utilities/src/SecFileLocations.c

   1 /*
   2  * Copyright (c) 2012-2013 Apple, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 //
  25 //  SecFileLocations.c
  26 //  utilities
  27 //
  28
  29 /*
  30     This file incorporates code from securityd_files.c (iOS) and iOSforOSX.c (OSX).
  31  */
  32
  33 #include <TargetConditionals.h>
  34 #include <AssertMacros.h>
  35 #include <CoreFoundation/CFPriv.h>
  36 #include <CoreFoundation/CFString.h>
  37 #include <CoreFoundation/CFURL.h>
  38 #include <CoreFoundation/CFUtilities.h>
  39 #include <utilities/SecCFWrappers.h>
  40 #include <utilities/SecCFRelease.h>
  41 #include <sys/stat.h>
  42 #include <uuid/uuid.h>
  43 #include <copyfile.h>
  44
  45 #include "SecFileLocations.h"
  46
  47 static CFURLRef sCustomHomeURL = NULL;
  48
  49 static CFURLRef SecCopyHomeURL(void)
  50 {
  51     // This returns a CFURLRef so that it can be passed as the second parameter
  52     // to CFURLCreateCopyAppendingPathComponent
  53
  54     CFURLRef homeURL = sCustomHomeURL;
  55     if (homeURL) {
  56         CFRetain(homeURL);
  57     } else {
  58 #if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
  59         // We would use CFCopyHomeDirectoryURL but it doesn't exist on MACOS.
  60         // This does the same.
  61         homeURL = CFCopyHomeDirectoryURLForUser(NULL);
  62 #else
  63         homeURL = CFCopyHomeDirectoryURL();
  64 #endif
  65     }
  66
  67     return homeURL;
  68 }
  69
  70 #if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
  71 static const char * get_host_uuid()
  72 {
  73     static uuid_string_t hostuuid = {};
  74     static dispatch_once_t onceToken;
  75     dispatch_once(&onceToken, ^{
  76         struct timespec timeout = {30, 0};
  77         uuid_t uuid = {};
  78         if (gethostuuid(uuid, &timeout) == 0) {
  79             uuid_unparse(uuid, hostuuid);
  80         } else {
  81             secerror("failed to get host uuid");
  82         }
  83     });
  84
  85     return hostuuid;
  86 }
  87
  88 static CFStringRef copy_keychain_uuid_path(CFURLRef keyChainBaseURL)
  89 {
  90     CFStringRef baseURLString = NULL;
  91     CFStringRef uuid_path = NULL;
  92
  93     require(keyChainBaseURL, done);
  94
  95     baseURLString = CFURLCopyFileSystemPath(keyChainBaseURL, kCFURLPOSIXPathStyle);
  96     require(baseURLString, done);
  97
  98     uuid_path = CFStringCreateWithFormat(kCFAllocatorDefault, NULL, CFSTR("%@/%s"), baseURLString, get_host_uuid());
  99
 100 done:
 101     CFReleaseSafe(baseURLString);
 102     return uuid_path;
 103 }
 104
 105 // See _kb_verify_create_path in securityd
 106 static bool keychain_verify_create_path(const char *keychainBasePath)
 107 {
 108     bool created = false;
 109     struct stat st_info = {};
 110     char new_path[PATH_MAX] = {};
 111     char kb_path[PATH_MAX] = {};
 112     snprintf(kb_path, sizeof(kb_path), "%s", keychainBasePath);
 113     if (lstat(kb_path, &st_info) == 0) {
 114         if (S_ISDIR(st_info.st_mode)) {
 115             created = true;
 116         } else {
 117             secerror("invalid directory at '%s' moving aside", kb_path);
 118             snprintf(new_path, sizeof(new_path), "%s-invalid", kb_path);
 119             unlink(new_path);
 120             if (rename(kb_path, new_path) != 0) {
 121                 secerror("failed to rename file: %s (%s)", kb_path, strerror(errno));
 122                 goto done;
 123             }
 124         }
 125     }
 126     if (!created) {
 127         require_action(mkpath_np(kb_path, 0700) == 0, done, secerror("could not create path: %s (%s)", kb_path, strerror(errno)));
 128         created = true;
 129     }
 130
 131 done:
 132     return created;
 133 }
 134 #endif /*(TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE)) */
 135
 136 static CFURLRef SecCopyBaseFilesURL()
 137 {
 138     CFURLRef baseURL = sCustomHomeURL;
 139     if (baseURL) {
 140         CFRetain(baseURL);
 141     } else {
 142 #if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED))
 143         baseURL = SecCopyHomeURL();
 144 #else
 145         baseURL = CFURLCreateWithFileSystemPath(NULL, CFSTR("/"), kCFURLPOSIXPathStyle, true);
 146 #endif
 147     }
 148     return baseURL;
 149 }
 150
 151 static CFURLRef SecCopyURLForFileInBaseDirectory(CFStringRef directoryPath, CFStringRef fileName)
 152 {
 153     CFURLRef fileURL = NULL;
 154     CFStringRef suffix = NULL;
 155     CFURLRef homeURL = SecCopyBaseFilesURL();
 156
 157     if (fileName)
 158         suffix = CFStringCreateWithFormat(kCFAllocatorDefault, NULL, CFSTR("%@/%@"), directoryPath, fileName);
 159     else
 160     if (directoryPath)
 161         suffix = CFStringCreateCopy(kCFAllocatorDefault, directoryPath);
 162
 163     if (homeURL && suffix)
 164         fileURL = CFURLCreateCopyAppendingPathComponent(kCFAllocatorDefault, homeURL, suffix, false);
 165     CFReleaseSafe(suffix);
 166     CFReleaseSafe(homeURL);
 167     return fileURL;
 168 }
 169
 170 CFURLRef SecCopyURLForFileInKeychainDirectory(CFStringRef fileName)
 171 {
 172 #if (TARGET_OS_MAC && !(TARGET_OS_EMBEDDED || TARGET_OS_IPHONE))
 173     // need to tack on uuid here
 174     Boolean isDirectory = (fileName == NULL);
 175     CFURLRef resultURL = NULL;
 176     CFStringRef resultStr = NULL;
 177     __block bool directoryExists = false;
 178
 179     CFURLRef keyChainBaseURL = SecCopyURLForFileInBaseDirectory(CFSTR("Library/Keychains"), NULL);
 180     CFStringRef uuid_path = copy_keychain_uuid_path(keyChainBaseURL);
 181     CFStringPerformWithCString(uuid_path, ^(const char *utf8Str) {
 182         directoryExists = keychain_verify_create_path(utf8Str);
 183     });
 184     require(directoryExists, done);
 185     if (fileName)
 186         resultStr = CFStringCreateWithFormat(kCFAllocatorDefault, NULL, CFSTR("%@/%@"), uuid_path, fileName);
 187     else
 188         resultStr = CFStringCreateCopy(kCFAllocatorDefault, uuid_path);
 189
 190 done:
 191     CFReleaseSafe(uuid_path);
 192     CFReleaseSafe(keyChainBaseURL);
 193     if (resultStr)
 194     {
 195         resultURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, resultStr, kCFURLPOSIXPathStyle, isDirectory);
 196         CFRelease(resultStr);
 197     }
 198     return resultURL;
 199 #else
 200     return SecCopyURLForFileInBaseDirectory(CFSTR("Library/Keychains"), fileName);
 201 #endif
 202 }
 203
 204 CFURLRef SecCopyURLForFileInPreferencesDirectory(CFStringRef fileName)
 205 {
 206     return SecCopyURLForFileInBaseDirectory(CFSTR("Library/Preferences"), fileName);
 207 }
 208
 209 void WithPathInKeychainDirectory(CFStringRef fileName, void(^operation)(const char *utf8String))
 210 {
 211     CFURLRef fileURL = SecCopyURLForFileInKeychainDirectory(fileName);
 212     UInt8 buffer[MAXPATHLEN];
 213     CFURLGetFileSystemRepresentation(fileURL, false, buffer, sizeof(buffer));
 214
 215     operation((const char*)buffer);
 216     CFRelease(fileURL);
 217 }
 218
 219 void SetCustomHomeURLString(CFStringRef home_path)
 220 {
 221     CFReleaseNull(sCustomHomeURL);
 222     if (home_path) {
 223         sCustomHomeURL = CFURLCreateWithFileSystemPath(NULL, home_path, kCFURLPOSIXPathStyle, true);
 224     }
 225 }
 226
 227 void SetCustomHomeURL(const char* path)
 228 {
 229     if (path) {
 230         CFStringRef path_cf = CFStringCreateWithCStringNoCopy(NULL, path, kCFStringEncodingUTF8, kCFAllocatorNull);
 231         SetCustomHomeURLString(path_cf);
 232         CFReleaseSafe(path_cf);
 233     } else {
 234         SetCustomHomeURLString(NULL);
 235     }
 236 }
 237
 238