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-rw-r--r--src/openvpn/ntlm.c352
1 files changed, 352 insertions, 0 deletions
diff --git a/src/openvpn/ntlm.c b/src/openvpn/ntlm.c
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+/*
+ * ntlm proxy support for OpenVPN
+ *
+ * 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
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (see the file COPYING included with this
+ * distribution); if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if NTLM
+
+#include "common.h"
+#include "buffer.h"
+#include "misc.h"
+#include "socket.h"
+#include "fdmisc.h"
+#include "proxy.h"
+#include "ntlm.h"
+#include "base64.h"
+#include "crypto.h"
+
+#include "memdbg.h"
+
+
+/* 64bit datatype macros */
+#ifdef _MSC_VER
+ /* MS compilers */
+# define UINTEGER64 __int64
+# define UINT64(c) c ## Ui64
+#else
+ /* Non MS compilers */
+# define UINTEGER64 unsigned long long
+# define UINT64(c) c ## LL
+#endif
+
+
+
+
+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);
+ key_des_fixup(key, 8, 1);
+}
+
+static void
+gen_md4_hash (const char* data, int data_len, char *result)
+{
+ /* result is 16 byte md4 hash */
+ const md_kt_t *md4_kt = md_kt_get("MD4");
+ char md[MD4_DIGEST_LENGTH];
+
+ md_full(md4_kt, data, data_len, md);
+ memcpy (result, md, MD4_DIGEST_LENGTH);
+}
+
+static void
+gen_hmac_md5 (const char* data, int data_len, const char* key, int key_len,char *result)
+{
+ const md_kt_t *md5_kt = md_kt_get("MD5");
+ hmac_ctx_t hmac_ctx;
+ CLEAR(hmac_ctx);
+
+ hmac_ctx_init(&hmac_ctx, key, key_len, md5_kt);
+ hmac_ctx_update(&hmac_ctx, (const unsigned char *)data, data_len);
+ hmac_ctx_final(&hmac_ctx, (unsigned char *)result);
+ hmac_ctx_cleanup(&hmac_ctx);
+}
+
+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.
+ */
+
+ UINTEGER64 timestamp_ull;
+
+ timestamp_ull = openvpn_time(NULL);
+ timestamp_ull = (timestamp_ull + UINT64(11644473600)) * UINT64(10000000);
+
+ /* store little endian value */
+ timestamp[0]= timestamp_ull & UINT64(0xFF);
+ timestamp[1]= (timestamp_ull >> 8) & UINT64(0xFF);
+ timestamp[2]= (timestamp_ull >> 16) & UINT64(0xFF);
+ timestamp[3]= (timestamp_ull >> 24) & UINT64(0xFF);
+ timestamp[4]= (timestamp_ull >> 32) & UINT64(0xFF);
+ timestamp[5]= (timestamp_ull >> 40) & UINT64(0xFF);
+ timestamp[6]= (timestamp_ull >> 48) & UINT64(0xFF);
+ timestamp[7]= (timestamp_ull >> 56) & UINT64(0xFF);
+}
+
+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)get_random();
+ }
+}
+
+unsigned char *my_strupr(unsigned char *str)
+{
+ /* converts string to uppercase in place */
+ unsigned char *tmp = str;;
+
+ do *str = toupper(*str); 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++);
+
+ 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] = (unsigned char)(*msg_bufpos & 0xff);
+ msg_buf[sb_offset + 5] = (unsigned char)((*msg_bufpos >> 8) & 0xff);
+ 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));
+}
+
+const char *
+ntlm_phase_3 (const struct http_proxy_info *p, const char *phase_2, struct gc_arena *gc)
+{
+ /* 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[MD4_DIGEST_LENGTH+5];
+ char challenge[8], ntlm_response[24];
+ int i, ret_val;
+
+ 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[MD5_DIGEST_LENGTH];
+ 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 */
+ size_t len;
+
+ char domain[128];
+ char username[128];
+ char *separator;
+
+ bool ntlmv2_enabled = (p->auth_method == HTTP_AUTH_NTLM2);
+
+ CLEAR (buf2);
+
+ 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 + MD4_DIGEST_LENGTH, 0, 5);
+
+ ret_val = openvpn_base64_decode( phase_2, (void *)buf2, -1);
+ if (ret_val < 0)
+ return NULL;
+
+ /* 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 */
+ int tib_len;
+
+ /* NTLMv2 hash */
+ my_strupr((unsigned char *)strcpy(userdomain, username));
+ if (strlen(username) + strlen(domain) < sizeof(userdomain))
+ strcat(userdomain, domain);
+ else
+ msg (M_INFO, "Warning: Username or domain too long");
+ unicodize (userdomain_u, userdomain);
+ gen_hmac_md5(userdomain_u, 2 * strlen(userdomain), md4_hash, MD5_DIGEST_LENGTH, 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((unsigned char *)&ntlmv2_blob[0x08]); /* 64-bit Timestamp */
+ gen_nonce((unsigned char *)&ntlmv2_blob[0x10]); /* 64-bit Client Nonce */
+ ntlmv2_blob[0x18]=0; /* Unknown, zero should work */
+
+ /* Add target information block to the blob */
+ if (( *((long *)&buf2[0x14]) & 0x00800000) == 0x00800000){ /* Check for Target Information block */
+ tib_len = 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, MD5_DIGEST_LENGTH, ntlmv2_hmacmd5);
+
+ /* Add hmac-md5 result to the blob */
+ memcpy(ntlmv2_response, ntlmv2_hmacmd5, MD5_DIGEST_LENGTH); /* Note: This overwrites challenge previously written at ntlmv2_response[8..15] */
+
+ } else { /* Generate NTLM response */
+ unsigned char key1[DES_KEY_LENGTH], key2[DES_KEY_LENGTH], key3[DES_KEY_LENGTH];
+
+ create_des_keys ((unsigned char *)md4_hash, key1);
+ cipher_des_encrypt_ecb (key1, challenge, ntlm_response);
+
+ create_des_keys ((unsigned char *)&(md4_hash[DES_KEY_LENGTH-1]), key2);
+ cipher_des_encrypt_ecb (key2, challenge, &ntlm_response[DES_KEY_LENGTH]);
+
+ create_des_keys ((unsigned char *)&(md4_hash[2*(DES_KEY_LENGTH-1)]), key3);
+ cipher_des_encrypt_ecb (key3, challenge, &ntlm_response[DES_KEY_LENGTH*2]);
+ }
+
+
+ memset (phase3, 0, sizeof (phase3)); /* clear reply */
+
+ strcpy ((char *)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, phase3_bufpos, gc));
+}
+
+#else
+static void dummy(void) {}
+#endif
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