associations robustness improvements and documentation updates

3 files changed, 24 insertions, 1 deletions

diff --git a/include/opkele/association.h b/include/opkele/association.h
index a8f3915..72eff5b 100644
--- a/include/opkele/association.h
+++ b/include/opkele/association.h
@@ -40,29 +40,31 @@ namespace opkele {
 	     * statelessness of the assoc_handle
 	     */
 	    bool _stateless;
 
 	    /**
 	     * @param __server the server name
 	     * @param __handle association handle
 	     * @param __assoc_type association type
 	     * @param __secret the secret
 	     * @param __expires expiration time
 	     * @param __stateless statelessness of the assoc_handle
 	     */
 	    association(const string& __server, const string& __handle,
 		    const string& __assoc_type, const secret_t& __secret,
 		    time_t __expires, bool __stateless)
 		: _server(__server), _handle(__handle), _assoc_type(__assoc_type),
 		_secret(__secret), _expires(__expires), _stateless(__stateless) { }
 
 	    virtual string server() const { return _server; }
 	    virtual string handle() const { return _handle; }
 	    virtual string assoc_type() const { return _assoc_type; }
 	    virtual secret_t secret() const { return _secret; }
 	    virtual int expires_in() const { return _expires-time(0); }
 	    virtual bool stateless() const { return _stateless; }
+
+	    virtual bool is_expired() const { return _expires<time(0); }
     };
 
 }
 
 #endif /* __OPKELE_ASSOCIATION_H */
diff --git a/include/opkele/consumer.h b/include/opkele/consumer.h
index 042e2d1..b9d1e54 100644
--- a/include/opkele/consumer.h
+++ b/include/opkele/consumer.h
@@ -1,74 +1,91 @@
 #ifndef __OPKELE_CONSUMER_H
 #define __OPKELE_CONSUMER_H
 
 #include <opkele/types.h>
 #include <opkele/extension.h>
 
 /**
  * @file
  * @brief OpenID consumer-side functionality
  */
 
 namespace opkele {
 
     /**
      * implementation of basic consumer functionality
+     *
+     * @note
+     * The consumer uses libcurl internally, which means that if you're using
+     * libopkele in multithreaded environment you should call curl_global_init
+     * yourself before spawning any threads.
      */
     class consumer_t {
 	public:
 
 	    /**
 	     * store association. The function should be overridden in the real
 	     * implementation to provide persistent associations store.
 	     * @param server the OpenID server
 	     * @param handle association handle
 	     * @param secret the secret associated with the server and handle
 	     * @param expires_in the number of seconds until the handle is expired
 	     * @return the auto_ptr<> for the newly allocated association_t object
 	     */
 	    virtual assoc_t store_assoc(const string& server,const string& handle,const secret_t& secret,int expires_in) = 0;
 	    /**
 	     * retrieve stored association. The function should be overridden
 	     * in the real implementation to provide persistent assocations
 	     * store.
+	     *
+	     * @note
+	     * The user is responsible for handling associations expiry and
+	     * this function should never return an expired or invalidated
+	     * association.
+	     *
 	     * @param server the OpenID server
 	     * @param handle association handle
 	     * @return the autho_ptr<> for the newly allocated association_t object
-	     * @throw failed_lookup in case of error
+	     * @throw failed_lookup if no unexpired association found
 	     */
 	    virtual assoc_t retrieve_assoc(const string& server,const string& handle) = 0;
 	    /**
 	     * invalidate stored association. The function should be overridden
 	     * in the real implementation of the consumer.
 	     * @param server the OpenID server
 	     * @param handle association handle
 	     */
 	    virtual void invalidate_assoc(const string& server,const string& handle) = 0;
 	    /**
 	     * retrieve any unexpired association for the server. If the
 	     * function is not overridden in the real implementation, the new
 	     * association will be established for each request.
+	     *
+	     * @note
+	     * The user is responsible for handling associations and this
+	     * function should never return an expired or invalidated
+	     * association.
+	     *
 	     * @param server the OpenID server
 	     * @return the auto_ptr<> for the newly allocated association_t object
 	     * @throw failed_lookup in case of absence of the handle
 	     */
 	    virtual assoc_t find_assoc(const string& server);
 
 	    /**
 	     * retrieve the metainformation contained in link tags from the
 	     * page pointed by url. the function may implement caching of the
 	     * information.
 	     * @param url url to harvest for link tags
 	     * @param server reference to the string object where to put
 	     * openid.server value
 	     * @param delegate reference to the string object where to put the
 	     * openid.delegate value (if any)
 	     */
 	    virtual void retrieve_links(const string& url,string& server,string& delegate);
 
 	    /**
 	     * perform the associate request to OpenID server.
 	     * @param server the OpenID server
 	     * @return the auto_ptr<> for the newly allocated association_t
 	     * object, representing established association
 	     * @throw exception in case of error
diff --git a/lib/consumer.cc b/lib/consumer.cc
index dd8e150..af309c1 100644
--- a/lib/consumer.cc
+++ b/lib/consumer.cc
@@ -123,65 +123,69 @@ namespace opkele {
 
     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();
+	    if(ah->is_expired()) /* TODO: or should I throw some other exception to force programmer fix his implementation? */
+		throw failed_lookup(OPKELE_CP_ "find_assoc() has returned expired 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(),