git-svn-id: https://svn.testnett.uninett.no/radsecproxy/trunk@2 e88ac4ed-0b26-0410-9574-a7f39faa03bf

4 files changed, 1315 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..a7982bd
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,9 @@
+CFLAGS = -g -Wall -pthread
+LDFLAGS = -lssl
+
+all: radsecproxy
+
+radsecproxy: util.o
+
+clean:
+	rm -f util.o radsecproxy
diff --git a/radsecproxy.c b/radsecproxy.c
new file mode 100644
index 0000000..8bf77bf
--- /dev/null
+++ b/radsecproxy.c
@@ -0,0 +1,1091 @@
+/*
+ * Copyright (C) 2006 Stig Venaas <venaas@uninett.no>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+/* BUGS:
+ * peers can not yet be specified with literal IPv6 addresses due to port syntax
+ */
+
+/* TODO:
+ * Among other things:
+ * timer based client retrans or maybe no retrans and just a timer...
+ * make our server ignore client retrans?
+ * tls keep alives
+ * routing based on id....
+ * tls certificate validation
+*/
+
+/* For UDP there is one server instance consisting of udpserverrd and udpserverth
+ *              rd is responsible for init and launching wr
+ * For TLS there is a server instance that launches tlsserverrd for each TLS peer
+ *          each tlsserverrd launches tlsserverwr
+ * For each UDP/TLS peer there is clientrd and clientwr, clientwr is responsible
+ *          for init and launching rd
+ *
+ * serverrd will receive a request, processes it and puts it in the requestq of
+ *          the appropriate clientwr
+ * clientwr monitors its requestq and sends requests
+ * clientrd looks for responses, processes them and puts them in the replyq of
+ *          the peer the request came from
+ * serverwr monitors its reply and sends replies
+ *
+ * In addition to the main thread, we have:
+ * If UDP peers are configured, there will be 2 + 2 * #peers UDP threads
+ * If TLS peers are configured, there will initially be 2 * #peers TLS threads
+ * For each TLS peer connecting to us there will be 2 more TLS threads
+ *       This is only for connected peers
+ * Example: With 3 UDP peer and 30 TLS peers, there will be a max of
+ *          1 + (2 + 2 * 3) + (2 * 30) + (2 * 30) = 129 threads
+*/
+
+#include <netdb.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <openssl/ssl.h>
+#include <openssl/rand.h>
+#include <openssl/err.h>
+#include <openssl/md5.h>
+#include "radsecproxy.h"
+
+static struct peer peers[MAX_PEERS];
+static int peer_count = 0;
+
+static struct replyq udp_server_replyq;
+static int udp_server_sock = -1;
+static char *udp_server_port = DEFAULT_UDP_PORT;
+static pthread_mutex_t *ssl_locks;
+static long *ssl_lock_count;
+static SSL_CTX *ssl_ctx_cl;
+extern int optind;
+extern char *optarg;
+
+/* callbacks for making OpenSSL thread safe */
+unsigned long ssl_thread_id() {
+        return (unsigned long)pthread_self();
+};
+
+void ssl_locking_callback(int mode, int type, const char *file, int line) {
+    if (mode & CRYPTO_LOCK) {
+	pthread_mutex_lock(&ssl_locks[type]);
+	ssl_lock_count[type]++;
+    } else
+	pthread_mutex_unlock(&ssl_locks[type]);
+}
+
+void ssl_locks_setup() {
+    int i;
+
+    ssl_locks = malloc(CRYPTO_num_locks() * sizeof(pthread_mutex_t));
+    ssl_lock_count = OPENSSL_malloc(CRYPTO_num_locks() * sizeof(long));
+    for (i = 0; i < CRYPTO_num_locks(); i++) {
+	ssl_lock_count[i] = 0;
+	pthread_mutex_init(&ssl_locks[i], NULL);
+    }
+
+    CRYPTO_set_id_callback(ssl_thread_id);
+    CRYPTO_set_locking_callback(ssl_locking_callback);
+}
+
+int resolvepeer(struct peer *peer) {
+    struct addrinfo hints;
+    
+    pthread_mutex_lock(&peer->lock);
+    if (peer->addrinfo) {
+	/* assume we should re-resolve */
+	freeaddrinfo(peer->addrinfo);
+	peer->addrinfo = NULL;
+    }
+    
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_socktype = (peer->type == 'T' ? SOCK_STREAM : SOCK_DGRAM);
+    hints.ai_family = AF_UNSPEC;
+    if (getaddrinfo(peer->host, peer->port, &hints, &peer->addrinfo)) {
+	err("resolvepeer: can't resolve %s port %s", peer->host, peer->port);
+	peer->addrinfo = NULL; /* probably don't need this */
+	pthread_mutex_unlock(&peer->lock);
+	return 0;
+    }
+    pthread_mutex_unlock(&peer->lock);
+    return 1;
+}	  
+
+int connecttopeer(struct peer *peer) {
+    int s;
+    struct addrinfo *res;
+    
+    if (!peer->addrinfo) {
+	resolvepeer(peer);
+	if (!peer->addrinfo) {
+	    printf("connecttopeer: can't resolve %s into address to connect to\n", peer->host);
+	    return -1;
+	}
+    }
+
+    for (res = peer->addrinfo; res; res = res->ai_next) {
+        s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+        if (s < 0) {
+            err("connecttopeer: socket failed");
+            continue;
+        }
+        if (connect(s, res->ai_addr, res->ai_addrlen) == 0)
+            break;
+        err("connecttopeer: connect failed");
+        close(s);
+        s = -1;
+    }
+    return s;
+}	  
+
+/* returns the peer with matching address, or NULL */
+/* if peer argument is not NULL, we only check that one peer */
+struct peer *find_peer(char type, struct sockaddr *addr, struct peer *peer) {
+    struct sockaddr_in6 *sa6;
+    struct in_addr *a4 = NULL;
+    struct peer *p;
+    int i;
+    struct addrinfo *res;
+
+    if (addr->sa_family == AF_INET6) {
+        sa6 = (struct sockaddr_in6 *)addr;
+        if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr))
+            a4 = (struct in_addr *)&sa6->sin6_addr.s6_addr[12];
+    } else
+	a4 = &((struct sockaddr_in *)addr)->sin_addr;
+
+    p = (peer ? peer : peers);
+    for (i = 0; i < peer_count; i++) {
+	if (p->type == type)
+	    for (res = p->addrinfo; res; res = res->ai_next)
+		if ((a4 && res->ai_family == AF_INET &&
+		     !memcmp(a4, &((struct sockaddr_in *)res->ai_addr)->sin_addr, 4)) ||
+		    (res->ai_family == AF_INET6 &&
+		     !memcmp(&sa6->sin6_addr, &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr, 16)))
+		    return p;
+	if (peer)
+	    break;
+	p++;
+    }
+    return NULL;
+}
+
+/* if *peer == NULL we return who we received from, else require it to be from peer */
+/* return from in sa if not NULL */
+unsigned char *radudpget(int s, struct peer **peer, struct sockaddr_storage *sa) {
+    int cnt, len;
+    struct peer *f;
+    unsigned char buf[65536], *rad;
+    struct sockaddr_storage from;
+    socklen_t fromlen = sizeof(from);
+
+    for (;;) {
+	cnt = recvfrom(s, buf, sizeof(buf), 0, (struct sockaddr *)&from, &fromlen);
+	if (cnt == -1) {
+	    err("radudpget: recv failed");
+	    continue;
+	}
+	printf("radudpget: got %d bytes from %s\n", cnt, addr2string((struct sockaddr *)&from, fromlen));
+
+	if (cnt < 20) {
+	    printf("radudpget: packet too small\n");
+	    continue;
+	}
+    
+	len = RADLEN(buf);
+
+	if (cnt < len) {
+	    printf("radudpget: packet smaller than length field in radius header\n");
+	    continue;
+	}
+	if (cnt > len)
+	    printf("radudpget: packet was padded with %d bytes\n", cnt - len);
+
+	f = find_peer('U', (struct sockaddr *)&from, *peer);
+	if (!f) {
+	    printf("radudpget: got packet from wrong or unknown UDP peer, ignoring\n");
+	    continue;
+	}
+
+	rad = malloc(len);
+	if (rad)
+	    break;
+	err("radudpget: malloc failed");
+    }
+    memcpy(rad, buf, len);
+    *peer = f; /* only need this if *peer == NULL, but if not NULL *peer == f here */
+    if (sa)
+	*sa = from;
+    return rad;
+}
+
+void tlsconnect(struct peer *peer, int oldsock, char *text) {
+    unsigned int sleeptime, try = 0;
+    
+    pthread_mutex_lock(&peer->lock);
+    if (peer->sockcl != oldsock) {
+	/* already reconnected, nothing to do */
+	printf("reconnect: seems already reconnected\n");
+	pthread_mutex_unlock(&peer->lock);
+	return;
+    }
+
+    printf("tlsconnect %d %s\n", oldsock, text);
+    sleep(1);
+    for (;;) {
+	printf("tlsconnect: trying to open TLS connection to %s port %s\n", peer->host, peer->port);
+	if ((peer->sockcl = connecttopeer(peer)) >= 0)
+	    break;
+	try++;
+	if (try < 6)
+	    sleeptime = 10;
+	else if (try < 20)
+	    sleeptime = 60;
+	else
+	    sleeptime = 900;
+	/* should possibly re-resolve host addresses at some point */
+	printf("tlsconnect: can't connect, retry #%d in %ds\n", try, sleeptime);
+	sleep(sleeptime);
+    }
+	
+    SSL_free(peer->sslcl);
+    peer->sslcl = SSL_new(ssl_ctx_cl);
+    SSL_set_fd(peer->sslcl, peer->sockcl);
+    /* must close oldsock after get new socket so that they are always different */
+    if (oldsock >= 0)
+	close(oldsock);
+    SSL_connect(peer->sslcl);
+    printf("tlsconnect: TLS connection to %s port %s up\n", peer->host, peer->port);
+    pthread_mutex_unlock(&peer->lock);
+}
+
+unsigned char *radtlsget(SSL *ssl) {
+    int cnt, total, len;
+    unsigned char buf[4], *rad;
+
+    for (;;) {
+	for (total = 0; total < 4; total += cnt) {
+	    cnt = SSL_read(ssl, buf + total, 4 - total);
+	    if (cnt <= 0) {
+		printf("radtlsget: connection lost\n");
+		return NULL;
+	    }
+	}
+
+	len = RADLEN(buf);
+	rad = malloc(len);
+	if (!rad) {
+	    err("radtlsget: malloc failed");
+	    continue;
+	}
+	memcpy(rad, buf, 4);
+
+	for (; total < len; total += cnt) {
+	    cnt = SSL_read(ssl, rad + total, len - total);
+	    if (cnt <= 0) {
+		printf("radtlsget: connection lost\n");
+		free(rad);
+		return NULL;
+	    }
+	}
+    
+	if (total >= 20)
+	    break;
+	
+	free(rad);
+	printf("radtlsget: packet smaller than minimum radius size\n");
+    }
+    
+    printf("radtlsget: got %d bytes\n", total);
+    return rad;
+}
+
+int clientradput(struct peer *peer, unsigned char *rad) {
+    int cnt, s;
+    size_t len;
+    unsigned long error;
+
+    len = RADLEN(rad);
+    if (peer->type == 'U') {
+	if (send(peer->sockcl, rad, len, 0) >= 0) {
+	    printf("clienradput: sent UDP of length %d to %s port %s\n", len, peer->host, peer->port);
+	    return 1;
+	}
+	err("clientradput: send failed");
+	return 0;
+    }
+
+    s = peer->sockcl;
+    while ((cnt = SSL_write(peer->sslcl, rad, len)) <= 0) {
+	while ((error = ERR_get_error()))
+	    err("clientwr: TLS: %s", ERR_error_string(error, NULL));
+	tlsconnect(peer, s, "clientradput");
+	s = peer->sockcl;
+    }
+	   
+    printf("clientradput: Sent %d bytes, Radius packet of length %d to TLS peer %s\n",
+	   cnt, len, peer->host);
+    return 1;
+}
+
+int radsign(unsigned char *rad, unsigned char *sec) {
+    static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+    static unsigned char first = 1;
+    static EVP_MD_CTX mdctx;
+    unsigned int md_len;
+    int result;
+    
+    pthread_mutex_lock(&lock);
+    if (first) {
+	EVP_MD_CTX_init(&mdctx);
+	first = 0;
+    }
+
+    result = (EVP_DigestInit_ex(&mdctx, EVP_md5(), NULL) &&
+	EVP_DigestUpdate(&mdctx, rad, RADLEN(rad)) &&
+	EVP_DigestUpdate(&mdctx, sec, strlen(sec)) &&
+	EVP_DigestFinal_ex(&mdctx, rad + 4, &md_len) &&
+	md_len == 16);
+    pthread_mutex_unlock(&lock);
+    return result;
+}
+
+int validauth(unsigned char *rad, unsigned char *reqauth, unsigned char *sec) {
+    static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+    static unsigned char first = 1;
+    static EVP_MD_CTX mdctx;
+    unsigned char hash[EVP_MAX_MD_SIZE];
+    unsigned int len;
+    int result;
+    
+    pthread_mutex_lock(&lock);
+    if (first) {
+	EVP_MD_CTX_init(&mdctx);
+	first = 0;
+    }
+
+    len = RADLEN(rad);
+    
+    result = (EVP_DigestInit_ex(&mdctx, EVP_md5(), NULL) &&
+	      EVP_DigestUpdate(&mdctx, rad, 4) &&
+	      EVP_DigestUpdate(&mdctx, reqauth, 16) &&
+	      (len <= 20 || EVP_DigestUpdate(&mdctx, rad + 20, len - 20)) &&
+	      EVP_DigestUpdate(&mdctx, sec, strlen(sec)) &&
+	      EVP_DigestFinal_ex(&mdctx, hash, &len) &&
+	      len == 16 &&
+	      !memcmp(hash, rad + 4, 16));
+    pthread_mutex_unlock(&lock);
+    return result;
+}
+	      
+void sendrq(struct peer *to, struct peer *from, struct request *rq) {
+    int i;
+
+    pthread_mutex_lock(&to->newrq_mutex);
+    for (i = 0; i < MAX_REQUESTS; i++)
+	if (!to->requests[i].buf)
+	    break;
+    if (i == MAX_REQUESTS) {
+	printf("No room in queue, dropping request\n");
+	pthread_mutex_unlock(&to->newrq_mutex);
+	return;
+    }
+    
+    rq->buf[1] = (char)i;
+    to->requests[i] = *rq;
+
+    if (!to->newrq) {
+	to->newrq = 1;
+	printf("signalling client writer\n");
+	pthread_cond_signal(&to->newrq_cond);
+    }
+    pthread_mutex_unlock(&to->newrq_mutex);
+}
+
+void sendreply(struct peer *to, struct peer *from, char *buf, struct sockaddr_storage *tosa) {
+    struct replyq *replyq = to->replyq;
+    
+    pthread_mutex_lock(&replyq->count_mutex);
+    if (replyq->count == replyq->size) {
+	printf("No room in queue, dropping request\n");
+	pthread_mutex_unlock(&replyq->count_mutex);
+	return;
+    }
+
+    replyq->replies[replyq->count].buf = buf;
+    if (tosa)
+	replyq->replies[replyq->count].tosa = *tosa;
+    replyq->count++;
+
+    if (replyq->count == 1) {
+	printf("signalling client writer\n");
+	pthread_cond_signal(&replyq->count_cond);
+    }
+    pthread_mutex_unlock(&replyq->count_mutex);
+}
+
+int pwdcrypt(uint8_t *plain, uint8_t *enc, uint8_t enclen, uint8_t *shared, uint8_t sharedlen,
+		uint8_t *auth) {
+    static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+    static unsigned char first = 1;
+    static EVP_MD_CTX mdctx;
+    unsigned char hash[EVP_MAX_MD_SIZE], *input;
+    unsigned int md_len;
+    uint8_t i, offset = 0;
+    
+    pthread_mutex_lock(&lock);
+    if (first) {
+	EVP_MD_CTX_init(&mdctx);
+	first = 0;
+    }
+
+    input = auth;
+    for (;;) {
+	if (!EVP_DigestInit_ex(&mdctx, EVP_md5(), NULL) ||
+	    !EVP_DigestUpdate(&mdctx, shared, sharedlen) ||
+	    !EVP_DigestUpdate(&mdctx, input, 16) ||
+	    !EVP_DigestFinal_ex(&mdctx, hash, &md_len) ||
+	    md_len != 16) {
+	    pthread_mutex_unlock(&lock);
+	    return 0;
+	}
+	for (i = 0; i < 16; i++)
+	    plain[offset + i] = hash[i] ^ enc[offset + i];
+	offset += 16;
+	if (offset == enclen)
+	    break;
+	input = enc + offset - 16;
+    }
+    pthread_mutex_unlock(&lock);
+    return 1;
+}
+
+struct peer *radsrv(struct request *rq, char *buf, struct peer *from) {
+    uint8_t code, id, *auth, *attr, *usernameattr = NULL, *userpwdattr = NULL, pwd[128], pwdlen;
+    int i;
+    uint16_t len;
+    int left;
+    struct peer *to;
+    unsigned char newauth[16];
+    
+    code = *(uint8_t *)buf;
+    id = *(uint8_t *)(buf + 1);
+    len = RADLEN(buf);
+    auth = (uint8_t *)(buf + 4);
+
+    printf("radsrv: code %d, id %d, length %d\n", code, id, len);
+    
+    if (code != RAD_Access_Request) {
+	printf("radsrv: server currently accepts only access-requests, ignoring\n");
+	return NULL;
+    }
+
+    left = len - 20;
+    attr = buf + 20;
+    
+    while (left > 1) {
+	left -= attr[RAD_Attr_Length];
+	if (left < 0) {
+	    printf("radsrv: attribute length exceeds packet length, ignoring packet\n");
+	    return NULL;
+	}
+	switch (attr[RAD_Attr_Type]) {
+	case RAD_Attr_User_Name:
+	    usernameattr = attr;
+	    break;
+	case RAD_Attr_User_Password:
+	    userpwdattr = attr;
+	    break;
+	}
+	attr += attr[RAD_Attr_Length];
+    }
+    if (left)
+	printf("radsrv: malformed packet? remaining byte after last attribute\n");
+
+    if (usernameattr) {
+	printf("radsrv: Username: ");
+	for (i = 0; i < usernameattr[RAD_Attr_Length]; i++)
+	    printf("%c", usernameattr[RAD_Attr_Value + i]);
+	printf("\n");
+    }
+
+    /* find out where to send the packet, for now we send to first connected
+       TLS peer if UDP, and first UDP peer if TLS */
+    
+    i = peer_count;
+    switch (from->type) {
+    case 'U':
+	for (i = 0; i < peer_count; i++)
+	    if (peers[i].type == 'T' && peers[i].sockcl >= 0)
+		break;
+	break;
+    case 'T':
+	for (i = 0; i < peer_count; i++)
+	    if (peers[i].type == 'U')
+		break;
+	break;
+    }
+
+    if (i == peer_count) {
+	printf("radsrv: ignoring request, don't know where to send it\n");
+	return NULL;
+    }
+
+    to = &peers[i];
+    
+    if (!RAND_bytes(newauth, 16)) {
+	printf("radsrv: failed to generate random auth\n");
+	return NULL;
+    }
+
+    if (userpwdattr) {
+	printf("radsrv: found userpwdattr of length %d\n", userpwdattr[RAD_Attr_Length]);
+	pwdlen = userpwdattr[RAD_Attr_Length] - 2;
+	if (pwdlen < 16 || pwdlen > 128 || pwdlen % 16) {
+	    printf("radsrv: invalid user password length\n");
+	    return NULL;
+	}
+	
+	if (!pwdcrypt(pwd, &userpwdattr[RAD_Attr_Value], pwdlen, from->secret, strlen(from->secret), auth)) {
+	    printf("radsrv: cannot decrypt password\n");
+	    return NULL;
+	}
+	printf("radsrv: password: ");
+	for (i = 0; i < pwdlen; i++)
+	    printf("%02x ", pwd[i]);
+	printf("\n");
+	if (!pwdcrypt(&userpwdattr[RAD_Attr_Value], pwd, pwdlen, to->secret, strlen(to->secret), newauth)) {
+	    printf("radsrv: cannot encrypt password\n");
+	    return NULL;
+	}
+    }
+
+    rq->buf = buf;
+    rq->from = from;
+    rq->origid = id;
+    memcpy(rq->origauth, auth, 16);
+    memcpy(rq->buf + 4, newauth, 16);
+    return to;
+}
+
+void *clientrd(void *arg) {
+    struct peer *from, *peer = (struct peer *)arg;
+    int i, s;
+    unsigned char *buf;
+    struct sockaddr_storage fromsa;
+    
+    for (;;) {
+	s = peer->sockcl;
+	buf = (peer->type == 'U' ? radudpget(s, &peer, NULL) : radtlsget(peer->sslcl));
+	if (!buf && peer->type == 'T') {
+	    printf("retry in 60s\n");
+	    sleep(60); /* should have exponential backoff perhaps, better do it inside radtlsget */
+	    tlsconnect(peer, s, "clientrd");
+	    continue;
+	}
+	
+	i = buf[1]; /* i is the id */
+
+	pthread_mutex_lock(&peer->newrq_mutex);
+	if (!peer->requests[i].buf || !peer->requests[i].tries) {
+	    pthread_mutex_unlock(&peer->newrq_mutex);
+	    printf("clientrd: no matching request sent with this id, ignoring\n");
+	    continue;
+	}
+        
+	if (peer->requests[i].received) {
+	    pthread_mutex_unlock(&peer->newrq_mutex);
+	    printf("clientrd: already received, ignoring\n");
+	    continue;
+	}
+
+	if (!validauth(buf, peer->requests[i].buf + 4, peer->secret)) {
+	    pthread_mutex_unlock(&peer->newrq_mutex);
+	    printf("clientrd: invalid auth, ignoring\n");
+	    continue;
+	}
+
+	/* once we set received = 1, requests[i] may be reused */
+	buf[1] = (char)peer->requests[i].origid;
+	memcpy(buf + 4, peer->requests[i].origauth, 16);
+	from = peer->requests[i].from;
+	if (from->type == 'U')
+	    fromsa = peer->requests[i].fromsa;
+	peer->requests[i].received = 1;
+	pthread_mutex_unlock(&peer->newrq_mutex);
+
+	if (!radsign(buf, from->secret)) {
+	    printf("clientrd: failed to sign message\n");
+	    continue;
+	}
+	
+	printf("clientrd: giving packet back to where it came from\n");
+	sendreply(from, peer, buf, from->type == 'U' ? &fromsa : NULL);
+    }
+}
+
+void *clientwr(void *arg) {
+    struct peer *peer = (struct peer *)arg;
+    pthread_t clientrdth;
+    int i;
+
+    if (peer->type == 'U') {
+	if ((peer->sockcl = connecttopeer(peer)) < 0) {
+	    printf("clientwr: connecttopeer failed\n");
+	    exit(1);
+	}
+    } else
+	tlsconnect(peer, -1, "new client");
+    
+    if (pthread_create(&clientrdth, NULL, clientrd, (void *)peer))
+	errx("clientwr: pthread_create failed");
+
+    for (;;) {
+	pthread_mutex_lock(&peer->newrq_mutex);
+	while (!peer->newrq) {
+	    printf("clientwr: waiting for signal\n");
+	    pthread_cond_wait(&peer->newrq_cond, &peer->newrq_mutex);
+	    printf("clientwr: got signal\n");
+	}
+	peer->newrq = 0;
+	pthread_mutex_unlock(&peer->newrq_mutex);
+	       
+	for (i = 0; i < MAX_REQUESTS; i++) {
+	    pthread_mutex_lock(&peer->newrq_mutex);
+	    while (!peer->requests[i].buf && i < MAX_REQUESTS)
+		i++;
+	    if (i == MAX_REQUESTS) {
+		pthread_mutex_unlock(&peer->newrq_mutex);
+		break;
+	    }
+
+	    /* already received or too many tries */
+            if (peer->requests[i].received || peer->requests[i].tries > 2) {
+                free(peer->requests[i].buf);
+                /* setting this to NULL means that it can be reused */
+                peer->requests[i].buf = NULL;
+                pthread_mutex_unlock(&peer->newrq_mutex);
+                continue;
+            }
+            pthread_mutex_unlock(&peer->newrq_mutex);
+            
+            peer->requests[i].tries++;
+	    clientradput(peer, peer->requests[i].buf);
+	}
+    }
+    /* should do more work to maintain TLS connections, keepalives etc */
+}
+
+void *udpserverwr(void *arg) {
+    struct replyq *replyq = &udp_server_replyq;
+    struct reply *reply = replyq->replies;
+    
+    pthread_mutex_lock(&replyq->count_mutex);
+    for (;;) {
+	while (!replyq->count) {
+	    printf("udp server writer, waiting for signal\n");
+	    pthread_cond_wait(&replyq->count_cond, &replyq->count_mutex);
+	    printf("udp server writer, got signal\n");
+	}
+	pthread_mutex_unlock(&replyq->count_mutex);
+	
+	if (sendto(udp_server_sock, reply->buf, RADLEN(reply->buf), 0,
+		   (struct sockaddr *)&reply->tosa, SOCKADDR_SIZE(reply->tosa)) < 0)
+	    err("sendudp: send failed");
+	free(reply->buf);
+	
+	pthread_mutex_lock(&replyq->count_mutex);
+	replyq->count--;
+	memmove(replyq->replies, replyq->replies + 1,
+		replyq->count * sizeof(struct reply));
+    }
+}
+
+void *udpserverrd(void *arg) {
+    struct request rq;
+    unsigned char *buf;
+    struct peer *to, *fr;
+    pthread_t udpserverwrth;
+    
+    if ((udp_server_sock = bindport(SOCK_DGRAM, udp_server_port)) < 0) {
+        printf("udpserverrd: socket/bind failed\n");
+	exit(1);
+    }
+    printf("udpserverrd: listening on UDP port %s\n", udp_server_port);
+
+    if (pthread_create(&udpserverwrth, NULL, udpserverwr, NULL))
+	errx("pthread_create failed");
+    
+    for (;;) {
+	fr = NULL;
+	memset(&rq, 0, sizeof(struct request));
+	buf = radudpget(udp_server_sock, &fr, &rq.fromsa);
+	to = radsrv(&rq, buf, fr);
+	if (!to) {
+	    printf("udpserverrd: ignoring request, no place to send it\n");
+	    continue;
+	}
+	sendrq(to, fr, &rq);
+    }
+}
+
+void *tlsserverwr(void *arg) {
+    int cnt;
+    unsigned long error;
+    struct peer *peer = (struct peer *)arg;
+    struct replyq *replyq;
+    
+    pthread_mutex_lock(&peer->replycount_mutex);
+    for (;;) {
+	replyq = peer->replyq;
+	while (!replyq->count) {
+	    printf("tls server writer, waiting for signal\n");
+	    pthread_cond_wait(&replyq->count_cond, &replyq->count_mutex);
+	    printf("tls server writer, got signal\n");
+	}
+	pthread_mutex_unlock(&replyq->count_mutex);
+	cnt = SSL_write(peer->sslsrv, replyq->replies->buf, RADLEN(replyq->replies->buf));
+	if (cnt > 0)
+	    printf("tlsserverwr: Sent %d bytes, Radius packet of length %d\n",
+		   cnt, RADLEN(replyq->replies->buf));
+	else
+	    while ((error = ERR_get_error()))
+		err("tlsserverwr: SSL: %s", ERR_error_string(error, NULL));
+	free(replyq->replies->buf);
+
+	pthread_mutex_lock(&replyq->count_mutex);
+	replyq->count--;
+	memmove(replyq->replies, replyq->replies + 1, replyq->count * sizeof(struct reply));
+    }
+}
+
+void *tlsserverrd(void *arg) {
+    struct request rq;
+    char unsigned *buf;
+    unsigned long error;
+    struct peer *to;
+    int s;
+    struct peer *peer = (struct peer *)arg;
+    pthread_t tlsserverwrth;
+
+    printf("tlsserverrd starting\n");
+    if (SSL_accept(peer->sslsrv) <= 0) {
+        while ((error = ERR_get_error()))
+            err("tlsserverrd: SSL: %s", ERR_error_string(error, NULL));
+        errx("accept failed, child exiting");
+    }
+
+    if (pthread_create(&tlsserverwrth, NULL, tlsserverwr, (void *)peer))
+	errx("pthread_create failed");
+    
+    for (;;) {
+	buf = radtlsget(peer->sslsrv);
+	if (!buf) {
+	    printf("tlsserverrd: connection lost\n");
+	    s = SSL_get_fd(peer->sslsrv);
+	    SSL_free(peer->sslsrv);
+	    peer->sslsrv = NULL;
+	    if (s >= 0)
+		close(s);
+	    pthread_exit(NULL);
+	}
+	printf("tlsserverrd: got Radius message from %s\n", peer->host);
+	memset(&rq, 0, sizeof(struct request));
+	to = radsrv(&rq, buf, peer);
+	if (!to) {
+	    printf("ignoring request, no place to send it\n");
+	    continue;
+	}
+	sendrq(to, peer, &rq);
+    }
+}
+
+int tlslistener(SSL_CTX *ssl_ctx) {
+    pthread_t tlsserverth;
+    int s, snew;
+    struct sockaddr_storage from;
+    size_t fromlen = sizeof(from);
+    struct peer *peer;
+
+    if ((s = bindport(SOCK_STREAM, DEFAULT_TLS_PORT)) < 0) {
+        printf("tlslistener: socket/bind failed\n");
+	exit(1);
+    }
+
+    listen(s, 0);
+    printf("listening for incoming TLS on port %s\n", DEFAULT_TLS_PORT);
+
+    for (;;) {
+	snew = accept(s, (struct sockaddr *)&from, &fromlen);
+	if (snew < 0)
+	    errx("accept failed");
+	printf("incoming TLS connection from %s\n", addr2string((struct sockaddr *)&from, fromlen));
+
+	peer = find_peer('T', (struct sockaddr *)&from, NULL);
+	if (!peer) {
+	    printf("ignoring request, not a known TLS peer\n");
+	    close(snew);
+	    continue;
+	}
+
+	if (peer->sslsrv) {
+	    printf("Ignoring incoming connection, already have one from this peer\n");
+	    close(snew);
+	    continue;
+	}
+	peer->sslsrv = SSL_new(ssl_ctx);
+	SSL_set_fd(peer->sslsrv, snew);
+	if (pthread_create(&tlsserverth, NULL, tlsserverrd, (void *)peer))
+	    errx("pthread_create failed");
+	
+	for (;;) {
+	    /* currently only one server thread, so just halt here */
+	    sleep(1000);
+	}
+    }
+    return 0;
+}
+
+char *parsehostport(char *s, char **host, char **port) {
+    char *p, *field;
+    int ipv6 = 0;
+
+    p = s;
+    // allow literal addresses and port, e.g. [2001:db8::1]:1812
+    if (*p == '[') {
+	p++;
+	field = p;
+	for (; *p && *p != ']' && *p != ' ' && *p != '\t' && *p != '\n'; p++);
+	if (*p != ']') {
+	    printf("no ] matching initial [\n");
+	    exit(1);
+	}
+	ipv6 = 1;
+    } else {
+	field = p;
+	for (; *p && *p != ':' && *p != ' ' && *p != '\t' && *p != '\n'; p++);
+    }
+    if (field == p) {
+	printf("missing host/address\n");
+	exit(1);
+    }
+    *host = malloc(p - field + 1);
+    if (!*host)
+	errx("malloc failed");
+    memcpy(*host, field, p - field);
+    (*host)[p - field] = '\0';
+    if (ipv6) {
+	p++;
+	if (*p && *p != ':' && *p != ' ' && *p != '\t' && *p != '\n') {
+	    printf("unexpected character after ]\n");
+	    exit(1);
+	}
+    }
+    if (*p == ':') {
+	    /* port number or service name is specified */;
+	    field = p++;
+	    for (; *p && *p != ' ' && *p != '\t' && *p != '\n'; p++);
+	    if (field == p) {
+		printf("syntax error, : but no following port\n");
+		exit(1);
+	    }
+	    *port = malloc(p - field + 1);
+	    if (!*port)
+		errx("malloc failed");
+	    memcpy(*port, field, p - field);
+	    (*port)[p - field ] = '\0';
+    } else
+        *port = NULL;
+    return p;
+}
+
+void getconfig(const char *filename) {
+    FILE *f;
+    char line[1024];
+    char *p, *field;
+    struct peer *peer;
+    
+    peer_count = 0;
+    
+    udp_server_replyq.replies = malloc(4 * MAX_REQUESTS * sizeof(struct reply));
+    if (!udp_server_replyq.replies)
+	errx("malloc failed");
+    udp_server_replyq.size = 4 * MAX_REQUESTS;
+    udp_server_replyq.count = 0;
+    pthread_mutex_init(&udp_server_replyq.count_mutex, NULL);
+    pthread_cond_init(&udp_server_replyq.count_cond, NULL);
+    
+    f = fopen(filename, "r");
+    if (!f)
+	errx("getconfig failed to open %s for reading", filename);
+
+    while (fgets(line, 1024, f) && peer_count < MAX_PEERS) {
+	peer = &peers[peer_count];
+	memset(peer, 0, sizeof(struct peer));
+
+	for (p = line; *p == ' ' || *p == '\t'; p++);
+	if (*p == '#' || *p == '\n')
+	    continue;
+	if (*p != 'U' && *p != 'T') {
+	    printf("server type must be U or T, got %c\n", *p);
+	    exit(1);
+	}
+	peer->type = *p;
+	for (p++; *p == ' ' || *p == '\t'; p++);
+	p = parsehostport(p, &peer->host, &peer->port);
+	if (!peer->port)
+	    peer->port = (peer->type == 'U' ? DEFAULT_UDP_PORT : DEFAULT_TLS_PORT);
+	for (; *p == ' ' || *p == '\t'; p++);
+	field = p;
+	for (; *p && *p != ' ' && *p != '\t' && *p != '\n'; p++);
+	if (field == p) {
+	    /* no secret set and end of line, line is complete if TLS */
+	    if (peer->type == 'U') {
+		printf("secret must be specified for UDP\n");
+		exit(1);
+	    }
+	    peer->secret = DEFAULT_TLS_SECRET;
+	} else {
+	    peer->secret = malloc(p - field + 1);
+	    if (!peer->secret)
+		errx("malloc failed");
+	    memcpy(peer->secret, field, p - field);
+	    peer->secret[p - field] = '\0';
+	    /* check that rest of line only white space */
+	    for (; *p == ' ' || *p == '\t'; p++);
+	    if (*p && *p != '\n') {
+		printf("max 3 fields per line, found a 4th\n");
+		exit(1);
+	    }
+	}
+	peer->sockcl = -1;
+	peer->sslsrv = NULL;
+	peer->sslcl = NULL;
+	pthread_mutex_init(&peer->lock, NULL);
+	if (!resolvepeer(peer)) {
+	    printf("failed to resolve host %s port %s, exiting\n", peer->host, peer->port);
+	    exit(1);
+	}
+	peer->requests = malloc(MAX_REQUESTS * sizeof(struct request));
+	if (!peer->requests)
+	    errx("malloc failed");
+	memset(peer->requests, 0, MAX_REQUESTS * sizeof(struct request));
+	peer->newrq = 0;
+	pthread_mutex_init(&peer->newrq_mutex, NULL);
+	pthread_cond_init(&peer->newrq_cond, NULL);
+
+	if (peer->type == 'U')
+	    peer->replyq = &udp_server_replyq;
+	else {
+	    peer->replyq = malloc(sizeof(struct replyq));
+	    if (!peer->replyq)
+		errx("malloc failed");
+	    peer->replyq->replies = malloc(MAX_REQUESTS * sizeof(struct reply));
+	    if (!peer->replyq->replies)
+		errx("malloc failed");
+	    peer->replyq->size = MAX_REQUESTS;
+	    peer->replyq->count = 0;
+	    pthread_mutex_init(&peer->replyq->count_mutex, NULL);
+	    pthread_cond_init(&peer->replyq->count_cond, NULL);
+	}
+	printf("got type %c, host %s, port %s, secret %s\n", peers[peer_count].type,
+	       peers[peer_count].host, peers[peer_count].port, peers[peer_count].secret);
+	peer_count++;
+    }
+    fclose(f);
+}
+
+void parseargs(int argc, char **argv) {
+    int c;
+
+    while ((c = getopt(argc, argv, "p:")) != -1) {
+	switch (c) {
+	case 'p':
+	    udp_server_port = optarg;
+	    break;
+	default:
+	    goto usage;
+	}
+    }
+
+    return;
+
+ usage:
+    printf("radsecproxy [ -p UDP-port ]\n");
+    exit(1);
+}
+	       
+int main(int argc, char **argv) {
+    SSL_CTX *ssl_ctx_srv;
+    unsigned long error;
+    pthread_t udpserverth;
+    pthread_attr_t joinable;
+    int i;
+    
+    parseargs(argc, argv);
+    getconfig("radsecproxy.conf");
+    
+    ssl_locks_setup();
+
+    pthread_attr_init(&joinable);
+    pthread_attr_setdetachstate(&joinable, PTHREAD_CREATE_JOINABLE);
+   
+    /* listen on UDP if at least one UDP peer */
+    
+    for (i = 0; i < peer_count; i++)
+	if (peers[i].type == 'U') {
+	    if (pthread_create(&udpserverth, &joinable, udpserverrd, NULL))
+		errx("pthread_create failed");
+	    break;
+	}
+    
+    for (i = 0; i < peer_count; i++)
+	if (peers[i].type == 'T')
+	    break;
+
+    if (i == peer_count) {
+	printf("No TLS peers defined, just doing UDP proxying\n");
+	/* just hang around doing nothing, anything to do here? */
+	pthread_join(udpserverth, NULL);
+	return 0;
+    }
+    
+    /* SSL setup */
+    SSL_load_error_strings();
+    SSL_library_init();
+
+    while (!RAND_status()) {
+	time_t t = time(NULL);
+	pid_t pid = getpid();
+	RAND_seed((unsigned char *)&t, sizeof(time_t));
+        RAND_seed((unsigned char *)&pid, sizeof(pid));
+    }
+    
+    /* initialise client part and start clients */
+    ssl_ctx_cl = SSL_CTX_new(TLSv1_client_method());
+    if (!ssl_ctx_cl)
+	errx("no ssl ctx");
+    
+    for (i = 0; i < peer_count; i++) {
+	if (pthread_create(&peers[i].clientth, NULL, clientwr, (void *)&peers[i]))
+	    errx("pthread_create failed");
+    }
+
+    /* setting up server/daemon part */
+    ssl_ctx_srv = SSL_CTX_new(TLSv1_server_method());
+    if (!ssl_ctx_srv)
+	errx("no ssl ctx");
+    if (!SSL_CTX_use_certificate_file(ssl_ctx_srv, "/tmp/server.pem", SSL_FILETYPE_PEM)) {
+        while ((error = ERR_get_error()))
+            err("SSL: %s", ERR_error_string(error, NULL));
+        errx("Failed to load certificate");
+    }
+    if (!SSL_CTX_use_PrivateKey_file(ssl_ctx_srv, "/tmp/server.key", SSL_FILETYPE_PEM)) {
+	while ((error = ERR_get_error()))
+	    err("SSL: %s", ERR_error_string(error, NULL));
+	errx("Failed to load private key");
+    }
+    return tlslistener(ssl_ctx_srv);
+}
diff --git a/radsecproxy.h b/radsecproxy.h
new file mode 100644
index 0000000..27cb1d4
--- /dev/null
+++ b/radsecproxy.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2006 Stig Venaas <venaas@uninett.no>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+#define RADLEN(x) ntohs(((uint16_t *)(x))[1])
+
+#define SOCKADDR_SIZE(addr) ((addr).ss_family == AF_INET ? \
+                            sizeof(struct sockaddr_in) : \
+                            sizeof(struct sockaddr_in6))
+
+#define MAX_PEERS 256
+/* MAX_REQUESTS is 256 due to Radius' 8 bit ID field */
+#define MAX_REQUESTS 256
+#define DEFAULT_TLS_SECRET "mysecret"
+#define DEFAULT_UDP_PORT "1812"
+#define DEFAULT_TLS_PORT "2083"
+
+#define RAD_Access_Request 1
+#define RAD_Access_Accept 2
+#define RAD_Access_Reject 3
+#define RAD_Accounting_Request 4
+#define RAD_Accounting_Response 5
+#define RAD_Access_Challenge 11
+#define RAD_Status_Server 12
+#define RAD_Status_Client 13
+
+#define RAD_Attr_User_Name 1
+#define RAD_Attr_User_Password 2
+
+#define RAD_Attr_Type 0
+#define RAD_Attr_Length 1
+#define RAD_Attr_Value 2
+
+/* requests that a client will send */
+struct request {
+    unsigned char *buf;
+    uint8_t tries;
+    uint8_t received;
+    struct timeval timeout;
+    struct peer *from;
+    uint8_t origid; /* used by servwr */
+    char origauth[16]; /* used by servwr */
+    struct sockaddr_storage fromsa; /* used by udpservwr */
+};
+
+/* replies that a server will send */
+struct reply {
+    unsigned char *buf;
+    struct sockaddr_storage tosa; /* used by udpservwr */
+};
+
+struct replyq {
+    struct reply *replies;
+    int count;
+    int size;
+    pthread_mutex_t count_mutex;
+    pthread_cond_t count_cond;
+};
+
+struct peer {
+    char type; /* U for UDP, T for TLS */
+    char *host;
+    char *port;
+    char *secret;
+    SSL *sslcl, *sslsrv;
+    pthread_mutex_t lock;
+    pthread_t clientth;
+    int sockcl;
+    struct addrinfo *addrinfo;
+    /* requests and newrq* are requests passed from servers to clients */
+    struct request *requests;
+    uint8_t newrq;
+    pthread_mutex_t newrq_mutex;
+    pthread_cond_t newrq_cond;
+    /* repl* are replies passed from clients to tls servers */
+    struct replyq *replyq;
+    int replycount;
+    pthread_mutex_t replycount_mutex;
+    pthread_cond_t replycount_cond;
+};
+
+void errx(char *format, ...);
+void err(char *format, ...);
+char *addr2string(struct sockaddr *addr, socklen_t len);
+int bindport(int type, char *port);
+int connectport(int type, char *host, char *port);
diff --git a/util.c b/util.c
new file mode 100644
index 0000000..4a2f1ad
--- /dev/null
+++ b/util.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2006 Stig Venaas <venaas@uninett.no>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdarg.h>
+
+void errx(char *format, ...) {
+    extern int errno;
+
+    va_list ap;
+    va_start(ap, format);
+    vfprintf(stderr, format, ap);
+    va_end(ap);
+    if (errno) {
+        fprintf(stderr, ": ");
+        perror(NULL);
+        fprintf(stderr, "errno=%d\n", errno);
+    } else
+        fprintf(stderr, "\n");
+    exit(1);
+}
+
+void err(char *format, ...) {
+    extern int errno;
+
+    va_list ap;
+    va_start(ap, format);
+    vfprintf(stderr, format, ap);
+    va_end(ap);
+    if (errno) {
+        fprintf(stderr, ": ");
+        perror(NULL);
+        fprintf(stderr, "errno=%d\n", errno);
+    } else
+        fprintf(stderr, "\n");
+}
+
+char *addr2string(struct sockaddr *addr, socklen_t len) {
+    struct sockaddr_in6 *sa6;
+    struct sockaddr_in sa4;
+    static char addr_buf[2][INET6_ADDRSTRLEN];
+    static int i = 0;
+    i = !i;
+    if (addr->sa_family == AF_INET6) {
+	sa6 = (struct sockaddr_in6 *)addr;
+	if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
+	    memset(&sa4, 0, sizeof(sa4));
+	    sa4.sin_family = AF_INET;
+	    sa4.sin_port = sa6->sin6_port;
+	    memcpy(&sa4.sin_addr, &sa6->sin6_addr.s6_addr[12], 4);
+	    addr = (struct sockaddr *)&sa4;
+	}
+    }
+    if (getnameinfo(addr, len, addr_buf[i], sizeof(addr_buf[i]),
+                    NULL, 0, NI_NUMERICHOST)) {
+        err("getnameinfo");
+        return NULL;
+    }
+    return addr_buf[i];
+}
+
+int bindport(int type, char *port) {
+    struct addrinfo hints, *res0, *res;
+    int s;
+    
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_socktype = type;
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_flags = AI_PASSIVE;
+
+    if (getaddrinfo(NULL, port, &hints, &res0) != 0) {
+        err("bindport: can't resolve port %s", port);
+	return -1;
+    }
+    for (res = res0; res; res = res->ai_next) {
+        s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+        if (s >= 0) {
+            if (bind(s, res->ai_addr, res->ai_addrlen) == 0)
+                break;
+            close(s);
+            s = -1;
+        }
+    }
+    freeaddrinfo(res0);
+    return s;
+}
+
+int connectport(int type, char *host, char *port) {
+    struct addrinfo hints, *res0, *res;
+    int s;
+    
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_socktype = type;
+    hints.ai_family = AF_UNSPEC;
+
+    if (getaddrinfo(host, port, &hints, &res0) != 0) {
+        err("connectport: can't resolve host %s port %s", host, port);
+	return -1;
+    }
+
+    for (res = res0; res; res = res->ai_next) {
+	s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+	if (s < 0) {
+	    err("connectport: socket failed");
+	    continue;
+	}
+	if (connect(s, res->ai_addr, res->ai_addrlen) == 0)
+	    break;
+	err("connectport: connect failed");
+	close(s);
+	s = -1;
+    }
+    freeaddrinfo(res0);
+    return s;
+}