tests/cases/test-getattrlist-dprotect.m

   1 /*
   2  * This test verifies the system calls that extract the data
   3  * protection class (A -> D) work properly in the face of a key bag
   4  * class roll.  Normally, the data protection class only occupies the
   5  * lower 5 bits of 32 bit space.  However, once we undergo a keyroll
   6  * one of the bits becomes hijacked to indicate whether or not the
   7  * file belongs to new (vs. old) key bag for the class keys.
   8  *
   9  * If our APIs are not working properly, this bit (or others) could be
  10  * exposed to userland — userland should only see the values 0 -> 32.
  11  */
  12
  13 #include <TargetConditionals.h>
  14
  15 #if (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR)
  16
  17 #include <unistd.h>
  18 #include <sys/stat.h>
  19 #include <sys/param.h>
  20 #include <sys/mount.h>
  21 #include <sys/mman.h>
  22 #include <sys/sysctl.h>
  23 #include <System/sys/fsgetpath.h>
  24 #include <MobileKeyBag/MobileKeyBag.h>
  25 #import <Foundation/Foundation.h>
  26 #import <Security/SecItemPriv.h>
  27
  28 #define CONFIG_PROTECT 1
  29
  30 #include "hfs-tests.h"
  31 #include "test-utils.h"
  32
  33 #include "../../core/hfs_fsctl.h"
  34
  35 TEST(getattrlist_dprotect, .run_as_root = true)
  36
  37 typedef enum generation_status {
  38     generation_current              = 1 << 0,
  39     generation_change_in_progress   = 1 << 1,
  40     generation_change_pending       = 1 << 2,
  41 } generation_status_t;
  42
  43 #define TEST_FILE       "/tmp/getattrlist_dprotect.data"
  44
  45 int run_getattrlist_dprotect(__unused test_ctx_t *ctx)
  46 {
  47         // The root file system needs to be HFS
  48         struct statfs sfs;
  49
  50         assert(statfs("/tmp", &sfs) == 0);
  51         if (strcmp(sfs.f_fstypename, "hfs")) {
  52                 printf("getatttrlist_dprotect needs hfs as root file system - skipping.\n");
  53                 return 0;
  54         }
  55
  56         // Create a file
  57         unlink(TEST_FILE);
  58         int fd = open_dprotected_np(TEST_FILE,
  59                                                                 O_RDWR | O_CREAT, 3, 0, 0666);
  60
  61         assert_with_errno(fd >= 0);
  62
  63         struct attrlist attrlist = {
  64                 .bitmapcount = ATTR_BIT_MAP_COUNT,
  65                 .commonattr = ATTR_CMN_DATA_PROTECT_FLAGS,
  66         };
  67
  68         struct attrs {
  69                 uint32_t len;
  70                 uint32_t dp_flags;
  71         } attrs;
  72
  73         assert_no_err(fgetattrlist(fd, &attrlist, &attrs, sizeof(attrs), 0));
  74
  75         // The generation should not be returned here
  76         assert(attrs.dp_flags == 3);
  77
  78         // Check Foundation's API
  79         NSFileManager *fm = [NSFileManager defaultManager];
  80
  81         assert([[fm attributesOfItemAtPath:@TEST_FILE error:NULL][NSFileProtectionKey]
  82                         isEqualToString:NSFileProtectionCompleteUntilFirstUserAuthentication]);
  83
  84         // Change to class A
  85         assert([fm setAttributes:@{ NSFileProtectionKey: NSFileProtectionComplete }
  86                                 ofItemAtPath:@TEST_FILE
  87                                            error:NULL]);
  88
  89         assert([[fm attributesOfItemAtPath:@TEST_FILE error:NULL][NSFileProtectionKey]
  90                         isEqualToString:NSFileProtectionComplete]);
  91
  92         uint32_t keybag_state;
  93         assert(!MKBKeyBagGetSystemGeneration(&keybag_state));
  94
  95         // Class roll
  96         int ret = MKBKeyBagChangeSystemGeneration(NULL, 1);
  97
  98         if (ret && ret != kMobileKeyBagNotReady)
  99                 assert_fail("MKBKeyBagChangeSystemGeneration returned %d\n", ret);
 100
 101         assert(!MKBKeyBagGetSystemGeneration(&keybag_state)
 102                    && (keybag_state & generation_change_in_progress));
 103
 104         static const uint32_t max_ids = 1000000;
 105         static const uint32_t max_ids_per_iter = 262144;
 106
 107         struct listxattrid_cp list_file_ids = {
 108                 .flags = (LSXCP_PROT_CLASS_A | LSXCP_PROT_CLASS_B | LSXCP_PROT_CLASS_C),
 109         };
 110
 111         uint32_t *file_ids = malloc(4 * max_ids);
 112         uint32_t count = 0;
 113
 114         bzero(file_ids, 4 * max_ids);
 115
 116         do {
 117                 list_file_ids.count = max_ids_per_iter;
 118                 list_file_ids.fileid = file_ids + count;
 119
 120                 if (fsctl("/private/var", HFSIOC_LISTXATTRID_CP, &list_file_ids, 0) < 0) {
 121                         assert_with_errno(errno == EINTR);
 122                         count = 0;
 123                         bzero(list_file_ids.state, sizeof(list_file_ids.state));
 124                         continue;
 125                 }
 126                 count += list_file_ids.count;
 127
 128                 assert(count < max_ids);
 129         } while (list_file_ids.count == max_ids_per_iter);
 130
 131         assert_no_err(statfs("/private/var", &sfs));
 132
 133         for (unsigned i = 0; i < count; ++i) {
 134                 char path[PATH_MAX];
 135
 136                 if (fsgetpath(path, sizeof(path), &sfs.f_fsid,
 137                                           (uint64_t)file_ids[i]) < 0) {
 138                         assert_with_errno(errno == ENOENT);
 139                         continue;
 140                 }
 141
 142                 if (fsctl("/private/var", HFSIOC_OP_CPFORCEREWRAP,
 143                                   &file_ids[i], 0) != 0) {
 144                         assert_with_errno(errno == ENOENT);
 145                 }
 146         }
 147
 148         // Mark as done
 149         uint32_t flags = HFS_SET_CPFLAG;
 150
 151         fsctl("/private/var", HFSIOC_OP_CRYPTOGEN, &flags, 0);
 152
 153         int attempts = 0;
 154         while (!_SecKeychainRollKeys(true, NULL) && ++attempts < 1000)
 155                 ;
 156         assert(attempts < 1000);
 157
 158         // Tell MobileKeyBag that we're done
 159         assert(!MKBKeyBagChangeSystemGeneration(NULL, 2));
 160
 161         // Check class again
 162         assert_no_err(fgetattrlist(fd, &attrlist, &attrs, sizeof(attrs), 0));
 163
 164         // The class should still be A
 165         assert(attrs.dp_flags == 1);
 166
 167         // Check Foundation's API
 168         assert([[fm attributesOfItemAtPath:@TEST_FILE error:NULL][NSFileProtectionKey]
 169                         isEqualToString:NSFileProtectionComplete]);
 170
 171         // Change to class C
 172         assert([fm setAttributes:@{ NSFileProtectionKey: NSFileProtectionCompleteUntilFirstUserAuthentication }
 173                                 ofItemAtPath:@TEST_FILE
 174                                            error:NULL]);
 175
 176         assert([[fm attributesOfItemAtPath:@TEST_FILE error:NULL][NSFileProtectionKey]
 177                         isEqualToString:NSFileProtectionCompleteUntilFirstUserAuthentication]);
 178
 179         assert_no_err(close(fd));
 180         assert_no_err(unlink(TEST_FILE));
 181
 182         // Create a new file
 183         fd = open_dprotected_np(TEST_FILE,
 184                                                         O_RDWR | O_CREAT, 3, 0, 0666);
 185
 186         assert_with_errno(fd >= 0);
 187
 188         assert_no_err(fgetattrlist(fd, &attrlist, &attrs, sizeof(attrs), 0));
 189
 190         // Check the class
 191         assert(attrs.dp_flags == 3);
 192
 193         // Check Foundation's API
 194         assert([[fm attributesOfItemAtPath:@TEST_FILE error:NULL][NSFileProtectionKey]
 195                         isEqualToString:NSFileProtectionCompleteUntilFirstUserAuthentication]);
 196
 197         // Change to class A
 198         assert([fm setAttributes:@{ NSFileProtectionKey: NSFileProtectionComplete }
 199                                 ofItemAtPath:@TEST_FILE
 200                                            error:NULL]);
 201
 202         assert([[fm attributesOfItemAtPath:@TEST_FILE error:NULL][NSFileProtectionKey]
 203                         isEqualToString:NSFileProtectionComplete]);
 204
 205         assert_no_err(unlink(TEST_FILE));
 206
 207         printf("[PASSED] getattrlist-dprotect\n");
 208
 209         return 0;
 210 }
 211
 212 #endif // (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR)