change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/include/crypto/ctr.h
..
..
@@ -1,20 +1,65 @@
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+/* SPDX-License-Identifier: GPL-2.0-or-later */
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 /*
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  * CTR: Counter mode
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  *
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  * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
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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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 #ifndef _CRYPTO_CTR_H
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 #define _CRYPTO_CTR_H
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+#include <crypto/algapi.h>
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+#include <crypto/internal/skcipher.h>
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+#include <linux/string.h>
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+#include <linux/types.h>
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+
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 #define CTR_RFC3686_NONCE_SIZE 4
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 #define CTR_RFC3686_IV_SIZE 8
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 #define CTR_RFC3686_BLOCK_SIZE 16
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+static inline int crypto_ctr_encrypt_walk(struct skcipher_request *req,
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+					  void (*fn)(struct crypto_skcipher *,
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+						     const u8 *, u8 *))
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+{
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+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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+	int blocksize = crypto_skcipher_chunksize(tfm);
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+	u8 buf[MAX_CIPHER_BLOCKSIZE];
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+	struct skcipher_walk walk;
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+	int err;
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+
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+	/* avoid integer division due to variable blocksize parameter */
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+	if (WARN_ON_ONCE(!is_power_of_2(blocksize)))
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+		return -EINVAL;
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+
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+	err = skcipher_walk_virt(&walk, req, false);
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+
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+	while (walk.nbytes > 0) {
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+		u8 *dst = walk.dst.virt.addr;
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+		u8 *src = walk.src.virt.addr;
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+		int nbytes = walk.nbytes;
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+		int tail = 0;
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+
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+		if (nbytes < walk.total) {
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+			tail = walk.nbytes & (blocksize - 1);
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+			nbytes -= tail;
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+		}
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+
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+		do {
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+			int bsize = min(nbytes, blocksize);
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+
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+			fn(tfm, walk.iv, buf);
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+
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+			crypto_xor_cpy(dst, src, buf, bsize);
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+			crypto_inc(walk.iv, blocksize);
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+
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+			dst += bsize;
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+			src += bsize;
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+			nbytes -= bsize;
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+		} while (nbytes > 0);
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+
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+		err = skcipher_walk_done(&walk, tail);
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+	}
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+	return err;
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+}
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+
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 #endif  /* _CRYPTO_CTR_H */