91 lines
1.9 KiB
C
91 lines
1.9 KiB
C
/*
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* Cryptographic API.
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*
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* CRC32.
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*
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* Derived from cryptoapi implementation, adapted for in-place
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* scatterlist interface.
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*
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* Copyright (c) Alan Smithee.
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* Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
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* Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <common.h>
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#include <digest.h>
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#include <init.h>
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#include <linux/string.h>
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#include <crc.h>
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#include <asm/unaligned.h>
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#include <asm/byteorder.h>
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#include <crypto/crc.h>
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#include <crypto/internal.h>
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static int crc32_init(struct digest *desc)
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{
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struct crc32_state *ctx = digest_ctx(desc);
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ctx->crc = 0;
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return 0;
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}
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static int crc32_update(struct digest *desc, const void *data,
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unsigned long len)
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{
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struct crc32_state *ctx = digest_ctx(desc);
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while (len) {
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int now = min((ulong)4096, len);
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ctx->crc = crc32(ctx->crc, data, now);
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len -= now;
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data += now;
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}
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return 0;
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}
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static int crc32_final(struct digest *desc, unsigned char *md)
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{
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struct crc32_state *ctx = digest_ctx(desc);
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__be32 *dst = (__be32 *)md;
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/* Store state in digest */
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dst[0] = cpu_to_be32(ctx->crc);
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/* Wipe context */
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memset(ctx, 0, sizeof *ctx);
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return 0;
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}
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static struct digest_algo m = {
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.base = {
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.name = "crc32",
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.driver_name = "crc32-generic",
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.priority = 0,
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.algo = HASH_ALGO_CRC32,
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},
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.init = crc32_init,
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.update = crc32_update,
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.final = crc32_final,
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.digest = digest_generic_digest,
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.verify = digest_generic_verify,
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.length = CRC32_DIGEST_SIZE,
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.ctx_length = sizeof(struct crc32_state),
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};
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static int crc32_digest_register(void)
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{
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return digest_algo_register(&m);
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}
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device_initcall(crc32_digest_register);
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