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1 /*
2 * Copyright (c) 2012 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 <CoreFoundation/CoreFoundation.h>
26 #include "corecrypto/ccsha1.h"
27 #include "corecrypto/ccrsa_priv.h"
28 #include "corecrypto/ccrng_system.h"
29 #include "corecrypto/ccn.h"
30 #include "stdio.h"
31 #include "misc.h"
32 #include "Utilities.h"
33
34 // corecrypto headers don't like C++ (on a deaper level then extern "C" {} can fix
35 // so we need a C "shim" for all our corecrypto use.
36
37 CFDataRef oaep_padding_via_c(int desired_message_length, CFDataRef dataValue);
38 CFDataRef oaep_padding_via_c(int desired_message_length, CFDataRef dataValue) CF_RETURNS_RETAINED
39 {
40 cc_unit paddingBuffer[ccn_nof_size(desired_message_length)];
41 bzero(paddingBuffer, sizeof(cc_unit) * ccn_nof_size(desired_message_length)); // XXX needed??
42 static dispatch_once_t randomNumberGenneratorInitialzed;
43 static struct ccrng_system_state rng;
44 dispatch_once(&randomNumberGenneratorInitialzed, ^{
45 ccrng_system_init(&rng);
46 });
47
48 ccrsa_oaep_encode(ccsha1_di(),
49 (struct ccrng_state*)&rng,
50 sizeof(paddingBuffer), (cc_unit*)paddingBuffer,
51 CFDataGetLength(dataValue), CFDataGetBytePtr(dataValue));
52 ccn_swap(ccn_nof_size(sizeof(paddingBuffer)), (cc_unit*)paddingBuffer);
53
54 CFDataRef paddedValue = CFDataCreate(NULL, (UInt8*)paddingBuffer, desired_message_length);
55 return paddedValue ? paddedValue : (void*)GetNoMemoryErrorAndRetain();
56 }
57
58 CFDataRef oaep_unpadding_via_c(CFDataRef encodedMessage);
59 CFDataRef oaep_unpadding_via_c(CFDataRef encodedMessage) CF_RETURNS_RETAINED
60 {
61 size_t mlen = CFDataGetLength(encodedMessage);
62 cc_size n = ccn_nof_size(mlen);
63 cc_unit paddingBuffer[n];
64 UInt8 plainText[mlen];
65
66 ccn_read_uint(n, paddingBuffer, mlen, CFDataGetBytePtr(encodedMessage));
67 size_t plainTextLength = mlen;
68 int err = ccrsa_oaep_decode(ccsha1_di(), &plainTextLength, plainText, mlen, paddingBuffer);
69
70 if (err) {
71 // XXX should make a CFError or something.
72 CFErrorRef error = fancy_error(CFSTR("CoreCrypto"), err, CFSTR("OAEP decode error"));
73 CFRetainSafe(error);
74 return (void*)error;
75 }
76 CFDataRef result = CFDataCreate(NULL, (UInt8*)plainText, plainTextLength);
77 return result;
78 }