_SSLTXTDB_PSTRINGDATA
 172     for (int i = 0; i < sk_OPENSSL_PSTRING_num(db->data); ++i) {
 173 #if SQUID_STACKOF_PSTRINGDATA_HACK
 174         const char ** current_row = ((const char **)sk_value(CHECKED_STACK_OF(OPENSSL_PSTRING, db->data), i));
 175 #else
 176         const char ** current_row = ((const char **)sk_OPENSSL_PSTRING_value(db->data, i));
 177 #endif
 178 #else
 179     for (int i = 0; i < sk_num(db->data); ++i) {
 180         const char ** current_row = ((const char **)sk_value(db->data, i));
 181 #endif
 182         if (current_row == row) {
 183             sq_TXT_DB_delete_row(db, i);
 184             return;
 185         }
 186     }
 187 }
 188
 189 #define countof(arr) (sizeof(arr)/sizeof(*arr))
 190 void Ssl::CertificateDb::sq_TXT_DB_delete_row(TXT_DB *db, int idx) {
 191     char **rrow;
 192 #if SQUID_SSLTXTDB_PSTRINGDATA
 193     rrow = (char **)sk_OPENSSL_PSTRING_delete(db->data, idx);
 194 #else
 195     rrow = (char **)sk_delete(db->data, idx);
 196 #endif
 197
 198     if (!rrow)
 199         return;
 200
 201     Row row(rrow, cnlNumber); // row wrapper used to free the rrow
 202
 203     const Columns db_indexes[]={cnlSerial, cnlName};
 204     for (unsigned int i = 0; i < countof(db_indexes); ++i) {
 205         void *data = NULL;
 206 #if SQUID_SSLTXTDB_PSTRINGDATA
 207         if (LHASH_OF(OPENSSL_STRING) *fieldIndex =  db->index[db_indexes[i]])
 208             data = lh_OPENSSL_STRING_delete(fieldIndex, rrow);
 209 #else
 210         if (LHASH *fieldIndex = db->index[db_indexes[i]])
 211             data = lh_delete(fieldIndex, rrow);
 212 #endif
 213         if (data)
 214             assert(data == rrow);
 215     }
 216 }
 217
 218 unsigned long Ssl::CertificateDb::index_serial_hash(const char **a) {
 219     const char *n = a[Ssl::CertificateDb::cnlSerial];
 220     while (*n == '0')
 221         ++n;
 222     return lh_strhash(n);
 223 }
 224
 225 int Ssl::CertificateDb::index_serial_cmp(const char **a, const char **b) {
 226     const char *aa, *bb;
 227     for (aa = a[Ssl::CertificateDb::cnlSerial]; *aa == '0'; ++aa);
 228     for (bb = b[Ssl::CertificateDb::cnlSerial]; *bb == '0'; ++bb);
 229     return strcmp(aa, bb);
 230 }
 231
 232 unsigned long Ssl::CertificateDb::index_name_hash(const char **a) {
 233     return(lh_strhash(a[Ssl::CertificateDb::cnlName]));
 234 }
 235
 236 int Ssl::CertificateDb::index_name_cmp(const char **a, const char **b) {
 237     return(strcmp(a[Ssl::CertificateDb::cnlName], b[CertificateDb::cnlName]));
 238 }
 239
 240 const std::string Ssl::CertificateDb::db_file("index.txt");
 241 const std::string Ssl::CertificateDb::cert_dir("certs");
 242 const std::string Ssl::CertificateDb::size_file("size");
 243
 244 Ssl::CertificateDb::CertificateDb(std::string const & aDb_path, size_t aMax_db_size, size_t aFs_block_size)
 245         :  db_path(aDb_path),
 246         db_full(aDb_path + "/" + db_file),
 247         cert_full(aDb_path + "/" + cert_dir),
 248         size_full(aDb_path + "/" + size_file),
 249         db(NULL),
 250         max_db_size(aMax_db_size),
 251         fs_block_size(aFs_block_size),
 252         dbLock(db_full),
 253         enabled_disk_store(true) {
 254     if (db_path.empty() && !max_db_size)
 255         enabled_disk_store = false;
 256     else if ((db_path.empty() && max_db_size) || (!db_path.empty() && !max_db_size))
 257         throw std::runtime_error("ssl_crtd is missing the required parameter. There should be -s and -M parameters together.");
 258 }
 259
 260 bool Ssl::CertificateDb::find(std::string const & host_name, Ssl::X509_Pointer & cert, Ssl::EVP_PKEY_Pointer & pkey) {
 261     const Locker locker(dbLock, Here);
 262     load();
 263     return pure_find(host_name, cert, pkey);
 264 }
 265
 266 bool Ssl::CertificateDb::purgeCert(std::string const & key) {
 267     const Locker locker(dbLock, Here);
 268     load();
 269     if (!db)
 270         return false;
 271
 272     if (!deleteByHostname(key))
 273         return false;
 274
 275     save();
 276     return true;
 277 }
 278
 279 bool Ssl::CertificateDb::addCertAndPrivateKey(Ssl::X509_Pointer & cert, Ssl::EVP_PKEY_Pointer & pkey, std::string const & useName) {
 280     const Locker locker(dbLock, Here);
 281     load();
 282     if (!db || !cert || !pkey)
 283         return false;
 284     Row row;
 285     ASN1_INTEGER * ai = X509_get_serialNumber(cert.get());
 286     std::string serial_string;
 287     Ssl::BIGNUM_Pointer serial(ASN1_INTEGER_to_BN(ai, NULL));
 288     {
 289         TidyPointer<char, tidyFree> hex_bn(BN_bn2hex(serial.get()));
 290         serial_string = std::string(hex_bn.get());
 291     }
 292     row.setValue(cnlSerial, serial_string.c_str());
 293     char ** rrow = TXT_DB_get_by_index(db.get(), cnlSerial, row.getRow());
 294     // We are creating certificates with unique serial numbers. If the serial
 295     // number is found in the database, the same certificate is already stored.
 296     if (rrow != NULL) {
 297         // TODO: check if the stored row is valid.
 298         return true;
 299     }
 300
 301     {
 302         TidyPointer<char, tidyFree> subject(X509_NAME_oneline(X509_get_subject_name(cert.get()), NULL, 0));
 303         Ssl::X509_Pointer findCert;
 304         Ssl::EVP_PKEY_Pointer findPkey;
 305         if (pure_find(useName.empty() ? subject.get() : useName, findCert, findPkey)) {
 306             // Replace with database certificate
 307             cert.reset(findCert.release());
 308             pkey.reset(findPkey.release());
 309             return true;
 310         }
 311         // pure_find may fail because the entry is expired, or because the
 312         // certs file is corrupted. Remove any entry with given hostname
 313         deleteByHostname(useName.empty() ? subject.get() : useName);
 314     }
 315
 316     // check db size while trying to minimize calls to size()
 317     while (size() > max_db_size) {
 318         if (deleteInvalidCertificate())
 319             continue; // try to find another invalid certificate if needed
 320
 321         // there are no more invalid ones, but there must be valid certificates
 322         do {
 323             if (!deleteOldestCertificate()) {
 324                 save(); // Some entries may have been removed. Update the index file.
 325                 return false; // errors prevented us from freeing enough space
 326             }
 327         } while (size() > max_db_size);
 328         break;
 329     }
 330
 331     row.setValue(cnlType, "V");
 332     ASN1_UTCTIME * tm = X509_get_notAfter(cert.get());
 333     row.setValue(cnlExp_date, std::string(reinterpret_cast<char *>(tm->data), tm->length).c_str());
 334     row.setValue(cnlFile, "unknown");
 335     if (!useName.empty())
 336         row.setValue(cnlName, useName.c_str());
 337     else {
 338         TidyPointer<char, tidyFree> subject(X509_NAME_oneline(X509_get_subject_name(cert.get()), NULL, 0));
 339         row.setValue(cnlName, subject.get());
 340     }
 341
 342     if (!TXT_DB_insert(db.get(), row.getRow())) {
 343         // failed to add index (???) but we may have already modified
 344         // the database so save before exit
 345         save();
 346         return false;
 347     }
 348     rrow = row.getRow();
 349     row.reset();
 350
 351     std::string filename(cert_full + "/" + serial_string + ".pem");
 352     if (!writeCertAndPrivateKeyToFile(cert, pkey, filename.c_str())) {
 353         //remove row from txt_db and save
 354         sq_TXT_DB_delete(db.get(), (const char **)rrow);
 355         save();
 356         return false;
 357     }
 358     addSize(filename);
 359
 360     save();
 361     return true;
 362 }
 363
 364 void Ssl::CertificateDb::create(std::string const & db_path) {
 365     if (db_path == "")
 366         throw std::runtime_error("Path to db is empty");
 367     std::string db_full(db_path + "/" + db_file);
 368     std::string cert_full(db_path + "/" + cert_dir);
 369     std::string size_full(db_path + "/" + size_file);
 370
 371     if (mkdir(db_path.c_str(), 0777))
 372         throw std::runtime_error("Cannot create " + db_path);
 373
 374     if (mkdir(cert_full.c_str(), 0777))
 375         throw std::runtime_error("Cannot create " + cert_full);
 376
 377     std::ofstream size(size_full.c_str());
 378     if (size)
 379         size << 0;
 380     else
 381         throw std::runtime_error("Cannot open " + size_full + " to open");
 382     std::ofstream db(db_full.c_str());
 383     if (!db)
 384         throw std::runtime_error("Cannot open " + db_full + " to open");
 385 }
 386
 387 void Ssl::CertificateDb::check(std::string const & db_path, size_t max_db_size) {
 388     CertificateDb db(db_path, max_db_size, 0);
 389     db.load();
 390 }
 391
 392 bool Ssl::CertificateDb::pure_find(std::string const & host_name, Ssl::X509_Pointer & cert, Ssl::EVP_PKEY_Pointer & pkey) {
 393     if (!db)
 394         return false;
 395
 396     Row row;
 397     row.setValue(cnlName, host_name.c_str());
 398
 399     char **rrow = TXT_DB_get_by_index(db.get(), cnlName, row.getRow());
 400     if (rrow == NULL)
 401         return false;
 402
 403     if (!sslDateIsInTheFuture(rrow[cnlExp_date]))
 404         return false;
 405
 406     // read cert and pkey from file.
 407     std::string filename(cert_full + "/" + rrow[cnlSerial] + ".pem");
 408     readCertAndPrivateKeyFromFiles(cert, pkey, filename.c_str(), NULL);
 409     if (!cert || !pkey)
 410         return false;
 411     return true;
 412 }
 413
 414 size_t Ssl::CertificateDb::size() const {
 415     return readSize();
 416 }
 417
 418 void Ssl::CertificateDb::addSize(std::string const & filename) {
 419     writeSize(readSize() + getFileSize(filename));
 420 }
 421
 422 void Ssl::CertificateDb::subSize(std::string const & filename) {
 423     writeSize(readSize() - getFileSize(filename));
 424 }
 425
 426 size_t Ssl::CertificateDb::readSize() const {
 427     std::ifstream ifstr(size_full.c_str());
 428     if (!ifstr && enabled_disk_store)
 429         throw std::runtime_error("cannot open for reading: " + size_full);
 430     size_t db_size = 0;
 431     if (!(ifstr >> db_size))
 432         throw std::runtime_error("error while reading " + size_full);
 433     return db_size;
 434 }
 435
 436 void Ssl::CertificateDb::writeSize(size_t db_size) {
 437     std::ofstream ofstr(size_full.c_str());
 438     if (!ofstr && enabled_disk_store)
 439         throw std::runtime_error("cannot write \"" + size_full + "\" file");
 440     ofstr << db_size;
 441 }
 442
 443 size_t Ssl::CertificateDb::getFileSize(std::string const & filename) {
 444     std::ifstream file(filename.c_str(), std::ios::binary);
 445     file.seekg(0, std::ios_base::end);
 446     size_t file_size = file.tellg();
 447     return ((file_size + fs_block_size - 1) / fs_block_size) * fs_block_size;
 448 }
 449
 450 void Ssl::CertificateDb::load() {
 451     // Load db from file.
 452     Ssl::BIO_Pointer in(BIO_new(BIO_s_file()));
 453     if (!in || BIO_read_filename(in.get(), db_full.c_str()) <= 0)
 454         throw std::runtime_error("Uninitialized SSL certificate database directory: " + db_path + ". To initialize, run \"ssl_crtd -c -s " + db_path + "\".");
 455
 456     bool corrupt = false;
 457     Ssl::TXT_DB_Pointer temp_db(TXT_DB_read(in.get(), cnlNumber));
 458     if (!temp_db)
 459         corrupt = true;
 460
 461     // Create indexes in db.
 462     if (!corrupt && !TXT_DB_create_index(temp_db.get(), cnlSerial, NULL, LHASH_HASH_FN(index_serial_hash), LHASH_COMP_FN(index_serial_cmp)))
 463         corrupt = true;
 464
 465     if (!corrupt && !TXT_DB_create_index(temp_db.get(), cnlName, NULL, LHASH_HASH_FN(index_name_hash), LHASH_COMP_FN(index_name_cmp)))
 466         corrupt = true;
 467
 468     if (corrupt)
 469         throw std::runtime_error("The SSL certificate database " + db_path + " is corrupted. Please rebuild");
 470
 471     db.reset(temp_db.release());
 472 }
 473
 474 void Ssl::CertificateDb::save() {
 475     if (!db)
 476         throw std::runtime_error("The certificates database is not loaded");;
 477
 478     // To save the db to file,  create a new BIO with BIO file methods.
 479     Ssl::BIO_Pointer out(BIO_new(BIO_s_file()));
 480     if (!out || !BIO_write_filename(out.get(), const_cast<char *>(db_full.c_str())))
 481         throw std::runtime_error("Failed to initialize " + db_full + " file for writing");;
 482
 483     if (TXT_DB_write(out.get(), db.get()) < 0)
 484         throw std::runtime_error("Failed to write " + db_full + " file");
 485 }
 486
 487 // Normally defined in defines.h file
 488 void Ssl::CertificateDb::deleteRow(const char **row, int rowIndex) {
 489     const std::string filename(cert_full + "/" + row[cnlSerial] + ".pem");
 490     sq_TXT_DB_delete_row(db.get(), rowIndex);
 491
 492     subSize(filename);
 493     int ret = remove(filename.c_str());
 494     if (ret < 0 && errno != ENOENT)
 495         throw std::runtime_error("Failed to remove certficate file " + filename + " from db");
 496 }
 497
 498 bool Ssl::CertificateDb::deleteInvalidCertificate() {
 499     if (!db)
 500         return false;
 501
 502     bool removed_one = false;
 503 #if SQUID_SSLTXTDB_PSTRINGDATA
 504     for (int i = 0; i < sk_OPENSSL_PSTRING_num(db.get()->data); ++i) {
 505 #if SQUID_STACKOF_PSTRINGDATA_HACK
 506         const char ** current_row = ((const char **)sk_value(CHECKED_STACK_OF(OPENSSL_PSTRING, db.get()->data), i));
 507 #else
 508         const char ** current_row = ((const char **)sk_OPENSSL_PSTRING_value(db.get()->data, i));
 509 #endif
 510 #else
 511     for (int i = 0; i < sk_num(db.get()->data); ++i) {
 512         const char ** current_row = ((const char **)sk_value(db.get()->data, i));
 513 #endif
 514
 515         if (!sslDateIsInTheFuture(current_row[cnlExp_date])) {
 516             deleteRow(current_row, i);
 517             removed_one = true;
 518             break;
 519         }
 520     }
 521
 522     if (!removed_one)
 523         return false;
 524     return true;
 525 }
 526
 527 bool Ssl::CertificateDb::deleteOldestCertificate() {
 528     if (!db)
 529         return false;
 530
 531 #if SQUID_SSLTXTDB_PSTRINGDATA
 532     if (sk_OPENSSL_PSTRING_num(db.get()->data) == 0)
 533 #else
 534     if (sk_num(db.get()->data) == 0)
 535 #endif
 536         return false;
 537
 538 #if SQUID_SSLTXTDB_PSTRINGDATA
 539 #if SQUID_STACKOF_PSTRINGDATA_HACK
 540     const char **row = ((const char **)sk_value(CHECKED_STACK_OF(OPENSSL_PSTRING, db.get()->data), 0));
 541 #else
 542     const char **row = (const char **)sk_OPENSSL_PSTRING_value(db.get()->data, 0);
 543 #endif
 544 #else
 545     const char **row = (const char **)sk_value(db.get()->data, 0);
 546 #endif
 547
 548     deleteRow(row, 0);
 549
 550     return true;
 551 }
 552
 553 bool Ssl::CertificateDb::deleteByHostname(std::string const & host) {
 554     if (!db)
 555         return false;
 556
 557 #if SQUID_SSLTXTDB_PSTRINGDATA
 558     for (int i = 0; i < sk_OPENSSL_PSTRING_num(db.get()->data); ++i) {
 559 #if SQUID_STACKOF_PSTRINGDATA_HACK
 560         const char ** current_row = ((const char **)sk_value(CHECKED_STACK_OF(OPENSSL_PSTRING, db.get()->data), i));
 561 #else
 562         const char ** current_row = ((const char **)sk_OPENSSL_PSTRING_value(db.get()->data, i));
 563 #endif
 564 #else
 565     for (int i = 0; i < sk_num(db.get()->data); ++i) {
 566         const char ** current_row = ((const char **)sk_value(db.get()->data, i));
 567 #endif
 568         if (host == current_row[cnlName]) {
 569             deleteRow(current_row, i);
 570             return true;
 571         }
 572     }
 573     return false;
 574 }
 575
 576 bool Ssl::CertificateDb::IsEnabledDiskStore() const {
 577     return enabled_disk_store;
 578 }