utilities/src/SecCFCanonicalHashes.c

   1 //
   2 //  SecCFCanonicalHashes.c
   3 //  utilities
   4 //
   5 //  Created by Mitch Adler on 2/8/12.
   6 //  Copyright (c) 2012 Apple Inc. All rights reserved.
   7 //
   8
   9 #include <stdio.h>
  10
  11 #include "utilities/SecCFCanonicalHashes.h"
  12 #include "utilities/comparison.h"
  13
  14 #include <CoreFoundation/CFArray.h>
  15 #include <CoreFoundation/CFString.h>
  16 #include <CoreFoundation/CFData.h>
  17 #include <utilities/SecCFRelease.h>
  18 #include <corecrypto/ccdigest.h>
  19
  20 struct AddKeyValueHashContext {
  21     CFMutableArrayRef array;
  22     const struct ccdigest_info* di;
  23     bool fail;
  24 };
  25
  26 static void AddKeyValueHashData(const void *key, const void *value, void *context)
  27 {
  28     struct AddKeyValueHashContext* akvContext = (struct AddKeyValueHashContext*) context;
  29
  30     size_t key_len;
  31     const void* key_data;
  32     if (CFGetTypeID(key) == CFStringGetTypeID()) {
  33         key_len = CFStringGetLength((CFStringRef) key);
  34         key_data = CFStringGetCharactersPtr((CFStringRef) key);
  35     } else {
  36         akvContext->fail = true;
  37         return;
  38     }
  39
  40     size_t value_len;
  41     const void* value_data;
  42     if (CFGetTypeID(key) == CFStringGetTypeID()) {
  43         value_len = CFStringGetLength((CFStringRef) value);
  44         value_data = CFStringGetCharactersPtr((CFStringRef) value);
  45     } else if (CFGetTypeID(key) == CFDataGetTypeID()) {
  46         value_len = CFDataGetLength((CFDataRef)value);
  47         value_data = CFDataGetBytePtr((CFDataRef)value);
  48     } else {
  49         akvContext->fail = true;
  50         return;
  51     }
  52
  53     UInt8 hashBuffer[akvContext->di->output_size];
  54
  55     ccdigest_di_decl(akvContext->di, finalContext);
  56
  57     ccdigest(akvContext->di, key_len, key_data, hashBuffer);
  58
  59     ccdigest_init(akvContext->di, finalContext);
  60     ccdigest_update(akvContext->di, finalContext, sizeof(hashBuffer), hashBuffer);
  61
  62     ccdigest_update(akvContext->di, finalContext, sizeof(hashBuffer), hashBuffer);
  63     ccdigest(akvContext->di, value_len, value_data, hashBuffer);
  64
  65     ccdigest_final(akvContext->di, finalContext, (void*)hashBuffer);
  66
  67     CFDataRef hash = CFDataCreate(kCFAllocatorDefault, hashBuffer, sizeof(hashBuffer));
  68     CFArrayAppendValue(akvContext->array, hash);
  69     CFReleaseSafe(hash);
  70 }
  71
  72 static CFComparisonResult CFDataCompare(CFDataRef d1, CFDataRef d2)
  73 {
  74     CFIndex d1_size = CFDataGetLength(d1);
  75     CFIndex d2_size = CFDataGetLength(d2);
  76
  77     CFIndex comparison = memcmp(CFDataGetBytePtr(d1), CFDataGetBytePtr(d2), MIN(d1_size, d2_size));
  78
  79     if (comparison == 0)
  80         comparison = d1_size - d2_size;
  81
  82     return (comparison > 0) ? kCFCompareGreaterThan : ((comparison < 0) ? kCFCompareLessThan : kCFCompareEqualTo);
  83 }
  84
  85 static CFComparisonResult CFEqualComparitor(const void *val1, const void *val2, void * context __unused)
  86 {
  87     return CFDataCompare((CFDataRef) val1, (CFDataRef) val2);
  88 }
  89
  90 struct array_hashing_context {
  91     const struct ccdigest_info* di;
  92     struct ccdigest_ctx *       ctx;
  93 };
  94
  95 static void hash_CFDatas(const void *value, void *context)
  96 {
  97     struct array_hashing_context* ahc = (struct array_hashing_context*) context;
  98
  99     ccdigest_update(ahc->di, ahc->ctx, CFDataGetLength((CFDataRef) value), CFDataGetBytePtr((CFDataRef) value));
 100 }
 101
 102
 103 bool SecCFAppendCFDictionaryHash(CFDictionaryRef thisDictionary, const struct ccdigest_info* di, CFMutableDataRef toThis)
 104 {
 105     CFMutableArrayRef hashArray = CFArrayCreateMutable(kCFAllocatorDefault, CFDictionaryGetCount(thisDictionary), &kCFTypeArrayCallBacks);
 106
 107     CFDictionaryApplyFunction(thisDictionary, &AddKeyValueHashData, hashArray);
 108
 109     CFRange wholeArray = CFRangeMake(0, CFArrayGetCount(hashArray));
 110
 111     CFArraySortValues(hashArray, wholeArray, &CFEqualComparitor, NULL);
 112
 113     ccdigest_di_decl(di, finalContext);
 114
 115     struct array_hashing_context ahc = { .di = di, .ctx = (struct ccdigest_ctx*)&finalContext};
 116
 117     CFArrayApplyFunction(hashArray, wholeArray, hash_CFDatas, &ahc);
 118
 119     return true;
 120 }