1 | /*** WARNING - THIS HAS NEVER BEEN FINISHED ***/
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2 | /*****************************************************************************
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3 | * chap.c - Network Challenge Handshake Authentication Protocol program file.
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4 | *
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5 | * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
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6 | * portions Copyright (c) 1997 by Global Election Systems Inc.
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7 | *
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8 | * The authors hereby grant permission to use, copy, modify, distribute,
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9 | * and license this software and its documentation for any purpose, provided
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10 | * that existing copyright notices are retained in all copies and that this
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11 | * notice and the following disclaimer are included verbatim in any
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12 | * distributions. No written agreement, license, or royalty fee is required
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13 | * for any of the authorized uses.
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14 | *
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15 | * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
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16 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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17 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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18 | * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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19 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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20 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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21 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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22 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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23 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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24 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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25 | *
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26 | ******************************************************************************
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27 | * REVISION HISTORY
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28 | *
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29 | * 03-01-01 Marc Boucher <marc@mbsi.ca>
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30 | * Ported to lwIP.
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31 | * 97-12-04 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
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32 | * Original based on BSD chap.c.
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33 | *****************************************************************************/
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34 | /*
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35 | * chap.c - Challenge Handshake Authentication Protocol.
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36 | *
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37 | * Copyright (c) 1993 The Australian National University.
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38 | * All rights reserved.
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39 | *
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40 | * Redistribution and use in source and binary forms are permitted
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41 | * provided that the above copyright notice and this paragraph are
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42 | * duplicated in all such forms and that any documentation,
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43 | * advertising materials, and other materials related to such
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44 | * distribution and use acknowledge that the software was developed
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45 | * by the Australian National University. The name of the University
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46 | * may not be used to endorse or promote products derived from this
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47 | * software without specific prior written permission.
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48 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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49 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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50 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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51 | *
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52 | * Copyright (c) 1991 Gregory M. Christy.
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53 | * All rights reserved.
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54 | *
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55 | * Redistribution and use in source and binary forms are permitted
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56 | * provided that the above copyright notice and this paragraph are
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57 | * duplicated in all such forms and that any documentation,
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58 | * advertising materials, and other materials related to such
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59 | * distribution and use acknowledge that the software was developed
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60 | * by Gregory M. Christy. The name of the author may not be used to
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61 | * endorse or promote products derived from this software without
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62 | * specific prior written permission.
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63 | *
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64 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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65 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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66 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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67 | */
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68 |
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69 | #include "lwip/opt.h"
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70 |
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71 | #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
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72 |
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73 | #if CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
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74 |
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75 | #include "ppp_impl.h"
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76 | #include "pppdebug.h"
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77 |
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78 | #include "magic.h"
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79 | #include "randm.h"
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80 | #include "auth.h"
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81 | #include "md5.h"
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82 | #include "chap.h"
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83 | #include "chpms.h"
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84 |
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85 | #include <string.h>
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86 |
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87 | #if 0 /* UNUSED */
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88 | /*
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89 | * Command-line options.
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90 | */
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91 | static option_t chap_option_list[] = {
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92 | { "chap-restart", o_int, &chap[0].timeouttime,
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93 | "Set timeout for CHAP" },
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94 | { "chap-max-challenge", o_int, &chap[0].max_transmits,
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95 | "Set max #xmits for challenge" },
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96 | { "chap-interval", o_int, &chap[0].chal_interval,
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97 | "Set interval for rechallenge" },
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98 | #ifdef MSLANMAN
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99 | { "ms-lanman", o_bool, &ms_lanman,
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100 | "Use LanMan passwd when using MS-CHAP", 1 },
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101 | #endif
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102 | { NULL }
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103 | };
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104 | #endif /* UNUSED */
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105 |
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106 | /*
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107 | * Protocol entry points.
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108 | */
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109 | static void ChapInit (int);
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110 | static void ChapLowerUp (int);
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111 | static void ChapLowerDown (int);
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112 | static void ChapInput (int, u_char *, int);
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113 | static void ChapProtocolReject (int);
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114 | #if PPP_ADDITIONAL_CALLBACKS
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115 | static int ChapPrintPkt (u_char *, int, void (*) (void *, char *, ...), void *);
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116 | #endif
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117 |
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118 | struct protent chap_protent = {
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119 | PPP_CHAP,
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120 | ChapInit,
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121 | ChapInput,
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122 | ChapProtocolReject,
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123 | ChapLowerUp,
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124 | ChapLowerDown,
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125 | NULL,
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126 | NULL,
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127 | #if PPP_ADDITIONAL_CALLBACKS
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128 | ChapPrintPkt,
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129 | NULL,
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130 | #endif /* PPP_ADDITIONAL_CALLBACKS */
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131 | 1,
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132 | "CHAP",
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133 | #if PPP_ADDITIONAL_CALLBACKS
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134 | NULL,
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135 | NULL,
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136 | NULL
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137 | #endif /* PPP_ADDITIONAL_CALLBACKS */
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138 | };
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139 |
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140 | chap_state chap[NUM_PPP]; /* CHAP state; one for each unit */
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141 |
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142 | static void ChapChallengeTimeout (void *);
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143 | static void ChapResponseTimeout (void *);
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144 | static void ChapReceiveChallenge (chap_state *, u_char *, u_char, int);
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145 | static void ChapRechallenge (void *);
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146 | static void ChapReceiveResponse (chap_state *, u_char *, int, int);
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147 | static void ChapReceiveSuccess(chap_state *cstate, u_char *inp, u_char id, int len);
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148 | static void ChapReceiveFailure(chap_state *cstate, u_char *inp, u_char id, int len);
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149 | static void ChapSendStatus (chap_state *, int);
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150 | static void ChapSendChallenge (chap_state *);
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151 | static void ChapSendResponse (chap_state *);
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152 | static void ChapGenChallenge (chap_state *);
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153 |
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154 | /*
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155 | * ChapInit - Initialize a CHAP unit.
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156 | */
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157 | static void
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158 | ChapInit(int unit)
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159 | {
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160 | chap_state *cstate = &chap[unit];
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161 |
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162 | BZERO(cstate, sizeof(*cstate));
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163 | cstate->unit = unit;
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164 | cstate->clientstate = CHAPCS_INITIAL;
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165 | cstate->serverstate = CHAPSS_INITIAL;
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166 | cstate->timeouttime = CHAP_DEFTIMEOUT;
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167 | cstate->max_transmits = CHAP_DEFTRANSMITS;
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168 | /* random number generator is initialized in magic_init */
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169 | }
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170 |
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171 |
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172 | /*
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173 | * ChapAuthWithPeer - Authenticate us with our peer (start client).
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174 | *
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175 | */
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176 | void
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177 | ChapAuthWithPeer(int unit, char *our_name, u_char digest)
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178 | {
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179 | chap_state *cstate = &chap[unit];
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180 |
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181 | cstate->resp_name = our_name;
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182 | cstate->resp_type = digest;
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183 |
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184 | if (cstate->clientstate == CHAPCS_INITIAL ||
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185 | cstate->clientstate == CHAPCS_PENDING) {
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186 | /* lower layer isn't up - wait until later */
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187 | cstate->clientstate = CHAPCS_PENDING;
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188 | return;
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189 | }
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190 |
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191 | /*
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192 | * We get here as a result of LCP coming up.
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193 | * So even if CHAP was open before, we will
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194 | * have to re-authenticate ourselves.
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195 | */
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196 | cstate->clientstate = CHAPCS_LISTEN;
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197 | }
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198 |
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199 |
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200 | /*
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201 | * ChapAuthPeer - Authenticate our peer (start server).
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202 | */
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203 | void
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204 | ChapAuthPeer(int unit, char *our_name, u_char digest)
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205 | {
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206 | chap_state *cstate = &chap[unit];
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207 |
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208 | cstate->chal_name = our_name;
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209 | cstate->chal_type = digest;
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210 |
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211 | if (cstate->serverstate == CHAPSS_INITIAL ||
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212 | cstate->serverstate == CHAPSS_PENDING) {
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213 | /* lower layer isn't up - wait until later */
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214 | cstate->serverstate = CHAPSS_PENDING;
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215 | return;
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216 | }
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217 |
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218 | ChapGenChallenge(cstate);
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219 | ChapSendChallenge(cstate); /* crank it up dude! */
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220 | cstate->serverstate = CHAPSS_INITIAL_CHAL;
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221 | }
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222 |
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223 |
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224 | /*
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225 | * ChapChallengeTimeout - Timeout expired on sending challenge.
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226 | */
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227 | static void
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228 | ChapChallengeTimeout(void *arg)
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229 | {
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230 | chap_state *cstate = (chap_state *) arg;
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231 |
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232 | /* if we aren't sending challenges, don't worry. then again we */
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233 | /* probably shouldn't be here either */
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234 | if (cstate->serverstate != CHAPSS_INITIAL_CHAL &&
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235 | cstate->serverstate != CHAPSS_RECHALLENGE) {
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236 | return;
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237 | }
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238 |
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239 | if (cstate->chal_transmits >= cstate->max_transmits) {
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240 | /* give up on peer */
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241 | CHAPDEBUG(LOG_ERR, ("Peer failed to respond to CHAP challenge\n"));
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242 | cstate->serverstate = CHAPSS_BADAUTH;
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243 | auth_peer_fail(cstate->unit, PPP_CHAP);
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244 | return;
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245 | }
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246 |
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247 | ChapSendChallenge(cstate); /* Re-send challenge */
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248 | }
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249 |
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250 |
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251 | /*
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252 | * ChapResponseTimeout - Timeout expired on sending response.
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253 | */
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254 | static void
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255 | ChapResponseTimeout(void *arg)
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256 | {
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257 | chap_state *cstate = (chap_state *) arg;
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258 |
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259 | /* if we aren't sending a response, don't worry. */
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260 | if (cstate->clientstate != CHAPCS_RESPONSE) {
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261 | return;
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262 | }
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263 |
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264 | ChapSendResponse(cstate); /* re-send response */
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265 | }
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266 |
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267 |
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268 | /*
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269 | * ChapRechallenge - Time to challenge the peer again.
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270 | */
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271 | static void
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272 | ChapRechallenge(void *arg)
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273 | {
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274 | chap_state *cstate = (chap_state *) arg;
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275 |
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276 | /* if we aren't sending a response, don't worry. */
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277 | if (cstate->serverstate != CHAPSS_OPEN) {
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278 | return;
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279 | }
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280 |
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281 | ChapGenChallenge(cstate);
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282 | ChapSendChallenge(cstate);
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283 | cstate->serverstate = CHAPSS_RECHALLENGE;
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284 | }
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285 |
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286 |
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287 | /*
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288 | * ChapLowerUp - The lower layer is up.
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289 | *
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290 | * Start up if we have pending requests.
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291 | */
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292 | static void
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293 | ChapLowerUp(int unit)
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294 | {
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295 | chap_state *cstate = &chap[unit];
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296 |
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297 | if (cstate->clientstate == CHAPCS_INITIAL) {
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298 | cstate->clientstate = CHAPCS_CLOSED;
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299 | } else if (cstate->clientstate == CHAPCS_PENDING) {
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300 | cstate->clientstate = CHAPCS_LISTEN;
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301 | }
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302 |
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303 | if (cstate->serverstate == CHAPSS_INITIAL) {
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304 | cstate->serverstate = CHAPSS_CLOSED;
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305 | } else if (cstate->serverstate == CHAPSS_PENDING) {
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306 | ChapGenChallenge(cstate);
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307 | ChapSendChallenge(cstate);
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308 | cstate->serverstate = CHAPSS_INITIAL_CHAL;
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309 | }
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310 | }
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311 |
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312 |
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313 | /*
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314 | * ChapLowerDown - The lower layer is down.
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315 | *
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316 | * Cancel all timeouts.
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317 | */
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318 | static void
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319 | ChapLowerDown(int unit)
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320 | {
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321 | chap_state *cstate = &chap[unit];
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322 |
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323 | /* Timeout(s) pending? Cancel if so. */
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324 | if (cstate->serverstate == CHAPSS_INITIAL_CHAL ||
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325 | cstate->serverstate == CHAPSS_RECHALLENGE) {
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326 | UNTIMEOUT(ChapChallengeTimeout, cstate);
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327 | } else if (cstate->serverstate == CHAPSS_OPEN
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328 | && cstate->chal_interval != 0) {
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329 | UNTIMEOUT(ChapRechallenge, cstate);
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330 | }
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331 | if (cstate->clientstate == CHAPCS_RESPONSE) {
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332 | UNTIMEOUT(ChapResponseTimeout, cstate);
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333 | }
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334 | cstate->clientstate = CHAPCS_INITIAL;
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335 | cstate->serverstate = CHAPSS_INITIAL;
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336 | }
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337 |
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338 |
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339 | /*
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340 | * ChapProtocolReject - Peer doesn't grok CHAP.
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341 | */
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342 | static void
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343 | ChapProtocolReject(int unit)
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344 | {
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345 | chap_state *cstate = &chap[unit];
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346 |
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347 | if (cstate->serverstate != CHAPSS_INITIAL &&
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348 | cstate->serverstate != CHAPSS_CLOSED) {
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349 | auth_peer_fail(unit, PPP_CHAP);
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350 | }
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351 | if (cstate->clientstate != CHAPCS_INITIAL &&
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352 | cstate->clientstate != CHAPCS_CLOSED) {
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353 | auth_withpeer_fail(unit, PPP_CHAP); /* lwip: just sets the PPP error code on this unit to PPPERR_AUTHFAIL */
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354 | }
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355 | ChapLowerDown(unit); /* shutdown chap */
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356 | }
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357 |
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358 |
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359 | /*
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360 | * ChapInput - Input CHAP packet.
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361 | */
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362 | static void
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363 | ChapInput(int unit, u_char *inpacket, int packet_len)
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364 | {
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365 | chap_state *cstate = &chap[unit];
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366 | u_char *inp;
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367 | u_char code, id;
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368 | int len;
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369 |
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370 | /*
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371 | * Parse header (code, id and length).
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372 | * If packet too short, drop it.
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373 | */
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374 | inp = inpacket;
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375 | if (packet_len < CHAP_HEADERLEN) {
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376 | CHAPDEBUG(LOG_INFO, ("ChapInput: rcvd short header.\n"));
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377 | return;
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378 | }
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379 | GETCHAR(code, inp);
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380 | GETCHAR(id, inp);
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381 | GETSHORT(len, inp);
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382 | if (len < CHAP_HEADERLEN) {
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383 | CHAPDEBUG(LOG_INFO, ("ChapInput: rcvd illegal length.\n"));
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384 | return;
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385 | }
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386 | if (len > packet_len) {
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387 | CHAPDEBUG(LOG_INFO, ("ChapInput: rcvd short packet.\n"));
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388 | return;
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389 | }
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390 | len -= CHAP_HEADERLEN;
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391 |
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392 | /*
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393 | * Action depends on code (as in fact it usually does :-).
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394 | */
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395 | switch (code) {
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396 | case CHAP_CHALLENGE:
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397 | ChapReceiveChallenge(cstate, inp, id, len);
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398 | break;
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399 |
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400 | case CHAP_RESPONSE:
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401 | ChapReceiveResponse(cstate, inp, id, len);
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402 | break;
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403 |
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404 | case CHAP_FAILURE:
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405 | ChapReceiveFailure(cstate, inp, id, len);
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406 | break;
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407 |
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408 | case CHAP_SUCCESS:
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409 | ChapReceiveSuccess(cstate, inp, id, len);
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410 | break;
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411 |
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412 | default: /* Need code reject? */
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413 | CHAPDEBUG(LOG_WARNING, ("Unknown CHAP code (%d) received.\n", code));
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414 | break;
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415 | }
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416 | }
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417 |
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418 |
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419 | /*
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420 | * ChapReceiveChallenge - Receive Challenge and send Response.
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421 | */
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422 | static void
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423 | ChapReceiveChallenge(chap_state *cstate, u_char *inp, u_char id, int len)
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424 | {
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425 | int rchallenge_len;
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426 | u_char *rchallenge;
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427 | int secret_len;
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428 | char secret[MAXSECRETLEN];
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429 | char rhostname[256];
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430 | MD5_CTX mdContext;
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431 | u_char hash[MD5_SIGNATURE_SIZE];
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432 |
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433 | CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: Rcvd id %d.\n", id));
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434 | if (cstate->clientstate == CHAPCS_CLOSED ||
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435 | cstate->clientstate == CHAPCS_PENDING) {
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436 | CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: in state %d\n",
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437 | cstate->clientstate));
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438 | return;
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439 | }
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440 |
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441 | if (len < 2) {
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442 | CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: rcvd short packet.\n"));
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443 | return;
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444 | }
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445 |
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446 | GETCHAR(rchallenge_len, inp);
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447 | len -= sizeof (u_char) + rchallenge_len; /* now name field length */
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448 | if (len < 0) {
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449 | CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: rcvd short packet.\n"));
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450 | return;
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451 | }
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452 | rchallenge = inp;
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453 | INCPTR(rchallenge_len, inp);
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454 |
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455 | if (len >= (int)sizeof(rhostname)) {
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456 | len = sizeof(rhostname) - 1;
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457 | }
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458 | BCOPY(inp, rhostname, len);
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459 | rhostname[len] = '\000';
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460 |
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461 | CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: received name field '%s'\n",
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462 | rhostname));
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463 |
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464 | /* Microsoft doesn't send their name back in the PPP packet */
|
---|
465 | if (ppp_settings.remote_name[0] != 0 && (ppp_settings.explicit_remote || rhostname[0] == 0)) {
|
---|
466 | strncpy(rhostname, ppp_settings.remote_name, sizeof(rhostname));
|
---|
467 | rhostname[sizeof(rhostname) - 1] = 0;
|
---|
468 | CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: using '%s' as remote name\n",
|
---|
469 | rhostname));
|
---|
470 | }
|
---|
471 |
|
---|
472 | /* get secret for authenticating ourselves with the specified host */
|
---|
473 | if (!get_secret(cstate->unit, cstate->resp_name, rhostname,
|
---|
474 | secret, &secret_len, 0)) {
|
---|
475 | secret_len = 0; /* assume null secret if can't find one */
|
---|
476 | CHAPDEBUG(LOG_WARNING, ("No CHAP secret found for authenticating us to %s\n",
|
---|
477 | rhostname));
|
---|
478 | }
|
---|
479 |
|
---|
480 | /* cancel response send timeout if necessary */
|
---|
481 | if (cstate->clientstate == CHAPCS_RESPONSE) {
|
---|
482 | UNTIMEOUT(ChapResponseTimeout, cstate);
|
---|
483 | }
|
---|
484 |
|
---|
485 | cstate->resp_id = id;
|
---|
486 | cstate->resp_transmits = 0;
|
---|
487 |
|
---|
488 | /* generate MD based on negotiated type */
|
---|
489 | switch (cstate->resp_type) {
|
---|
490 |
|
---|
491 | case CHAP_DIGEST_MD5:
|
---|
492 | MD5Init(&mdContext);
|
---|
493 | MD5Update(&mdContext, &cstate->resp_id, 1);
|
---|
494 | MD5Update(&mdContext, (u_char*)secret, secret_len);
|
---|
495 | MD5Update(&mdContext, rchallenge, rchallenge_len);
|
---|
496 | MD5Final(hash, &mdContext);
|
---|
497 | BCOPY(hash, cstate->response, MD5_SIGNATURE_SIZE);
|
---|
498 | cstate->resp_length = MD5_SIGNATURE_SIZE;
|
---|
499 | break;
|
---|
500 |
|
---|
501 | #if MSCHAP_SUPPORT
|
---|
502 | case CHAP_MICROSOFT:
|
---|
503 | ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len);
|
---|
504 | break;
|
---|
505 | #endif
|
---|
506 |
|
---|
507 | default:
|
---|
508 | CHAPDEBUG(LOG_INFO, ("unknown digest type %d\n", cstate->resp_type));
|
---|
509 | return;
|
---|
510 | }
|
---|
511 |
|
---|
512 | BZERO(secret, sizeof(secret));
|
---|
513 | ChapSendResponse(cstate);
|
---|
514 | }
|
---|
515 |
|
---|
516 |
|
---|
517 | /*
|
---|
518 | * ChapReceiveResponse - Receive and process response.
|
---|
519 | */
|
---|
520 | static void
|
---|
521 | ChapReceiveResponse(chap_state *cstate, u_char *inp, int id, int len)
|
---|
522 | {
|
---|
523 | u_char *remmd, remmd_len;
|
---|
524 | int secret_len, old_state;
|
---|
525 | int code;
|
---|
526 | char rhostname[256];
|
---|
527 | MD5_CTX mdContext;
|
---|
528 | char secret[MAXSECRETLEN];
|
---|
529 | u_char hash[MD5_SIGNATURE_SIZE];
|
---|
530 |
|
---|
531 | CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: Rcvd id %d.\n", id));
|
---|
532 |
|
---|
533 | if (cstate->serverstate == CHAPSS_CLOSED ||
|
---|
534 | cstate->serverstate == CHAPSS_PENDING) {
|
---|
535 | CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: in state %d\n",
|
---|
536 | cstate->serverstate));
|
---|
537 | return;
|
---|
538 | }
|
---|
539 |
|
---|
540 | if (id != cstate->chal_id) {
|
---|
541 | return; /* doesn't match ID of last challenge */
|
---|
542 | }
|
---|
543 |
|
---|
544 | /*
|
---|
545 | * If we have received a duplicate or bogus Response,
|
---|
546 | * we have to send the same answer (Success/Failure)
|
---|
547 | * as we did for the first Response we saw.
|
---|
548 | */
|
---|
549 | if (cstate->serverstate == CHAPSS_OPEN) {
|
---|
550 | ChapSendStatus(cstate, CHAP_SUCCESS);
|
---|
551 | return;
|
---|
552 | }
|
---|
553 | if (cstate->serverstate == CHAPSS_BADAUTH) {
|
---|
554 | ChapSendStatus(cstate, CHAP_FAILURE);
|
---|
555 | return;
|
---|
556 | }
|
---|
557 |
|
---|
558 | if (len < 2) {
|
---|
559 | CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: rcvd short packet.\n"));
|
---|
560 | return;
|
---|
561 | }
|
---|
562 | GETCHAR(remmd_len, inp); /* get length of MD */
|
---|
563 | remmd = inp; /* get pointer to MD */
|
---|
564 | INCPTR(remmd_len, inp);
|
---|
565 |
|
---|
566 | len -= sizeof (u_char) + remmd_len;
|
---|
567 | if (len < 0) {
|
---|
568 | CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: rcvd short packet.\n"));
|
---|
569 | return;
|
---|
570 | }
|
---|
571 |
|
---|
572 | UNTIMEOUT(ChapChallengeTimeout, cstate);
|
---|
573 |
|
---|
574 | if (len >= (int)sizeof(rhostname)) {
|
---|
575 | len = sizeof(rhostname) - 1;
|
---|
576 | }
|
---|
577 | BCOPY(inp, rhostname, len);
|
---|
578 | rhostname[len] = '\000';
|
---|
579 |
|
---|
580 | CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: received name field: %s\n",
|
---|
581 | rhostname));
|
---|
582 |
|
---|
583 | /*
|
---|
584 | * Get secret for authenticating them with us,
|
---|
585 | * do the hash ourselves, and compare the result.
|
---|
586 | */
|
---|
587 | code = CHAP_FAILURE;
|
---|
588 | if (!get_secret(cstate->unit, rhostname, cstate->chal_name,
|
---|
589 | secret, &secret_len, 1)) {
|
---|
590 | CHAPDEBUG(LOG_WARNING, ("No CHAP secret found for authenticating %s\n",
|
---|
591 | rhostname));
|
---|
592 | } else {
|
---|
593 | /* generate MD based on negotiated type */
|
---|
594 | switch (cstate->chal_type) {
|
---|
595 |
|
---|
596 | case CHAP_DIGEST_MD5: /* only MD5 is defined for now */
|
---|
597 | if (remmd_len != MD5_SIGNATURE_SIZE) {
|
---|
598 | break; /* it's not even the right length */
|
---|
599 | }
|
---|
600 | MD5Init(&mdContext);
|
---|
601 | MD5Update(&mdContext, &cstate->chal_id, 1);
|
---|
602 | MD5Update(&mdContext, (u_char*)secret, secret_len);
|
---|
603 | MD5Update(&mdContext, cstate->challenge, cstate->chal_len);
|
---|
604 | MD5Final(hash, &mdContext);
|
---|
605 |
|
---|
606 | /* compare local and remote MDs and send the appropriate status */
|
---|
607 | if (memcmp (hash, remmd, MD5_SIGNATURE_SIZE) == 0) {
|
---|
608 | code = CHAP_SUCCESS; /* they are the same! */
|
---|
609 | }
|
---|
610 | break;
|
---|
611 |
|
---|
612 | default:
|
---|
613 | CHAPDEBUG(LOG_INFO, ("unknown digest type %d\n", cstate->chal_type));
|
---|
614 | }
|
---|
615 | }
|
---|
616 |
|
---|
617 | BZERO(secret, sizeof(secret));
|
---|
618 | ChapSendStatus(cstate, code);
|
---|
619 |
|
---|
620 | if (code == CHAP_SUCCESS) {
|
---|
621 | old_state = cstate->serverstate;
|
---|
622 | cstate->serverstate = CHAPSS_OPEN;
|
---|
623 | if (old_state == CHAPSS_INITIAL_CHAL) {
|
---|
624 | auth_peer_success(cstate->unit, PPP_CHAP, rhostname, len);
|
---|
625 | }
|
---|
626 | if (cstate->chal_interval != 0) {
|
---|
627 | TIMEOUT(ChapRechallenge, cstate, cstate->chal_interval);
|
---|
628 | }
|
---|
629 | } else {
|
---|
630 | CHAPDEBUG(LOG_ERR, ("CHAP peer authentication failed\n"));
|
---|
631 | cstate->serverstate = CHAPSS_BADAUTH;
|
---|
632 | auth_peer_fail(cstate->unit, PPP_CHAP);
|
---|
633 | }
|
---|
634 | }
|
---|
635 |
|
---|
636 | /*
|
---|
637 | * ChapReceiveSuccess - Receive Success
|
---|
638 | */
|
---|
639 | static void
|
---|
640 | ChapReceiveSuccess(chap_state *cstate, u_char *inp, u_char id, int len)
|
---|
641 | {
|
---|
642 | LWIP_UNUSED_ARG(id);
|
---|
643 | LWIP_UNUSED_ARG(inp);
|
---|
644 |
|
---|
645 | CHAPDEBUG(LOG_INFO, ("ChapReceiveSuccess: Rcvd id %d.\n", id));
|
---|
646 |
|
---|
647 | if (cstate->clientstate == CHAPCS_OPEN) {
|
---|
648 | /* presumably an answer to a duplicate response */
|
---|
649 | return;
|
---|
650 | }
|
---|
651 |
|
---|
652 | if (cstate->clientstate != CHAPCS_RESPONSE) {
|
---|
653 | /* don't know what this is */
|
---|
654 | CHAPDEBUG(LOG_INFO, ("ChapReceiveSuccess: in state %d\n",
|
---|
655 | cstate->clientstate));
|
---|
656 | return;
|
---|
657 | }
|
---|
658 |
|
---|
659 | UNTIMEOUT(ChapResponseTimeout, cstate);
|
---|
660 |
|
---|
661 | /*
|
---|
662 | * Print message.
|
---|
663 | */
|
---|
664 | if (len > 0) {
|
---|
665 | PRINTMSG(inp, len);
|
---|
666 | }
|
---|
667 |
|
---|
668 | cstate->clientstate = CHAPCS_OPEN;
|
---|
669 |
|
---|
670 | auth_withpeer_success(cstate->unit, PPP_CHAP);
|
---|
671 | }
|
---|
672 |
|
---|
673 |
|
---|
674 | /*
|
---|
675 | * ChapReceiveFailure - Receive failure.
|
---|
676 | */
|
---|
677 | static void
|
---|
678 | ChapReceiveFailure(chap_state *cstate, u_char *inp, u_char id, int len)
|
---|
679 | {
|
---|
680 | LWIP_UNUSED_ARG(id);
|
---|
681 | LWIP_UNUSED_ARG(inp);
|
---|
682 |
|
---|
683 | CHAPDEBUG(LOG_INFO, ("ChapReceiveFailure: Rcvd id %d.\n", id));
|
---|
684 |
|
---|
685 | if (cstate->clientstate != CHAPCS_RESPONSE) {
|
---|
686 | /* don't know what this is */
|
---|
687 | CHAPDEBUG(LOG_INFO, ("ChapReceiveFailure: in state %d\n",
|
---|
688 | cstate->clientstate));
|
---|
689 | return;
|
---|
690 | }
|
---|
691 |
|
---|
692 | UNTIMEOUT(ChapResponseTimeout, cstate);
|
---|
693 |
|
---|
694 | /*
|
---|
695 | * Print message.
|
---|
696 | */
|
---|
697 | if (len > 0) {
|
---|
698 | PRINTMSG(inp, len);
|
---|
699 | }
|
---|
700 |
|
---|
701 | CHAPDEBUG(LOG_ERR, ("CHAP authentication failed\n"));
|
---|
702 | auth_withpeer_fail(cstate->unit, PPP_CHAP); /* lwip: just sets the PPP error code on this unit to PPPERR_AUTHFAIL */
|
---|
703 | }
|
---|
704 |
|
---|
705 |
|
---|
706 | /*
|
---|
707 | * ChapSendChallenge - Send an Authenticate challenge.
|
---|
708 | */
|
---|
709 | static void
|
---|
710 | ChapSendChallenge(chap_state *cstate)
|
---|
711 | {
|
---|
712 | u_char *outp;
|
---|
713 | int chal_len, name_len;
|
---|
714 | int outlen;
|
---|
715 |
|
---|
716 | chal_len = cstate->chal_len;
|
---|
717 | name_len = (int)strlen(cstate->chal_name);
|
---|
718 | outlen = CHAP_HEADERLEN + sizeof (u_char) + chal_len + name_len;
|
---|
719 | outp = outpacket_buf[cstate->unit];
|
---|
720 |
|
---|
721 | MAKEHEADER(outp, PPP_CHAP); /* paste in a CHAP header */
|
---|
722 |
|
---|
723 | PUTCHAR(CHAP_CHALLENGE, outp);
|
---|
724 | PUTCHAR(cstate->chal_id, outp);
|
---|
725 | PUTSHORT(outlen, outp);
|
---|
726 |
|
---|
727 | PUTCHAR(chal_len, outp); /* put length of challenge */
|
---|
728 | BCOPY(cstate->challenge, outp, chal_len);
|
---|
729 | INCPTR(chal_len, outp);
|
---|
730 |
|
---|
731 | BCOPY(cstate->chal_name, outp, name_len); /* append hostname */
|
---|
732 |
|
---|
733 | pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
|
---|
734 |
|
---|
735 | CHAPDEBUG(LOG_INFO, ("ChapSendChallenge: Sent id %d.\n", cstate->chal_id));
|
---|
736 |
|
---|
737 | TIMEOUT(ChapChallengeTimeout, cstate, cstate->timeouttime);
|
---|
738 | ++cstate->chal_transmits;
|
---|
739 | }
|
---|
740 |
|
---|
741 |
|
---|
742 | /*
|
---|
743 | * ChapSendStatus - Send a status response (ack or nak).
|
---|
744 | */
|
---|
745 | static void
|
---|
746 | ChapSendStatus(chap_state *cstate, int code)
|
---|
747 | {
|
---|
748 | u_char *outp;
|
---|
749 | int outlen, msglen;
|
---|
750 | char msg[256]; /* @todo: this can be a char*, no strcpy needed */
|
---|
751 |
|
---|
752 | if (code == CHAP_SUCCESS) {
|
---|
753 | strcpy(msg, "Welcome!");
|
---|
754 | } else {
|
---|
755 | strcpy(msg, "I don't like you. Go 'way.");
|
---|
756 | }
|
---|
757 | msglen = (int)strlen(msg);
|
---|
758 |
|
---|
759 | outlen = CHAP_HEADERLEN + msglen;
|
---|
760 | outp = outpacket_buf[cstate->unit];
|
---|
761 |
|
---|
762 | MAKEHEADER(outp, PPP_CHAP); /* paste in a header */
|
---|
763 |
|
---|
764 | PUTCHAR(code, outp);
|
---|
765 | PUTCHAR(cstate->chal_id, outp);
|
---|
766 | PUTSHORT(outlen, outp);
|
---|
767 | BCOPY(msg, outp, msglen);
|
---|
768 | pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
|
---|
769 |
|
---|
770 | CHAPDEBUG(LOG_INFO, ("ChapSendStatus: Sent code %d, id %d.\n", code,
|
---|
771 | cstate->chal_id));
|
---|
772 | }
|
---|
773 |
|
---|
774 | /*
|
---|
775 | * ChapGenChallenge is used to generate a pseudo-random challenge string of
|
---|
776 | * a pseudo-random length between min_len and max_len. The challenge
|
---|
777 | * string and its length are stored in *cstate, and various other fields of
|
---|
778 | * *cstate are initialized.
|
---|
779 | */
|
---|
780 |
|
---|
781 | static void
|
---|
782 | ChapGenChallenge(chap_state *cstate)
|
---|
783 | {
|
---|
784 | int chal_len;
|
---|
785 | u_char *ptr = cstate->challenge;
|
---|
786 | int i;
|
---|
787 |
|
---|
788 | /* pick a random challenge length between MIN_CHALLENGE_LENGTH and
|
---|
789 | MAX_CHALLENGE_LENGTH */
|
---|
790 | chal_len = (unsigned)
|
---|
791 | ((((magic() >> 16) *
|
---|
792 | (MAX_CHALLENGE_LENGTH - MIN_CHALLENGE_LENGTH)) >> 16)
|
---|
793 | + MIN_CHALLENGE_LENGTH);
|
---|
794 | LWIP_ASSERT("chal_len <= 0xff", chal_len <= 0xffff);
|
---|
795 | cstate->chal_len = (u_char)chal_len;
|
---|
796 | cstate->chal_id = ++cstate->id;
|
---|
797 | cstate->chal_transmits = 0;
|
---|
798 |
|
---|
799 | /* generate a random string */
|
---|
800 | for (i = 0; i < chal_len; i++ ) {
|
---|
801 | *ptr++ = (char) (magic() & 0xff);
|
---|
802 | }
|
---|
803 | }
|
---|
804 |
|
---|
805 | /*
|
---|
806 | * ChapSendResponse - send a response packet with values as specified
|
---|
807 | * in *cstate.
|
---|
808 | */
|
---|
809 | /* ARGSUSED */
|
---|
810 | static void
|
---|
811 | ChapSendResponse(chap_state *cstate)
|
---|
812 | {
|
---|
813 | u_char *outp;
|
---|
814 | int outlen, md_len, name_len;
|
---|
815 |
|
---|
816 | md_len = cstate->resp_length;
|
---|
817 | name_len = (int)strlen(cstate->resp_name);
|
---|
818 | outlen = CHAP_HEADERLEN + sizeof (u_char) + md_len + name_len;
|
---|
819 | outp = outpacket_buf[cstate->unit];
|
---|
820 |
|
---|
821 | MAKEHEADER(outp, PPP_CHAP);
|
---|
822 |
|
---|
823 | PUTCHAR(CHAP_RESPONSE, outp); /* we are a response */
|
---|
824 | PUTCHAR(cstate->resp_id, outp); /* copy id from challenge packet */
|
---|
825 | PUTSHORT(outlen, outp); /* packet length */
|
---|
826 |
|
---|
827 | PUTCHAR(md_len, outp); /* length of MD */
|
---|
828 | BCOPY(cstate->response, outp, md_len); /* copy MD to buffer */
|
---|
829 | INCPTR(md_len, outp);
|
---|
830 |
|
---|
831 | BCOPY(cstate->resp_name, outp, name_len); /* append our name */
|
---|
832 |
|
---|
833 | /* send the packet */
|
---|
834 | pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
|
---|
835 |
|
---|
836 | cstate->clientstate = CHAPCS_RESPONSE;
|
---|
837 | TIMEOUT(ChapResponseTimeout, cstate, cstate->timeouttime);
|
---|
838 | ++cstate->resp_transmits;
|
---|
839 | }
|
---|
840 |
|
---|
841 | #if PPP_ADDITIONAL_CALLBACKS
|
---|
842 | static char *ChapCodenames[] = {
|
---|
843 | "Challenge", "Response", "Success", "Failure"
|
---|
844 | };
|
---|
845 | /*
|
---|
846 | * ChapPrintPkt - print the contents of a CHAP packet.
|
---|
847 | */
|
---|
848 | static int
|
---|
849 | ChapPrintPkt( u_char *p, int plen, void (*printer) (void *, char *, ...), void *arg)
|
---|
850 | {
|
---|
851 | int code, id, len;
|
---|
852 | int clen, nlen;
|
---|
853 | u_char x;
|
---|
854 |
|
---|
855 | if (plen < CHAP_HEADERLEN) {
|
---|
856 | return 0;
|
---|
857 | }
|
---|
858 | GETCHAR(code, p);
|
---|
859 | GETCHAR(id, p);
|
---|
860 | GETSHORT(len, p);
|
---|
861 | if (len < CHAP_HEADERLEN || len > plen) {
|
---|
862 | return 0;
|
---|
863 | }
|
---|
864 |
|
---|
865 | if (code >= 1 && code <= sizeof(ChapCodenames) / sizeof(char *)) {
|
---|
866 | printer(arg, " %s", ChapCodenames[code-1]);
|
---|
867 | } else {
|
---|
868 | printer(arg, " code=0x%x", code);
|
---|
869 | }
|
---|
870 | printer(arg, " id=0x%x", id);
|
---|
871 | len -= CHAP_HEADERLEN;
|
---|
872 | switch (code) {
|
---|
873 | case CHAP_CHALLENGE:
|
---|
874 | case CHAP_RESPONSE:
|
---|
875 | if (len < 1) {
|
---|
876 | break;
|
---|
877 | }
|
---|
878 | clen = p[0];
|
---|
879 | if (len < clen + 1) {
|
---|
880 | break;
|
---|
881 | }
|
---|
882 | ++p;
|
---|
883 | nlen = len - clen - 1;
|
---|
884 | printer(arg, " <");
|
---|
885 | for (; clen > 0; --clen) {
|
---|
886 | GETCHAR(x, p);
|
---|
887 | printer(arg, "%.2x", x);
|
---|
888 | }
|
---|
889 | printer(arg, ">, name = %.*Z", nlen, p);
|
---|
890 | break;
|
---|
891 | case CHAP_FAILURE:
|
---|
892 | case CHAP_SUCCESS:
|
---|
893 | printer(arg, " %.*Z", len, p);
|
---|
894 | break;
|
---|
895 | default:
|
---|
896 | for (clen = len; clen > 0; --clen) {
|
---|
897 | GETCHAR(x, p);
|
---|
898 | printer(arg, " %.2x", x);
|
---|
899 | }
|
---|
900 | }
|
---|
901 |
|
---|
902 | return len + CHAP_HEADERLEN;
|
---|
903 | }
|
---|
904 | #endif /* PPP_ADDITIONAL_CALLBACKS */
|
---|
905 |
|
---|
906 | #endif /* CHAP_SUPPORT */
|
---|
907 |
|
---|
908 | #endif /* PPP_SUPPORT */
|
---|