utilities/src/der_string.c

   1 //
   2 //  der_string.c
   3 //  utilities
   4 //
   5 //  Created by Mitch Adler on 6/18/12.
   6 //  Copyright (c) 2012 Apple Inc. All rights reserved.
   7 //
   8
   9 #include <stdio.h>
  10
  11 #include "utilities/SecCFRelease.h"
  12 #include "utilities/der_plist.h"
  13 #include "utilities/der_plist_internal.h"
  14
  15 #include <corecrypto/ccder.h>
  16 #include <CoreFoundation/CoreFoundation.h>
  17
  18
  19 const uint8_t* der_decode_string(CFAllocatorRef allocator, CFOptionFlags mutability,
  20                                  CFStringRef* string, CFErrorRef *error,
  21                                  const uint8_t* der, const uint8_t *der_end)
  22 {
  23     if (NULL == der)
  24         return NULL;
  25
  26     size_t payload_size = 0;
  27     const uint8_t *payload = ccder_decode_tl(CCDER_UTF8_STRING, &payload_size, der, der_end);
  28
  29     if (NULL == payload || (der_end - payload) < payload_size){
  30         SecCFDERCreateError(kSecDERErrorUnknownEncoding, CFSTR("Unknown string encoding"), NULL, error);
  31         return NULL;
  32     }
  33
  34     *string = CFStringCreateWithBytes(allocator, payload, payload_size, kCFStringEncodingUTF8, false);
  35
  36     if (NULL == *string) {
  37         SecCFDERCreateError(kSecDERErrorAllocationFailure, CFSTR("String allocation failed"), NULL, error);
  38         return NULL;
  39     }
  40
  41     return payload + payload_size;
  42 }
  43
  44
  45 size_t der_sizeof_string(CFStringRef str, CFErrorRef *error)
  46 {
  47     const CFIndex str_length    = CFStringGetLength(str);
  48     const CFIndex maximum       = CFStringGetMaximumSizeForEncoding(str_length, kCFStringEncodingUTF8);
  49
  50     CFIndex encodedLen = 0;
  51     CFIndex converted = CFStringGetBytes(str, CFRangeMake(0, str_length), kCFStringEncodingUTF8, 0, false, NULL, maximum, &encodedLen);
  52
  53     return ccder_sizeof(CCDER_UTF8_STRING, (converted == str_length) ? encodedLen : 0);
  54 }
  55
  56
  57 uint8_t* der_encode_string(CFStringRef string, CFErrorRef *error,
  58                            const uint8_t *der, uint8_t *der_end)
  59 {
  60     // Obey the NULL allowed rules.
  61     if (!der_end)
  62         return NULL;
  63
  64     const CFIndex str_length = CFStringGetLength(string);
  65
  66     ptrdiff_t der_space = der_end - der;
  67     CFIndex bytes_used = 0;
  68     uint8_t *buffer = der_end - der_space;
  69     CFIndex converted = CFStringGetBytes(string, CFRangeMake(0, str_length), kCFStringEncodingUTF8, 0, false, buffer, der_space, &bytes_used);
  70     if (converted != str_length){
  71         SecCFDERCreateError(kSecDERErrorUnderlyingError, CFSTR("String extraction failed"), NULL, error);
  72         return NULL;
  73     }
  74
  75     return ccder_encode_tl(CCDER_UTF8_STRING, bytes_used, der,
  76            ccder_encode_body(bytes_used, buffer, der, der_end));
  77
  78 }