rlz/win/lib/machine_deal.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 // Library functions related to the OEM Deal Confirmation Code.
   6
   7 #include "rlz/win/lib/machine_deal.h"
   8
   9 #include <windows.h>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/strings/string_split.h"
  15 #include "base/strings/string_util.h"
  16 #include "base/strings/stringprintf.h"
  17 #include "base/win/registry.h"
  18 #include "rlz/lib/assert.h"
  19 #include "rlz/lib/lib_values.h"
  20 #include "rlz/win/lib/lib_mutex.h"
  21 #include "rlz/win/lib/registry_util.h"
  22 #include "rlz/win/lib/rlz_value_store_registry.h"
  23
  24 const wchar_t kDccValueName[]             = L"DCC";
  25
  26 namespace {
  27
  28 // Current DCC can only uses [a-zA-Z0-9_-!@$*();.<>,:]
  29 // We will be more liberal and allow some additional chars, but not url meta
  30 // chars.
  31 bool IsGoodDccChar(char ch) {
  32   if (IsAsciiAlpha(ch) || IsAsciiDigit(ch))
  33     return true;
  34
  35   switch (ch) {
  36     case '_':
  37     case '-':
  38     case '!':
  39     case '@':
  40     case '$':
  41     case '*':
  42     case '(':
  43     case ')':
  44     case ';':
  45     case '.':
  46     case '<':
  47     case '>':
  48     case ',':
  49     case ':':
  50       return true;
  51   }
  52
  53   return false;
  54 }
  55
  56 // This function will remove bad rlz chars and also limit the max rlz to some
  57 // reasonable size. It also assumes that normalized_dcc is at least
  58 // kMaxDccLength+1 long.
  59 void NormalizeDcc(const char* raw_dcc, char* normalized_dcc) {
  60   int index = 0;
  61   for (; raw_dcc[index] != 0 && index < rlz_lib::kMaxDccLength; ++index) {
  62     char current = raw_dcc[index];
  63     if (IsGoodDccChar(current)) {
  64       normalized_dcc[index] = current;
  65     } else {
  66       normalized_dcc[index] = '.';
  67     }
  68   }
  69
  70   normalized_dcc[index] = 0;
  71 }
  72
  73 bool GetResponseLine(const char* response_text, int response_length,
  74                      int* search_index, std::string* response_line) {
  75   if (!response_line || !search_index || *search_index > response_length)
  76     return false;
  77
  78   response_line->clear();
  79
  80   if (*search_index < 0)
  81     return false;
  82
  83   int line_begin = *search_index;
  84   const char* line_end = strchr(response_text + line_begin, '\n');
  85
  86   if (line_end == NULL || line_end - response_text > response_length) {
  87     line_end = response_text + response_length;
  88     *search_index = -1;
  89   } else {
  90     *search_index = line_end - response_text + 1;
  91   }
  92
  93   response_line->assign(response_text + line_begin,
  94                         line_end - response_text - line_begin);
  95   return true;
  96 }
  97
  98 bool GetResponseValue(const std::string& response_line,
  99                       const std::string& response_key,
 100                       std::string* value) {
 101   if (!value)
 102     return false;
 103
 104   value->clear();
 105
 106   if (!StartsWithASCII(response_line, response_key, true))
 107     return false;
 108
 109   std::vector<std::string> tokens;
 110   base::SplitString(response_line, ':', &tokens);
 111   if (tokens.size() != 2)
 112     return false;
 113
 114   // The first token is the key, the second is the value.  The value is already
 115   // trimmed for whitespace.
 116   *value = tokens[1];
 117   return true;
 118 }
 119
 120 }  // namespace anonymous
 121
 122 namespace rlz_lib {
 123
 124 bool MachineDealCode::Set(const char* dcc) {
 125   LibMutex lock;
 126   if (lock.failed())
 127     return false;
 128
 129   // TODO: if (!ProcessInfo::CanWriteMachineKey()) return false;
 130
 131   // Validate the new dcc value.
 132   size_t length = strlen(dcc);
 133   if (length >  kMaxDccLength) {
 134     ASSERT_STRING("MachineDealCode::Set: DCC length is exceeds max allowed.");
 135     return false;
 136   }
 137
 138   base::win::RegKey hklm_key(HKEY_LOCAL_MACHINE,
 139                              RlzValueStoreRegistry::GetWideLibKeyName().c_str(),
 140                              KEY_READ | KEY_WRITE | KEY_WOW64_32KEY);
 141   if (!hklm_key.Valid()) {
 142     ASSERT_STRING("MachineDealCode::Set: Unable to create / open machine key."
 143                   " Did you call rlz_lib::CreateMachineState()?");
 144     return false;
 145   }
 146
 147   char normalized_dcc[kMaxDccLength + 1];
 148   NormalizeDcc(dcc, normalized_dcc);
 149   VERIFY(length == strlen(normalized_dcc));
 150
 151   // Write the DCC to HKLM.  Note that we need to include the null character
 152   // when writing the string.
 153   if (!RegKeyWriteValue(hklm_key, kDccValueName, normalized_dcc)) {
 154     ASSERT_STRING("MachineDealCode::Set: Could not write the DCC value");
 155     return false;
 156   }
 157
 158   return true;
 159 }
 160
 161 bool MachineDealCode::GetNewCodeFromPingResponse(const char* response,
 162     bool* has_new_dcc, char* new_dcc, int new_dcc_size) {
 163   if (!has_new_dcc || !new_dcc || !new_dcc_size)
 164     return false;
 165
 166   *has_new_dcc = false;
 167   new_dcc[0] = 0;
 168
 169   int response_length = -1;
 170   if (!IsPingResponseValid(response, &response_length))
 171     return false;
 172
 173   // Get the current DCC value to compare to later)
 174   char stored_dcc[kMaxDccLength + 1];
 175   if (!Get(stored_dcc, arraysize(stored_dcc)))
 176     stored_dcc[0] = 0;
 177
 178   int search_index = 0;
 179   std::string response_line;
 180   std::string new_dcc_value;
 181   bool old_dcc_confirmed = false;
 182   const std::string dcc_cgi(kDccCgiVariable);
 183   const std::string dcc_cgi_response(kSetDccResponseVariable);
 184   while (GetResponseLine(response, response_length, &search_index,
 185                          &response_line)) {
 186     std::string value;
 187
 188     if (!old_dcc_confirmed &&
 189         GetResponseValue(response_line, dcc_cgi, &value)) {
 190       // This is the old DCC confirmation - should match value in registry.
 191       if (value != stored_dcc)
 192         return false;  // Corrupted DCC - ignore this response.
 193       else
 194         old_dcc_confirmed = true;
 195       continue;
 196     }
 197
 198     if (!(*has_new_dcc) &&
 199         GetResponseValue(response_line, dcc_cgi_response, &value)) {
 200       // This is the new DCC.
 201       if (value.size() > kMaxDccLength) continue;  // Too long
 202       *has_new_dcc = true;
 203       new_dcc_value = value;
 204     }
 205   }
 206
 207   old_dcc_confirmed |= (NULL == stored_dcc[0]);
 208
 209   base::strlcpy(new_dcc, new_dcc_value.c_str(), new_dcc_size);
 210   return old_dcc_confirmed;
 211 }
 212
 213 bool MachineDealCode::SetFromPingResponse(const char* response) {
 214   bool has_new_dcc = false;
 215   char new_dcc[kMaxDccLength + 1];
 216
 217   bool response_valid = GetNewCodeFromPingResponse(
 218       response, &has_new_dcc, new_dcc, arraysize(new_dcc));
 219
 220   if (response_valid && has_new_dcc)
 221     return Set(new_dcc);
 222
 223   return response_valid;
 224 }
 225
 226 bool MachineDealCode::GetAsCgi(char* cgi, int cgi_size) {
 227   if (!cgi || cgi_size <= 0) {
 228     ASSERT_STRING("MachineDealCode::GetAsCgi: Invalid buffer");
 229     return false;
 230   }
 231
 232   cgi[0] = 0;
 233
 234   std::string cgi_arg;
 235   base::StringAppendF(&cgi_arg, "%s=", kDccCgiVariable);
 236   int cgi_arg_length = cgi_arg.size();
 237
 238   if (cgi_arg_length >= cgi_size) {
 239     ASSERT_STRING("MachineDealCode::GetAsCgi: Insufficient buffer size");
 240     return false;
 241   }
 242
 243   base::strlcpy(cgi, cgi_arg.c_str(), cgi_size);
 244
 245   if (!Get(cgi + cgi_arg_length, cgi_size - cgi_arg_length)) {
 246     cgi[0] = 0;
 247     return false;
 248   }
 249   return true;
 250 }
 251
 252 bool MachineDealCode::Get(char* dcc, int dcc_size) {
 253   LibMutex lock;
 254   if (lock.failed())
 255     return false;
 256
 257   if (!dcc || dcc_size <= 0) {
 258     ASSERT_STRING("MachineDealCode::Get: Invalid buffer");
 259     return false;
 260   }
 261
 262   dcc[0] = 0;
 263
 264   base::win::RegKey dcc_key(HKEY_LOCAL_MACHINE,
 265                             RlzValueStoreRegistry::GetWideLibKeyName().c_str(),
 266                             KEY_READ | KEY_WOW64_32KEY);
 267   if (!dcc_key.Valid())
 268     return false;  // no DCC key.
 269
 270   size_t size = dcc_size;
 271   if (!RegKeyReadValue(dcc_key, kDccValueName, dcc, &size)) {
 272     ASSERT_STRING("MachineDealCode::Get: Insufficient buffer size");
 273     dcc[0] = 0;
 274     return false;
 275   }
 276
 277   return true;
 278 }
 279
 280 bool MachineDealCode::Clear() {
 281   base::win::RegKey dcc_key(HKEY_LOCAL_MACHINE,
 282                             RlzValueStoreRegistry::GetWideLibKeyName().c_str(),
 283                             KEY_READ | KEY_WRITE | KEY_WOW64_32KEY);
 284   if (!dcc_key.Valid())
 285     return false;  // no DCC key.
 286
 287   dcc_key.DeleteValue(kDccValueName);
 288
 289   // Verify deletion.
 290   wchar_t dcc[kMaxDccLength + 1];
 291   DWORD dcc_size = arraysize(dcc);
 292   if (dcc_key.ReadValue(kDccValueName, dcc, &dcc_size, NULL) == ERROR_SUCCESS) {
 293     ASSERT_STRING("MachineDealCode::Clear: Could not delete the DCC value.");
 294     return false;
 295   }
 296
 297   return true;
 298 }
 299
 300 }  // namespace rlz_lib