OFHMAC.h

/*
 * Copyright (c) 2008-2026 Jonathan Schleifer <js@nil.im>
 *
 * All rights reserved.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 3.0 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * version 3.0 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3.0 along with this program. If not, see
 * <https://www.gnu.org/licenses/>.
 */
 
#import "OFObject.h"
#import "OFCryptographicHash.h"
 
OF_ASSUME_NONNULL_BEGIN

OF_SUBCLASSING_RESTRICTED
@interface OFHMAC: OFObject
{
    Class <OFCryptographicHash> _hashClass;
    bool _allowsSwappableMemory;
    id <OFCryptographicHash> _Nullable _outerHash, _innerHash;
    id <OFCryptographicHash> _Nullable _outerHashCopy, _innerHashCopy;
    bool _calculated;
}

@property (readonly, nonatomic) Class <OFCryptographicHash> hashClass;

@property (readonly, nonatomic) bool allowsSwappableMemory;

@property (readonly, nonatomic) const unsigned char *digest
    OF_RETURNS_INNER_POINTER;

@property (readonly, nonatomic) size_t digestSize;

+ (instancetype)HMACWithHashClass: (Class <OFCryptographicHash>)hashClass
        allowsSwappableMemory: (bool)allowsSwappableMemory;
 
- (instancetype)init OF_UNAVAILABLE;

- (instancetype)initWithHashClass: (Class <OFCryptographicHash>)hashClass
        allowsSwappableMemory: (bool)allowsSwappableMemory
    OF_DESIGNATED_INITIALIZER;

- (void)setKey: (const void *)key length: (size_t)length;

- (void)updateWithBuffer: (const void *)buffer length: (size_t)length;

- (void)calculate;

- (void)reset;

- (void)zero;
@end
 
OF_ASSUME_NONNULL_END