SecurityTool/sharedTool/keychain_util.c

   1 /*
   2  * Copyright (c) 2014 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 #include <stdio.h>
  26 #include <AssertMacros.h>
  27 #include <utilities/SecCFWrappers.h>
  28 #include <ACMDefs.h>
  29 #include <ACMAclDefs.h>
  30 #include <libaks_acl_cf_keys.h>
  31
  32 #include "security.h"
  33 #include "keychain_util.h"
  34 #include <Security/SecAccessControlPriv.h>
  35
  36 static CFStringRef createStringForValue(CFTypeRef value)
  37 {
  38     CFStringRef result = NULL;
  39     if (CFDataGetTypeID() == CFGetTypeID(value)) {
  40         CFMutableStringRef stringData = CFStringCreateMutable(kCFAllocatorDefault, 0);
  41         CFStringAppend(stringData, CFSTR("<"));
  42         const UInt8 *dataPtr = CFDataGetBytePtr(value);
  43         for (int i = 0; i < CFDataGetLength(value); ++i) {
  44             CFStringAppendFormat(stringData, NULL, CFSTR("%02x"), dataPtr[i]);
  45         }
  46         CFStringAppend(stringData, CFSTR(">"));
  47         result = stringData;
  48     } else if (CFBooleanGetTypeID() == CFGetTypeID(value)) {
  49         if (CFEqual(value, kCFBooleanTrue))
  50             result = CFStringCreateWithCString(kCFAllocatorDefault, "true", kCFStringEncodingUTF8);
  51         else
  52             result = CFStringCreateWithCString(kCFAllocatorDefault, "false", kCFStringEncodingUTF8);
  53     } else if (CFNumberGetTypeID() == CFGetTypeID(value))
  54         result = CFStringCreateWithFormat(kCFAllocatorDefault, NULL, CFSTR("%@"), value);
  55     else if (CFStringGetTypeID() == CFGetTypeID(value))
  56         result = CFStringCreateCopy(kCFAllocatorDefault, value);
  57     else
  58         result = CFStringCreateWithCString(kCFAllocatorDefault, "unrecognized value", kCFStringEncodingUTF8);
  59
  60     return result;
  61 }
  62
  63 static CFStringRef createStringForKofn(CFDictionaryRef kofn)
  64 {
  65     CFMutableStringRef result = NULL;
  66     if (kofn != NULL && CFDictionaryGetTypeID() == CFGetTypeID(kofn))
  67     {
  68         result = CFStringCreateMutable(kCFAllocatorDefault, 0);
  69         CFDictionaryForEach(kofn, ^(const void *key, const void *value) {
  70
  71             CFStringAppend(result, key);
  72             CFStringAppend(result, CFSTR("("));
  73
  74             CFStringRef valueString = createStringForKofn(value) ?: createStringForValue(value);
  75             CFStringAppend(result, valueString);
  76             CFStringAppend(result, CFSTR(")"));
  77             CFReleaseSafe(valueString);
  78         });
  79     }
  80
  81     return result;
  82 }
  83
  84 static CFStringRef createStringForOps(CFDictionaryRef constraints)
  85 {
  86     CFMutableStringRef result = NULL;
  87     if (constraints != NULL)
  88     {
  89         result = CFStringCreateMutable(kCFAllocatorDefault, 0);
  90         CFDictionaryForEach(constraints, ^(const void *key, const void *value) {
  91             if (CFStringGetLength(result) > 0)
  92                 CFStringAppend(result, CFSTR(";"));
  93             CFStringAppend(result, key);
  94             CFStringAppend(result, CFSTR("("));
  95             CFStringRef valueString = createStringForKofn(value) ?: createStringForValue(value);
  96             CFStringAppend(result, valueString);
  97             CFStringAppend(result, CFSTR(")"));
  98             CFReleaseSafe(valueString);
  99         });
 100     }
 101
 102     return result;
 103 }
 104
 105 void
 106 display_sac_line(SecAccessControlRef sac, CFMutableStringRef line)
 107 {
 108     CFTypeRef protection = SecAccessControlGetProtection(sac);
 109     if (CFDictionaryGetTypeID() == CFGetTypeID(protection)) {
 110         CFStringRef protectionStr = createStringForOps(protection);
 111         CFStringAppend(line, protectionStr);
 112         CFRelease(protectionStr);
 113     } else if (CFStringGetTypeID() == CFGetTypeID(protection))
 114         CFStringAppend(line, protection);
 115     else
 116         CFStringAppend(line, CFSTR("??"));
 117
 118     CFDictionaryRef constraints = SecAccessControlGetConstraints(sac);
 119     CFStringRef constraintsString = createStringForOps(constraints);
 120     if (constraintsString) {
 121         CFStringAppend(line, CFSTR(";"));
 122         CFStringAppend(line, constraintsString);
 123     }
 124     CFReleaseSafe(constraintsString);
 125 }
 126
 127 bool
 128 keychain_query_parse_cstring(CFMutableDictionaryRef q, const char *query) {
 129     CFStringRef s;
 130     s = CFStringCreateWithCStringNoCopy(0, query, kCFStringEncodingUTF8, kCFAllocatorNull);
 131     bool result = keychain_query_parse_string(q, s);
 132     CFRelease(s);
 133     return result;
 134 }
 135
 136 /* Parse a string of the form attr=value,attr=value,attr=value */
 137 bool
 138 keychain_query_parse_string(CFMutableDictionaryRef q, CFStringRef s) {
 139     bool inkey = true;
 140     bool escaped = false;
 141     bool error = false;
 142     CFStringRef key = NULL;
 143     CFMutableStringRef str = CFStringCreateMutable(0, 0);
 144     CFRange rng = { .location = 0, .length = CFStringGetLength(s) };
 145     CFCharacterSetRef cs_key = CFCharacterSetCreateWithCharactersInString(0, CFSTR("=\\"));
 146     CFCharacterSetRef cs_value = CFCharacterSetCreateWithCharactersInString(0, CFSTR(",\\"));
 147     while (rng.length) {
 148         CFRange r;
 149         CFStringRef sub;
 150         bool complete = false;
 151         if (escaped) {
 152             r.location = rng.location;
 153             r.length = 1;
 154             sub = CFStringCreateWithSubstring(0, s, r);
 155             escaped = false;
 156         } else if (CFStringFindCharacterFromSet(s, inkey ? cs_key : cs_value, rng, 0, &r)) {
 157             if (CFStringGetCharacterAtIndex(s, r.location) == '\\') {
 158                 escaped = true;
 159             } else {
 160                 complete = true;
 161             }
 162             CFIndex next = r.location + 1;
 163             r.length = r.location - rng.location;
 164             r.location = rng.location;
 165             sub = CFStringCreateWithSubstring(0, s, r);
 166             rng.length -= next - rng.location;
 167             rng.location = next;
 168         } else {
 169             sub = CFStringCreateWithSubstring(0, s, rng);
 170             rng.location += rng.length;
 171             rng.length = 0;
 172             complete = true;
 173         }
 174         CFStringAppend(str, sub);
 175         CFRelease(sub);
 176
 177         if (complete) {
 178             CFStringRef value = CFStringCreateCopy(0, str);
 179             CFStringReplaceAll(str, CFSTR(""));
 180             if (inkey) {
 181                 key = value;
 182             } else {
 183                 if(key && CFStringCompare(key, kSecAttrAccessControl, kCFCompareCaseInsensitive) == kCFCompareEqualTo) {
 184                     SecAccessControlRef sac = keychain_query_parse_sac(value);
 185                     if(sac) {
 186                         CFDictionarySetValue(q, key, sac);
 187                     } else {
 188                         fprintf(stderr, "failed to parse access control\n");
 189                         error = true;
 190                     }
 191                 } else {
 192                     CFDictionarySetValue(q, key, value);
 193                 }
 194                 CFReleaseNull(value);
 195                 CFReleaseNull(key);
 196             }
 197             inkey = !inkey;
 198         }
 199         if(error)
 200             break;
 201     }
 202     if (key) {
 203         /* Dangeling key value is true?. */
 204         CFDictionarySetValue(q, key, kCFBooleanTrue);
 205         CFReleaseNull(key);
 206     }
 207     CFRelease(str);
 208     CFRelease(cs_key);
 209     CFRelease(cs_value);
 210     return error == false;
 211 }
 212
 213 static uint32_t findLeft(CFStringRef s, uint32_t off)
 214 {
 215     for (int i = off; i < CFStringGetLength(s); ++i) {
 216         if (CFStringGetCharacterAtIndex(s, i) == '(')
 217             return i;
 218     }
 219
 220     return 0;
 221 }
 222
 223 static uint32_t findRight(CFStringRef s, uint32_t off)
 224 {
 225     int bracersCount = 0;
 226     for (int i = off; i < CFStringGetLength(s); ++i) {
 227         if (CFStringGetCharacterAtIndex(s, i) == '(')
 228             ++bracersCount;
 229
 230         if (CFStringGetCharacterAtIndex(s, i) == ')') {
 231             --bracersCount;
 232             if (bracersCount == 0) {
 233                 return i;
 234             }
 235         }
 236     }
 237
 238     return 0;
 239 }
 240
 241 static bool parseKeyAndValue(CFStringRef string, CFTypeRef *key, CFTypeRef *value);
 242
 243 CF_RETURNS_RETAINED
 244 static CFTypeRef parseValue(CFStringRef string)
 245 {
 246     CFTypeRef result = NULL, key = NULL, value = NULL;
 247     CFMutableDictionaryRef resultDictionary = NULL;
 248     CFStringRef subString = NULL;
 249
 250     uint32_t left = findLeft(string, 0);
 251     if (left > 0) {
 252         uint32_t offset = 0;
 253         resultDictionary = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
 254         for (;;) {
 255             uint32_t right = findRight(string, left);
 256             if (!right)
 257                 break;
 258             CFAssignRetained(subString, CFStringCreateWithSubstring(kCFAllocatorDefault, string, CFRangeMake(offset, (right + 1) - offset)));
 259             require_quiet(parseKeyAndValue(subString, &key, &value), out);
 260             CFDictionarySetValue(resultDictionary, key, value);
 261             offset = right + 1;
 262             left = findLeft(string, offset);
 263             if (!left)
 264                 break;
 265         }
 266         result = CFRetain(resultDictionary);
 267     } else if (CFStringGetCharacterAtIndex(string, 0) == '<' && CFStringGetCharacterAtIndex(string, CFStringGetLength(string) - 1) == '>') {
 268         CFMutableDataRef data = CFDataCreateMutable(kCFAllocatorDefault, 0);
 269         if (CFStringGetLength(string) > 2) {
 270             CFAssignRetained(subString, CFStringCreateWithSubstring(kCFAllocatorDefault, string, CFRangeMake(1, CFStringGetLength(string) - 2)));
 271             const char *asciiString = CFStringGetCStringPtr(subString, kCFStringEncodingASCII);
 272             uint8_t byte;
 273             for(uint32_t i = 0; i < strlen(asciiString); i += 2) {
 274                 sscanf(&asciiString[i], "%02hhx", &byte);
 275                 CFDataAppendBytes(data, &byte, sizeof(byte));
 276             }
 277         }
 278         result = data;
 279     } else if (CFStringCompare(string, CFSTR("true"), 0) == kCFCompareEqualTo) {
 280         CFRetainAssign(result, kCFBooleanTrue);
 281     } else if (CFStringCompare(string, CFSTR("false"), 0) == kCFCompareEqualTo) {
 282         CFRetainAssign(result, kCFBooleanFalse);
 283     } else if (CFStringCompare(string, CFSTR(kACMPolicyDeviceOwnerAuthentication), 0) == kCFCompareEqualTo) {
 284         CFRetainAssign(result, CFSTR(kACMPolicyDeviceOwnerAuthentication));
 285     } else {
 286         CFLocaleRef currentLocale = CFLocaleCopyCurrent();
 287         CFNumberFormatterRef formaterRef = CFNumberFormatterCreate(kCFAllocatorDefault, currentLocale, kCFNumberFormatterDecimalStyle);
 288         result = CFNumberFormatterCreateNumberFromString(kCFAllocatorDefault, formaterRef, string, NULL, kCFNumberFormatterParseIntegersOnly);
 289         CFReleaseSafe(currentLocale);
 290         CFReleaseSafe(formaterRef);
 291     }
 292
 293     if (!result)
 294         fprintf(stderr, "Failed to parse value: %s\n", CFStringGetCStringPtr(string, kCFStringEncodingUTF8));
 295
 296 out:
 297     CFReleaseSafe(key);
 298     CFReleaseSafe(value);
 299     CFReleaseSafe(subString);
 300     CFReleaseSafe(resultDictionary);
 301
 302     return result;
 303 }
 304
 305 static bool parseKeyAndValue(CFStringRef string, CFTypeRef *key, CFTypeRef *value)
 306 {
 307     bool ok = false;
 308     CFStringRef keyString = NULL;
 309     CFStringRef valueString = NULL;
 310     CFTypeRef parsedValue = NULL;
 311
 312     uint32_t left = findLeft(string, 0);
 313     require_action_quiet(left != 0, out, fprintf(stderr, "Failed to find '(' in: %s\n", CFStringGetCStringPtr(string, kCFStringEncodingUTF8)));
 314     uint32_t right = findRight(string, left);
 315     require_action_quiet(right != 0, out, fprintf(stderr, "Failed to find ')' in: %s\n", CFStringGetCStringPtr(string, kCFStringEncodingUTF8)));
 316     require_action_quiet(right == ((uint32_t)CFStringGetLength(string) - 1), out, fprintf(stderr, "Failed to find ')' in: %s\n", CFStringGetCStringPtr(string, kCFStringEncodingUTF8)));
 317
 318     keyString  = CFStringCreateWithSubstring(kCFAllocatorDefault, string, CFRangeMake(0, left));
 319     valueString = CFStringCreateWithSubstring(kCFAllocatorDefault, string, CFRangeMake(left + 1, right - left - 1));
 320     require_quiet(parsedValue = parseValue(valueString), out);
 321     CFRetainAssign(*key, keyString);
 322     CFRetainAssign(*value, parsedValue);
 323     ok = true;
 324
 325 out:
 326     CFReleaseSafe(parsedValue);
 327     CFReleaseSafe(keyString);
 328     CFReleaseSafe(valueString);
 329
 330     return ok;
 331 }
 332
 333 SecAccessControlRef
 334 keychain_query_parse_sac(CFStringRef s) {
 335     SecAccessControlRef sac = NULL, result = NULL;
 336     CFTypeRef key = NULL, value = NULL;
 337     CFArrayRef tokens = CFStringCreateArrayBySeparatingStrings(NULL, s, CFSTR(";"));
 338
 339     // process protection part
 340     CFStringRef protection = CFArrayGetValueAtIndex(tokens, 0);
 341
 342     CFErrorRef error = NULL;
 343     require_quiet(sac = SecAccessControlCreate(kCFAllocatorDefault, &error), out);
 344     require_quiet(SecAccessControlSetProtection(sac, protection, &error), out);
 345
 346     CFIndex tokensCnt = CFArrayGetCount(tokens);
 347     for(CFIndex i = 1; i < tokensCnt; ++i) {
 348         require_action_quiet(parseKeyAndValue(CFArrayGetValueAtIndex(tokens, i), &key, &value), out, fprintf(stderr, "Error constructing SecAccessConstraint object\n") );
 349
 350         if (CFEqual(key, CFSTR(kACMKeyAclParamRequirePasscode)))
 351             SecAccessControlSetRequirePassword(sac, CFEqual(value, kCFBooleanTrue)?true:false);
 352         else
 353             SecAccessControlAddConstraintForOperation(sac, key, value, NULL);
 354     }
 355
 356     SecAccessConstraintRef constraintForDelete = SecAccessControlGetConstraint(sac, kAKSKeyOpDelete);
 357     if (!constraintForDelete) {
 358         if(!SecAccessControlAddConstraintForOperation(sac, kAKSKeyOpDelete, kCFBooleanTrue, &error)) {
 359             fprintf(stderr, "adding delete operation to sac object failed \n");
 360         }
 361     }
 362
 363     SecAccessConstraintRef constraintForEncrypt = SecAccessControlGetConstraint(sac, kAKSKeyOpEncrypt);
 364     if (!constraintForEncrypt) {
 365         if(!SecAccessControlAddConstraintForOperation(sac, kAKSKeyOpEncrypt, kCFBooleanTrue, &error)) {
 366             fprintf(stderr, "adding encrypt operation to sac object failed \n");
 367         }
 368     }
 369
 370     CFRetainAssign(result, sac);
 371
 372 out:
 373     CFReleaseSafe(tokens);
 374     CFReleaseSafe(key);
 375     CFReleaseSafe(value);
 376     CFReleaseSafe(sac);
 377
 378     return result;
 379 }