xmltooling/soap/impl/CURLSOAPTransport.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  * CURLSOAPTransport.cpp
  19  *
  20  * libcurl-based SOAPTransport implementation
  21  */
  22
  23 #include "internal.h"
  24 #include "exceptions.h"
  25 #include "logging.h"
  26 #include "security/CredentialCriteria.h"
  27 #include "security/OpenSSLTrustEngine.h"
  28 #include "security/OpenSSLCredential.h"
  29 #include "soap/HTTPSOAPTransport.h"
  30 #include "soap/OpenSSLSOAPTransport.h"
  31 #include "util/NDC.h"
  32 #include "util/Threads.h"
  33
  34 #include <list>
  35 #include <curl/curl.h>
  36 #include <openssl/x509_vfy.h>
  37
  38 using namespace xmltooling::logging;
  39 using namespace xmltooling;
  40 using namespace std;
  41
  42 namespace xmltooling {
  43
  44     // Manages cache of socket connections via CURL handles.
  45     class XMLTOOL_DLLLOCAL CURLPool
  46     {
  47     public:
  48         CURLPool() : m_size(0), m_lock(Mutex::create()),
  49             m_log(Category::getInstance(XMLTOOLING_LOGCAT".SOAPTransport.CURLPool")) {}
  50         ~CURLPool();
  51
  52         CURL* get(const char* to, const char* endpoint);
  53         void put(const char* to, const char* endpoint, CURL* handle);
  54
  55     private:
  56         typedef map<string,vector<CURL*> > poolmap_t;
  57         poolmap_t m_bindingMap;
  58         list< vector<CURL*>* > m_pools;
  59         long m_size;
  60         Mutex* m_lock;
  61         Category& m_log;
  62     };
  63
  64     static XMLTOOL_DLLLOCAL CURLPool* g_CURLPool = NULL;
  65
  66     class XMLTOOL_DLLLOCAL CURLSOAPTransport : public HTTPSOAPTransport, public OpenSSLSOAPTransport
  67     {
  68     public:
  69         CURLSOAPTransport(const char* peerName, const char* endpoint)
  70                 : m_peerName(peerName ? peerName : ""), m_endpoint(endpoint), m_handle(NULL), m_headers(NULL),
  71 #ifndef XMLTOOLING_NO_XMLSEC
  72                     m_cred(NULL), m_trustEngine(NULL), m_peerResolver(NULL), m_mandatory(false),
  73 #endif
  74                     m_ssl_callback(NULL), m_ssl_userptr(NULL), m_chunked(true), m_secure(false) {
  75             m_handle = g_CURLPool->get(peerName, endpoint);
  76             curl_easy_setopt(m_handle,CURLOPT_URL,endpoint);
  77             curl_easy_setopt(m_handle,CURLOPT_CONNECTTIMEOUT,15);
  78             curl_easy_setopt(m_handle,CURLOPT_TIMEOUT,30);
  79             curl_easy_setopt(m_handle,CURLOPT_HTTPAUTH,0);
  80             curl_easy_setopt(m_handle,CURLOPT_USERPWD,NULL);
  81             curl_easy_setopt(m_handle,CURLOPT_SSL_VERIFYHOST,2);
  82             curl_easy_setopt(m_handle,CURLOPT_HEADERDATA,this);
  83             m_headers=curl_slist_append(m_headers,"Content-Type: text/xml");
  84         }
  85
  86         virtual ~CURLSOAPTransport() {
  87             curl_slist_free_all(m_headers);
  88             curl_easy_setopt(m_handle,CURLOPT_ERRORBUFFER,NULL);
  89             curl_easy_setopt(m_handle,CURLOPT_PRIVATE,m_secure ? "secure" : NULL); // Save off security "state".
  90             g_CURLPool->put(m_peerName.c_str(), m_endpoint.c_str(), m_handle);
  91         }
  92
  93         bool isConfidential() const {
  94             return m_endpoint.find("https")==0;
  95         }
  96
  97         bool setConnectTimeout(long timeout) {
  98             return (curl_easy_setopt(m_handle,CURLOPT_CONNECTTIMEOUT,timeout)==CURLE_OK);
  99         }
 100
 101         bool setTimeout(long timeout) {
 102             return (curl_easy_setopt(m_handle,CURLOPT_TIMEOUT,timeout)==CURLE_OK);
 103         }
 104
 105         bool setAuth(transport_auth_t authType, const char* username=NULL, const char* password=NULL);
 106
 107         bool setVerifyHost(bool verify) {
 108             return (curl_easy_setopt(m_handle,CURLOPT_SSL_VERIFYHOST,verify ? 2 : 0)==CURLE_OK);
 109         }
 110
 111 #ifndef XMLTOOLING_NO_XMLSEC
 112         bool setCredential(const Credential* cred=NULL) {
 113             const OpenSSLCredential* down = dynamic_cast<const OpenSSLCredential*>(cred);
 114             if (!down) {
 115                 m_cred = NULL;
 116                 return (cred==NULL);
 117             }
 118             m_cred = down;
 119             return true;
 120         }
 121
 122         bool setTrustEngine(
 123             const X509TrustEngine* trustEngine=NULL,
 124             const CredentialResolver* peerResolver=NULL,
 125             CredentialCriteria* criteria=NULL,
 126             bool mandatory=true
 127             ) {
 128             const OpenSSLTrustEngine* down = dynamic_cast<const OpenSSLTrustEngine*>(trustEngine);
 129             if (!down) {
 130                 m_trustEngine = NULL;
 131                 m_peerResolver = NULL;
 132                 m_criteria = NULL;
 133                 return (trustEngine==NULL);
 134             }
 135             m_trustEngine = down;
 136             m_peerResolver = peerResolver;
 137             m_criteria = criteria;
 138             m_mandatory = mandatory;
 139             return true;
 140         }
 141
 142 #endif
 143
 144         bool useChunkedEncoding(bool chunked=true) {
 145             m_chunked = chunked;
 146             return true;
 147         }
 148
 149         bool setProviderOption(const char* provider, void* option, void* value) {
 150             if (!provider || strcmp(provider, "CURL"))
 151                 return false;
 152             // For libcurl, the option is an enum and the value type depends on the option.
 153             CURLoption opt = static_cast<CURLoption>(reinterpret_cast<long>(option));
 154             if (opt < CURLOPTTYPE_OBJECTPOINT)
 155                 return (curl_easy_setopt(m_handle, opt, reinterpret_cast<long>(value))==CURLE_OK);
 156             else if (opt < CURLOPTTYPE_OFF_T)
 157                 return (curl_easy_setopt(m_handle, opt, value)==CURLE_OK);
 158             else if (sizeof(void*) == sizeof(curl_off_t))
 159                 return (curl_easy_setopt(m_handle, opt, reinterpret_cast<curl_off_t>(value))==CURLE_OK);
 160             return false;
 161         }
 162
 163         void send(istream& in);
 164
 165         istream& receive() {
 166             return m_stream;
 167         }
 168
 169         bool isSecure() const {
 170             return m_secure;
 171         }
 172
 173         void setSecure(bool secure) {
 174             m_secure = secure;
 175         }
 176
 177         string getContentType() const;
 178
 179         bool setRequestHeader(const char* name, const char* val) {
 180             string temp(name);
 181             temp=temp + ": " + val;
 182             m_headers=curl_slist_append(m_headers,temp.c_str());
 183             return true;
 184         }
 185
 186         const vector<string>& getResponseHeader(const char* val) const;
 187
 188         bool setSSLCallback(ssl_ctx_callback_fn fn, void* userptr=NULL) {
 189             m_ssl_callback=fn;
 190             m_ssl_userptr=userptr;
 191             return true;
 192         }
 193
 194     private:
 195         // per-call state
 196         string m_peerName,m_endpoint,m_simplecreds;
 197         CURL* m_handle;
 198         stringstream m_stream;
 199         struct curl_slist* m_headers;
 200         map<string,vector<string> > m_response_headers;
 201 #ifndef XMLTOOLING_NO_XMLSEC
 202         const OpenSSLCredential* m_cred;
 203         const OpenSSLTrustEngine* m_trustEngine;
 204         const CredentialResolver* m_peerResolver;
 205         CredentialCriteria* m_criteria;
 206         bool m_mandatory;
 207 #endif
 208         ssl_ctx_callback_fn m_ssl_callback;
 209         void* m_ssl_userptr;
 210         bool m_chunked;
 211         bool m_secure;
 212
 213         friend size_t XMLTOOL_DLLLOCAL curl_header_hook(void* ptr, size_t size, size_t nmemb, void* stream);
 214         friend CURLcode XMLTOOL_DLLLOCAL xml_ssl_ctx_callback(CURL* curl, SSL_CTX* ssl_ctx, void* userptr);
 215         friend int XMLTOOL_DLLLOCAL verify_callback(X509_STORE_CTX* x509_ctx, void* arg);
 216     };
 217
 218     // libcurl callback functions
 219     size_t XMLTOOL_DLLLOCAL curl_header_hook(void* ptr, size_t size, size_t nmemb, void* stream);
 220     size_t XMLTOOL_DLLLOCAL curl_write_hook(void* ptr, size_t size, size_t nmemb, void* stream);
 221     size_t XMLTOOL_DLLLOCAL curl_read_hook( void *ptr, size_t size, size_t nmemb, void *stream);
 222     int XMLTOOL_DLLLOCAL curl_debug_hook(CURL* handle, curl_infotype type, char* data, size_t len, void* ptr);
 223     CURLcode XMLTOOL_DLLLOCAL xml_ssl_ctx_callback(CURL* curl, SSL_CTX* ssl_ctx, void* userptr);
 224 #ifndef XMLTOOLING_NO_XMLSEC
 225     int XMLTOOL_DLLLOCAL verify_callback(X509_STORE_CTX* x509_ctx, void* arg);
 226 #endif
 227
 228     SOAPTransport* CURLSOAPTransportFactory(const pair<const char*,const char*>& dest)
 229     {
 230         return new CURLSOAPTransport(dest.first, dest.second);
 231     }
 232 };
 233
 234 void xmltooling::registerSOAPTransports()
 235 {
 236     XMLToolingConfig& conf=XMLToolingConfig::getConfig();
 237     conf.SOAPTransportManager.registerFactory("http", CURLSOAPTransportFactory);
 238     conf.SOAPTransportManager.registerFactory("https", CURLSOAPTransportFactory);
 239 }
 240
 241 void xmltooling::initSOAPTransports()
 242 {
 243     g_CURLPool=new CURLPool();
 244 }
 245
 246 void xmltooling::termSOAPTransports()
 247 {
 248     delete g_CURLPool;
 249     g_CURLPool = NULL;
 250 }
 251
 252 CURLPool::~CURLPool()
 253 {
 254     for (poolmap_t::iterator i=m_bindingMap.begin(); i!=m_bindingMap.end(); i++) {
 255         for (vector<CURL*>::iterator j=i->second.begin(); j!=i->second.end(); j++)
 256             curl_easy_cleanup(*j);
 257     }
 258     delete m_lock;
 259 }
 260
 261 CURL* CURLPool::get(const char* to, const char* endpoint)
 262 {
 263 #ifdef _DEBUG
 264     xmltooling::NDC("get");
 265 #endif
 266     m_log.debug("getting connection handle to %s", endpoint);
 267     m_lock->lock();
 268     poolmap_t::iterator i=m_bindingMap.find(string(to) + "|" + endpoint);
 269
 270     if (i!=m_bindingMap.end()) {
 271         // Move this pool to the front of the list.
 272         m_pools.remove(&(i->second));
 273         m_pools.push_front(&(i->second));
 274
 275         // If a free connection exists, return it.
 276         if (!(i->second.empty())) {
 277             CURL* handle=i->second.back();
 278             i->second.pop_back();
 279             m_size--;
 280             m_lock->unlock();
 281             m_log.debug("returning existing connection handle from pool");
 282             return handle;
 283         }
 284     }
 285
 286     m_lock->unlock();
 287     m_log.debug("nothing free in pool, returning new connection handle");
 288
 289     // Create a new connection and set non-varying options.
 290     CURL* handle=curl_easy_init();
 291     if (!handle)
 292         return NULL;
 293     curl_easy_setopt(handle,CURLOPT_NOPROGRESS,1);
 294     curl_easy_setopt(handle,CURLOPT_NOSIGNAL,1);
 295     curl_easy_setopt(handle,CURLOPT_FAILONERROR,1);
 296     curl_easy_setopt(handle,CURLOPT_SSLVERSION,3);
 297     // Verification of the peer is via TrustEngine only.
 298     curl_easy_setopt(handle,CURLOPT_SSL_VERIFYPEER,0);
 299     curl_easy_setopt(handle,CURLOPT_HEADERFUNCTION,&curl_header_hook);
 300     curl_easy_setopt(handle,CURLOPT_WRITEFUNCTION,&curl_write_hook);
 301     curl_easy_setopt(handle,CURLOPT_DEBUGFUNCTION,&curl_debug_hook);
 302
 303     return handle;
 304 }
 305
 306 void CURLPool::put(const char* to, const char* endpoint, CURL* handle)
 307 {
 308     string key = string(to) + "|" + endpoint;
 309     m_lock->lock();
 310     poolmap_t::iterator i=m_bindingMap.find(key);
 311     if (i==m_bindingMap.end())
 312         m_pools.push_front(&(m_bindingMap.insert(poolmap_t::value_type(key,vector<CURL*>(1,handle))).first->second));
 313     else
 314         i->second.push_back(handle);
 315
 316     CURL* killit=NULL;
 317     if (++m_size > 256) {
 318         // Kick a handle out from the back of the bus.
 319         while (true) {
 320             vector<CURL*>* corpse=m_pools.back();
 321             if (!corpse->empty()) {
 322                 killit=corpse->back();
 323                 corpse->pop_back();
 324                 m_size--;
 325                 break;
 326             }
 327
 328             // Move an empty pool up to the front so we don't keep hitting it.
 329             m_pools.pop_back();
 330             m_pools.push_front(corpse);
 331         }
 332     }
 333     m_lock->unlock();
 334     if (killit) {
 335         curl_easy_cleanup(killit);
 336 #ifdef _DEBUG
 337         xmltooling::NDC("put");
 338 #endif
 339         m_log.info("conn_pool_max limit reached, dropping an old connection");
 340     }
 341 }
 342
 343 bool CURLSOAPTransport::setAuth(transport_auth_t authType, const char* username, const char* password)
 344 {
 345     if (authType==transport_auth_none) {
 346         if (curl_easy_setopt(m_handle,CURLOPT_HTTPAUTH,0)!=CURLE_OK)
 347             return false;
 348         return (curl_easy_setopt(m_handle,CURLOPT_USERPWD,NULL)==CURLE_OK);
 349     }
 350     long flag=0;
 351     switch (authType) {
 352         case transport_auth_basic:    flag = CURLAUTH_BASIC; break;
 353         case transport_auth_digest:   flag = CURLAUTH_DIGEST; break;
 354         case transport_auth_ntlm:     flag = CURLAUTH_NTLM; break;
 355         case transport_auth_gss:      flag = CURLAUTH_GSSNEGOTIATE; break;
 356         default:            return false;
 357     }
 358     if (curl_easy_setopt(m_handle,CURLOPT_HTTPAUTH,flag)!=CURLE_OK)
 359         return false;
 360     m_simplecreds = string(username ? username : "") + ':' + (password ? password : "");
 361     return (curl_easy_setopt(m_handle,CURLOPT_USERPWD,m_simplecreds.c_str())==CURLE_OK);
 362 }
 363
 364 const vector<string>& CURLSOAPTransport::getResponseHeader(const char* name) const
 365 {
 366     static vector<string> emptyVector;
 367
 368     map<string,vector<string> >::const_iterator i=m_response_headers.find(name);
 369     if (i!=m_response_headers.end())
 370         return i->second;
 371
 372     for (map<string,vector<string> >::const_iterator j=m_response_headers.begin(); j!=m_response_headers.end(); j++) {
 373 #ifdef HAVE_STRCASECMP
 374         if (!strcasecmp(j->first.c_str(), name))
 375 #else
 376         if (!stricmp(j->first.c_str(), name))
 377 #endif
 378             return j->second;
 379     }
 380
 381     return emptyVector;
 382 }
 383
 384 string CURLSOAPTransport::getContentType() const
 385 {
 386     char* content_type=NULL;
 387     curl_easy_getinfo(m_handle,CURLINFO_CONTENT_TYPE,&content_type);
 388     return content_type ? content_type : "";
 389 }
 390
 391 void CURLSOAPTransport::send(istream& in)
 392 {
 393 #ifdef _DEBUG
 394     xmltooling::NDC ndc("send");
 395 #endif
 396     Category& log=Category::getInstance(XMLTOOLING_LOGCAT".SOAPTransport");
 397     Category& log_curl=Category::getInstance(XMLTOOLING_LOGCAT".libcurl");
 398
 399     string msg;
 400
 401     // By this time, the handle has been prepared with the URL to use and the
 402     // caller should have executed any set functions to manipulate it.
 403
 404     // Setup standard per-call curl properties.
 405     curl_easy_setopt(m_handle,CURLOPT_DEBUGDATA,&log_curl);
 406     curl_easy_setopt(m_handle,CURLOPT_FILE,&m_stream);
 407     curl_easy_setopt(m_handle,CURLOPT_POST,1);
 408     if (m_chunked) {
 409         m_headers=curl_slist_append(m_headers,"Transfer-Encoding: chunked");
 410         curl_easy_setopt(m_handle,CURLOPT_READFUNCTION,&curl_read_hook);
 411         curl_easy_setopt(m_handle,CURLOPT_READDATA,&in);
 412     }
 413     else {
 414         char buf[1024];
 415         while (in) {
 416             in.read(buf,1024);
 417             msg.append(buf,in.gcount());
 418         }
 419         curl_easy_setopt(m_handle,CURLOPT_READFUNCTION,NULL);
 420         curl_easy_setopt(m_handle,CURLOPT_POSTFIELDS,msg.c_str());
 421         curl_easy_setopt(m_handle,CURLOPT_POSTFIELDSIZE,msg.length());
 422     }
 423
 424     char curl_errorbuf[CURL_ERROR_SIZE];
 425     curl_errorbuf[0]=0;
 426     curl_easy_setopt(m_handle,CURLOPT_ERRORBUFFER,curl_errorbuf);
 427     if (log_curl.isDebugEnabled())
 428         curl_easy_setopt(m_handle,CURLOPT_VERBOSE,1);
 429
 430     // Set request headers.
 431     curl_easy_setopt(m_handle,CURLOPT_HTTPHEADER,m_headers);
 432
 433 #ifndef XMLTOOLING_NO_XMLSEC
 434     if (m_ssl_callback || m_cred || m_trustEngine) {
 435 #else
 436     if (m_ssl_callback) {
 437 #endif
 438         curl_easy_setopt(m_handle,CURLOPT_SSL_CTX_FUNCTION,xml_ssl_ctx_callback);
 439         curl_easy_setopt(m_handle,CURLOPT_SSL_CTX_DATA,this);
 440
 441         // Restore security "state". Necessary because the callback only runs
 442         // when handshakes occur. Even new TCP connections won't execute it.
 443         char* priv=NULL;
 444         curl_easy_getinfo(m_handle,CURLINFO_PRIVATE,&priv);
 445         if (priv)
 446             m_secure=true;
 447     }
 448     else {
 449         curl_easy_setopt(m_handle,CURLOPT_SSL_CTX_FUNCTION,NULL);
 450         curl_easy_setopt(m_handle,CURLOPT_SSL_CTX_DATA,NULL);
 451     }
 452
 453     // Make the call.
 454     log.debug("sending SOAP message to %s", m_endpoint.c_str());
 455     if (curl_easy_perform(m_handle) != CURLE_OK) {
 456         throw IOException(
 457             string("CURLSOAPTransport failed while contacting SOAP responder: ") +
 458                 (curl_errorbuf[0] ? curl_errorbuf : "no further information available"));
 459     }
 460 }
 461
 462 // callback to buffer headers from server
 463 size_t xmltooling::curl_header_hook(void* ptr, size_t size, size_t nmemb, void* stream)
 464 {
 465     // only handle single-byte data
 466     if (size!=1)
 467         return 0;
 468     CURLSOAPTransport* ctx = reinterpret_cast<CURLSOAPTransport*>(stream);
 469     char* buf = (char*)malloc(nmemb + 1);
 470     if (buf) {
 471         memset(buf,0,nmemb + 1);
 472         memcpy(buf,ptr,nmemb);
 473         char* sep=(char*)strchr(buf,':');
 474         if (sep) {
 475             *(sep++)=0;
 476             while (*sep==' ')
 477                 *(sep++)=0;
 478             char* white=buf+nmemb-1;
 479             while (isspace(*white))
 480                 *(white--)=0;
 481             ctx->m_response_headers[buf].push_back(sep);
 482         }
 483         free(buf);
 484         return nmemb;
 485     }
 486     return 0;
 487 }
 488
 489 // callback to send data to server
 490 size_t xmltooling::curl_read_hook(void* ptr, size_t size, size_t nmemb, void* stream)
 491 {
 492     // *stream is actually an istream object
 493     istream& buf=*(reinterpret_cast<istream*>(stream));
 494     buf.read(reinterpret_cast<char*>(ptr),size*nmemb);
 495     return buf.gcount();
 496 }
 497
 498 // callback to buffer data from server
 499 size_t xmltooling::curl_write_hook(void* ptr, size_t size, size_t nmemb, void* stream)
 500 {
 501     size_t len = size*nmemb;
 502     reinterpret_cast<stringstream*>(stream)->write(reinterpret_cast<const char*>(ptr),len);
 503     return len;
 504 }
 505
 506 // callback for curl debug data
 507 int xmltooling::curl_debug_hook(CURL* handle, curl_infotype type, char* data, size_t len, void* ptr)
 508 {
 509     // *ptr is actually a logging object
 510     if (!ptr) return 0;
 511     CategoryStream log=reinterpret_cast<Category*>(ptr)->debugStream();
 512     for (unsigned char* ch=(unsigned char*)data; len && (isprint(*ch) || isspace(*ch)); len--)
 513         log << *ch++;
 514     return 0;
 515 }
 516
 517 #ifndef XMLTOOLING_NO_XMLSEC
 518 int xmltooling::verify_callback(X509_STORE_CTX* x509_ctx, void* arg)
 519 {
 520     Category& log = Category::getInstance("OpenSSL");
 521     log.debug("invoking X509 verify callback");
 522 #if (OPENSSL_VERSION_NUMBER >= 0x00907000L)
 523     CURLSOAPTransport* ctx = reinterpret_cast<CURLSOAPTransport*>(arg);
 524 #else
 525     // Yes, this sucks. I'd use TLS, but there's no really obvious spot to put the thread key
 526     // and global variables suck too. We can't access the X509_STORE_CTX depth directly because
 527     // OpenSSL only copies it into the context if it's >=0, and the unsigned pointer may be
 528     // negative in the SSL structure's int member.
 529     CURLSOAPTransport* ctx = reinterpret_cast<CURLSOAPTransport*>(
 530         SSL_get_verify_depth(
 531             reinterpret_cast<SSL*>(X509_STORE_CTX_get_ex_data(x509_ctx,SSL_get_ex_data_X509_STORE_CTX_idx()))
 532             )
 533         );
 534 #endif
 535
 536     bool success=false;
 537     if (ctx->m_criteria) {
 538         ctx->m_criteria->setUsage(CredentialCriteria::TLS_CREDENTIAL);
 539         // Bypass name check (handled for us by curl).
 540         ctx->m_criteria->setPeerName(NULL);
 541         success = ctx->m_trustEngine->validate(x509_ctx->cert,x509_ctx->untrusted,*(ctx->m_peerResolver),ctx->m_criteria);
 542     }
 543     else {
 544         // Bypass name check (handled for us by curl).
 545         CredentialCriteria cc;
 546         cc.setUsage(CredentialCriteria::TLS_CREDENTIAL);
 547         success = ctx->m_trustEngine->validate(x509_ctx->cert,x509_ctx->untrusted,*(ctx->m_peerResolver),&cc);
 548     }
 549
 550     if (!success) {
 551         log.error("supplied TrustEngine failed to validate SSL/TLS server certificate");
 552         x509_ctx->error=X509_V_ERR_APPLICATION_VERIFICATION;     // generic error, check log for plugin specifics
 553         ctx->setSecure(false);
 554         return ctx->m_mandatory ? 0 : 1;
 555     }
 556
 557     // Signal success. Hopefully it doesn't matter what's actually in the structure now.
 558     ctx->setSecure(true);
 559     return 1;
 560 }
 561 #endif
 562
 563 // callback to invoke a caller-defined SSL callback
 564 CURLcode xmltooling::xml_ssl_ctx_callback(CURL* curl, SSL_CTX* ssl_ctx, void* userptr)
 565 {
 566     CURLSOAPTransport* conf = reinterpret_cast<CURLSOAPTransport*>(userptr);
 567
 568 #ifndef XMLTOOLING_NO_XMLSEC
 569     if (conf->m_cred)
 570         conf->m_cred->attach(ssl_ctx);
 571
 572     if (conf->m_trustEngine) {
 573         SSL_CTX_set_verify(ssl_ctx,SSL_VERIFY_PEER,NULL);
 574 #if (OPENSSL_VERSION_NUMBER >= 0x00907000L)
 575         // With 0.9.7, we can pass a callback argument directly.
 576         SSL_CTX_set_cert_verify_callback(ssl_ctx,verify_callback,userptr);
 577 #else
 578         // With 0.9.6, there's no argument, so we're going to use a really embarrassing hack and
 579         // stuff the argument in the depth property where it will get copied to the context object
 580         // that's handed to the callback.
 581         SSL_CTX_set_cert_verify_callback(ssl_ctx,reinterpret_cast<int (*)()>(verify_callback),NULL);
 582         SSL_CTX_set_verify_depth(ssl_ctx,reinterpret_cast<int>(userptr));
 583 #endif
 584     }
 585 #endif
 586
 587     if (conf->m_ssl_callback && !conf->m_ssl_callback(conf, ssl_ctx, conf->m_ssl_userptr))
 588         return CURLE_SSL_CERTPROBLEM;
 589
 590     return CURLE_OK;
 591 }