diff --git a/flake.nix b/flake.nix
index 6378faa..828f296 100644
--- a/flake.nix
+++ b/flake.nix
@@ -10,6 +10,9 @@
     pname = "softether-5";
     version = "5.02.5187";
   in {
-    packages.${system}.default = pkgs.callPackage ./package.nix { inherit pname version; };
+    packages.${system} = {
+      default = pkgs.callPackage ./package.nix { inherit pname version; };
+      sha0 = pkgs.callPackage ./sha0 {};
+    };
   };
 }
diff --git a/package.nix b/package.nix
index 5d4bec9..cc65897 100644
--- a/package.nix
+++ b/package.nix
@@ -3,6 +3,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  debug ? false,
   pname ? "softether",
   logDir ? "/var/log/${pname}",
   pidDir ? "/run/${pname}",
@@ -22,6 +23,8 @@ stdenv.mkDerivation (finalAttrs: {
     fetchSubmodules = true;
   };
 
+  patches = [ ./patches/ipb-profile-key.patch ./patches/tap-name-no-prefix.patch ./patches/prevent-dmesg-call.patch ./patches/simplify_l2tp_auth.patch ];
+
   nativeBuildInputs = with pkgs; [
     cmake
     pkg-config
@@ -39,7 +42,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   cmakeFlags = [
     "-DSE_PIDDIR=${pidDir}" "-DSE_LOGDIR=${logDir}" "-DSE_DBDIR=${dbDir}" "-DCMAKE_INSTALL_SYSTEMD_UNITDIR="
-    "-DCMAKE_BUILD_TYPE=Debug"
+    (lib.optionalString debug "-DCMAKE_BUILD_TYPE=Debug")
     "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
     "-DCMAKE_INSTALL_LIBDIR=lib"
     "-DCMAKE_INSTALL_INCLUDEDIR=include"
diff --git a/patches/ipb-profile-key.patch b/patches/ipb-profile-key.patch
new file mode 100644
index 0000000..f4e987e
--- /dev/null
+++ b/patches/ipb-profile-key.patch
@@ -0,0 +1,112 @@
+diff --git a/src/Cedar/Proto_OpenVPN.c b/src/Cedar/Proto_OpenVPN.c
+index 9143d46..9e2d9d8 100644
+--- a/src/Cedar/Proto_OpenVPN.c
++++ b/src/Cedar/Proto_OpenVPN.c
+@@ -823,7 +823,8 @@ void OvsProcessRecvControlPacket(OPENVPN_SERVER *s, OPENVPN_SESSION *se, OPENVPN
+ 					s->Dh = DhNewFromBits(s->Cedar->DhParamBits);
+ 				}
+ 
+-				c->SslPipe = NewSslPipeEx(true, s->Cedar->ServerX, s->Cedar->ServerK, s->Dh, true, &c->ClientCert);
++				// disable automatic cert auth, use profileKey based auth instead
++				c->SslPipe = NewSslPipeEx(true, s->Cedar->ServerX, s->Cedar->ServerK, s->Dh, false, NULL);
+ 				if (c->SslPipe == NULL)
+ 				{
+ 					return;
+@@ -1477,6 +1478,36 @@ void OvsWriteStringToBuf(BUF *b, char *str, UINT max_size)
+ 	Free(tmp);
+ }
+ 
++// Extract the value of profile-key as UV_TOKEN from the openvpn peer info
++char *ExtractProfileKeyAsUvTokenFromPeerInfo(char *peerInfo)
++{
++	if (peerInfo == NULL) return NULL;
++
++	TOKEN_LIST *tokens = ParseTokenWithoutNullStr(peerInfo, "\r\n");
++	if (tokens == NULL) return NULL;
++
++	char *result = NULL;
++
++	for (UINT i = 0; i < tokens->NumTokens; i++)
++	{
++		char *line = tokens->Token[i];
++		Trim(line);
++		char key[1536], value[1536]; // same length allocated to peerInfo
++
++		if (GetKeyAndValue(line, key, sizeof(key), value, sizeof(value), "="))
++		{
++			if (StrCmpi(key, "UV_TOKEN") == 0)
++			{
++				result = CopyStr(value);
++				break;
++			}
++		}
++	}
++
++	FreeToken(tokens);
++	return result;
++}
++
+ // Parse the KEY_METHOD2
+ UINT OvsParseKeyMethod2(OPENVPN_KEY_METHOD_2 *ret, UCHAR *data, UINT size, bool client_mode)
+ {
+@@ -1527,6 +1558,16 @@ UINT OvsParseKeyMethod2(OPENVPN_KEY_METHOD_2 *ret, UCHAR *data, UINT size, bool
+ 		}
+ 	}
+ 
++	if(IsEmptyStr(ret->Username))
++	{
++		// keep it the same as softether protocol, which also sends entire profilekey as username and a password with any unimportant value
++		char *ProfileKey = ExtractProfileKeyAsUvTokenFromPeerInfo(ret->PeerInfo);
++		StrCpy(ret->Username, sizeof(ret->Username), ProfileKey);
++		ret->Password[0] = '\0'; // empty string
++
++		Free(ProfileKey);
++	}
++
+ 	FreeBuf(b);
+ 
+ 	return read_size;
+diff --git a/src/Cedar/Proto_OpenVPN.h b/src/Cedar/Proto_OpenVPN.h
+index 0ca10f0..a0ad37b 100644
+--- a/src/Cedar/Proto_OpenVPN.h
++++ b/src/Cedar/Proto_OpenVPN.h
+@@ -255,6 +255,7 @@ void OvsSendControlPacketEx(OPENVPN_CHANNEL *c, UCHAR opcode, UCHAR *data, UINT
+ void OvsSendControlPacketWithAutoSplit(OPENVPN_CHANNEL *c, UCHAR opcode, UCHAR *data, UINT data_size);
+ void OvsFreeControlPacket(OPENVPN_CONTROL_PACKET *p);
+ void OvsDeleteFromSendingControlPacketList(OPENVPN_CHANNEL *c, UINT num_acks, UINT *acks);
++char *ExtractProfileKeyAsUvTokenFromPeerInfo(char *str);
+ UINT OvsParseKeyMethod2(OPENVPN_KEY_METHOD_2 *ret, UCHAR *data, UINT size, bool client_mode);
+ bool OvsReadStringFromBuf(BUF *b, char *str, UINT str_size);
+ void OvsSetupSessionParameters(OPENVPN_SERVER *s, OPENVPN_SESSION *se, OPENVPN_CHANNEL *c, OPENVPN_KEY_METHOD_2 *data);
+diff --git a/src/Cedar/Protocol.c b/src/Cedar/Protocol.c
+index a0da6c7..d0c9838 100644
+--- a/src/Cedar/Protocol.c
++++ b/src/Cedar/Protocol.c
+@@ -2861,7 +2861,13 @@ bool ServerAccept(CONNECTION *c)
+ 			}
+ 
+ 			// Create a Session
+-			StrLower(username);
++			if (admin_mode == false && StrLen(username) == 6)
++			{
++				//concat password to username so it's the combined profileKey
++				//this is for recognizing L2TP clients
++				StrCat(username, sizeof(username), plain_password);
++			}
++
+ 			s = NewServerSessionEx(c->Cedar, c, hub, username, policy, c->IsInProc,
+ 				(c->IsInProc && IsZero(assigned_ipc_mac_address, 6) == false) ? assigned_ipc_mac_address : NULL);
+ 
+diff --git a/src/Cedar/Session.c b/src/Cedar/Session.c
+index e0bb58a..09e77b3 100644
+--- a/src/Cedar/Session.c
++++ b/src/Cedar/Session.c
+@@ -2186,7 +2186,7 @@ SESSION *NewServerSessionEx(CEDAR *cedar, CONNECTION *c, HUB *h, char *username,
+ 	StrCpy(hub_name_upper, sizeof(hub_name_upper), h->Name);
+ 	StrUpper(hub_name_upper);
+ 	StrCpy(user_name_upper, sizeof(user_name_upper), username);
+-	StrUpper(user_name_upper);
++	// do not uppercase the profileKey
+ 
+ 	if ((StrCmpi(username, ADMINISTRATOR_USERNAME) != 0) && (StrCmpi(username, BRIDGE_USER_NAME) != 0) || (cedar->Server == NULL || cedar->Server->ServerType == SERVER_TYPE_STANDALONE))
+ 	{
diff --git a/patches/prevent-dmesg-call.patch b/patches/prevent-dmesg-call.patch
new file mode 100644
index 0000000..3572d29
--- /dev/null
+++ b/patches/prevent-dmesg-call.patch
@@ -0,0 +1,12 @@
+diff --git a/src/Mayaqua/Unix.c b/src/Mayaqua/Unix.c
+index 0c3778d..657dea4 100644
+--- a/src/Mayaqua/Unix.c
++++ b/src/Mayaqua/Unix.c
+@@ -345,6 +345,7 @@ bool UnixIsInVmMain()
+ 
+ bool UnixIsInVm()
+ {
++	return false;
+ 	static bool is_in_vm_flag = false;
+ 	static bool is_in_vm_ret = false;
+ 
diff --git a/patches/simplify_l2tp_auth.patch b/patches/simplify_l2tp_auth.patch
new file mode 100644
index 0000000..d871b75
--- /dev/null
+++ b/patches/simplify_l2tp_auth.patch
@@ -0,0 +1,60 @@
+diff --git a/src/Cedar/Proto_PPP.c b/src/Cedar/Proto_PPP.c
+index e9908e0..120a65b 100644
+--- a/src/Cedar/Proto_PPP.c
++++ b/src/Cedar/Proto_PPP.c
+@@ -320,12 +320,12 @@ void PPPThread(THREAD *thread, void *param)
+ 
+ 		if (p->PPPStatus == PPP_STATUS_CONNECTED && authReqSent == false)
+ 		{
+-			// EAP code
++			// PAP code
+ 			PPP_LCP *c = NewPPPLCP(PPP_LCP_CODE_REQ, 0);
+-			USHORT eap_code = Endian16(PPP_LCP_AUTH_EAP);
++			USHORT pap_code = Endian16(PPP_LCP_AUTH_PAP);
+ 
+-			Debug("Request EAP\n");
+-			Add(c->OptionList, NewPPPOption(PPP_LCP_OPTION_AUTH, &eap_code, sizeof(eap_code)));
++			Debug("Request PAP\n");
++			Add(c->OptionList, NewPPPOption(PPP_LCP_OPTION_AUTH, &pap_code, sizeof(pap_code)));
+ 			if (PPPSendAndRetransmitRequest(p, PPP_PROTOCOL_LCP, c) == false)
+ 			{
+ 				PPPSetStatus(p, PPP_STATUS_FAIL);
+@@ -1871,12 +1871,6 @@ bool PPPProcessPAPRequestPacket(PPP_SESSION *p, PPP_PACKET *pp)
+ 
+ 									p->AuthOk = true;
+ 								}
+-								else
+-								{
+-									PPPSetStatus(p, PPP_STATUS_FAIL);
+-									WHERE;
+-									return false;
+-								}
+ 							}
+ 						}
+ 					}
+diff --git a/src/Cedar/Proto_PPP.h b/src/Cedar/Proto_PPP.h
+index 1278fbc..20500cc 100644
+--- a/src/Cedar/Proto_PPP.h
++++ b/src/Cedar/Proto_PPP.h
+@@ -32,18 +32,18 @@
+ #define	PPP_CODE_IS_REQUEST(protocol, c)	((((protocol) == PPP_PROTOCOL_LCP || (protocol) == PPP_PROTOCOL_IPCP || (protocol) == PPP_PROTOCOL_IPV6CP) && PPP_LCP_CODE_IS_REQUEST(c)) || (((protocol) == PPP_PROTOCOL_PAP) && PPP_PAP_CODE_IS_REQUEST(c)) || (((protocol) == PPP_PROTOCOL_CHAP) && PPP_CHAP_CODE_IS_REQUEST(c)) || (((protocol) == PPP_PROTOCOL_EAP) && PPP_EAP_CODE_IS_REQUEST(c)))
+ #define	PPP_CODE_IS_WITH_OPTION_LIST(protocol, c) ((((protocol) == PPP_PROTOCOL_LCP || (protocol) == PPP_PROTOCOL_IPCP || (protocol) == PPP_PROTOCOL_IPV6CP) && PPP_LCP_CODE_IS_WITH_OPTION_LIST(c)) || false)
+ 
+-#define	PPP_IS_SUPPORTED_PROTOCOL(p)		((p) == PPP_PROTOCOL_LCP || (p) == PPP_PROTOCOL_PAP || (p) == PPP_PROTOCOL_CHAP || (p) == PPP_PROTOCOL_IPCP || (p) == PPP_PROTOCOL_IPV6CP || (p) == PPP_PROTOCOL_IP || (p) == PPP_PROTOCOL_IPV6 || (p) == PPP_PROTOCOL_EAP )
++#define	PPP_IS_SUPPORTED_PROTOCOL(p)		((p) == PPP_PROTOCOL_LCP || (p) == PPP_PROTOCOL_PAP || (p) == PPP_PROTOCOL_IPCP || (p) == PPP_PROTOCOL_IP)
+ 
+ #define PPP_STATUS_IS_UNAVAILABLE(c)		((c) == PPP_STATUS_FAIL || (c) == PPP_STATUS_AUTH_FAIL || (c) == PPP_STATUS_CLOSING || (c) == PPP_STATUS_CLOSING_WAIT || (c) == PPP_STATUS_CLOSED)
+ 
+ //// Constants
+ 
+ // Time-out value
+-#define	PPP_PACKET_RECV_TIMEOUT			(15 * 1000)	// Timeout until the next packet is received (3/4 of default policy)
++#define	PPP_PACKET_RECV_TIMEOUT			(90 * 1000)	// Timeout until the next packet is received (3/4 of default policy)
+ #define	PPP_PACKET_RESEND_INTERVAL		(3 * 1000)	// Retransmission interval of the last packet
+ #define	PPP_TERMINATE_TIMEOUT			2000		// Timeout value to complete disconnection after requesting to disconnect in the PPP
+ #define	PPP_ECHO_SEND_INTERVAL			4792		// Transmission interval of PPP Echo Request
+-#define	PPP_DATA_TIMEOUT				(20 * 1000)	// Communication time-out (from default policy)
++#define	PPP_DATA_TIMEOUT				(120 * 1000)	// Communication time-out (from default policy)
+ 
+ // MRU
+ #define	PPP_MRU_DEFAULT					1500		// Default value
diff --git a/patches/tap-name-no-prefix.patch b/patches/tap-name-no-prefix.patch
new file mode 100644
index 0000000..17fe0f0
--- /dev/null
+++ b/patches/tap-name-no-prefix.patch
@@ -0,0 +1,13 @@
+diff --git a/src/Cedar/VLanUnix.c b/src/Cedar/VLanUnix.c
+index 784bd74..127d15e 100644
+--- a/src/Cedar/VLanUnix.c
++++ b/src/Cedar/VLanUnix.c
+@@ -339,7 +339,7 @@ void GenerateTunName(char *name, char *prefix, char *tun_name, size_t tun_name_l
+ 	StrCpy(instance_name_lower, sizeof(instance_name_lower), name);
+ 	Trim(instance_name_lower);
+ 	StrLower(instance_name_lower);
+-	Format(tun_name, tun_name_len, "%s_%s", prefix, instance_name_lower);
++	Format(tun_name, tun_name_len, "%s", instance_name_lower);
+ 
+ 	tun_name[15] = 0;
+ }
diff --git a/sha0/default.nix b/sha0/default.nix
new file mode 100644
index 0000000..5570057
--- /dev/null
+++ b/sha0/default.nix
@@ -0,0 +1,20 @@
+{ pkgs, stdenv, ... }:
+stdenv.mkDerivation {
+  pname = "sha0";
+  version = "0.1.0";
+
+  src = ./.;
+
+  buildPhase = ''
+    cc -O2 -o sha0 sha0.c main.c
+  '';
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp sha0 $out/bin/
+  '';
+
+  meta = with pkgs.lib; {
+    description = "SHA-0 hashing CLI tool";
+  };
+}
\ No newline at end of file
diff --git a/sha0/main.c b/sha0/main.c
new file mode 100644
index 0000000..d4bc99f
--- /dev/null
+++ b/sha0/main.c
@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <string.h>
+#include "types.h"
+
+// Declare the function from sha0.c
+const UCHAR* MY_SHA0_hash(const void* data, int len, UCHAR* digest);
+
+#define SHA0_DIGEST_SIZE 20
+
+int main(int argc, char **argv) {
+    if (argc != 2) {
+        fprintf(stderr, "Usage: %s <string>\n", argv[0]);
+        return 1;
+    }
+
+    UCHAR digest[SHA0_DIGEST_SIZE];
+    MY_SHA0_hash((const UCHAR *)argv[1], strlen(argv[1]), digest);
+
+    for (int i = 0; i < SHA0_DIGEST_SIZE; i++) {
+        printf("%02x", digest[i]);
+    }
+    printf("\n");
+
+    return 0;
+}
\ No newline at end of file
diff --git a/sha0/sha0.c b/sha0/sha0.c
new file mode 100644
index 0000000..37a0ff7
--- /dev/null
+++ b/sha0/sha0.c
@@ -0,0 +1,148 @@
+// Copied from softether's src/Cedar/Encrypt.c
+
+// define custom types as defined in SoftEther's code
+#include "types.h"
+
+// rest is copied as is
+
+/////////////////////////
+// SHA0 implementation //
+/////////////////////////
+
+// Source codes from:
+//  https://android.googlesource.com/platform/system/core/+/81df1cc77722000f8d0025c1ab00ced123aa573c/libmincrypt/sha.c
+//  https://android.googlesource.com/platform/system/core/+/81df1cc77722000f8d0025c1ab00ced123aa573c/include/mincrypt/hash-internal.h
+//  https://android.googlesource.com/platform/system/core/+/81df1cc77722000f8d0025c1ab00ced123aa573c/include/mincrypt/sha.h
+
+/*
+ * Copyright 2013 The Android Open Source Project
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Google Inc. nor the names of its contributors may
+ *       be used to endorse or promote products derived from this software
+ *       without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <string.h>
+
+#define rol(bits, value) (((value) << (bits)) | ((value) >> (32 - (bits))))
+
+typedef struct MY_SHA0_CTX {
+//	const HASH_VTAB * f;
+	UINT64 count;
+	UCHAR buf[64];
+	UINT state[8];  // upto SHA2
+} MY_SHA0_CTX;
+
+#define MY_SHA0_DIGEST_SIZE 20
+
+static void MY_SHA0_Transform(MY_SHA0_CTX* ctx) {
+	UINT W[80];
+	UINT A, B, C, D, E;
+	UCHAR* p = ctx->buf;
+	int t;
+	for(t = 0; t < 16; ++t) {
+		UINT tmp =  *p++ << 24;
+		tmp |= *p++ << 16;
+		tmp |= *p++ << 8;
+		tmp |= *p++;
+		W[t] = tmp;
+	}
+	for(; t < 80; t++) {
+		//W[t] = rol(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
+		W[t] = (1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
+	}
+	A = ctx->state[0];
+	B = ctx->state[1];
+	C = ctx->state[2];
+	D = ctx->state[3];
+	E = ctx->state[4];
+	for(t = 0; t < 80; t++) {
+		UINT tmp = rol(5,A) + E + W[t];
+		if (t < 20)
+			tmp += (D^(B&(C^D))) + 0x5A827999;
+		else if ( t < 40)
+			tmp += (B^C^D) + 0x6ED9EBA1;
+		else if ( t < 60)
+			tmp += ((B&C)|(D&(B|C))) + 0x8F1BBCDC;
+		else
+			tmp += (B^C^D) + 0xCA62C1D6;
+		E = D;
+		D = C;
+		C = rol(30,B);
+		B = A;
+		A = tmp;
+	}
+	ctx->state[0] += A;
+	ctx->state[1] += B;
+	ctx->state[2] += C;
+	ctx->state[3] += D;
+	ctx->state[4] += E;
+}
+void MY_SHA0_init(MY_SHA0_CTX* ctx) {
+	//ctx->f = &SHA_VTAB;
+	ctx->state[0] = 0x67452301;
+	ctx->state[1] = 0xEFCDAB89;
+	ctx->state[2] = 0x98BADCFE;
+	ctx->state[3] = 0x10325476;
+	ctx->state[4] = 0xC3D2E1F0;
+	ctx->count = 0;
+}
+void MY_SHA0_update(MY_SHA0_CTX* ctx, const void* data, int len) {
+	int i = (int) (ctx->count & 63);
+	const UCHAR* p = (const UCHAR*)data;
+	ctx->count += len;
+	while (len--) {
+		ctx->buf[i++] = *p++;
+		if (i == 64) {
+			MY_SHA0_Transform(ctx);
+			i = 0;
+		}
+	}
+}
+const UCHAR* MY_SHA0_final(MY_SHA0_CTX* ctx) {
+	UCHAR *p = ctx->buf;
+	UINT64 cnt = ctx->count * 8;
+	int i;
+	MY_SHA0_update(ctx, (UCHAR*)"\x80", 1);
+	while ((ctx->count & 63) != 56) {
+		MY_SHA0_update(ctx, (UCHAR*)"\0", 1);
+	}
+	for (i = 0; i < 8; ++i) {
+		UCHAR tmp = (UCHAR) (cnt >> ((7 - i) * 8));
+		MY_SHA0_update(ctx, &tmp, 1);
+	}
+	for (i = 0; i < 5; i++) {
+		UINT tmp = ctx->state[i];
+		*p++ = tmp >> 24;
+		*p++ = tmp >> 16;
+		*p++ = tmp >> 8;
+		*p++ = tmp >> 0;
+	}
+	return ctx->buf;
+}
+/* Convenience function */
+const UCHAR* MY_SHA0_hash(const void* data, int len, UCHAR* digest) {
+	MY_SHA0_CTX ctx;
+	MY_SHA0_init(&ctx);
+	MY_SHA0_update(&ctx, data, len);
+	memcpy(digest, MY_SHA0_final(&ctx), MY_SHA0_DIGEST_SIZE);
+	return digest;
+}
\ No newline at end of file
diff --git a/sha0/types.h b/sha0/types.h
new file mode 100644
index 0000000..4c0523b
--- /dev/null
+++ b/sha0/types.h
@@ -0,0 +1,8 @@
+#ifndef TYPES_H
+#define TYPES_H
+
+typedef unsigned long long UINT64;
+typedef unsigned char UCHAR;
+typedef unsigned int UINT;
+
+#endif