Log in, log outHEADmaster

11 files changed, 381 insertions, 166 deletions

diff --git a/Makefile b/Makefile
index f6f78ac..ae09e1c 100644
--- a/Makefile
+++ b/Makefile
@@ -37,4 +37,5 @@ db:
 	sqlite3 db "INSERT INTO posts values(NULL, 1, 1462137896, NULL, 'Hello World!', 'This is the first post.');"
 	sqlite3 db "INSERT INTO posts values(1, 1, 1462138896, NULL, 'Re: Hello World!', 'This is the second post!');"
 	sqlite3 db "CREATE TABLE atts(post INT NOT NULL, name NOT NULL, desc, mime NOT NULL, data BLOB, FOREIGN KEY (post) REFERENCES posts(oid));"
-	sqlite3 db "$$(printf "INSERT INTO atts values(1, 'example', 'Some example shell code.', 'text/plain', '#!/bin/sh\necho Hello World!');")"
\ No newline at end of file
+	sqlite3 db "$$(printf "INSERT INTO atts values(1, 'example', 'Some example shell code.', 'text/plain', '#!/bin/sh\necho Hello World!');")"
+	sqlite3 db "CREATE TABLE sessions(user INT NOT NULL, string NOT NULL, created INT NOT NULL, FOREIGN KEY (user) REFERENCES users(oid));"
diff --git a/README b/README
index e84f8a4..93d8782 100644
--- a/README
+++ b/README
@@ -8,12 +8,12 @@ C89, it can be run on practically any UNIX system.
 It is also rather small:
 
 	wc -l *.c *.h crypt/*.c crypt/*.h */*.t */*.lex
-	      97 cforum.c
-	     381 ctl.c
-	     306 db.c
+	     138 cforum.c
+	     404 ctl.c
+	     403 db.c
 	      11 err.c
-	     144 query.c
-	     101 cforum.h
+	     171 query.c
+	     120 cforum.h
 	     907 crypt/crypt_blowfish.c
 	     124 crypt/crypt_gensalt.c
 	     551 crypt/wrapper.c
@@ -23,11 +23,11 @@ It is also rather small:
 	      43 crypt/ow-crypt.h
 	       3 t/err.t
 	       1 t/foot.t
-	      30 t/front.t
+	      37 t/front.t
 	      15 t/head.t
 	      18 t/login.t
 	      38 t/newuser.t
 	      28 t/post.t
 	      12 t/user.t
 	      95 mktpl/mktpl.lex
-	    2986 total
+	    3200 total
diff --git a/cforum.c b/cforum.c
index b536827..fbd5d85 100644
--- a/cforum.c
+++ b/cforum.c
@@ -10,10 +10,11 @@
 int
 main(int argc, char *argv[])
 {
-	char msg[MAXMSG], *new, *p, *v;
-	int attid, postid, userid;
+	char *delete, *home, *k, msg[MAXMSG], *new, *ssecret, *v;
+	int attid, postid, suser, userid;
+	struct session *session;
 	sqlite3_stmt *stmt;
-	
+
 	/*
 	 * The database is opened or a server error is generated.
 	 * In the rest of the program, the database is always
@@ -27,7 +28,7 @@ main(int argc, char *argv[])
 		sqlite3_close(db);
 		return 1;
 	}
-	
+
 	/*
 	 * The site name is retrieved from the database. This early on,
 	 * it is appropriate to die with a server error on failure.
@@ -52,30 +53,60 @@ main(int argc, char *argv[])
 		return 1;
 	}
 	sqlite3_finalize(stmt);
-	
+
 	/*
 	 * The global struct query is set, or the program dies.
 	 * From now on, query is assumed to be set.
 	 */
 	setquery();
-	
+
+	/* Check session. */
+	curuser = NULL;
+	ssecret = NULL;
+	suser = -1;
+	while(k = nextcookie(MAXCOOKIE+20)){
+		v = split(k);
+		if(!ssecret && strcmp(k, "session") == 0) ssecret = strdup(v);
+		else if(suser == -1 && strcmp(k, "user") == 0) suser = atoi(v);
+	}
+
+	if(sqlite3_prepare(db,
+	    "SELECT oid, * FROM sessions WHERE user = ? AND string = ?",
+	    -1, &stmt, 0) != SQLITE_OK)
+		goto skip;
+
+	if(sqlite3_bind_int(stmt, 1, suser) != SQLITE_OK)
+		goto skip;
+
+	if(sqlite3_bind_text(stmt, 2, ssecret, -1, SQLITE_STATIC) != SQLITE_OK)
+		goto skip;
+
+	if(!(session = getsession(stmt)))
+		goto skip;
+
+	/* Session is valid. */
+	cursession = session;
+	curuser = getuser(selectbyint("users", "oid", suser));
+
+skip:
 	/* Handle empty request. */
 	if(!*query.string){
 		showfront();
 		goto end;
 	}
-	
+
 	/* Parse query string. */
-	new = NULL;
+	new = delete = NULL;
 	attid = postid = userid = 0;
-	while(p = nextparam(GET, NULL, 128)){
-		v = split(p);
-		if(!attid && strcmp(p, "att") == 0) attid = atoi(v);
-		else if(!postid && strcmp(p, "post") == 0) postid = atoi(v);
-		else if(!userid && strcmp(p, "user") == 0) userid = atoi(v);
-		else if(!new && strcmp(p, "new") == 0) new = strdup(v);
+	while(k = nextparam(GET, NULL, 128)){
+		v = split(k);
+		if(!attid && strcmp(k, "att") == 0) attid = atoi(v);
+		else if(!postid && strcmp(k, "post") == 0) postid = atoi(v);
+		else if(!userid && strcmp(k, "user") == 0) userid = atoi(v);
+		else if(!new && strcmp(k, "new") == 0) new = strdup(v);
+		else if(!delete && strcmp(k,"delete") == 0) delete = strdup(v);
 	}
-	
+
 	/* Handle request. */
 	if(attid)
 		showatt(attid);
@@ -89,9 +120,19 @@ main(int argc, char *argv[])
 		else if(strcmp(v, "user") == 0) newuser();
 		else if(strcmp(v, "session") == 0) newsession();
 		else showfront(); /* TODO */
+	}
+	else if(delete){
+		if(strcmp(v, "session") == 0){
+			if(cursession)
+				deletesession(cursession);
+			home = getenv("REQUEST_URI");
+			home[strcspn(home, "?")] = 0;
+			printf("Status: 303 See Other\n");
+			printf("Location: %s\n\n", home);
+		}
 	}else
 		showfront();
-	
+
 end:
 	sqlite3_close(db);
 	return 0;
diff --git a/cforum.h b/cforum.h
index 7d7dc60..7285e76 100644
--- a/cforum.h
+++ b/cforum.h
@@ -27,6 +27,13 @@ struct post{
 	char *text;
 };
 
+struct session{
+	int id;
+	int user;
+	int created;
+	char *string;
+};
+
 struct user{
 	int id;
 	int created;
@@ -60,14 +67,20 @@ void showuser(int);
 
 /* db.c */
 int addatt(struct att *);
+int addpost(struct post *);
+int addsession(struct session *);
 int adduser(struct user *);
+int deletesession(struct session *);
 int haspass(struct user *, char *);
+void makerandom(char *, int);
 void makehash(char *, char **, char **);
 struct att *getatt(sqlite3_stmt *);
 struct post *getpost(sqlite3_stmt *);
+struct session *getsession(sqlite3_stmt *);
 struct user *getuser(sqlite3_stmt *);
 struct att *nextatt(sqlite3_stmt *);
 struct post *nextpost(sqlite3_stmt *);
+struct session *nextsession(sqlite3_stmt *);
 struct user *nextuser(sqlite3_stmt *);
 sqlite3_stmt *selectbyint(char *, char *, int);
 
@@ -75,6 +88,7 @@ sqlite3_stmt *selectbyint(char *, char *, int);
 void srverr(char *);
 
 /* query.c */
+char *nextcookie(int);
 char *nextparam(enum method, int *, int);
 void setquery(void);
 char *split(char *);
@@ -95,8 +109,13 @@ int urldecode(char *, int);
 #define MAXUSERFULL 128
 #define MAXUSERPASS 72
 
+/* Maximum size of cookie values. */
+#define MAXCOOKIE 40
+
 /***** Variables *****/
 
 sqlite3 *db;
 struct query query;
-struct site site;
\ No newline at end of file
+struct site site;
+struct user *curuser;
+struct session *cursession;
\ No newline at end of file
diff --git a/ctl.c b/ctl.c
index 9583c44..39581c2 100644
--- a/ctl.c
+++ b/ctl.c
@@ -1,41 +1,16 @@
 #include <err.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#include <unistd.h>
 #include "cforum.h"
 
 #define MAXMSG 256
 
-/* Print UNIX timestamp as written date. */
-void
-printdate(int timestamp)
-{
-	char buf[20];
-	struct tm *t;
-	
-	t = localtime((time_t *)&timestamp);
-	strftime(buf, 20, "%Y-%m-%d %H:%M", t);
-	
-	printf(buf);
-}
-
-/* Print HTML-escaped string. */
-void
-printhtml(char *s)
-{
-	char *t;
-	
-	for(t = s; *t; t++)
-		switch(*t){
-		case '&': printf("&amp;"); break;
-		case '\"': printf("&quot;"); break;
-		case '\'': printf("&apos;"); break;
-		case '<': printf("&lt;"); break;
-		case '>': printf("&gt;"); break;
-		default: printf("%c", *t);
-		}
-}
+static void printdate(int);
+static void printhtml(char *);
 
 /*
  * The `new' functions provide a way to add a new attachment/post/user.
@@ -53,21 +28,26 @@ newpost()
 void
 newsession()
 {
-	char *hlite, msg[MAXMSG], *p, *v;
+	char *hlite, *home, msg[MAXMSG], *p, rnd[MAXCOOKIE], *v;
 	char *name, *pass, *remember;
-	char title[] = "Log In";
 	struct user *user;
+	struct session session;
 	sqlite3_stmt *stmt;
-	
+
+	char title[] = "Log In";
+
 	*msg = 0;
 	hlite = name = pass = remember = NULL;
-	
+
+	home = getenv("REQUEST_URI");
+	home[strcspn(home, "?")] = 0;
+
 	if(query.method == GET){
 		printf("Content-Type: text/html\n\n");
 		#include "t/login.tc"
 		return;
 	}
-	
+
 	if(query.length > MAXSESSIONDATA){
 		snprintf(msg, MAXMSG, "Input exceeded server limitations");
 		printf("Status: 431 Request Header Fields Too Large\n");
@@ -75,10 +55,10 @@ newsession()
 		#include "t/login.tc"
 		return;
 	}
-	
+
 	while(p = nextparam(POST, NULL, MAXSESSIONDATA)){
 		if(!(v = split(p))) continue;
-		
+
 		if(!name && strcmp(p, "name") == 0)
 			name = strdup(v);
 		else if(!pass && strcmp(p, "pass") == 0)
@@ -88,7 +68,7 @@ newsession()
 		else
 			continue;
 	}
-	
+
 	if(!name || !*name){
 		snprintf(msg, MAXMSG, "Username may not be empty");
 		printf("Status: 400 Bad Request\n");
@@ -96,28 +76,42 @@ newsession()
 		#include "t/login.tc"
 		return;
 	}
-	
-	if(sqlite3_prepare(db, "SELECT oid, * from users WHERE name = ?",
+
+	if(sqlite3_prepare(db, "SELECT oid, * FROM users WHERE name = ?",
 	    -1, &stmt, 0) != SQLITE_OK)
 		goto fail;
-	
+
 	if(sqlite3_bind_text(stmt, 1, name, -1, SQLITE_STATIC) != SQLITE_OK)
 		goto dberr;
-	
+
 	if(!(user = getuser(stmt)))
 		goto fail;
-	
+
 	if(!haspass(user, pass))
 		goto fail;
+
+	/* Create session cookie. */
+	makerandom(rnd, sizeof(rnd));
+	session.user = user->id;
+	session.string = rnd;
+	if(!addsession(&session)){
+		snprintf(msg, MAXMSG, "Could not create session for user");
+		printf("Status: 500 Internal Server Error");
+		printf("Content-Type: text/html\n\n");
+		#include "t/login.tc"
+		return;
+	}
 	
-	printf("Content-Type: text/plain\n\n");
-	printf("Success!\n");
+	printf("Status: 303 See Other\n");
+	printf("Set-Cookie: user=%d\n", user->id);
+	printf("Set-Cookie: session=%s\n", rnd);
+	printf("Location: %s\n\n", home);
 	return;
 
 dberr:
 	snprintf(msg, MAXMSG, "Could not retrieve user: %s",
 	    sqlite3_errmsg(db));
-	printf("Status: 500 Internal Server Errror\n");
+	printf("Status: 500 Internal Server Error\n");
 	printf("Content-Type: text/html\n\n");
 	#include "t/login.tc"
 	return;
@@ -136,16 +130,16 @@ newuser()
 	char title[] = "New User";
 	int i;
 	struct user *user;
-	
+
 	*msg = 0;
 	captcha = confirm = hlite = name = full = pass = NULL;
-	
+
 	if(query.method == GET){
 		printf("Content-Type: text/html\n\n");
 		#include "t/newuser.tc"
 		return;
 	}
-	
+
 	if(query.length > MAXUSERDATA){
 		snprintf(msg, MAXMSG, "Input exceeded server limitations");
 		printf("Status: 431 Request Header Fields Too Large\n");
@@ -153,10 +147,10 @@ newuser()
 		#include "t/newuser.tc"
 		return;
 	}
-	
+
 	while(p = nextparam(POST, NULL, MAXUSERDATA)){
 		if(!(v = split(p))) continue;
-		
+
 		if(!captcha && strcmp(p, "captcha") == 0)
 			captcha = strdup(v);
 		if(!confirm && strcmp(p, "confirm") == 0)
@@ -170,7 +164,7 @@ newuser()
 		else
 			continue;
 	}
-	
+
 	/* Decode URL-encoded fields. */
 	if(captcha && *captcha)
 		captcha[urldecode(captcha, -1)] = 0;
@@ -182,7 +176,7 @@ newuser()
 		full[urldecode(full, -1)] = 0;
 	if(pass && *pass)
 		pass[urldecode(pass, -1)] = 0;
-	
+
 	/* Constrain lengths of decoded fields. */
 	if(name && *name && strlen(name)-1 > MAXUSERNAME){
 		hlite = strdup("name");
@@ -202,10 +196,10 @@ newuser()
 		    MAXUSERPASS-1);
 		goto err;
 	}
-	
+
 #define ISVIS(c) ((unsigned char)c >= 32)
 #define ISALNUM(c) (c>='A' && c<='Z' || c>='a' && c<='z' || c>='0' && c<='9')
-	
+
 	/* Constrain character sets. */
 	for(i = 0; name[i]; i++)
 		if(!name[i] == '_' && !ISALNUM(name[i])){
@@ -217,13 +211,12 @@ newuser()
 		}
 	for(i = 0; full[i]; i++)
 		if(!ISVIS(full[i])){
-			fprintf(stderr, "%d\n", full[i]);
 			hlite = strdup("full");
 			snprintf(msg, MAXMSG,
 			    "Full name may only contain visible characters");
 			goto err;
 		}
-	
+
 	/* Validate captcha. */
 	if(captcha && strcmp(captcha, "9") != 0){
 		hlite = strdup("captcha");
@@ -247,14 +240,14 @@ newuser()
 		snprintf(msg, MAXMSG, "Passwords do not match");
 		goto err;
 	}
-	
+
 	if(!(user = malloc(sizeof(struct user))))
 		err(1, "malloc");
-	
+
 	user->name = name;
 	user->full = *full? full: NULL;
 	makehash(pass, &user->hash, &user->salt);
-	
+
 	if(!adduser(user)){
 		if(strcmp(sqlite3_errmsg(db), "column name is not unique")==0)
 			snprintf(msg, MAXMSG, "Username already exists.");
@@ -263,7 +256,7 @@ newuser()
 			    sqlite3_errmsg(db));
 		goto err;
 	}
-	
+
 	printf("Content-Type: text/html\n\n");
 	snprintf(msg, MAXMSG, "SUCCESS: User was added to database");
 	#include "t/newuser.tc"
@@ -275,6 +268,36 @@ err:
 	return;
 }
 
+/* Print UNIX timestamp as written date. */
+void
+printdate(int timestamp)
+{
+	char buf[20];
+	struct tm *t;
+
+	t = localtime((time_t *)&timestamp);
+	strftime(buf, 20, "%Y-%m-%d %H:%M", t);
+
+	printf(buf);
+}
+
+/* Print HTML-escaped string. */
+void
+printhtml(char *s)
+{
+	char *t;
+
+	for(t = s; *t; t++)
+		switch(*t){
+		case '&': printf("&amp;"); break;
+		case '\"': printf("&quot;"); break;
+		case '\'': printf("&apos;"); break;
+		case '<': printf("&lt;"); break;
+		case '>': printf("&gt;"); break;
+		default: printf("%c", *t);
+		}
+}
+
 /*
  * The `show' functions show an existing attachment/post/user
  * or some other type of page.
@@ -283,12 +306,12 @@ void
 showatt(id)
 {
 	struct att *att;
-	
+
 	if(!(att = getatt(selectbyint("atts", "oid", id)))){
 		srverr("Could not retrieve attachment");
 		return;
 	}
-	
+
 	printf("Content-Type: %s\n\n", att->mime);
 	printf("%.*s", att->bytes, att->data);
 	free(att);
@@ -301,21 +324,21 @@ showfront()
 	struct post *post;
 	struct user *user;
 	sqlite3_stmt *pstmt, *ustmt;
-	
+
 	if(sqlite3_prepare(db,
 	    "SELECT oid, * from posts ORDER BY created DESC",
 	    -1, &pstmt, 0) != SQLITE_OK){
 		srverr("Could not retrieve posts");
 		return;
 	}
-	
+
 	if(sqlite3_prepare(db,
 	    "SELECT oid, * from users ORDER BY created DESC",
 	    -1, &ustmt, 0) != SQLITE_OK){
 		srverr("Could not retrieve users");
 		return;
 	}
-	
+
 	title = site.name;
 	printf("Content-Type: text/html\n\n");
 	#include "t/front.tc"
@@ -329,19 +352,19 @@ showpost(int id)
 	struct post *post;
 	struct user *user;
 	sqlite3_stmt *stmt;
-	
+
 	if(!(post = getpost(selectbyint("posts", "oid", id)))){
 		srverr("Could not retrieve post");
 		return;
 	}
-	
+
 	if(!(user = getuser(selectbyint("users", "oid", post->user)))){
 		srverr("Could not retrieve post author");
 		return;
 	}
-	
+
 	stmt = selectbyint("atts", "post", id);
-	
+
 	title = post->subject;
 	printf("Content-Type: text/html\n\n");
 	#include "t/post.tc"
@@ -356,26 +379,26 @@ showuser(int id)
 	sqlite3_stmt *stmt;
 	struct post *post;
 	struct user *user;
-	
+
 	if(!(user = getuser(selectbyint("users", "oid", id)))){
 		srverr("Could not retrieve user");
 		return;
 	}
-	
+
 	if(sqlite3_prepare(db,
 	    "SELECT oid, * from posts WHERE user = ? ORDER BY created DESC",
 	    -1, &stmt, 0) != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_int(stmt, 1, id) != SQLITE_OK)
 		goto err;
-	
+
 	snprintf(title, 120, "User: %s", user->full? user->full: user->name);
 	printf("Content-Type: text/html\n\n");
 	#include "t/user.tc"
 	free(user);
 	return;
-	
+
 err:
 	srverr("Could not retrieve posts");
 	return;
diff --git a/db.c b/db.c
index 4b1b234..29797d3 100644
--- a/db.c
+++ b/db.c
@@ -9,7 +9,7 @@
 #include "cforum.h"
 #include "crypt/ow-crypt.h"
 
-static char * strdupn(const unsigned char *);
+static char *strdupn(const unsigned char *);
 
 /*
  * The `add' functions insert an att/post/user struct into the database.
@@ -24,30 +24,30 @@ addatt(struct att *att)
 	    " VALUES (?, ?, ?, ?, ?)",
 	    -1, &stmt, 0) != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_int(stmt, 1, att->post)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_text(stmt, 2, att->name, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_text(stmt, 3, att->desc, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_text(stmt, 4, att->mime, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_blob(stmt, 5, att->data, att->bytes, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_step(stmt) != SQLITE_DONE)
 		goto err;
-	
+
 	sqlite3_finalize(stmt);
 	return 1;
 err:
@@ -65,27 +65,58 @@ addpost(struct post *post)
 	    " VALUES (?, ?, ?, ?, ?)",
 	    -1, &stmt, 0) != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_int(stmt, 1, post->parent) != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_int(stmt, 2, post->user) != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_int(stmt, 3, post->created) != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_text(stmt, 4, post->subject, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_text(stmt, 5, post->text, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_step(stmt) != SQLITE_DONE)
 		goto err;
-	
+
+	sqlite3_finalize(stmt);
+	return 1;
+err:
+	sqlite3_finalize(stmt);
+	return 0;
+}
+
+int
+addsession(struct session *session)
+{
+	sqlite3_stmt *stmt;
+
+	if(sqlite3_prepare(db, "INSERT INTO sessions"
+	    " (user, string, created)"
+	    " VALUES (?, ?, ?)",
+	    -1, &stmt, 0) != SQLITE_OK)
+		goto err;
+
+	if(sqlite3_bind_int(stmt, 1, session->user) != SQLITE_OK)
+		goto err;
+
+	if(sqlite3_bind_text(stmt, 2, session->string, -1, SQLITE_STATIC)
+	    != SQLITE_OK)
+		goto err;
+
+	if(sqlite3_bind_int(stmt, 3, time(NULL)) != SQLITE_OK)
+		goto err;
+
+	if(sqlite3_step(stmt) != SQLITE_DONE)
+		goto err;
+
 	sqlite3_finalize(stmt);
 	return 1;
 err:
@@ -103,15 +134,15 @@ adduser(struct user *user)
 	    " VALUES (?, ?, ?, ?, ?)",
 	    -1, &stmt, 0) != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_text(stmt, 1, user->name, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_text(stmt, 2, user->full, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_text(stmt, 3, user->hash, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
@@ -119,13 +150,13 @@ adduser(struct user *user)
 	if(sqlite3_bind_text(stmt, 4, user->salt, -1, SQLITE_STATIC)
 	    != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_bind_int(stmt, 5, time(NULL)) != SQLITE_OK)
 		goto err;
-	
+
 	if(sqlite3_step(stmt) != SQLITE_DONE)
 		goto err;
-	
+
 	sqlite3_finalize(stmt);
 	return 1;
 err:
@@ -133,6 +164,21 @@ err:
 	return 0;
 }
 
+int
+deletesession(struct session *session)
+{
+	sqlite3_stmt *stmt;
+
+	if(sqlite3_prepare(db, "DELETE FROM sessions WHERE oid = ?",
+	    -1, &stmt, 0) != SQLITE_OK)
+		return 0;
+
+	if(sqlite3_bind_int(stmt, 1, session->id) != SQLITE_OK)
+		return 0;
+
+	return sqlite3_step(stmt) != SQLITE_ROW;
+}
+
 /*
  * The `get' functions retrieve an att/post/user struct once,
  * after which the statement is automatically finalized.
@@ -155,6 +201,15 @@ getpost(sqlite3_stmt *stmt)
 	return post;
 }
 
+struct session *
+getsession(sqlite3_stmt *stmt)
+{
+	struct session *session;
+	session = nextsession(stmt);
+	sqlite3_finalize(stmt);
+	return session;
+}
+
 struct user *
 getuser(sqlite3_stmt *stmt)
 {
@@ -169,27 +224,47 @@ int
 haspass(struct user *user, char *pass)
 {
 	char *newhash;
-	
+
 	newhash = crypt(pass, user->salt);
 	return strcmp(user->hash, newhash) == 0;
 }
 
+/* Generate string of size-1 random lowercase letters. */
+void
+makerandom(char *buf, int size)
+{
+	int fd, i;
+	
+	if((fd = open("/dev/urandom", O_RDONLY)) == -1)
+		err(1, "open");
+
+	if(read(fd, buf, size-1) == -1)
+		err(1, "read");
+
+	close(fd);
+
+	/* Convert to lowercase letters. */
+	for(i = 0; i < size; i++)
+		buf[i] = (buf[i]+128)%25+97;
+	buf[size] = 0;
+}
+
 /* Generate new salt and hash for password. */
 void
 makehash(char *pass, char **hash, char **salt)
 {
 	char data[50];
-	int fd;
-	
-	if(fd = open("/dev/urandom", O_RDONLY) == -1)
+	int fd, n;
+
+	if((fd = open("/dev/urandom", O_RDONLY)) == -1)
 		err(1, "open");
 
-	if(read(fd, data, sizeof(data)) == -1)
+	if((n = read(fd, data, sizeof(data))) == -1)
 		err(1, "read");
-	
+
 	if(!(*salt = crypt_gensalt("$2b$", 10, data, sizeof(data))))
 		err(1, "crypt_gensalt");
-	
+
 	*hash = crypt(pass, *salt);
 	close(fd);
 }
@@ -203,28 +278,28 @@ struct att *
 nextatt(sqlite3_stmt *stmt)
 {
 	struct att *att;
-	
+
 	if(!stmt)
 		return NULL;
-	
+
 	if(sqlite3_step(stmt) != SQLITE_ROW)
 		return NULL;
-	
+
 	if(!(att = malloc(sizeof(struct att))))
 		err(1, "malloc");
-	
+
 	att->id = sqlite3_column_int(stmt, 0);
 	att->post = sqlite3_column_int(stmt, 1);
 	att->name = strdupn(sqlite3_column_text(stmt, 2));
 	att->desc = strdupn(sqlite3_column_text(stmt, 3));
 	att->mime = strdupn(sqlite3_column_text(stmt, 4));
-	
+
 	att->bytes = sqlite3_column_bytes(stmt, 5);
 	if(!(att->data = malloc(att->bytes)))
 		err(1, "malloc");
 	memcpy(att->data, sqlite3_column_blob(stmt, 5),
 	    att->bytes);
-	
+
 	return att;
 }
 
@@ -232,16 +307,16 @@ struct post *
 nextpost(sqlite3_stmt *stmt)
 {
 	struct post *post;
-	
+
 	if(!stmt)
 		return NULL;
-	
+
 	if(sqlite3_step(stmt) != SQLITE_ROW)
 		return NULL;
-	
+
 	if(!(post = malloc(sizeof(struct post))))
 		err(1, "malloc");
-	
+
 	post->id = sqlite3_column_int(stmt, 0);
 	post->parent = sqlite3_column_int(stmt, 1);
 	post->user = sqlite3_column_int(stmt, 2);
@@ -249,31 +324,53 @@ nextpost(sqlite3_stmt *stmt)
 	post->edited = sqlite3_column_int(stmt, 4);
 	post->subject = strdupn(sqlite3_column_text(stmt, 5));
 	post->text = strdupn(sqlite3_column_text(stmt, 6));
-	
+
 	return post;
 }
 
+struct session *
+nextsession(sqlite3_stmt *stmt)
+{
+	struct session *session;
+
+	if(!stmt)
+		return NULL;
+
+	if(sqlite3_step(stmt) != SQLITE_ROW)
+		return NULL;
+
+	if(!(session = malloc(sizeof(struct session))))
+		err(1, "malloc");
+
+	session->id = sqlite3_column_int(stmt, 0);
+	session->user = sqlite3_column_int(stmt, 1);
+	session->string = strdupn(sqlite3_column_text(stmt, 2));
+	session->created = sqlite3_column_int(stmt, 3);
+
+	return session;
+}
+
 struct user *
 nextuser(sqlite3_stmt *stmt)
 {
 	struct user *user;
-	
+
 	if(!stmt)
 		return NULL;
-	
+
 	if(sqlite3_step(stmt) != SQLITE_ROW)
 		return NULL;
-	
+
 	if(!(user = malloc(sizeof(struct user))))
 		err(1, "malloc");
-	
+
 	user->id = sqlite3_column_int(stmt, 0);
 	user->name = strdupn(sqlite3_column_text(stmt, 1));
 	user->full = strdupn(sqlite3_column_text(stmt, 2));
 	user->hash = strdupn(sqlite3_column_text(stmt, 3));
 	user->salt = strdupn(sqlite3_column_text(stmt, 4));
 	user->created = sqlite3_column_int(stmt, 5);
-	
+
 	return user;
 }
 
@@ -287,15 +384,15 @@ selectbyint(char *table, char *field, int i)
 {
 	char sql[100];
 	sqlite3_stmt *stmt;
-	
+
 	snprintf(sql, 100, "SELECT oid, * FROM %s WHERE %s = ?", table, field);
-	
+
 	if(sqlite3_prepare(db, sql, -1, &stmt, 0) != SQLITE_OK)
 		return NULL;
-		
+
 	if(sqlite3_bind_int(stmt, 1, i) != SQLITE_OK)
 		return NULL;
-	
+
 	return stmt;
 }
 
diff --git a/err.c b/err.c
index 07a50a2..35a5666 100644
--- a/err.c
+++ b/err.c
@@ -5,7 +5,7 @@ void
 srverr(char *err)
 {
 	char title[] = "500 Internal Server Error";
-	
+
 	printf("Status: %s\n", title);
 	printf("Content-Type: text/html\n\n");
 	#include "t/err.tc"
diff --git a/mktpl/README b/mktpl/README
index 85a2fe3..cb50a6e 100644
--- a/mktpl/README
+++ b/mktpl/README
@@ -20,7 +20,7 @@ is compiled to the following C code:
 	/* This C code will be executed. */
 	for(i = 0; i<10; i++) printf("Hello World!\n");
 	strcpy(s, "This");
-	
+
 	printf("\n");
 	printf("%s",  s );
 	printf(" will be evaluated and printed as a string.");
diff --git a/mktpl/mktpl.lex b/mktpl/mktpl.lex
index e184c0e..296cc0b 100644
--- a/mktpl/mktpl.lex
+++ b/mktpl/mktpl.lex
@@ -5,12 +5,12 @@
 	#include <stdio.h>
 	#include <stdlib.h>
 	#include <string.h>
-	
+
 	void apnd();
 	void eval();
 	void text();
 	void prnt();
-	
+
 	char *buf;
 	int len;
 	int sz;
@@ -38,7 +38,7 @@ main(int argc, char *argv[])
 	sz = 512;
 	if(!(buf = malloc(sz)))
 		err(1, "malloc");
-	
+
 	yylex();
 	return 0;
 }
@@ -51,7 +51,7 @@ apnd()
 		if(!(buf = realloc(buf, sz)))
 			err(1, "realloc");
 	}
-	
+
 	buf[len++] = *yytext;
 }
 
@@ -66,9 +66,9 @@ void
 text()
 {
 	int i, ofs;
-	
+
 	if(!len) return;
-	
+
 	printf("printf(\"");
 	for(i = ofs = 0; i < len; i++){
 		/*
diff --git a/query.c b/query.c
index 8f54ead..1f3fe88 100644
--- a/query.c
+++ b/query.c
@@ -4,6 +4,33 @@
 #include <string.h>
 #include "cforum.h"
 
+/* Return an allocated string containing the next cookie ("name=value"). */
+char *
+nextcookie(int max)
+{
+	char *buf;
+	int n;
+	static char *cs = NULL;
+
+	if(!(buf = malloc(max)))
+		err(1, "malloc");
+
+	if(!cs)
+		cs = getenv("HTTP_COOKIE");
+
+	if(!cs || !*cs)
+		return NULL;
+
+	if(*cs == ' ')
+		cs++;
+
+	n = strcspn(cs, ";");
+	snprintf(buf, max, "%.*s", n, cs);
+	cs += n + (n != strlen(cs));
+
+	return buf;
+}
+
 /*
  * Return an allocated string containing the next parameter ("key=value").
  * The method argument decides which data (GET or POST) to read from.
@@ -21,17 +48,17 @@ nextparam(enum method method, int *len, int max)
 	char *buf;
 	int i, sz;
 	static int j = 0;
-	
+
 	/* Return NULL if at end of parameter string. */
 	if(method == GET && !query.string[j-1])
 		return NULL;
-	
+
 #define STEP 256
-	
+
 	sz = STEP;
 	if(!(buf = malloc(1+sz))) /* Leave space for -1th character. */
 		err(1, "malloc");
-	
+
 	/*
 	 * buf's -1th character is set to 1 if the string
 	 * has been truncated (i.e. if input exceeded max).
@@ -51,14 +78,14 @@ first:
 	/* Return NULL if at end of parameter string. */
 	if(!READ(buf))
 		return NULL;
-	
+
 	/* Skip empty parameters. */
 	if(*buf == '&')
 		goto first;
-	
+
 	i = 0;
 	goto rest;
-	
+
 	for(; READ(buf+i); i++){
 rest:
 		if(buf[i] == '&'){
@@ -80,7 +107,7 @@ rest:
 	}
 	if(len) *len = i;
 	else buf[i] = 0;
-	
+
 	return buf;
 }
 
@@ -125,10 +152,10 @@ int
 urldecode(char *s, int len)
 {
 	unsigned int code, i, j;
-	
+
 	if(len < 0)
 		len = strlen(s);
-	
+
 	for(i = j = 0; i < len; i++, j++){
 		if(s[i] == '+')
 			s[j] = ' ';
@@ -140,6 +167,6 @@ urldecode(char *s, int len)
 		}else
 			s[j] = s[i];
 	}
-	
+
 	return j;
 }
\ No newline at end of file
diff --git a/t/front.t b/t/front.t
index 4f94a9b..f8dc9e3 100644
--- a/t/front.t
+++ b/t/front.t
@@ -1,8 +1,15 @@
 <% #include "head.tc" %>
 <h1><%= site.name %></h1>
+<% if(curuser) { %>
+Logged in as <%= curuser->name %>.
+<% } %>
 <ul>
+	<% if(curuser){ %>
+	<li><a href="?delete=session">Log out</a></li>
+	<% }else{ %>
 	<li><a href="?new=user">Sign up</a></li>
 	<li><a href="?new=session">Log in</a></li>
+	<% } %>
 </ul>
 <h3>Latest posts</h3>
 <table border="1">