added more precise source tree version detection

Signed-off-by: Michael Krelin <hacker@klever.net>

2 files changed, 12 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index 50dd8d4..23e40da 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,97 +1,108 @@
 AC_INIT([libopkele], [0.3], [libopkele-bugs@klever.net])
 AC_CONFIG_SRCDIR([include/opkele/opkele-config.h])
 AC_CONFIG_HEADERS([config.h include/opkele/acconfig.h])
 AM_INIT_AUTOMAKE([dist-bzip2])
 
 AC_PROG_INSTALL
 AC_PROG_CXX
 AC_PROG_CC
 AC_PROG_LIBTOOL
 PKG_PROG_PKG_CONFIG
 
 AC_HEADER_STDC
 
 AC_PATH_PROG([XSLTPROC],[xsltproc],[true])
 
+AC_MSG_CHECKING([for source tree version])
+if headrev=$(cd $srcdir && git rev-parse --verify HEAD 2>/dev/null) ; then
+ PACKAGE_SRC_VERSION="${PACKAGE_VERSION}:$(cd $srcdir && git describe --tags $headrev)"
+ ( cd $srcdir && git diff-index $headrev | read dirt ) && PACKAGE_SRC_VERSION="${PACKAGE_SRC_VERSION}-dirty"
+else
+ PACKAGE_SRC_VERSION="$PACKAGE_VERSION"
+fi
+AC_MSG_RESULT([$PACKAGE_SRC_VERSION])
+AC_SUBST([PACKAGE_SRC_VERSION])
+AC_DEFINE_UNQUOTED([PACKAGE_SRC_VERSION],["$PACKAGE_SRC_VERSION"],[more or less precise source tree version])
+
 PKG_CHECK_MODULES([OPENSSL],[openssl],,[
  AC_MSG_ERROR([no openssl library found. get one from http://www.openssl.org/])
 ])
 
 WANT_KONFORKA="yes"
 AC_ARG_ENABLE([konforka],
  AC_HELP_STRING([--disable-konforka],[do not use konforka library (default: use if found)]),
  [
   test "${enableval}" = "no" && WANT_KONFORKA="no"
  ]
 )
 if test "${WANT_KONFORKA}" = "yes" ; then
  PKG_CHECK_MODULES([KONFORKA],[konforka],[
   AC_SUBST([KONFORKA_CFLAGS])
   AC_SUBST([KONFORKA_LIBS])
   AC_DEFINE([HAVE_KONFORKA],,[defined in presence of konforka library])
   AC_DEFINE([OPKELE_HAVE_KONFORKA],,[defined in presence of konforka library])
   AC_SUBST([KONFORKA_KONFORKA],[konforka])
  ],[true])
 fi
 
 WANT_DOXYGEN="yes"
 AC_ARG_ENABLE([doxygen],
  AC_HELP_STRING([--disable-doxygen],[do not generate documentation]),
  [
   test "${enableval}" = "no" && WANT_DOXYGEN="no"
  ]
 )
 if test "${WANT_DOXYGEN}" = "yes" ; then
  AC_WITH_DOXYGEN
  AC_WITH_DOT
 else
  AM_CONDITIONAL([HAVE_DOXYGEN],[false])
  AM_CONDITIONAL([HAVE_DOT],[false])
 fi
 
 LIBCURL_CHECK_CONFIG(,,,[
  AC_MSG_ERROR([no required libcurl library. get one from http://curl.haxx.se/])
 ])
 
 if test -n "$PCRE_LIBS" -a -n "$PCRE_CFLAGS" ; then
  AC_SUBST([PCRE_CFLAGS])
  AC_SUBST([PCRE_LIBS])
  :
 else
  PKG_CHECK_MODULES([PCRE],[libpcre],,[
   AC_MSG_ERROR([no libpcre found, go get it at http://www.pcre.org/])
  ])
 fi
 
 curl_ssl_verify_host="true"
 AC_ARG_ENABLE([ssl-verify-host],
  AC_HELP_STRING([--disable-ssl-verify-host],[disable cURL cert/host relationships verification]),
  [ test "${enableval}" = "no" && curl_ssl_verify_host="false" ]
 )
 ${curl_ssl_verify_host} || AC_DEFINE([DISABLE_CURL_SSL_VERIFYHOST],,[defined if cURL is not to verify cert/host])
 
 curl_ssl_verify_peer="true"
 AC_ARG_ENABLE([ssl-verify-peer],
  AC_HELP_STRING([--disable-ssl-verify-peer],[disable cURL cert validity verification]),
  [ test "${enableval}" = "no" && curl_ssl_verify_peer="false" ]
 )
 ${curl_ssl_verify_peer} || AC_DEFINE([DISABLE_CURL_SSL_VERIFYPEER],,[defined if cURL is not to verify cert validity])
 
 postels_law=true
 AC_ARG_ENABLE([postels-law],
  AC_HELP_STRING([--disable-postels-law],[Be strict, do not adhere to Postel's Law ("be conservative in what you do, be liberal in what you accept from others", RFC 793)]),
  [ test "${enableval}" = "no" && postels_law=false ]
 )
 $postels_law && AC_DEFINE([POSTELS_LAW],,[defined if we want to adhere to Postel's Law])
 
 AC_DEFINE_UNQUOTED([OPKELE_SRC_DIR],["$PWD"],[source directory])
 
 AC_CONFIG_FILES([
  Makefile
   libopkele.pc
   Doxyfile
  include/Makefile
  lib/Makefile
  test/Makefile
 ])
 AC_OUTPUT
diff --git a/lib/consumer.cc b/lib/consumer.cc
index f72ae08..76b6ea7 100644
--- a/lib/consumer.cc
+++ b/lib/consumer.cc
@@ -1,439 +1,439 @@
 #include <algorithm>
 #include <cassert>
 #include <opkele/util.h>
 #include <opkele/exception.h>
 #include <opkele/data.h>
 #include <opkele/consumer.h>
 #include <openssl/sha.h>
 #include <openssl/hmac.h>
 #include <curl/curl.h>
 
 #include <iostream>
 
 #include "config.h"
 
 #include <pcre.h>
 
 namespace opkele {
     using namespace std;
 
     class pcre_matches_t {
 	public:
 	    int *_ov;
 	    int _s;
 
 	    pcre_matches_t() : _ov(0), _s(0) { }
 	    pcre_matches_t(int s) : _ov(0), _s(s) {
 		if(_s&1) ++_s;
 		_s += _s>>1;
 		_ov = new int[_s];
 	    }
 	    ~pcre_matches_t() throw() { if(_ov) delete[] _ov; }
 
 	    int begin(int i) const { return _ov[i<<1]; }
 	    int end(int i) const { return _ov[(i<<1)+1]; }
 	    int length(int i) const { int t=i<<1; return _ov[t+1]-_ov[t]; }
     };
 
     class pcre_t {
 	public:
 	    pcre *_p;
 
 	    pcre_t() : _p(0) { }
 	    pcre_t(pcre *p) : _p(p) { }
 	    pcre_t(const char *re,int opts) : _p(0) {
 		static const char *errptr; static int erroffset;
 		_p = pcre_compile(re,opts,&errptr,&erroffset,NULL);
 		if(!_p)
 		    throw internal_error(OPKELE_CP_ string("Failed to compile regexp: ")+errptr);
 	    }
 	    ~pcre_t() throw() { if(_p) (*pcre_free)(_p); }
 
 	    pcre_t& operator=(pcre *p) { if(_p) (*pcre_free)(_p); _p=p; return *this; }
 
 	    operator const pcre*(void) const { return _p; }
 	    operator pcre*(void) { return _p; }
 
 	    int exec(const string& s,pcre_matches_t& m) {
 		if(!_p)
 		    throw internal_error(OPKELE_CP_ "Trying to execute absent regexp");
 		return pcre_exec(_p,NULL,s.c_str(),s.length(),0,0,m._ov,m._s);
 	    }
     };
 
     class curl_t {
 	public:
 	    CURL *_c;
 
 	    curl_t() : _c(0) { }
 	    curl_t(CURL *c) : _c(c) { }
 	    ~curl_t() throw() { if(_c) curl_easy_cleanup(_c); }
 
 	    curl_t& operator=(CURL *c) { if(_c) curl_easy_cleanup(_c); _c=c; return *this; }
 
 	    operator const CURL*(void) const { return _c; }
 	    operator CURL*(void) { return _c; }
     };
 
     static CURLcode curl_misc_sets(CURL* c) {
 	CURLcode r;
 	(r=curl_easy_setopt(c,CURLOPT_FOLLOWLOCATION,1))
 	|| (r=curl_easy_setopt(c,CURLOPT_MAXREDIRS,5))
 	|| (r=curl_easy_setopt(c,CURLOPT_DNS_CACHE_TIMEOUT,120))
 	|| (r=curl_easy_setopt(c,CURLOPT_DNS_USE_GLOBAL_CACHE,1))
-	|| (r=curl_easy_setopt(c,CURLOPT_USERAGENT,PACKAGE_NAME"/"PACKAGE_VERSION))
+	|| (r=curl_easy_setopt(c,CURLOPT_USERAGENT,PACKAGE_NAME"/"PACKAGE_SRC_VERSION))
 	|| (r=curl_easy_setopt(c,CURLOPT_TIMEOUT,20))
 #ifdef	DISABLE_CURL_SSL_VERIFYHOST
 	|| (r=curl_easy_setopt(c,CURLOPT_SSL_VERIFYHOST,0))
 #endif
 #ifdef	DISABLE_CURL_SSL_VERIFYPEER
 	|| (r=curl_easy_setopt(c,CURLOPT_SSL_VERIFYPEER,0))
 #endif
 	;
 	return r;
     }
 
     static size_t _curl_tostring(void *ptr,size_t size,size_t nmemb,void *stream) {
 	string *str = (string*)stream;
 	size_t bytes = size*nmemb;
 	size_t get = min(16384-str->length(),bytes);
 	str->append((const char*)ptr,get);
 	return get;
     }
 
     assoc_t consumer_t::associate(const string& server) {
 	util::dh_t dh = DH_new();
 	if(!dh)
 	    throw exception_openssl(OPKELE_CP_ "failed to DH_new()");
 	dh->p = util::dec_to_bignum(data::_default_p);
 	dh->g = util::dec_to_bignum(data::_default_g);
 	if(!DH_generate_key(dh))
 	    throw exception_openssl(OPKELE_CP_ "failed to DH_generate_key()");
 	string request = 
 	    "openid.mode=associate"
 	    "&openid.assoc_type=HMAC-SHA1"
 	    "&openid.session_type=DH-SHA1"
 	    "&openid.dh_consumer_public=";
 	request += util::url_encode(util::bignum_to_base64(dh->pub_key));
 	curl_t curl = curl_easy_init();
 	if(!curl)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_init()");
 	string response;
 	CURLcode r;
 	(r=curl_misc_sets(curl))
 	|| (r=curl_easy_setopt(curl,CURLOPT_URL,server.c_str()))
 	|| (r=curl_easy_setopt(curl,CURLOPT_POST,1))
 	|| (r=curl_easy_setopt(curl,CURLOPT_POSTFIELDS,request.data()))
 	|| (r=curl_easy_setopt(curl,CURLOPT_POSTFIELDSIZE,request.length()))
 	|| (r=curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,_curl_tostring))
 	|| (r=curl_easy_setopt(curl,CURLOPT_WRITEDATA,&response))
 	;
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_setopt()",r);
 	if(r=curl_easy_perform(curl))
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_perform()",r);
 	params_t p; p.parse_keyvalues(response);
 	if(p.has_param("assoc_type") && p.get_param("assoc_type")!="HMAC-SHA1")
 	    throw bad_input(OPKELE_CP_ "unsupported assoc_type");
 	string st;
 	if(p.has_param("session_type")) st = p.get_param("session_type");
 	if((!st.empty()) && st!="DH-SHA1")
 	    throw bad_input(OPKELE_CP_ "unsupported session_type");
 	secret_t secret;
 	if(st.empty()) {
 	    secret.from_base64(p.get_param("mac_key"));
 	}else{
 	    util::bignum_t s_pub = util::base64_to_bignum(p.get_param("dh_server_public"));
 	    vector<unsigned char> ck(DH_size(dh)+1);
 	    unsigned char *ckptr = &(ck.front())+1;
 	    int cklen = DH_compute_key(ckptr,s_pub,dh);
 	    if(cklen<0)
 		throw exception_openssl(OPKELE_CP_ "failed to DH_compute_key()");
 	    if(cklen && (*ckptr)&0x80) {
 		(*(--ckptr)) = 0; ++cklen;
 	    }
 	    unsigned char key_sha1[SHA_DIGEST_LENGTH];
 	    SHA1(ckptr,cklen,key_sha1);
 	    secret.enxor_from_base64(key_sha1,p.get_param("enc_mac_key"));
 	}
 	int expires_in = 0;
 	if(p.has_param("expires_in")) {
 	    expires_in = util::string_to_long(p.get_param("expires_in"));
 	}else if(p.has_param("issued") && p.has_param("expiry")) {
 	    expires_in = util::w3c_to_time(p.get_param("expiry"))-util::w3c_to_time(p.get_param("issued"));
 	}else
 	    throw bad_input(OPKELE_CP_ "no expiration information");
 	return store_assoc(server,p.get_param("assoc_handle"),secret,expires_in);
     }
 
     string consumer_t::checkid_immediate(const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
 	return checkid_(mode_checkid_immediate,identity,return_to,trust_root,ext);
     }
     string consumer_t::checkid_setup(const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
 	return checkid_(mode_checkid_setup,identity,return_to,trust_root,ext);
     }
     string consumer_t::checkid_(mode_t mode,const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
 	params_t p;
 	if(mode==mode_checkid_immediate)
 	    p["mode"]="checkid_immediate";
 	else if(mode==mode_checkid_setup)
 	    p["mode"]="checkid_setup";
 	else
 	    throw bad_input(OPKELE_CP_ "unknown checkid_* mode");
 	string iurl = canonicalize(identity);
 	string server, delegate;
 	retrieve_links(iurl,server,delegate);
 	p["identity"] = delegate.empty()?iurl:delegate;
 	if(!trust_root.empty())
 	    p["trust_root"] = trust_root;
 	p["return_to"] = return_to;
 	try {
 	    string ah = find_assoc(server)->handle();
 	    p["assoc_handle"] = ah;
 	}catch(failed_lookup& fl) {
 	    string ah = associate(server)->handle();
 	    p["assoc_handle"] = ah;
 	}
 	if(ext) ext->checkid_hook(p,identity);
 	return p.append_query(server);
     }
 
     void consumer_t::id_res(const params_t& pin,const string& identity,extension_t *ext) {
 	if(pin.has_param("openid.user_setup_url"))
 	    throw id_res_setup(OPKELE_CP_ "assertion failed, setup url provided",pin.get_param("openid.user_setup_url"));
 	string server,delegate;
 	retrieve_links(identity.empty()?pin.get_param("openid.identity"):canonicalize(identity),server,delegate);
 	params_t ps;
 	try {
 	    assoc_t assoc = retrieve_assoc(server,pin.get_param("openid.assoc_handle"));
 	    if(assoc->is_expired()) /* TODO: or should I throw some other exception to force programmer fix his implementation? */
 		throw failed_lookup(OPKELE_CP_ "retrieve_assoc() has returned expired handle");
 	    const string& sigenc = pin.get_param("openid.sig");
 	    vector<unsigned char> sig;
 	    util::decode_base64(sigenc,sig);
 	    const string& slist = pin.get_param("openid.signed");
 	    string kv;
 	    string::size_type p = 0;
 	    while(true) {
 		string::size_type co = slist.find(',',p);
 		string f = (co==string::npos)?slist.substr(p):slist.substr(p,co-p);
 		kv += f;
 		kv += ':';
 		f.insert(0,"openid.");
 		kv += pin.get_param(f);
 		kv += '\n';
 		if(ext) ps[f.substr(sizeof("openid.")-1)] = pin.get_param(f);
 		if(co==string::npos)
 		    break;
 		p = co+1;
 	    }
 	    secret_t secret = assoc->secret();
 	    unsigned int md_len = 0;
 	    unsigned char *md = HMAC(
 		    EVP_sha1(),
 		    &(secret.front()),secret.size(),
 		    (const unsigned char *)kv.data(),kv.length(),
 		    0,&md_len);
 	    if(sig.size()!=md_len || memcmp(&(sig.front()),md,md_len))
 		throw id_res_mismatch(OPKELE_CP_ "signature mismatch");
 	}catch(failed_lookup& e) { /* XXX: more specific? */
 	    const string& slist = pin.get_param("openid.signed");
 	    string::size_type pp = 0;
 	    params_t p;
 	    while(true) {
 		string::size_type co = slist.find(',',pp);
 		string f = "openid.";
 		f += (co==string::npos)?slist.substr(pp):slist.substr(pp,co-pp);
 		p[f] = pin.get_param(f);
 		if(co==string::npos)
 		    break;
 		pp = co+1;
 	    }
 	    p["openid.assoc_handle"] = pin.get_param("openid.assoc_handle");
 	    p["openid.sig"] = pin.get_param("openid.sig");
 	    p["openid.signed"] = pin.get_param("openid.signed");
 	    try {
 		string ih = pin.get_param("openid.invalidate_handle");
 		p["openid.invalidate_handle"] = ih;
 	    }catch(failed_lookup& fl) { }
 	    try {
 		check_authentication(server,p);
 	    }catch(failed_check_authentication& fca) {
 		throw id_res_failed(OPKELE_CP_ "failed to check_authentication()");
 	    }
 	}
 	if(ext) ext->id_res_hook(pin,ps,identity);
     }
 
     void consumer_t::check_authentication(const string& server,const params_t& p) {
 	string request = "openid.mode=check_authentication";
 	for(params_t::const_iterator i=p.begin();i!=p.end();++i) {
 	    if(i->first!="openid.mode") {
 		request += '&';
 		request += i->first;
 		request += '=';
 		request += util::url_encode(i->second);
 	    }
 	}
 	curl_t curl = curl_easy_init();
 	if(!curl)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_init()");
 	string response;
 	CURLcode r;
 	(r=curl_misc_sets(curl))
 	|| (r=curl_easy_setopt(curl,CURLOPT_URL,server.c_str()))
 	|| (r=curl_easy_setopt(curl,CURLOPT_POST,1))
 	|| (r=curl_easy_setopt(curl,CURLOPT_POSTFIELDS,request.data()))
 	|| (r=curl_easy_setopt(curl,CURLOPT_POSTFIELDSIZE,request.length()))
 	|| (r=curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,_curl_tostring))
 	|| (r=curl_easy_setopt(curl,CURLOPT_WRITEDATA,&response))
 	;
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_setopt()",r);
 	if(r=curl_easy_perform(curl))
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_perform()",r);
 	params_t pp; pp.parse_keyvalues(response);
 	if(pp.has_param("invalidate_handle"))
 	    invalidate_assoc(server,pp.get_param("invalidate_handle"));
 	if(pp.has_param("is_valid")) {
 	    if(pp.get_param("is_valid")=="true")
 		return;
 	}else if(pp.has_param("lifetime")) {
 	    if(util::string_to_long(pp.get_param("lifetime")))
 		return;
 	}
 	throw failed_check_authentication(OPKELE_CP_ "failed to verify response");
     }
 
     void consumer_t::retrieve_links(const string& url,string& server,string& delegate) {
 	server.erase();
 	delegate.erase();
 	curl_t curl = curl_easy_init();
 	if(!curl)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_init()");
 	string html;
 	CURLcode r;
 	(r=curl_misc_sets(curl))
 	|| (r=curl_easy_setopt(curl,CURLOPT_URL,url.c_str()))
 	|| (r=curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,_curl_tostring))
 	|| (r=curl_easy_setopt(curl,CURLOPT_WRITEDATA,&html))
 	;
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_setopt()",r);
 	r = curl_easy_perform(curl);
 	if(r && r!=CURLE_WRITE_ERROR)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_perform()",r);
 	static const char *re_bre = "<\\s*body\\b", *re_hdre = "<\\s*head[^>]*>",
 		     *re_lre = "<\\s*link\\b([^>]+)>",
 		     *re_rre = "\\brel\\s*=\\s*['\"]([^'\"]+)['\"]",
 		     *re_hre = "\\bhref\\s*=\\s*['\"]\\s*([^'\"\\s]+)\\s*['\"]";
 	pcre_matches_t m1(3), m2(3);
 	pcre_t bre(re_bre,PCRE_CASELESS);
 	if(bre.exec(html,m1)>0)
 	    html.erase(m1.begin(0));
 	pcre_t hdre(re_hdre,PCRE_CASELESS);
 	if(hdre.exec(html,m1)<=0)
 	    throw bad_input(OPKELE_CP_ "failed to find <head>");
 	html.erase(0,m1.end(0)+1);
 	pcre_t lre(re_lre,PCRE_CASELESS), rre(re_rre,PCRE_CASELESS), hre(re_hre,PCRE_CASELESS);
 	bool gotit = false;
 	while( (!gotit) && lre.exec(html,m1)>=2 ) {
 	    static const char *whitespace = " \t";
 	    string attrs(html,m1.begin(1),m1.length(1));
 	    html.erase(0,m1.end(0)+1);
 	    if(!( rre.exec(attrs,m1)>=2 && hre.exec(attrs,m2)>=2 ))
 		continue;
 	    string rels(attrs,m1.begin(1),m1.length(1));
 	    for(string::size_type ns = rels.find_first_not_of(whitespace);
 		    ns!=string::npos;
 		    ns=rels.find_first_not_of(whitespace,ns)) {
 		string::size_type s = rels.find_first_of(whitespace,ns);
 		string rel;
 		if(s==string::npos) {
 		    rel.assign(rels,ns,string::npos);
 		    ns=string::npos;
 		}else{
 		    rel.assign(rels,ns,s-ns);
 		    ns=s;
 		}
 		if(rel=="openid.server") {
 		    server.assign(attrs,m2.begin(1),m2.length(1));
 		    if(!delegate.empty()) {
 			gotit = true;
 			break;
 		    }
 		}else if(rel=="openid.delegate") {
 		    delegate.assign(attrs,m2.begin(1),m2.length(1));
 		    if(!server.empty()) {
 			gotit = true;
 			break;
 		    }
 		}
 		if(ns==string::npos) break;
 	    }
 	}
 	if(server.empty())
 	    throw failed_assertion(OPKELE_CP_ "The location has no openid.server declaration");
     }
 
     assoc_t consumer_t::find_assoc(const string& server) {
 	throw failed_lookup(OPKELE_CP_ "no find_assoc() provided");
     }
 
     string consumer_t::normalize(const string& url) {
 	string rv = url;
 	// strip leading and trailing spaces
 	string::size_type i = rv.find_first_not_of(" \t\r\n");
 	if(i==string::npos)
 	    throw bad_input(OPKELE_CP_ "empty URL");
 	if(i)
 	    rv.erase(0,i);
 	i = rv.find_last_not_of(" \t\r\n");
 	assert(i!=string::npos);
 	if(i<(rv.length()-1))
 	    rv.erase(i+1);
 	// add missing http://
 	i = rv.find("://");
 	if(i==string::npos) { // primitive. but do we need more?
 	    rv.insert(0,"http://");
 	    i = sizeof("http://")-1;
 	}else{
 	    i += sizeof("://")-1;
 	}
 	string::size_type qm = rv.find('?',i);
 	string::size_type sl = rv.find('/',i);
 	if(qm!=string::npos) {
 	    if(sl==string::npos || sl>qm)
 		rv.insert(qm,1,'/');
 	}else{
 	    if(sl==string::npos)
 		rv += '/';
 	}
 	return rv;
     }
 
     string consumer_t::canonicalize(const string& url) {
 	string rv = normalize(url);
 	curl_t curl = curl_easy_init();
 	if(!curl)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_init()");
 	string html;
 	CURLcode r;
 	(r=curl_misc_sets(curl))
 	|| (r=curl_easy_setopt(curl,CURLOPT_URL,rv.c_str()))
 	|| (r=curl_easy_setopt(curl,CURLOPT_NOBODY,1))
 	;
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_setopt()",r);
 	r = curl_easy_perform(curl);
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_perform()",r);
 	const char *eu = 0;
 	r = curl_easy_getinfo(curl,CURLINFO_EFFECTIVE_URL,&eu);
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to curl_easy_getinfo(..CURLINFO_EFFECTIVE_URL..)",r);
 	rv = eu;
 	return normalize(rv);
     }
 
 }