Security/authd/credential.c

   1 /* Copyright (c) 2012-2013 Apple Inc. All Rights Reserved. */
   2
   3 #include "credential.h"
   4 #include "authutilities.h"
   5 #include "debugging.h"
   6 #include "crc.h"
   7
   8 #include <pwd.h>
   9 #include <membership.h>
  10 #include <membershipPriv.h>
  11
  12 struct _credential_s {
  13     __AUTH_BASE_STRUCT_HEADER__;
  14
  15     bool right;   // is least-privileged credential
  16
  17     uid_t uid;
  18     char * name;
  19     char * realName;
  20
  21     CFAbsoluteTime creationTime;
  22     bool valid;
  23     bool shared;
  24
  25     CFMutableSetRef cachedGroups;
  26 };
  27
  28 static void
  29 _credential_finalize(CFTypeRef value)
  30 {
  31     credential_t cred = (credential_t)value;
  32
  33     free_safe(cred->name);
  34     free_safe(cred->realName);
  35     CFReleaseSafe(cred->cachedGroups);
  36 }
  37
  38 static CFStringRef
  39 _credential_copy_description(CFTypeRef value)
  40 {
  41     credential_t cred = (credential_t)value;
  42     CFStringRef str = NULL;
  43     CFTimeZoneRef sys_tz = CFTimeZoneCopySystem();
  44     CFGregorianDate date = CFAbsoluteTimeGetGregorianDate(cred->creationTime, sys_tz);
  45     CFReleaseSafe(sys_tz);
  46     if (cred->right) {
  47         str = CFStringCreateWithFormat(kCFAllocatorDefault, NULL, CFSTR("credential: right=%s, shared=%i, creation=%01i:%01i:%01i, valid=%i"), cred->name, cred->shared, date.hour,date.minute,(int32_t)date.second, cred->valid);
  48     } else {
  49         str = CFStringCreateWithFormat(kCFAllocatorDefault, NULL, CFSTR("credential: uid=%i, name=%s, shared=%i, creation=%01i:%01i:%01i valid=%i"), cred->uid, cred->name, cred->shared, date.hour,date.minute,(int32_t)date.second, cred->valid);
  50     }
  51     return str;
  52 }
  53
  54 static CFHashCode
  55 _credential_hash(CFTypeRef value)
  56 {
  57     credential_t cred = (credential_t)value;
  58     uint64_t crc = crc64_init();
  59     if (cred->right) {
  60         crc = crc64_update(crc, cred->name, strlen(cred->name));
  61     } else {
  62         crc = crc64_update(crc, &cred->uid, sizeof(cred->uid));
  63     }
  64     crc = crc64_update(crc, &cred->shared, sizeof(cred->shared));
  65     crc = crc64_final(crc);
  66
  67     return crc;
  68 }
  69
  70 static Boolean
  71 _credential_equal(CFTypeRef value1, CFTypeRef value2)
  72 {
  73     credential_t cred1 = (credential_t)value1;
  74     credential_t cred2 = (credential_t)value2;
  75
  76     return _credential_hash(cred1) == _credential_hash(cred2);
  77 }
  78
  79 AUTH_TYPE_INSTANCE(credential,
  80                    .init = NULL,
  81                    .copy = NULL,
  82                    .finalize = _credential_finalize,
  83                    .equal = _credential_equal,
  84                    .hash = _credential_hash,
  85                    .copyFormattingDesc = NULL,
  86                    .copyDebugDesc = _credential_copy_description
  87                    );
  88
  89 static CFTypeID credential_get_type_id() {
  90     static CFTypeID type_id = _kCFRuntimeNotATypeID;
  91     static dispatch_once_t onceToken;
  92
  93     dispatch_once(&onceToken, ^{
  94         type_id = _CFRuntimeRegisterClass(&_auth_type_credential);
  95     });
  96
  97     return type_id;
  98 }
  99
 100 static credential_t
 101 _credential_create()
 102 {
 103     credential_t cred = NULL;
 104
 105     cred = (credential_t)_CFRuntimeCreateInstance(kCFAllocatorDefault, credential_get_type_id(), AUTH_CLASS_SIZE(credential), NULL);
 106     require(cred != NULL, done);
 107
 108     cred->creationTime = CFAbsoluteTimeGetCurrent();
 109     cred->cachedGroups = CFSetCreateMutable(kCFAllocatorDefault, 0, &kCFTypeSetCallBacks);;
 110
 111 done:
 112     return cred;
 113 }
 114
 115 credential_t
 116 credential_create(uid_t uid)
 117 {
 118     credential_t cred = NULL;
 119
 120     cred = _credential_create();
 121     require(cred != NULL, done);
 122
 123     struct passwd *pw = getpwuid(uid);
 124         if (pw != NULL) {
 125         // avoid hinting a locked account
 126                 if ( (pw->pw_passwd == NULL) || strcmp(pw->pw_passwd, "*") ) {
 127             cred->uid = pw->pw_uid;
 128             cred->name = _copy_string(pw->pw_name);
 129             cred->realName = _copy_string(pw->pw_gecos);
 130             cred->valid = true;
 131         } else {
 132             cred->uid = (uid_t)-2;
 133             cred->valid = false;
 134         }
 135         endpwent();
 136     }
 137
 138 done:
 139     return cred;
 140 }
 141
 142 credential_t
 143 credential_create_with_credential(credential_t srcCred, bool shared)
 144 {
 145     credential_t cred = NULL;
 146
 147     cred = _credential_create();
 148     require(cred != NULL, done);
 149
 150     cred->uid = srcCred->uid;
 151     cred->name = _copy_string(srcCred->name);
 152     cred->realName = _copy_string(srcCred->realName);
 153     cred->valid = srcCred->valid;
 154     cred->right = srcCred->right;
 155     cred->shared = shared;
 156
 157 done:
 158     return cred;
 159 }
 160
 161 credential_t
 162 credential_create_with_right(const char * right)
 163 {
 164     credential_t cred = NULL;
 165
 166     cred = _credential_create();
 167     require(cred != NULL, done);
 168
 169     cred->right = true;
 170     cred->name = _copy_string(right);
 171     cred->uid = (uid_t)-2;
 172     cred->valid = true;
 173
 174 done:
 175     return cred;
 176 }
 177
 178 uid_t
 179 credential_get_uid(credential_t cred)
 180 {
 181     return cred->uid;
 182 }
 183
 184 const char *
 185 credential_get_name(credential_t cred)
 186 {
 187     return cred->name;
 188 }
 189
 190 const char *
 191 credential_get_realname(credential_t cred)
 192 {
 193     return cred->realName;
 194 }
 195
 196 CFAbsoluteTime
 197 credential_get_creation_time(credential_t cred)
 198 {
 199     return cred->creationTime;
 200 }
 201
 202 bool
 203 credential_get_valid(credential_t cred)
 204 {
 205     return cred->valid;
 206 }
 207
 208 bool
 209 credential_get_shared(credential_t cred)
 210 {
 211     return cred->shared;
 212 }
 213
 214 bool
 215 credential_is_right(credential_t cred)
 216 {
 217     return cred->right;
 218 }
 219
 220 bool
 221 credential_check_membership(credential_t cred,const char* group)
 222 {
 223     bool result = false;
 224     CFStringRef cachedGroup = NULL;
 225     require(group != NULL, done);
 226     require(cred->uid != 0 || cred->uid != (uid_t)-2, done);
 227     require(cred->right != true, done);
 228
 229     cachedGroup = CFStringCreateWithCString(kCFAllocatorDefault, group, kCFStringEncodingUTF8);
 230     require(cachedGroup != NULL, done);
 231
 232     if (CFSetGetValue(cred->cachedGroups, cachedGroup) != NULL) {
 233         result = true;
 234         goto done;
 235     }
 236
 237     int rc, ismember;
 238     uuid_t group_uuid, user_uuid;
 239     rc = mbr_group_name_to_uuid(group, group_uuid);
 240     require_noerr(rc, done);
 241
 242     rc = mbr_uid_to_uuid(cred->uid, user_uuid);
 243     require_noerr(rc, done);
 244
 245     rc = mbr_check_membership(user_uuid, group_uuid, &ismember);
 246     require_noerr(rc, done);
 247
 248     result = ismember;
 249
 250     if (ismember) {
 251         CFSetSetValue(cred->cachedGroups, cachedGroup);
 252     }
 253
 254 done:
 255     CFReleaseSafe(cachedGroup);
 256     return result;
 257 }
 258
 259 void
 260 credential_invalidate(credential_t cred)
 261 {
 262     cred->valid = false;
 263 }