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https://github.com/torvalds/linux
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50a3a9fae3
Instead of using an alignmask of 0x3 to ensure 32-bit alignment of the Blowfish input and output blocks, which propagates to mode drivers, and results in pointless copying on architectures that don't care about alignment, use the unaligned accessors, which will do the right thing on each respective architecture, avoiding the need for double buffering. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
133 lines
3.1 KiB
C
133 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Cryptographic API.
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*
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* Blowfish Cipher Algorithm, by Bruce Schneier.
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* http://www.counterpane.com/blowfish.html
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*
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* Adapted from Kerneli implementation.
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*
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* Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org>
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* Copyright (c) Kyle McMartin <kyle@debian.org>
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <asm/unaligned.h>
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#include <linux/crypto.h>
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#include <linux/types.h>
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#include <crypto/blowfish.h>
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/*
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* Round loop unrolling macros, S is a pointer to a S-Box array
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* organized in 4 unsigned longs at a row.
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*/
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#define GET32_3(x) (((x) & 0xff))
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#define GET32_2(x) (((x) >> (8)) & (0xff))
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#define GET32_1(x) (((x) >> (16)) & (0xff))
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#define GET32_0(x) (((x) >> (24)) & (0xff))
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#define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \
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S[512 + GET32_2(x)]) + S[768 + GET32_3(x)])
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#define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); })
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static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
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{
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struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
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const u32 *P = ctx->p;
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const u32 *S = ctx->s;
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u32 yl = get_unaligned_be32(src);
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u32 yr = get_unaligned_be32(src + 4);
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ROUND(yr, yl, 0);
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ROUND(yl, yr, 1);
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ROUND(yr, yl, 2);
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ROUND(yl, yr, 3);
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ROUND(yr, yl, 4);
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ROUND(yl, yr, 5);
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ROUND(yr, yl, 6);
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ROUND(yl, yr, 7);
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ROUND(yr, yl, 8);
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ROUND(yl, yr, 9);
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ROUND(yr, yl, 10);
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ROUND(yl, yr, 11);
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ROUND(yr, yl, 12);
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ROUND(yl, yr, 13);
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ROUND(yr, yl, 14);
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ROUND(yl, yr, 15);
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yl ^= P[16];
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yr ^= P[17];
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put_unaligned_be32(yr, dst);
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put_unaligned_be32(yl, dst + 4);
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}
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static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
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{
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struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
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const u32 *P = ctx->p;
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const u32 *S = ctx->s;
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u32 yl = get_unaligned_be32(src);
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u32 yr = get_unaligned_be32(src + 4);
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ROUND(yr, yl, 17);
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ROUND(yl, yr, 16);
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ROUND(yr, yl, 15);
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ROUND(yl, yr, 14);
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ROUND(yr, yl, 13);
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ROUND(yl, yr, 12);
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ROUND(yr, yl, 11);
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ROUND(yl, yr, 10);
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ROUND(yr, yl, 9);
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ROUND(yl, yr, 8);
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ROUND(yr, yl, 7);
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ROUND(yl, yr, 6);
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ROUND(yr, yl, 5);
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ROUND(yl, yr, 4);
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ROUND(yr, yl, 3);
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ROUND(yl, yr, 2);
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yl ^= P[1];
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yr ^= P[0];
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put_unaligned_be32(yr, dst);
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put_unaligned_be32(yl, dst + 4);
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}
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static struct crypto_alg alg = {
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.cra_name = "blowfish",
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.cra_driver_name = "blowfish-generic",
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.cra_priority = 100,
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.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
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.cra_blocksize = BF_BLOCK_SIZE,
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.cra_ctxsize = sizeof(struct bf_ctx),
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.cra_module = THIS_MODULE,
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.cra_u = { .cipher = {
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.cia_min_keysize = BF_MIN_KEY_SIZE,
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.cia_max_keysize = BF_MAX_KEY_SIZE,
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.cia_setkey = blowfish_setkey,
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.cia_encrypt = bf_encrypt,
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.cia_decrypt = bf_decrypt } }
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};
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static int __init blowfish_mod_init(void)
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{
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return crypto_register_alg(&alg);
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}
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static void __exit blowfish_mod_fini(void)
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{
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crypto_unregister_alg(&alg);
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}
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subsys_initcall(blowfish_mod_init);
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module_exit(blowfish_mod_fini);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Blowfish Cipher Algorithm");
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MODULE_ALIAS_CRYPTO("blowfish");
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MODULE_ALIAS_CRYPTO("blowfish-generic");
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