base/mac/authorization_util.mm

   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 #include "base/mac/authorization_util.h"
   6
   7 #import <Foundation/Foundation.h>
   8 #include <sys/wait.h>
   9
  10 #include <string>
  11
  12 #include "base/basictypes.h"
  13 #include "base/logging.h"
  14 #include "base/mac/bundle_locations.h"
  15 #include "base/mac/mac_logging.h"
  16 #import "base/mac/mac_util.h"
  17 #include "base/mac/scoped_authorizationref.h"
  18 #include "base/posix/eintr_wrapper.h"
  19 #include "base/strings/string_number_conversions.h"
  20 #include "base/strings/string_util.h"
  21
  22 namespace base {
  23 namespace mac {
  24
  25 AuthorizationRef GetAuthorizationRightsWithPrompt(
  26     AuthorizationRights* rights,
  27     CFStringRef prompt,
  28     AuthorizationFlags extraFlags) {
  29   // Create an empty AuthorizationRef.
  30   ScopedAuthorizationRef authorization;
  31   OSStatus status = AuthorizationCreate(NULL,
  32                                         kAuthorizationEmptyEnvironment,
  33                                         kAuthorizationFlagDefaults,
  34                                         &authorization);
  35   if (status != errAuthorizationSuccess) {
  36     OSSTATUS_LOG(ERROR, status) << "AuthorizationCreate";
  37     return NULL;
  38   }
  39
  40   AuthorizationFlags flags = kAuthorizationFlagDefaults |
  41                              kAuthorizationFlagInteractionAllowed |
  42                              kAuthorizationFlagExtendRights |
  43                              kAuthorizationFlagPreAuthorize |
  44                              extraFlags;
  45
  46   // product_logo_32.png is used instead of app.icns because Authorization
  47   // Services can't deal with .icns files.
  48   NSString* icon_path =
  49       [base::mac::FrameworkBundle() pathForResource:@"product_logo_32"
  50                                              ofType:@"png"];
  51   const char* icon_path_c = [icon_path fileSystemRepresentation];
  52   size_t icon_path_length = icon_path_c ? strlen(icon_path_c) : 0;
  53
  54   // The OS will append " Type an administrator's name and password to allow
  55   // <CFBundleDisplayName> to make changes."
  56   NSString* prompt_ns = base::mac::CFToNSCast(prompt);
  57   const char* prompt_c = [prompt_ns UTF8String];
  58   size_t prompt_length = prompt_c ? strlen(prompt_c) : 0;
  59
  60   AuthorizationItem environment_items[] = {
  61     {kAuthorizationEnvironmentIcon, icon_path_length, (void*)icon_path_c, 0},
  62     {kAuthorizationEnvironmentPrompt, prompt_length, (void*)prompt_c, 0}
  63   };
  64
  65   AuthorizationEnvironment environment = {arraysize(environment_items),
  66                                           environment_items};
  67
  68   status = AuthorizationCopyRights(authorization,
  69                                    rights,
  70                                    &environment,
  71                                    flags,
  72                                    NULL);
  73
  74   if (status != errAuthorizationSuccess) {
  75     if (status != errAuthorizationCanceled) {
  76       OSSTATUS_LOG(ERROR, status) << "AuthorizationCopyRights";
  77     }
  78     return NULL;
  79   }
  80
  81   return authorization.release();
  82 }
  83
  84 AuthorizationRef AuthorizationCreateToRunAsRoot(CFStringRef prompt) {
  85   // Specify the "system.privilege.admin" right, which allows
  86   // AuthorizationExecuteWithPrivileges to run commands as root.
  87   AuthorizationItem right_items[] = {
  88     {kAuthorizationRightExecute, 0, NULL, 0}
  89   };
  90   AuthorizationRights rights = {arraysize(right_items), right_items};
  91
  92   return GetAuthorizationRightsWithPrompt(&rights, prompt, 0);
  93 }
  94
  95 OSStatus ExecuteWithPrivilegesAndGetPID(AuthorizationRef authorization,
  96                                         const char* tool_path,
  97                                         AuthorizationFlags options,
  98                                         const char** arguments,
  99                                         FILE** pipe,
 100                                         pid_t* pid) {
 101   // pipe may be NULL, but this function needs one.  In that case, use a local
 102   // pipe.
 103   FILE* local_pipe;
 104   FILE** pipe_pointer;
 105   if (pipe) {
 106     pipe_pointer = pipe;
 107   } else {
 108     pipe_pointer = &local_pipe;
 109   }
 110
 111   // AuthorizationExecuteWithPrivileges wants |char* const*| for |arguments|,
 112   // but it doesn't actually modify the arguments, and that type is kind of
 113   // silly and callers probably aren't dealing with that.  Put the cast here
 114   // to make things a little easier on callers.
 115   OSStatus status = AuthorizationExecuteWithPrivileges(authorization,
 116                                                        tool_path,
 117                                                        options,
 118                                                        (char* const*)arguments,
 119                                                        pipe_pointer);
 120   if (status != errAuthorizationSuccess) {
 121     return status;
 122   }
 123
 124   int line_pid = -1;
 125   size_t line_length = 0;
 126   char* line_c = fgetln(*pipe_pointer, &line_length);
 127   if (line_c) {
 128     if (line_length > 0 && line_c[line_length - 1] == '\n') {
 129       // line_c + line_length is the start of the next line if there is one.
 130       // Back up one character.
 131       --line_length;
 132     }
 133     std::string line(line_c, line_length);
 134     if (!base::StringToInt(line, &line_pid)) {
 135       // StringToInt may have set line_pid to something, but if the conversion
 136       // was imperfect, use -1.
 137       LOG(ERROR) << "ExecuteWithPrivilegesAndGetPid: funny line: " << line;
 138       line_pid = -1;
 139     }
 140   } else {
 141     LOG(ERROR) << "ExecuteWithPrivilegesAndGetPid: no line";
 142   }
 143
 144   if (!pipe) {
 145     fclose(*pipe_pointer);
 146   }
 147
 148   if (pid) {
 149     *pid = line_pid;
 150   }
 151
 152   return status;
 153 }
 154
 155 OSStatus ExecuteWithPrivilegesAndWait(AuthorizationRef authorization,
 156                                       const char* tool_path,
 157                                       AuthorizationFlags options,
 158                                       const char** arguments,
 159                                       FILE** pipe,
 160                                       int* exit_status) {
 161   pid_t pid;
 162   OSStatus status = ExecuteWithPrivilegesAndGetPID(authorization,
 163                                                    tool_path,
 164                                                    options,
 165                                                    arguments,
 166                                                    pipe,
 167                                                    &pid);
 168   if (status != errAuthorizationSuccess) {
 169     return status;
 170   }
 171
 172   // exit_status may be NULL, but this function needs it.  In that case, use a
 173   // local version.
 174   int local_exit_status;
 175   int* exit_status_pointer;
 176   if (exit_status) {
 177     exit_status_pointer = exit_status;
 178   } else {
 179     exit_status_pointer = &local_exit_status;
 180   }
 181
 182   if (pid != -1) {
 183     pid_t wait_result = HANDLE_EINTR(waitpid(pid, exit_status_pointer, 0));
 184     if (wait_result != pid) {
 185       PLOG(ERROR) << "waitpid";
 186       *exit_status_pointer = -1;
 187     }
 188   } else {
 189     *exit_status_pointer = -1;
 190   }
 191
 192   return status;
 193 }
 194
 195 }  // namespace mac
 196 }  // namespace base