diff options
Diffstat (limited to 'crypto/blowfish_generic.c')
| -rw-r--r-- | crypto/blowfish_generic.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/crypto/blowfish_generic.c b/crypto/blowfish_generic.c new file mode 100644 index 000000000..0e74c7242 --- /dev/null +++ b/crypto/blowfish_generic.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Cryptographic API. + * + * Blowfish Cipher Algorithm, by Bruce Schneier. + * http://www.counterpane.com/blowfish.html + * + * Adapted from Kerneli implementation. + * + * Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org> + * Copyright (c) Kyle McMartin <kyle@debian.org> + * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> + */ + +#include <crypto/algapi.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <asm/unaligned.h> +#include <linux/types.h> +#include <crypto/blowfish.h> + +/* + * Round loop unrolling macros, S is a pointer to a S-Box array + * organized in 4 unsigned longs at a row. + */ +#define GET32_3(x) (((x) & 0xff)) +#define GET32_2(x) (((x) >> (8)) & (0xff)) +#define GET32_1(x) (((x) >> (16)) & (0xff)) +#define GET32_0(x) (((x) >> (24)) & (0xff)) + +#define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \ + S[512 + GET32_2(x)]) + S[768 + GET32_3(x)]) + +#define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); }) + +static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) +{ + struct bf_ctx *ctx = crypto_tfm_ctx(tfm); + const u32 *P = ctx->p; + const u32 *S = ctx->s; + u32 yl = get_unaligned_be32(src); + u32 yr = get_unaligned_be32(src + 4); + + ROUND(yr, yl, 0); + ROUND(yl, yr, 1); + ROUND(yr, yl, 2); + ROUND(yl, yr, 3); + ROUND(yr, yl, 4); + ROUND(yl, yr, 5); + ROUND(yr, yl, 6); + ROUND(yl, yr, 7); + ROUND(yr, yl, 8); + ROUND(yl, yr, 9); + ROUND(yr, yl, 10); + ROUND(yl, yr, 11); + ROUND(yr, yl, 12); + ROUND(yl, yr, 13); + ROUND(yr, yl, 14); + ROUND(yl, yr, 15); + + yl ^= P[16]; + yr ^= P[17]; + + put_unaligned_be32(yr, dst); + put_unaligned_be32(yl, dst + 4); +} + +static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) +{ + struct bf_ctx *ctx = crypto_tfm_ctx(tfm); + const u32 *P = ctx->p; + const u32 *S = ctx->s; + u32 yl = get_unaligned_be32(src); + u32 yr = get_unaligned_be32(src + 4); + + ROUND(yr, yl, 17); + ROUND(yl, yr, 16); + ROUND(yr, yl, 15); + ROUND(yl, yr, 14); + ROUND(yr, yl, 13); + ROUND(yl, yr, 12); + ROUND(yr, yl, 11); + ROUND(yl, yr, 10); + ROUND(yr, yl, 9); + ROUND(yl, yr, 8); + ROUND(yr, yl, 7); + ROUND(yl, yr, 6); + ROUND(yr, yl, 5); + ROUND(yl, yr, 4); + ROUND(yr, yl, 3); + ROUND(yl, yr, 2); + + yl ^= P[1]; + yr ^= P[0]; + + put_unaligned_be32(yr, dst); + put_unaligned_be32(yl, dst + 4); +} + +static struct crypto_alg alg = { + .cra_name = "blowfish", + .cra_driver_name = "blowfish-generic", + .cra_priority = 100, + .cra_flags = CRYPTO_ALG_TYPE_CIPHER, + .cra_blocksize = BF_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct bf_ctx), + .cra_module = THIS_MODULE, + .cra_u = { .cipher = { + .cia_min_keysize = BF_MIN_KEY_SIZE, + .cia_max_keysize = BF_MAX_KEY_SIZE, + .cia_setkey = blowfish_setkey, + .cia_encrypt = bf_encrypt, + .cia_decrypt = bf_decrypt } } +}; + +static int __init blowfish_mod_init(void) +{ + return crypto_register_alg(&alg); +} + +static void __exit blowfish_mod_fini(void) +{ + crypto_unregister_alg(&alg); +} + +subsys_initcall(blowfish_mod_init); +module_exit(blowfish_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Blowfish Cipher Algorithm"); +MODULE_ALIAS_CRYPTO("blowfish"); +MODULE_ALIAS_CRYPTO("blowfish-generic"); |