diff --git a/actions/userauthorization.php b/actions/userauthorization.php
index aaa161b68a..6a49af8258 100644
--- a/actions/userauthorization.php
+++ b/actions/userauthorization.php
@@ -20,28 +20,29 @@
 if (!defined('LACONICA')) { exit(1); }
 
 require_once(INSTALLDIR.'/lib/omb.php');
+define('TIMESTAMP_THRESHOLD', 300);
 
 class UserauthorizationAction extends Action {
 	function handle($args) {
 		parent::handle($args);
 		
 		if ($_SERVER['REQUEST_METHOD'] == 'POST') {
+			# We've shown the form, now post user's choice
 			$this->send_authorization();
 		} else {
 			try {
 				common_debug('userauthorization.php - fetching request');
-				$req = $this->get_request();
+				# We get called after login if we have a stored request
+				$req = $this->get_stored_request();
 				if (!$req) {
-					common_server_error(_t('Cannot find request'));
+					# this must be a new request
+					$req = $this->get_new_request();
+					# XXX: only validate new requests, since nonce is one-time use
+					$this->validate_request($req);
+				}
+				if (!$req) {
+					common_server_error(_t('No request found!'));
 				}
-				common_debug('userauthorization.php - $req = "'.print_r($req,TRUE).'"');
-				$server = omb_oauth_server();
-				common_debug('userauthorization.php - getting the consumer');
-				$consumer = $server->get_consumer($req);
-				common_debug('userauthorization.php - $consumer = "'.print_r($consumer,TRUE).'"');
-				$token = $server->get_token($req, $consumer, "request");
-				common_debug('userauthorization.php - $token = "'.print_r($token,TRUE).'"');
-				$server->check_signature($req, $consumer, $token);
 			} catch (OAuthException $e) {
 				$this->clear_request();
 				common_server_error($e->getMessage());
@@ -52,46 +53,426 @@ class UserauthorizationAction extends Action {
 				$this->show_form($req);
 			} else {
 				# Go log in, and then come back
+				$this->store_request($req);
 				common_set_returnto(common_local_url('userauthorization'));
 				common_redirect(common_local_url('login'));
 			}
 		}
 	}
+
+	function show_form($req) {
+
+		$nickname = $req->get_parameter('omb_listenee_nickname');
+		$profile = $req->get_parameter('omb_listenee_profile');
+		$license = $req->get_parameter('omb_listenee_license');
+		$fullname = $req->get_parameter('omb_listenee_fullname');
+		$homepage = $req->get_parameter('omb_listenee_homepage');
+		$bio = $req->get_parameter('omb_listenee_bio');
+		$location = $req->get_parameter('omb_listenee_location');
+		$avatar = $req->get_parameter('omb_listenee_avatar');
+		
+		common_show_header(_t('Authorize subscription'));
+		common_element('p', _t('Please check these details to make sure '.
+							   'that you want to subscribe to this user\'s notices. '.
+							   'If you didn\'t just ask to subscribe to someone\'s notices, '.
+							   'click "Cancel".'));
+		common_element_start('div', 'profile');
+		if ($avatar) {
+			common_element('img', array('src' => $avatar,
+										'class' => 'avatar profile',
+										'width' => AVATAR_PROFILE_SIZE,
+										'height' => AVATAR_PROFILE_SIZE,
+										'alt' => $nickname));
+		}
+		common_element('a', array('href' => $profile,
+								  'class' => 'external profile nickname'),
+					   $nickname);
+		if ($fullname) {
+			common_element_start('div', 'fullname');
+			if ($homepage) {
+				common_element('a', array('href' => $homepage),
+							   $fullname);
+			} else {
+				common_text($fullname);
+			}
+			common_element_end('div');
+		}
+		if ($location) {
+			common_element('div', 'location', $location);
+		}
+		if ($bio) {
+			common_element('div', 'bio', $bio);
+		}
+		common_element_start('div', 'license');
+		common_element('a', array('href' => $license,
+								  'class' => 'license'),
+					   $license);
+		common_element_end('div');
+		common_element_end('div');
+		common_element_start('form', array('method' => 'POST',
+										   'id' => 'userauthorization',
+										   'name' => 'userauthorization',
+										   'action' => common_local_url('userauthorization')));
+		common_submit('accept', _t('Accept'));
+		common_submit('reject', _t('Reject'));		
+		common_element_end('form');
+		common_show_footer();
+	}
+	
+	function send_authorization() {
+		$req = $this->get_stored_request();
+		
+		if (!$req) {
+			common_user_error(_t('No authorization request!'));
+			return;
+		}
+
+		$callback = $req->get_parameter('oauth_callback');
+
+		if ($this->arg('accept')) {
+			$this->authorize_token($req);
+			$this->save_remote_profile($req);
+			if (!$callback) {
+				$this->show_accept_message($req->get_parameter('oauth_token'));
+			} else {
+				$params = array();
+				$params['oauth_token'] = $req->get_parameter('oauth_token');
+				$params['omb_version'] = OMB_VERSION_01;
+				$user = User::staticGet('uri', $req->get_parameter('omb_listener'));
+				$profile = $user->getProfile();
+				$params['omb_listener_nickname'] = $user->nickname;
+				$params['omb_listener_profile'] = common_local_url('showstream',
+																   array('nickname' => $user->nickname));
+				if ($profile->fullname) {
+					$params['omb_listener_fullname'] = $profile->fullname;
+				}
+				if ($profile->homepage) {
+					$params['omb_listener_homepage'] = $profile->homepage;
+				}
+				if ($profile->bio) {
+					$params['omb_listener_bio'] = $profile->bio;
+				}
+				if ($profile->location) {
+					$params['omb_listener_location'] = $profile->location;
+				}
+				$avatar = $profile->getAvatar(AVATAR_PROFILE_SIZE);
+				if ($avatar) {
+					$params['omb_listener_avatar'] = $avatar->url;
+				}
+				$parts = array();
+				foreach ($params as $k => $v) {
+					$parts[] = $k . '=' . OAuthUtil::urlencodeRFC3986($v);
+				}
+				$query_string = implode('&', $parts);
+				$parsed = parse_url($callback);
+				$url = $callback . (($parsed['query']) ? '&' : '?') . $query_string;
+				common_redirect($url, 303);
+			}
+		} else {
+			if (!$callback) {
+				$this->show_reject_message();
+			} else {
+				# XXX: not 100% sure how to signal failure... just redirect without token?
+				common_redirect($callback, 303);
+			}
+		}
+	}
+
+	function authorize_token(&$req) {
+		$consumer_key = @$req->get_parameter('oauth_consumer_key');
+		$token_field = @$req->get_parameter('oauth_token');
+		$rt = new Token();
+		$rt->consumer_key = $consumer_key;
+		$rt->tok = $token_field;
+		if ($rt->find(TRUE)) {
+			$orig_rt = clone($rt);
+			$rt->state = 1; # Authorized but not used
+			if ($rt->update($orig_rt)) {
+				return true;
+			}
+		}
+		return FALSE;
+	}
+
+	# XXX: refactor with similar code in finishremotesubscribe.php
+	
+	function save_remote_profile(&$req) {
+		# FIXME: we should really do this when the consumer comes
+		# back for an access token. If they never do, we've got stuff in a 
+		# weird state.
+		
+		$fullname = $req->get_parameter('omb_listenee_fullname');
+		$profile_url = $req->get_parameter('omb_listenee_profile');		
+		$homepage = $req->get_parameter('omb_listenee_homepage');
+		$bio = $req->get_parameter('omb_listenee_bio');
+		$location = $req->get_parameter('omb_listenee_location');
+		$avatar_url = $req->get_parameter('omb_listenee_avatar');
+		
+		$listenee = $req->get_parameter('omb_listenee');
+		$remote = Remote_profile::staticGet('uri', $listenee);
+		
+		if ($remote) {
+			$exists = true;
+			$profile = Profile::staticGet($remote->id);
+			$orig_remote = clone($remote);
+			$orig_profile = clone($profile);
+		} else {
+			$exists = false;
+			$remote = new Remote_profile();
+			$remote->uri = $omb['listener'];
+			$profile = new Profile();
+		}
+
+		$profile->nickname = $nickname;
+		$profile->profileurl = $profile_url;
+		
+		if ($fullname) {
+			$profile->fullname = $fullname;
+		}
+		if ($homepage) {
+			$profile->homepage = $homepage;
+		}
+		if ($bio) {
+			$profile->bio = $bio;
+		}
+		if ($location) {
+			$profile->location = $location;
+		}
+		
+		if ($exists) {
+			$profile->update($orig_profile);
+		} else {
+			$profile->created = DB_DataObject_Cast::dateTime(); # current time
+			$id = $profile->insert();
+			$remote->id = $id;
+		}
+
+		if ($avatar_url) {
+			$this->add_avatar($avatar_url);
+		}
+
+		if ($exists) {
+			$remote->update($orig_remote);
+		} else {
+			$remote->created = DB_DataObject_Cast::dateTime(); # current time
+			$remote->insert();
+		}
+
+		$user = common_current_user();
+		$datastore = omb_oauth_datastore();
+		$consumer = $this->get_consumer($datastore, $req);
+		$token = $this->get_token($datastore, $req, $consumer);
+
+		$sub = new Subscription();
+		$sub->subscriber = $user->id;
+		$sub->subscribed = $remote->id;
+		$sub->token = $token->key; # NOTE: request token, not valid for use!
+		$sub->created = DB_DataObject_Cast::dateTime(); # current time
+		
+		if (!$sub->insert()) {
+			common_user_error(_t('Couldn\'t insert new subscription.'));
+			return;
+		}
+	}
+	
+	function show_accept_message($tok) {
+		common_show_header(_t('Subscription authorized'));
+		common_element('p', NULL, 
+					   _t('The subscription has been authorized, but no '.
+						  'callback URL was passed. Check with the site\'s instructions for '.
+						  'details on how to authorize the subscription. Your subscription token is:'));
+		common_element('blockquote', 'token', $tok);
+		common_show_footer();
+	}
+
+	function show_reject_message($tok) {
+		common_show_header(_t('Subscription rejected'));
+		common_element('p', NULL, 
+					   _t('The subscription has been rejected, but no '.
+						  'callback URL was passed. Check with the site\'s instructions for '.
+						  'details on how to fully reject the subscription.'));
+		common_show_footer();
+	}
 	
 	function store_request($req) {
 		common_ensure_session();
 		$_SESSION['userauthorizationrequest'] = $req;
 	}
 	
-	function get_request() {
+	function clear_request($req) {
+		common_ensure_session();
+		unset($_SESSION['userauthorizationrequest']);
+	}
+	
+	function get_stored_request() {
 		common_ensure_session();		
 		$req = $_SESSION['userauthorizationrequest'];
-		if (!$req) {
-			# XXX: may have an uncaught exception
-			$req = OAuthRequest::from_request();
-			if ($req) {
-				$this->store_request($req);
-			}
-		}
 		return $req;
 	}
-	
-	function show_form($req) {
-		common_show_header(_t('Authorize subscription'));
 
-		common_show_footer();
+	function get_new_request() {
+		$req = OAuthRequest::from_request();
 	}
 	
-	function send_authorization() {
-		$req = $this->get_request();
-		
-		if (!$req) {
-			common_user_error(_t('No authorization request!'));
-			return;
+	# Throws an OAuthException if anything goes wrong
+	
+	function validate_request($req) {
+		# OAuth stuff -- have to copy from OAuth.php since they're
+		# all private methods, and there's no user-authentication method
+		$this->check_version($req);
+		$datastore = omb_oauth_datastore();
+		$consumer = $this->get_consumer($datastore, $req);
+		$token = $this->get_token($datastore, $req, $consumer);
+		$this->check_timestamp($req);
+		$this->check_nonce($datastore, $req, $consumer, $token);
+		$this->check_signature($req, $consumer, $token);
+		$this->validate_omb($req);
+		return true;
+	}
+
+	function validate_omb(&$req) {
+		foreach (array('omb_version', 'omb_listener', 'omb_listenee',
+					   'omb_listenee_profile', 'omb_listenee_nickname',
+					   'omb_listenee_license') as $param)
+		{
+			if (!$req->get_parameter($param)) {
+				throw new OAuthException("Required parameter '$param' not found");
+			}
+		}
+		# Now, OMB stuff
+		$version = $req->get_parameter('omb_version');
+		if ($version != OMB_VERSION_01) {
+			throw new OAuthException("OpenMicroBlogging version '$version' not supported");
+		}
+		$user = User::staticGet('uri', $req->get_parameter('omb_listener'));
+		if (!$user) {
+			throw new OAuthException("Listener URI '$listener' not found here");
+		}
+		$listenee = $req->get_parameter('omb_listenee');
+		if (!Validate::uri($listenee)) {
+			throw new OAuthException("Listenee URI '$listenee' not a valid URI");
+		} else if (strlen($listenee) > 255) {
+			throw new OAuthException("Listenee URI '$listenee' too long");
+		}
+		$nickname = $req->get_parameter('omb_listenee_nickname');
+		if (!Validate::string($nickname, array('min_length' => 1,
+											   'max_length' => 64,
+											   'format' => VALIDATE_NUM . VALIDATE_ALPHA_LOWER))) {
+			throw new OAuthException('Nickname must have only letters and numbers and no spaces.');
+		}
+		$profile = $req->get_parameter('omb_listenee_profile');
+		if (!common_valid_http_url($profile)) {
+			throw new OAuthException("Invalid profile URL '$profile'.");
+		}
+		$license = $req->get_parameter('omb_listenee_license');
+		if (!common_valid_http_url($license)) {
+			throw new OAuthException("Invalid license URL '$license'.");
+		}
+		# optional stuff
+		$fullname = $req->get_parameter('omb_listenee_fullname');
+		if ($fullname && strlen($fullname) > 255) {
+			throw new OAuthException("Full name '$fullname' too long.");
+		}
+		$homepage = $req->get_parameter('omb_listenee_homepage');
+		if ($homepage && (!common_valid_http_url($homepage) || strlen($homepage) > 255)) {
+			throw new OAuthException("Invalid homepage '$homepage'");
+		}
+		$bio = $req->get_parameter('omb_listenee_bio');
+		if ($bio && strlen($bio) > 140) {
+			throw new OAuthException("Bio too long '$bio'");
+		}
+		$location = $req->get_parameter('omb_listenee_location');
+		if ($location && strlen($location) > 255) {
+			throw new OAuthException("Location too long '$location'");
+		}
+		$avatar = $req->get_parameter('omb_listenee_avatar');
+		if ($avatar && (!common_valid_http_url($avatar) || strlen($avatar) > 255)) {
+			throw new OAuthException("Invalid avatar '$avatar'");
+		}
+		$callback = $req->get_parameter('oauth_callback');
+		if ($avatar && common_valid_http_url($callback)) {
+			throw new OAuthException("Invalid callback URL '$callback'");
+		}
+	}
+	
+	# Snagged from OAuthServer
+	
+	function check_version($req) {
+		$version = $req->get_parameter("oauth_version");
+		if (!$version) {
+			$version = 1.0;
+		}
+		if ($version != 1.0) {
+			throw new OAuthException("OAuth version '$version' not supported");
+		}
+		return $version;
+	}
+
+	# Snagged from OAuthServer
+	
+	function get_consumer($datastore, $req) {
+		$consumer_key = @$req->get_parameter("oauth_consumer_key");
+		if (!$consumer_key) {
+			throw new OAuthException("Invalid consumer key");
 		}
 		
-		if ($this->boolean('authorize')) {
-			
+		$consumer = $datastore->lookup_consumer($consumer_key);
+		if (!$consumer) {
+			throw new OAuthException("Invalid consumer");
 		}
+		return $consumer;
+	}
+
+	# Mostly cadged from OAuthServer
+	
+	function get_token(&$req, $consumer, $datastore) {/*{{{*/
+		$token_field = @$req->get_parameter('oauth_token');
+		$token = $datastore->lookup_token($consumer, 'request', $token_field);
+		if (!$token) {
+			throw new OAuthException("Invalid $token_type token: $token_field");
+		}
+		return $token;
+	}
+	
+	function check_timestamp(&$req) {
+		$timestamp = @$req->get_parameter('oauth_timestamp');
+		$now = time();
+		if ($now - $timestamp > TIMESTAMP_THRESHOLD) {
+			throw new OAuthException("Expired timestamp, yours $timestamp, ours $now");
+		}
+	}
+
+	# NOTE: don't call twice on the same request; will fail!
+	function check_nonce(&$datastore, &$req, $consumer, $token) {
+		$timestamp = @$req->get_parameter('oauth_timestamp');
+		$nonce = @$req->get_parameter('oauth_nonce');
+		$found = $datastore->lookup_nonce($consumer, $token, $nonce, $timestamp);
+		if ($found) {
+			throw new OAuthException("Nonce already used");
+		}
+		return true;
+	}
+	
+	function check_signature(&$req, $consumer, $token) {
+		$signature_method = $this->get_signature_method($req);
+		$signature = $req->get_parameter('oauth_signature');    
+		$valid_sig = $signature_method->check_signature($req, 
+														$consumer, 
+														$token, 
+														$signature);
+		if (!$valid_sig) {
+			throw new OAuthException("Invalid signature");
+		}
+	}
+	
+	function get_signature_method(&$req) {
+		$signature_method = @$req->get_parameter("oauth_signature_method");
+		if (!$signature_method) {
+			$signature_method = "PLAINTEXT";
+		}
+		if ($signature_method != 'HMAC-SHA1') {
+			throw new OAuthException("Signature method '$signature_method' not supported.");
+		}
+		return omb_hmac_sha1();
 	}
 }
diff --git a/lib/oauthstore.php b/lib/oauthstore.php
index 4ad1234551..688c7477a9 100644
--- a/lib/oauthstore.php
+++ b/lib/oauthstore.php
@@ -106,9 +106,21 @@ class LaconicaOAuthDataStore extends OAuthDataStore {
 				$rt->state = 2; # used
 				if (!$rt->update($orig_rt)) {
 					return NULL;
+				} 
+				# Update subscription
+				# XXX: mixing levels here
+				$sub = Subscription::staticGet('token', $rt->tok);
+				if (!$sub) {
+					return NULL;
+				}
+				$orig_sub = clone($sub);
+				$sub->token = $at->tok;
+				$sub->secret = $at->secret;
+				if (!$sub->update($orig_sub)) {
+					return NULL;
 				} else {
 					return new OAuthToken($at->tok, $at->secret);
-				}
+				}					
 			}
 		} else {
 			return NULL;
diff --git a/lib/omb.php b/lib/omb.php
index 19ac66ee28..7c7a21cc8f 100644
--- a/lib/omb.php
+++ b/lib/omb.php
@@ -42,7 +42,7 @@ define('OAUTH_POST_BODY', OAUTH_NAMESPACE.'parameters/post-body');
 define('OAUTH_HMAC_SHA1', OAUTH_NAMESPACE.'signature/HMAC-SHA1');
 	   
 function omb_oauth_consumer() {
-	static $con = null;
+	static $con = NULL;
 	if (!$con) {
 		$con = new OAuthConsumer(common_root_url(), '');
 	}
@@ -52,12 +52,20 @@ function omb_oauth_consumer() {
 function omb_oauth_server() {
 	static $server = null;
 	if (!$server) {
-		$server = new OAuthServer(new LaconicaOAuthDataStore());
+		$server = new OAuthServer(omb_oauth_datastore());
 		$server->add_signature_method(omb_hmac_sha1());
 	}
 	return $server;
 }
 
+function omb_oauth_datastore() {
+	static $store = NULL;
+	if (!$store) {
+		$store = new LaconicaOAuthDataStore();
+	}
+	return $store;
+}
+
 function omb_hmac_sha1() {
 	static $hmac_method = NULL;
 	if (!$hmac_method) {
diff --git a/lib/util.php b/lib/util.php
index de15d13dec..a222f85f65 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -588,4 +588,8 @@ function common_log($priority, $msg) {
 
 function common_debug($msg) {
 	common_log(LOG_DEBUG, $msg);
-}
\ No newline at end of file
+}
+
+function common_valid_http_url($url) {
+	return Validate::uri($url, array('allowed_schemes' => array('http', 'https')));
+}