ccdigest_final_64be.c   [plain text]

/*
 *  ccdigest_final_64be.c
 *  corecrypto
 *
 *  Created on 12/06/2010
 *
 *  Copyright (c) 2010,2011,2015 Apple Inc. All rights reserved.
 *
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
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 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <corecrypto/ccdigest_priv.h>
#include <corecrypto/cc_priv.h>
#include "ccdigest_internal.h"

/* This can be used for SHA1, SHA256 and SHA224 */
void
ccdigest_final_64be(const struct ccdigest_info *di, ccdigest_ctx_t ctx, unsigned char *digest)
{
	// Sanity check to recover from ctx corruptions.
	if (ccdigest_num(di, ctx) >= di->block_size) {
		ccdigest_num(di, ctx) = 0;
	}

	// Clone the state.
	ccdigest_di_decl(di, tmp);
	cc_memcpy(tmp, ctx, ccdigest_di_size(di));

	ccdigest_nbits(di, tmp) += ccdigest_num(di, tmp) * 8;
	ccdigest_data(di, tmp)[ccdigest_num(di, tmp)++] = 0x80;

	/* If we don't have at least 8 bytes (for the length) left we need to add
	 *  a second block. */
	if (ccdigest_num(di, tmp) > 64 - 8) {
		while (ccdigest_num(di, tmp) < 64) {
			ccdigest_data(di, tmp)[ccdigest_num(di, tmp)++] = 0;
		}
		di->compress(ccdigest_state(di, tmp), 1, ccdigest_data(di, tmp));
		ccdigest_num(di, tmp) = 0;
	}

	/* pad upto block_size minus 8 with 0s */
	while (ccdigest_num(di, tmp) < 64 - 8) {
		ccdigest_data(di, tmp)[ccdigest_num(di, tmp)++] = 0;
	}

	CC_STORE64_BE(ccdigest_nbits(di, tmp), ccdigest_data(di, tmp) + 64 - 8);
	di->compress(ccdigest_state(di, tmp), 1, ccdigest_data(di, tmp));

	/* copy output */
	for (unsigned int i = 0; i < di->output_size / 4; i++) {
		CC_STORE32_BE(ccdigest_state_u32(di, tmp)[i], digest + (4 * i));
	}

	ccdigest_di_clear(di, tmp);
}