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Diffstat (limited to 'openvpn/src/openvpn/ntlm.c')
-rw-r--r-- | openvpn/src/openvpn/ntlm.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/openvpn/src/openvpn/ntlm.c b/openvpn/src/openvpn/ntlm.c new file mode 100644 index 0000000..3390bdd --- /dev/null +++ b/openvpn/src/openvpn/ntlm.c @@ -0,0 +1,352 @@ +/* + * 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 |