X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/9bc9ec99e68baaa0778ca500f488a5887e0fd5ec..c1d1c2a8c4f22c3911d392393072327b0e319c5e:/radius.c?ds=sidebyside

diff --git a/radius.c b/radius.c
index 60b97a4..8481561 100644
--- a/radius.c
+++ b/radius.c
@@ -1,7 +1,5 @@
 // L2TPNS Radius Stuff
 
-char const *cvs_id_radius = "$Id: radius.c,v 1.52 2006/07/01 12:40:17 bodea Exp $";
-
 #include <time.h>
 #include <stdio.h>
 #include <sys/types.h>
@@ -13,6 +11,7 @@ char const *cvs_id_radius = "$Id: radius.c,v 1.52 2006/07/01 12:40:17 bodea Exp
 #include <ctype.h>
 #include <netinet/in.h>
 #include <errno.h>
+
 #include "md5.h"
 #include "constants.h"
 #include "l2tpns.h"
@@ -20,6 +19,9 @@ char const *cvs_id_radius = "$Id: radius.c,v 1.52 2006/07/01 12:40:17 bodea Exp
 #include "util.h"
 #include "cluster.h"
 
+#include "l2tplac.h"
+#include "pppoe.h"
+
 extern radiust *radius;
 extern sessiont *session;
 extern tunnelt *tunnel;
@@ -177,7 +179,7 @@ void radiussend(uint16_t r, uint8_t state)
 		return;
 	}
 
-	if (state != RADIUSAUTH && !config->radius_accounting)
+	if (state != RADIUSAUTH && state != RADIUSJUSTAUTH && !config->radius_accounting)
 	{
 		// Radius accounting is turned off
 		radiusclear(r, s);
@@ -197,7 +199,7 @@ void radiussend(uint16_t r, uint8_t state)
 	{
 		if (s)
 		{
-			if (state == RADIUSAUTH)
+			if (state == RADIUSAUTH || state == RADIUSJUSTAUTH)
 				sessionshutdown(s, "RADIUS timeout.", CDN_ADMIN_DISC, TERM_REAUTHENTICATION_FAILURE);
 			else
 			{
@@ -219,6 +221,7 @@ void radiussend(uint16_t r, uint8_t state)
 	switch (state)
 	{
 		case RADIUSAUTH:
+		case RADIUSJUSTAUTH:
 			b[0] = AccessRequest;               // access request
 			break;
 		case RADIUSSTART:
@@ -231,6 +234,7 @@ void radiussend(uint16_t r, uint8_t state)
 	}
 	b[1] = r >> RADIUS_SHIFT;       // identifier
 	memcpy(b + 4, radius[r].auth, 16);
+
 	p = b + 20;
 	if (s)
 	{
@@ -239,7 +243,7 @@ void radiussend(uint16_t r, uint8_t state)
 		strcpy((char *) p + 2, session[s].user);
 		p += p[1];
 	}
-	if (state == RADIUSAUTH)
+	if (state == RADIUSAUTH || state == RADIUSJUSTAUTH)
 	{
 		if (radius[r].chap)
 		{
@@ -364,6 +368,13 @@ void radiussend(uint16_t r, uint8_t state)
 				}
 			}
 
+			if (session[s].classlen) {
+				*p = 25;	// class
+				p[1] = session[s].classlen + 2;
+				memcpy(p + 2, session[s].class, session[s].classlen);
+				p += p[1];
+			}
+
 			{
 				struct param_radius_account acct = { &tunnel[session[s].tunnel], &session[s], &p };
 				run_plugins(PLUGIN_RADIUS_ACCOUNT, &acct);
@@ -380,12 +391,12 @@ void radiussend(uint16_t r, uint8_t state)
 
 	        *p = 6;		// Service-Type
 		p[1] = 6;
-		*(uint32_t *) (p + 2) = htonl(2); // Framed-User
+		*(uint32_t *) (p + 2) = htonl((state == RADIUSJUSTAUTH ? 8 : 2)); // Authenticate only or Framed-User respectevily
 		p += p[1];
 		   
 	        *p = 7;		// Framed-Protocol
-		p[1] = 6;
-		*(uint32_t *) (p + 2) = htonl(1); // PPP
+		p[1] = htonl((state == RADIUSJUSTAUTH ? 0 : 6));
+		*(uint32_t *) (p + 2) = htonl((state == RADIUSJUSTAUTH ? 0 : 1)); // PPP
 		p += p[1];
 
 		if (session[s].ip)
@@ -401,21 +412,11 @@ void radiussend(uint16_t r, uint8_t state)
 			int r;
 			for (r = 0; s && r < MAXROUTE && session[s].route[r].ip; r++)
 			{
-				int width = 32;
-				if (session[s].route[r].mask)
-				{
-				    int mask = session[s].route[r].mask;
-				    while (!(mask & 1))
-				    {
-					width--;
-					mask >>= 1;
-				    }
-				}
-
 				*p = 22;	// Framed-Route
 				p[1] = sprintf((char *) p + 2, "%s/%d %s 1",
 					fmtaddr(htonl(session[s].route[r].ip), 0),
-					width, fmtaddr(htonl(session[s].ip), 1)) + 2;
+					session[s].route[r].prefixlen,
+					fmtaddr(htonl(session[s].ip), 1)) + 2;
 
 				p += p[1];
 			}
@@ -462,7 +463,7 @@ void radiussend(uint16_t r, uint8_t state)
 
 	// All AVpairs added
 	*(uint16_t *) (b + 2) = htons(p - b);
-	if (state != RADIUSAUTH)
+	if (state != RADIUSAUTH && state != RADIUSJUSTAUTH)
 	{
 		// Build auth for accounting packet
 		calc_auth(b, p - b, zero, b + 4);
@@ -475,7 +476,7 @@ void radiussend(uint16_t r, uint8_t state)
 		// get radius port
 		uint16_t port = config->radiusport[(radius[r].try - 1) % config->numradiusservers];
 		// assume RADIUS accounting port is the authentication port +1
-		addr.sin_port = htons((state == RADIUSAUTH) ? port : port+1);
+		addr.sin_port = htons((state == RADIUSAUTH || state == RADIUSJUSTAUTH) ? port : port+1);
 	}
 
 	LOG_HEX(5, "RADIUS Send", b, (p - b));
@@ -534,6 +535,7 @@ void processrad(uint8_t *buf, int len, char socket_index)
 	uint8_t routes = 0;
 	int r_code;
 	int r_id;
+	int OpentunnelReq = 0;
 
 	CSTAT(processrad);
 
@@ -558,7 +560,7 @@ void processrad(uint8_t *buf, int len, char socket_index)
 		LOG(1, s, session[s].tunnel, "   Unexpected RADIUS response\n");
 		return;
 	}
-	if (radius[r].state != RADIUSAUTH && radius[r].state != RADIUSSTART
+	if (radius[r].state != RADIUSAUTH && radius[r].state != RADIUSJUSTAUTH && radius[r].state != RADIUSSTART
 	    && radius[r].state != RADIUSSTOP && radius[r].state != RADIUSINTERIM)
 	{
 		LOG(1, s, session[s].tunnel, "   Unexpected RADIUS response\n");
@@ -573,7 +575,7 @@ void processrad(uint8_t *buf, int len, char socket_index)
 			return; // Do nothing. On timeout, it will try the next radius server.
 		}
 
-		if ((radius[r].state == RADIUSAUTH && r_code != AccessAccept && r_code != AccessReject) ||
+		if (((radius[r].state == RADIUSAUTH ||radius[r].state == RADIUSJUSTAUTH) && r_code != AccessAccept && r_code != AccessReject) ||
 			((radius[r].state == RADIUSSTART || radius[r].state == RADIUSSTOP || radius[r].state == RADIUSINTERIM) && r_code != AccountingResponse))
 		{
 			LOG(1, s, session[s].tunnel, "   Unexpected RADIUS response %s\n", radius_code(r_code));
@@ -581,7 +583,7 @@ void processrad(uint8_t *buf, int len, char socket_index)
 				// care off finishing the radius session if that's really correct.
 		}
 
-		if (radius[r].state == RADIUSAUTH)
+		if (radius[r].state == RADIUSAUTH || radius[r].state == RADIUSJUSTAUTH)
 		{
 			// run post-auth plugin
 			struct param_post_auth packet = {
@@ -595,6 +597,7 @@ void processrad(uint8_t *buf, int len, char socket_index)
 			run_plugins(PLUGIN_POST_AUTH, &packet);
 			r_code = packet.auth_allowed ? AccessAccept : AccessReject;
 
+#ifndef LAC
 			// process auth response
 			if (radius[r].chap)
 			{
@@ -626,6 +629,7 @@ void processrad(uint8_t *buf, int len, char socket_index)
 				LOG(3, s, session[s].tunnel, "   PAP User %s authentication %s.\n", session[s].user,
 						(r_code == AccessAccept) ? "allowed" : "denied");
 			}
+#endif
 
 			if (r_code == AccessAccept)
 			{
@@ -633,8 +637,41 @@ void processrad(uint8_t *buf, int len, char socket_index)
 				// Extract IP, routes, etc
 				uint8_t *p = buf + 20;
 				uint8_t *e = buf + len;
+				uint8_t tag;
+				uint8_t strtemp[256];
+				lac_reset_rad_tag_tunnel_ctxt();
+
 				for (; p + 2 <= e && p[1] && p + p[1] <= e; p += p[1])
 				{
+					if (*p == 26 && p[1] >= 7)
+					{
+						// Vendor-Specific Attribute
+						uint32_t vendor = ntohl(*(int *)(p + 2));
+						uint8_t attrib = *(p + 6);
+						int attrib_length = *(p + 7) - 2;
+
+						LOG(4, s, session[s].tunnel, "   Radius reply contains Vendor-Specific.  Vendor=%u Attrib=%u Length=%d\n", vendor, attrib, attrib_length);
+						if (vendor == 9 && attrib == 1) // Cisco-AVPair
+						{
+							if (attrib_length < 0) continue;
+							LOG(3, s, session[s].tunnel, "      Cisco-AVPair value: %.*s\n",
+								attrib_length, p + 8);
+
+							handle_avpair(s, p + 8, attrib_length);
+							continue;
+						}
+						else if (vendor == 529 && attrib >= 135 && attrib <= 136) // Ascend
+						{
+							// handle old-format ascend DNS attributes below
+						    	p += 6;
+						}
+						else
+						{
+							LOG(3, s, session[s].tunnel, "      Unknown vendor-specific\n");
+							continue;
+						}
+					}
+
 					if (*p == 8)
 					{
 						// Framed-IP-Address
@@ -655,19 +692,6 @@ void processrad(uint8_t *buf, int len, char socket_index)
 						LOG(3, s, session[s].tunnel, "   Radius reply contains primary DNS address %s\n",
 							fmtaddr(htonl(session[s].dns1), 0));
 					}
-					else if (*p == 27)
-					{
-						// Session timeout
-					    	if (p[1] < 6) {
-							LOG(2, s, session[s].tunnel, "Error: Received Session timeout with length %d < 6\n", p[1]);
-							continue;
-						}
-
-						session[s].timeout = ntohl(*(uint32_t *) (p + 2));
-						LOG(3, s, session[s].tunnel, "   Radius reply contains Session timeout %d\n", session[s].timeout);
-						if (!session[s].timeout)
-							sessionshutdown(s, "Session timeout is zero", CDN_ADMIN_DISC, TERM_SESSION_TIMEOUT);
-					}
 					else if (*p == 136)
 					{
 						// DNS address
@@ -679,7 +703,7 @@ void processrad(uint8_t *buf, int len, char socket_index)
 					else if (*p == 22)
 					{
 						// Framed-Route
-						in_addr_t ip = 0, mask = 0;
+						in_addr_t ip = 0;
 						uint8_t u = 0;
 						uint8_t bits = 0;
 						uint8_t *n = p + 2;
@@ -701,14 +725,13 @@ void processrad(uint8_t *buf, int len, char socket_index)
 							n++;
 							while (n < e && isdigit(*n))
 								bits = bits * 10 + *n++ - '0';
-							mask = (( -1) << (32 - bits));
 						}
 						else if ((ip >> 24) < 128)
-							mask = 0xFF0000;
+							bits = 8;
 						else if ((ip >> 24) < 192)
-							mask = 0xFFFF0000;
+							bits = 16;
 						else
-							mask = 0xFFFFFF00;
+							bits = 24;
 
 						if (routes == MAXROUTE)
 						{
@@ -716,11 +739,11 @@ void processrad(uint8_t *buf, int len, char socket_index)
 						}
 						else if (ip)
 						{
-							LOG(3, s, session[s].tunnel, "   Radius reply contains route for %s/%s\n",
-								fmtaddr(htonl(ip), 0), fmtaddr(htonl(mask), 1));
+							LOG(3, s, session[s].tunnel, "   Radius reply contains route for %s/%d\n",
+								fmtaddr(htonl(ip), 0), bits);
 							
 							session[s].route[routes].ip = ip;
-							session[s].route[routes].mask = mask;
+							session[s].route[routes].prefixlen = bits;
 							routes++;
 						}
 					}
@@ -764,46 +787,18 @@ void processrad(uint8_t *buf, int len, char socket_index)
 					else if (*p == 27)
 					{
 					    	// Session-Timeout
-						uint32_t to = ntohl(*(uint32_t *)(p + 2));
-
-						LOG(3, s, session[s].tunnel, "   Radius reply contains Session-Timeout = %u\n", to);
-					        if (to > 0)
-					        {
-							session[s].session_timeout = to;
-					        }
+					    	if (p[1] < 6) continue;
+						session[s].session_timeout = ntohl(*(uint32_t *)(p + 2));
+						LOG(3, s, session[s].tunnel, "   Radius reply contains Session-Timeout = %u\n", session[s].session_timeout);
+						if(!session[s].session_timeout && config->kill_timedout_sessions)
+                                                        sessionshutdown(s, "Session timeout is zero", CDN_ADMIN_DISC, 0);
 					}
 					else if (*p == 28)
 					{
 					    	// Idle-Timeout
-						uint32_t to = ntohl(*(uint32_t *)(p + 2));
-
-						LOG(3, s, session[s].tunnel, "   Radius reply contains Idle-Timeout = %u\n", to);
-					        if (to > 0)
-					        {
-							session[s].idle_timeout = to;
-					        }
-					}
-					else if (*p == 26 && p[1] >= 7)
-					{
-						// Vendor-Specific Attribute
-						int vendor = ntohl(*(int *)(p + 2));
-						char attrib = *(p + 6);
-						int attrib_length = *(p + 7) - 2;
-
-						LOG(3, s, session[s].tunnel, "   Radius reply contains Vendor-Specific.  Vendor=%d Attrib=%d Length=%d\n", vendor, attrib, attrib_length);
-						if (vendor != 9 || attrib != 1)
-						{
-							LOG(3, s, session[s].tunnel, "      Unknown vendor-specific\n");
-							continue;
-						}
-
-						if (attrib_length > 0)
-						{
-							LOG(3, s, session[s].tunnel, "      Cisco-AVPair value: %.*s\n",
-								attrib_length, p + 8);
-
-							handle_avpair(s, p + 8, attrib_length);
-						}
+					    	if (p[1] < 6) continue;
+						session[s].idle_timeout = ntohl(*(uint32_t *)(p + 2));
+						LOG(3, s, session[s].tunnel, "   Radius reply contains Idle-Timeout = %u\n", session[s].idle_timeout);
 					}
 					else if (*p == 99)
 					{
@@ -831,6 +826,103 @@ void processrad(uint8_t *buf, int len, char socket_index)
 							session[s].ipv6prefixlen = prefixlen;
 						}
 					}
+					else if (*p == 25)
+					{
+						// Class
+						if (p[1] < 3) continue;
+						session[s].classlen = p[1] - 2;
+						if (session[s].classlen > MAXCLASS)
+							session[s].classlen = MAXCLASS;
+						memcpy(session[s].class, p + 2, session[s].classlen);
+					}
+					else if (*p == 64)
+					{
+						// Tunnel-Type
+						if (p[1] != 6) continue;
+						tag = p[2];
+						LOG(3, s, session[s].tunnel, "   Radius reply Tunnel-Type:%d %d\n",
+							tag, ntohl(*(uint32_t *)(p + 2)) & 0xFFFFFF);
+						// Fill context
+						lac_set_rad_tag_tunnel_type(tag, ntohl(*(uint32_t *)(p + 2)) & 0xFFFFFF);
+						/* Request open tunnel to remote LNS*/
+						OpentunnelReq = 1;
+					}
+					else if (*p == 65)
+					{
+						// Tunnel-Medium-Type
+						if (p[1] < 6) continue;
+						tag = p[2];
+						LOG(3, s, session[s].tunnel, "   Radius reply Tunnel-Medium-Type:%d %d\n",
+							tag, ntohl(*(uint32_t *)(p + 2)) & 0xFFFFFF);
+						// Fill context
+						lac_set_rad_tag_tunnel_medium_type(tag, ntohl(*(uint32_t *)(p + 2)) & 0xFFFFFF);
+					}
+					else if (*p == 67)
+					{
+						// Tunnel-Server-Endpoint
+						if (p[1] < 3) continue;
+						tag = p[2];
+						//If the Tag field is greater than 0x1F,
+						// it SHOULD be interpreted as the first byte of the following String field.
+						memset(strtemp, 0, 256);
+						if (tag > 0x1F)
+						{
+							tag = 0;
+							memcpy(strtemp, (p + 2), p[1]-2);
+						}
+						else
+							memcpy(strtemp, (p + 3), p[1]-3);
+
+						LOG(3, s, session[s].tunnel, "   Radius reply Tunnel-Server-Endpoint:%d %s\n", tag, strtemp);
+						// Fill context
+						lac_set_rad_tag_tunnel_serv_endpt(tag, (char *) strtemp);
+					}
+					else if (*p == 69)
+					{
+						// Tunnel-Password
+						size_t lentemp;
+
+						if (p[1] < 5) continue;
+						tag = p[2];
+
+						memset(strtemp, 0, 256);
+						lentemp = p[1]-3;
+						memcpy(strtemp, (p + 3), lentemp);
+						if (!rad_tunnel_pwdecode(strtemp, &lentemp, config->radiussecret, radius[r].auth))
+						{
+							LOG_HEX(3, "Error Decode Tunnel-Password, Dump Radius reponse:", p, p[1]);
+							continue;
+						}
+
+						LOG(3, s, session[s].tunnel, "   Radius reply Tunnel-Password:%d %s\n", tag, strtemp);
+						if (strlen((char *) strtemp) > 63)
+						{
+							LOG(1, s, session[s].tunnel, "tunnel password is too long (>63)\n");
+							continue;
+						}
+						// Fill context
+						lac_set_rad_tag_tunnel_password(tag, (char *) strtemp);
+					}
+					else if (*p == 82)
+					{
+						// Tunnel-Assignment-Id
+						if (p[1] < 3) continue;
+						tag = p[2];
+						//If the Tag field is greater than 0x1F,
+						// it SHOULD be interpreted as the first byte of the following String field.
+						memset(strtemp, 0, 256);
+						if (tag > 0x1F)
+						{
+							tag = 0;
+							memcpy(strtemp, (p + 2), p[1]-2);
+						}
+						else
+							memcpy(strtemp, (p + 3), p[1]-3);
+
+						LOG(3, s, session[s].tunnel, "   Radius reply Tunnel-Assignment-Id:%d %s\n", tag, strtemp);
+						// Fill context
+						lac_set_rad_tag_tunnel_assignment_id(tag, (char *) strtemp);
+					}
 				}
 			}
 			else if (r_code == AccessReject)
@@ -840,6 +932,63 @@ void processrad(uint8_t *buf, int len, char socket_index)
 				break;
 			}
 
+			if ((!config->disable_lac_func) && OpentunnelReq)
+			{
+				char assignment_id[256];
+				// Save radius tag context to conf
+				lac_save_rad_tag_tunnels(s);
+
+				memset(assignment_id, 0, 256);
+				if (!lac_rad_select_assignment_id(s, assignment_id))
+					break; // Error no assignment_id
+
+				LOG(3, s, session[s].tunnel, "Select Tunnel Remote LNS for assignment_id == %s\n", assignment_id);
+
+				if (lac_rad_forwardtoremotelns(s, assignment_id, session[s].user))
+				{
+					int ro;
+					// Sanity check, no local IP to session forwarded
+					session[s].ip = 0;
+					for (ro = 0; r < MAXROUTE && session[s].route[ro].ip; r++)
+					{
+						session[s].route[ro].ip = 0;
+					}
+					break;
+				}
+			}
+
+			// process auth response
+			if (radius[r].chap)
+			{
+				// CHAP
+				uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPCHAP, 0, 0, 0);
+				if (!p) return;	// Abort!
+
+				*p = (r_code == AccessAccept) ? 3 : 4;     // ack/nak
+				p[1] = radius[r].id;
+				*(uint16_t *) (p + 2) = ntohs(4); // no message
+				tunnelsend(b, (p - b) + 4, t); // send it
+
+				LOG(3, s, session[s].tunnel, "   CHAP User %s authentication %s.\n", session[s].user,
+						(r_code == AccessAccept) ? "allowed" : "denied");
+			}
+			else
+			{
+				// PAP
+				uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP, 0, 0, 0);
+				if (!p) return;		// Abort!
+
+				// ack/nak
+				*p = r_code;
+				p[1] = radius[r].id;
+				*(uint16_t *) (p + 2) = ntohs(5);
+				p[4] = 0; // no message
+				tunnelsend(b, (p - b) + 5, t); // send it
+
+				LOG(3, s, session[s].tunnel, "   PAP User %s authentication %s.\n", session[s].user,
+						(r_code == AccessAccept) ? "allowed" : "denied");
+			}
+
 			if (!session[s].dns1 && config->default_dns1)
 			{
 				session[s].dns1 = ntohl(config->default_dns1);
@@ -883,6 +1032,7 @@ void radiusretry(uint16_t r)
 			sendchap(s, t);
 			break;
 		case RADIUSAUTH:	// sending auth to RADIUS server
+		case RADIUSJUSTAUTH:	// sending auth to RADIUS server
 		case RADIUSSTART:	// sending start accounting to RADIUS server
 		case RADIUSSTOP:	// sending stop accounting to RADIUS server
 		case RADIUSINTERIM:	// sending interim accounting to RADIUS server
@@ -1181,3 +1331,94 @@ void processdae(uint8_t *buf, int len, struct sockaddr_in *addr, int alen, struc
 	if (sendtofrom(daefd, buf, len, MSG_DONTWAIT | MSG_NOSIGNAL, (struct sockaddr *) addr, alen, local) < 0)
 		LOG(0, 0, 0, "Error sending DAE response packet: %s\n", strerror(errno));
 }
+
+// Decrypte the encrypted Tunnel Password.
+// Defined in RFC-2868.
+// the pl2tpsecret buffer must set to 256 characters.
+// return 0 on decoding error else length of decoded l2tpsecret
+int rad_tunnel_pwdecode(uint8_t *pl2tpsecret, size_t *pl2tpsecretlen,
+						const char *radiussecret, const uint8_t * auth)
+{
+	MD5_CTX ctx, oldctx;
+	hasht hash;
+	int secretlen;
+	unsigned i, n, len, decodedlen;
+
+/* 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 6 7
+* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |     Salt      |     Salt      |   String ..........
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*/
+
+	len = *pl2tpsecretlen;
+
+	if (len < 2)
+	{
+		LOG(1, 0, 0, "tunnel password is too short, We need at least a salt\n");
+		return 0;
+	}
+
+	if (len <= 3)
+	{
+		pl2tpsecret[0] = 0;
+		*pl2tpsecretlen = 0;
+		LOG(1, 0, 0, "tunnel passwd is empty !!!\n");
+		return 0;
+	}
+
+	len -= 2;	/* discount the salt */
+
+	//Use the secret to setup the decryption
+	secretlen = strlen(radiussecret);
+
+	MD5_Init(&ctx);
+	MD5_Update(&ctx, (void *) radiussecret, secretlen);
+	oldctx = ctx;	/* save intermediate work */
+
+	// Set up the initial key:
+	//	b(1) = MD5(radiussecret + auth + salt)
+	MD5_Update(&ctx, (void *) auth, 16);
+	MD5_Update(&ctx, pl2tpsecret, 2);
+
+	decodedlen = 0;
+	for (n = 0; n < len; n += 16)
+	{
+		int base = 0;
+
+		if (n == 0)
+		{
+			MD5_Final(hash, &ctx);
+
+			ctx = oldctx;
+
+			 // the first octet, it's the 'data_len'
+			 // Check is correct
+			decodedlen = pl2tpsecret[2] ^ hash[0];
+			if (decodedlen >= len)
+			{
+				LOG(1, 0, 0, "tunnel password is too long !!!\n");
+				return 0;
+			}
+
+			MD5_Update(&ctx, pl2tpsecret + 2, 16);
+			base = 1;
+		} else
+		{
+			MD5_Final(hash, &ctx);
+
+			ctx = oldctx;
+			MD5_Update(&ctx, pl2tpsecret + n + 2, 16);
+		}
+
+		for (i = base; i < 16; i++)
+		{
+			pl2tpsecret[n + i - 1] = pl2tpsecret[n + i + 2] ^ hash[i];
+		}
+	}
+
+	if (decodedlen > 239) decodedlen = 239;
+
+	*pl2tpsecretlen = decodedlen;
+	pl2tpsecret[decodedlen] = 0;
+
+	return decodedlen;
+};