1 | //auth.c: |
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2 | |
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3 | /* |
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4 | * Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2008-2011 |
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5 | * |
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6 | * This file is part of libroar a part of RoarAudio, |
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7 | * a cross-platform sound system for both, home and professional use. |
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8 | * See README for details. |
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9 | * |
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10 | * This file is free software; you can redistribute it and/or modify |
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11 | * it under the terms of the GNU General Public License version 3 |
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12 | * as published by the Free Software Foundation. |
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13 | * |
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14 | * libroar is distributed in the hope that it will be useful, |
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15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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17 | * GNU General Public License for more details. |
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18 | * |
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19 | * You should have received a copy of the GNU General Public License |
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20 | * along with this software; see the file COPYING. If not, write to |
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21 | * the Free Software Foundation, 51 Franklin Street, Fifth Floor, |
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22 | * Boston, MA 02110-1301, USA. |
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23 | * |
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24 | * NOTE for everyone want's to change something and send patches: |
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25 | * read README and HACKING! There a addition information on |
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26 | * the license of this document you need to read before you send |
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27 | * any patches. |
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28 | * |
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29 | * NOTE for uses of non-GPL (LGPL,...) software using libesd, libartsc |
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30 | * or libpulse*: |
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31 | * The libs libroaresd, libroararts and libroarpulse link this lib |
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32 | * and are therefore GPL. Because of this it may be illegal to use |
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33 | * them with any software that uses libesd, libartsc or libpulse*. |
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34 | */ |
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35 | |
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36 | #include "libroar.h" |
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37 | |
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38 | /* How auth works: |
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39 | * 0) set stage to zero |
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40 | * 1) get server address and local node name (from uname()) |
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41 | * 2) look up authfile/authdb/authservice for the server+local address + stage. |
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42 | * if no data was found send NONE-Auth. |
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43 | * 3) send data to server |
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44 | * 4) read answer from server |
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45 | * 5) if stage of server response is non-zero increment stage to server stage+1 |
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46 | * and repeat from step 2) |
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47 | * 6) check if we got an OK or an ERROR, return correct value |
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48 | */ |
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49 | |
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50 | /* The protocol: |
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51 | * Auth request: |
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52 | * Byte 0: auth type |
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53 | * Byte 1: stage |
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54 | * Byte 2: reserved (must be zero) |
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55 | * Byte 3: reserved (must be zero) |
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56 | * Byte 4-end: auth type depending data. |
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57 | * |
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58 | * If no data is to be send bytes 2 and 3 can be omitted. |
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59 | * If no data is to be send and stage is zero bytes 1, 2 and 3 can be omitted. |
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60 | * |
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61 | * Auth response: |
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62 | * The same as the auth request. |
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63 | * if the server sends an zero size message back it means the server accepted our connection |
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64 | * and no additional stage is needed. |
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65 | * if the message type is OK the server accepted our auth. |
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66 | * if the message type is ERROR the server rejected us. we may try other auth methods. |
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67 | * if the server accepted our data and the stage is non-zero we need to continue with the next |
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68 | * stage of the auth. |
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69 | * if the server rejected us the auth type value of the response is a suggested next auth type |
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70 | * we should try if possible. This may help the client to find a working auth type. |
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71 | */ |
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72 | |
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73 | /* The protocol by auth type: |
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74 | * |
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75 | * --- NONE: |
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76 | * No data is send, the server accepts the connect or rejects it depending on some |
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77 | * magic within the server. we do not care about this. |
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78 | * The data block is not used. |
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79 | * |
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80 | * --- COOKIE: |
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81 | * We send cookies for all stages the server ask us to provide a cookie. |
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82 | * if a cookie is wrong the server rejects us or asks us for another. |
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83 | * The cookie is send as binary data in the data block. |
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84 | * |
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85 | * --- TRUST: |
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86 | * We ask the server to auth us based on our UID/GID/PID. |
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87 | * The server may reject this because we are not allowed or because it is not |
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88 | * supported by the transport. |
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89 | * If we get rejected we may try to continue with IDENT then RHOST before we use NONE. |
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90 | * The data block is not used. |
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91 | * |
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92 | * --- PASSWORD: |
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93 | * This is technically the same as COOKIE just that the cookie is limited to |
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94 | * printable ASCII chars and that the user should be asked to provide the password. |
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95 | * This may be done via a GUI popup window. |
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96 | * |
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97 | * --- SYSUSER: |
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98 | * We provide a Username + Password for a system user. |
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99 | * The data block contains of two main parts: |
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100 | * The first part is a one byte long subtype. |
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101 | * The value must be 0x01 for username+password. |
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102 | * future versions may define other types. |
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103 | * the second part is the actual data block. |
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104 | * for username+password it is splited into two fields, both terminated with \0. |
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105 | * the first is the username the last one the password as clear text. |
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106 | * Example: char data[] = "\001MyUser\0MyPassword\0"; |
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107 | * |
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108 | * --- OPENPGP_SIGN: |
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109 | * |
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110 | * --- OPENPGP_ENCRYPT: |
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111 | * |
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112 | * --- OPENPGP_AUTH: |
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113 | * |
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114 | * --- KERBEROS: |
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115 | * We use Kerberos to auth. |
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116 | * |
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117 | * --- RHOST: |
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118 | * The server is asked to auth us based on our source address. |
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119 | * The data block is not used. |
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120 | * |
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121 | * --- XAUTH: |
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122 | * We send an X11 Cookie. |
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123 | * |
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124 | * --- IDENT: |
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125 | * The server is asked to auth us based on our source address using the IDENT protocol. |
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126 | * The data block is not used. |
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127 | * |
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128 | */ |
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129 | |
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130 | static int roar_auth_ask_server (struct roar_connection * con, struct roar_auth_message * authmes) { |
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131 | struct roar_error_frame error_frame; |
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132 | struct roar_message mes; |
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133 | char * header = mes.data; |
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134 | int ret; |
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135 | |
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136 | memset(&mes, 0, sizeof(struct roar_message)); // make valgrind happy! |
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137 | |
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138 | mes.cmd = ROAR_CMD_AUTH; |
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139 | mes.datalen = 4; |
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140 | |
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141 | header[0] = authmes->type; |
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142 | header[1] = authmes->stage; |
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143 | header[2] = authmes->reserved.c[0]; |
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144 | header[3] = authmes->reserved.c[1]; |
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145 | |
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146 | if ( (ret = roar_req(con, &mes, NULL)) == -1 ) { |
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147 | authmes->type = -1; |
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148 | return -1; |
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149 | } |
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150 | |
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151 | if ( mes.cmd != ROAR_CMD_OK ) { |
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152 | ret = -1; |
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153 | if ( roar_err_parsemsg(&mes, &error_frame) == -1 ) { |
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154 | authmes->type = -1; |
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155 | return -1; |
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156 | } |
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157 | |
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158 | header = error_frame.data; |
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159 | mes.datalen = error_frame.datalen; |
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160 | } |
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161 | |
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162 | if ( mes.datalen < 4 ) { |
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163 | memset(header+mes.datalen, 0, 4-mes.datalen); |
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164 | authmes->type = -1; |
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165 | } else { |
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166 | authmes->type = header[0]; |
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167 | } |
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168 | |
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169 | authmes->stage = header[1]; |
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170 | authmes->reserved.c[0] = header[2]; |
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171 | authmes->reserved.c[1] = header[3]; |
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172 | |
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173 | return ret; |
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174 | } |
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175 | |
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176 | static void roar_auth_mes_init(struct roar_auth_message * authmes, int type) { |
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177 | memset(authmes, 0, sizeof(struct roar_auth_message)); |
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178 | |
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179 | authmes->type = type; |
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180 | authmes->stage = 0; |
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181 | authmes->data = NULL; |
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182 | authmes->len = 0; |
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183 | } |
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184 | |
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185 | |
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186 | static int try_password (struct roar_connection * con, int * next) { |
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187 | struct roar_message mes; |
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188 | struct roar_auth_message authmes; |
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189 | char * pw; |
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190 | |
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191 | // TODO: add support for *next. |
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192 | |
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193 | roar_auth_mes_init(&authmes, ROAR_AUTH_T_PASSWORD); |
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194 | |
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195 | if ( roar_passwd_simple_ask_pw(&pw, "Password for RoarAudio Server?", NULL) == -1 ) { |
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196 | return -1; |
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197 | } |
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198 | |
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199 | authmes.len = strlen(pw); |
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200 | |
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201 | if ( roar_auth_init_mes(&mes, &authmes) == -1 ) { |
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202 | roar_mm_free(pw); |
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203 | return -1; |
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204 | } |
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205 | |
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206 | // do not use strcpy() because that would copy \0, too. |
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207 | memcpy(authmes.data, pw, authmes.len); |
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208 | |
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209 | roar_mm_free(pw); |
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210 | |
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211 | if ( roar_req(con, &mes, NULL) == -1 ) |
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212 | return -1; |
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213 | |
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214 | if ( mes.cmd != ROAR_CMD_OK ) |
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215 | return -1; |
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216 | |
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217 | if ( roar_auth_from_mes(&authmes, &mes, NULL) == -1 ) |
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218 | return -1; |
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219 | |
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220 | if ( authmes.stage == 0 ) |
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221 | return 0; |
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222 | |
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223 | return -1; |
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224 | } |
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225 | |
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226 | #define _EOL ROAR_AUTH_T_AUTO |
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227 | int roar_auth (struct roar_connection * con) { |
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228 | struct roar_auth_message authmes; |
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229 | int ret; |
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230 | int i; |
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231 | int cur, next; |
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232 | int done; |
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233 | int ltt[] = { |
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234 | ROAR_AUTH_T_TRUST, |
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235 | ROAR_AUTH_T_IDENT, |
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236 | ROAR_AUTH_T_RHOST, |
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237 | // ROAR_AUTH_T_PASSWORD, |
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238 | ROAR_AUTH_T_NONE, |
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239 | _EOL |
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240 | }; |
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241 | |
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242 | for (i = 0; ltt[i] != _EOL; i++) { |
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243 | next = ltt[i]; |
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244 | while (next != -1) { |
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245 | done = 1; |
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246 | |
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247 | cur = next; |
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248 | next = -1; |
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249 | |
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250 | switch (cur) { |
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251 | case ROAR_AUTH_T_PASSWORD: |
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252 | if ( (ret = try_password(con, &next)) == -1 ) |
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253 | done = 0; |
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254 | break; |
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255 | case ROAR_AUTH_T_TRUST: |
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256 | case ROAR_AUTH_T_IDENT: |
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257 | case ROAR_AUTH_T_RHOST: |
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258 | case ROAR_AUTH_T_NONE: |
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259 | roar_auth_mes_init(&authmes, ltt[i]); |
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260 | if ( (ret = roar_auth_ask_server(con, &authmes)) == -1 ) |
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261 | done = 0; |
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262 | |
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263 | next = authmes.type; |
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264 | break; |
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265 | default: /* Bad error! */ |
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266 | return -1; |
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267 | break; |
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268 | } |
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269 | |
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270 | if ( authmes.stage != 0 ) |
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271 | done = 0; |
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272 | |
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273 | if ( done ) |
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274 | return 0; |
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275 | } |
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276 | } |
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277 | |
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278 | return -1; |
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279 | } |
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280 | |
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281 | |
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282 | int roar_auth_from_mes(struct roar_auth_message * ames, struct roar_message * mes, void * data) { |
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283 | void * ibuf; |
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284 | char header[4] = {0, 0, 0, 0}; |
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285 | |
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286 | if ( ames == NULL || mes == NULL ) |
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287 | return -1; |
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288 | |
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289 | if ( data != NULL ) { |
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290 | ibuf = data; |
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291 | } else { |
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292 | ibuf = mes->data; |
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293 | } |
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294 | |
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295 | memset(ames, 0, sizeof(struct roar_auth_message)); |
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296 | |
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297 | memcpy(header, ibuf, mes->datalen < 4 ? mes->datalen : 4); |
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298 | |
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299 | ames->type = header[0]; |
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300 | ames->stage = header[1]; |
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301 | ames->reserved.c[0] = header[2]; |
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302 | ames->reserved.c[1] = header[3]; |
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303 | |
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304 | if ( mes->datalen > 4 ) { |
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305 | ames->data = ibuf + 4; |
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306 | ames->len = mes->datalen - 4; |
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307 | } else { |
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308 | ames->data = NULL; |
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309 | ames->len = 0; |
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310 | } |
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311 | |
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312 | return 0; |
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313 | } |
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314 | |
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315 | int roar_auth_to_mes(struct roar_message * mes, void ** data, struct roar_auth_message * ames) { |
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316 | char * obuf; |
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317 | |
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318 | if ( mes == NULL || ames == NULL ) |
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319 | return -1; |
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320 | |
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321 | if ( data != NULL ) |
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322 | *data = NULL; |
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323 | |
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324 | memset(mes, 0, sizeof(struct roar_message)); |
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325 | |
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326 | mes->cmd = ROAR_CMD_AUTH; |
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327 | |
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328 | if ( (ames->len + 4) > sizeof(mes->data) ) { |
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329 | *data = malloc(ames->len + 4); |
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330 | if ( *data == NULL ) |
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331 | return -1; |
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332 | obuf = *data; |
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333 | } else { |
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334 | obuf = mes->data; |
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335 | } |
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336 | |
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337 | obuf[0] = ames->type; |
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338 | obuf[1] = ames->stage; |
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339 | obuf[2] = ames->reserved.c[0]; |
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340 | obuf[3] = ames->reserved.c[1]; |
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341 | |
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342 | memcpy(obuf + 8, ames->data, ames->len); |
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343 | |
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344 | mes->datalen = ames->len + 4; |
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345 | |
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346 | return 0; |
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347 | } |
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348 | |
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349 | int roar_auth_init_mes(struct roar_message * mes, struct roar_auth_message * ames) { |
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350 | if ( mes == NULL || ames == NULL ) |
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351 | return -1; |
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352 | |
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353 | if ( (ames->len + 4) > sizeof(mes->data) ) |
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354 | return -1; |
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355 | |
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356 | memset(mes, 0, sizeof(struct roar_message)); |
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357 | |
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358 | mes->cmd = ROAR_CMD_AUTH; |
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359 | |
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360 | mes->data[0] = ames->type; |
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361 | mes->data[1] = ames->stage; |
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362 | mes->data[2] = ames->reserved.c[0]; |
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363 | mes->data[3] = ames->reserved.c[1]; |
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364 | |
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365 | ames->data = &(mes->data[4]); |
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366 | |
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367 | mes->datalen = ames->len + 4; |
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368 | |
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369 | return 0; |
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370 | } |
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371 | |
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372 | |
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373 | |
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374 | // String functions: |
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375 | static struct { |
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376 | int type; |
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377 | const char * name; |
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378 | } _g_authts[] = { |
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379 | // grep ^'#define ROAR_AUTH_T_' auth.h | while read d t d; do n=$(cut -d_ -f4 <<<$t | tr A-Z a-z); printf ' {%-28s %-10s},\n' $t, \"$n\"; done |
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380 | {ROAR_AUTH_T_NONE, "none" }, |
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381 | {ROAR_AUTH_T_COOKIE, "cookie" }, |
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382 | {ROAR_AUTH_T_TRUST, "trust" }, |
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383 | {ROAR_AUTH_T_PASSWORD, "password"}, |
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384 | {ROAR_AUTH_T_SYSUSER, "sysuser" }, |
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385 | {ROAR_AUTH_T_OPENPGP_SIGN, "openpgp" }, |
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386 | {ROAR_AUTH_T_OPENPGP_ENCRYPT, "openpgp" }, |
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387 | {ROAR_AUTH_T_OPENPGP_AUTH, "openpgp" }, |
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388 | {ROAR_AUTH_T_KERBEROS, "kerberos"}, |
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389 | {ROAR_AUTH_T_RHOST, "rhost" }, |
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390 | {ROAR_AUTH_T_XAUTH, "xauth" }, |
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391 | {ROAR_AUTH_T_IDENT, "ident" }, |
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392 | {-1, NULL} |
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393 | }; |
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394 | |
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395 | int roar_str2autht(const char * str) { |
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396 | int i; |
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397 | |
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398 | for (i = 0; _g_authts[i].name != NULL; i++) |
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399 | if ( !strcasecmp(_g_authts[i].name, str) ) |
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400 | return _g_authts[i].type; |
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401 | |
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402 | return -1; |
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403 | } |
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404 | |
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405 | const char * roar_autht2str(const int auth) { |
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406 | int i; |
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407 | |
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408 | for (i = 0; _g_authts[i].name != NULL; i++) |
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409 | if ( _g_authts[i].type == auth ) |
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410 | return _g_authts[i].name; |
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411 | |
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412 | return "(UNKNOWN)"; |
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413 | } |
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414 | |
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415 | //ll |
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