libsecurity_transform/lib/Digest_block.c

   1 /*
   2  *  Digest_block.cpp
   3  *  libsecurity_transform
   4  *
   5  *  Created by JOsborne on 2/20/10.
   6  *  Copyright 2010 Apple. All rights reserved.
   7  *
   8  */
   9
  10 #include "Digest_block.h"
  11 #include "SecCustomTransform.h"
  12 #include <CommonCrypto/CommonDigest.h>
  13 #include "Utilities.h"
  14
  15 extern const CFStringRef kSecDigestMD2, kSecDigestMD4, kSecDigestMD5, kSecDigestSHA1, kSecDigestSHA2;
  16 extern const CFStringRef kSecDigestTypeAttribute, kSecDigestLengthAttribute;
  17
  18
  19 static CFStringRef kCustomDigestTransformName = CFSTR("com.apple.security.digest");
  20
  21 SecTransformRef SecDigestTransformCreate_block(SecProviderRef device, CFTypeRef digestType, CFIndex digestLength, CFErrorRef* error) {
  22         static dispatch_once_t inited;
  23         __block CFStringRef current_algo;
  24         __block CFIndex current_length;
  25
  26         dispatch_once(&inited, ^{
  27                 SecTransformRegister(kCustomDigestTransformName, ^(CFStringRef name, SecTransformRebindActionBlock rebind) {
  28                         rebind(kSecTransformActionProcessData, NULL, ^(SecTransformRef tr, CFDataRef d, SecTransformSendAttribute set) {
  29                                 set(kSecDigestTypeAttribute, kSecDigestSHA2);
  30                         });
  31                         rebind(SecTransformSetAttributeAction, NULL, ^(SecTransformRef tr, CFStringRef name, CFTypeRef value, SecTransformSendAttribute set) {
  32                                 Boolean algo_changed = FALSE;
  33                                 if (name == kSecDigestTypeAttribute || CFStringCompare(kSecDigestTypeAttribute, name, 0) == kCFCompareEqualTo) {
  34                                         algo_changed = TRUE;
  35                                         current_algo = CFStringCreateCopy(NULL, (CFStringRef)value);
  36
  37                                 } else if (name == kSecDigestLengthAttribute || CFStringCompare(kSecDigestLengthAttribute, name, 0) == kCFCompareEqualTo) {
  38                                         algo_changed = TRUE;
  39                                         CFNumberGetValue(value, kCFNumberCFIndexType, &current_length);
  40                                 } else if (CFStringCompare(kSecTransformInputAttributeName, name, 0) == kCFCompareEqualTo) {
  41                                         return (CFTypeRef)CreateSecTransformErrorRef(kSecTransformErrorInvalidType, "The type %@ is invalid.", name);
  42                                 } else {
  43                                         return (CFTypeRef)CreateSecTransformErrorRef(kSecTransformErrorInvalidType, "The type %@ is invalid.", name);
  44                                 }
  45                                 if (!algo_changed) {
  46                                         return value;
  47                                 }
  48
  49                                 if (current_algo == kSecDigestSHA2 || CFStringCompare(current_algo, kSecDigestSHA2, 0) == kCFCompareEqualTo) {
  50                                         switch (current_length) {
  51                                                 case 0:
  52                                                 case 512: {
  53                                                         __block CC_SHA512_CTX cc_context;
  54                                                         CC_SHA512_Init(&cc_context);
  55                                                         rebind(kSecTransformActionProcessData, NULL, ^(SecTransformRef tr, CFDataRef d, SecTransformSendAttribute set) {
  56                                                                 if (d) {
  57                                                                         CC_SHA512_Update(&cc_context, CFDataGetBytePtr(d), CFDataGetLength(d));
  58                                                                         return SecTransformNoData();
  59                                                                 } else {
  60                                                                         u_int8_t digest_buffer[CC_SHA512_DIGEST_LENGTH];
  61
  62                                                                         CC_SHA512_Final(digest_buffer, &cc_context);
  63                                                                         set(kSecTransformOutputAttributeName, CFDataCreate(NULL, digest_buffer, CC_SHA512_DIGEST_LENGTH));
  64                                                                         return NULL;
  65                                                                 }
  66                                                         });
  67                                                         return value;
  68                                                 }
  69                                         }
  70                                         return (CFTypeRef)CreateSecTransformErrorRef(kSecTransformErrorInvalidLength, "Invalid length.");
  71                                 } else {
  72                                         return (CFTypeRef)CreateSecTransformErrorRef(kSecTransformErrorInvalidAlgorithm, "Invalid algorithm.");
  73                                 }
  74                         });
  75                 }, NULL);
  76         });
  77
  78         SecTransformRef dt = SecTransformCreate(kCustomDigestTransformName, NULL);
  79         SecTransformSetAttribute(dt, kSecDigestTypeAttribute, digestType, error);
  80         CFNumberRef dlen = CFNumberCreate(NULL, kCFNumberCFIndexType, &digestLength);
  81         SecTransformSetAttribute(dt, kSecDigestLengthAttribute, dlen, error);
  82         CFRelease(dlen);
  83
  84         return dt;
  85 }