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
19const 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
45size_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
57uint8_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}
79