FRAOathCode.m revision caa9e77dc369fea8df9ae2c598d3c83b7214c1cf
/*
* The contents of this file are subject to the terms of the Common Development and
* Distribution License (the License). You may not use this file except in compliance with the
* License.
*
* You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
* specific language governing permission and limitations under the License.
*
* When distributing Covered Software, include this CDDL Header Notice in each file and include
* the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
* Header, with the fields enclosed by brackets [] replaced by your own identifying
* information: "Portions copyright [year] [name of copyright owner]".
*
* Copyright 2016 ForgeRock AS.
*
* Portions Copyright 2014 Nathaniel McCallum, Red Hat
*/
#import "FRAOathCode.h"
@implementation FRAOathCode
#pragma mark -
#pragma mark Class Methods
+ (NSString *)hmac:(CCHmacAlgorithm)algorithm codeLength:(uint8_t)codeLength key:(NSData *)key counter:(uint64_t) counter {
#ifdef __LITTLE_ENDIAN__
// Network byte order
counter = (((uint64_t) htonl(counter)) << 32) + htonl(counter >> 32);
#endif
// Create digits divisor
uint32_t div = 1;
for (int i = codeLength; i > 0; i--) {
div *= 10;
}
// Create the HMAC
int length = [self getDigestLength:algorithm];
uint8_t digest[length];
CCHmac(algorithm, [key bytes], [key length], &counter, sizeof(counter), digest);
// Truncate
uint32_t binary;
uint32_t off = digest[sizeof(digest) - 1] & 0xf;
binary = (digest[off + 0] & 0x7f) << 0x18;
binary |= (digest[off + 1] & 0xff) << 0x10;
binary |= (digest[off + 2] & 0xff) << 0x08;
binary |= (digest[off + 3] & 0xff) << 0x00;
binary = binary % div;
return [NSString stringWithFormat:[NSString stringWithFormat:@"%%0%hhulu", codeLength], binary];
}
+ (NSString *)asString:(CCHmacAlgorithm)algorithm {
if (algorithm == kCCHmacAlgMD5) {
return @"md5";
}
if (algorithm == kCCHmacAlgSHA256) {
return @"sha256";
}
if (algorithm == kCCHmacAlgSHA512) {
return @"sha512";
}
return @"sha1";
}
+ (CCHmacAlgorithm)fromString:(NSString *)string {
if ([string isEqual: @"md5"]) {
return kCCHmacAlgMD5;
}
if ([string isEqual: @"sha256"]) {
return kCCHmacAlgSHA256;
}
if ([string isEqual: @"sha512"]) {
return kCCHmacAlgSHA512;
}
return kCCHmacAlgSHA1;
}
+ (int)getDigestLength:(CCHmacAlgorithm)algorithm {
switch (algorithm) {
case kCCHmacAlgMD5:
return CC_MD5_DIGEST_LENGTH;
case kCCHmacAlgSHA256:
return CC_SHA256_DIGEST_LENGTH;
case kCCHmacAlgSHA512:
return CC_SHA512_DIGEST_LENGTH;
case kCCHmacAlgSHA1:
default:
return CC_SHA1_DIGEST_LENGTH;
}
}
@end