helpers/ntlm_auth/fake/ntlm_fake_auth.cc

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /*
  10  * AUTHOR: Andrew Doran <ad@interlude.eu.org>
  11  * AUTHOR: Robert Collins <rbtcollins@hotmail.com>
  12  * AUTHOR: Guido Serassio <guido.serassio@acmeconsulting.it>
  13  */
  14
  15 /*
  16  * Example ntlm authentication program for Squid, based on the
  17  * original proxy_auth code from client_side.c, written by
  18  * Jon Thackray <jrmt@uk.gdscorp.com>. Initial ntlm code by
  19  * Andrew Doran <ad@interlude.eu.org>.
  20  *
  21  * This code gets the username and returns it. No validation is done.
  22  * and by the way: it is a complete patch-up. Use the "real thing" NTLMSSP
  23  * if you can.
  24  *
  25  * Revised by Guido Serassio: <guido.serassio@acmeconsulting.it>
  26  *
  27  * - Added negotiation of UNICODE char support
  28  * - More detailed debugging info
  29  *
  30  */
  31
  32 /* undefine this to have strict protocol adherence. You don't really need
  33  * that though */
  34 #define IGNORANCE_IS_BLISS
  35
  36 #include "squid.h"
  37 #include "base64.h"
  38 #include "helpers/defines.h"
  39 #include "ntlmauth/ntlmauth.h"
  40 #include "ntlmauth/support_bits.cci"
  41
  42 #include <cctype>
  43 #include <cstring>
  44 #if HAVE_CRYPT_H
  45 #include <crypt.h>
  46 #endif
  47 #if HAVE_PWD_H
  48 #include <pwd.h>
  49 #endif
  50 #if HAVE_GETOPT_H
  51 #include <getopt.h>
  52 #endif
  53 #if HAVE_STDINT_H
  54 #include <stdint.h>
  55 #endif
  56 #if HAVE_INTTYPES_H
  57 #include <inttypes.h>
  58 #endif
  59
  60 /* A couple of harmless helper macros */
  61 #define SEND(X) {debug("sending '%s' to squid\n",X); printf(X "\n");}
  62 #ifdef __GNUC__
  63 #define SEND2(X,Y...) {debug("sending '" X "' to squid\n",Y); printf(X "\n",Y);}
  64 #define SEND3(X,Y...) {debug("sending '" X "' to squid\n",Y); printf(X "\n",Y);}
  65 #define SEND4(X,Y...) {debug("sending '" X "' to squid\n",Y); printf(X "\n",Y);}
  66 #else
  67 /* no gcc, no debugging. varargs macros are a gcc extension */
  68 #define SEND2(X,Y) {debug("sending '" X "' to squid\n",Y); printf(X "\n",Y);}
  69 #define SEND3(X,Y,Z) {debug("sending '" X "' to squid\n",Y,Z); printf(X "\n",Y,Z);}
  70 #define SEND4(X,Y,Z,W) {debug("sending '" X "' to squid\n",Y,Z,W); printf(X "\n",Y,Z,W);}
  71 #endif
  72
  73 const char *authenticate_ntlm_domain = "WORKGROUP";
  74 int strip_domain_enabled = 0;
  75 int NTLM_packet_debug_enabled = 0;
  76
  77 /*
  78  * options:
  79  * -d enable debugging.
  80  * -v enable verbose NTLM packet debugging.
  81  * -l if specified, changes behavior on failures to last-ditch.
  82  */
  83 char *my_program_name = NULL;
  84
  85 static void
  86 usage(void)
  87 {
  88     fprintf(stderr,
  89             "Usage: %s [-d] [-v] [-h]\n"
  90             " -d  enable debugging.\n"
  91             " -S  strip domain from username.\n"
  92             " -v  enable verbose NTLM packet debugging.\n"
  93             " -h  this message\n\n",
  94             my_program_name);
  95 }
  96
  97 static void
  98 process_options(int argc, char *argv[])
  99 {
 100     int opt, had_error = 0;
 101
 102     opterr = 0;
 103     while (-1 != (opt = getopt(argc, argv, "hdvS"))) {
 104         switch (opt) {
 105         case 'd':
 106             debug_enabled = 1;
 107             break;
 108         case 'v':
 109             debug_enabled = 1;
 110             NTLM_packet_debug_enabled = 1;
 111             break;
 112         case 'S':
 113             strip_domain_enabled = 1;
 114             break;
 115         case 'h':
 116             usage();
 117             exit(0);
 118         case '?':
 119             opt = optopt;
 120         /* fall thru to default */
 121         default:
 122             fprintf(stderr, "unknown option: -%c. Exiting\n", opt);
 123             usage();
 124             had_error = 1;
 125         }
 126     }
 127     if (had_error)
 128         exit(1);
 129 }
 130
 131 int
 132 main(int argc, char *argv[])
 133 {
 134     char buf[HELPER_INPUT_BUFFER];
 135     int buflen = 0;
 136     uint8_t decodedBuf[HELPER_INPUT_BUFFER];
 137     int decodedLen;
 138     char user[NTLM_MAX_FIELD_LENGTH], domain[NTLM_MAX_FIELD_LENGTH];
 139     char *p;
 140     char helper_command[3];
 141     int len;
 142
 143     setbuf(stdout, NULL);
 144     setbuf(stderr, NULL);
 145
 146     my_program_name = argv[0];
 147
 148     process_options(argc, argv);
 149
 150     debug("%s build " __DATE__ ", " __TIME__ " starting up...\n", my_program_name);
 151
 152     while (fgets(buf, HELPER_INPUT_BUFFER, stdin) != NULL) {
 153         user[0] = '\0';     /*no user code */
 154         domain[0] = '\0';       /*no domain code */
 155
 156         if ((p = strchr(buf, '\n')) != NULL)
 157             *p = '\0';      /* strip \n */
 158         buflen = strlen(buf);   /* keep this so we only scan the buffer for \0 once per loop */
 159         ntlmhdr *packet;
 160         struct base64_decode_ctx ctx;
 161         base64_decode_init(&ctx);
 162         size_t dstLen = 0;
 163         if (buflen > 3 &&
 164                 base64_decode_update(&ctx, &dstLen, decodedBuf, buflen-3, reinterpret_cast<const uint8_t*>(buf+3)) &&
 165                 base64_decode_final(&ctx)) {
 166             decodedLen = dstLen;
 167             packet = (ntlmhdr*)decodedBuf;
 168         } else {
 169             packet = NULL;
 170             decodedLen = 0;
 171         }
 172
 173         if (buflen > 3 && NTLM_packet_debug_enabled) {
 174             strncpy(helper_command, buf, 2);
 175             helper_command[2] = '\0';
 176             debug("Got '%s' from Squid with data:\n", helper_command);
 177             hex_dump((unsigned char *)decodedBuf, decodedLen);
 178         } else
 179             debug("Got '%s' from Squid\n", buf);
 180
 181         if (strncmp(buf, "YR", 2) == 0) {
 182             char nonce[NTLM_NONCE_LEN];
 183             ntlm_challenge chal;
 184             ntlm_make_nonce(nonce);
 185             if (buflen > 3 && packet) {
 186                 ntlm_negotiate *nego = (ntlm_negotiate *)packet;
 187                 ntlm_make_challenge(&chal, authenticate_ntlm_domain, NULL, nonce, NTLM_NONCE_LEN, nego->flags);
 188             } else {
 189                 ntlm_make_challenge(&chal, authenticate_ntlm_domain, NULL, nonce, NTLM_NONCE_LEN, NTLM_NEGOTIATE_ASCII);
 190             }
 191             // TODO: find out what this context means, and why only the fake auth helper contains it.
 192             chal.context_high = htole32(0x003a<<16);
 193
 194             len = sizeof(chal) - sizeof(chal.payload) + le16toh(chal.target.maxlen);
 195
 196             struct base64_encode_ctx eCtx;
 197             base64_encode_init(&eCtx);
 198             uint8_t *data = (uint8_t*)xcalloc(base64_encode_len(len), 1);
 199             size_t blen = base64_encode_update(&eCtx, data, len, reinterpret_cast<uint8_t*>(&chal));
 200             blen += base64_encode_final(&eCtx, data+blen);
 201             if (NTLM_packet_debug_enabled) {
 202                 printf("TT %.*s\n", (int)blen, data);
 203                 debug("sending 'TT' to squid with data:\n");
 204                 hex_dump((unsigned char *)&chal, len);
 205             } else
 206                 SEND3("TT %.*s", (int)blen, data);
 207             safe_free(data);
 208
 209         } else if (strncmp(buf, "KK ", 3) == 0) {
 210             if (!packet) {
 211                 SEND("BH received KK with no data! user=");
 212             } else if (ntlm_validate_packet(packet, NTLM_AUTHENTICATE) == NTLM_ERR_NONE) {
 213                 if (ntlm_unpack_auth((ntlm_authenticate *)packet, user, domain, decodedLen) == NTLM_ERR_NONE) {
 214                     lc(user);
 215                     if (strip_domain_enabled) {
 216                         SEND2("AF %s", user);
 217                     } else {
 218                         SEND4("AF %s%s%s", domain, (*domain?"\\":""), user);
 219                     }
 220                 } else {
 221                     lc(user);
 222                     SEND4("NA invalid credentials, user=%s%s%s", domain, (*domain?"\\":""), user);
 223                 }
 224             } else {
 225                 SEND("BH wrong packet type! user=");
 226             }
 227         }
 228     }
 229     exit(0);
 230 }
 231