src/auth/ntlm/fake/ntlm_fake_auth.cc

   1 /*
   2  * Copyright (C) 1996-2017 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 "helper/protocol_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
  54 /* A couple of harmless helper macros */
  55 #define SEND(X) {debug("sending '%s' to squid\n",X); printf(X "\n");}
  56 #ifdef __GNUC__
  57 #define SEND2(X,Y...) {debug("sending '" X "' to squid\n",Y); printf(X "\n",Y);}
  58 #define SEND3(X,Y...) {debug("sending '" X "' to squid\n",Y); printf(X "\n",Y);}
  59 #define SEND4(X,Y...) {debug("sending '" X "' to squid\n",Y); printf(X "\n",Y);}
  60 #else
  61 /* no gcc, no debugging. varargs macros are a gcc extension */
  62 #define SEND2(X,Y) {debug("sending '" X "' to squid\n",Y); printf(X "\n",Y);}
  63 #define SEND3(X,Y,Z) {debug("sending '" X "' to squid\n",Y,Z); printf(X "\n",Y,Z);}
  64 #define SEND4(X,Y,Z,W) {debug("sending '" X "' to squid\n",Y,Z,W); printf(X "\n",Y,Z,W);}
  65 #endif
  66
  67 const char *authenticate_ntlm_domain = "WORKGROUP";
  68 int strip_domain_enabled = 0;
  69 int NTLM_packet_debug_enabled = 0;
  70
  71 /*
  72  * options:
  73  * -d enable debugging.
  74  * -v enable verbose NTLM packet debugging.
  75  * -l if specified, changes behavior on failures to last-ditch.
  76  */
  77 char *my_program_name = NULL;
  78
  79 static void
  80 usage(void)
  81 {
  82     fprintf(stderr,
  83             "Usage: %s [-d] [-v] [-h]\n"
  84             " -d  enable debugging.\n"
  85             " -S  strip domain from username.\n"
  86             " -v  enable verbose NTLM packet debugging.\n"
  87             " -h  this message\n\n",
  88             my_program_name);
  89 }
  90
  91 static void
  92 process_options(int argc, char *argv[])
  93 {
  94     int opt, had_error = 0;
  95
  96     opterr = 0;
  97     while (-1 != (opt = getopt(argc, argv, "hdvS"))) {
  98         switch (opt) {
  99         case 'd':
 100             debug_enabled = 1;
 101             break;
 102         case 'v':
 103             debug_enabled = 1;
 104             NTLM_packet_debug_enabled = 1;
 105             break;
 106         case 'S':
 107             strip_domain_enabled = 1;
 108             break;
 109         case 'h':
 110             usage();
 111             exit(0);
 112         case '?':
 113             opt = optopt;
 114         /* fall thru to default */
 115         default:
 116             fprintf(stderr, "unknown option: -%c. Exiting\n", opt);
 117             usage();
 118             had_error = 1;
 119         }
 120     }
 121     if (had_error)
 122         exit(1);
 123 }
 124
 125 int
 126 main(int argc, char *argv[])
 127 {
 128     char buf[HELPER_INPUT_BUFFER];
 129     int buflen = 0;
 130     uint8_t decodedBuf[HELPER_INPUT_BUFFER];
 131     int decodedLen;
 132     char user[NTLM_MAX_FIELD_LENGTH], domain[NTLM_MAX_FIELD_LENGTH];
 133     char *p;
 134     char helper_command[3];
 135     int len;
 136
 137     setbuf(stdout, NULL);
 138     setbuf(stderr, NULL);
 139
 140     my_program_name = argv[0];
 141
 142     process_options(argc, argv);
 143
 144     debug("%s " VERSION " " SQUID_BUILD_INFO " starting up...\n", my_program_name);
 145
 146     while (fgets(buf, HELPER_INPUT_BUFFER, stdin) != NULL) {
 147         user[0] = '\0';     /*no user code */
 148         domain[0] = '\0';       /*no domain code */
 149
 150         if ((p = strchr(buf, '\n')) != NULL)
 151             *p = '\0';      /* strip \n */
 152         buflen = strlen(buf);   /* keep this so we only scan the buffer for \0 once per loop */
 153         ntlmhdr *packet;
 154         struct base64_decode_ctx ctx;
 155         base64_decode_init(&ctx);
 156         size_t dstLen = 0;
 157         if (buflen > 3 &&
 158                 base64_decode_update(&ctx, &dstLen, decodedBuf, buflen-3, reinterpret_cast<const uint8_t*>(buf+3)) &&
 159                 base64_decode_final(&ctx)) {
 160             decodedLen = dstLen;
 161             packet = (ntlmhdr*)decodedBuf;
 162         } else {
 163             packet = NULL;
 164             decodedLen = 0;
 165         }
 166
 167         if (buflen > 3 && NTLM_packet_debug_enabled) {
 168             strncpy(helper_command, buf, 2);
 169             helper_command[2] = '\0';
 170             debug("Got '%s' from Squid with data:\n", helper_command);
 171             hex_dump((unsigned char *)decodedBuf, decodedLen);
 172         } else
 173             debug("Got '%s' from Squid\n", buf);
 174
 175         if (strncmp(buf, "YR", 2) == 0) {
 176             char nonce[NTLM_NONCE_LEN];
 177             ntlm_challenge chal;
 178             ntlm_make_nonce(nonce);
 179             if (buflen > 3 && packet) {
 180                 ntlm_negotiate *nego = (ntlm_negotiate *)packet;
 181                 ntlm_make_challenge(&chal, authenticate_ntlm_domain, NULL, nonce, NTLM_NONCE_LEN, nego->flags);
 182             } else {
 183                 ntlm_make_challenge(&chal, authenticate_ntlm_domain, NULL, nonce, NTLM_NONCE_LEN, NTLM_NEGOTIATE_ASCII);
 184             }
 185             // TODO: find out what this context means, and why only the fake auth helper contains it.
 186             chal.context_high = htole32(0x003a<<16);
 187
 188             len = sizeof(chal) - sizeof(chal.payload) + le16toh(chal.target.maxlen);
 189
 190             struct base64_encode_ctx eCtx;
 191             base64_encode_init(&eCtx);
 192             uint8_t *data = (uint8_t*)xcalloc(base64_encode_len(len), 1);
 193             size_t blen = base64_encode_update(&eCtx, data, len, reinterpret_cast<uint8_t*>(&chal));
 194             blen += base64_encode_final(&eCtx, data+blen);
 195             if (NTLM_packet_debug_enabled) {
 196                 printf("TT %.*s\n", (int)blen, data);
 197                 debug("sending 'TT' to squid with data:\n");
 198                 hex_dump((unsigned char *)&chal, len);
 199             } else
 200                 SEND3("TT %.*s", (int)blen, data);
 201             safe_free(data);
 202
 203         } else if (strncmp(buf, "KK ", 3) == 0) {
 204             if (!packet) {
 205                 SEND("BH received KK with no data! user=");
 206             } else if (ntlm_validate_packet(packet, NTLM_AUTHENTICATE) == NTLM_ERR_NONE) {
 207                 if (ntlm_unpack_auth((ntlm_authenticate *)packet, user, domain, decodedLen) == NTLM_ERR_NONE) {
 208                     lc(user);
 209                     if (strip_domain_enabled) {
 210                         SEND2("AF %s", user);
 211                     } else {
 212                         SEND4("AF %s%s%s", domain, (*domain?"\\":""), user);
 213                     }
 214                 } else {
 215                     lc(user);
 216                     SEND4("NA invalid credentials, user=%s%s%s", domain, (*domain?"\\":""), user);
 217                 }
 218             } else {
 219                 SEND("BH wrong packet type! user=");
 220             }
 221         }
 222     }
 223     exit(0);
 224 }
 225