xmltooling/security/impl/FilesystemCredentialResolver.cpp

   1 /*
   2  *  Copyright 2001-2007 Internet2
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /**
  18  * FilesystemCredentialResolver.cpp
  19  *
  20  * Supplies credentials from local files
  21  */
  22
  23 #include "internal.h"
  24 #include "security/BasicX509Credential.h"
  25 #include "security/CredentialCriteria.h"
  26 #include "security/CredentialResolver.h"
  27 #include "security/KeyInfoResolver.h"
  28 #include "security/OpenSSLCredential.h"
  29 #include "util/NDC.h"
  30 #include "util/XMLHelper.h"
  31
  32 #include <sys/types.h>
  33 #include <sys/stat.h>
  34 #include <openssl/pkcs12.h>
  35 #include <log4cpp/Category.hh>
  36 #include <xercesc/util/XMLUniDefs.hpp>
  37 #include <xsec/enc/OpenSSL/OpenSSLCryptoX509.hpp>
  38 #include <xsec/enc/OpenSSL/OpenSSLCryptoKeyRSA.hpp>
  39 #include <xsec/enc/OpenSSL/OpenSSLCryptoKeyDSA.hpp>
  40
  41 using namespace xmlsignature;
  42 using namespace xmltooling;
  43 using namespace log4cpp;
  44 using namespace std;
  45
  46 // OpenSSL password callback...
  47 static int passwd_callback(char* buf, int len, int verify, void* passwd)
  48 {
  49     if(!verify)
  50     {
  51         if(passwd && len > strlen(reinterpret_cast<char*>(passwd)))
  52         {
  53             strcpy(buf,reinterpret_cast<char*>(passwd));
  54             return strlen(buf);
  55         }
  56     }
  57     return 0;
  58 }
  59
  60 namespace xmltooling {
  61
  62 #if defined (_MSC_VER)
  63     #pragma warning( push )
  64     #pragma warning( disable : 4250 )
  65 #endif
  66
  67     class XMLTOOL_DLLLOCAL FilesystemCredentialResolver;
  68     class XMLTOOL_DLLLOCAL FilesystemCredential : public OpenSSLCredential, public BasicX509Credential
  69     {
  70     public:
  71         FilesystemCredential(FilesystemCredentialResolver* resolver, XSECCryptoKey* key, const std::vector<XSECCryptoX509*>& xseccerts)
  72                 : BasicX509Credential(key, xseccerts), m_resolver(resolver) {
  73             if (!m_xseccerts.empty())
  74                 extractNames(m_xseccerts.front(), m_keyNames);
  75             initKeyInfo();
  76         }
  77         virtual ~FilesystemCredential() {
  78         }
  79
  80         void addKeyNames(const DOMElement* e);
  81
  82         void attach(SSL_CTX* ctx) const;
  83
  84     private:
  85         FilesystemCredentialResolver* m_resolver;
  86     };
  87
  88 #if defined (_MSC_VER)
  89     #pragma warning( pop )
  90 #endif
  91
  92     class XMLTOOL_DLLLOCAL FilesystemCredentialResolver : public CredentialResolver
  93     {
  94     public:
  95         FilesystemCredentialResolver(const DOMElement* e);
  96         virtual ~FilesystemCredentialResolver() {
  97             delete m_credential;
  98             for_each(m_certs.begin(),m_certs.end(),X509_free);
  99         }
 100
 101         Lockable* lock() { return this; }
 102         void unlock() {}
 103
 104         const Credential* resolve(const CredentialCriteria* criteria=NULL) const {
 105             return (criteria ? (criteria->matches(*m_credential) ? m_credential : NULL) : m_credential);
 106         }
 107
 108         virtual vector<const Credential*>::size_type resolve(
 109             vector<const Credential*>& results, const CredentialCriteria* criteria=NULL
 110             ) const {
 111             if (!criteria || criteria->matches(*m_credential)) {
 112                 results.push_back(m_credential);
 113                 return 1;
 114             }
 115             return 0;
 116         }
 117
 118         void attach(SSL_CTX* ctx) const;
 119
 120     private:
 121         XSECCryptoKey* loadKey();
 122
 123         enum format_t { PEM=SSL_FILETYPE_PEM, DER=SSL_FILETYPE_ASN1, _PKCS12, UNKNOWN };
 124
 125         format_t getEncodingFormat(BIO* in) const;
 126         string formatToString(format_t format) const;
 127         format_t xmlFormatToFormat(const XMLCh* format_xml) const;
 128
 129         format_t m_keyformat;
 130         string m_keypath,m_keypass;
 131         vector<X509*> m_certs;
 132         FilesystemCredential* m_credential;
 133     };
 134
 135     CredentialResolver* XMLTOOL_DLLLOCAL FilesystemCredentialResolverFactory(const DOMElement* const & e)
 136     {
 137         return new FilesystemCredentialResolver(e);
 138     }
 139
 140     static const XMLCh CAPath[] =           UNICODE_LITERAL_6(C,A,P,a,t,h);
 141     static const XMLCh Certificate[] =      UNICODE_LITERAL_11(C,e,r,t,i,f,i,c,a,t,e);
 142     static const XMLCh format[] =           UNICODE_LITERAL_6(f,o,r,m,a,t);
 143     static const XMLCh Key[] =              UNICODE_LITERAL_3(K,e,y);
 144     static const XMLCh Name[] =             UNICODE_LITERAL_4(N,a,m,e);
 145     static const XMLCh password[] =         UNICODE_LITERAL_8(p,a,s,s,w,o,r,d);
 146     static const XMLCh Path[] =             UNICODE_LITERAL_4(P,a,t,h);
 147 };
 148
 149 FilesystemCredentialResolver::FilesystemCredentialResolver(const DOMElement* e) : m_credential(NULL)
 150 {
 151 #ifdef _DEBUG
 152     NDC ndc("FilesystemCredentialResolver");
 153 #endif
 154     Category& log=Category::getInstance(XMLTOOLING_LOGCAT".CredentialResolver."FILESYSTEM_CREDENTIAL_RESOLVER);
 155
 156     const DOMElement* root=e;
 157
 158     XSECCryptoKey* key=NULL;
 159     vector<XSECCryptoX509*> xseccerts;
 160
 161     format_t fformat;
 162     const XMLCh* format_xml=NULL;
 163     BIO* in = NULL;
 164
 165     // Move to Key
 166     const DOMElement* keynode=XMLHelper::getFirstChildElement(root,Key);
 167     if (keynode) {
 168
 169         // Get raw format attrib value, but defer processing til later since may need to
 170         // determine format dynamically, and we need the Path for that.
 171         format_xml=keynode->getAttributeNS(NULL,format);
 172
 173         const XMLCh* password_xml=keynode->getAttributeNS(NULL,password);
 174         if (password_xml) {
 175             auto_ptr_char kp(password_xml);
 176             m_keypass=kp.get();
 177         }
 178
 179         e=XMLHelper::getFirstChildElement(keynode,Path);
 180         if (e && e->hasChildNodes()) {
 181             const XMLCh* s=e->getFirstChild()->getNodeValue();
 182             auto_ptr_char kpath(s);
 183 #ifdef WIN32
 184             struct _stat stat_buf;
 185             if (_stat(kpath.get(), &stat_buf) != 0)
 186 #else
 187             struct stat stat_buf;
 188             if (stat(kpath.get(), &stat_buf) != 0)
 189 #endif
 190             {
 191                 log.error("key file (%s) can't be opened", kpath.get());
 192                 throw XMLSecurityException("FilesystemCredentialResolver can't access key file ($1)",params(1,kpath.get()));
 193             }
 194             m_keypath=kpath.get();
 195         }
 196         else {
 197             log.error("Path element missing inside Key element");
 198             throw XMLSecurityException("FilesystemCredentialResolver can't access key file, no Path element specified.");
 199         }
 200
 201         // Determine the key encoding format dynamically, if not explicitly specified
 202         if (format_xml && *format_xml) {
 203             fformat = xmlFormatToFormat(format_xml);
 204             if (fformat != UNKNOWN) {
 205                 m_keyformat = fformat;
 206             }
 207             else {
 208                 auto_ptr_char unknown(format_xml);
 209                 log.error("configuration specifies unknown key encoding format (%s)", unknown.get());
 210                 throw XMLSecurityException("FilesystemCredentialResolver configuration contains unknown key encoding format ($1)",params(1,unknown.get()));
 211             }
 212         }
 213         else {
 214             in=BIO_new(BIO_s_file_internal());
 215             if (in && BIO_read_filename(in,m_keypath.c_str())>0) {
 216                 m_keyformat = getEncodingFormat(in);
 217                 log.debug("key encoding format for (%s) dynamically resolved as (%s)", m_keypath.c_str(), formatToString(m_keyformat).c_str());
 218             }
 219             else {
 220                 log.error("key file (%s) can't be read to determine encoding format", m_keypath.c_str());
 221                 throw XMLSecurityException("FilesystemCredentialResolver can't read key file ($1) to determine encoding format",params(1,m_keypath.c_str()));
 222             }
 223             if (in)
 224                 BIO_free(in);
 225             in = NULL;
 226         }
 227
 228         // Load the key.
 229         key = loadKey();
 230     }
 231
 232     // Check for Certificate
 233     e=XMLHelper::getFirstChildElement(root,Certificate);
 234     if (!e) {
 235         m_credential = new FilesystemCredential(this,key,xseccerts);
 236         m_credential->addKeyNames(keynode);
 237         return;
 238     }
 239     auto_ptr_char certpass(e->getAttributeNS(NULL,password));
 240
 241     const DOMElement* ep=XMLHelper::getFirstChildElement(e,Path);
 242     if (!ep || !ep->hasChildNodes()) {
 243         log.error("Path element missing inside Certificate element or is empty");
 244         delete key;
 245         throw XMLSecurityException("FilesystemCredentialResolver can't access certificate file, missing or empty Path element.");
 246     }
 247
 248     auto_ptr_char certpath(ep->getFirstChild()->getNodeValue());
 249     format_xml=e->getAttributeNS(NULL,format);
 250     if (format_xml && *format_xml) {
 251         fformat = xmlFormatToFormat(format_xml);
 252         if (fformat == UNKNOWN) {
 253             auto_ptr_char unknown(format_xml);
 254             log.error("configuration specifies unknown certificate encoding format (%s)", unknown.get());
 255             delete key;
 256             throw XMLSecurityException("FilesystemCredentialResolver configuration contains unknown certificate encoding format ($1)",params(1,unknown.get()));
 257         }
 258     }
 259
 260     try {
 261         X509* x=NULL;
 262         PKCS12* p12=NULL;
 263         in=BIO_new(BIO_s_file_internal());
 264         if (in && BIO_read_filename(in,certpath.get())>0) {
 265             if (!format_xml || !*format_xml) {
 266                 // Determine the cert encoding format dynamically, if not explicitly specified
 267                 fformat = getEncodingFormat(in);
 268                 log.debug("certificate encoding format for (%s) dynamically resolved as (%s)", certpath.get(), formatToString(fformat).c_str());
 269             }
 270
 271             switch(fformat) {
 272                 case PEM:
 273                     while (x=PEM_read_bio_X509(in,NULL,passwd_callback,const_cast<char*>(certpass.get())))
 274                         m_certs.push_back(x);
 275                     break;
 276
 277                 case DER:
 278                     x=d2i_X509_bio(in,NULL);
 279                     if (x)
 280                         m_certs.push_back(x);
 281                     else {
 282                         log_openssl();
 283                         BIO_free(in);
 284                         throw XMLSecurityException("FilesystemCredentialResolver unable to load DER certificate from file ($1)",params(1,certpath.get()));
 285                     }
 286                     break;
 287
 288                 case _PKCS12:
 289                     p12=d2i_PKCS12_bio(in,NULL);
 290                     if (p12) {
 291                         PKCS12_parse(p12, certpass.get(), NULL, &x, NULL);
 292                         PKCS12_free(p12);
 293                     }
 294                     if (x) {
 295                         m_certs.push_back(x);
 296                         x=NULL;
 297                     } else {
 298                         log_openssl();
 299                         BIO_free(in);
 300                         throw XMLSecurityException("FilesystemCredentialResolver unable to load PKCS12 certificate from file ($1)",params(1,certpath.get()));
 301                     }
 302                     break;
 303             } // end switch
 304
 305         } else {
 306             log_openssl();
 307             if (in) {
 308                 BIO_free(in);
 309                 in=NULL;
 310             }
 311             throw XMLSecurityException("FilesystemCredentialResolver unable to load certificate(s) from file ($1)",params(1,certpath.get()));
 312         }
 313         if (in) {
 314             BIO_free(in);
 315             in=NULL;
 316         }
 317
 318         if (m_certs.empty())
 319             throw XMLSecurityException("FilesystemCredentialResolver unable to load any certificate(s)");
 320
 321         // Load any extra CA files.
 322         const DOMElement* extra=XMLHelper::getFirstChildElement(e,CAPath);
 323         while (extra) {
 324             if (!extra->hasChildNodes()) {
 325                 log.warn("skipping empty CAPath element");
 326                 extra = XMLHelper::getNextSiblingElement(extra,CAPath);
 327                 continue;
 328             }
 329             auto_ptr_char capath(extra->getFirstChild()->getNodeValue());
 330             x=NULL;
 331             p12=NULL;
 332             in=BIO_new(BIO_s_file_internal());
 333             if (in && BIO_read_filename(in,capath.get())>0) {
 334                 if (!format_xml || !*format_xml) {
 335                     // Determine the cert encoding format dynamically, if not explicitly specified
 336                     fformat = getEncodingFormat(in);
 337                     log.debug("CA certificate encoding format for (%s) dynamically resolved as (%s)", certpath.get(), formatToString(fformat).c_str());
 338                 }
 339
 340                 switch (fformat) {
 341                     case PEM:
 342                         while (x=PEM_read_bio_X509(in,NULL,passwd_callback,const_cast<char*>(certpass.get())))
 343                             m_certs.push_back(x);
 344                         break;
 345
 346                     case DER:
 347                         x=d2i_X509_bio(in,NULL);
 348                         if (x)
 349                             m_certs.push_back(x);
 350                         else {
 351                             log_openssl();
 352                             BIO_free(in);
 353                             throw XMLSecurityException("FilesystemCredentialResolver unable to load DER CA certificate from file ($1)",params(1,capath.get()));
 354                         }
 355                         break;
 356
 357                     case _PKCS12:
 358                         p12 = d2i_PKCS12_bio(in, NULL);
 359                         if (p12) {
 360                             PKCS12_parse(p12, certpass.get(), NULL, &x, NULL);
 361                             PKCS12_free(p12);
 362                         }
 363                         if (x) {
 364                             m_certs.push_back(x);
 365                             x=NULL;
 366                         }
 367                         else {
 368                             log_openssl();
 369                             BIO_free(in);
 370                             throw XMLSecurityException("FilesystemCredentialResolver unable to load PKCS12 CA certificate from file ($1)",params(1,capath.get()));
 371                         }
 372                         break;
 373                 } //end switch
 374
 375                 BIO_free(in);
 376             }
 377             else {
 378                 if (in)
 379                     BIO_free(in);
 380                 log_openssl();
 381                 log.error("CA file (%s) can't be opened", capath.get());
 382                 throw XMLSecurityException("FilesystemCredentialResolver can't open CA file ($1)",params(1,capath.get()));
 383             }
 384
 385             extra = XMLHelper::getNextSiblingElement(extra,CAPath);
 386         }
 387     }
 388     catch (XMLToolingException&) {
 389         delete key;
 390         for_each(m_certs.begin(), m_certs.end(), X509_free);
 391         throw;
 392     }
 393
 394     // Reflect certs over to XSEC form and wrap with credential object.
 395     for (vector<X509*>::iterator j=m_certs.begin(); j!=m_certs.end(); j++)
 396         xseccerts.push_back(new OpenSSLCryptoX509(*j));
 397     if (!key && !xseccerts.empty())
 398         key = xseccerts.front()->clonePublicKey();
 399     m_credential = new FilesystemCredential(this, key, xseccerts);
 400     m_credential->addKeyNames(keynode);
 401 }
 402
 403 XSECCryptoKey* FilesystemCredentialResolver::loadKey()
 404 {
 405 #ifdef _DEBUG
 406     NDC ndc("loadKey");
 407 #endif
 408
 409     // Get a EVP_PKEY.
 410     EVP_PKEY* pkey=NULL;
 411     BIO* in=BIO_new(BIO_s_file_internal());
 412     if (in && BIO_read_filename(in,m_keypath.c_str())>0) {
 413         switch (m_keyformat) {
 414             case PEM:
 415                 pkey=PEM_read_bio_PrivateKey(in, NULL, passwd_callback, const_cast<char*>(m_keypass.c_str()));
 416                 break;
 417
 418             case DER:
 419                 pkey=d2i_PrivateKey_bio(in, NULL);
 420                 break;
 421
 422             default: {
 423                 PKCS12* p12 = d2i_PKCS12_bio(in, NULL);
 424                 if (p12) {
 425                     PKCS12_parse(p12, const_cast<char*>(m_keypass.c_str()), &pkey, NULL, NULL);
 426                     PKCS12_free(p12);
 427                 }
 428             }
 429         }
 430     }
 431     if (in)
 432         BIO_free(in);
 433
 434     // Now map it to an XSEC wrapper.
 435     if (pkey) {
 436         XSECCryptoKey* ret=NULL;
 437         switch (pkey->type) {
 438             case EVP_PKEY_RSA:
 439                 ret=new OpenSSLCryptoKeyRSA(pkey);
 440                 break;
 441
 442             case EVP_PKEY_DSA:
 443                 ret=new OpenSSLCryptoKeyDSA(pkey);
 444                 break;
 445
 446             default:
 447                 Category::getInstance(XMLTOOLING_LOGCAT".CredentialResolver."FILESYSTEM_CREDENTIAL_RESOLVER).error("unsupported private key type");
 448         }
 449         EVP_PKEY_free(pkey);
 450         if (ret)
 451             return ret;
 452     }
 453
 454     log_openssl();
 455     throw XMLSecurityException("FilesystemCredentialResolver unable to load private key from file.");
 456 }
 457
 458 // Used to determine the encoding format of credentials files
 459 // dynamically. Supports: PEM, DER, PKCS12.
 460 FilesystemCredentialResolver::format_t FilesystemCredentialResolver::getEncodingFormat(BIO* in) const
 461 {
 462     PKCS12* p12 = NULL;
 463     format_t format;
 464
 465     const int READSIZE = 1;
 466     char buf[READSIZE];
 467     char b1;
 468     int mark;
 469
 470     try {
 471         if ( (mark = BIO_tell(in)) < 0 )
 472             throw XMLSecurityException("getEncodingFormat: BIO_tell() can't get the file position");
 473         if ( BIO_read(in, buf, READSIZE) <= 0 )
 474             throw XMLSecurityException("getEncodingFormat: BIO_read() can't read from the stream");
 475         if ( BIO_seek(in, mark) < 0 )
 476             throw XMLSecurityException("getEncodingFormat: BIO_seek() can't reset the file position");
 477     }
 478     catch (...) {
 479         log_openssl();
 480         throw;
 481     }
 482
 483     b1 = buf[0];
 484
 485     // This is a slight variation of the Java code by Chad La Joie.
 486     //
 487     // Check the first byte of the file.  If it's some kind of
 488     // DER-encoded structure (including PKCS12), it will begin with ASCII 048.
 489     // Otherwise, assume it's PEM.
 490     if (b1 !=  48) {
 491         format = PEM;
 492     } else {
 493         // Here we know it's DER-encoded, now try to parse it as a PKCS12
 494         // ASN.1 structure.  If it fails, must be another kind of DER-encoded
 495         // key/cert structure.  A little inefficient...but it works.
 496         if ( (p12=d2i_PKCS12_bio(in,NULL)) == NULL ) {
 497             format = DER;
 498         } else {
 499             format = _PKCS12;
 500         }
 501         if (p12)
 502             PKCS12_free(p12);
 503         if ( BIO_seek(in, mark) < 0 ) {
 504             log_openssl();
 505             throw XMLSecurityException("getEncodingFormat: BIO_seek() can't reset the file position");
 506         }
 507     }
 508
 509     return format;
 510 }
 511
 512 // Convert key/cert format_t types to a human-meaningful string for debug output
 513 string FilesystemCredentialResolver::formatToString(format_t format) const
 514 {
 515     switch(format) {
 516         case PEM:
 517             return "PEM";
 518         case DER:
 519             return "DER";
 520         case _PKCS12:
 521             return "PKCS12";
 522         default:
 523             return "UNKNOWN";
 524     }
 525 }
 526
 527 // Convert key/cert raw XML format attribute (XMLCh[]) to format_t type
 528 FilesystemCredentialResolver::format_t FilesystemCredentialResolver::xmlFormatToFormat(const XMLCh* format_xml) const
 529 {
 530     static const XMLCh cPEM[] = UNICODE_LITERAL_3(P,E,M);
 531     static const XMLCh cDER[] = UNICODE_LITERAL_3(D,E,R);
 532     static const XMLCh cPKCS12[] = { chLatin_P, chLatin_K, chLatin_C, chLatin_S, chDigit_1, chDigit_2, chNull };
 533     format_t format;
 534
 535     if (!XMLString::compareString(format_xml,cPEM))
 536         format=PEM;
 537     else if (!XMLString::compareString(format_xml,cDER))
 538         format=DER;
 539     else if (!XMLString::compareString(format_xml,cPKCS12))
 540         format=_PKCS12;
 541     else
 542         format=UNKNOWN;
 543
 544     return format;
 545 }
 546
 547 void FilesystemCredentialResolver::attach(SSL_CTX* ctx) const
 548 {
 549 #ifdef _DEBUG
 550     NDC ndc("attach");
 551 #endif
 552
 553     if (m_keypath.empty())
 554         throw XMLSecurityException("No key available, unable to attach private key to SSL context.");
 555
 556     // Attach key.
 557     SSL_CTX_set_default_passwd_cb(ctx, passwd_callback);
 558     SSL_CTX_set_default_passwd_cb_userdata(ctx, const_cast<char*>(m_keypass.c_str()));
 559
 560     int ret=0;
 561     switch (m_keyformat) {
 562         case PEM:
 563             ret=SSL_CTX_use_PrivateKey_file(ctx, m_keypath.c_str(), m_keyformat);
 564             break;
 565
 566         case DER:
 567             ret=SSL_CTX_use_RSAPrivateKey_file(ctx, m_keypath.c_str(), m_keyformat);
 568             break;
 569
 570         default: {
 571             BIO* in=BIO_new(BIO_s_file_internal());
 572             if (in && BIO_read_filename(in,m_keypath.c_str())>0) {
 573                 EVP_PKEY* pkey=NULL;
 574                 PKCS12* p12 = d2i_PKCS12_bio(in, NULL);
 575                 if (p12) {
 576                     PKCS12_parse(p12, const_cast<char*>(m_keypass.c_str()), &pkey, NULL, NULL);
 577                     PKCS12_free(p12);
 578                     if (pkey) {
 579                         ret=SSL_CTX_use_PrivateKey(ctx, pkey);
 580                         EVP_PKEY_free(pkey);
 581                     }
 582                 }
 583             }
 584             if (in)
 585                 BIO_free(in);
 586         }
 587     }
 588
 589     if (ret!=1) {
 590         log_openssl();
 591         throw XMLSecurityException("Unable to attach private key to SSL context.");
 592     }
 593
 594     // Attach certs.
 595     for (vector<X509*>::const_iterator i=m_certs.begin(); i!=m_certs.end(); i++) {
 596         if (i==m_certs.begin()) {
 597             if (SSL_CTX_use_certificate(ctx, *i) != 1) {
 598                 log_openssl();
 599                 throw XMLSecurityException("Unable to attach client certificate to SSL context.");
 600             }
 601         }
 602         else {
 603             // When we add certs, they don't get ref counted, so we need to duplicate them.
 604             X509* dup = X509_dup(*i);
 605             if (SSL_CTX_add_extra_chain_cert(ctx, dup) != 1) {
 606                 X509_free(dup);
 607                 log_openssl();
 608                 throw XMLSecurityException("Unable to attach CA certificate to SSL context.");
 609             }
 610         }
 611     }
 612 }
 613
 614 void FilesystemCredential::addKeyNames(const DOMElement* e)
 615 {
 616     e = e ? XMLHelper::getFirstChildElement(e, Name) : NULL;
 617     while (e) {
 618         if (e->hasChildNodes()) {
 619             auto_ptr_char n(e->getFirstChild()->getNodeValue());
 620             if (n.get() && *n.get())
 621                 m_keyNames.insert(n.get());
 622         }
 623         e = XMLHelper::getNextSiblingElement(e, Name);
 624     }
 625 }
 626
 627 void FilesystemCredential::attach(SSL_CTX* ctx) const
 628 {
 629     return m_resolver->attach(ctx);
 630 }