I'm sending the patch for NTLMv2 proxy authorization support. Please
note that I diffed against version 2.0.9 because it was the version that
I modified. Hope that it's not too confusing.
The features are:
-NTLMv2 support
-Allows user to specify authorization domain in username (both
DOMAIN\username and username@DOMAIN forms are supported). Applies both
to NTLM and NTLMv2.
-Uses keep-alive connection to proxy for NTLM and NTLMv2 to fix problems
with for ex. Squid proxy.
Tested with:
-ISA server
-Squid proxy
host OS both Windows XP and Linux
Miroslav Zajic
Nextsoft s.r.o.
diff -Naur openvpn-2.0.9/ntlm.c openvpn-NTLMv2-2.0.9/ntlm.c
--- openvpn-2.0.9/ntlm.c 2005-12-12 09:23:58.000000000 +0100
+++ openvpn-NTLMv2-2.0.9/ntlm.c 2008-01-13 18:18:45.761992000 +0100
@@ -3,6 +3,8 @@
*
* Copyright (C) 2004 William Preston
*
+ * *NTLMv2 support and domain name parsing by Miroslav Zajic, Nextsoft
s.r.o.*
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
@@ -41,146 +43,332 @@
#include "memdbg.h"
+
+
static void
create_des_keys(const unsigned char *hash, unsigned char *key)
{
- key[0] = hash[0];
- key[1] = ((hash[0]&1)<<7)|(hash[1]>>1);
- key[2] = ((hash[1]&3)<<6)|(hash[2]>>2);
- key[3] = ((hash[2]&7)<<5)|(hash[3]>>3);
- key[4] = ((hash[3]&15)<<4)|(hash[4]>>4);
- key[5] = ((hash[4]&31)<<3)|(hash[5]>>5);
- key[6] = ((hash[5]&63)<<2)|(hash[6]>>6);
- key[7] = ((hash[6]&127)<<1);
- des_set_odd_parity((des_cblock *)key);
+ key[0] = hash[0];
+ key[1] = ((hash[0]&1)<<7)|(hash[1]>>1);
+ key[2] = ((hash[1]&3)<<6)|(hash[2]>>2);
+ key[3] = ((hash[2]&7)<<5)|(hash[3]>>3);
+ key[4] = ((hash[3]&15)<<4)|(hash[4]>>4);
+ key[5] = ((hash[4]&31)<<3)|(hash[5]>>5);
+ key[6] = ((hash[5]&63)<<2)|(hash[6]>>6);
+ key[7] = ((hash[6]&127)<<1);
+ des_set_odd_parity((des_cblock *)key);
}
+
static void
gen_md4_hash (const char* data, int data_len, char *result)
{
- /* result is 16 byte md4 hash */
+ /* result is 16 byte md4 hash */
+
+ MD4_CTX c;
+ char md[16];
+
+ MD4_Init (&c);
+ MD4_Update (&c, data, data_len);
+ MD4_Final ((unsigned char *)md, &c);
+
+ memcpy (result, md, 16);
+}
+
+
+static void
+gen_hmac_md5 (const char* data, int data_len, const char* key, int
key_len,char *result)
+{
+ unsigned int len;
+
+ HMAC_CTX c;
+ HMAC_Init (&c, key, key_len, EVP_md5());
+ HMAC_Update (&c, data, data_len);
+ HMAC_Final (&c, result, &len);
+ HMAC_CTX_cleanup(&c);
+}
+
+
+static void
+gen_timestamp (unsigned char *timestamp)
+{
+ /* Copies 8 bytes long timestamp into "timestamp" buffer.
+ * Timestamp is Little-endian, 64-bit signed value representing the
number of tenths of a microsecond since January 1, 1601.
+ */
+
+ unsigned char bufA[8]; /* Buffer for 64-bit computing */
+ unsigned char bufB[8]; /* Second buffer */
+ int a, b, c, tmp, tmp2, carry;
+
+ /* set 64-bit buffer A with current time (seconds since 00:00:00
1.1.1970) */
+ *(unsigned int *)bufA = (unsigned int)time(NULL);
+ *(unsigned int *)&bufA[4] = (unsigned int)0;
+
+ /* 64-bit adition of 0x02B6109100 (seconds between 00:00:00
1.1.1601 and 00:00:00 1.1.1970) */
+ *(unsigned int *)bufB = (unsigned int)0xB6109100;
+ *(unsigned int *)&bufB[4] = (unsigned int)0x00000002;
+
+ carry=0;
+ for (a=0; a<8; a++){ /* lame adition */
+ tmp = (unsigned int)bufA[a] + (unsigned int)bufB[a] + carry;
+ bufA[a] = tmp & 0xFF;
+ carry = (tmp & 0xFF00) >> 8;
+ }
+
+ /* 64-bit multiply by 10000000 = 0x989680 (converting seconds to
tenths of microseconds) */
+ *(unsigned int *)bufB = (unsigned int)0x00989680;
+ *(unsigned int *)&bufB[4] = (unsigned int)0x00000000;
+ *(unsigned int *)timestamp = (unsigned int)0x00000000;
+ *(unsigned int *)×tamp[4] = (unsigned int)0x00000000;
+
+ for (a=0; a<8; a++){ /* lame multiply */
+ for (b=0; b<8; b++){
+ tmp = (unsigned int)bufA[a] * (unsigned int)bufB[b];
+ carry=0;
+ for (c=b; (c<8-a) && (c < b + 3); c++){
+ tmp2 = ((tmp & (0xFF << ((c-b) * 8))) >> ((c-b) * 8)) +
(unsigned int)timestamp[a+c] + carry;
+ timestamp[a+c] = tmp2 & 0xFF;
+ carry = (tmp2 & 0xFF00) >> 8;
+ }
+ }
+ }
+}
+
- MD4_CTX c;
- char md[16];
+static void
+gen_nonce (unsigned char *nonce)
+{
+ /* Generates 8 random bytes to be used as client nonce */
+ int i;
+
+ for(i=0;i<8;i++);
+ nonce[i] = (unsigned char)random();
+}
- MD4_Init (&c);
- MD4_Update (&c, data, data_len);
- MD4_Final ((unsigned char *)md, &c);
- memcpy (result, md, 16);
+unsigned char *my_strupr(unsigned char *str)
+{
+ /* converts string to uppercase in place */
+
+ unsigned char *tmp;
+ tmp = str;
+ do
+ {
+ if (*str >= 'a' && *str <= 'z')
+ *str -= 32;
+ }
+ while (*(++str));
+ return tmp;
}
+
static int
unicodize (char *dst, const char *src)
{
- /* not really unicode... */
- int i = 0;
- do
- {
- dst[i++] = *src;
- dst[i++] = 0;
- }
- while (*src++);
+ /* not really unicode... */
+ int i = 0;
+ do
+ {
+ dst[i++] = *src;
+ dst[i++] = 0;
+ }
+ while (*src++);
- return i;
+ return i;
}
+
+static void
+add_security_buffer(int sb_offset, void *data, int length, unsigned
char *msg_buf, int *msg_bufpos)
+{
+ /* Adds security buffer data to a message and sets security
buffer's offset and length */
+ msg_buf[sb_offset] = (unsigned char)length;
+ msg_buf[sb_offset + 2] = msg_buf[sb_offset];
+ msg_buf[sb_offset + 4] = *msg_bufpos;
+ memcpy(&msg_buf[*msg_bufpos], data, msg_buf[sb_offset]);
+ *msg_bufpos += length;
+}
+
+
+
+
+
const char *
ntlm_phase_1 (const struct http_proxy_info *p, struct gc_arena *gc)
{
- struct buffer out = alloc_buf_gc (96, gc);
- /* try a minimal NTLM handshake
- *
- * http://davenport.sourceforge.net/ntlm.html
- *
- * This message contains only the NTLMSSP signature,
- * the NTLM message type,
- * and the minimal set of flags (Negotiate NTLM and Negotiate OEM).
- *
- */
- buf_printf (&out, "%s", "TlRMTVNTUAABAAAAAgIAAA==");
- return (BSTR (&out));
+ struct buffer out = alloc_buf_gc (96, gc);
+ /* try a minimal NTLM handshake
+ *
+ * http://davenport.sourceforge.net/ntlm.html
+ *
+ * This message contains only the NTLMSSP signature,
+ * the NTLM message type,
+ * and the minimal set of flags (Negotiate NTLM and Negotiate OEM).
+ *
+ */
+ buf_printf (&out, "%s", "TlRMTVNTUAABAAAAAgIAAA==");
+ return (BSTR (&out));
}
+
const char *
ntlm_phase_3 (const struct http_proxy_info *p, const char *phase_2,
struct gc_arena *gc)
{
- char pwbuf[sizeof (p->up.password) * 2]; /* for unicode password */
- char buf2[128]; /* decoded reply from proxy */
- char phase3[146];
-
- char md4_hash[21];
- char challenge[8], response[24];
- int i, ret_val, buflen;
- des_cblock key1, key2, key3;
- des_key_schedule sched1, sched2, sched3;
-
- /* try a minimal NTLM handshake
- *
- * http://davenport.sourceforge.net/ntlm.html
- *
- */
- ASSERT (strlen (p->up.username) > 0);
- ASSERT (strlen (p->up.password) > 0);
-
- /* fill 1st 16 bytes with md4 hash, disregard terminating null */
- gen_md4_hash (pwbuf, unicodize (pwbuf, p->up.password) - 2, md4_hash);
-
- /* pad to 21 bytes */
- memset (md4_hash + 16, 0, 5);
-
- ret_val = base64_decode( phase_2, (void *)buf2);
- /* we can be sure that phase_2 is less than 128
- * therefore buf2 needs to be (3/4 * 128) */
-
- /* extract the challenge from bytes 24-31 */
- for (i=0; i<8; i++)
- {
- challenge[i] = buf2[i+24];
- }
-
- create_des_keys ((unsigned char *)md4_hash, key1);
- des_set_key_unchecked ((des_cblock *)key1, sched1);
- des_ecb_encrypt ((des_cblock *)challenge, (des_cblock *)response,
sched1, DES_ENCRYPT);
-
- create_des_keys ((unsigned char *)&(md4_hash[7]), key2);
- des_set_key_unchecked ((des_cblock *)key2, sched2);
- des_ecb_encrypt ((des_cblock *)challenge, (des_cblock
*)&(response[8]), sched2, DES_ENCRYPT);
-
- create_des_keys ((unsigned char *)&(md4_hash[14]), key3);
- des_set_key_unchecked ((des_cblock *)key3, sched3);
- des_ecb_encrypt ((des_cblock *)challenge, (des_cblock
*)&(response[16]), sched3, DES_ENCRYPT);
-
- /* clear reply */
- memset (phase3, 0, sizeof (phase3));
-
- strcpy (phase3, "NTLMSSP\0");
- phase3[8] = 3; /* type 3 */
-
- buflen = 0x58 + strlen (p->up.username);
- if (buflen > (int) sizeof (phase3))
- buflen = sizeof (phase3);
-
- phase3[0x10] = buflen; /* lm not used */
- phase3[0x20] = buflen; /* default domain (i.e. proxy's domain) */
- phase3[0x30] = buflen; /* no workstation name supplied */
- phase3[0x38] = buflen; /* no session key */
-
- phase3[0x14] = 24; /* ntlm response is 24 bytes long */
- phase3[0x16] = phase3[0x14];
- phase3[0x18] = 0x40; /* ntlm offset */
- memcpy (&(phase3[0x40]), response, 24);
-
-
- phase3[0x24] = strlen (p->up.username); /* username in ascii */
- phase3[0x26] = phase3[0x24];
- phase3[0x28] = 0x58;
- strncpy (&(phase3[0x58]), p->up.username, sizeof (phase3) - 0x58);
-
- phase3[0x3c] = 0x02; /* negotiate oem */
- phase3[0x3d] = 0x02; /* negotiate ntlm */
+ /* NTLM handshake
+ *
+ * http://davenport.sourceforge.net/ntlm.html
+ *
+ */
+
+ char pwbuf[sizeof (p->up.password) * 2]; /* for unicode password */
+ char buf2[128]; /* decoded reply from proxy */
+ unsigned char phase3[464];
+
+ char md4_hash[21];
+ char challenge[8], ntlm_response[24];
+ int i, ret_val;
+ des_cblock key1, key2, key3;
+ des_key_schedule sched1, sched2, sched3;
+
+ char ntlmv2_response[144];
+ char userdomain_u[256]; /* for uppercase unicode username and domain */
+ char userdomain[128]; /* the same as previous but ascii */
+ char ntlmv2_hash[16];
+ char ntlmv2_hmacmd5[16];
+ char *ntlmv2_blob = ntlmv2_response + 16; /* inside
ntlmv2_response, length: 128 */
+ int ntlmv2_blob_size=0;
+ int phase3_bufpos = 0x40; /* offset to next security buffer data to
be added */
+ int len;
+
+ char domain[128];
+ char username[128];
+ char *separator;
+
+ bool ntlmv2_enabled = (p->auth_method == HTTP_AUTH_NTLM2);
+
+
+ ASSERT (strlen (p->up.username) > 0);
+ ASSERT (strlen (p->up.password) > 0);
+
+ /* username parsing */
+ separator = strchr(p->up.username, '\\');
+ if (separator == NULL) {
+ strncpy(username, p->up.username, sizeof(username)-1);
+ username[sizeof(username)-1]=0;
+ domain[0]=0;
+ } else {
+ strncpy(username, separator+1, sizeof(username)-1);
+ username[sizeof(username)-1]=0;
+ len = separator - p->up.username;
+ if (len > sizeof(domain) - 1) len = sizeof(domain) - 1;
+ strncpy(domain, p->up.username, len);
+ domain[len]=0;
+ }
+
+
+ /* fill 1st 16 bytes with md4 hash, disregard terminating null */
+ gen_md4_hash (pwbuf, unicodize (pwbuf, p->up.password) - 2, md4_hash);
+
+ /* pad to 21 bytes */
+ memset (md4_hash + 16, 0, 5);
+
+ ret_val = base64_decode( phase_2, (void *)buf2);
+ /* we can be sure that phase_2 is less than 128
+ * therefore buf2 needs to be (3/4 * 128) */
+
+ /* extract the challenge from bytes 24-31 */
+ for (i=0; i<8; i++)
+ {
+ challenge[i] = buf2[i+24];
+ }
+
+ if (ntlmv2_enabled){ /* Generate NTLMv2 response */
+
+ /* NTLMv2 hash */
+ my_strupr(strcpy(userdomain, username));
+ if (strlen(username) + strlen(domain) < sizeof(userdomain))
+ strcat(userdomain, domain);
+ unicodize (userdomain_u, userdomain);
+ gen_hmac_md5(userdomain_u, 2 * strlen(userdomain), md4_hash,
16, ntlmv2_hash);
+
+ /* NTLMv2 Blob */
+ memset(ntlmv2_blob, 0, 128); /* Clear blob
buffer */
+ ntlmv2_blob[0x00]=1; /* Signature */
+ ntlmv2_blob[0x01]=1; /* Signature */
+ ntlmv2_blob[0x04]=0; /* Reserved */
+ gen_timestamp(&ntlmv2_blob[0x08]); /* 64-bit Timestamp */
+ gen_nonce(&ntlmv2_blob[0x10]); /* 64-bit Client
Nonce */
+ ntlmv2_blob[0x18]=0; /* Unknown, zero
should work */
+
+ /* Add target information block to the blob */
+ unsigned short tib_len;
+ if (( *((long *)&buf2[0x14]) & 0x00800000) == 0x00800000){ /*
Check for Target Information block */
+ tib_len = *((unsigned short *)&buf2[0x28]); /* Get Target
Information block size */
+ if (tib_len > 96) tib_len = 96;
+ char *tib_ptr = buf2 + buf2[0x2c]; /* Get Target
Information block pointer */
+ memcpy(&ntlmv2_blob[0x1c], tib_ptr, tib_len); /* Copy
Target Information block into the blob */
+ } else {
+ tib_len = 0;
+ }
+
+ ntlmv2_blob[0x1c + tib_len] = 0; /* Unknown, zero
works */
+
+ /* Get blob length */
+ ntlmv2_blob_size = 0x20 + tib_len;
+
+ /* Add challenge from message 2 */
+ memcpy(&ntlmv2_response[8], challenge, 8);
+
+ /* hmac-md5 */
+ gen_hmac_md5(&ntlmv2_response[8], ntlmv2_blob_size + 8,
ntlmv2_hash, 16, ntlmv2_hmacmd5);
+
+ /* Add hmac-md5 result to the blob */
+ memcpy(ntlmv2_response, ntlmv2_hmacmd5, 16); /* Note: This
overwrites challenge previously written at ntlmv2_response[8..15] */
+
+ } else { /* Generate NTLM response */
+
+ create_des_keys ((unsigned char *)md4_hash, key1);
+ des_set_key_unchecked ((des_cblock *)key1, sched1);
+ des_ecb_encrypt ((des_cblock *)challenge, (des_cblock
*)ntlm_response, sched1, DES_ENCRYPT);
+
+ create_des_keys ((unsigned char *)&(md4_hash[7]), key2);
+ des_set_key_unchecked ((des_cblock *)key2, sched2);
+ des_ecb_encrypt ((des_cblock *)challenge, (des_cblock
*)&(ntlm_response[8]), sched2, DES_ENCRYPT);
+
+ create_des_keys ((unsigned char *)&(md4_hash[14]), key3);
+ des_set_key_unchecked ((des_cblock *)key3, sched3);
+ des_ecb_encrypt ((des_cblock *)challenge, (des_cblock
*)&(ntlm_response[16]), sched3, DES_ENCRYPT);
+ }
+
+
+ memset (phase3, 0, sizeof (phase3)); /* clear reply */
+
+ strcpy (phase3, "NTLMSSP\0"); /* signature */
+ phase3[8] = 3; /* type 3 */
+
+ if (ntlmv2_enabled){ /* NTLMv2 response */
+ add_security_buffer(0x14, ntlmv2_response, ntlmv2_blob_size +
16, phase3, &phase3_bufpos);
+ }else{ /* NTLM response */
+ add_security_buffer(0x14, ntlm_response, 24, phase3,
&phase3_bufpos);
+ }
+
+ /* username in ascii */
+ add_security_buffer(0x24, username, strlen (username), phase3,
&phase3_bufpos);
+
+ /* Set domain. If <domain> is empty, default domain will be used
(i.e. proxy's domain) */
+ add_security_buffer(0x1c, domain, strlen (domain), phase3,
&phase3_bufpos);
+
+
+ /* other security buffers will be empty */
+ phase3[0x10] = phase3_bufpos; /* lm not used */
+ phase3[0x30] = phase3_bufpos; /* no workstation name supplied */
+ phase3[0x38] = phase3_bufpos; /* no session key */
+
+ /* flags */
+ phase3[0x3c] = 0x02; /* negotiate oem */
+ phase3[0x3d] = 0x02; /* negotiate ntlm */
- return ((const char *)make_base64_string2 ((unsigned char *)phase3,
buflen, gc));
+ return ((const char *)make_base64_string2 ((unsigned char *)phase3,
phase3_bufpos, gc));
}
#else
diff -Naur openvpn-2.0.9/proxy.c openvpn-NTLMv2-2.0.9/proxy.c
--- openvpn-2.0.9/proxy.c 2005-12-12 09:30:26.000000000 +0100
+++ openvpn-NTLMv2-2.0.9/proxy.c 2007-10-29 17:30:52.264678400 +0100
@@ -241,13 +241,15 @@
p->auth_method = HTTP_AUTH_BASIC;
else if (!strcmp (o->auth_method_string, "ntlm"))
p->auth_method = HTTP_AUTH_NTLM;
+ else if (!strcmp (o->auth_method_string, "ntlm2"))
+ p->auth_method = HTTP_AUTH_NTLM2;
else
- msg (M_FATAL, "ERROR: unknown HTTP authentication method: '%s' --
only the 'none', 'basic', or 'ntlm' methods are currently supported",
+ msg (M_FATAL, "ERROR: unknown HTTP authentication method: '%s' --
only the 'none', 'basic', 'ntlm', or 'ntlm2' methods are currently
supported",
o->auth_method_string);
}
- /* only basic and NTLM authentication supported so far */
- if (p->auth_method == HTTP_AUTH_BASIC || p->auth_method ==
HTTP_AUTH_NTLM)
+ /* only basic and NTLM/NTLMv2 authentication supported so far */
+ if (p->auth_method == HTTP_AUTH_BASIC || p->auth_method ==
HTTP_AUTH_NTLM || p->auth_method == HTTP_AUTH_NTLM2)
{
get_user_pass (&static_proxy_user_pass,
o->auth_file,
@@ -258,7 +260,7 @@
}
#if !NTLM
- if (p->auth_method == HTTP_AUTH_NTLM)
+ if (p->auth_method == HTTP_AUTH_NTLM || p->auth_method ==
HTTP_AUTH_NTLM2)
msg (M_FATAL, "Sorry, this version of " PACKAGE_NAME " was built
without NTLM Proxy support.");
#endif
@@ -302,6 +304,7 @@
goto error;
}
+
/* auth specified? */
switch (p->auth_method)
{
@@ -320,6 +323,12 @@
#if NTLM
case HTTP_AUTH_NTLM:
+ case HTTP_AUTH_NTLM2:
+ /* keep-alive connection */
+ openvpn_snprintf (buf, sizeof(buf), "Proxy-Connection: Keep-Alive");
+ if (!send_line_crlf (sd, buf))
+ goto error;
+
openvpn_snprintf (buf, sizeof(buf), "Proxy-Authorization: NTLM %s",
ntlm_phase_1 (p, &gc));
msg (D_PROXY, "Attempting NTLM Proxy-Authorization phase 1");
@@ -357,7 +366,7 @@
msg (D_PROXY, "Proxy requires authentication");
/* check for NTLM */
- if (p->auth_method == HTTP_AUTH_NTLM)
+ if (p->auth_method == HTTP_AUTH_NTLM || p->auth_method ==
HTTP_AUTH_NTLM2)
{
#if NTLM
/* look for the phase 2 response */
@@ -402,6 +411,12 @@
if (!send_line_crlf (sd, buf))
goto error;
+ /* keep-alive connection */
+ openvpn_snprintf (buf, sizeof(buf), "Proxy-Connection:
Keep-Alive");
+ if (!send_line_crlf (sd, buf))
+ goto error;
+
+
/* send HOST etc, */
openvpn_sleep (1);
openvpn_snprintf (buf, sizeof(buf), "Host: %s", host);
diff -Naur openvpn-2.0.9/proxy.h openvpn-NTLMv2-2.0.9/proxy.h
--- openvpn-2.0.9/proxy.h 2005-11-01 03:06:12.000000000 +0100
+++ openvpn-NTLMv2-2.0.9/proxy.h 2007-10-29 14:07:31.941475200 +0100
@@ -35,6 +35,7 @@
#define HTTP_AUTH_BASIC 1
#define HTTP_AUTH_NTLM 2
#define HTTP_AUTH_N 3
+#define HTTP_AUTH_NTLM2 4
struct http_proxy_options {
const char *server;
