clean up cowbull, some docs

doc/2012-02-TF4/assignments.py

@@ -26,6 +26,10 @@ Course questions should be directed to the appropriate instructor:
 General questions about Tracer FIRE may be sent to
 Neale Pickett <neale@lanl.gov>
 
+Remember: the exercise network should be considered
+hostile!  Do not bring anything sensitive on your laptop,
+and make sure you back everything up.
+
 Looking forward to seeing you in Santa Fe next week,
 
 -- 

packages/cowbull/cowbull.mk

@@ -0,0 +1,19 @@
+COWBULL_PKGDIR = $(TARGET)/cowbull
+
+cowbull-install: cowbull-build
+	mkdir -p $(COWBULL_PKGDIR)
+
+	mkdir -p $(COWBULL_PKGDIR)/bin/
+	$(MAKE) -C packages/cowbull/src install DESTDIR=$(CURDIR)/$(COWBULL_PKGDIR)
+
+	$(call COPYTREE, packages/cowbull/service, $(COWBULL_PKGDIR)/service)
+	cp packages/cowbull/tokens.txt $(COWBULL_PKGDIR)/
+
+cowbull-clean:
+	rm -rf $(COWBULL_PKGDIR)
+	$(MAKE) -C packages/cowbull/src clean
+
+cowbull-build:
+	$(MAKE) -C packages/cowbull/src build
+
+PACKAGES += cowbull

packages/cowbull/service/cowbull/finish

@@ -0,0 +1,4 @@
+#! /bin/sh
+
+read IP < ip.txt
+ip addr del $IP dev eth0

packages/cowbull/service/cowbull/ip.txt

@@ -0,0 +1 @@
+fd84:b410:3441::ec6/64

packages/cowbull/service/cowbull/log/run

@@ -0,0 +1,3 @@
+#! /bin/sh
+
+exec svlogd -tt $PWD

packages/cowbull/service/cowbull/run

@@ -0,0 +1,7 @@
+#! /bin/sh -e
+
+exec 2>&1
+read IP < ip.txt
+ip addr add $IP dev eth0 || true
+
+exec setuidgid nobody /opt/cowbull/bin/cowd < /opt/cowbull/tokens.txt

packages/cowbull/src/Makefile

@@ -1 +1,11 @@
+DESTDIR ?= /tmp
+
 all: cowd cowcli
+
+cowcli: CC=cc
+
+install: all
+	cp cowd cowcli $(DESTDIR)/bin/
+
+clean:
+	rm -f cowd cowcli

packages/cowbull/src/cowcli.c

@@ -9,10 +9,17 @@
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <sys/wait.h>
+#include <netdb.h>
 #include <fcntl.h>
 
 
-#define DEBUG
+#define NODEBUG
+
+#ifdef DEBUG
+#   define PORT 4444
+#else
+#   define PORT 44
+#endif
 
 int
 bind_port(int fd, const struct in6_addr *addr, uint16_t port)
@@ -86,7 +93,7 @@ main(int argc, char *argv[])
     long            answer = 0;
     int             sock;
     int             i;
-    struct in6_addr addr;
+    struct addrinfo *addr;
     uint32_t        token = 0;
     FILE            *in, *out;
 
@@ -94,20 +101,31 @@ main(int argc, char *argv[])
 
     signal(SIGCHLD, sigchld);
 
-    if (0 >= inet_pton(AF_INET6, argv[1], &addr)) {
+    if (argc < 2) {
-        fprintf(stderr, "invalid address: %s\n", argv[1]);
+        fprintf(stderr, "Usage: %s SERVER\n", argv[0]);
-        return EX_IOERR;
+        return EX_USAGE;
+    }
+
+    {
+        struct addrinfo hints = { 0 };
+
+        hints.ai_family = PF_INET6;
+        hints.ai_socktype = SOCK_DGRAM;
+        hints.ai_flags = AI_NUMERICHOST;
+
+        if (0 != getaddrinfo(argv[1], "3782", &hints, &addr)) {
+            perror("Resolving address");
+            return EX_IOERR;
+        }
     }
 
     /*
      * Set up socket 
      */
     sock = socket(AF_INET6, SOCK_DGRAM, 0);
-    if (-1 == bind_port(sock, &in6addr_any, 44)) {
+    if (-1 == bind_port(sock, &in6addr_any, PORT)) {
         perror("Binding UDP port 44");
-#ifndef DEBUG
         return EX_IOERR;
-#endif
     }
 
     if (argv[2]) {
@@ -139,7 +157,7 @@ main(int argc, char *argv[])
         }
 
         /* Send the guess */
-        if (-1 == sendto(sock, &g, sizeof g, 0, &addr, sizeof addr)) {
+        if (-1 == sendto(sock, &g, sizeof g, 0, addr->ai_addr, addr->ai_addrlen)) {
             perror("Sending packet");
             return EX_IOERR;
         }
@@ -156,15 +174,20 @@ main(int argc, char *argv[])
                     return EX_IOERR;
                 case 1:
                     /* It's a score */
+                    printf("%02x\n", buf[0]);
+                    break;
                 case 4:
                     /* New game token */
+                    printf("NEW GAME\n");
+                    token = *((uint32_t *) buf);
+                    break;
                 default:
                     /* You win: this is your CTF token */
+                    buf[len] = 0;
+                    printf("A WINNER IS YOU: %s\n", buf);
+                    break;
             }
         }
-
-        /* parse result */
-        /* display result */
     }
 
     return 0;

packages/cowbull/src/cowd.c

@@ -14,6 +14,8 @@
 char            tokens[NTOKENS][TOKENLEN];
 int             ntokens;
 
+char *admonishment = "Try for fewer guesses next time!\n";
+
 struct state {
     time_t          death;
     uint16_t        answer;
@@ -58,10 +60,14 @@ new_game(int sock, time_t now, struct sockaddr_in6 *from,
             for (i = 0; i < 4; i += 1) {
                 s->answer = (s->answer << 4) | ((random() % 6) + 1);
             }
+
+            g.token = s->answer;
             break;
         }
     }
 
+    printf("=%02x\n", g.token);
+
     if (g.offset < NSTATES) {
         sendto(sock, &g, sizeof(g), 0, (struct sockaddr *) from, fromlen);
     }
@@ -103,7 +109,7 @@ loop(int sock)
     }
     cur = &states[g.offset];
 
-    if ((g.token != cur->answer) || /* Wrong token? */
+    if ((g.token != cur->answer) ||     /* Wrong token? */
         (cur->death < now) ||   /* Old game? */
         (cur->guesses++ > 100)) {       /* Too dumb? */
         /*
@@ -112,8 +118,8 @@ loop(int sock)
         new_game(sock, now, &from, fromlen);
         return;
     } else {
-        uint8_t         reply;
+        uint8_t         reply = 0;
-        int i;
+        int             i;
 
         for (i = 0; i < 4; i += 1) {
             int             s = (g.guess >> (i * 4)) & 0xf;
@@ -127,16 +133,22 @@ loop(int sock)
                 reply += 0x01;
             }
         }
+        printf("%02x ? %02x\n", g.guess, reply);
 
         if (reply == 0x40) {
-            if (cur->guesses > ntokens) {
+            char *r;
-                sendto(sock, tokens[cur->guesses],
+            
-                       strlen(tokens[cur->guesses]), 0,
+            if (cur->guesses <= ntokens) {
-                       (struct sockaddr *) &from, fromlen);
+                r = tokens[cur->guesses - 1];
+            } else {
+                r = admonishment;
             }
+            sendto(sock, r, strlen(r) - 1, 0,
+                   (struct sockaddr *) &from, fromlen);
+            cur->death = 0;
         } else {
-            sendto(sock, &reply, sizeof reply, 0, (struct sockaddr *) &from,
+            sendto(sock, &reply, sizeof reply, 0,
-                   fromlen);
+                   (struct sockaddr *) &from, fromlen);
         }
     }
 }
@@ -144,7 +156,6 @@ loop(int sock)
 int
 main(int argc, char *argv[])
 {
-    long            answer = 0;
     int             sock;
     int             i;
     struct in6_addr addr;
@@ -180,10 +191,6 @@ main(int argc, char *argv[])
         return EX_IOERR;
     }
 
-    for (i = 0; i < 4; i += 1) {
-        answer = (answer << 4) | ((random() % 6) + 1);
-    }
-
     while (1) {
         loop(sock);
     }

packages/cowbull/tokens.txt

@@ -0,0 +1,10 @@
+moo:1000000:xikov-fybir-zurox
+moo:9:xukiv-hudyb-fesix
+moo:8:xecoh-nyfyh-degix
+moo:7:xihap-synik-gesix
+moo:6:xegek-rulyz-polux
+moo:5:xitiz-fokel-radix
+moo:4:xuzif-gakit-fogyx
+moo:3:xisav-nodob-besex
+moo:2:xumol-peker-pibox
+moo:1:xilom-zosyk-cavux

packages/cowbull/www/moo.html

@@ -0,0 +1,91 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>Welcome</title>
+        <link rel="stylesheet" href="../ctf.css" type="text/css">
+    </head>
+    <body>
+        <h1>Moo.</h1>
+        <p>
+           You are trying to guess a 4-nybble sequence.  Each nybble will have
+           either 1 or 2 bits set, and the highest bit will never be set.  The
+           game server will tell you how many nybbles in each guess were correct,
+           and how many had one correct bit.  It does not tell you which
+           positions.
+        </p>
+
+        <h2>The Cow Client</h2>
+
+        <p>
+            <a href="cowcli">Download the client</a>
+        </p>
+
+        <p>
+            The client connects to the Cow server running on the IPv6
+            address provided in argument 1.  The client reads a guess
+            in the form of 4 ASCII numerals, and prints the number of
+            correct nybbles followed by the number of nybbles with one
+            correct bit.
+        </p>
+
+        <p>
+            Here is an example of a session:
+        </p>
+
+<pre>
+1111
+12
+2222
+10
+4444
+02
+4244
+12
+1244
+22
+1255
+moo:xylep-radar-nanox
+</pre>
+
+        <p>
+            You can use a program like <samp>socat</samp> to connect
+            the client to a logic program you write:
+        </p>
+<pre>
+socat EXEC:"./cowcli fd84:b410:3441::ec6" EXEC:./mysolution
+</pre>
+
+        <p>
+            This will allow your program to read and write from stdio
+            of the client program.
+        </p>
+
+
+        <h2>The Cow Protocol</h2>
+
+        <p>
+            cowd runs on port 3782 on fd84:b410:3441::ec6.
+        </p>
+
+        <p>
+            The client always sends 6 octets.  To request a new session, it sends
+            all zeroes.  Otherwise it sends the 4-octet game identifier provided
+            by the server, concatenated with a 2-octet guess.
+        </p>
+
+        <p>
+            The server will respond with a new game identifier (4 octets) to a new
+            game request or if the game requested is too old.  If a guess is
+            incorrect, the server will respond with either a 1-octet score in
+            which the high nybble is the number of correct nybbles in the guess,
+            and the low nybble is the number of nybbles in the guess with one
+            correct bit.  If a guess is correct, the server will respond with a
+            token of length 5 octets or more.
+        </p>
+
+        <p>
+            There are multiple tokens, one per number of guesses used, up to
+            some maximum number of guesses defined per server instance.
+        </p>
+    </body>
+</html>

packages/mcp/src/puzzler.cgi.c

@@ -61,11 +61,6 @@ main(int argc, char *argv[])
     char needle[400];
 
     my_snprintf(needle, sizeof(needle), "%ld %s", points, answer);
-  {
-    FILE *f = fopen("/tmp/form", "w");
-    fprintf(f, "%s\n%s\n", answer, needle);
-    fclose(f);
-  }
 
     if (! fgrepx(needle,
                  package_path("%s/answers.txt", category))) {

packages/rlyeh/service/rlyeh/ip.txt

@@ -1 +1 @@
-10.0.0.28/24
+fd84:b410:3441::b33b/64

packages/rlyeh/service/rlyeh/run

@@ -2,7 +2,7 @@
 
 exec 2>&1
 read IP < ip.txt
-ip addr add $IP label eth0:rlyeh dev eth0
+ip addr add $IP label eth0:rlyeh dev eth0 || true
 
 dir=/var/lib/ctf/rlyeh
 install -o nobody -d $dir